WO2022178886A1

WO2022178886A1 - Codeword mapping method and device

Info

Publication number: WO2022178886A1
Application number: PCT/CN2021/078321
Authority: WO
Inventors: 韩昌浩; 吴世娟; 赵慧; 余政
Original assignee: 华为技术有限公司
Priority date: 2021-02-27
Filing date: 2021-02-27
Publication date: 2022-09-01
Also published as: CN116848826A

Abstract

The present application provides a codeword mapping method, for use in improving the coding performance and energy allocation fairness of a communication system jointly designed by a multi-system channel coding technology and a sparse code multiple access (SCMA) technology. The method comprises: obtaining a first mapping relationship of at least one user on at least two resource blocks (S301), determining a second mapping relationship of the at least one user on the at least two resource blocks (S302), and determining a third mapping relationship of the at least one user on the at least two resource blocks according to a peak-to-average power ratio corresponding to the second mapping relationship of the at least one user on the at least two resource blocks (S303). The first mapping relationship of each user on each resource block is composed of at least two correspondences, and each correspondence is a correspondence between an SCMA codeword and a multi-system channel encoding symbol. A criterion value is used for measuring the probability that the SCMA codeword is erroneously decoded and the multi-system channel encoding symbol is erroneously decoded. The peak-to-average power ratio is a peak-to-average power ratio after the energy of the SCMA codeword is superimposed on the at least two resource blocks.

Description

Codeword mapping method and device

technical field

The present application relates to the field of communications, and in particular, to a codeword mapping method and device.

Background technique

Sparse code division multiple access (SCMA) has the characteristics of high shaping gain, support for high-order modulation and high-overload transmission. Multi-ary channel coding technology is better than binary channel coding technology in decoding performance. The communication system can be designed by combining the multi-ary channel coding technology and the SCMA technology. Exemplarily, the interleaving process is performed on the SCMA codeword set on the resource block of the even-numbered user in the constellation diagram, so that the multi-ary channel coding symbols {00, 01, 10, 11} and the SCMA codeword {-x There are various mapping relationships between ₂ , -x ₁ , x ₁ , x ₂ }. For example, Figure 1 shows two different mapping relationships between multi-ary channel coding symbols and SCMA codewords. As shown in Figure 1, after the interleaving process, there are two arrangements of multi-ary channel coding symbols, such as arrangement one {01,00,11,10} and arrangement two {10,11,00,01} , the arrangement method two {10,11,00,01} moves the multi-level channel coding symbol 11 and the multi-level channel coding symbol 00 from the outside to the inside of the coordinate axis, and changes the power distribution method to make the energy distribution more fair. The peak to average power ratio (PAPR) can be reduced.

However, the above mapping relationship is designed based on the codeword energy allocation, ignoring the influence of the mapping relationship selection on the decoding performance, and only the mapping relationship designed based on the codeword energy allocation may result in a decrease in bit error performance.

SUMMARY OF THE INVENTION

The embodiments of the present application provide a codeword mapping method and apparatus, which can improve the decoding performance and the fairness of energy allocation in a communication system jointly designed by the multi-ary channel coding technology and the SCMA technology.

To achieve the above object, the application adopts the following technical solutions:

In a first aspect, a codeword mapping method is provided. The codeword mapping method includes: obtaining a first mapping relationship of at least one user on at least two resource blocks; determining a second mapping relationship of at least one user on at least two resource blocks; The peak-to-average power ratio corresponding to the second mapping relationship on the block determines the third mapping relationship of the at least one user on the at least two resource blocks.

Wherein, the first mapping relationship of each user on each resource block consists of at least two corresponding relationships, each of which is a corresponding relationship between sparse code division multiple access SCMA codewords and multi-ary channel coding symbols. The second mapping relationship of each user on each resource block consists of at least one corresponding relationship, and the at least one corresponding relationship is the corresponding relationship with the smallest corresponding criterion value among the at least two corresponding relationships. The criterion value is used to measure whether the SCMA codeword is Incorrect decoding and the possibility of incorrect decoding of multi-binary channel coded symbols. The third mapping relationship of each user on each resource block is a corresponding relationship, a corresponding relationship is one of at least one corresponding relationship, and the peak-to-average power ratio is the energy of the SCMA codeword superimposed on at least two resource blocks. Peak-to-average power ratio.

Based on the codeword mapping method described in the first aspect, a first mapping relationship of at least one user on at least two resource blocks is obtained, and the first mapping relationship of each user on each resource block is composed of at least two corresponding relationships , and each correspondence is the correspondence between sparse code division multiple access SCMA codewords and multi-ary channel coding symbols. Then, determine the second mapping relationship of the at least one user on the at least two resource blocks. Since the second mapping relationship is the one with the smallest corresponding criterion value among the at least two correspondences included in the first mapping relationship, the criterion value is It is used to measure the possibility that the SCMA codeword is decoded incorrectly and the multi-level channel coded symbol is incorrectly decoded. In this way, the mapping relationship is determined based on the bit error performance, which can reduce the bit error rate and improve the bit error performance. On the basis of improving the bit error performance, the peak-to-average power ratio of each user after the codeword energy on at least two resource blocks is superimposed is further determined, and the corresponding relationship is selected according to the peak-to-average power ratio, so that the power between the codewords can be guaranteed. fairness of distribution.

In a possible design, the multi-level channel coding symbol may include a first multi-level channel coding symbol and a second multi-level channel coding symbol, and the SCMA codeword may include the first SCMA codeword and the second SCMA code Character. The criterion value may be determined according to the Hamming distance and the Euclidean distance, and the Hamming distance is the number of bits with different values in the corresponding bits between the first multi-ary channel coding symbol and the second multi-ary channel coding symbol, The Euclidean distance is the geometrical distance in Euclidean space between the first SCMA codeword and the second SCMA codeword. The first multi-level channel coding symbol corresponds to the first SCMA codeword, the second multi-level channel coding symbol corresponds to the second SCMA codeword, the first SCMA codeword is the codeword currently to be decoded, and the second SCMA codeword Different from the first SCMA codeword.

In this way, the bit error performance of the corresponding relationship can be obtained according to the criterion value, and the corresponding relationship that optimizes the bit error performance can be selected, thereby reducing the bit error rate.

Optionally, the criterion value may include traversing and stacking the product of at least one Hamming distance and at least one corresponding metric criterion, where the metric criterion is determined according to the Euclidean distance.

In a possible design manner, at least two resource blocks may include a first resource block and a second resource block, and at least one user may include the first user. The above-mentioned determining the third mapping relationship of the at least one user on the at least two resource blocks according to the peak-to-average power ratio corresponding to the second mapping relationship of the at least one user on the at least two resource blocks may include: The second mapping relationship on a resource block and the second mapping relationship of the first user on the second resource block, obtain the peak-to-average power ratio, and map the second mapping relationship on the first resource block corresponding to the first peak-to-average power ratio The relationship and the second mapping relationship on the second resource block are respectively determined as the third mapping relationship of the first user on the first resource block and the third mapping relationship of the first user on the second resource block. The peak-to-average power ratio may include at least two peak-to-average power ratios, and the minimum value of the at least two peak-to-average power ratios is the first peak-to-average power ratio.

In this way, by determining the possibility that the first multi-level channel coded symbol is decoded into the second multi-level channel coded symbol and the first SCMA codeword is decoded into the second SCMA codeword, the bit error performance of the corresponding relationship can be obtained, thereby The corresponding relationship can be selected according to the bit error performance, which can improve the bit error performance.

In a possible design manner, the first aspect provides a codeword mapping method, which may further include: obtaining a basic SCMA codeword set according to a first Euclidean criterion, and obtaining a basic SCMA codeword set according to the basic SCMA codeword set and the second Euclidean criterion A collection of dimensional SCMA codewords. Wherein, the first Euclidean criterion may include maximizing the minimum Euclidean distance between SCMA codewords of one user on one resource block, the basic SCMA codeword set may include SCMA codewords of one user on one resource block, one-dimensional SCMA codewords The set of codewords may include SCMA codewords of at least one user on one resource block, and the second Euclidean criterion may include a minimum Euclidean distance sum maximization between SCMA codewords of at least two users on one resource block. In this way, the minimum Euclidean distance is maximized between the SCMA codewords in the obtained basic SCMA codeword set, and the minimum Euclidean distance and maximization between the SCMA codewords of at least two users on one resource block can reduce bit errors rate to further improve bit error performance.

In one possible design approach, the first Euclidean criterion can satisfy the following relation:

Among them, r ₁ represents the value of the SCMA codeword with the smallest modulus value in the basic SCMA codeword set,

represents the value of the SCMA codeword with the smallest modulus value in the basic SCMA codeword set obtained by the first Euclidean criterion,

Represents SCMA codeword

a multiple of the SCMA codeword r ₁ ,

Represents SCMA codeword

a multiple of the SCMA codeword r ₁ ,

represents the multiple between SCMA codeword _r2 and SCMA codeword _r1 obtained by the first Euclidean criterion,

represents the SCMA codeword obtained by the first Euclidean criterion

A multiple of the SCMA codeword r ₁ , i ₁ can range from 1 to

Integer between , i ₂ can range from 1 to

An integer between, M ₂ represents the modulation order of the SCMA codeword. In this way, the minimum Euclidean distance is maximized between the SCMA codewords in the basic SCMA codeword set obtained according to the first Euclidean criterion, which can reduce the bit error rate and improve the bit error performance.

In one possible design approach, the second Euclidean criterion can satisfy the following relation:

Among them, θ ₁ ^* represents the angle between the SCMA codeword set of the user whose sequence number is 1 and the basic SCMA codeword set obtained by the second Euclidean criterion, and θ ₁ represents the SCMA codeword set of the user whose sequence number is 1 and the basic SCMA codeword set initial angle between sets of codewords, j represents the imaginary part of the complex number,

Represents the codeword with sequence number m ₁ in the basic SCMA codeword set, m ₁ =1,2,...,M ₂ , d _f represents the number of users superimposed on a resource block, and the operator symbol |||| Take the modulo. In this way, the minimum Euclidean distance sum between the SCMA codewords of at least two users on one resource block can be maximized, the bit error rate can be reduced, and the bit error performance can be further improved.

In one possible design, the metric can satisfy the following relationship:

in,

is the metric criterion, m ₁ represents the sequence number of the first SCMA codeword,

represents the serial number of the second SCMA codeword, k represents the serial number of the resource block, u represents the serial number of the user, x _u,k (m ₁ ) represents the code word with the serial number m ₁ of the user u on the resource block k,

Indicates that the sequence number of user u on resource block k is

The codeword of , the operator symbol |||| means modulo. In this way, the likelihood of the first SCMA codeword being decoded into the second SCMA codeword can be determined.

In one possible design approach, the criterion value can satisfy the following relationship:

Among them, E _mapping is the criterion value, M ₂ represents the modulation order of the SCMA codeword, m ₁ is the sequence number of the first SCMA codeword,

is the sequence number of the second SCMA codeword,

is the Hamming distance, c ₁ is the first multi-ary channel coding symbol,

Code symbols for the second multi-ary channel. In this way, the corresponding relationship can be determined according to the criterion value, for example, the corresponding relationship with the smallest criterion value can be selected, so that the corresponding relationship that optimizes the bit error performance can be obtained, the bit error rate can be reduced, and the bit error performance can be improved.

In one possible design approach, the peak-to-average power ratio can satisfy the following relationship:

Among them, PAPR is the peak-to-average power ratio, M ₂ represents the modulation order of the SCMA codeword, Z represents the number of resource blocks occupied by a single user, and A _zm represents the modulus value of the SCMA codeword.

In this way, determine the peak-to-average power ratio after the codeword energy of each user on at least two resource blocks is superimposed, and determine the corresponding relationship according to the peak-to-average power ratio, such as selecting the corresponding relationship of the smallest peak-to-average power ratio, so as to ensure Fairness of power allocation among codewords.

In a second aspect, a codeword mapping apparatus is provided. The codeword mapping apparatus includes: a mapping module and a processing module. Wherein, the mapping module is configured to obtain the first mapping relationship of at least one user on at least two resource blocks. The processing module is configured to determine the second mapping relationship of the at least one user on the at least two resource blocks. The processing module is further configured to determine the third mapping relationship of the at least one user on the at least two resource blocks according to the peak-to-average power ratio corresponding to the second mapping relationship of the at least one user on the at least two resource blocks.

In a possible design manner, the criterion value may include traversing and stacking the product of at least one Hamming distance and at least one corresponding metric criterion, and the metric criterion is determined according to the Euclidean distance.

In a possible design manner, at least two resource blocks may include a first resource block and a second resource block, and at least one user may include the first user. The processing module is further configured to obtain the peak-to-average power ratio according to the second mapping relationship of the first user on the first resource block and the second mapping relationship of the first user on the second resource block. The peak-to-average power ratio may include at least two peak-to-average power ratios, and the minimum value of the at least two peak-to-average power ratios is the first peak-to-average power ratio. The processing module is further configured to respectively determine the second mapping relationship on the first resource block and the second mapping relationship on the second resource block corresponding to the first peak-to-average power ratio as the first user on the first resource block. and the third mapping relationship of the first user on the second resource block.

In a possible design manner, the mapping module is further configured to obtain the basic SCMA codeword set according to the first Euclidean criterion. The first Euclidean criterion may include maximizing the minimum Euclidean distance between SCMA codewords of one user on one resource block, and the basic SCMA codeword set may include SCMA codewords of one user on one resource block. The mapping module is further configured to obtain a one-dimensional SCMA codeword set according to the basic SCMA codeword set and the second Euclidean criterion. The one-dimensional SCMA codeword set may include SCMA codewords of at least one user on one resource block, and the second Euclidean criterion may include the minimum Euclidean distance and the maximum distance between the SCMA codewords of at least two users on one resource block. change.

Represents SCMA codeword

a multiple of the SCMA codeword r ₁ ,

Represents SCMA codeword

a multiple of the SCMA codeword r ₁ ,

represents the SCMA codeword obtained by the first Euclidean criterion

A multiple of the SCMA codeword r ₁ , i ₁ can range from 1 to

Integer between , i ₂ can range from 1 to

An integer between, M ₂ represents the modulation order of the SCMA codeword.

Represents the codeword with sequence number m ₁ in the basic SCMA codeword set, m ₁ =1,2,...,M ₂ , d _f represents the number of users superimposed on a resource block, and the operator symbol |||| Modulo, d _f represents the number of users superimposed on a resource block, and operator |||| represents the modulo.

In one possible design, the metric can satisfy the following relationship:

in,

Indicates that the sequence number of user u on resource block k is

The codeword of , the operator symbol |||| means modulo.

is the sequence number of the second SCMA codeword,

is the Hamming distance, c ₁ is the first multi-ary channel coding symbol,

Code symbols for the second multi-ary channel.

It should be noted that the mapping module and the processing module may be set separately, or may be integrated in one module, that is, the processing module. The present application does not specifically limit the specific implementation manners of the mapping module and the processing module.

Optionally, the codeword mapping apparatus described in the second aspect may further include a transceiver module. The transceiver module is used to receive data and/or signaling sent by other devices, and may also be used to send data and/or signaling to other devices. Further, the transceiver module may include a receiving module and a sending module. The receiving module is used to receive data and/or signaling sent by other devices, and the sending module is used to send data and/or signaling to other devices. This application does not specifically limit the specific implementation manner of the transceiver module.

Optionally, the codeword mapping apparatus described in the second aspect may further include a storage module, where the storage module stores programs or instructions. When the processing module executes the program or the instruction, the codeword mapping apparatus described in the second aspect can execute the codeword mapping method described in the first aspect.

It should be noted that the codeword mapping apparatus described in the second aspect may be a terminal device, or may be a chip (system) or other components or components that can be provided in the terminal device, which is not limited in this application.

In addition, for the technical effect of the codeword mapping apparatus described in the second aspect, reference may be made to the technical effect of the codeword mapping method described in any possible implementation manner in the first aspect, which will not be repeated here.

In a third aspect, a codeword mapping apparatus is provided. The codeword mapping apparatus includes a processor coupled to a memory for storing a computer program. The processor is configured to execute the computer program stored in the memory, so that the codeword mapping apparatus executes the codeword mapping method described in any possible implementation manner of the first aspect.

In a possible design, the codeword mapping apparatus described in the third aspect may further include a transceiver. The transceiver may be a transceiver circuit or an input/output port. The transceiver may be used for the codeword mapping apparatus to communicate with other devices.

In this application, the codeword mapping apparatus described in the third aspect may be a terminal device, or a chip or a chip system provided inside the terminal device.

For the technical effect of the codeword mapping apparatus described in the third aspect, reference may be made to the technical effect of the codeword mapping method described in any implementation manner in the first aspect, which will not be repeated here.

In a fourth aspect, a chip system is provided, the chip system includes a processor and an input/output port, the processor is used to implement the processing functions involved in the first aspect, and the input/output port is used to implement the first aspect The transceiver functions involved.

In a possible design, the chip system further includes a memory for storing program instructions and data for implementing the functions involved in the first aspect.

The chip system may be composed of chips, or may include chips and other discrete devices.

In a fifth aspect, a computer-readable storage medium is provided, comprising: a computer program or instruction; when the computer program or instruction is run on a computer, the computer is made to execute any one of the possible implementations described in the first aspect Codeword mapping method.

In a sixth aspect, a computer program product is provided, comprising a computer program or an instruction, which, when the computer program or instruction is run on a computer, causes the computer to execute the codeword mapping described in any possible implementation manner in the first aspect method.

Description of drawings

1 is a schematic diagram of the mapping relationship between a multi-ary channel coding symbol and an SCMA codeword provided by an embodiment of the present application;

2 is a schematic structural diagram of a codeword mapping apparatus provided by an embodiment of the present application;

3 is a schematic flowchart of a codeword mapping method provided by an embodiment of the present application;

FIG. 4 is a schematic diagram of Polar code encoding provided by an embodiment of the present application;

FIG. 5 is a schematic structural diagram of another codeword mapping apparatus provided by an embodiment of the present application.

Detailed ways

The technical solutions in the present application will be described below with reference to the accompanying drawings.

The technical solutions of the embodiments of the present application can be applied to various communication systems, such as a wireless fidelity (WiFi) system, a vehicle-to-everything (V2X) communication system, a device-to-device (device-to-device, D2D) communication system, Internet of Vehicles communication system, 4th generation (4G) mobile communication system, such as long term evolution (LTE) system, worldwide interoperability for microwave access (WiMAX) communication systems, 5th generation (5G) mobile communication systems, such as new radio (NR) systems, and future communication systems, such as 6th generation (6G) mobile communication systems. It should be noted that the solutions in the embodiments of the present application may also be applied to other communication systems, and the corresponding names may also be replaced by the names of corresponding functions in other communication systems.

This application will present various aspects, embodiments, or features around a system that may include a plurality of devices, components, modules, and the like. It is to be understood and appreciated that the various systems may include additional devices, components, modules, etc., and/or may not include all of the devices, components, modules, etc. discussed in connection with the figures. In addition, combinations of these schemes can also be used.

In addition, in the embodiments of the present application, words such as "exemplarily" and "for example" are used to represent examples, illustrations or illustrations. Any embodiment or design described in this application as "exemplary" should not be construed as preferred or advantageous over other embodiments or designs. Rather, the use of the word example is intended to present a concept in a concrete way.

In the embodiments of the present application, sometimes _a subscript such as M1 may be mistakenly written in a non-subscript form such as M1. When the difference is not emphasized, the meaning to be expressed is the same.

The codeword mapping method provided in the embodiment of the present application can be applied to a terminal device, where the terminal device is a terminal with a wireless transceiver function or a chip or a chip system that can be provided in the terminal. The terminal equipment may also be referred to as user equipment, access terminal, subscriber unit, subscriber station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent, or user equipment. The terminal device in the embodiment of the present application may be a mobile phone (mobile phone), a tablet computer (Pad), a computer with a wireless transceiver function, a virtual reality (virtual reality, VR) terminal device, an augmented reality (augmented reality, AR) terminal equipment, wireless terminals in industrial control, wireless terminals in self driving, wireless terminals in remote medical, wireless terminals in smart grid, transportation security ( Wireless terminals in transportation safety), wireless terminals in smart cities, wireless terminals in smart homes, vehicle-mounted terminals, RSUs with terminal functions, etc. The terminal device of the present application may also be an on-board module, on-board module, on-board component, on-board chip or on-board unit built into the vehicle as one or more components or units. The on-board component, on-board chip or on-board unit may implement the codeword mapping method provided in this application.

FIG. 2 is a schematic structural diagram of a codeword mapping apparatus 200 that can be used to execute the codeword mapping method provided by the embodiment of the present application. The codeword mapping apparatus 200 may be a terminal device, or may be a chip applied in the terminal device or other components with terminal functions.

As shown in FIG. 2 , the codeword mapping apparatus 200 may include a processor 201 and a memory 202 . Optionally, the codeword mapping apparatus 200 may further include a transceiver 203 . Wherein, the processor 201 is coupled with the memory 202 and the transceiver 203, such as can be connected through a communication bus.

Below in conjunction with FIG. 2, each constituent component of the codeword mapping apparatus 200 is specifically introduced:

The processor 201 is the control center of the codeword mapping apparatus 200, and may be a processor or a general term for multiple processing elements. For example, the processor 201 is one or more central processing units (central processing units, CPUs), may also be specific integrated circuits (application specific integrated circuits, ASICs), or is configured to implement one or more of the embodiments of the present application An integrated circuit, such as: one or more microprocessors (digital signal processor, DSP), or, one or more field programmable gate array (field programmable gate array, FPGA).

The processor 201 can execute various functions of the codeword mapping apparatus 200 by running or executing software programs stored in the memory 202 and calling data stored in the memory 202 .

In a specific implementation, as an embodiment, the processor 201 may include one or more CPUs, such as CPU0 and CPU1 shown in FIG. 2 .

In a specific implementation, as an embodiment, the codeword mapping apparatus 200 may also include multiple processors, for example, the processor 201 and the processor 204 shown in FIG. 2 . Each of these processors can be a single-core processor (single-CPU) or a multi-core processor (multi-CPU). A processor herein may refer to one or more communication devices, circuits, and/or processing cores for processing data (eg, computer program instructions).

The memory 202 may be read-only memory (ROM) or other type of static storage communication device that can store static information and instructions, random access memory (RAM) or other type of static storage communication device that can store information and instructions. Type of dynamic storage communication device, it can also be electrically erasable programmable read-only memory (electrically erasable programmable read-only memory, EEPROM), compact disc read-only memory (CD-ROM) or other optical disk storage, Optical disc storage (including compact discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage communication devices, or capable of carrying or storing desired program code in the form of instructions or data structures and Any other medium that can be accessed by a computer, but is not limited to this. The memory 202 can exist independently, or can be integrated with the processor 201 .

Wherein, the memory 202 is used for storing the software program for executing the solution of the present application, and the execution is controlled by the processor 201 . For the above specific implementation manner, reference may be made to the following method embodiments, which will not be repeated here.

The transceiver 203 is used for communication with other codeword mapping apparatuses. Of course, the transceiver 203 may also be used to communicate with a communication network. Transceiver 203 may include a receiver to implement a receive function, and a transmitter to implement a transmit function.

It should be noted that the structure of the codeword mapping apparatus 200 shown in FIG. 2 does not constitute a limitation on the codeword mapping apparatus, and the actual codeword mapping apparatus may include more or less components than those shown in the figure, or Combining certain components, or different component arrangements.

The codeword mapping method provided by the embodiment of the present application will be described in detail below with reference to FIG. 3 to FIG. 4 .

Exemplarily, FIG. 3 is a schematic flowchart of a codeword mapping method provided by an embodiment of the present application. The number of users J=6, the number of resource blocks K=4, the base number of channel coding M ₁ =4, and the modulation order of the SCMA codeword M ₂ =4 are used as examples for description.

As shown in Figure 3, the codeword mapping method includes the following steps:

S301: Obtain a first mapping relationship of at least one user on at least two resource blocks.

Exemplarily, the first mapping relationship of each user on each resource block consists of at least two corresponding relationships. That is, the first mapping relationship may include at least two corresponding relationships.

Exemplarily, each correspondence is a correspondence between sparse code division multiple access SCMA codewords and multi-ary channel coding symbols.

In this way, the corresponding relationship between SCMA codewords and multi-ary channel coding symbols can be designed for each SCMA codeword set in the factor matrix, and the factor matrix can include the SCMA codeword set of at least one user on at least two resource blocks .

In a possible design solution, the codeword mapping method provided by the embodiment of the present application may further include: obtaining a multi-ary channel coding symbol.

Optionally, before the above S301, the multi-ary channel coding symbols may be obtained.

Exemplarily, taking the Polar code as an example, the Polar code is encoded by the multi-system method, and the calculation field is GF(M ₁ ), where M ₁ represents the channel coding system number, and the coding kernel of the Polar code can satisfy the following: Formula 1).

In the above formula (1), G' represents the coding kernel of the Polar code, where α is an integer less than or equal to M ₁ -1, β is an integer less than or equal to M ₁ -1, and M ₁ represents the channel coding progress. system number.

Optionally, the encoding process may satisfy the following formula (2).

In the above formula (2), n _c =N/log ₂ M ₁ represents the number of symbols after converting binary channel coding symbols into multi-ary channel coding symbols, N represents the number of binary channel coding symbols, and M ₁ represents channel coding the base number,

represents a sequence of binary channel-coded symbols,

Represents a sequence of multi-binary channel-coded symbols, mathematical symbols

represents the Kronecker product.

Optionally, obtaining the multi-ary channel coding symbol above may include: designing a binary channel coding symbol with a code length of n _c *log ₂ M ₁

Convert binary channel-coded symbols to multi-binary channel-coded symbols with the number of symbols n _c

Encodes multi-binary channel coded symbols.

Exemplarily, FIG. 4 is a schematic diagram of encoding a quaternary Polar code with four symbols. Among them, u ₁ , . . . , u ₄ is the source sequence, which represents the Polar code input before encoding. x ₁ ,...,x ₄ represent coding sequences. c ₁ ,...,c ₄ is the output sequence, representing the Polar code obtained after encoding. W ₂ represents the channel obtained by combining two channels W, W ₄ represents the channel obtained by combining two channels W ₂ , mathematical notation

Represents modulo 2 plus.

In a possible design solution, the codeword mapping method provided by the embodiment of the present application may further include: obtaining an SCMA codeword set.

Optionally, the SCMA codeword set may be obtained before the above S301.

It should be noted that the embodiment of the present application does not limit the sequence of obtaining the multi-ary channel coding symbol and obtaining the SCMA codeword set.

In some embodiments, obtaining the SCMA codeword set above may include the following steps 1 to 2.

Step 1, obtain a basic SCMA codeword set according to the first Euclidean criterion.

Optionally, the first Euclidean criterion may include maximizing the minimum Euclidean distance between SCMA codewords of a user on a resource block. In this way, the minimum Euclidean distance maximization is satisfied between the SCMA codewords in the obtained basic SCMA codeword set.

Optionally, the base SCMA codeword set may include one user's SCMA codeword on one resource block.

