User identification-free shared codebook multiple access transmission method approaching theoretical capacity in finite field

Abstract

The invention discloses a user identification-free shared codebook multiple access transmission method (URA, Unsourced Random Access) approaching the theoretical capacity in a finite field, information source data of each user side is coded according to the coding method provided by the invention, signals are transmitted according to the disclosed sending method, multi-user signals are dispersed in a plurality of subframes, and the transmission efficiency is improved. The disclosed coding and sending method can construct a subframe signal with strong noise immunity, and the disclosed decoding method completes detection and estimation of active sequence codeword channel state information according to signal sending energy and noise statistical information estimation and a pre-stored spread spectrum sequence codebook, and carries out state information soft demodulation and decoding on a subframe time slot at the same time. In addition, recovery information through parity check is repeatedly used for serial interference cancellation, and the iterative operation can improve system performance. In a finite field, the scheme improves the user capacity of multi-antenna multi-access, and approaches to the reachable theoretical capacity of the multi-access of the non-user identification shared codebook under multiple antennas.

Description

Technical Field

[0001] The invention belongs to the field of wireless / digital communication, and in particular relates to a shared codebook multiple access transmission method without user identification that approximates theoretical capacity under a finite field. Background Art

[0002] Vertical industry applications represented by the Internet of Things have become one of the main factors driving the development of post-5G and 6G mobile communication systems. Compared with 5G, 6G is expected to be improved in performance indicators such as data transmission rate, number of device access, and communication latency to better support diverse application needs. Among them, ultra-large-scale connections (also known as giant connections, giant address access, etc.) cover multiple industry applications in the future, such as low-power and wide-coverage Internet of Things, smart agriculture, and integrated transportation.

[0003] Massive Machine Type Communication (mMTC) is committed to supporting the next generation of wireless communication systems with dense number of machine-type devices interacting with each other, the trend and demand of sporadic traffic communication of many mainstream services, short packet transmission, and low power consumption. In this case, Unsourced Random / Multiple Access (URA) has become a potential supporting technology route. Massive antenna technology (Massive MIMO, Massive Multiple Input Multiple Output) has a significant effect on improving the capacity and service quality of communication systems, and is therefore widely used. The combination of massive antenna systems and Unsourced Random / Multiple Access is imperative.

[0004] Recently, the academic community has proved that the performance of user-identifier-free shared codebook multiple access in large-scale antenna systems can be achieved. At present, there is no solution that can approach the theoretical achievable limit. Based on this situation, the present invention designs a user-identifier-free shared codebook multiple access transmission method that approaches the theoretical capacity in a finite field. The system design is simple and easy, and has the characteristics of low power consumption. Compared with other transmission schemes, it can approach the theoretical capacity. Summary of the invention

[0005] The present invention aims at improving the system capacity of a system equipped with a large-scale antenna under the mMTC service in a limited domain. The transmission method disclosed in the present invention divides a signal frame of a fixed total length into several subframes, each subframe is divided into two subframe blocks, and the subframe blocks respectively carry spread spectrum sequence signals from multiple users and constellation point modulation signals after multiple transmission modes are arranged. The decoding method first estimates the number of active users contained in each subframe signal according to the signal transmission energy and noise statistical information, and then detects and estimates the channel state information according to the pre-stored spread spectrum sequence codebook. After obtaining the active sequence codeword information and the corresponding channel state information, the subframe time slot is soft-demodulated for state information. The obtained soft demodulation state information is used to simultaneously complete the transmission mode active detection and the corresponding constellation point soft demodulation. The constellation point soft demodulation information is used to calculate the bit likelihood soft information, and the forward error correction decoding of the channel coding is performed based on the bit likelihood soft information. In addition, the recovered information through the parity check is repeatedly used for serial interference elimination, and this iterative operation can improve the system performance. Under a finite field, the above scheme improves the user capacity of multi-antenna multiple access, and approaches the theoretical capacity of multi-access without user identification shared codebook under multiple antennas. In order to achieve the above purpose, the technical scheme of the present invention is as follows: a method for multiple access transmission without user identification shared codebook (URA, Unsourced Random Access) that approaches the theoretical capacity under a finite field, a source bit data encoding method, a sending method, and a decoding method for multiple access transmission without user identification shared codebook. The disclosed decoding method corresponds to the disclosed encoding method and the sending method. At the same time, different from the multiple access encoding and decoding focused on in the related field under a single-antenna Gaussian address channel, the decoding method disclosed in the present invention is suitable for the uplink communication access process under a large-scale antenna configuration, and the single-antenna system essentially does not have the conditions required for the decoding method disclosed in the present invention. Specifically, the decoding method disclosed in the present invention needs to complete the estimation and recovery of multi-user constellation point symbols and transmission transmission modes based on the estimated channel state information, while the single-antenna receiving end cannot provide sufficient signal observations, and can only provide a received signal with a rank of 1, which is not enough to provide information equivalent to the amount to be estimated.

[0006] As an improvement of the present invention, the encoding method includes:

[0007] Source bit data and its division and encoding method;

[0008] Pre-stored spreading sequence codebook and transmission mode codebook;

[0009] The source bit data is divided and encoded into a subframe selection bit sequence, a preamble selection bit sequence, a transmission mode selection bit sequence, and a sending bit sequence, and corresponding encoding is completed respectively;

[0010] Through the subframe selection bit sequence, the user selects the subframe position for sending information;

[0011] Through the leading selection bit sequence, the user selects the corresponding spreading sequence codeword from the pre-stored spreading sequence codebook;

[0012] Through the transmission mode selection bit sequence, the user selects multiple transmission modes from a pre-stored transmission mode codebook;

[0013] The transmission bit sequence is channel coded and constellation point modulated, and is arranged by the multiple transmission modes selected by the transmission mode selection bit sequence. After the arrangement is completed, the channel transmission is completed according to the preset transmission method; the coding method, the source bit data is divided into multiple sub-blocks, which are respectively a subframe selection bit sequence, a preamble selection bit sequence, a transmission mode selection bit sequence, and a transmission bit sequence;

[0014] The subframe selection bit sequence determines the subframe position occupied by the user, and the transmission mode selection bit sequence determines the arrangement of subsequent modulation constellation points;

[0015] The subframe selection bit sequence and the transmission mode selection bit sequence do not participate in channel coding and constellation point modulation, thereby reducing the number of modulation constellation points that need to be sent subsequently;

[0016] The transmission mode selection bit sequence selects a multi-terminal transmission mode for the tail of the subframe. Since the size of the transmission mode codebook grows exponentially, the transmission mode selection bit sequence selects multiple transmission modes in segments for subsequent arrangement. Therefore, only a relatively small-sized transmission mode codebook needs to be pre-stored, which is beneficial to reduce storage requirements.

[0017] As an improvement of the present invention, the sending method includes:

[0018] A channel with a fixed channel usage under a finite field is divided into a plurality of subframe positions;

[0019] The selected spread spectrum sequence codeword is located at the head of the subframe, and together with the constellation point symbol arranged in multiple transmission modes at the tail of the subframe, constitutes a complete subframe;

[0020] Complete signal transmission based on the selected subframe position;

[0021] Based on the subframe selection bit sequence, only signals of some users are superimposed at the subframe position in each subframe;

[0022] The receiving end receives all subframe signals under the finite field, and based on the set decoding method, completes the recovery of the source data for each subframe one by one;

[0023] In the transmission method, only the corresponding signals of the encoded leading selection bit sequence and the transmission bit sequence need to be transmitted;

[0024] The collision probability of the preamble signal, i.e., the spread spectrum sequence codeword / pilot signal, is reduced. Since the subframe position is randomly selected by the subframe selection bit sequence, and the preamble selection bit sequence selects the spread spectrum sequence codeword randomly, the multi-user collision probability of the pilot codeword used to estimate the channel state information can be controlled to be extremely low (if the pilot signals of the estimated channel between multiple users collide, only the overlapping channel coefficients can be estimated, and the overlapping channel coefficients cannot support subsequent symbol detection, resulting in communication failure);

[0025] The subframe selection bit sequence and the transmission mode selection bit sequence do not participate in channel coding and constellation point modulation, and do not generate redundant signal units that need to be sent, thereby reducing the redundancy of transmission, increasing the unit energy of the modulation constellation point, and improving the anti-noise performance of the system;

[0026] The transmission mode sequence selected by the transmission mode selection bit sequence is an independent operation and does not depend on other data source bits. At the same time, the sparse subframe tail structure is conducive to reducing crosstalk between multiple users.

[0027] As an improvement of the present invention, the decoding method for recovering the source data includes (the signal recovery method for each subframe is the same):

[0028] Estimating the number of active users in a subframe based on the transmitted signal energy and noise statistics;

[0029] Based on the multi-user spread spectrum sequence codeword signal superimposed on the subframe header, the spread spectrum sequence codeword activity detection and the corresponding channel state information estimation are completed;

[0030] Based on the channel state information estimation, soft demodulation of time slot subframe state information is completed;

[0031] Based on the soft demodulation time slot subframe state information, complete the transmission mode active detection and corresponding constellation point soft demodulation;

[0032] Calculate the bit likelihood soft information based on the transmission mode active detection result and the constellation point soft demodulation information;

[0033] Based on the bit likelihood soft information, performing forward error correction decoding of the channel coding;

[0034] Based on the result of the forward error correction decoding, performing a parity check on the decoded data sequence;

[0035] Based on the parity check result, serial interference elimination is performed, and the signal that has undergone the encoding method and transmission method again is removed from the received signal, and the above decoding method is repeated until there is no data sequence that passes the parity check.

[0036] The decoding method for recovering source data,

[0037] The recovery of the subframe selection bit sequence does not require additional computational complexity and energy consumption, and only requires active estimation of the spread spectrum sequence codeword completed by the subframe header signal at the corresponding subframe position.

[0038] Recover the subframe selection bit sequence of the user at the corresponding subframe position;

[0039] The transmission mode selection bit sequence recovery does not require additional signals, but is based on the time slot status

[0040] Soft information demodulator to estimate;

[0041] The transmission mode selection bit sequence is restored simultaneously with the transmission bit sequence.

[0042] The recovery of the bit sequence is accompanied by the estimation of the correct transmission mode;

[0043] The serial interference elimination in the recovery method takes into account the correction of channel information, further enhancing the system source bit data recovery capability

[0044] Specifically:

[0045] For the encoding method:

[0046] The total channel usage in the finite domain is represented by L, the amount of source bit data is B, and the number of active users per antenna is K a , the number of antennas at the receiving end is M.

[0047] The source bit data is divided into B ck ,B pn ,B p ,B c , respectively selecting a bit sequence for the subframe, selecting a bit sequence for the preamble, selecting a bit sequence for the transmission mode, and sending a bit sequence. ck The bit data value selects the subframe position, so the total channel usage of the finite field needs to be divided into subframes, the subframe header is L p and tail length L c , if the subframe lengths are the same, then the constraint is satisfied

[0048]

[0049] Due to the randomness of subframe position selection, the number of active users at a single subframe position is given by Indicates; through the B pn Bit Data Selection J p transmission mode codewords, determine the subsequent arrangement mode; through the B pThe bit data value selects the spread spectrum sequence codeword, so the spread spectrum sequence codebook needs to have Spread spectrum sequence codewords, define the spread spectrum sequence codebook as

[0050]

[0051] The selected spreading sequence codeword is determined by Indicates; said B c Bits of data need to go through channel coding, constellation point symbol modulation and transmission mode arrangement. The channel coding rate is expressed as R c The constellation point symbol modulation order is represented by Q. Therefore, after channel coding and symbol modulation, the number of constellation point symbols that need to be arranged is

[0052]

[0053] According to the above encoding method, the transmission mode codebook can be defined as

[0054]

[0055] The total number of transmission mode codebooks is transmission mode codewords, each of which has only S non-zero elements. The position of the non-zero element indicates the position of the constellation point symbol, and the position of the zero element indicates that there is no transmission signal. p The tail of the subframe after the transmission mode is arranged is Here is an example of how to arrange the constellation points according to the transmission mode codeword. If there is a transmission mode codeword [0,1,0,1,0,0] and a constellation point symbol [s1,s2], the following combinations can be arranged: [0,s1,0,s2,0,0] or

[0056] [0,s1,0,s2,0,0], that is, the order of symbols after arrangement can be set flexibly.

[0057] For the sending method:

[0058] The signal of a single subframe superposition can be expressed as The superposition signal of multi-user spread spectrum sequence codeword signal (including additive Gaussian white noise) is: The frame header receives the signal

[0059] The body expression is

[0060]

[0061] in represents a user's spreading sequence codeword vector, is the channel coefficient vector of a certain user, and the additive Gaussian white noise in the frame header is Follow the mean 0 variance σ2 The cyclically symmetric complex Gaussian distribution of multiple users through multiple transmission modes is superimposed on the constellation point symbol signal (including additive Gaussian white noise) The specific expression of the received signal at the end of the frame is:

[0062]

[0063] in is the constellation point signal arranged in multiple transmission modes, and the additive Gaussian white noise at the end of the frame is Follow the mean 0 variance σ 2 The cyclically symmetric complex Gaussian distribution of . At the same time, the transmission energy constraint of the signal is determined by the bit signal-to-noise ratio (energy-per-bit), which is defined as

[0064]

[0065] The total signal transmission energy constraint of a single user is P, E s is the unit channel usage energy, and the power allocation coefficient α is defined as the proportion allocated to a single user in the subframe header, that is, the single-user subframe header signal satisfies the energy constraint The energy constraint of the subframe tail signal is

[0066] For the decoding method:

[0067] The processing method for each subframe is the same, and the following is a detailed description of the received signal of a single subframe.

[0068] Due to the randomness of subframe position selection, the receiver needs to estimate the number of active users in each subframe.

[0069] The number of active users is calculated based on the energy constraint of the transmitted signal and the noise statistics. Make rounding estimates

[0070]

[0071] in is the average received signal energy of a single antenna. Number of active users That is equivalent to the number of active spreading sequence codeword sequences.

[0072] After estimating the signal reception energy, the receiver needs to complete the estimation of the channel state information:

[0073] The subframe header receiving signal can be equivalent to

[0074] Y p =AH+Z p

[0075] The channel matrix H has only The rows are non-zero vectors, and the rest are zero vectors; the non-zero vectors of the channel matrix represent the channel coefficients of the active spread spectrum sequence codewords; solving the channel coefficients can be equivalent to solving the compressed sensing problem, and many common methods can solve this type of problem. Here, according to the idea of ​​multi-antenna orthogonal matching pursuit (SOMP, Simultaneous Orthogonal Matching Pursuit), the active detection of spread spectrum sequence codewords and the corresponding channel state information estimation are performed according to the pre-stored common spread spectrum sequence codebook; in each loop, SOMP selects the measurement matrix column with the largest correlation with the current residual and adds its index to the output list, that is, the active detection of spread spectrum sequence codewords is completed; the detected active spread spectrum sequence codewords are used for channel coefficient estimation and residual update; the number of loops can be set to The residual R can be initialized to the subframe header received signal, and the spread spectrum sequence codeword correlation / active detection is calculated as

[0076]

[0077] The sequence number of the active codeword is stored in In; the orthogonal projection is constructed by determining the active codeword sequence, let Then the residual is updated to

[0078]

[0079] in is the Moore-Penrose generalized inverse, and the sequence numbers of all active codewords are obtained through repeated iterations; the channel estimation corresponding to the active spreading sequence codeword can be completed in different ways, such as the channel coefficient estimation based on the minimum mean square error (MMSE) error criterion is

[0080]

[0081] After obtaining the estimated channel coefficients, the receiving end performs soft demodulation on the state information of the subframe tail time slot: First, define the subframe time slot state for

[0082]

[0083] Where s0=0 is the idle state, {s1,…,s Q} is the active state, i.e. the constellation point symbol after arrangement,

[0084] is the energy constraint for a single constellation point symbol.

[0085] No.1 c The soft demodulation signal model of a time slot is:

[0086]

[0087] in Y c A column represents a single time slot received signal, and z is the corresponding additive Gaussian white noise. The soft demodulation method of the time slot status information is the same, and different time slots can be performed independently. The subsequent detailed description is for a single

[0088] Time slot signal processing. The time slot signal model after channel equalization can be obtained:

[0089]

[0090] in z can be equivalent to a matrix with zero mean and covariance Gaussian noise. State soft information demodulation aims to calculate the time slot state corresponding to each element in x The posterior probability of the state element in , Used to represent the element x to be estimated i ∈x and the posterior probability of each time slot state. To solve the element x i The state posterior probability is introduced, and the guidance vector The guidance vector has only one non-zero element 1 at the i-th position. After introducing the guidance vector, we can get

[0091]

[0092] The signals other than the target element (Target) are considered as pseudo noise Pseudo noise has a statistical mean matrix (Mean Matrix) E i , Covariance Matrix Ω i , Pseudo Covariance MatrixΞ i , considering interference as noise, the above statistics can be obtained by the following calculation

[0093]

[0094] Process variables ω j ,ξ j It can be obtained by the following calculation

[0095]

[0096] At the same time, the prior probability of each time slot state can be obtained through the encoding method and the sending method.

[0097]

[0098] After obtaining the above statistics, the fixed estimation element is a certain time slot state And calculate the signal residual in this state

[0099]

[0100] Based on this residual calculation, the likelihood value of the corresponding state can be calculated

[0101]

[0102] in Represent the real and imaginary parts of the complex number, respectively, and the process variable Λ i The noise statistics can be obtained

[0103]

[0104] After the above solution, the element x i The posterior probability of the time slot state can be calculated by the likelihood value

[0105]

[0106] The above time slot state soft information demodulation solution process is iterated repeatedly, divided into an inner loop and an outer loop. The inner loop calculates the element x i The posterior probability of each time slot state, the outer loop completes the update of the posterior probability of the time slot state of all elements of x through the update of pseudo noise.

[0107] Based on the soft information of all subframe time slot states, the receiver needs to complete the soft demodulation of the transmission mode codeword activity detection and the arrangement constellation symbol:

[0108] Based on the encoding method and the sending method, the subframe tail has J p Active transmission modes need to be detected, and the single-slot status soft information Represents the posterior probability of the idle state, combined with the estimated soft information of all time slot states, to define the active probability matrix

[0109]

[0110] in represents an element with r rows and c columns, Represents the idle state posterior probability of the rth element in the cth time slot. Active detection is performed on different segments of each row of the active probability matrix. The transmission mode sequence codeword with the maximum sum of active posterior probabilities will be determined as the active transmission mode sequence. The determination process can be equivalent to the inner product of the active probability matrix and the pre-stored transmission mode sequence codebook.

[0111]

[0112] Based on the transmission mode detection result and the estimated a posteriori probability of the constellation point symbol of the corresponding arrangement position, the bit likelihood soft information (LLR, Log-Likelihood Ratio) can be obtained. Taking Quadrature Phase Shift Keying (QPSK, Quadrature PhaseShift Keying) as an example, the modulation order is Q=4 and the time slot state is One of the constellation point symbols carries two bits of information, namely Based on this example, the bit likelihood soft information can be calculated

[0113]

[0114] Based on the calculated bit likelihood soft information, the receiving end performs forward error correction decoding of the channel coding. Based on the results of the forward error correction channel coding soft decoding, the receiving end performs successive interference cancellation (SIC):

[0115] The receiving end performs bit judgment and parity check on the forward error correction decoding result of the channel coding. The bit data that passes the parity check is re-encoded and modulated to form an elimination signal matrix, denoted as X SIC , before serial interference cancellation, the channel estimate is corrected using the cancellation signal matrix

[0116]

[0117] Where Y is the subframe received signal, H SIC is the corrected channel estimate, since X SIC The channel length is longer than the subframe header signal, and more observations will lead to relatively accurate channel estimation.

[0118] Y=YH SIC X SIC

[0119] The receiving end repeatedly performs the above solving operation until no bit data that can pass the parity check can be generated.

[0120] An electronic device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the method for multiple access transmission without user identification and shared codebook approaching the theoretical capacity under a finite field is implemented.

[0121] A computer-readable storage medium stores computer instructions, characterized in that when the computer instructions are executed by a processor, the method for multiple access transmission without user identification and shared codebook approaching the theoretical capacity under a finite field is implemented.

[0122] Compared with the prior art, the main feature of the present invention is that the transmission energy efficiency is higher, only a small part of the encoded signal consumes energy, and the recovery of most data bits does not require additional energy consumption. At the same time, the complexity of the present invention is lower than that of similar schemes. In addition, since there are fewer transmission symbols entering the channel, the higher level of unit transmission energy makes the present invention have extremely strong anti-interference performance. Therefore, the random multiple access of the present invention under a finite field can achieve a system performance close to the theoretical capacity.

[0123] The present invention has the beneficial effects:

[0124] 1. The transmission method of the present invention has the characteristics of being simple and easy to construct, having high transmission efficiency and a small amount of signal transmission;

[0125] 2. The transmission method of the present invention has the characteristics of strong anti-interference ability. