+

WO2008025366A1 - Procédé et agencement pour une signalisation d'adaptation de liaison dans un réseau de communication sans fil - Google Patents

Procédé et agencement pour une signalisation d'adaptation de liaison dans un réseau de communication sans fil Download PDF

Info

Publication number
WO2008025366A1
WO2008025366A1 PCT/EP2006/008435 EP2006008435W WO2008025366A1 WO 2008025366 A1 WO2008025366 A1 WO 2008025366A1 EP 2006008435 W EP2006008435 W EP 2006008435W WO 2008025366 A1 WO2008025366 A1 WO 2008025366A1
Authority
WO
WIPO (PCT)
Prior art keywords
coding
modulation
mobile station
wireless communication
communication network
Prior art date
Application number
PCT/EP2006/008435
Other languages
English (en)
Inventor
Lei Wan
Magnus Almgren
Original Assignee
Telefonaktiebolaget Lm Ericsson (Publ)
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Telefonaktiebolaget Lm Ericsson (Publ) filed Critical Telefonaktiebolaget Lm Ericsson (Publ)
Priority to PCT/EP2006/008435 priority Critical patent/WO2008025366A1/fr
Priority to TW096122122A priority patent/TW200816754A/zh
Publication of WO2008025366A1 publication Critical patent/WO2008025366A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W28/00—Network traffic management; Network resource management
    • H04W28/16—Central resource management; Negotiation of resources or communication parameters, e.g. negotiating bandwidth or QoS [Quality of Service]
    • H04W28/18—Negotiating wireless communication parameters
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
    • H04L1/0002—Systems modifying transmission characteristics according to link quality, e.g. power backoff by adapting the transmission rate
    • H04L1/0003—Systems modifying transmission characteristics according to link quality, e.g. power backoff by adapting the transmission rate by switching between different modulation schemes
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
    • H04L1/0009—Systems modifying transmission characteristics according to link quality, e.g. power backoff by adapting the channel coding
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
    • H04L1/0023—Systems modifying transmission characteristics according to link quality, e.g. power backoff characterised by the signalling
    • H04L1/0025—Transmission of mode-switching indication

Definitions

  • the present invention is generally related to communications networks and a link adaptation signalling design to support the continuous code-rate adaptation, which is suitable to a packet centric protocol as well.
  • 3G mobile networks such as WiMAX or the high-speed version of 3G mobile networks, such as the HSPDA (High Speed Data Access)
  • WiMAX Wireless Fidelity
  • 3G mobile networks such as the HSPDA (High Speed Data Access)
  • OFDM-technique Orthogonal Frequency Division Multiplexing
  • the OFDM-scheme also allows for FDA (Frequency Domain Adaptation) strategies in order to improve user throughput and coverage.
  • FDA Frequency Domain Adaptation
  • LA link adaptation
  • Scheduling involves among others attempting to find radio resources to be used for power allocation among the users to be served.
  • PA Power Allocation
  • CQ channel quality
  • SINR Signal-to-lnterference-and-Noise-Ratio
  • a more realistic optimisation strategy would be to optimize the three parameters separately with respect to user throughput and coverage subject to the constraint of total transmitted power and QoS (Quality of Service) for all users.
  • code-rates Y 2 , 2/3, 3 A, 5/6 for CTC (Convolutional Turbo coding) and QPSK (Quaternary Phase Shift Keying), 16QAM (16-ary Quadrature Amplitude Modulation) and 64QAM (64-ary Quadrature Amplitude Modulation) are specified in the wireless standard WiMAX described in IEEE P802.16e/D12, "Local and metropolitan area networks Part 16: Air Interface for Fixed and Mobile Broadband Wireless Access Systems Amendment for Physical and Medium Access Control Layers for Combined Fixed and Mobile Operation in Licensed Bands", October 2005.
  • HSDPA High Speed Data Packet Access
  • the coded & modulated block size is already covered by the scheduling signalling, such as shown in Fig. 1 , but the transport block-size is not explicitly given by the signalling.
  • WiMAX introduces the MCS indexes in the link adaptation signalling.
  • the transport block-size can be calculated based on the combination index in TFRI (Transport Format Resource Index) and an extra indicator of the number of the remnant bits, such as described in 3GPP TS 25.321 , "Medium Access Control (MAC) protocol specification", V5.10.0, Dec. 2004.
  • the packet size denoted as the MAC PDU (Media Access Control Packet Data Unit) size differs for different services and might even vary from time to time.
  • extra padding bits generally zero bits
  • the number of padded bits in the transport block is not covered by the physical-layer signalling. Instead, the transmitter has to inform the MAC PDU size to the receiver by higher-layer signalling, i.e. through MAC layer signalling.
  • the system can operate in a very flexible bandwidth from 1.25MHz to 20MHz, and one user can be scheduled to any size of the radio resource, thus there is almost no limit on the coded block size.
  • the coarse MCS granularity limits the throughput performance due to the number of bits to be padded in order for the MAC PDU to fit the transport block size - especially in the cellular systems.
  • the padded bits do not provide any coding gain, which is a waste of the extra redundancy bits.
  • the signalling about the link adaptation information consists of information about both the transport block size and the MAC PDU size so as to be able to remove the padded bits in the disassembly entity in the receiver end.
  • the number of padded bits to be added to the transport block and the MCS are determined by link adaptation. Padding bits before the encoder is not suitable for a packet centric protocol, such as WINNER, which implements channel coding ahead of scheduling and link adaptation.
  • link adaptation signalling in existing systems has the following disadvantages: • Signalling using the MCS index only supports the discrete code-rate adaptation, where the code-rate granularity limits the performance in the cellular system
  • Discrete code-rate candidates require extra padded bits to fill the packet into the allocated resource, thus the link adaptation signalling cost is noticeable even when only a few MCS candidates are used due to the extra signalling of the MAC PDU size or the number of padded bits.
  • the padded bits do not provide any coding gain, which is a waste of the redundancy bits.
  • the object of the invention is to obviate at least some of the disadvantages with known technology.
  • the object of the invention is achieved by ajnethod for link adaptation signalling in a wireless communication network comprising at least one transmitter and one receiver, including the steps of determining the channel quality parameters at the receiver, based on the channel quality parameters determined, allocating radio resources for at least one user in the wireless communication network
  • the method according to the present invention is further characterized by the steps of selecting the coding and modulation type from the available coding and modulation candidates for user data to fully fill the allocated radio resource, informing the receiver about the modulation mode used for user data, informing the receiver about the size of a source data packet by which the coding rate can be obtained before coding of the user data and coding and modulating the user data according to the coding and modulation candidates selected.
  • the size of a source data packet is based on the allocated radio resource for at least one user and the received modulation mode.
  • the advantage of this dependency is the further reduction of signalling bits needed to inform the receiver about the size of the source data packet.
  • the coding type and modulation mode selection may be performed for each individual user radio resource allocated.
