WO2018018579A1

WO2018018579A1 - Vector-based demodulation apparatus and demodulation method

Info

Publication number: WO2018018579A1
Application number: PCT/CN2016/092221
Authority: WO
Inventors: 张科峰
Original assignee: 武汉芯泰科技有限公司
Priority date: 2016-07-29
Filing date: 2016-07-29
Publication date: 2018-02-01

Abstract

Disclosed are a vector-based demodulation apparatus and demodulation method. The vector-based demodulation apparatus comprises a configuration unit for receiving user configuration information, so as to map a digital signal into a corresponding vector signal; and a table lookup unit for storing the digital signal, the corresponding vector signal and the mapping relationship therebetween in the form of a lookup table, and further for searching for the lookup table according to the input digital signal and outputting the corresponding vector signal. In the present application, a signal modulation method is made configurable by means of a configuration unit and a table lookup unit; in addition, a digital signal is mapped into a vector signal, so that phase modulation and amplitude modulation can be implemented at the same time. Therefore, the modulation method of the present application is compatible with any existing modulation method, comprising rectangular QAM, heart-shaped QAM, PSK, ASK, etc.

Description

Vector-based demodulation device and demodulation method

[0001] The present invention relates to the field of demodulation technologies, and in particular, to a vector-based demodulation device and a demodulation method.

Background technique

[0002] Demodulation is the process of recovering a message from a modulated signal carrying a message. In various information transmission or processing systems, the transmitting end modulates the carrier with the message to be transmitted to generate a signal carrying the message, and the receiving end must recover the transmitted message in order to utilize it. Demodulation is the inverse of modulation. The modulation method is different and the demodulation method is different. Corresponding to the classification of modulation, demodulation can be divided into sine wave demodulation and pulse wave demodulation. Sine wave demodulation can be further divided into amplitude demodulation, frequency demodulation and phase demodulation. In addition, there are some variants such as single sideband signal demodulation and vestigial sideband signal demodulation. Similarly, pulse wave demodulation can be divided into pulse amplitude demodulation, pulse phase demodulation, pulse width demodulation, and pulse code demodulation. Multiple modulation is required for multiple modulation. Since the digital baseband signal can only take discrete finite values, the corresponding carrier parameters can only take discrete finite values. The modulated signal can be regarded as the result of switching the carrier of different parameters by the digital baseband signal. This implementation method is called keying method. Therefore, the above three basic digital modulation methods are generally referred to as ASK (Amplitude Shift Keying), FSK (Frequency Shift Keying), and PSK (Phase Shift Keying). Based on the basic digital modulation method, QAM (Quadrature Amplitude Modulation) is derived, which is essentially a hybrid modulation of ASK and PSK.

In the prior art, no matter which modulation method is used, the method of mapping from digital signals to modulation symbols is fixed, cannot be programmed, and is incompatible with each other. Accordingly, the demodulation methods corresponding to the modulation method are also not programmable and are not compatible with each other. In the existing modulation technology, the relative positions between the constellation points in the constellation diagram are fixed, not programmable, and the constellation points cannot be randomly selected according to actual needs. Correspondingly, in the demodulation technique, the relative positions between constellation points in the constellation diagram are fixed, not programmable, and the constellation points cannot be randomly selected according to actual needs.

technical problem

In the prior art, regardless of the modulation method, the method of mapping from digital signals to modulation symbols is fixed, cannot be programmed, and is incompatible with each other. Correspondingly, the demodulation corresponding to the modulation mode The way is also not programmable, and it is not compatible with each other. In the existing modulation technology, the relative positions between the constellation points in the constellation diagram are fixed, not programmable, and the constellation points cannot be randomly selected according to actual needs. Correspondingly, in the demodulation technique, the relative positions between constellation points in the constellation diagram are fixed, not programmable, and the constellation points cannot be randomly selected according to actual needs.

Problem solution

Technical solution

[0005] In view of the defects in the prior art that various demodulation methods are not compatible with each other and are not programmable, the present invention provides a vector-based demodulation apparatus and a demodulation method.