Exemplarily, SCMA codewords of d _f users on one resource block constitute a complex number set _Sk,u . Among them, K represents the number of resource blocks, k=1,2,...,K; u represents the user's serial number, u=0,1,...d _f -1; d _f means superimposed on a resource block the number of users. The complex number set S _k,u includes {S _k,0 ,S _k,1 ,...,S _k,df-1 }, and each subset includes M ₂ SCMA codewords.

Exemplarily, _Sk,0 may be referred to as a basic SCMA codeword set, and the elements included in the basic SCMA codeword set may be real numbers. The basic SCMA codeword set can be of the form:

in,

is the SCMA codeword in the base SCMA codeword set.

Optionally, the codeword mapping method provided by the embodiment of the present application may further include: rotating the basic SCMA codeword set _Sk,0 to obtain other SCMA codeword sets on the resource block where the basic SCMA codeword set is located. The set of sub-SCMA codewords other than the base SCMA codeword set in the complex number set _Sk,u may be referred to as the first SCMA codeword set. The first set of SCMA codewords includes SCMA codewords for one user on one resource block.

Exemplarily, the first SCMA codeword set may satisfy the following formula (3).

In the above formula (3), _{Sk, u+1} represents the first SCMA codeword set, u represents the serial number of the user, u=0, 1, . . . d _f -1, d _f represents on a resource block The number of superimposed users, j represents the imaginary part of the complex number, and θ _u represents the angle between the SCMA codeword set of user u on resource block k and the base SCMA codeword set. θ _u can be called the rotation angle.

Optionally,

Optionally, the basic SCMA codeword set obtained according to the first Euclidean criterion may satisfy the following formula (4).

In the above formula (4), Ω _basic is the first Euclidean criterion,

is the base SCMA codeword set obtained according to the first Euclidean criterion. That is, S _k,0 can be optimized according to the first Euclidean criterion to obtain

thereby

The minimum Euclidean distance is maximized between the SCMA codewords in .

Optionally, the first Euclidean criterion may satisfy the following formula (5).

In the above formula (5), r ₁ represents the value of the SCMA codeword with the smallest modulus value in the basic SCMA codeword set,

Represents SCMA codeword

a multiple of the SCMA codeword r ₁ ,

Represents SCMA codeword

a multiple of the SCMA codeword r ₁ ,

represents the SCMA codeword obtained by the first Euclidean criterion

A multiple of the SCMA codeword r ₁ , i ₁ can range from 1 to

Integer between , i ₂ can range from 1 to

An integer between, M ₂ represents the modulation order of the SCMA codeword.

Optionally, the relationship between the SCMA codewords in the SCMA codeword set satisfies the following formula (6).

|r _i+1 |=μ _i |r ₁ | (6)

In the above formula (6), the value of i ranges from 1 to

An integer between , and μ _i is a multiple representing the SCMA codeword r _i+1 and the SCMA codeword r ₁ .

Optionally, the average signal energy of each user on each resource block is 1, which can specifically satisfy the following formula (7), so as to ensure fairness and convenience in practical applications.

In the above formula (7), P _avg is the average signal energy, r _i is the SCMA codeword, and the value of i ranges from 1 to

An integer between, M ₂ represents the modulation order of the SCMA codeword.

Step 2: Obtain a one-dimensional SCMA codeword set according to the basic SCMA codeword set and the second Euclidean criterion.

Optionally, the one-dimensional SCMA codeword set may include SCMA codewords of at least one user on one resource block.

Taking the number of users superimposed on one resource block d _f =3, the number of resource blocks K=4, and the basic SCMA codeword set is the SCMA codeword set of one user among 3 users as an example, the above-mentioned step 2 is used as an example. method, the obtained one-dimensional SCMA codeword set may include SCMA codewords of 2 users on resource block 1. By performing the above step 2 multiple times, all sets of SCMA codewords in the factor matrix can be obtained. For example, according to the base SCMA codeword set on resource block 2 and the second Euclidean criterion, the obtained one-dimensional SCMA codeword set for resource block 2 may include SCMA codewords of 2 users on resource block 2. Similarly, using the method described in the above step 2, the obtained one-dimensional SCMA codeword set of resource block 3 may include SCMA codewords of 2 users on resource block 3 . Similarly, using the method described in the above step 2, the obtained one-dimensional SCMA codeword set of resource block 4 may include SCMA codewords of two users on resource block 4.

Optionally, the second Euclidean criterion may include a minimum Euclidean distance sum maximization between SCMA codewords of at least two users on one resource block.

Exemplarily, taking the number of users d _f =3 superimposed on one resource block and the number of resource blocks K=4 as an example, the SCMA codewords of the three users on the resource block 1 can be optimized according to the second Euclidean criterion, Maximize the minimum sum of Euclidean distances satisfied between the SCMA codewords of the 3 users on resource block 1. Similarly, the SCMA codewords for 3 users on resource block 2, the SCMA codewords for 3 users on resource block 3, and the SCMA codewords for 3 users on resource block 4 can be optimized according to the second Euclidean criterion , and will not be repeated here.

In some embodiments, the second step above may include: optimizing the rotation angle according to the basic SCMA codeword set and the second Euclidean criterion, and the optimized rotation angle may satisfy the following formula (8).

In the above formula (8), θ ₁ ^* represents the angle between the SCMA codeword set of the user whose sequence number is 1 obtained by the second Euclidean criterion and the basic SCMA codeword set,

represents the angle between the SCMA codeword set of the user whose sequence number is d _f -1 obtained by the second Euclidean criterion and the basic SCMA codeword set, θ ₁ represents the SCMA codeword set of the user whose sequence number is 1 and the basic SCMA codeword the initial angle between sets,

represents the initial angle between the SCMA codeword set of the user whose serial number is d _f -1 and the basic SCMA codeword set, and Ω _mother represents the second Euclidean criterion.

In this way, according to the above formula (8), the optimized rotation angles of d _f users can be obtained

u represents the serial number of the user, u=0, 1, . . . d _f -1, and d _f represents the number of users superimposed on one resource block.

In some embodiments, the above-mentioned step 2 may further include: obtaining a one-dimensional SCMA codeword set according to the angle between the SCMA codeword set of the user whose serial number is u obtained through the second Euclidean criterion and the basic SCMA codeword set.

In some embodiments, the second Euclidean criterion may satisfy the following formula (9).

In the above formula (9), θ ₁ ^* represents the angle between the SCMA codeword set of the user whose sequence number is 1 obtained by the second Euclidean criterion and the basic SCMA codeword set, and θ ₁ represents the SCMA codeword set of the user whose sequence number is 1 the initial angle between the set of codewords and the set of underlying SCMA codewords, j represents the imaginary part of the complex number,

Represents the codeword with sequence number m ₁ in the basic SCMA codeword set, m ₁ =1,2,...,M ₂ , d _f represents the number of users superimposed on a resource block, and the operator symbol |||| Take the modulo.

Exemplarily, a set of SCMA codewords other than the base SCMA codeword set on one resource block

with the underlying SCMA codeword set

The relationship between them satisfies the following formula (10).

In the above formula (10),

Represents the SCMA codeword set other than the basic SCMA codeword set on a resource block obtained by the second Euclidean criterion, u represents the sequence number of the user, u=0,1,...d _f -1, d _f represents in a The number of users superimposed on the resource block, j represents the imaginary part of the complex number,

represents the angle between the SCMA codeword (set) of user u on resource block k obtained according to the second Euclidean criterion and the base SCMA codeword set (or the SCMA codeword in the base SCMA codeword set).

Exemplarily, it is assumed that the SCMA codeword set of the user whose sequence number is (u+1) on one resource block

The SCMA codeword whose sequence number is m ₁ is

with the underlying SCMA codeword set

The SCMA codeword with sequence number m ₁ in

The relationship between them satisfies the following formula (11).

In the above formula (11), u represents the serial number of the user, u=0,1,...d _f -1, d _f represents the number of users superimposed on a resource block, j represents the imaginary part of the complex number,

represents the angle between the SCMA codeword (set) of user u on resource block k obtained according to the second Euclidean criterion and the base SCMA codeword set (or the SCMA codeword in the base SCMA codeword set). Alternatively, θ _u may be referred to as the rotation angle.

In this way, the above formula (10) is used to traverse

All SCMA codewords of d _f -1 users in the one-dimensional SCMA codeword set can be obtained.

Optionally, the codeword mapping method provided in the embodiment of the present application may further include: dividing the one-dimensional SCMA codeword set to at least one user on one resource block, and obtaining the basic SCMA codeword set on the one resource block except for the Set of SCMA codewords other than .

In this way, the one-dimensional SCMA codeword set is divided into d _f -1 users superimposed on the resource blocks corresponding to the one-dimensional SCMA codeword set, and a complex number set can be obtained.

set of complex numbers

include

The SCMA codebook (also referred to as an SCMA codeword set) obtained according to the above steps 1 and 2 is given as an example below. Exemplarily, it is assumed that the number of users J=6, the number of resource blocks K=4, the base number of channel coding M ₁ =4, the modulation order of the SCMA codeword, d _f =3, according to the above step 1 The basic SCMA codeword set obtained by the method is

The one-dimensional SCMA codeword set obtained according to the above step 2 includes:

in,

Table 1

Exemplarily, the representation of the factor matrix F is as follows:

set complex numbers

It is reused on 4 resource blocks and divided into d _f =3 users on the corresponding resource blocks respectively. Wherein, the SCMA codeword sets of the same user on different resource blocks are different.

Exemplarily, it is assumed that the basic constellation point sets on the four resource blocks are all the same, which are

Then, the set of codewords obtained in the above steps 1 and 2 may be as shown in Table 1 above. Alternatively, the obtained SCMA codebook can be expressed in the form of a factor matrix F.

In other embodiments, obtaining the SCMA codeword set above may include: obtaining an SCMA codebook based on a Cartesian product-based codebook design method.

Table 2

Illustratively, the set of SCMA codewords for 4-QAM is used to generate the set of mother SCMA codewords.

Specifically, firstly, two K-dimensional SCMA codeword sets (also called constellation diagrams) are subjected to phase rotation respectively, and then the Cartesian product of the two rotated 4-QAM SCMA codeword sets is performed to obtain the mother SCMA code Word set, based on the mother SCMA codeword set and the mapping matrix to obtain the SCMA codebook.

Exemplarily, the mapping matrix F' can satisfy the following relationship:

Taking the number of users J=6, the number of resource blocks K=4, the number of resource blocks occupied by a single user Z=2, d _f =3, as an example, the SCMA codebook obtained by the codebook design method based on the Cartesian product can be As shown in Table 2 above.

S302: Determine a second mapping relationship of at least one user on at least two resource blocks.

Exemplarily, the second mapping relationship of each user on each resource block consists of at least one corresponding relationship. That is, the second mapping relationship may include one or more corresponding relationships.

Exemplarily, the at least one correspondence is the correspondence with the smallest corresponding criterion value among the at least two correspondences. That is to say, the second mapping relationship is the corresponding relationship with the smallest corresponding criterion value among the at least two corresponding relationships included in the first mapping relationship.

Exemplarily, the criterion value is used to measure the probability of incorrect decoding of SCMA codewords and incorrect decoding of multi-binary channel coded symbols. In this way, the mapping relationship is determined based on the bit error performance, and the corresponding relationship with the smallest criterion value can be selected, so that the corresponding relationship that optimizes the bit error performance can be obtained, the bit error rate can be reduced, and the bit error performance can be improved.

Optionally, the criterion value may be used to select the mapping relationship for each SCMA codeword set in the factor matrix F.

Illustratively, take the SCMA codeword set S _1,0 in the factor matrix F as an example. As shown in Table 3 below, it is assumed that the first mapping relationship includes 24 correspondences, of which the criterion value of 8 correspondences is -48, the criterion value of 8 correspondences is -44.8, and the criterion value of the other 8 correspondences is -35.2. The criterion value-48 is the smallest among the criterion value-48, criterion value-44.8 and criterion value-35.2, so it is determined that the second mapping relationship of the SCMA codeword set S _1,0 includes 8 correspondences corresponding to criterion value-48. Similarly, a similar method can be used to obtain the second mapping relationship of other SCMA codeword sets (eg S _3,2 ) in the factor matrix F. It is assumed that the obtained second mapping relationship of the SCMA codeword set S _3,2 also includes 8 corresponding relationships.

table 3

准则值guideline value	映射关系的数量number of mappings
-48-48	88
-44.8-44.8	88
-35.2-35.2	88

In some embodiments, the multi-ary channel coded symbols may include first and second multi-ary channel coded symbols.

Exemplarily, the multi-ary channel coded symbol may include a plurality of multi-ary coded symbols, and the plurality of multi-ary coded symbols include a first multi-ary channel coded symbol and a second multi-ary channel coded symbol.

Optionally, the SCMA codeword may include a first SCMA codeword and a second SCMA codeword. Illustratively, the SCMA codeword may include a plurality of SCMA codewords including a first SCMA codeword and a second SCMA codeword.

Specifically, the first multi-level channel coding symbol corresponds to the first SCMA code word, the second multi-level channel coding symbol corresponds to the second SCMA code word, the first SCMA code word is the code word to be decoded currently, and the second The SCMA codeword is different from the first SCMA codeword.

Exemplarily, the criterion value may be determined according to the Hamming distance and the Euclidean distance.

Exemplarily, the Hamming distance is the number of bits with different values among the corresponding bits between the first multi-ary channel coding symbol and the second multi-ary channel coding symbol.

Exemplarily, the Euclidean distance is the Euclidean spatial geometric distance between the first SCMA codeword and the second SCMA codeword.

In this way, by determining the possibility that the first multi-level channel coded symbol is decoded into the second multi-level channel coded symbol and the first SCMA codeword is decoded into the second SCMA codeword, the bit error performance of the corresponding relationship can be obtained by selecting The corresponding relationship to optimize the bit error performance, thereby reducing the bit error rate.

In some embodiments, the criterion value includes traversing the product of at least one Hamming distance and at least one corresponding metric criterion, and the metric criterion may be determined according to the Euclidean distance.

Exemplarily, the metric can satisfy the following relationship in the following formula (12).

In the above formula (12),

Indicates that the sequence number of user u on resource block k is

The codeword of , the operator symbol |||| means modulo.

Exemplarily, the criterion value may satisfy the following formula (13).

In the above formula (13), E _mapping is the criterion value, M ₂ represents the modulation order of the SCMA codeword, m ₁ is the serial number of the first SCMA codeword,

is the sequence number of the second SCMA codeword,

is the Hamming distance, c ₁ is the first multi-ary channel coding symbol,

Code symbols for the second multi-ary channel.

In a possible design solution, the metric can be obtained based on the Max-log MPA decoding algorithm. Max-Log MPA algorithm does not need exponential operation to calculate absolute probability value in the process of calculating conditional probability.

Optionally, the Max-log MPA decoding algorithm is approximated by the Jacobian formula, and obtaining the Max-Log MPA algorithm includes initializing the user data prior probability and calculating the conditional probability.

Exemplarily, the prior probability may satisfy the following formula (14).

In the above formula (14), taking d _f =3 as an example, m ₁ represents the sequence number of the SCMA codeword of user 1 on resource block k, m ₁ =1,2,...M ₂ . m ₂ represents the sequence number of the SCMA codeword of user 2 on resource block k, m ₂ =1,2,...M ₂ . m ₃ represents the sequence number of the SCMA codeword of user 3 on resource block k, m ₃ =1,2,...M ₂ . k represents the sequence number of the resource block, k=1, 2, . . . K. h _k,j represents the channel coefficient of user j on resource block k, x _j,k represents the SCMA codeword of user j on resource block k, y _k represents the received signal on resource block k at the receiver, n _k represents Received noise on resource block k.

The initialization information in the above formula (14) will affect the final SCMA codeword decision result of the user. For example, the order of x _1,k (m ₁ ) of SCMA codewords will affect the confidence information size relationship of each SCMA codeword, thereby affecting the probability that different SCMA codewords are erroneously judged as other codewords. And the order of x _1,k (m ₁ ) of the SCMA codeword will affect the correspondence between the M ₂ -order SCMA codeword and log(M ₂ )/log(M ₁ ) M ₁ -ary channel coding symbols. Affects the Hamming distance between log(M ₂ )/log(M ₁ ) M ₁ -ary channel coding symbols, thereby affecting the final bit error rate.

Exemplarily, the following formula (15) is obtained by analyzing the received signal _yk .

In the above formula (15), taking d _f =3 as an example, m _1,y represents the received codeword of user 1 on resource block k, and m _2,y represents the received codeword of user 2 on resource block k , m _3,y represents the received codeword of user 3 on resource block k. In this way, the measurement criterion can be obtained according to the above formula (15), and the above formula (12) can be obtained.

S303: Determine a third mapping relationship of the at least one user on the at least two resource blocks according to the peak-to-average power ratio corresponding to the second mapping relationship of the at least one user on the at least two resource blocks.

Exemplarily, the third mapping relationship of each user on each resource block is one corresponding relationship, and one corresponding relationship is one of at least one corresponding relationship. That is, the third mapping relationship is one of the at least one corresponding relationship included in the second mapping relationship.

Exemplarily, the peak-to-average power ratio is the peak-to-average power ratio after the energy of the SCMA codeword is superimposed on at least two resource blocks.

Optionally, the at least two resource blocks include a first resource block and a second resource block, and the at least one user includes the first user.

In some embodiments, the above S303 may include the following steps 3 to 4.

Step 3: Obtain the peak-to-average power ratio according to the second mapping relationship of the first user on the first resource block and the second mapping relationship of the first user on the second resource block.

Optionally, the peak-to-average power ratio may include at least two peak-to-average power ratios, and the minimum value of the at least two peak-to-average power ratios is the first peak-to-average power ratio.

Step 4, respectively determine the second mapping relationship on the first resource block and the second mapping relationship on the second resource block corresponding to the first peak-to-average power ratio as the first user's second mapping relationship on the first resource block. The three mapping relationships and the third mapping relationship of the first user on the second resource block. That is to say, the third mapping relationship may be a corresponding relationship corresponding to the smallest peak-to-average power ratio.

Exemplarily, it is assumed that in the above S302, the obtained second mapping relationship of user J ₁ on resource block 1 includes 8 corresponding relationships (eg, corresponding relationship 1-corresponding relationship 8), that is, SCMA codeword set S _1,0 The second mapping relationship includes 8 corresponding relationships, and the obtained second mapping relationship of the user J ₁ on the resource block 3 includes 8 corresponding relationships (such as the corresponding relationship 9-corresponding relationship 16), that is, the SCMA codeword set S _3, The second mapping relationship of ₁ includes 8 corresponding relationships. A corresponding relationship is respectively selected from the corresponding relationship 1-corresponding relationship 8 and the corresponding relationship 9-corresponding relationship 16 to determine the peak-to-average power ratio.

Specifically, the peak-to-average power ratios corresponding to correspondence 1 and 9, the peak-to-average power ratios corresponding to correspondence 1 and 10, and similarly, the peak-to-average power ratios corresponding to correspondence 1 and 16 are obtained. Obtain the peak-to-average power ratios corresponding to correspondence 2 and 9, the peak-to-average power ratios corresponding to correspondence 2 and 10, and similarly, the peak-to-average power ratios corresponding to correspondence 2 and 16. Similarly, the peak-to-average power ratios corresponding to correspondences 8 and 9, the peak-to-average power ratios corresponding to correspondences 8 and 10, and similarly, the peak-to-average power ratios corresponding to correspondences 8 and 16 are obtained. Finally, the number of peak-to-average power ratios corresponding to the second mapping relationship of user J ₁ on resource block 1 and resource block 3 is 64. For ease of description, in this embodiment of the present application, a corresponding relationship of a user on resource block 1 and a corresponding relationship of the user on resource block 3 are referred to as a corresponding relationship combination. For example, the corresponding relationship 1 and the corresponding relationship 9 may be referred to as Correspondence combination. Exemplarily, the second mapping relationship of user J ₁ on resource block 1 and the second mapping relationship on resource block 3 correspond to 64 corresponding relationship combinations.

The obtained peak-to-average power is shown in Table 4 below. Taking the modulation order of the SCMA codeword M ₂ =4 and the number of resource blocks occupied by a single user Z = 2 as an example, the obtained 64 corresponding relationship combinations correspond to the peaks. In the average power ratio, the peak-to-average power ratio corresponding to the 32 corresponding relationship combinations is 0dB, and the peak-to-average power ratio corresponding to the 32 corresponding relationship combinations is 2.55dB. Among them, 0dB is less than 2.55dB, so that from the 32 correspondence combinations corresponding to the peak-to-average power ratio 0dB, one correspondence combination can be selected as the third mapping relationship of user J ₁ on resource block 1 and the third mapping relationship on resource block 3. Three mapping relationships. Similarly, assuming that the number of users J=6, a method similar to that of user J ₁ is used to determine the third mapping relationship between user J ₂ and user J ₆ on at least two resource blocks, so that an SCMA with the third mapping relationship can be generated. codebook.

Table 4

In this way, the peak-to-average power ratio after the codeword energy of each user is superimposed on at least two resource blocks is determined, and the corresponding relationship corresponding to the smallest peak-to-average power ratio is selected, thereby ensuring the fairness of power allocation between codewords.

In some embodiments, the peak-to-average power ratio may satisfy the following formula (16):

In the above formula (16), PAPR is the peak-to-average power ratio, M2 represents the modulation order of the SCMA codeword, Z represents the number of resource blocks occupied by a single user,

Represents the modulo value of the SCMA codeword.

The calculation method of the peak-to-average power ratio shown in the above formula (16) is universal, and can be applied to the case of high-order SCMA codewords, different numbers of users, and different numbers of resources.

Exemplarily, the mapping relationship between multi-level symbols and SCMA codewords will affect the signal energy of different codewords, so as to transmit information in resource block 1 and resource block 3 The 4-dimensional complex sequence of each codeword of user J ₁

For example.

The mapping relationship on each resource block (that is, the sequence of SCMA codewords) will affect the codeword energy allocation of user J ₁ on this resource block. The superposition of the respective SCMA codeword energies on the two resource blocks will result in different energy allocation results. . The selection of different mapping relationships for each user will affect the codeword energy allocation for each user. In this embodiment of the present application, the peak-to-average power ratio can be determined, and the multi-ary channel coding symbol and SCMA codeword corresponding to the smallest peak-to-average power ratio can be selected. The mapping relationship between them can ensure the fairness of signal transmission.

The codeword mapping method provided in the embodiment of the present application obtains the first mapping relationship of at least one user on at least two resource blocks, and the first mapping relationship of each user on each resource block is composed of at least two corresponding relationships, Each correspondence is a correspondence between a sparse code division multiple access SCMA codeword and a multi-ary channel coding symbol. Then, determine the second mapping relationship of the at least one user on the at least two resource blocks. Since the second mapping relationship is the one with the smallest corresponding criterion value among the at least two correspondences included in the first mapping relationship, the criterion value is It is used to measure the possibility that the SCMA codeword is decoded incorrectly and the multi-level channel coded symbol is incorrectly decoded. In this way, the mapping relationship is determined based on the bit error performance, which can reduce the bit error rate and improve the bit error performance. On the basis of improving the bit error performance, the peak-to-average power ratio of each user after the codeword energy on at least two resource blocks is superimposed is further determined, and the corresponding relationship is selected according to the peak-to-average power ratio, so that the power between the codewords can be guaranteed. fairness of distribution.

The codeword mapping method provided by the embodiments of the present application has been described in detail above with reference to FIGS. 3-4 . The codeword mapping apparatus provided by the embodiment of the present application is described in detail below with reference to FIG. 5 .

Exemplarily, FIG. 5 is a schematic structural diagram of a codeword mapping apparatus provided by an embodiment of the present application. As shown in FIG. 5 , the codeword mapping apparatus 500 includes: a mapping module 501 and a processing module 502 . For the convenience of description, FIG. 5 only shows the main components of the codeword mapping apparatus.

The mapping module 501 is configured to obtain a first mapping relationship of at least one user on at least two resource blocks. The processing module 502 is configured to determine a second mapping relationship of at least one user on at least two resource blocks. The processing module 502 is further configured to determine the third mapping relationship of the at least one user on the at least two resource blocks according to the peak-to-average power ratio corresponding to the second mapping relationship of the at least one user on the at least two resource blocks.

In a possible design manner, at least two resource blocks may include a first resource block and a second resource block, and at least one user may include the first user. The processing module 502 is further configured to obtain the peak-to-average power ratio according to the second mapping relationship of the first user on the first resource block and the second mapping relationship of the first user on the second resource block. The peak-to-average power ratio may include at least two peak-to-average power ratios, and the minimum value of the at least two peak-to-average power ratios is the first peak-to-average power ratio. The processing module 502 is further configured to respectively determine the second mapping relationship on the first resource block and the second mapping relationship on the second resource block corresponding to the first peak-to-average power ratio as the first user in the first resource The third mapping relationship on the block and the third mapping relationship of the first user on the second resource block.

In a possible design manner, the mapping module 501 is further configured to obtain the basic SCMA codeword set according to the first Euclidean criterion. The first Euclidean criterion may include maximizing the minimum Euclidean distance between SCMA codewords of one user on one resource block, and the basic SCMA codeword set may include SCMA codewords of one user on one resource block. The mapping module 501 is further configured to obtain a one-dimensional SCMA codeword set according to the basic SCMA codeword set and the second Euclidean criterion. The one-dimensional SCMA codeword set may include SCMA codewords of at least two users on one resource block, and the second Euclidean criterion may include the minimum Euclidean distance between the SCMA codewords of at least two users on one resource block and maximize.

Represents SCMA codeword

a multiple of the SCMA codeword r ₁ ,

Represents SCMA codeword

a multiple of the SCMA codeword r ₁ ,

represents the SCMA codeword obtained by the first Euclidean criterion

A multiple of the SCMA codeword r ₁ , i ₁ can range from 1 to

Integer between , i ₂ can range from 1 to

An integer between, M ₂ represents the modulation order of the SCMA codeword.

In one possible design, the metric can satisfy the following relationship:

in,

Indicates that the sequence number of user u on resource block k is

The codeword of , the operator symbol |||| means modulo.

is the sequence number of the second SCMA codeword,

is the Hamming distance, c ₁ is the first multi-ary channel coding symbol,

Code symbols for the second multi-ary channel.

It should be noted that the mapping module 501 and the processing module 502 may be set separately, or may be integrated into one module, that is, the processing module (not shown in FIG. 5 ). The present application does not specifically limit the specific implementation manners of the mapping module 501 and the processing module 502 .

Optionally, the codeword mapping apparatus 500 may further include a transceiver module (not shown in FIG. 5 ). The transceiver module is used to receive data and/or signaling sent by other devices, and may also be used to send data and/or signaling to other devices. Further, the transceiver module may include a receiving module and a transmitting module (not shown in FIG. 5 ). The receiving module is used to receive data and/or signaling sent by other devices, and the sending module is used to send data and/or signaling to other devices. This application does not specifically limit the specific implementation manner of the transceiver module.

Optionally, the codeword mapping apparatus 500 may further include a storage module (not shown in FIG. 5 ), where the storage module stores programs or instructions. When the processing module executes the program or the instruction, the codeword mapping apparatus 500 can execute the codeword mapping method shown in FIG. 3 .

It should be noted that the codeword mapping apparatus 500 may be a terminal device, or may be a chip (system) or other components or components that can be provided in the terminal device, which is not limited in this application.

In addition, for the technical effect of the codeword mapping apparatus 500, reference may be made to the technical effect of the codeword mapping method shown in FIG. 3 , which will not be repeated here.

An embodiment of the present application provides a chip system, where the chip system includes a processor and an input/output port, where the processor is used to implement the processing functions involved in the foregoing method embodiments, and the input/output port is used to implement the foregoing method implementation Send and receive functions involved in the example.

In a possible design, the chip system further includes a memory for storing program instructions and data for implementing the functions involved in the above method embodiments.

An embodiment of the present application provides a computer-readable storage medium, including: the computer-readable storage medium includes a computer program or instruction, and when the computer program or instruction runs on a computer, the computer is made to execute the method described in the foregoing method embodiment. codeword mapping method.

An embodiment of the present application provides a computer program product containing instructions, the computer program product includes: a computer program or an instruction, when the computer program or instruction is run on a computer, the computer is made to execute the method described in the foregoing method embodiment. Codeword mapping method.

It should be understood that the processor in the embodiments of the present application may be a central processing unit (central processing unit, CPU), and the processor may also be other general-purpose processors, digital signal processors (digital signal processors, DSP), dedicated integrated Circuit (application specific integrated circuit, ASIC), off-the-shelf programmable gate array (field programmable gate array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

It should also be understood that the memory in the embodiments of the present application may be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory may be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically programmable Erase programmable read-only memory (electrically EPROM, EEPROM) or flash memory. Volatile memory may be random access memory (RAM), which acts as an external cache. By way of example and not limitation, many forms of random access memory (RAM) are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (DRAM) Access memory (synchronous DRAM, SDRAM), double data rate synchronous dynamic random access memory (double data rate SDRAM, DDR SDRAM), enhanced synchronous dynamic random access memory (enhanced SDRAM, ESDRAM), synchronous connection dynamic random access memory Fetch memory (synchlink DRAM, SLDRAM) and direct memory bus random access memory (direct rambus RAM, DR RAM).

The above embodiments may be implemented in whole or in part by software, hardware (eg, circuits), firmware, or any other combination. When implemented in software, the above-described embodiments may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, all or part of the processes or functions described in the embodiments of the present application are generated. The computer may be a general purpose computer, special purpose computer, computer network, or other programmable device. The computer instructions may be stored in or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be downloaded from a website site, computer, server, or data center Transmission to another website site, computer, server or data center by wire (eg, infrared, wireless, microwave, etc.). The computer-readable storage medium may be any available medium that a computer can access, or a data storage device such as a server, a data center, or the like containing one or more sets of available media. The usable media may be magnetic media (eg, floppy disks, hard disks, magnetic tapes), optical media (eg, DVDs), or semiconductor media. The semiconductor medium may be a solid state drive.

It should be understood that the term "and/or" in this document is only an association relationship to describe associated objects, indicating that there can be three kinds of relationships, for example, A and/or B, which can mean that A exists alone, and A and B exist at the same time , there are three cases of B alone, where A and B can be singular or plural. In addition, the character "/" in this document generally indicates that the related objects before and after are an "or" relationship, but may also indicate an "and/or" relationship, which can be understood with reference to the context.

In this application, "at least one" means one or more, and "plurality" means two or more. "At least one item(s) below" or similar expressions thereof refer to any combination of these items, including any combination of single item(s) or plural items(s). For example, at least one item (a) of a, b, or c can represent: a, b, c, a-b, a-c, b-c, or a-b-c, where a, b, c may be single or multiple .

It should be understood that, in various embodiments of the present application, the size of the sequence numbers of the above-mentioned processes does not mean the sequence of execution, and the execution sequence of each process should be determined by its functions and internal logic, and should not be dealt with in the embodiments of the present application. implementation constitutes any limitation.

Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may implement the described functionality using different methods for each particular application, but such implementations should not be considered beyond the scope of this application.

Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the above-described systems, devices and units may refer to the corresponding processes in the foregoing method embodiments, which will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed system, apparatus and method may be implemented in other manners. For example, the apparatus embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored, or not implemented. On the other hand, the shown or discussed mutual coupling or direct coupling or communication connection may be through some interfaces, indirect coupling or communication connection of devices or units, and may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution in this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit.

The functions, if implemented in the form of software functional units and sold or used as independent products, may be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be embodied in the form of a software product in essence, or the part that contributes to the prior art or the part of the technical solution. The computer software product is stored in a storage medium, including Several instructions are used to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), magnetic disk or optical disk and other media that can store program codes .

The above are only specific embodiments of the present application, but the protection scope of the present application is not limited to this. should be covered within the scope of protection of this application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

A codeword mapping method, comprising:

Obtain the first mapping relationship of at least one user on at least two resource blocks; wherein, the first mapping relationship of each user on each resource block is composed of at least two corresponding relationships, and each corresponding relationship is sparse code division multiple The correspondence between the address SCMA codeword and the multi-ary channel coding symbol;

determining the second mapping relationship of the at least one user on the at least two resource blocks; wherein, the second mapping relationship of each user on each resource block is composed of at least one corresponding relationship, and the at least one corresponding relationship is the correspondence relationship with the smallest corresponding criterion value among the at least two correspondences, and the criterion value is used to measure the possibility that the SCMA codeword is erroneously decoded and the multi-ary channel coded symbol is erroneously decoded;

Determine the third mapping relationship of the at least one user on the at least two resource blocks according to the peak-to-average power ratio corresponding to the second mapping relationship of the at least one user on the at least two resource blocks; wherein, The third mapping relationship of each user on each resource block is a corresponding relationship, and the one corresponding relationship is one of the at least one corresponding relationship, and the peak-to-average power ratio is the energy of the SCMA codeword where the The peak-to-average power ratio superimposed on the at least two resource blocks.
The codeword mapping method according to claim 1, wherein the multi-ary channel coding symbol comprises a first multi-ary channel coding symbol and a second multi-ary channel coding symbol, and the SCMA code word comprises a first multi-ary channel coding symbol and a second multi-ary channel coding symbol. An SCMA codeword and a second SCMA codeword; the criterion value is determined according to the Hamming distance and the Euclidean distance, and the Hamming distance is the first multi-ary channel coding symbol and the second multi-ary channel coding symbol. The number of bits with different values in the corresponding bits between the channel coding symbols, the Euclidean distance is the Euclidean spatial geometric distance between the first SCMA codeword and the second SCMA codeword, and the first The multi-level channel coding symbol corresponds to the first SCMA codeword, the second multi-level channel coding symbol corresponds to the second SCMA codeword, and the first SCMA codeword is the codeword currently to be decoded , the second SCMA codeword is different from the first SCMA codeword.
The codeword mapping method according to claim 2, wherein the criterion value comprises traversing and stacking a product of at least one of the Hamming distances and at least one corresponding metric criterion, wherein the metric criterion is based on the Euclidean distance definite.
The codeword mapping method according to any one of claims 1-3, wherein the at least two resource blocks include a first resource block and a second resource block, and the at least one user includes a first user;

determining the third mapping relationship of the at least one user on the at least two resource blocks according to the peak-to-average power ratio corresponding to the second mapping relationship of the at least one user on the at least two resource blocks, include:

A peak-to-average power ratio is obtained according to the second mapping relationship of the first user on the first resource block and the second mapping relationship of the first user on the second resource block; wherein the peak-to-average power ratio is The average power ratio includes at least two peak-to-average power ratios, and the minimum value of the at least two peak-to-average power ratios is the first peak-to-average power ratio;

Determining the second mapping relationship on the first resource block and the second mapping relationship on the second resource block corresponding to the first peak-to-average power ratio as the first user in the The third mapping relationship on the first resource block and the third mapping relationship of the first user on the second resource block.
The codeword mapping method according to any one of claims 1-4, wherein the method further comprises:

A basic SCMA codeword set is obtained according to a first Euclidean criterion; wherein the first Euclidean criterion includes maximizing the minimum Euclidean distance between SCMA codewords of a user on one resource block, and the basic SCMA codeword set includes in the SCMA codeword of the one user on the one resource block;

According to the basic SCMA codeword set and the second Euclidean criterion, a one-dimensional SCMA codeword set is obtained; wherein, the one-dimensional SCMA codeword set includes the SCMA codeword of at least one user on the one resource block, and the The second Euclidean criterion includes a minimum Euclidean distance sum maximization between SCMA codewords of at least two users on the one resource block.
The codeword mapping method according to claim 5, wherein the first Euclidean criterion satisfies the following relationship:

Wherein, r 1 represents the value of the SCMA codeword with the smallest modulus value in the basic SCMA codeword set, and r 1 * represents the SCMA code with the smallest modulus value in the basic SCMA codeword set obtained by the first Euclidean criterion word value,
Represents SCMA codeword
a multiple of the SCMA codeword r 1 ,
Represents SCMA codeword
and a multiple of the SCMA codeword r 1 ,
represents the multiple between the SCMA codeword r2 and the SCMA codeword r1 obtained by the first Euclidean criterion,
represents the SCMA codeword obtained by the first Euclidean criterion
A multiple of the SCMA codeword r 1 , the value range of i 1 is 1 to
Integer between , i 2 can range from 1 to
An integer between, M 2 represents the modulation order of the SCMA codeword.
The codeword mapping method according to claim 5 or 6, wherein the second Euclidean criterion satisfies the following relationship:

Wherein, θ 1 * represents the angle between the SCMA codeword set of the user whose sequence number is 1 obtained through the second Euclidean criterion and the basic SCMA codeword set, and θ 1 represents the SCMA codeword set of the user whose sequence number is 1 the initial angle between the codeword set and the base SCMA codeword set, j represents the imaginary part of the complex number,
represents the codeword with sequence number m 1 in the basic SCMA codeword set, m 1 =1,2,...,M 2 , d f represents the number of users superimposed on one resource block, and the operator symbol || | | means taking the modulo.
The codeword mapping method according to any one of claims 1-7, wherein the metric satisfies the following relationship:

in,
is the metric, m 1 represents the sequence number of the first SCMA codeword,
denotes the sequence number of the second SCMA codeword, k denotes the sequence number of the resource block, u denotes the sequence number of the user, and x u,k (m 1 ) denotes that the sequence number of the user u on the resource block k is m 1 codeword, the
Indicates that the sequence number of user u on resource block k is
The codeword of , the operator symbol || || means modulo.
The codeword mapping method according to claim 8, wherein the criterion value satisfies the following relationship:

Wherein, E mapping is the criterion value, M 2 represents the modulation order of the SCMA codeword, m 1 is the sequence number of the first SCMA codeword,
is the sequence number of the second SCMA codeword,
is the Hamming distance, c 1 is the first multi-ary channel coding symbol,
Symbols are encoded for the second multi-ary channel.
The codeword mapping method according to any one of claims 1-9, wherein the peak-to-average power ratio satisfies the following relationship:

Wherein, PAPR is the peak-to-average power ratio, M 2 represents the modulation order of the SCMA codeword, Z represents the number of resource blocks occupied by a single user, and A zm represents the modulus value of the SCMA codeword.
A codeword mapping device, comprising: a mapping module and a processing module; wherein,

The mapping module is configured to obtain a first mapping relationship of at least one user on at least two resource blocks; wherein, the first mapping relationship of each user on each resource block is composed of at least two corresponding relationships, each The corresponding relationship is the corresponding relationship between the sparse code division multiple access SCMA codeword and the multi-ary channel coding symbol;

The processing module is configured to determine the second mapping relationship of the at least one user on the at least two resource blocks; wherein the second mapping relationship of each user on each resource block is composed of at least one corresponding relationship , the at least one correspondence is the correspondence with the smallest corresponding criterion value among the at least two correspondences, and the criterion value is used to measure that the SCMA codeword is erroneously decoded and the multi-level channel coded symbol is erroneously decoded. the possibility of incorrect decoding;

The processing module is further configured to determine that the at least one user is on the at least two resource blocks according to the peak-to-average power ratio corresponding to the second mapping relationship of the at least one user on the at least two resource blocks The third mapping relationship; wherein, the third mapping relationship of each user on each resource block is a corresponding relationship, the one corresponding relationship is one of the at least one corresponding relationship, and the peak-to-average power ratio is all The peak-to-average power ratio after the energy of the SCMA codeword is superimposed on the at least two resource blocks.
The codeword mapping apparatus according to claim 11, wherein the multi-ary channel coding symbol comprises a first multi-ary channel coding symbol and a second multi-ary channel coding symbol, and the SCMA code word comprises a first multi-ary channel coding symbol and a second multi-ary channel coding symbol. An SCMA codeword and a second SCMA codeword; the criterion value is determined according to the Hamming distance and the Euclidean distance, and the Hamming distance is the first multi-ary channel coding symbol and the second multi-ary channel coding symbol. The number of bits with different values in the corresponding bits between channel coding symbols, the Euclidean distance is the Euclidean spatial geometric distance between the first SCMA codeword and the second SCMA codeword, and the first The multi-level channel coding symbol corresponds to the first SCMA codeword, the second multi-level channel coding symbol corresponds to the second SCMA codeword, and the first SCMA codeword is the codeword currently to be decoded , the second SCMA codeword is different from the first SCMA codeword.
The codeword mapping apparatus according to claim 12, wherein the criterion value comprises traversing and stacking a product of at least one of the Hamming distances and at least one corresponding metric criterion, wherein the metric criterion is based on the Euclidean distance definite.
The codeword mapping apparatus according to any one of claims 11-13, wherein the at least two resource blocks include a first resource block and a second resource block, and the at least one user includes a first user;

The processing module is further configured to obtain the peak average value according to the second mapping relationship of the first user on the first resource block and the second mapping relationship of the first user on the second resource block. Power ratio; wherein, the peak-to-average power ratio includes at least two peak-to-average power ratios, and the minimum value of the at least two peak-to-average power ratios is the first peak-to-average power ratio;

The processing module is further configured to respectively determine the second mapping relationship on the first resource block and the second mapping relationship on the second resource block corresponding to the first peak-to-average power ratio as The third mapping relationship of the first user on the first resource block and the third mapping relationship of the first user on the second resource block.
The codeword mapping apparatus according to any one of claims 11-14, wherein,

The mapping module is further configured to obtain a basic SCMA codeword set according to a first Euclidean criterion; wherein, the first Euclidean criterion includes maximizing the minimum Euclidean distance between SCMA codewords of a user on a resource block, so The basic SCMA codeword set includes the SCMA codeword of the one user on the one resource block;

The mapping module is further configured to obtain a one-dimensional SCMA codeword set according to the basic SCMA codeword set and the second Euclidean criterion; wherein, the one-dimensional SCMA codeword set includes at least one on the one resource block The user's SCMA codeword, the second Euclidean criterion includes a minimum Euclidean distance sum maximization between at least two user's SCMA codewords on the one resource block.
The codeword mapping apparatus according to claim 15, wherein the first Euclidean criterion satisfies the following relationship:

Wherein, r 1 represents the value of the SCMA codeword with the smallest modulus value in the basic SCMA codeword set, and r 1 * represents the SCMA code with the smallest modulus value in the basic SCMA codeword set obtained by the first Euclidean criterion word value,
Represents SCMA codeword
a multiple of the SCMA codeword r 1 ,
Represents SCMA codeword
and a multiple of the SCMA codeword r 1 ,
represents the multiple between the SCMA codeword r2 and the SCMA codeword r1 obtained by the first Euclidean criterion,
represents the SCMA codeword obtained by the first Euclidean criterion
A multiple of the SCMA codeword r 1 , the value range of i 1 is 1 to
Integer between , i 2 can range from 1 to
An integer between, M 2 represents the modulation order of the SCMA codeword.
The codeword mapping apparatus according to claim 15 or 16, wherein the second Euclidean criterion satisfies the following relationship:

Wherein, θ 1 * represents the angle between the SCMA codeword set of the user whose sequence number is 1 obtained through the second Euclidean criterion and the basic SCMA codeword set, and θ 1 represents the SCMA codeword set of the user whose sequence number is 1 the initial angle between the codeword set and the base SCMA codeword set, j represents the imaginary part of the complex number,
represents the codeword with sequence number m 1 in the basic SCMA codeword set, m 1 =1,2,...,M 2 , d f represents the number of users superimposed on one resource block, and the operator symbol || | | means taking the modulo.
The codeword mapping apparatus according to any one of claims 11-17, wherein the metric criterion satisfies the following relationship:

in,
is the metric, m 1 represents the sequence number of the first SCMA codeword,
denotes the sequence number of the second SCMA codeword, k denotes the sequence number of the resource block, u denotes the sequence number of the user, and x u,k (m 1 ) denotes that the sequence number of the user u on the resource block k is m 1 codeword, the
Indicates that the sequence number of user u on resource block k is
The codeword of , the operator symbol || || means modulo.
The codeword mapping apparatus according to claim 18, wherein the criterion value satisfies the following relationship:

Wherein, E mapping is the criterion value, M 2 represents the modulation order of the SCMA codeword, m 1 is the sequence number of the first SCMA codeword,
is the sequence number of the second SCMA codeword,
is the Hamming distance, c 1 is the first multi-ary channel coding symbol,
Symbols are encoded for the second multi-ary channel.
The codeword mapping apparatus according to any one of claims 11-19, wherein the peak-to-average power ratio satisfies the following relationship:

Wherein, PAPR is the peak-to-average power ratio, M 2 represents the modulation order of the SCMA codeword, Z represents the number of resource blocks occupied by a single user, and A zm represents the modulus value of the SCMA codeword.
A codeword mapping apparatus, characterized in that the codeword mapping apparatus comprises: a processor, and the processor is coupled to a memory;

the memory for storing computer programs;

The processor is configured to execute the computer program stored in the memory, so that the codeword mapping apparatus executes the codeword mapping method according to any one of claims 1-10.
A computer-readable storage medium, characterized in that the computer-readable storage medium comprises a computer program or instruction, which, when the computer program or instruction is executed on a computer, causes the computer to perform as in claims 1-10 Any one of the codeword mapping methods.
A computer program product, characterized in that the computer program product comprises: a computer program or instruction, when the computer program or instruction is run on a computer, the computer is made to execute any one of claims 1-10 The codeword mapping method.