WO2011099300A1

WO2011099300A1 - Terminal apparatus and signal transmission control method

Info

Publication number: WO2011099300A1
Application number: PCT/JP2011/000772
Authority: WO
Inventors: 中尾正悟; 今村大地; 西尾昭彦
Original assignee: パナソニック株式会社
Priority date: 2010-02-12
Filing date: 2011-02-10
Publication date: 2011-08-18

Abstract

Provided is a terminal apparatus whereby, even when SR occurs, on the terminal side, in a subframe in which a base station is to receive a response signal from the terminal in an LTE-A system, the base station can determine whether downstream allocation control information has successfully been received on the terminal side, thereby improving the retransmission efficiency. The terminal apparatus (200), which is operative to allocate one of a response signal and SR to code resources and transmit, via a plurality of antennas, the response signal or SR allocated to the code resources, comprises a control unit (208) that, when SR and a response signal concurrently occur within a transmission unit time, transmits the response signal by use of both at least one of SR resources to which SR is to be allocated when only SR occurs within the transmission unit time and at least one of ACK/NACK resources to which a response signal is to be allocated when only the response signal occurs within the transmission unit time.

Description

Terminal apparatus and signal transmission control method

The present invention relates to a terminal device and a signal transmission control method.

In 3GPP LTE, OFDMA (Orthogonal Frequency Division Multiple Access) is adopted as a downlink communication method. In a wireless communication system to which 3GPP LTE is applied, a base station transmits a synchronization signal (Synchronization Channel: SCH) and a broadcast signal (Broadcast Channel: BCH) using predetermined communication resources. The terminal first secures synchronization with the base station by capturing the SCH. Thereafter, the terminal acquires parameters (eg, frequency bandwidth) unique to the base station by reading the BCH information (see Non-Patent Documents 1, 2, and 3).

The terminal establishes communication with the base station by making a connection request to the base station after the acquisition of the parameters unique to the base station is completed. The base station transmits control information via a PDCCH (Physical 確立 Downlink Control CHannel) as necessary to a terminal with which communication has been established.

Then, the terminal performs “blind determination” for each of the plurality of control information included in the received PDCCH signal. That is, the control information includes a CRC (Cyclic Redundancy Check) part, and this CRC part is masked by the terminal ID of the transmission target terminal in the base station. Therefore, the terminal cannot determine whether or not the received control information is control information destined for the own device until the CRC part of the received control information is demasked with the terminal ID of the own device. In this blind determination, if the CRC calculation is OK as a result of demasking, it is determined that the control information is addressed to the own device.

In 3GPP LTE, ARQ (Automatic Repeat Request) is applied to downlink data from the base station to the terminal. That is, the terminal feeds back a response signal indicating an error detection result of downlink data to the base station. The terminal performs CRC on the downlink data, and if CRC = OK (no error), ACK (Acknowledgment) is sent to the base station as a response signal, and if CRC = NG (error is found), NACK (Negative Acknowledgment) is sent to the base station as a response signal. provide feedback. However, BPSK (Binary Phase Shift Shift Keying) is used to modulate the response signal (that is, ACK / NACK signal). Further, an uplink control channel such as PUCCH (Physical-Uplink-Control-Channel) is used for feedback of the response signal. If the received response signal indicates NACK, the base station transmits retransmission data to the terminal.

Here, the control information (that is, downlink allocation control information) transmitted from the base station includes resource allocation information including resource information allocated to the terminal by the base station. As described above, the PDCCH is used for transmitting the control information. This PDCCH is composed of one or a plurality of L1 / L2 CCHs (L1 / L2 Control Channel). Each L1 / L2CCH is composed of one or a plurality of CCEs (Control Channel Element). That is, CCE is a basic unit for mapping control information to PDCCH. When one L1 / L2CCH is composed of a plurality of CCEs, a plurality of CCEs having consecutive identification numbers (Index) are assigned to the L1 / L2CCH. The base station allocates L1 / L2 CCH to the resource allocation target terminal according to the number of CCEs required for reporting control information to the resource allocation target terminal. Then, the base station maps the physical resource corresponding to the CCE of this L1 / L2CCH and transmits control information.

Also, here, each CCE is associated with the PUCCH configuration resource on a one-to-one basis. Therefore, the terminal that has received the L1 / L2CCH can implicitly specify the configuration resource of the PUCCH corresponding to the CCE that configures the L1 / L2CCH, and uses this specified resource to transmit a response signal. Transmit to the base station. However, when the L1 / L2 CCH occupies a plurality of continuous CCEs, the terminal may use one of a plurality of PUCCH configuration resources corresponding to the plurality of CCEs (for example, a PUCCH configuration corresponding to the CCE having the smallest Index). Resource) is used to transmit a response signal to the base station. Thus, downlink communication resources are efficiently used.

As shown in FIG. 1, a plurality of response signals transmitted from a plurality of terminals include a ZAC (Zero Auto-correlation) sequence having a Zero Auto-correlation characteristic on the time axis, a Walsh sequence, and a DFT ( Discrete Fourier Transform) sequence and code-multiplexed in PUCCH. In FIG. 1, (W ₀ , W ₁ , W ₂ , W ₃ ) represents a Walsh sequence with a sequence length of 4, and (F ₀ , F ₁ , F ₂ ) represents a DFT sequence with a sequence length of 3. As shown in FIG. 1, in the terminal, an ACK or NACK response signal is first spread in a 1SC-FDMA symbol by a ZAC sequence (sequence length 12) on the frequency axis. Next, the response signal after first spreading is subjected to IFFT (Inverse Fast Fourier Transform) corresponding to W ₀ to W ₃ and F ₀ to F _2, respectively. A response signal spread by a ZAC sequence having a sequence length of 12 on the frequency axis is converted into a ZAC sequence having a sequence length of 12 on the time axis by the IFFT. The signal after IFFT is further subjected to second order spreading using a Walsh sequence (sequence length 4) and a DFT sequence (sequence length 3).

Here, between response signals transmitted from different terminals, sequences corresponding to different cyclic shift amounts (Cyclic shift Index) or different orthogonal code sequences (Orthogonal cover Index: OC Index) (that is, Walsh sequences and DFT sequences) Set). Therefore, the base station can separate a plurality of response signals that are code-multiplexed by using conventional despreading processing and correlation processing (see Non-Patent Document 4).

However, since each terminal blindly determines downlink allocation control information addressed to itself in each subframe (transmission unit time), reception of downlink allocation control information is not always successful on the terminal side. When a terminal fails to receive downlink assignment control information addressed to itself in a certain downlink unit band, the terminal cannot even know whether downlink data addressed to itself exists in the downlink unit band. Therefore, when the terminal fails to receive downlink allocation control information in a certain downlink unit band, the terminal does not generate a response signal for downlink data in the downlink unit band. This error case is defined as DTX (DTX (Discontinuous transmission) of ACK / NACK signals) of the response signal in the sense that the response signal is not transmitted on the terminal side.

In addition, standardization of 3GPP LTE-Advanced, which realizes higher communication speed than 3GPP LTE, has started. The 3GPP LTE-Advanced system (hereinafter sometimes referred to as “LTE-A system”) follows the 3GPP LTE system (hereinafter sometimes referred to as “LTE system”). In 3GPP LTE-Advanced, a base station and a terminal capable of communicating in a wideband frequency of 40 MHz or more are expected to be introduced in order to realize a downlink transmission speed of 1 Gbps or more at the maximum.

In the LTE-A system, in order to simultaneously realize communication at an ultra-high transmission rate several times the transmission rate in the LTE system and backward compatibility with the LTE system, the bandwidth for the LTE-A system is changed to LTE. It is divided into “unit bands” of 20 MHz or less, which is the support bandwidth of the system. That is, the “unit band” is a band having a maximum width of 20 MHz, and is defined as a basic unit of the communication band. Furthermore, the “unit band” (hereinafter referred to as “downlink unit band”) in the downlink is a band delimited by downlink frequency band information in the BCH broadcast from the base station, or the downlink control channel (PDCCH) is a frequency. It may be defined as a band defined by a dispersion width when distributed in a region. Also, the “unit band” (hereinafter referred to as “uplink unit band”) in the uplink is a band delimited by uplink frequency band information in the BCH broadcast from the base station, or a PUSCH (Physical-Uplink) near the center. It may be defined as a basic unit of a communication band of 20 MHz or less including a Shared (CHAnel) region and including PUCCH for LTE at both ends. In addition, the “unit band” may be expressed as “Component Carrier (s)” in English in 3GPP LTE-Advanced.

By the way, the above-described uplink control channel (PUCCH) may be expressed as SR (Scheduling Request) (SRI: Scheduling Request Indicator) which is an uplink control signal indicating the generation of uplink data to be transmitted from the terminal side. ) Transmission. When establishing a connection with a terminal, the base station individually allocates a resource to be used for SR transmission (hereinafter referred to as SR resource) to each terminal. Moreover, OOK (On-Off-Keying) is applied to this SR, and the base station side determines the SR from the terminal based on whether or not the terminal transmits an arbitrary signal using the SR resource. Is detected. In addition, spreading using a ZAC sequence, a Walsh sequence, and a DFT sequence is applied to SR similarly to the response signal described above.

In the LTE system, SR and response signal may occur within the same subframe. In this case, when the terminal and the response signal are code-multiplexed and transmitted on the terminal side, the PAPR (Peak-to-Average-Power-Ratio) of the composite waveform of the signal transmitted by the terminal is greatly deteriorated. However, in the LTE system, since the amplifier efficiency of the terminal is regarded as important, when the SR and the response signal are generated in the same subframe on the terminal side, the terminal should use the resource (hereinafter, referred to as the resource to be transmitted). The response signal is transmitted using SR resources individually allocated in advance for each terminal without using ACK / NACK resources). As a result, the PAPR of the composite waveform of the signal transmitted by the terminal can be kept low. At this time, the base station side detects the SR from the terminal side based on whether or not the SR resource is used. Further, on the base station side, based on the phase of the signal transmitted with the SR resource (or the ACK / NACK resource when SR resource is not used) (that is, the BPSK demodulation result), the terminal performs ACK or NACK. Determine which one was sent.

Here, the operation related to the transmission of the SR and the response signal on the terminal side in the LTE system described above will be described with reference to FIGS. In FIG. 2, ACK / NACK resources and SR resources are allocated to different code resources. In the downlink unit band shown in FIG. 2, the base station uses the L1 / L2CCH (channel constituted by one or a plurality of CCEs) included in the PDCCH to indicate downlink allocation control indicating resources for transmitting downlink data. Send information. Further, as shown in FIG. 2, the base station allocates in advance one arbitrary PUCCH resource included in the PUCCH of the uplink unit band as a PUCCH resource (SR resource) for SR. Also, the terminal uses one PUCCH resource associated with the CCE (PDCCH) occupied by the downlink allocation control information in the downlink unit band as a PUCCH resource (ACK / NACK resource) for response signals.

First, as shown in FIG. 3A, when the terminal transmits the SR and the response signal simultaneously in a certain subframe (that is, when transmitting SR + ACK or SR + NACK), the terminal transmits the downlink data channel ( A response signal ("A / N") for downlink data (DL data) received by PDSCH is assigned to one SR resource included in the PUCCH of the uplink unit band shown in FIG. 3A. And a terminal determines the phase of the signal transmitted using SR resource according to whether a response signal is ACK or NACK.

Next, as shown in FIG. 3B, when the terminal transmits only a response signal within a certain subframe (that is, when only ACK or NACK is transmitted), the terminal receives the downlink received on the PDSCH shown in FIG. A response signal ("A / N") for data (DL data) is allocated to one ACK / NACK resource included in the PUCCH of the uplink unit band shown in FIG. 3B. And a terminal determines the phase of the signal transmitted using an ACK / NACK resource according to whether a response signal is ACK or NACK.

Next, as illustrated in FIG. 3C, when the terminal transmits only SR within a certain subframe, the terminal allocates SR to one SR resource included in the PUCCH of the uplink unit band illustrated in FIG. 3C. Then, the terminal sets a NACK phase point for the SR resource.