  • Another possibility would be to classify individually allocated user radio resources into groups and to select the coding rate and modulation type separately for each such group. This would mean that the signalling for each such group or user radio resources would be performed separately.
  • One other possibility would be to classify individually allocated user radio resources into groups and to select the coding for each such group, while choosing the modulation mode to be the same for all such groups. Yet another option would be to select the modulation mode for each allocated user radio resource individually, while choosing the coding rate to be the same for all allocated user radio resources.
  • the number of coding rates and modulation modes is chosen so as to fully fill any allocated radio resource up to the maximum allowed amount of radio resources. Therefore, the only upper bound for the size of the transport block to be sent to the user is the maximum allowable transport block size.
  • the channel quality parameters mentioned above may comprise one of the parameters SINR (Signal-to-lnterference-and-Noise-Ratio), Mutual information, RBIR (Received Bit Information Rate), throughput, spectral efficiency, BLER (Block Error-Rate) or other parameters suitable for characterizing the CQ. (Channel Quality).
  • SINR Signal-to-lnterference-and-Noise-Ratio
  • RBIR Receiveived Bit Information Rate
  • throughput spectral efficiency
  • BLER Block Error-Rate
  • BLER Block Error Rate
  • BLER or Block Error Rate may be defined as the ratio between the number of incorrectly received data blocks and the total number of data blocks received. It may be added that the BLER is a not a measured, but a purely empirical parameter.
  • the allocated radio resource for each user may comprise chunks, where the chunks being are one or more sub-carrier frequencies in OFDM channels.
  • the coding may be selected among a plurality of continuous coding rates for CTC (Convolutional Turbo Coding), convolutional code, BTC (Block Turbo Coding), LDPC (Low Density Parity Check) and other suitable coding, where a coding rate is selected so as to satisfy a predefined BLER (Block Error Rate) target.
  • the coding rates may be defined as representing the ratio between the number of information bits and the number of redundant bits.
  • the BLER TA R G E T may be defined as the desired BLER for the received signal, and therefore, strictly speaking, is not a rigid upper bound for the BLER.
  • the coding may be selected among a plurality of discrete coding rates for CTC, convolutional code, BTC (Block Turbo Coding), LDPC (Low Density Parity
  • the modulation modes mentioned earlier may be selected among a plurality of modulation modes from QPSK (Quaternary Phase Shift Keying), 16QAM (16-ary Quadrature Amplitude Modulation), 64QAM (64-ary Quadrature Amplitude Modulation) and other modulation modes suitable for communication in wireless communication networks.
  • QPSK Quadrature Phase Shift Keying
  • 16QAM 16-ary Quadrature Amplitude Modulation
  • 64QAM 64-ary Quadrature Amplitude Modulation
  • One example of a source packet size in a wireless communication network may comprise the MAC PDU size (Media Access Control Packet Data Unit).
  • MAC PDU size Media Access Control Packet Data Unit
  • the only constraint on the MAC PDU size would be the maximum allowed transport block size.
  • the method according to the present invention may preferably be implemented in a wireless communication network belonging to the group of wireless telecommunication networks, such as, for example, a Wireless LAN, WiMAX, WINNEX, HiperLan or other wireless communication networks suitable for the link adaptation signalling mentioned above.
  • a wireless communication network belonging to the group of wireless telecommunication networks, such as, for example, a Wireless LAN, WiMAX, WINNEX, HiperLan or other wireless communication networks suitable for the link adaptation signalling mentioned above.
  • a mobile station for communication in a wireless communication network comprising a device for determining channel quality parameters on a radio link, at least one transmitter for sending information indicative of the channel quality on the radio link to a node in the wireless communication network based on the channel quality parameters determined, at least one receiver for receiving information indicative of the radio resource allocated to the mobile station by the node in the wireless communication network based on the information indicative of the channel quality on the radio link, where the mobile station is further arranged to negotiate with the node in the wireless communication network the type of modulation to be used for a data signal to be transmitted to or via the node and the number of bits in a source data packet before coding the information in the source data packet.
  • the mobile station may further comprise a device for modulation and coding of a data signal according to the type of modulation and the number of coding bits negotiated with the node.
  • the mobile station may be further arranged to send information about the type of modulation and coding for a data signal to the node in the wireless communication network.
  • the mobile station may be further arranged to receive information about the type of modulation and coding for a data signal from the node in the wireless communication network.
  • the node in the wireless communication network may for example be a base station transceiver, but could as well be any other node suitable for performing the signalling mentioned above..
  • a base station for communication in a wireless communication network comprising at least one receiver for receiving information indicative of channel quality, at least one transmitter for sending information indicative of reservation of radio resources for a mobile station in the wireless communication network based on the information indicative of channel quality, wherein the base station is further arranged to negotiate with the mobile station the type of modulation to be used for a data signal to be transmitted to the mobile station and the number of bits in a source data packet before coding the information in the source data packet and where the base station further comprises a device for modulation and coding of a data signal according to the type of modulation and the number of coding bits negotiated with the node.
  • the object of the invention is achieved by a network infrastructure for a wireless communication network comprising a at least one mobile station and one base station, where the at least one mobile station and base station comprise at least one receiver and one transmitter, where the at least one mobile station and one base station further comprise devices for determining channel quality parameters of a wireless connection, wherein the at least one receiver and transmitter of the at least one mobile station and base station are arranged to receive or transmit information indicative of the channel quality of a wireless connection based on the channel quality parameters determined which is characterised by that the at least one mobile station and base station are further arranged to negotiate the type of modulation to be used for a data signal and the number of bits in a source packet before coding the information in the packet and where the at least one mobile station and base station each comprise a device for modulation and coding of a data signal according to the type of modulation and the number of coding bits negotiated.
  • the method according to the present invention is suitable to be performed in the communication between the mobile station and the base station in the communication infrastructure described earlier.
  • the object of the invention is achieved by a computer program for link adaptation signalling in a wireless communication network comprising an instruction set for determining channel quality parameters for a radio link, an instruction set for allocating radio resources for each user in the communication network based on the channel quality parameters determined, an instruction set for selection of coding and modulation type from the available coding modulation candidates for user data to fully fill the allocated radio resource, an instruction set for informing the receiver about the coding and modulation used on user data, an instruction set for informing the receiver about the size of the source packet before channel coding and finally an instruction set for coding and modulating the channel according to the coding and modulation candidates selected.
  • the computer program according to the present invention is especially suited to implement the steps of the method according to the present invention.
  • Fig. 1 illustrates in a schematical way link adaptation signalling according to known technology.
  • Fig. 2 illustrates a flow chart according to a method of the present invention.
  • Fig. 3 illustrates a mobile station according to the present invention.
  • Fig. 4 illustrates a base station according to the present invention
  • Fig. 5 illustrates a first diagram over a performance comparison between discrete and continuous code-rate adaptation used in a receiver/transmitter with SISO (Single Input Single Output) for the 5 th percentile user throughput at the cell edge.
  • SISO Single Input Single Output
  • Fig. 6 illustrates a second diagram over a performance comparison between discrete and continuous code-rate adaptation used in a receiver/transmitter with SISO for the average cell throughput.
  • Fig. 7 illustrates a third diagram over a performance comparison between discrete and continuous code-rate adaptation used in a receiver/transmitter with 1x2 SIMO (Single Input Multiple Outputs) receiver diversity for the 5 th percentile user throughput at the cell edge.
  • 1x2 SIMO Single Input Multiple Outputs
  • Fig. 8 illustrates a fourth diagram over a performance comparison between discrete and continuous code-rate adaptation used in a receiver/transmitter with 1x2 SIMO receiver diversity for average throughput per cell.
  • Fig. 1 is a schematical view over LA (Link Adaptation) signalling according to known technology.
  • Coded and modulated data in the form of information bits (IB) is to be inserted into a transport block of a certain allocated size. If the length of the information bit block is less than the allocated transport block size the remaining space is filled with padded bits (PB).
  • PB padded bits
  • the number of padded bits is signalled from the transmitter of user data to the receiver.
  • the thus coded and modulated symbols block is sent over the radio link to the receiver.
  • Signalling about the coding rate and the modulation mode for user data is performed at the physical layer here.
  • Fig. 2 illustrates one possible embodiment of a method according to the present invention.
  • the method describes the link adaptation signalling between a mobile station (UE - User Equipment) and a base station in a wireless communication network.
  • the communication between a mobile station (UE) and a base station (BS) is schematically illustrated.
  • the UE may be any type of user equipment capable of communicating with similar UE:s in a wireless communication network, and hence is not limited to a particular type of mobile device.
  • the base station mentioned above may be a Node B or some other type of base station equipment, such as, for example, an access point in a wireless communication network.
  • the mobile station measures the quality of the wireless link from received data by comparing it with a desired link quality.
  • the parameter to be determined may for example be the SINR (Signal-to-Noise-and-lnterference-Ratio) for a signal previously received from a Node B and is defined as a CQI (Channel Quality Information).
  • CQI Channel Quality Information
  • Other parameters for measuring the quality of the wireless link may be mutual information, RBIR (Received Bit Information Rate), BLER (Block Error-Rate) or other parameters suitable for characterizing the CQ. (Channel Quality) and which are well known to the skilled person.
  • the determined CQI is, for example, transmitted on an available control channel from the UE to a Node B at step 110.
  • the Node B Based on the received CQI from the UE, the Node B allocates radio resources, which in the case of OFDM (Orthogonal Frequency Division Multiplexing) for the downlink, may be allocated as resource blocks or chunks, where each chunk may comprise one or more sub-carriers used for data transmission on the OFDM downlink.
  • radio resources which in the case of OFDM (Orthogonal Frequency Division Multiplexing) for the downlink, may be allocated as resource blocks or chunks, where each chunk may comprise one or more sub-carriers used for data transmission on the OFDM downlink.
  • OFDM Orthogonal Frequency Division Multiplexing
  • the Node B selects a coding rate for the data to be transmitted to the UE.
  • This may be a discrete coding rate or a coding rate chosen from a range of continuous coding rates, where, for example, the coding rates are expressed as the ratio between the number of redundant bits and the number of data bits used for coding and may range between 0.1 and 0.99 in steps of 0.01.
  • the coding of the signal may be performed using CTC (Convolutional Turbo Coding), convolutional code, BTC (Block Turbo Coding), LDPC (Low Density Parity Check) or other suitable coding.
  • CTC Convolutional Turbo Coding
  • BTC Block Turbo Coding
  • LDPC Low Density Parity Check
  • the coded signal has to satisfy certain conditions related to the characteristics of the radio link between the UE and the Node B.
  • BLEP is the Block Error Probability and is a parameter derived from BLER (Block Error Rate).
  • BLER was defined as the ratio of the number of erroneously received data blocks to the number of total data blocks received.
  • the unit receiving the data blocks is the UE.
  • BLEP may then be defined as the expected BLER, where several BLER measurements are taken into consideration.
  • BO BLER is a type of safety margin in case the CQI sent from the UE is not entirely accurate. This may occur due to changing transmission and reception conditions on the radio link, which are, as is well known, subject to frequent changes.
  • step 130 When using discrete coding rates it is checked at step 130 whether the chosen highest coding rate satisfies the BLEP condition. If yes, a suitable modulation mode for the data signal to be sent to the user is selected at the next step 140. If not, the next highest coding rate is chosen among the remaining coding rate candidates and the check if the BLEP-condition above is satisfied is performed again. However, when using continuous coding rates, the coding rate that just satisfies the BLEP-condition is chosen.
  • NormTP ModOrder * Cr * (1 -BLER).
  • NormTP is the normalized user throughput. In case the selected modulation mode does not satisfy the condition of maximum normalized user throughput the next modulation mode is chosen and the check is performed again.
  • data to be sent to the UE is encoded and modulated using the coding rate and modulation mode selected earlier.
  • the modulation mode and the number of information bits in the data to be sent to the UE are signalled on an available control channel to the UE at step 170.
  • Node B may send the information in the form of a modulation mode index expressed through a number of bits.
  • BPSK Binary Phase Shift Keying
  • QPSK Quadrature Phase Shift Keying
  • 16 QAM 16-ary Quadrature Amplitude Modulation
  • 64 QAM 64-ary Quadrature Amplitude Modulaiton
  • the measuring of the SINR or some other channel quality parameter performed by the UE at step 100 is performed continuously, as transmission conditions on the radio link are bound to change constantly.
  • LAO chunk-wise MCS selection, i.e. modulation and coding rate adapt to the channel chunk by chunk.
  • LA1 Multiple coding rates with chunk-wise modulation adaptation. The chunks are classified to a few groups to keep small CQ variation within each group. The coding rate adaptation is done for each group.
  • LA2 Multiple coding rates, with single modulation mode for each coding rate, i.e. group- wise MCS adaptation.
  • the grouping process is same as LA1.
  • LA3 Single coding rate, with chunk-wise modulation adaptation.
  • LA4 Single MCS for all the chunks.
  • the LAO to LA3 schemes are frequency-domain LA, which requires extra signalling to support different MCS for different chunks.
  • LA4 is the time-domain link adaptation, where a common MCS is used for all the chunks.
  • Link adaptation signalling by the Node B at step 170 may also be performed in a separate control message to the UE before sending data modulated and coded with the signalled modulation mode and coding rate to the UE.
  • the link adaptation signalling may be part of the data packet sent to the UE by the Node B.
  • the present invention is basically applicable to any type of communication network where there is a communication link, be it a wireless or a wirebound communication network, where there are a multitude of symbols allocated for a specific transmission (i.e. a data packet) and where each symbol is transmitted with a certain expected quality when transmitted.
  • Fig. 3 a schematical view (not drawn to scale) is shown over a UE (User Equipment) according to an embodiment of the present invention and a BS (Base Station) in a wireless communication network and the signalling between the two devices. For clarity purposes, the rest of the network is not shown.
  • the direction of data transmission is in the downlink direction, i.e. from the BS to the UE.
  • the UE comprises a receiver/transmitter 210 receiving data from the BS and sending data to the BS.
  • the receiver and transmitter may also be separate units and the UE may also comprise more than one receiver and transmitter.
  • the UE Apart from receiving data from the BS the UE also receives control information on a control channel, where it is by way of example informed about the radio resources allocated to it.
  • the UE comprises a unit 220 for determining the SINR of the radio link on which the UE and the BS communicate. Normally, the SINR of a signal received from the BS at the receiver/transmitter 210 is used to determine the SINR in the unit 220.
  • a data signal sent by the BS and received at the UE is schematically shown by the arrow 240.
  • the unit 220 may also measure any other signal parameter associated with channel quality based on the signal received from the BS.
  • the UE may also measure other parameters relevant for the quality of the radio link between the UE and BS, such as RBIR (Received Bit Information Rate), RSSI (Received Signal Strength Indication) and other parameters relevant for characterizing the reception and transmission conditions on the radio link.
  • the UE also comprises a unit 230 for selecting a TFRC (Transport Format Resource Combination) referring to possible transport block sizes, modulation schemes, and other relevant link adaptation parameters.
  • TFRC Transport Format Resource Combination
  • This unit compiles a message CQI (Channel Quality Indicator) to be sent to the BS via the receiver/transmitter 210 indicated by the arrow 242.
  • CQI Channel Quality Indicator
  • the BS sends the data signal modulated according to the modulation retrieved from the information message sent by the UE to the UE as indicated by the arrow 248.
  • the coded and modulated data signal may in a control channel comprise data indicative of the modulation mode and the coding rate used for the data signal.
  • this information may also be sent separately in a control message to the UE, before sending the data signal.
  • the unit 230 for selecting a TFRC may not necessarily be located in the UE, but equally be part of the BS.
  • the CQI message sent from the UE to the BS would in this case be much simpler and containing information indicative of the SINR measured, while the calculations as to which coding rate and modulation mode should be chosen, would be performed by the BS.
  • Fig. 4 illustrates a BS, a UE and the communication between them according to another embodiment of the present invention.
  • the UE is essentially the same mobile unit as in Fig. 3 (hence the same reference), but without the unit 230 for selecting the suitable coding rate and modulation mode. Instead the UE basically only has the ability to transmit, receive and measure the channel quality on the radio link and to send the information as CQI to the BS (not shown).
  • the BS likewise has a receiver/transmitter 310 for receiving and sending data and control signals from and to the UE, a device 320 for measuring the quality of the radio link and a unit 330 for selecting a suitable combination of modulation mode and coding rate for a data signal in order to fully fill a transport block and to code the data signal according to these parameters.
  • the BS may comprise more than one receiver or transmitter 310.
  • Link adaptation signalling between the UE and the Bs is indicated by the arrows numbered 330-338.
  • the BS sends a data signal to the UE indicated by the arrow 330.
  • the UE measures the quality of the radio link by for example determining the SINR for the received signal. This information is sent back as CQI (Channel Quality Indication) as indicated by the arrow 332.
  • CQI Channel Quality Indication
  • the BS determines in the unit 330 the combination of coding rate and modulation mode which will fully fill an information block, provide maximum user throughput while at the same time satisfy the constraint of a given BLER (Block Error Rate) target.
  • BLER Block Error Rate
  • a data signal is then coded and modulated according to the selected combination and sent to the UE via the receiver/transmitter 310.
  • Signalling is further reduced by introducing variable signalling bits on the transport block-size (or MAC PDU size) based on the scheduling signalling and modulation mode.
  • the optimal modulation mode and code-rate is selected in order to maximize the user throughput according to the instantaneous channel quality information.
  • the selected code-rate just satisfies the BLER TARGET requirement.
  • the discrete code-rate adaptation among all the MCSs that satisfy the BLER TARG ET > the MCS that closest to the BLER TARGET is selected.
  • This section gives the simulation results of different link adaptation schemes with both the continuous coding rate adaptation and the discrete coding rate adaptation in different scenarios, with the assumption of perfect channel knowledge and round robin scheduler.
  • Figs. 5 and 6 show the system performance of a group of seven cells in OFDM downlink with SISO (Simple Input Simple Output) and 8OW transmitted power in 20MHz bandwidth, the 5 th percentile user throughput at cell edge and the average cell throughput of RR (Radio Resource) scheduler and uniform PA (Power Adaptation) is shown in Fig. 5 and Fig. 6 respectively.
  • the continuous code-rate adaptation outperforms the discrete one significantly for different link adaptation schemes. Comparing to the discrete coding rate adaptation, the cell throughput increases around 12%, and to reach 0.65Mbps user throughput at cell edge, the continuous coding rate adaptation extends the coverage to nearly 300% of the discrete one. It is also interesting to see that the frequency domain modulation adaptation only brings up to 3% cell throughput gain and almost no gain or even slight loss in the user throughput at cell edge.

Landscapes

  • Engineering & Computer Science (AREA)
  • Quality & Reliability (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

Station mobile (UE), station de base (BS) et procédé destinés à un procédé pour une signalisation d'adaptation de liaison dans un réseau de communication sans fil comprenant au moins un émetteur et au moins un récepteur, comprenant les étapes consistant à déterminer des paramètres de qualité de canal au niveau du récepteur ; à attribuer, sur la base des paramètres de qualité de canal déterminés, des ressources radio pour au moins un utilisateur dans le réseau de communication sans fil ; à sélectionner un type de codage et de modulation à partir des candidats de modulation de codage disponibles pour les données d'utilisateur afin de remplir totalement la ressource radio attribuée ; à informer le récepteur du mode de modulation utilisé sur les données d'utilisateur ; à informer en outre le récepteur de la taille d'un paquet de données de base avant le codage des données d'utilisateur ; et à coder et moduler lesdites données d'utilisateur en fonction des candidats de codage et de modulation sélectionnés.
PCT/EP2006/008435 2006-08-29 2006-08-29 Procédé et agencement pour une signalisation d'adaptation de liaison dans un réseau de communication sans fil WO2008025366A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
PCT/EP2006/008435 WO2008025366A1 (fr) 2006-08-29 2006-08-29 Procédé et agencement pour une signalisation d'adaptation de liaison dans un réseau de communication sans fil
TW096122122A TW200816754A (en) 2006-08-29 2007-06-20 Method and arrangement for link adaption signalling in a wireless communication network

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/EP2006/008435 WO2008025366A1 (fr) 2006-08-29 2006-08-29 Procédé et agencement pour une signalisation d'adaptation de liaison dans un réseau de communication sans fil

Publications (1)

Publication Number Publication Date
WO2008025366A1 true WO2008025366A1 (fr) 2008-03-06

Family

ID=37985746

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2006/008435 WO2008025366A1 (fr) 2006-08-29 2006-08-29 Procédé et agencement pour une signalisation d'adaptation de liaison dans un réseau de communication sans fil

Country Status (2)

Country Link
TW (1) TW200816754A (fr)
WO (1) WO2008025366A1 (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2009035382A1 (fr) * 2007-09-11 2009-03-19 Telefonaktiebolaget Lm Ericsson (Publ) Ajustement d'indicateur de qualité de canal (cqi) pour des algorithmes de sélection de format de transport arbitraire
WO2010106330A3 (fr) * 2009-03-20 2011-03-24 Imperial Innovations Limited Procédé et appareil de chargement binaire pour une communication par canaux parallèles multicodes
WO2011110737A1 (fr) * 2010-03-08 2011-09-15 Nokia Corporation Sélection d'un format de codage pour des canaux communs dans des réseaux de communication cellulaire
WO2017187236A1 (fr) * 2016-04-29 2017-11-02 Telefonaktiebolaget Lm Ericsson (Publ) Réglage de limite de débit du code maximal spécifique à un dispositif sans fil
WO2017181046A3 (fr) * 2016-04-15 2017-12-21 Qualcomm Incorporated Techniques d'adaptation de débit ofdma

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003001681A2 (fr) * 2001-06-25 2003-01-03 Nokia Corporation Optimisation de mcs et multicode comportant une signalisation tfci
WO2004042982A2 (fr) * 2002-11-01 2004-05-21 Interdigital Technology Corporation Procede de prediction de la qualite de la voie dans des systemes de communications sans fil
EP1564953A2 (fr) * 2004-02-14 2005-08-17 Samsung Electronics Co., Ltd. Procédé de rétroaction d'information de l'état du canal pour un système de communication de plusieurs porteuses

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003001681A2 (fr) * 2001-06-25 2003-01-03 Nokia Corporation Optimisation de mcs et multicode comportant une signalisation tfci
WO2004042982A2 (fr) * 2002-11-01 2004-05-21 Interdigital Technology Corporation Procede de prediction de la qualite de la voie dans des systemes de communications sans fil
EP1564953A2 (fr) * 2004-02-14 2005-08-17 Samsung Electronics Co., Ltd. Procédé de rétroaction d'information de l'état du canal pour un système de communication de plusieurs porteuses

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
3GPP: "Physical Layer Aspects for Evolved UTRA TR 25.814", 3RD GENERATION PARTNERSHIP PROJECT (3GPP); TECHNICAL REPORT (TR), XX, XX, vol. 123, no. 25814, 1 May 2006 (2006-05-01), pages 20 - 42, XP002408008 *
ERICSSON: "Link Adaption for E-UTRA Downlink", TSG RAN WG1 LTE ADHOC MEETING, R1-060101, 23 January 2006 (2006-01-23) - 25 January 2006 (2006-01-25), pages 1 - 3, XP002432669, Retrieved from the Internet <URL:http://www.3gpp.org/ftp/tsg_ran/WG1_RL1/TSGR1_AH/LTE_AH_January-06/Docs/> [retrieved on 20070508] *
SAMSUNG: "Adaptive modulation and channel coding rate", 3GPP TSG RAN WG1 LTEADHOC MEETING, R1-060076, 23 January 2006 (2006-01-23) - 25 January 2006 (2006-01-25), pages 1 - 6, XP002432670, Retrieved from the Internet <URL:http://www.3gpp.org/ftp/tsg_ran/WG1_RL1/TSGR1_AH/LTE_AH_January-06/Docs/> [retrieved on 20070508] *

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2009035382A1 (fr) * 2007-09-11 2009-03-19 Telefonaktiebolaget Lm Ericsson (Publ) Ajustement d'indicateur de qualité de canal (cqi) pour des algorithmes de sélection de format de transport arbitraire
US8848550B2 (en) 2007-09-11 2014-09-30 Telefonaktiebolaget Lm Ericsson (Publ) CQI adjustment for arbitrary transport format selection algorithms
WO2010106330A3 (fr) * 2009-03-20 2011-03-24 Imperial Innovations Limited Procédé et appareil de chargement binaire pour une communication par canaux parallèles multicodes
WO2011110737A1 (fr) * 2010-03-08 2011-09-15 Nokia Corporation Sélection d'un format de codage pour des canaux communs dans des réseaux de communication cellulaire
CN102812657A (zh) * 2010-03-08 2012-12-05 诺基亚公司 选择蜂窝通信网络中用于公共信道的编码格式
US8452301B2 (en) 2010-03-08 2013-05-28 Nokia Corporation Method and apparatus for selecting a coding format
WO2017181046A3 (fr) * 2016-04-15 2017-12-21 Qualcomm Incorporated Techniques d'adaptation de débit ofdma
WO2017187236A1 (fr) * 2016-04-29 2017-11-02 Telefonaktiebolaget Lm Ericsson (Publ) Réglage de limite de débit du code maximal spécifique à un dispositif sans fil
US11075711B2 (en) 2016-04-29 2021-07-27 Telefonaktiebolaget Lm Ericsson (Publ) Wireless device specific maximum code rate limit adjustment

Also Published As

Publication number Publication date
TW200816754A (en) 2008-04-01

Similar Documents

Publication Publication Date Title
US10887150B2 (en) Method and apparatus for data transmission in a multiuser downlink cellular system
EP2135398B1 (fr) Procédé et appareil permettant une transmission dans un système de communication multiporteuse
US9985743B2 (en) Channel quality indicator for time, frequency and spatial channel in terrestrial radio access network
CN1943152B (zh) 用于具有自适应发射和反馈的多载波通信系统的方法和设备
US9025430B2 (en) System and method of modulation and coding scheme adjustment for a LTE shared data channel
AU2006234022B8 (en) Transmitting apparatus and transmitting method
US20090213802A1 (en) Base station, communication terminal, transmission method, and reception method
KR101742704B1 (ko) 무선 시스템의 상향링크 제어 신호 설계
AU2006204242A1 (en) Apparatus and method for transmitting/receiving channel quality information in a communication system
EP2213031B1 (fr) Signalement d&#39;informations de qualité de canal
KR100959742B1 (ko) 제어 채널 정보 전송 방법, 및 이를 이용한 기지국 및 단말기
WO2008025366A1 (fr) Procédé et agencement pour une signalisation d&#39;adaptation de liaison dans un réseau de communication sans fil
JP2009273183A (ja) 送信装置及び送信方法
Su et al. A hierarchical selective CQI feedback scheme for 3GPP long-term evolution system
KR101433847B1 (ko) 광대역 무선통신시스템에서 버스트 스케줄링 장치 및 방법
MX2007011897A (es) Aparato de transmision y metodo de transmision.

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 06791708

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

NENP Non-entry into the national phase

Ref country code: RU

122 Ep: pct application non-entry in european phase

Ref document number: 06791708

Country of ref document: EP

Kind code of ref document: A1

点击 这是indexloc提供的php浏览器服务，不要输入任何密码和下载