[0006] The technical solution proposed by the present invention with respect to the above technical problems is as follows:

In one aspect, a vector-based demodulation apparatus is provided, including:

[0008] a lookup table unit for storing a vector signal, a digital signal corresponding to the vector signal, and a mapping relationship thereof in the form of a lookup table;

And a comparing unit, configured to compare the input vector signal with a vector signal stored in the lookup table unit, and the lookup table unit outputs a corresponding digital signal according to the comparison result of the comparing unit.

[0010] Preferably, the vector signal is any vector signal in any quadrant of the constellation diagram, and is different in the constellation diagram.

[0011] Preferably, in the constellation diagram, the vector signals are independent of each other.

[0012] Preferably, the lookup table unit is a register.

[0013] In another aspect, a vector-based demodulation method is provided, including the following steps:

[0014] Sl, storing a vector signal, a corresponding digital signal, and a mapping relationship thereof in the form of a lookup table;

[0015] S2, comparing the input vector signal with a vector signal stored in the lookup table unit, and outputting a corresponding digital signal according to the comparison result of the comparison unit.

[0016] Preferably, the vector signal is any vector signal in any quadrant of the constellation diagram, and is different in the constellation diagram.

[0017] Preferably, in the constellation diagram, the vector signals are independent of each other.

[0018] Preferably, the lookup table is stored in a register.

Advantageous effects of the invention

Beneficial effect The embodiments of the present invention have the following beneficial effects: The present application makes the demodulation mode of the signal compatible with any existing demodulation modes through the comparison unit and the lookup table unit, including rectangular QAM, heart-shaped QAM, PS K, and ASK and so on. Moreover, the demodulation method of the present application is vector-based, and has the functions of amplitude modulation and phase modulation.

Brief description of the drawing

DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings to be used in the embodiments or the prior art description will be briefly described below, and obviously, in the following description The drawings are only some of the embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative work.

1 is a block diagram of a typical communication system according to an embodiment of the present invention;

2 is a schematic structural view of the demodulation device shown in FIG. 1;

3 is a flow chart of a demodulation method provided by the present invention;

4a and 4b are schematic diagrams showing the structure of a constellation diagram provided by an embodiment of the present invention.

Embodiments of the invention

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. example. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

[0026] 诵信系统

1 is a typical block diagram of a communication system according to an embodiment of the present invention. The communication system 100 includes: a source encoding device 102, a channel encoding device 104, a modulating device 106, a channel 108, a demodulating device 110, a channel decrypting device 112, and a source encoding device 114. The source encoder 102 is configured to receive the source 151 to be transmitted. The source coding apparatus 102 is for encoding the source 151 and generating a source coded signal 152. Channel coding means 104 is operative to channel encode source coded signal 152 and to generate channel coded signal 153. Modulation means 106 is operative to modulate encoded signal 153 into signal 154 to be transmitted.

[0028] The to-be-transmitted signal 154 provides a receive signal 155 to the receiving end over the channel 108. The channel 108 includes but not Limited to microwave radio links, satellite channels, fiber optic cables, composite fiber optic cable systems, or copper cables. The channel 108 includes a propagation medium that can introduce interference and distortion into the signal 154 to be transmitted such that the received signal 155 is different from the signal 154 to be transmitted. Interference and distortion include, but are not limited to, noise, attenuation, phase shift changes, etc.

[0029] The demodulation device 110 is configured to demodulate the received signal 155 into a demodulated signal 156. Channel decoding device 112 is operative to decode demodulated signal 156 into channel decoded signal 157. Source decoding device 114 is operative to further decode channel decode signal 157 into target signal 158. The target signal 158 is provided to one or more receiver user devices. The one or more receiver user devices include, but are not limited to, a personal computer, a digital terminal device, a telephone device, a personal digital assistant, a software application, or any other device that can transmit or receive data.

FIG. 2 is a schematic structural diagram of a demodulation apparatus according to an embodiment of the present invention. The demodulation device 110 includes: a comparison unit 202 and a lookup table unit 204. The lookup table unit 204 is for storing a vector signal, a digital signal corresponding to the vector signal, and a mapping relationship thereof in the form of a lookup table. The vector signal and the mapping relationship are stored in the form of a lookup table, so that the vector signal and the mapping relationship can be freely changed. Because the mapping relationships are stored in a table rather than being solidified, they can be updated later. In the communication system provided by the present invention, before or after the source 151 is transmitted to the target terminal, the digital signal, the vector signal and the mapping relationship stored in the modulation device 106 are transmitted to the modulation device 110, thereby modulating the device 110. The contents of its lookup table can be automatically updated accordingly. In one embodiment of the invention, the mapping between the digital signal and the vector signal is a one-to-one mapping.

The comparison unit 202 is for comparing the input vector signal 155 with the vector signal 2 51 stored in the lookup table unit 204, and the lookup table unit 204 outputs the corresponding digital signal 156 according to the comparison result 252 of the comparison unit 202.

[0033] In one embodiment of the invention, lookup table unit 204 may employ a variety of data lookup methods to quickly find vector signal 251 that matches input vector signal 155 for input into comparison unit 202. Thus, the number of comparisons by the comparing unit 202 can be greatly reduced, the working speed can be increased, and the power consumption can be reduced. The data search method adopted by the lookup table unit 202 includes: a sequential search method, a binary search method, a binary tree, and the like. In the embodiment of the present invention, if there is no vector signal identical to the input vector signal 155 in the lookup table unit 204, the vector signal closest to the input quantity signal 155 is selected as the input vector. The signal, and the digital signal 156 corresponding to the closest vector signal is used as the output of the lookup table unit 204.

In one embodiment of the invention, as shown in Figures 4a and 4b, the vector signals A1~A8 may be any vector signals in any quadrant of the constellation and are different in the constellation. As shown in Figure 4a, the vector signals Al~A8 can be selected from the same quadrant of the constellation. As shown in Figure 4b, the vector signals A1~A8 can also be selected from different quadrants of the constellation. However, whether it is from the same quadrant or from different quadrants, the vector signals A1~A8 are different in the constellation, so that the mapping between the digital signal and the vector signal is guaranteed to be one-to-one mapping.

In another embodiment provided by the present invention, as shown in FIGS. 4a and 4b, the vector signals A1 to A8 are independent of each other, and there is no dependency between the vector signals. The user can select each vector signal in a targeted manner. It should be understood that the user can individually configure each vector signal according to actual needs so that there is a certain relationship between them. Thus, when it is necessary to be compatible with existing modulation schemes, vector signals can be configured to meet existing modulation schemes.

[0036] In one embodiment provided by the present invention, lookup table unit 204 is a register. The input digital signal 153 can be the address signal of the register, and the vector signal 154 corresponding to the digital signal 154 can be stored in the register. When a specific address signal 153 is input, the register 204 automatically outputs the vector signal 154 stored in the address. The correspondence between the address signal and the vector signal can be configured by the configuration unit 202.

[0037] The present application enables the demodulation of signals by the comparison unit and the lookup table unit to be compatible with any existing demodulation modes, including rectangular QAM, heart-shaped QAM, PSK, and ASK. Moreover, the demodulation method of the present application is vector-based, and has the functions of amplitude modulation and phase modulation.

Demodulation method

[0039] This embodiment provides a vector-based demodulation method. As shown in FIG. 3, the vector-based demodulation method can be applied to a demodulation device as described above, and the method can include the following steps:

[0040] Sl, storing a vector signal, a corresponding digital signal, and a mapping relationship thereof in the form of a lookup table;

[0041] S2, comparing the input vector signal with a vector signal stored in the lookup table unit, and outputting a corresponding digital signal according to the comparison result of the comparison unit.

[0042] In one embodiment of the present invention, as shown in FIGS. 4a and 4b, the vector signals A1~A8 may be in the constellation diagram. Any vector signal in the image limit, and is different in the constellation. As shown in Figure 4a, the vector signals Al~A8 may be selected from the same quadrant of the constellation. As shown in Figure 4b, the vector signals A1~A8 can also be selected from different quadrants of the constellation. However, whether it is from the same quadrant or from different quadrants, the vector signals A1~A8 are different in the constellation, so that the mapping between the digital signal and the vector signal is guaranteed to be a one-to-one mapping.

[] [Table 1]

[0044] In one embodiment provided by the present invention, the lookup table is stored in a register. As shown in Table 1, the lookup table 1 includes the input vector signals A1 to A8, and the digital signals 000 to 111 (assuming the address signals are 3 bits) corresponding to the vector signals one by one. It should be understood that the number of bits of the address signal is only an example in this embodiment, and is not intended to limit the number of bits of the address signal. The number of bits of the address signal can be designed to satisfy any modulation method as needed. As shown in FIG. 2, when a specific vector signal 155 is input, the lookup table unit 204 will one or more of the vector signals A1 to A8 in the lookup table according to a certain search method. The input to comparator 202 compares with vector signal 155 and then outputs a corresponding digital signal 156 based on the comparison. For example, when the input vector signal 155 is the same as the vector signal A2 in the lookup table, the comparison unit 202 feeds back the comparison result 252 to the lookup table unit 204, and the lookup table unit 204 outputs the digital signal 000 corresponding to the vector signal A2. For another example, when the input vector signal 155 is different from the vector signals A1~A8 in the lookup table, but the distance from A5 is closest, the comparison unit 252 feeds back the comparison result to the lookup table unit 204, and then looks up the table unit 204 output. A digital signal 110 corresponding to vector signal A5.

[0045] The present application enables the demodulation of signals by the comparison unit and the lookup table unit to be compatible with any existing demodulation modes, including rectangular QAM, heart-shaped QAM, PSK, and ASK. Moreover, the demodulation method of the present application is vector-based, and has the functions of amplitude modulation and phase modulation.

[0046] It should be understood that in the above lookup table 1, the digital signal is a Gray code to reduce the bit error rate. Other binary codes may also be employed in other embodiments of the invention.

The above disclosure is only a preferred embodiment of the present invention, and of course, the scope of the present invention is not limited thereto, and those skilled in the art can understand all or part of the process of implementing the above embodiments, and Equivalent variations of the claims of the invention are still within the scope of the invention.

Claims

Claim

[Claim 1] A vector-based demodulation device, comprising:

a lookup table unit for storing a vector signal, a digital signal corresponding to the vector signal, and a mapping relationship thereof in the form of a lookup table;

And a comparing unit, configured to compare the input vector signal with a vector signal stored in the lookup table unit, and the lookup table unit outputs the corresponding digital signal according to the comparison result of the comparing unit.

[Claim 2] The vector-based demodulating apparatus according to claim 1, wherein the vector signal is an arbitrary vector signal in any quadrant of the constellation diagram, and is different in the constellation diagram.

[Claim 3] The vector-based demodulating device according to claim 2, wherein in the constellation diagram, the vector signals are independent of each other.

[Claim 4] The demodulation device according to claim 1, wherein the lookup table unit is

[Claim 5] A vector-based demodulation method, comprising the steps of:

51. Store a vector signal, a corresponding digital signal, and a mapping relationship thereof in the form of a lookup table;

52. Compare the input vector signal with a vector signal stored in the lookup table unit, and output a corresponding digital signal according to the comparison result of the comparison unit.

[Claim 6] The vector-based demodulation method according to claim 5, wherein the vector signal is any vector signal in any quadrant of the constellation diagram, and is different in the constellation diagram.

[Claim 7] The vector-based demodulation method according to claim 6, wherein in the constellation diagram, the vector signals are independent of each other.

[Claim 8] The vector-based demodulation method according to claim 5, wherein the lookup table is stored in a register.