However, as described above, since the terminal side does not always succeed in receiving downlink allocation control information, there is a difference in recognition regarding the success or failure of downlink signal reception at the terminal side between the base station side and the terminal side. there is a possibility. Specifically, when the base station transmits downlink allocation control information (and downlink data) to the terminal, when the terminal transmits an uplink signal using SR resources, not only the SR detection is performed on the base station side, It is determined whether the phase of the signal allocated to the SR resource indicates ACK or NACK information. However, when reception of downlink allocation control information has failed on the terminal side (that is, when DTX occurs), the terminal transmits using SR resources without including response signal information in the uplink signal. . Therefore, in the LTE system, as shown in FIG. 3, when the terminal notifies only the SR to the base station (FIG. 3C), the SR and NACK information are simultaneously transmitted to the base station so that these recognition differences do not become a big problem. The same signal point (that is, the phase point of NACK) is used. By doing so, even if the terminal fails to receive the downlink allocation control information and notifies only the SR (that is, when transmitting SR + DTX), the base station transmits the signal and the SR and NACK information at the same time. Therefore, the downlink data retransmission control can be executed without any major problem.

Furthermore, in the LTE-A system, it is assumed that the terminal includes a plurality of transmission antennas, and SCTD (Space Code Transmit Diversity.) Using a plurality of different code resources for the SR or response signal. Application of SORTD (sometimes called Spatial Orthogonal-Resource Transmit Diversity) is being studied. In SCTD, for example, the base station allocates two ACK / NACK resources to one response signal, and the terminal transmits the same response signal respectively allocated to different code resources by two antennas (non-patent). Reference 5).

Also, in LTE and LTE-A systems, hybrid ARQ (Hybrid ARQ: HARQ) that combines ARQ and error correction is applied. In HARQ, when data to be retransmitted is received, the reception quality on the receiving side can be improved by combining the retransmitted data and the data including the error received last time. For example, IR (Incremental Redundancy) is known as one of the efficient data retransmission methods in HARQ (see Non-Patent Document 6).

As described above, in the LTE system, the case where the terminal transmits only SR (SR + DTX transmission) (FIG. 3C) and the case where the terminal transmits SR and NACK information simultaneously (SR + NACK transmission) (FIG. 3A) are the same. Information is notified by the same phase point (that is, the phase point of NACK) using the resource (that is, SR resource). Therefore, when the downlink data is actually transmitted to the terminal on the base station side, the base station fails to receive the downlink allocation control information on the terminal side, and SR is generated on the terminal side (that is, SR + DTX (Hereinafter referred to as “(SR + DTX)”), the terminal side successfully received the downlink allocation control information, but detected CRC = NG for the downlink data and an SR occurred on the terminal side It is not possible to determine whether the state is (ie, SR + NACK transmission; hereinafter referred to as “(SR + NACK)”).

Here, in order to apply IR, which is one of the excellent retransmission methods in HARQ, the terminal side has successfully received downlink allocation control information at the previous transmission, and the terminal has received downlink data (including errors). ) Must be recognizable on the base station side. However, as described above, when the terminal side notifies information using the NACK phase point in the SR resource, the base station cannot distinguish between the (SR + NACK) state and the (SR + DTX) state, that is, Whether or not the downlink allocation control information is received on the terminal side cannot be determined. If the base station cannot determine whether or not the downlink allocation control information is received successfully on the terminal side, the base station simply transmits the same information as the previous transmission at the time of retransmission (and is therefore less efficient than IR). The problem arises that only control is possible. In other words, in the LTE system, the base station uses a subframe in which the base station should receive a response signal from the terminal (that is, a subframe in which a response signal is transmitted if the terminal has received downlink allocation control information correctly). When SR occurs on the terminal side, the base station may not be able to determine whether the terminal side has received downlink allocation control information, and there is a problem that efficient retransmission control by IR or the like cannot be performed.

An object of the present invention is to provide a subframe in which a base station should receive a response signal from a terminal (that is, a subframe in which a response signal is transmitted if the terminal has correctly received downlink allocation control information) in the LTE-A system. Provided is a terminal device and a signal transmission control method capable of improving the retransmission efficiency by allowing the base station to determine whether or not the terminal side has received downlink allocation control information even when SR occurs in the terminal. It is to be.

The terminal apparatus of the present invention allocates either one of a response signal based on an error detection result of downlink data or an uplink control signal indicating the occurrence of uplink data to a code resource, and the response signal assigned to the code resource or A terminal device for transmitting uplink control signals from a plurality of antennas, receiving means for receiving the downlink data assigned to a downlink data channel, and generating the response signal based on an error detection result of the downlink data Means, transmission means for transmitting the response signal or the uplink control signal using the code resource, and transmission of the response signal or the uplink control signal based on the generation status of the response signal and the uplink control signal And a control means for controlling the uplink control signal and the response signal within a transmission unit time. If only the uplink control signal is generated within the transmission unit time, at least one resource among the first code resources to which the uplink control signal is allocated and the transmission unit time When only the response signal is generated, the response signal is transmitted using at least one resource among the second code resources to which the response signal is assigned.

The signal transmission control method of the present invention assigns either one of a response signal based on an error detection result of downlink data or an uplink control signal indicating the occurrence of uplink data to a code resource, and the response assigned to the code resource A signal transmission control method in a terminal device for transmitting a signal or an uplink control signal from a plurality of antennas, respectively, based on a reception step of receiving the downlink data assigned to a downlink data channel and an error detection result of the downlink data Based on the generation step of generating the response signal, the transmission step of transmitting the response signal or the uplink control signal using the code resource, and the occurrence status of the response signal and the uplink control signal, the response signal Or a control step for controlling transmission of the uplink control signal, the control step comprising A first code resource to which the uplink control signal is allocated when only the uplink control signal is generated within the transmission unit time when the uplink control signal and the response signal are generated simultaneously within the transmission unit time And at least one resource among second code resources to which the response signal is assigned when only the response signal is generated within the transmission unit time, and The response signal is transmitted.

According to the present invention, in the LTE-A system, a subframe in which a base station should receive a response signal from a terminal (that is, a subframe in which a response signal is transmitted if the terminal has correctly received downlink allocation control information). Even when SR occurs on the terminal side, the base station can determine whether or not the terminal side has received downlink allocation control information, and retransmission efficiency can be improved.

The figure which shows the spreading | diffusion method of a response signal and a reference signal The figure which shows the operation | movement regarding transmission of SR and a response signal by the terminal side The figure which shows the transmission control process of the terminal according to the generation condition of SR, and the generation condition of a response signal The block diagram which shows the structure of the base station which concerns on Embodiment 1 of this invention. The block diagram which shows the structure of the terminal which concerns on Embodiment 1 of this invention. The figure which shows SR resource which concerns on Embodiment 1 of this invention. The figure which shows the operation | movement of the terminal which concerns on Embodiment 1 of this invention (when the number of SR resources: 2 and the number of ACK / NACK resources: 2) The figure which shows the operation | movement of the terminal which concerns on Embodiment 1 of this invention (when the number of SR resources: 2 and the number of ACK / NACK resources: 1) The figure which shows the operation | movement of the terminal which concerns on Embodiment 1 of this invention (when the number of SR resources is 1 piece and the number of ACK / NACK resources is 2 pieces) The figure which shows the likelihood determination process in the base station which concerns on Embodiment 2 of this invention. The figure which shows the synthetic | combination process in the base station which concerns on Embodiment 2 of this invention. The block diagram which shows the structure of the base station which concerns on Embodiment 2 of this invention. The block diagram which shows the structure of the terminal which concerns on Embodiment 2 of this invention. The figure which shows operation | movement of the terminal which concerns on Embodiment 2 of this invention. The figure which shows the synthetic | combination process in the base station which concerns on Embodiment 2 of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that, in each embodiment, the same components are denoted by the same reference numerals, and the description thereof is omitted because it is redundant.

(Embodiment 1)
[Base station configuration]
FIG. 4 is a block diagram showing a configuration of base station 100 according to the present embodiment. In FIG. 4, the base station 100 includes a control unit 101, a control information generation unit 102, an encoding unit 103, a modulation unit 104, an encoding unit 105, a data transmission control unit 106, a modulation unit 107, Mapping unit 108, IFFT unit 109, CP adding unit 110, radio transmitting unit 111, radio receiving unit 112, CP removing unit 113, PUCCH extracting unit 114, despreading unit 115, and sequence control unit 116 A correlation processing unit 117, a determination unit 118, and a retransmission control signal generation unit 119.

The control unit 101 transmits a downlink resource (that is, downlink control information allocation resource) for transmitting control information and downlink data included in the control information to a resource allocation target terminal 200 to be described later. To allocate (assign) downlink resources (that is, downlink data allocation resources). Further, the downlink control information allocation resource is selected in a resource corresponding to the downlink control channel (PDCCH) in the downlink unit band. Further, the downlink data allocation resource is selected in a resource corresponding to the downlink data channel (PDSCH) in the downlink unit band. When there are a plurality of resource allocation target terminals 200, the control unit 101 allocates different resources to each of the resource allocation target terminals 200.

The downlink control information allocation resource is equivalent to the above-mentioned L1 / L2CCH. That is, the downlink control information allocation resource is composed of one or a plurality of CCEs. Further, each CCE included in the downlink control information allocation resource is associated with the configuration resource of the uplink control channel (PUCCH) on a one-to-one basis. However, the association between the CCE and the PUCCH configuration resource is made by associating the downlink unit band and the uplink unit band broadcasted for the LTE system.

Also, the control unit 101 determines a coding rate used when transmitting control information to the resource allocation target terminal 200. Since the data amount of control information differs according to the coding rate, downlink control information allocation resources having a number of CCEs to which control information of this data amount can be mapped are allocated by the control unit 101.

And the control part 101 outputs the information regarding a downlink data allocation resource with respect to the control information generation part 102. FIG. In addition, the control unit 101 outputs information on the coding rate used when transmitting control information to the coding unit 103. Control section 101 also determines the coding rate of transmission data (that is, downlink data) and outputs the coding rate to coding section 105. In addition, the control unit 101 outputs information on the downlink data allocation resource and the downlink control information allocation resource to the mapping unit 108.

The control information generation unit 102 generates control information including downlink data allocation resources and outputs the control information to the encoding unit 103. Further, when there are a plurality of resource allocation target terminals 200, the control information includes the terminal ID of the destination terminal in order to distinguish the resource allocation target terminals 200 from each other. For example, CRC bits masked with the terminal ID of the destination terminal are included in the control information. This control information may be referred to as “downlink allocation control information”.

The encoding unit 103 encodes the control information input from the control information generation unit 102 according to the encoding rate received from the control unit 101, and outputs the encoded control information to the modulation unit 104.

Modulation section 104 modulates the encoded control information and outputs the obtained modulated signal to mapping section 108.

Encoding section 105 receives transmission data (that is, downlink data) for each transmission destination terminal 200 and encoding rate information from control section 101, and encodes transmission data at the encoding rate indicated by the encoding rate information. And output to the data transmission control unit 106.

The data transmission control unit 106 holds the encoded transmission data and outputs the encoded transmission data to the modulation unit 107 during the initial transmission. The encoded transmission data is held for each transmission destination terminal 200. In addition, when the retransmission control signal received from retransmission control signal generation section 119 indicates a retransmission command, data transmission control section 106 outputs retained data corresponding to the retransmission control signal to modulation section 107. In addition, when the retransmission control signal received from the retransmission control signal generation unit 119 indicates that the retransmission control signal is not retransmitted, the data transmission control unit 106 deletes the retained data corresponding to the retransmission control signal. In this case, the data transmission control unit 106 outputs the next initial transmission data to the modulation unit 107.

Modulation section 107 modulates the encoded transmission data received from data transmission control section 106 and outputs the modulated signal to mapping section 108.

Mapping section 108 maps the modulation signal (downlink allocation control information) of the control information received from modulation section 104 to the resource (resource in PDCCH) indicated by the downlink control information allocation resource received from control section 101, and passes to IFFT section 109. Output.

Further, mapping section 108 maps the modulation signal (downlink data) of the transmission data received from modulation section 107 to the resource (resource in PDSCH) indicated by the downlink data allocation resource received from control section 101, and to IFFT section 109. Output.

Control information and transmission data (downlink data) mapped to a plurality of subcarriers in the downlink unit band by mapping section 108 are converted from frequency domain signals to time domain signals by IFFT section 109, and CP adding section 110 After the CP is added to form an OFDM signal, transmission processing such as D / A conversion, amplification, and up-conversion is performed by the wireless transmission unit 111 and transmitted to the terminal 200 via the antenna.

The radio reception unit 112 receives an uplink control channel signal (PUCCH signal) transmitted from the terminal 200 via an antenna, and performs reception processing such as down-conversion and A / D conversion on the received signal. Note that the PUCCH signal may include a response signal, SR, and a reference signal.

The CP removal unit 113 removes the CP added to the reception signal after the reception process.

The PUCCH extraction unit 114 extracts the SR resource and the ACK / NACK resource from the PUCCH signal included in the received signal, and distributes the PUCCH signal corresponding to the extracted resource for each processing system corresponding to each resource. In terminal 200, two ACK / NACK resources, one ACK / NACK resource, two SR resources, one SR resource, or two types of code resources different from each other in SR resource and ACK / NACK resource, or Uplink control information (that is, response signal, SR, or both SR and response signal) is transmitted using a total of two resources of one SR resource and one ACK / NACK resource.

The base station 100 is provided with a processing system of a despreading unit 115 and a correlation processing unit 117 that perform processing on each of the extracted resources. Specifically, the despreading units 115-1 to 115-n and the correlation processing units 117-1 to 11-n are respectively associated with any of the resources (SR resource and ACK / NACK resource).

Specifically, the despreading unit 115 uses a Walsh sequence (a code used for secondary spreading of the data portion) and a DFT sequence (a code used for spreading the reference signal portion) corresponding to each resource, and The signal received via these resources is despread, and the despread signal is output to the correlation processing unit 117.

Sequence control section 116 generates a ZAC sequence corresponding to each of the data part and reference signal part of the SR resource or ACK / NACK resource transmitted from terminal 200. In addition, sequence control section 116 specifies a correlation window from which a signal is to be extracted in association with these resources. Then, sequence control unit 116 outputs information indicating the identified correlation window and the generated ZAC sequence to correlation processing unit 117.

The correlation processing unit 117 uses the information indicating the correlation window input from the sequence control unit 116 and the ZAC sequence to obtain the correlation value between the despread signal and the ZAC sequence in the data portion (ie, as shown in FIG. 1). S ₀ to S ₃ ) and the reference signal portion (that is, R ₀ to R ₂ shown in FIG. 1) are obtained separately. Then, the correlation processing unit 117 outputs information regarding the obtained correlation value to the determination unit 118.

The determination unit 118 determines whether the SR and the response signal are transmitted from the terminal based on the correlation value input from the correlation processing unit 117. That is, the determination unit 118 includes two ACK / NACK resources, one ACK / NACK resource, two SR resources, one SR resource, or one SR resource and one ACK / NACK resource. Which of these is used by the terminal 200 is determined. Details of the SR and response signal determination processing in the determination unit 118 of the base station 100 will be described later.

Further, when determining that the terminal 200 is transmitting SR, the determining unit 118 outputs information on the SR to an uplink resource allocation control unit (not shown). When determining that the terminal 200 is transmitting a response signal, the determining unit 118 further determines, for example, by synchronous detection whether the response signal indicates ACK or NACK. Then, determination section 118 outputs a determination result (ACK or NACK) for each terminal to retransmission control signal generation section 119. In addition, when determining that terminal 200 has not transmitted a response signal, determining section 118 outputs DTX information to retransmission control signal generating section 119.

Further, when the uplink resource allocation control unit (not shown) receives the SR, the base station 100 transmits the uplink allocation control information for reporting the uplink data allocation resource to the terminal so that the terminal 200 can transmit the uplink data. 200. In this way, base station 100 determines whether it is necessary to allocate resources for uplink data to terminal 200 based on the uplink control channel. Details of operations in the uplink resource allocation control unit and details of resource allocation operations for uplink data for terminal 200 in base station 100 are omitted.

Whether retransmission control signal generation section 119 should retransmit the data (downlink data) transmitted in the downlink unit band based on the determination result (ACK or NACK) or the DTX information related to the response signal input from determination section 118 And a retransmission control signal is generated based on the determination result. Specifically, when receiving a response signal indicating DACK or DTX, retransmission control signal generation section 119 generates a retransmission control signal indicating a retransmission command and outputs the retransmission control signal to data transmission control section 106. . When receiving a response signal indicating ACK, retransmission control signal generation section 119 generates a retransmission control signal indicating that retransmission is not performed, and outputs the retransmission control signal to data transmission control section 106.

[Terminal configuration]
FIG. 5 is a block diagram showing a configuration of terminal 200 according to the present embodiment. In FIG. 5, a terminal 200 includes a radio reception unit 201, a CP removal unit 202, an FFT unit 203, an extraction unit 204, a demodulation unit 205, a decoding unit 206, a determination unit 207, a control unit 208, It has a demodulation unit 209, a decoding unit 210, a CRC unit 211, a response signal generation unit 212, an uplink control channel signal generation unit 213, and a radio transmission unit 214. 5 has two antennas 1 and 2. The terminal 200 shown in FIG.

The radio reception unit 201 receives the OFDM signal transmitted from the base station 100 via the antennas 1 and 2 and performs reception processing such as down-conversion and A / D conversion on the received OFDM signal. The received OFDM signal includes a PDSCH signal (downlink data) assigned to a resource in PDSCH or a PDCCH signal (downlink assignment control information) assigned to a resource in PDCCH.

CP removing section 202 removes the CP added to the OFDM signal after reception processing.

The FFT unit 203 performs FFT on the received OFDM signal and converts it into a frequency domain signal, and outputs the obtained received signal to the extracting unit 204.

The extraction unit 204 extracts a downlink control channel signal (PDCCH signal) from the received signal received from the FFT unit 203 according to the input coding rate information. That is, since the number of CCEs constituting the downlink control information allocation resource changes according to the coding rate, the extraction unit 204 extracts the downlink control channel signal using the number of CCEs corresponding to the coding rate as an extraction unit. . The extracted downlink control channel signal is output to demodulation section 205.

Further, the extraction unit 204 extracts downlink data (downlink data channel signal (PDSCH signal)) from the received signal based on the information on the downlink data allocation resource addressed to the own device received from the determination unit 207, and sends it to the demodulation unit 209. Output.

The demodulation unit 205 demodulates the downlink control channel signal received from the extraction unit 204 and outputs the obtained demodulation result to the decoding unit 206.

The decoding unit 206 decodes the demodulation result received from the demodulation unit 205 according to the input coding rate information, and outputs the obtained decoding result to the determination unit 207.

The determination unit 207 blindly determines whether or not the control information included in the decoding result received from the decoding unit 206 is control information addressed to the own device. This determination is performed in units of decoding results corresponding to the above extraction units. For example, the determination unit 207 demasks the CRC bits with the terminal ID of the own device, and determines that the control information with CRC = OK (no error) is the control information addressed to the own device. Then, the determination unit 207 outputs information related to downlink data allocation resources for the own device included in the control information addressed to the own device to the extraction unit 204.

Also, the determination unit 207 identifies the CCE to which the control information addressed to itself is mapped, and outputs the identified CCE identification information to the control unit 208.

The control unit 208 identifies the PUCCH resource (frequency / code) corresponding to the CCE indicated by the CCE identification information received from the determination unit 207 as an ACK / NACK resource. Then, the control unit 208 transmits the ZAC sequence and the cyclic shift amount respectively corresponding to the identified ACK / NACK resource and the SR resource previously notified from the base station 100 to the spreading unit 222 of the uplink control channel signal generation unit 213. And output the frequency resource information to the IFFT unit 223. In addition, control section 208 outputs a ZAC sequence and frequency resource information as a reference signal corresponding to each resource to IFFT section 226, and outputs a Walsh sequence corresponding to an ACK / NACK resource and an SR resource to spreading section 225. The DFT sequence corresponding to the reference signal is output to spreading section 228.

Also, when there is no response signal to be transmitted in the subframe that has received the SR (that is, when no downlink allocation control information is detected), the control unit 208 notifies the response signal generation unit 212 of “NACK Is output to the uplink control channel signal generation unit 213. As described above, the control unit 208 controls the transmission of the response signal or SR based on the response signal and the generation status of the SR. Details of SR and response signal transmission control in control unit 208 will be described later.

Demodulation section 209 demodulates the downlink data received from extraction section 204, and outputs the demodulated downlink data to decoding section 210.

Decoding section 210 decodes the downlink data received from demodulation section 209 and outputs the decoded downlink data to CRC section 211.

The CRC unit 211 generates the decoded downlink data received from the decoding unit 210, detects an error using the CRC, and when CRC = OK (no error), ACK and CRC = NG (error) In this case, NACK is output to the response signal generation unit 212. Also, CRC section 211 outputs the decoded downlink data as received data when CRC = OK (no error).

The response signal generation unit 212 generates a response signal to be transmitted to the base station 100 based on the downlink data reception status (downlink data error detection result) input from the CRC unit 211. However, the response signal generation unit 212 generates a NACK when there is an instruction from the control unit 208 (that is, when the terminal 200 transmits only SR). Then, the response signal generation unit 212 outputs the generated “response signal or NACK” (hereinafter simply referred to as “response signal”) to the uplink control channel signal generation units 213-1 and 213-2.

The uplink control channel signal generation unit 213 generates an uplink control channel signal (PUCCH signal) based on the response signal received from the response signal generation unit 212. Terminal 200 is provided with uplink control channel signal generation sections 213-1 and 213-2 corresponding to antenna 1 and antenna 2 of terminal 200, respectively. Also, uplink control channel signal generation sections 213-1 and 213-2 correspond to either SR resource or ACK / NACK resource in PUCCH.

Specifically, the uplink control channel signal generation unit 213 includes a modulation unit 221, a spreading unit 222, an IFFT unit 223, a CP adding unit 224, a spreading unit 225, an IFFT unit 226, and a CP adding unit 227. , A diffusion unit 228 and a multiplexing unit 229.

The modulation unit 221 modulates the response signal input from the response signal generation unit 212 and outputs it to the spreading unit 222.

The spreading unit 222 performs first spreading of the response signal based on the ZAC sequence and the cyclic shift amount set by the control unit 208, and outputs the response signal after the first spreading to the IFFT unit 223. That is, spreading section 222 performs first spreading of the response signal in accordance with an instruction from control section 208.

The IFFT unit 223 arranges the response signal after the first spreading on the frequency axis based on the frequency resource information input from the control unit 208, and performs IFFT. Then, IFFT section 223 outputs the response signal after IFFT to CP adding section 224.

The CP adding unit 224 adds the same signal as the tail part of the response signal after IFFT to the head of the response signal as a CP.

Spreading section 225 uses the Walsh sequence set by control section 208 to secondarily spread the response signal after CP addition, and outputs the response signal after the second spreading to multiplexing section 229. That is, spreading section 225 performs second spreading on the response signal after the first spreading using a Walsh sequence corresponding to the resource selected by control section 208.

The IFFT unit 226 arranges the reference signal on the frequency axis based on the frequency resource information input from the control unit 208, and performs IFFT. Then, IFFT unit 226 outputs the reference signal after IFFT to CP adding unit 227.

The CP adding unit 227 adds the same signal as the tail part of the reference signal after IFFT to the head of the reference signal as a CP.

Spreading section 228 spreads the reference signal after adding the CP with the DFT sequence instructed from control section 208 and outputs the spread reference signal to multiplexing section 229.

The multiplexing unit 229 time-multiplexes the response signal after second spreading and the reference signal after spreading into one slot, and outputs the result to the radio transmitting unit 214 corresponding to each of the antennas 1 and 2.

The radio transmission unit 214 performs transmission processing such as D / A conversion, amplification, and up-conversion on the signal received from the multiplexing unit 229 of the uplink control channel signal generation unit 213, and transmits the signal from the antenna to the base station 100. Terminal 200 is provided with radio transmission sections 214-1 and 214-2 corresponding to antenna 1 and antenna 2 of terminal 200, respectively, and radio transmission sections 214-1 and 214-2 are SR resources or A response signal or SR is transmitted using any one of the ACK / NACK resources.

Next, the operation of the terminal 200 will be described. In the following description, the terminal 200 includes two antennas. Also, terminal 200 allocates SR resources (or ACK / NACK resources) one by one to two antennas, and transmits the same signal from the two antennas. That is, in terminal 200, SORTD is applied to one or both of SR and the response signal.

That is, in the following description, in the LTE-A system, it is assumed that two resources are configured in the same subframe with one or both of the SR resource and the ACK / NACK resource. Then, terminal 200 assigns either one of the response signal or SR to the code resource (SR resource or ACK / NACK resource), and a plurality of (here, two) response signals or SRs assigned to the code resource. Transmit from each antenna.

Here, as shown in FIG. 6A, a case where two SR resources (first SR resource and second SR resource) are set in advance for terminal 200 and there are two ACK / NACK resources. Assume that “state 1” (FIG. 7A). Also, as shown in FIG. 6A, a case where two SR resources are set in advance for terminal 200 and there is one ACK / NACK resource is referred to as “state 2” (FIG. 8A). Furthermore, as shown in FIG. 6B, a case where one SR resource is preset for terminal 200 and there are two ACK / NACK resources is referred to as “state 3” (FIG. 9A). Hereinafter, the operation of terminal 200 in the three cases of “state 1” to “state 3” will be described in detail.

<State 1: When two SR resources are preset for terminal 200 and there are two ACK / NACK resources (FIGS. 6A and 7A to 7D)>
In the following description, as shown in FIG. 6A, the base station 100 provides information on two SR resources to the terminal 200 in the uplink unit band (uplink unit band set for the terminal 200) shown in FIG. Is notified in advance. Further, it is assumed that the number of CCEs occupied by the L1 / L2 CCH received by the terminal 200 is two or more. That is, as illustrated in FIG. 7A, the control unit 208 of the terminal 200 is associated with the information regarding the two SR resources notified from the base station 100 and the CCE occupied by the L1 / L2 CCH received by the own device. Information about two ACK / NACK resources.

When L1 / L2CCH occupies N (N> 2) CCEs, terminal 200 selects two ACK / NACK resources associated with two CCEs according to a preset rule. To do.

Here, in the uplink unit band PUCCH shown in FIG. 7A, two SR resources (first SR resource and second SR resource) and two ACK / NACK resources (first ACK / NACK resource and second SR resource). ACK / NACK resources) are different code resources in which at least one of a ZAC sequence (first spreading) or an orthogonal code sequence is different.

Hereinafter, in the PUCCH of the uplink unit band shown in FIG. 7A, it corresponds to the SR occurrence status in a certain subframe and the response signal occurrence status (that is, the detection status of downlink allocation control information in terminal 200). The detailed operation of the transmission control process in terminal 200 (control unit 208) will be described with reference to FIGS. 7B to 7D.

<State 1: When both SR and response signal occur simultaneously in terminal 200 (FIG. 7B)>
In this case, in terminal 200, control section 208 transmits information corresponding to the second SR resource (cyclic shift amount, ZAC sequence, frequency resource information, Walsh sequence, DFT sequence) to uplink control channel signal generation section 213-1. ) Is output. Further, control section 208 outputs information (cyclic shift amount, ZAC sequence, frequency resource information, Walsh sequence, DFT sequence) corresponding to the first ACK / NACK resource to uplink control channel signal generation section 213-2. To do.

Further, the control unit 208 instructs the response signal generation unit 212 to output the response signal input from the CRC unit 211 to the uplink control channel signal generation units 213-1 and 213-2.

That is, when both the SR and the response signal are generated simultaneously in a certain subframe, the terminal 200, as shown in FIG. 7B, the second SR resource and the first ACK / NACK resource (that is, SR A response signal ("A / N") for downlink data is transmitted using both resources and ACK / NACK resources). Specifically, terminal 200 transmits the same response signal from antenna 1 using the second SR resource, and transmits from antenna 2 using the first ACK / NACK resource. That is, terminal 200 transmits the same response signals respectively assigned to the second SR resource and the first ACK / NACK resource, which are different code resources, from two antennas 1 and 2, respectively.

Then, the determination unit 118 of the base station 100 uses the second SR resource and the first ACK / NACK resource in the uplink unit band PUCCH shown in FIG. Is determined to have been transmitted. Furthermore, the base station 100 determines that the terminal 200 receives ACK or NACK as a response signal based on the phase of the signal received by the second SR resource and the first ACK / NACK resource (that is, based on the demodulation result by BPSK). Which of these is transmitted is determined.

<State 1: When only a response signal is generated in terminal 200 (FIG. 7C)>
In this case, in terminal 200, control section 208 provides information (cyclic shift amount, ZAC sequence, frequency resource information, Walsh sequence, etc.) corresponding to the first ACK / NACK resource to uplink control channel signal generation section 213-1. DFT sequence) is output. Control section 208 also outputs information (cyclic shift amount, ZAC sequence, frequency resource information, Walsh sequence, DFT sequence) corresponding to the second ACK / NACK resource to uplink control channel signal generation section 213-2. To do.

That is, when only a response signal is generated in a certain subframe, terminal 200 receives the first ACK / NACK resource and the second ACK / NACK resource (that is, ACK / NACK) as shown in FIG. 7C. A response signal ("A / N") for downlink data is transmitted using (resource only). Specifically, terminal 200 transmits the same response signal from antenna 1 using the first ACK / NACK resource and transmits from antenna 2 using the second ACK / NACK resource. That is, terminal 200 transmits the same response signal allocated to the first and second ACK / NACK resources, which are different code resources, from two antennas 1 and 2, respectively.

Then, the determination unit 118 of the base station 100 uses the first ACK / NACK resource and the second ACK / NACK resource in the uplink unit band PUCCH shown in FIG. Is determined to have been transmitted. Also, base station 100 determines that terminal 200 has transmitted ACK or NACK as a response signal based on the phase of the response signal received using the first and second ACK / NACK resources.

<State 1: When SR only occurs in terminal 200 (FIG. 7D)>
In this case, in terminal 200, control section 208 provides information (cyclic shift amount, ZAC sequence, frequency resource information, Walsh sequence, DFT sequence) corresponding to the first SR resource to uplink control channel signal generation section 213-1. ) Is output. Control section 208 also outputs information (cyclic shift amount, ZAC sequence, frequency resource information, Walsh sequence, DFT sequence) corresponding to the second SR resource to uplink control channel signal generation section 213-2.

Further, the control unit 208 instructs the response signal generation unit 212 to output “NACK” to the uplink control channel signal generation units 213-1 and 213-2.

That is, when only SR occurs in a certain subframe, terminal 200 uses the first SR resource and the second SR resource (that is, only SR resource) as shown in FIG. An SR having the same phase point as “NACK” is transmitted. That is, terminal 200 transmits a NACK using the first and second SR resources shown in FIG. 7D. Specifically, terminal 200 transmits the same SR (NACK) from antenna 1 using the first SR resource and transmits from antenna 2 using the second SR resource. That is, terminal 200 transmits the same SR (NACK) respectively assigned to the first and second SR resources, which are different code resources, using two antennas 1 and 2, respectively.

Here, the operation of terminal 200 shown in FIG. 7D (that is, the operation in which terminal 200 transmits only SR) is when only SR occurs in terminal 200 when downlink data is not assigned to terminal 200. Two situations are assumed when SR occurs when terminal 200 fails to receive downlink allocation control information for the terminal 200. However, since base station 100 knows whether downlink data has been allocated to terminal 200, these two situations can be distinguished.

<State 1: When neither SR nor a response signal is generated in terminal 200 (not shown)>
In this case, terminal 200 does not transmit the SR and response signal in the PUCCH resource.

As described above, when there are two SR resources and ACK / NACK resources that can be used by terminal 200 (state 1), transmission control in terminal 200 (control unit 208) according to the SR generation status and the response signal generation status The detailed operation of the processing has been described.

As a result, terminal 200 has successfully received downlink allocation control information, but has detected CRC = NG for downlink data and SR has occurred simultaneously (ie, a state of (SR + NACK) (FIG. 7B)). Thus, the base station 100 can distinguish the state in which the terminal 200 has failed to receive downlink allocation control information and SR has occurred simultaneously (that is, the state of (SR + DTX) (FIG. 7D)).

More specifically, in the LTE system described above, in FIG. 3A (during SR + NACK transmission) and FIG. 3C (during SR + DTX transmission), signals are transmitted at the same phase point (NACK) using the same resource (SR resource). Therefore, (SR + NACK) and (SR + DTX) cannot be distinguished on the base station side. On the other hand, in the LTE-A system according to the present embodiment, signals are transmitted using different resources in FIG. 7B (when SR + NACK is transmitted) and FIG. 7D (when SR + DTX is transmitted). On the side, (SR + NACK) and (SR + DTX) can be distinguished.

That is, in FIG. 7B (at the time of SR + NACK transmission), base station 100 determines that SR and NACK are transmitted from terminal 200 because signals are allocated to SR resources and ACK / NACK resources, and terminal 200 is It is determined that the allocation control information has been successfully received. On the other hand, in FIG. 7D (during SR + DTX transmission), base station 100 determines that only SR (that is, SR + DTX) has been transmitted from terminal 200 because a signal is allocated only to SR resources, and terminal 200 allocates downlink allocation. It is determined that reception of control information has failed.

Thus, since base station 100 can determine whether terminal 200 has received downlink allocation control information or not, retransmission control of downlink data (for example, IR, for example) depends on whether terminal 200 has received downlink allocation control information. Etc.) can be performed efficiently. That is, it is possible to improve the efficiency of retransmission control (retransmission efficiency) of downlink data.

<State 2: When two SR resources are preset for terminal 200 and there is one ACK / NACK resource (FIGS. 6A and 8A to 8D)>
In the following description, as shown in FIG. 6A, the base station 100 provides information on two SR resources to the terminal 200 in the uplink unit band (uplink unit band set for the terminal 200) shown in FIG. Is notified in advance. Further, it is assumed that the L1 / L2CCH received by the terminal 200 has only one CCE. That is, as illustrated in FIG. 8A, the control unit 208 of the terminal 200 is associated with the information regarding the two SR resources notified from the base station 100 and the CCE occupied by the L1 / L2 CCH received by the own device. It holds information about a single ACK / NACK resource.

Here, in the uplink unit band PUCCH shown in FIG. 8A, two SR resources (first SR resource and second SR resource) and one ACK / NACK resource are ZAC sequences (first spreading) or orthogonal codes. The code resources are different from each other in which at least one of the sequences is different.

Hereinafter, in the PUCCH of the uplink unit band shown in FIG. 8A, depending on the occurrence status of the SR in a certain subframe and the occurrence status of the response signal (that is, the detection status of the downlink allocation control information in the terminal 200) The detailed operation of the transmission control process in terminal 200 (control unit 208) will be described using FIGS. 8B to 8D.

<State 2: When both SR and response signal occur simultaneously in terminal 200 (FIG. 8B)>
In this case, in terminal 200, control section 208 transmits information corresponding to the second SR resource (cyclic shift amount, ZAC sequence, frequency resource information, Walsh sequence, DFT sequence) to uplink control channel signal generation section 213-1. ) Is output. Control section 208 also outputs information (cyclic shift amount, ZAC sequence, frequency resource information, Walsh sequence, DFT sequence) corresponding to the ACK / NACK resource to uplink control channel signal generation section 213-2.

That is, when both the SR and the response signal are generated at the same time in a certain subframe, the terminal 200, as shown in FIG. 8B, performs the second SR resource and the same as in the state 1 (FIG. 7B). A response signal ("A / N") for downlink data is transmitted using ACK / NACK resources (that is, both SR resources and ACK / NACK resources).

Then, the determination unit 118 of the base station 100 transmits the SR and the response signal because the second SR resource and the ACK / NACK resource are used in the uplink unit band PUCCH illustrated in FIG. 8B. Is determined. Furthermore, based on the phase of the signal received by the second SR resource and the ACK / NACK resource (that is, based on the demodulation result by BPSK), the base station 100 receives either ACK or NACK as a response signal. Determine if it has been sent.

<State 2: When only a response signal is generated in terminal 200 (FIG. 8C)>
In this case, in terminal 200, control section 208 transmits information corresponding to ACK / NACK resources (cyclic shift amount, ZAC sequence, frequency resource information, Walsh sequence) to uplink control channel signal generation sections 213-1 and 213-2. , DFT sequence).

That is, when only a response signal is generated within a certain subframe, terminal 200 uses only one ACK / NACK resource with both two antennas as shown in FIG. A response signal (“A / N”) is transmitted. Specifically, terminal 200 transmits the same response signal from antenna 1 and antenna 2 using the same ACK / NACK resource.

Then, the determination unit 118 of the base station 100 determines that the terminal 200 has transmitted a response signal because only one ACK / NACK resource is used in the PUCCH of the uplink unit band shown in FIG. 8C. Further, base station 100 determines that terminal 200 has transmitted ACK or NACK as a response signal based on the phase of the response signal received using the ACK / NACK resource.

<State 2: When SR only occurs in terminal 200 (FIG. 8D)>
In this case, in terminal 200, control section 208 provides information (cyclic shift amount, ZAC sequence, frequency resource information, Walsh sequence, DFT sequence) corresponding to the first SR resource to uplink control channel signal generation section 213-1. ) Is output. Control section 208 also outputs information (cyclic shift amount, ZAC sequence, frequency resource information, Walsh sequence, DFT sequence) corresponding to the second SR resource to uplink control channel signal generation section 213-2.

That is, when only SR occurs in a certain subframe, terminal 200 performs the first SR resource and the second SR resource as in state 1 (FIG. 7D) as shown in FIG. 8D. (That is, only SR resource) is used to transmit an SR having the same phase point as “NACK”. That is, terminal 200 transmits a NACK using the first and second SR resources shown in FIG. 8D.

Here, the operation of terminal 200 shown in FIG. 8D (that is, the operation in which terminal 200 transmits only SR) is the case where only SR occurs in terminal 200 when downlink data is not assigned to terminal 200. Two situations are assumed when SR occurs when terminal 200 fails to receive downlink allocation control information for the terminal 200. However, since base station 100 knows whether downlink data has been allocated to terminal 200, these two situations can be distinguished.

<State 2: When neither SR nor a response signal is generated in terminal 200 (not shown)>
In this case, terminal 200 does not transmit the SR and response signal in the PUCCH resource.

As described above, when there are two SR resources that can be used by terminal 200 and one ACK / NACK resource (state 2), terminal 200 (control unit 208) according to the SR generation status and the response signal generation status. The detailed operation of the transmission control process in FIG.

As a result, as in the state 1 (FIGS. 7A to 7D), the terminal 200 has successfully received the downlink allocation control information, but has detected CRC = NG with respect to the downlink data and the SR has occurred simultaneously (ie, The state of (SR + NACK) (FIG. 8B)) and the state in which terminal 200 has failed to receive downlink allocation control information and SR has occurred simultaneously (that is, the state of (SR + DTX) (FIG. 8D)). Can be distinguished on the side. That is, since the base station 100 can determine whether or not the terminal 200 has received downlink allocation control information, the base station 100 performs downlink data retransmission control (for example, IR or the like) according to whether or not the terminal 200 has received downlink allocation control information. It can be done efficiently. Therefore, it is possible to improve the efficiency of retransmission control (retransmission efficiency) of downlink data.

<State 3: When one SR resource is set in advance for terminal 200 and there are two ACK / NACK resources (FIGS. 6B and 9A to 9D)>
In the following description, as illustrated in FIG. 6B, the base station 100 provides information on one SR resource to the terminal 200 in the uplink unit band (uplink unit band set for the terminal 200) illustrated in FIG. Is notified in advance. Further, it is assumed that the number of CCEs occupied by the L1 / L2 CCH received by the terminal 200 is two or more. That is, as illustrated in FIG. 9A, the control unit 208 of the terminal 200 is associated with information on one SR resource notified from the base station 100 and the CCE occupied by the L1 / L2 CCH received by the own device. Information about two ACK / NACK resources.

Here, in the uplink unit band PUCCH shown in FIG. 9A, one SR resource and two ACK / NACK resources (first ACK / NACK resource and second ACK / NACK resource) are ZAC sequences (first spreading). ) Or different code resources in which at least one of the orthogonal code sequences is different.

Hereinafter, in the PUCCH of the uplink unit band shown in FIG. 9A, it corresponds to the SR occurrence status in a certain subframe and the response signal occurrence status (that is, the detection status of downlink allocation control information in terminal 200). The detailed operation of the transmission control process in terminal 200 (control unit 208) will be described with reference to FIGS. 9B to 9D.

<State 3: When both SR and response signal occur simultaneously in terminal 200 (FIG. 9B)>
In this case, in terminal 200, control section 208 outputs information (cyclic shift amount, ZAC sequence, frequency resource information, Walsh sequence, DFT sequence) corresponding to the SR resource to uplink control channel signal generation section 213-1. To do. In addition, control section 208 outputs information (cyclic shift amount, ZAC sequence, frequency resource information, Walsh sequence, DFT sequence) corresponding to the first ACK / NACK resource to uplink control channel signal generation section 213-2. To do.

That is, if both the SR and the response signal are generated at the same time in a certain subframe, terminal 200 performs the same as in state 1 (FIG. 7B) or state 2 (FIG. 8B) as shown in FIG. 9B. , A response signal (“A / N”) for downlink data is transmitted using the SR resource and the first ACK / NACK resource (that is, both the SR resource and the ACK / NACK resource). Specifically, terminal 200 transmits the same response signal from antenna 1 using the SR resource and transmits from antenna 2 using the first ACK / NACK resource.

Then, the determination unit 118 of the base station 100 transmits the SR and the response signal because the SR resource and the first ACK / NACK resource are used in the uplink unit band PUCCH illustrated in FIG. 9B. Is determined. Furthermore, based on the phase of the signal received using the SR resource and the first ACK / NACK resource (that is, based on the result of demodulation by BPSK), base station 100 determines whether ACK or NACK is received by terminal 200 as a response signal. Determine if it has been sent.

<State 3: When only a response signal is generated in terminal 200 (FIG. 9C)>
In this case, in terminal 200, control section 208 provides information (cyclic shift amount, ZAC sequence, frequency resource information, Walsh sequence, etc.) corresponding to the first ACK / NACK resource to uplink control channel signal generation section 213-1. DFT sequence) is output. Control section 208 also outputs information (cyclic shift amount, ZAC sequence, frequency resource information, Walsh sequence, DFT sequence) corresponding to the second ACK / NACK resource to uplink control channel signal generation section 213-2. To do.

That is, when only a response signal is generated in a certain subframe, terminal 200, as shown in FIG. 9C, similarly to state 1 (FIG. 7C), first ACK / NACK resource and second ACK A response signal ("A / N") for downlink data is transmitted using the / NACK resource. Specifically, terminal 200 transmits the same response signal from antenna 1 using the first ACK / NACK resource and transmits from antenna 2 using the second ACK / NACK resource.

<State 3: When SR only occurs in terminal 200 (FIG. 9D)>
In this case, in terminal 200, control section 208 transmits information corresponding to the SR resource (cyclic shift amount, ZAC sequence, frequency resource information, Walsh sequence, DFT) to uplink control channel signal generation sections 213-1 and 213-2. Output).

That is, when only SR occurs in a certain subframe, terminal 200 uses only SR resources as in state 1 (FIG. 7D) or state 2 (FIG. 8D) as shown in FIG. 9D. And transmit SR which is the same phase point as “NACK”. That is, terminal 200 transmits a NACK using the first and second SR resources shown in FIG. 9D. Specifically, terminal 200 transmits the same SR (NACK) from antenna 1 and antenna 2 using the same SR resource.

Here, the operation of terminal 200 shown in FIG. 9D (that is, the operation in which terminal 200 transmits only SR) is the case where only SR occurs in terminal 200 when downlink data is not assigned to terminal 200. Two situations are assumed when SR occurs when terminal 200 fails to receive downlink allocation control information for the terminal 200. However, since base station 100 knows whether downlink data has been allocated to terminal 200, these two situations can be distinguished.

<State 3: When neither SR nor a response signal is generated in terminal 200 (not shown)>
In this case, terminal 200 does not transmit the SR and response signal in the PUCCH resource.

As described above, when there is one SR resource that can be used by terminal 200 and there are two ACK / NACK resources (state 3), terminal 200 (control unit 208) corresponding to the SR generation status and the response signal generation status. The detailed operation of the transmission control process in FIG.

As a result, as in the state 1 (FIGS. 7A to 7D) and the state 2 (FIGS. 8A to D), the terminal 200 succeeds in receiving the downlink allocation control information, but detects CRC = NG for the downlink data, and A state in which SR occurs simultaneously (that is, a state of (SR + NACK) (FIG. 9B)), a state in which terminal 200 has failed to receive downlink allocation control information, and a state in which SR occurs simultaneously (that is, a state of (SR + DTX) ( 9D)) can be distinguished from the base station 100 side. That is, since the base station 100 can determine whether or not the terminal 200 has received downlink allocation control information, the base station 100 performs downlink data retransmission control (for example, IR or the like) according to whether or not the terminal 200 has received downlink allocation control information. It can be done efficiently. Therefore, it is possible to improve the efficiency of retransmission control (retransmission efficiency) of downlink data.

The state 1 to state 3 have been described above.

In this way, when only SR occurs in a certain subframe (FIG. 7D, FIG. 8D, or FIG. 9D), control unit 208 of terminal 200 transmits SR using only “SR resource”. To control. In addition, when only a response signal is generated in a certain subframe (FIG. 7C, FIG. 8C, or FIG. 9C), the control unit 208 transmits the response signal using only “ACK / NACK resource”. Control.

In addition, when the SR and the response signal are simultaneously generated in a certain subframe (FIG. 7B, FIG. 8B, or FIG. 9B), the control unit 208 is configured when only SR is generated in a certain subframe (FIG. 7). 7D, FIG. 8D, or FIG. 9D) when at least one of the “SR resources” to which SR is assigned (herein, the second SR resource) and only a response signal is generated in a certain subframe ( The response signal is transmitted using at least one of the “ACK / NACK resources” (here, the first ACK / NACK resource) to which the response signal is allocated in FIG. 7C, FIG. 8C, or FIG. 9C. Control to do.

In other words, when the SR and the response signal are simultaneously generated in a certain subframe, the terminal 200, as shown in FIG. 7B, FIG. 8B, or FIG. 9B, part of the response signal transmitted from the terminal 200. Are transmitted using the SR resource instead of the ACK / NACK resource (for example, the second ACK / NACK resource in FIG. 7B).

That is, terminal 200 transmits a signal (SR or response signal) to be transmitted in a certain subframe using a resource including a code resource corresponding to the signal. Specifically, when transmitting SR within a certain subframe, terminal 200 uses “SR resource” that is a resource to be used for transmission of SR. In addition, when transmitting a response signal within a certain subframe, terminal 200 uses “ACK / NACK resource” that is a resource to be used for transmitting the response signal. Therefore, terminal 200 uses both “SR resource” and “ACK / NACK resource” when transmitting SR and response signal simultaneously in a certain subframe.

Thereby, base station 100 determines which code resource (only SR resource, only ACK / NACK resource, or both SR resource and ACK / NACK resource) is transmitted using signal from terminal 200. Thus, the content of the signal (SR only (or SR + DTX), response signal only, or both SR and response signal) can be specified. That is, in base station 100 and terminal 200, in the resources (SR resource and ACK / NACK resource) that terminal 200 can use in a certain subframe, the generation status of SR and response signals and the resources used in that status Are associated with each other. For example, the situation shown in FIG. 7B in which the SR and the response signal are generated simultaneously is associated with the second SR resource and the first ACK / NACK resource as resources used in the situation. Therefore, the base station 100 can grasp the signal generation status at the terminal 200 by determining the code resource used for signal transmission from the terminal 200.

In this way, the base station 100 can receive a signal by distinguishing between the (SR + NACK) state and the (SR + DTX) state. That is, the base station 100 can determine whether or not reception of downlink allocation control information on the terminal 200 side is successful. Thereby, base station 100 can efficiently perform downlink data retransmission control (such as IR) in accordance with the success or failure of downlink allocation control information reception on terminal 200 side.

Thus, according to the present embodiment, in the LTE-A system, a subframe in which a base station should receive a response signal from a terminal (that is, a response signal if the terminal has correctly received downlink allocation control information). Even if SR occurs on the terminal side, the base station can determine whether or not reception of downlink allocation control information on the terminal side is successful, and retransmission efficiency can be improved.

(Embodiment 2)
As one of the determination methods for determining which code resource is used by the terminal on the base station side, there is a determination method (likelihood determination) based on the likelihood after synchronous detection. Specifically, the base station first performs synchronous detection on signals allocated to different code resources (for example, SR resource and ACK / NACK resource in Embodiment 1), respectively. Next, the base station combines each signal with a set of code resources that can be used by the terminal using, for example, maximum ratio combining (also referred to as MRC: Maximum Ratio Combining).

Then, the base station calculates a likelihood indicating how close the combined result of each set is to the signal point of the response signal. For example, in the first embodiment, in the state 1 (FIG. 7A) in which the number of SR resources and ACK / NACK resources that each terminal can use is two, the base station and the terminal 200 both receive SR and response signals at the same time A case will be described in which a case where the error occurs (FIG. 7B) and a case where only SR occurs in the terminal 200 (FIG. 7D) are discriminated.

In this case, as shown in FIG. 10, the base station obtains the Euclidean distance between the combination result of each set and the signal point of the response signal that is closest (in FIG. 10, the phase point (1, 0)), and the reciprocal of the Euclidean distance. Is calculated as a likelihood. Then, the base station determines that the code resource of the group with the higher likelihood (that is, the group with the shorter Euclidean distance) is the code resource used by the terminal. In FIG. 10, a set of the first ACK / NACK resource and the second SR resource (when SR + response signal is transmitted (FIG. 7B)) is a set of the first SR resource and the second SR resource (only SR). Likelihood is larger than when transmitting (FIG. 7D) (Euclidean distance is short). Therefore, in FIG. 10, the base station determines that the set of the first ACK / NACK resource and the second SR resource is used by the terminal.

Hereinafter, the likelihood determination in the base station will be described in more detail. Here, in the terminal, as signal point arrangement (constellation) of signals (SR or response signals) respectively assigned to different code resources (SR resource and ACK / NACK resource shown in FIG. 7A), for example, As shown in FIG. 10, ACK is associated with the phase point (−1, 0), and NACK is associated with the phase point (1, 0).

Hereinafter, a case where both SR and a response signal are simultaneously generated in a certain subframe (FIG. 7B) will be described as an example. A case where the response signal is NACK will be described. Therefore, as shown in FIG. 7B, when both SR and response signals occur simultaneously in a certain subframe, the second SR resource among the SR resources and the ACK / NACK, as in the first embodiment. Of the resources, the first ACK / NACK resource is used. That is, in the terminal, as shown in FIG. 10, NACK (phase point (1, 0)) is allocated to the first ACK / NACK resource and the second SR resource.

Therefore, in the base station, as shown in FIGS. 11A and 11B, in the first ACK / NACK resource and the second SR resource, the signal component (white circle shown in FIG. 11) is the NACK phase point (1, 0). Appears near (black circle shown in FIG. 11). Note that although nothing is assigned to the first SR resource in the terminal, a noise component appears in the first SR resource in the base station as shown in FIG. 11B. In general, the noise component appears at a position away from the NACK phase point (1, 0) (black circle shown in FIG. 11).

Then, as shown in FIG. 11A, the base station first assigns the signal component assigned to the first ACK / NACK resource (near the phase point (1, 0) in FIG. 11A) and the second SR resource. The obtained signal components (in the vicinity of phase point (1, 0) in FIG. 11A) are synthesized. As a result, as shown in FIG. 11A, a signal near the phase point (1, 0) is obtained as a synthesis result. Similarly, the base station, as shown in FIG. 11B, the noise component present in the first SR resource and the signal component assigned to the second SR resource (in the vicinity of the phase point (1, 0) in FIG. 11B). ) And. As a result, as shown in FIG. 11B, a signal slightly separated from the phase point (1, 0) is obtained as a synthesis result.

Then, the base station is closest to the likelihood calculated using the Euclidean distance between the combined result shown in FIG. 11A and the closest NACK (phase point (1, 0)) and the combined result shown in FIG. 11B. The likelihood calculated using the Euclidean distance to NACK (phase point (1, 0)) is compared. However, as described above, the noise component is likely to appear at a position distant from the NACK phase point (1, 0) (black circle shown in FIG. 11). Therefore, as shown in FIG. 11A and FIG. The Euclidean distance between the synthesis result shown in FIG. 11B and the NACK phase point is likely to be longer than the Euclidean distance between the synthesis result shown in FIG. 11A and the NACK phase point.

Therefore, the base station is more likely to receive the first ACK / NACK resource and second SR resource set shown in FIG. 11A than the first SR resource and second SR resource set shown in FIG. 11B. Is large (because the Euclidean distance is short), it can be determined that the set of the first ACK / NACK resource and the second SR resource is used by the terminal. Also, the base station determines that the response signal is NACK because the combination result of the first ACK / NACK resource and second SR resource set shown in FIG. 11A is the phase point (1, 0). Can do.

In the present embodiment, in order to further improve the determination accuracy of resources used by the terminal in the base station, the terminal uses the first SR resource and the second SR resource (when only SR occurs). A signal assigned to the second SR resource and a signal assigned to the second SR resource when the first ACK / NACK resource and the second SR resource are used (when the SR and the response signal occur simultaneously). Thus, the phase rotation amounts are different from each other.

Hereinafter, the present embodiment will be specifically described.

FIG. 12 shows the configuration of base station 300 according to the present embodiment. In FIG. 12, the same components as those of base station 100 shown in FIG. 4 (Embodiment 1) are denoted by the same reference numerals, and description thereof is omitted. Here, as an example, two SR resources (for example, FIG. 6A) are notified in advance to the terminal, and despreading sections 115-1 and 115-2 and correlation processing sections 117-1 and 117-2. Is associated with the first and second SR resources, respectively.

In base station 300 shown in FIG. 12, correlation processing section 117-2 corresponding to the second SR resource includes information on correlation values (data part and reference signal part) between the despread signal and the ZAC sequence. The data is output to the determination unit 318 and the phase rotation unit 301.

The phase rotation unit 301 only applies a preset angle (eg, −90 degrees) only to the data portion of the signal input from the correlation processing unit 117-2 (ie, S ₀ to S ₃ shown in FIG. 1). Rotate the phase (ie, multiply the data part by exp (−jπ / 2)). Note that the angle set in advance in the phase rotation unit 301 is opposite to the angle (90 degrees) set in advance in the phase rotation unit 401 (FIG. 13) of the terminal 400 described later, and has the same size. . Note that the phase rotation unit 301 does not rotate the phase of the reference signal portion (ie, R ₀ to R ₂ shown in FIG. 1) of the signal input from the correlation processing unit 117-2. Then, phase rotation section 301 outputs a signal obtained by rotating the phase of the data portion (a signal obtained by multiplying the data portion by exp (−jπ / 2)) to determination section 318.

The determination unit 318 determines whether the SR and the response signal are transmitted from the terminal based on the signals (correlation values) input from the correlation processing units 117-1 to 117-n and the phase rotation unit 301. For example, the determination unit 318 determines which of the first SR resource and the second SR resource pair or the first ACK / NACK resource and the second SR resource pair is used by the terminal 400. To do.

More specifically, for example, the determination unit 318 includes a signal input from the correlation processing unit 117-1 (correlation value corresponding to the first SR resource) and a signal input from the correlation processing unit 117-2 (second The correlation values corresponding to the SR resources (without phase rotation of the data portion) are combined using MRC or the like. Similarly, determination section 318 includes a signal input from correlation processing section 117-3 (correlation value corresponding to the first ACK / NACK resource) and a signal input from phase rotation section 301 (second SR resource). And a correlation value corresponding to (with phase rotation of the data portion) are synthesized using MRC or the like.

Then, the determination unit 318 includes a combination result of the first SR resource and the second SR resource, a combination result of the first ACK / NACK resource and the second SR resource, and each combination. The closest Euclidean distance from the signal point of the response signal is obtained from the result. In addition, the determination unit 318 calculates a likelihood (likelihood) indicating how close the synthesis result of each set is to the signal point of the response signal using the obtained Euclidean distance of each set. For example, the determination unit 318 uses the reciprocal of each set of Euclidean distances as the likelihood of each set. That is, the likelihood becomes larger as the Euclidean distance is shorter.

Then, the determination unit 318 compares the likelihoods of the respective groups, and determines that the group having the higher likelihood is a group used by the terminal 400. Specifically, when the set of the first SR resource and the second SR resource has a higher likelihood than the set of the first ACK / NACK resource and the second SR resource (the signal point of the response signal and When the Euclidean distance is short), the determination unit 318 determines that the terminal 400 uses the set of the first SR resource and the second SR resource. In this case, since determination section 318 determines that only SR is transmitted from terminal 400, SR is output to an uplink resource allocation control section (not shown), and retransmission control signal generation section 119 is transmitted. To output DTX.

On the other hand, when the set of the first ACK / NACK resource and the second SR resource has a higher likelihood than the set of the first SR resource and the second SR resource (Euclidean distance from the signal point of the response signal) Is short), the determination unit 318 determines that the terminal 400 is using a combination of the first ACK / NACK resource and the second SR resource. In this case, determination section 318 outputs SR to an uplink resource allocation control section (not shown) and determines retransmission control signal generation section 119 in order to determine that SR and a response signal are transmitted from terminal 400. A response signal (ACK or NACK) is output.

Next, FIG. 13 shows the configuration of terminal 400 according to the present embodiment. In FIG. 13, the same components as those of terminal 200 shown in FIG. 5 (Embodiment 1) are denoted by the same reference numerals, and description thereof is omitted. Here, as an example, two SR resources are notified in advance to terminal 400, and first SR resource or first ACK / NACK resource is provided to uplink control channel signal generation section 213-1. Are associated with each other, and the second SR resource is associated with the uplink control channel signal generation section 213-2.

In the terminal 400 shown in FIG. 13, when the control unit 408 receives only SR from the uplink data generation unit (not shown), information corresponding to the first SR resource (ZAC sequence, cyclic shift amount, Frequency resource information, Walsh sequence and DFT sequence) are output to uplink control channel signal generation section 213-1 and information corresponding to the second SR resource (ZAC sequence, cyclic shift amount, frequency resource information, Walsh sequence and DFT sequence) ) To the uplink control channel signal generator 213-2. Further, the control unit 408 outputs an instruction signal that does not rotate the phase of the signal to the phase rotation unit 401.

On the other hand, when the control unit 408 simultaneously receives the SR and the response signal from the uplink data generation unit (not shown), the information corresponding to the first ACK / NACK resource (ZAC sequence, cyclic shift amount, frequency) (Resource information, Walsh sequence and DFT sequence) are output to uplink control channel signal generation section 213-1 and information corresponding to the second SR resource (ZAC sequence, cyclic shift amount, frequency resource information, Walsh sequence and DFT sequence) Is output to the uplink control channel signal generation section 213-2. In addition, the control unit 408 outputs an instruction signal for rotating the phase of the signal by a preset angle (for example, 90 degrees) to the phase rotation unit 401 (multiplying the signal by exp (jπ / 2)). To do.

The response signal generation unit 212 outputs the generated response signal or NACK (when there is an instruction from the control unit 408) to the modulation unit 221 and the phase rotation unit 401 of the uplink control channel signal generation unit 213-1.

The phase rotation unit 401 determines whether to rotate the phase of the signal input from the response signal generation unit 212 according to the instruction signal from the control unit 408. Specifically, when an instruction signal for rotating the phase of the signal is input from the control unit 408, the phase rotation unit 401 rotates the phase of the signal by 90 degrees (multiply the signal by exp (jπ / 2). To do). On the other hand, when an instruction signal that does not rotate the phase of the signal is input from the control unit 408, the phase rotation unit 401 does not rotate the phase of the signal (does not multiply the signal by exp (jπ / 2)). Then, the phase rotation unit 401 uses the signal after phase rotation processing according to the instruction signal (that is, a signal with phase rotation or a signal without phase rotation) as an uplink control channel signal generation unit corresponding to the second SR resource. The data is output to the modulation unit 221 of 213-2.

Next, the operation of the terminal 400 (FIG. 13) will be described. In the following description, as shown in FIG. 6A of the first embodiment, base station 300 (FIG. 12) transmits, to terminal 400, the uplink unit band shown in FIG. 2 (uplink unit band set in terminal 400). The information regarding the two SR resources is notified in advance. That is, the control unit 408 of the terminal 400 holds information regarding the two SR resources notified from the base station 300. In addition, terminal 400 identifies one or two ACK / NACK resources (FIG. 7A or FIG. 8A) associated with the CCE occupied by the downlink allocation control information received by the own device.

Hereinafter, as an example, when there are two SR resources and ACK / NACK resources that can be used in terminal 400 (FIG. 7A), the terminal according to the SR generation status and the response signal generation status in a certain subframe The detailed operation of the transmission control process at 400 will be described with reference to FIG.

In the following description, angles set in advance in the phase rotation unit 301 and the phase rotation unit 401 are set to −90 degrees and 90 degrees, respectively. In other words, values that are preset in the phase rotation unit 301 and the phase rotation unit 401 and are multiplied by the signal are expressed as exp (−jπ / 2) and exp (jπ / 2), respectively. Further, as a signal point constellation of the response signal generated by the response signal generation unit 212, ACK is associated with the phase point (-1, 0), and NACK is associated with the phase point (1, 0). .

<When both SR and response signal occur simultaneously in terminal 400>
In this case, terminal 400 transmits a response signal (“A / N”) for downlink data using the first ACK / NACK resource and the second SR resource, as in Embodiment 1 (FIG. 7B). To do. Specifically, control unit 408 of terminal 400 transmits the same response signal from antenna 1 using the first ACK / NACK resource, and transmits from antenna 2 using the second SR resource. To control.

Further, the control unit 408 instructs the response signal generation unit 212 to output the response signal input from the CRC unit 211 to the modulation unit 221 and the phase rotation unit 401 of the uplink control channel signal generation unit 213-1. To do.

The control unit 408 also causes the phase rotation unit 401 to rotate the response signal input from the response signal generation unit 212 by 90 degrees (multiply the response signal by exp (jπ / 2). ) Output the instruction signal.

Then, the phase rotation unit 401 rotates the phase of the response signal input from the response signal generation unit 212 by 90 degrees (that is, the response signal is multiplied by exp (jπ / 2)).

That is, when both SR and response signal occur simultaneously in a certain subframe (when SR and response signal are simultaneously transmitted as shown in FIG. 14), as shown in FIG. 14, the first ACK / NACK resource Then, as the signal point arrangement of the response signal (“A / N”), ACK is associated with the phase point (−1, 0), and NACK is associated with the phase point (1, 0). On the other hand, as shown in FIG. 14, in the second SR resource, ACK is associated with the phase point (0, −j) as the signal point arrangement of the response signal (“A / N”), and NACK Is associated with the phase point (0, j). That is, when both SR and a response signal occur simultaneously in a certain subframe, terminal 400 performs the second SR with respect to the constellation of the response signal allocated to the first ACK / NACK resource. The response signal constellation assigned to the resource is rotated 90 degrees. As a result, the constellation of the response signal allocated to the first ACK / NACK resource is different from the constellation of the response signal allocated to the second SR resource by 90 degrees.

However, the terminal 400 rotates only the phase of the response signal in the phase rotation unit 401 and does not rotate the phase of the reference signal (RS in FIG. 14). Therefore, as shown in FIG. 14, the reference signal (RS) transmitted by each of the first ACK / NACK resource and the second SR resource is associated with the same phase point (1, 0).

<When only a response signal is generated in terminal 400>
In this case, terminal 400 uses the first ACK / NACK resource and the second ACK / NACK resource as in Embodiment 1 (FIG. 7C) to respond to the downlink data (“A / N”). Send. Specifically, control section 408 of terminal 400 transmits the same response signal from antenna 1 using the first ACK / NACK resource, and transmits from antenna 2 using the second ACK / NACK resource. Control to do.

Further, the control unit 408 instructs the phase rotation unit 401 not to rotate the phase of the response signal input from the response signal generation unit 212 (do not multiply the response signal by exp (jπ / 2)). Output a signal.

The phase rotation unit 401 outputs the response signal input from the response signal generation unit 212 to the modulation unit 221 of the uplink control channel signal generation unit 213-2 without rotating the phase of the response signal.

That is, when only a response signal is generated in a certain subframe (when only the response signal shown in FIG. 14 is transmitted), as shown in FIG. 14, the response signal (“A / N ″), ACK is associated with the phase point (−1, 0), and NACK is associated with the phase point (1, 0). Also, as shown in FIG. 14, in the second ACK / NACK resource, ACK is associated with the phase point (−1, 0) as the signal point arrangement of the response signal (“A / N”), and NACK is the phase Corresponding to the point (1, 0). That is, when only a response signal occurs in a certain subframe, the constellation of the response signal assigned to the first ACK / NACK resource and the response signal assigned to the second ACK / NACK resource The constellation is the same.

<When only SR occurs in terminal 400>
In this case, terminal 400 transmits the SR using the same phase point as “NACK” using the first SR resource and the second SR resource, as in Embodiment 1 (FIG. 7D). Specifically, control unit 408 of terminal 400 transmits the same SR (NACK) from antenna 1 using the first SR resource and transmits from antenna 2 using the second SR resource. To control.

That is, the control unit 408 instructs the response signal generation unit 212 to output “NACK” to the modulation unit 221 and the phase rotation unit 401 of the uplink control channel signal generation unit 213-1.

The control unit 408 also sets exp (jπ / 2) to the signal (NACK) so that the phase of the signal (NACK) input from the response signal generation unit 212 is not rotated by 90 degrees with respect to the phase rotation unit 401. Output instruction signal (so as not to multiply).

Then, the phase rotation unit 401 outputs the signal (NACK) input from the response signal generation unit 212 as it is to the uplink control channel signal generation unit 213-2 without rotating the phase.

That is, when only SR occurs in a certain subframe (when only SR shown in FIG. 14 is transmitted), as shown in FIG. 14, the signal (NACK) is the phase point (1,1) in the first SR resource. 0). As shown in FIG. 14, the signal (NACK) is also associated with the phase point (1, 0) in the second SR resource. That is, when only SR occurs in a certain subframe, the constellation of SR (NACK) allocated to the first SR resource and the constellation of SR (NACK) allocated to the second SR resource Is the same.

<When neither SR nor response signal is generated in terminal 400 (not shown)>
In this case, terminal 400 does not transmit the SR and response signal in the PUCCH resource.

The detailed operation of the transmission control process in the terminal 400 according to the SR occurrence status and the response signal occurrence status has been described above.

Next, the operation of base station 300 according to the present embodiment will be described. Hereinafter, a case where both SR and a response signal are generated at the same time in a certain subframe (during simultaneous transmission of SR and a response signal shown in FIG. 14) will be described as an example. A case where the response signal is NACK will be described.

If both SR and response signals occur simultaneously in a certain subframe, as described in the first embodiment, at least one of the SR resources (here, the second SR) Resource) and at least one of the ACK / NACK resources (here, the first ACK / NACK resource) is used. That is, in terminal 400, as shown in FIG. 14, NACK (phase point (1, 0)) is assigned to the first ACK / NACK resource, and NACK (phase point (0, 0, 0)) is assigned to the second SR resource. j)) is assigned. 15A and 15B show only the components of the data portion of the data portion and the reference signal portion of the signal allocated to each resource.

In base station 300, as shown in FIG. 15A, the signal component assigned to the first ACK / NACK resource (the white circle in the first ACK / NACK resource shown in FIG. 15A) is the NACK phase point (1,0). ) (Black circle in the first ACK / NACK resource shown in FIG. 15A) and the signal component assigned to the second SR resource (white circle in the second SR resource shown in FIG. 15A) is the phase of NACK It appears near the point (0, j) (black circle in the second SR resource shown in FIG. 15A). In terminal 400, nothing is assigned to the first SR resource, but as shown in FIG. 15B, in base station 300, a noise component appears in the first SR resource. In general, the noise component appears at a position away from the NACK phase point (1, 0) (black circle in the first SR resource shown in FIG. 15B).

When the phase rotation unit 301 of the base station 300 obtains the likelihood for the set of the first ACK / NACK resource and the second SR resource, as shown in FIG. 15A, the signal obtained with the second SR resource The phase of the component (near the NACK phase point (0, j) in the second SR resource in FIG. 15A) is rotated by −90 degrees (the data portion of the correlation value is multiplied by exp (−jπ / 2)). As a result, as shown in the second SR resource of FIG. 15A, the signal component is in the vicinity of the phase point (1, 0) after the phase rotation.

Next, as illustrated in FIG. 15A, the determination unit 318 first inputs a signal component assigned to the first ACK / NACK resource (in the vicinity of the phase point (1, 0) in FIG. 15A) and the phase rotation unit 301. (That is, a signal component obtained by rotating the signal component allocated to the second SR resource by −90 degrees (a result obtained by multiplying the signal component by exp (−jπ / 2))). As a result, as shown in FIG. 15A, a signal near the phase point (1, 0) is obtained as a synthesis result.

Similarly, when determining the likelihood for the set of the first SR resource and the second SR resource, the determination unit 318, as shown in FIG. 15B, the components present in the first SR resource (in FIG. 15B, Noise component) and the signal component assigned to the second SR resource (in the vicinity of the phase point (0, j) in FIG. 15B) are combined. As a result, as shown in FIG. 15B, a signal near the phase point (0, j) is obtained as a synthesis result.

Next, the determining unit 318 calculates the likelihood calculated using the Euclidean distance between the combined signal component (combined result) and NACK (phase point (1, 0)) shown in FIG. 15A, and FIG. The likelihood calculated using the Euclidean distance between the indicated signal component (synthesis result) and NACK (phase point (1, 0)) is compared. Therefore, the determination unit 318 is more likely to use the first ACK / NACK resource and second SR resource set shown in FIG. 15A than the first SR resource and second SR resource set shown in FIG. 15B. Since the degree is large (because the Euclidean distance is short), it is determined by the terminal 400 that the set of the first ACK / NACK resource and the second SR resource is used. Also, the determination unit 318 determines that the response signal is NACK because the combination result of the first ACK / NACK resource and second SR resource combination is near the phase point (1, 0).

In this way, when the SR and the response signal are simultaneously generated in a certain subframe, the terminal 400 performs the second SR resource for the signal constellation allocated to the first ACK / NACK resource. The signal constellation assigned to is rotated 90 degrees (the signal is multiplied by exp (jπ / 2)). That is, terminal 400, as shown in FIG. 14, constellation of a signal assigned to the first ACK / NACK resource and the second SR resource when SR and the response signal are simultaneously generated in a certain subframe. Different from the constellation of the signal assigned to.

On the other hand, as shown in FIG. 14, terminal 400 uses the constellation of signals allocated to SR resources and ACK / NACK resources when only a response signal is generated within a certain subframe and when only SR is generated. Make the constellation of the assigned signals the same. That is, as shown in FIG. 14, terminal 400 changes the constellation of the signal allocated to the second SR resource when only a response signal is generated in a certain subframe or only SR is generated. I won't let you.

That is, terminal 400 changes the phase rotation amount of the signal (SR or response signal) allocated to the second SR resource depending on whether SR and the response signal are generated simultaneously in the same subframe.

In other words, terminal 400 has a phase point that can be taken by a signal assigned to the first ACK / NACK resource when SR and a response signal are simultaneously generated in a certain subframe (ACK (−1, 0 in FIG. 14)). ) And NACK (1, 0)) and a phase point (ACK (0, -j) and NACK (0, j) in FIG. 14) that can be taken by the signal allocated to the second SR resource ( (90 degrees in FIG. 14) and possible phase points (ACK (−1, 0) and NACK in FIG. 14) that can be taken by signals allocated to each resource when only SR (or response signal) occurs in a certain subframe. (1, 0)) (0 degree in FIG. 14) is made different from each other.

Specifically, as illustrated in FIG. 14, when the SR and the response signal are simultaneously generated in a certain subframe, the terminal 400 has the same content in the first ACK / NACK resource and the second SR resource. Between the phase points (for example, NACK indicating that there is an error) (phase point (1, 0) for the first ACK / NACK resource, phase point (0, j) for the second SR resource) Phase difference (90 degrees (π / 2 radians)) and only SR (or response signal) occurs in a certain subframe, each resource (for example, when only SR occurs, the first SR resource and 2 SR resources) and the phase difference (0 degree) between the phase points where the signals having the same contents (for example, NACK) are respectively arranged are made different from each other. The same applies to ACK indicating no error.

Also, here, terminal 400 arranges signals (ACK or NACK) in the first ACK / NACK resource and the second SR resource, respectively, when SR and a response signal are simultaneously generated in a certain subframe. When only a phase difference between phase points that may be generated and SR (or a response signal) occurs in a certain subframe, each resource (for example, the first SR resource and the second resource when only SR occurs) The difference between the phase difference between the phase points where the signal (ACK or NACK) may be arranged in the SR resource) is maximum (here, 90 degrees (that is, π / 2 radians)). To.

Then, in base station 300, when obtaining the likelihood for the set of the first ACK / NACK resource and the second SR resource, the phase of the reverse rotation with respect to terminal 400 is performed with respect to the data portion of the second SR resource. In contrast to the rotation, when the likelihood for the other set of resources is obtained, the phase rotation is not applied to the data portion of the second SR resource. That is, base station 300 uses a set of first ACK / NACK resource and second SR resource by terminal 400 (that is, when terminal 400 performs phase rotation on the second SR resource). ), The second SR resource in the correct resource set (that is, the first ACK / NACK resource and the second SR resource set) is rotated in the opposite phase to terminal 400. Thus, phase rotation is not performed on the second SR resource in the wrong resource set (that is, other resource set). Similarly, when the terminal 400 uses another set of resources (that is, when the terminal 400 does not perform phase rotation with respect to the second SR resource), the base station 300 determines the correct resource. While the phase rotation is not performed on the second SR resource in the set (that is, the set of resources other than the set of the first ACK / NACK resource and the second SR resource), the wrong set of resources Phase rotation is performed on the second SR resource in (that is, the set of the first ACK / NACK resource and the second SR resource).

Therefore, in base station 300, the combination result after MRC in the wrong resource set of the first ACK / NACK resource and second SR resource set and other resource sets, and the signal of the response signal A phase difference corresponding to the amount of phase rotation occurs between the points. For example, in FIG. 15A, the combination result after MRC (in the vicinity of the combined phase point (1, 0)) in the first ACK / NACK resource and second SR resource set (here, the correct resource set) is the response. It is located near the signal point (1,0) of the signal. On the other hand, in FIG. 15B, the combination result after MRC in the set of the first SR resource and the second SR resource (here, the incorrect set of resources) (near the phase point (0, j) after the combination) Is a position where the phase difference from the signal point (1, 0) of the response signal is approximately 90 degrees (π / 2 radians) (the amount of phase rotation given by the terminal 400).

That is, in base station 300, among the first ACK / NACK resource and second SR resource sets and other resource sets, an incorrect resource set (that is, a resource set not used by terminal 400). ) Is likely to be far away from the signal point of the response signal.

Thereby, the base station 300 has a likelihood calculated based on an incorrect resource set (for example, in FIG. 15A and FIG. 15B, the first SR resource and second SR resource set shown in FIG. 15B). There is a possibility of degrading much more than the likelihood calculated based on the correct resource set (for example, in FIGS. 15A and 15B, the first ACK / NACK resource and the second SR resource set shown in FIG. 15A). Is expensive. For example, comparing FIG. 11B (when phase rotation is not performed with the second SR resource) and FIG. 15B (when phase rotation is performed with the second SR resource), an incorrect resource set (here, the first In FIG. 15B, the Euclidean distance between the combination result in the combination of the SR resource and the second SR resource) and the signal point of the response signal is longer than that in FIG. 11B. That is, the likelihood of the wrong resource set in FIG. 15B is significantly degraded from the likelihood of the wrong resource set in FIG. 11B. That is, the difference between the likelihood of the correct resource set in FIG. 15A and the likelihood of the incorrect resource set in FIG. 15B is the likelihood of the correct resource set in FIG. 11A and the likelihood of the incorrect resource set in FIG. Greater than the difference in degrees.

Thus, in the base station 300, the difference in likelihood can be greatly different between the correct resource set and the incorrect resource set. For this reason, it is possible to improve the determination accuracy for determining which of the first ACK / NACK resource and second SR resource set and the other resource set is used by the terminal 400.

Thus, according to the present embodiment, in the LTE-A system, a subframe in which a base station should receive a response signal from a terminal (that is, a response if the terminal has correctly received downlink allocation control information). Signal transmission subframe), even if SR occurs on the terminal side, the base station can more accurately determine whether the terminal side has received downlink allocation control information or not, and improve retransmission efficiency. be able to.

In the present embodiment, when SR and a response signal are generated simultaneously on the terminal side, the constellation of the second SR resource is rotated 90 degrees (phase) with respect to the constellation of the first ACK / NACK resource. Rotation), that is, an operation of multiplying the signal of the second SR resource by exp (jπ / 2) = j, exp (jπ / 2) is regarded as a scramble code and may be referred to as scramble. . Accordingly, the phase rotation unit 401 may be referred to as a scramble unit.

Also, in the present embodiment, when the SR and the response signal are simultaneously generated on the terminal side, the second SR resource constellation is rotated by 90 degrees with respect to the first ACK / NACK resource constellation. Explained. However, on the terminal side, the constellation of the second SR resource is rotated by an arbitrary angle θ (radian) with respect to the constellation of the first ACK / NACK resource (exp ( In the case of multiplying jθ), the same effect as this embodiment can be obtained. For example, as a typical rotation angle, in addition to 90 degrees, −90 degrees (that is, when multiplying the signal of the second SR resource by exp (−jπ / 2) = − j), or 180 degrees ( In other words, the signal of the second SR resource is multiplied by exp (−jπ) = − 1).

Also, in the present embodiment, as the order of processing on the terminal side, after performing phase rotation (that is, multiplication by exp (jπ / 2) which is a scramble code), primary spreading and secondary spreading are performed. explained. However, the order of scramble processing, primary spreading, and secondary spreading is not limited to this. That is, since the scramble process, the first spread and the second spread are all represented by multiplication, for example, after the first spread is performed on the response signal or the second spread is performed, the scramble code is changed. Even if multiplication is performed, the same result as in the present embodiment can be obtained.

The embodiments of the present invention have been described above.

In the above embodiment, a case has been described in which a ZAC sequence is used for primary spreading in a PUCCH resource, and a pair of Walsh sequence and DFT sequence is used as an orthogonal code sequence for secondary spreading. However, in the present invention, sequences that can be separated from each other by different cyclic shift amounts other than ZAC sequences may be used for the first spreading. For example, a GCL (Generalized Chirp like) sequence, a CAZAC (Constant Amplitude Zero Auto Correlation) sequence, a ZC (Zadoff-Chu) sequence, a PN sequence such as an M sequence or an orthogonal gold code sequence, or a time randomly generated by a computer A sequence having a sharp autocorrelation characteristic on the axis may be used for the first spreading. For secondary spreading, any sequence may be used as the orthogonal code sequence as long as the sequences are orthogonal to each other or sequences that can be regarded as being substantially orthogonal to each other. In the above description, the response signal resource (for example, PUCCH resource) is defined by the cyclic shift amount of the ZAC sequence and the sequence number of the orthogonal code sequence.

Further, in the above embodiment, when L1 / L2CCH occupies N (N> 2) CCEs, the terminal (terminal 200, terminal 400) has two ACK / links associated with any two CCEs. The case where the NACK resource is selected has been described. However, attention is paid to the fact that the intersymbol interference between two ACK / NACK resources associated with consecutive CCEs with an Index is large. For example, the ACK / NACK resource associated with the CCE with the smallest Index and the Index with N Two ACK / NACK resources of the ACK / NACK resource associated with the CCE / 2 may be used. Thereby, the interference between two ACK / NACK resources can be reduced, and the transmission performance of a response signal can be improved.

In the above embodiment, the case where the response signal transmitted from the terminal is modulated by BPSK has been described. However, the present invention can be applied to a case where the response signal is not limited to BPSK but is modulated by QPSK, for example. For example, in the second embodiment, when an SR and a response signal occur simultaneously in a certain subframe, the terminal rotates the phase of the response signal allocated to the second SR resource by 45 degrees. By multiplying the response signal by exp (jπ / 4), the same effect as in the above embodiment can be obtained.

In the above embodiment, the antenna is described as an antenna. However, the present invention can be similarly applied to an antenna port.

An antenna port refers to a logical antenna composed of one or more physical antennas. That is, the antenna port does not necessarily indicate one physical antenna, but may indicate an array antenna composed of a plurality of antennas.

For example, in 3GPP LTE, it is not specified how many physical antennas an antenna port is composed of, but it is specified as a minimum unit in which a base station can transmit different reference signals (Reference signal).

Also, the antenna port may be defined as a minimum unit for multiplying the weight of a precoding vector (Precoding vector).

Further, although cases have been described with the above embodiment as examples where the present invention is configured by hardware, the present invention can also be realized by software.

Further, each functional block used in the description of the above embodiment is typically realized as an LSI which is an integrated circuit. These may be individually made into one chip, or may be made into one chip so as to include a part or all of them. Although referred to as LSI here, it may be referred to as IC, system LSI, super LSI, or ultra LSI depending on the degree of integration.

Also, the method of circuit integration is not limited to LSI, and may be realized by a dedicated circuit or a general-purpose processor. An FPGA (Field Programmable Gate Array) that can be programmed after manufacturing the LSI or a reconfigurable processor that can reconfigure the connection and setting of circuit cells inside the LSI may be used.

Furthermore, if integrated circuit technology that replaces LSI emerges as a result of advances in semiconductor technology or other derived technology, it is naturally also possible to integrate functional blocks using this technology. Biotechnology can be applied.

The disclosure of the specification, drawings and abstract contained in the Japanese application of Japanese Patent Application No. 2010-029051 filed on February 12, 2010 is incorporated herein by reference.

The present invention can be applied to a mobile communication system or the like.

100, 300

Base station

200, 400

Terminal

101, 208, 408 Control unit 102 Control

information generation unit

103, 105

Coding unit

104, 107, 221 Modulation unit 106 Data transmission control unit 108

Mapping unit

109, 223, 226

IFFT unit

110 , 224, 227 CP addition unit 111, 214

Radio transmission unit

112, 201

Radio reception unit

113, 202 CP removal unit 114 PUCCH extraction unit 115 Despreading unit 116 Sequence control unit 117

Correlation processing unit

118, 207, 318 Determination unit 119 Retransmission Control signal generation unit 203 FFT unit 204

Extraction unit

205, 209

Demodulation unit

206, 210 Decoding unit 211 CRC unit 212 Response signal generation unit 213 Uplink control channel

signal generation unit

222, 225, 228 Spreading unit 229

Multiplexing unit

301, 401 Phase rotation Part

Claims

Either one of a response signal based on an error detection result of downlink data or an uplink control signal indicating the occurrence of uplink data is allocated to a code resource, and the response signal or the uplink control signal allocated to the code resource is assigned to a plurality of A terminal device for transmitting from each antenna;
Receiving means for receiving the downlink data assigned to the downlink data channel;
Generating means for generating the response signal based on an error detection result of the downlink data;
Transmitting means for transmitting the response signal or the uplink control signal using the code resource;
Control means for controlling transmission of the response signal or the uplink control signal based on the generation state of the response signal and the uplink control signal,
When the uplink control signal and the response signal are simultaneously generated within a transmission unit time, the control means is assigned the uplink control signal when only the uplink control signal is generated within the transmission unit time. At least one resource among the first code resources, and at least one resource among the second code resources to which the response signal is assigned when only the response signal occurs within the transmission unit time; The response signal is transmitted using
Terminal device.
The control means further includes the at least one resource among the first code resources and the second resource when the uplink control signal and the response signal are generated simultaneously within the transmission unit time. A first phase difference between phase points at which signals of the same content are arranged in at least one of the code resources of
When only the uplink control signal is generated within the transmission unit time, the second phase difference between the phase points at which signals having the same content are respectively arranged in the plurality of second code resources is made different from each other. ,
The terminal device according to claim 1.
The control means includes a constellation of the response signal allocated to the at least one resource among the first code resources when the uplink control signal and the response signal are simultaneously generated within the transmission unit time. Different from the constellation of the response signal allocated to the at least one resource among the second code resources,
A constellation of a signal allocated to the first code resource when only the response signal occurs within the transmission unit time and when only the uplink control signal occurs within the transmission unit time, and the second Make the constellation of signals allocated to code resources the same,
The terminal device according to claim 2.
The control means, when the uplink control signal and the response signal are simultaneously generated within the transmission unit time, the constellation of the response signal allocated to the at least one resource among the first code resources In contrast, the constellation of the response signal allocated to the at least one resource among the second code resources is rotated by 90 degrees.
The terminal device according to claim 3.
When the uplink control signal and the response signal are generated at the same time within the transmission unit time, the control means uses exp () for the response signal assigned to the at least one resource among the first code resources. jπ / 2),
The terminal device according to claim 3.
Either one of a response signal based on an error detection result of downlink data or an uplink control signal indicating the occurrence of uplink data is allocated to a code resource, and the response signal or the uplink control signal allocated to the code resource is assigned to a plurality of A signal transmission control method in a terminal device for transmitting from an antenna,
Receiving the downlink data assigned to the downlink data channel; and
Generating the response signal based on an error detection result of the downlink data;
A transmission step of transmitting the response signal or the uplink control signal using the code resource;
A control step of controlling transmission of the response signal or the uplink control signal based on the generation status of the response signal and the uplink control signal,
In the control step, when the uplink control signal and the response signal are generated simultaneously within a transmission unit time, the uplink control signal is assigned when only the uplink control signal is generated within the transmission unit time. At least one resource among the first code resources, and at least one resource among the second code resources to which the response signal is assigned when only the response signal occurs within the transmission unit time; The response signal is transmitted using
Signal transmission control method.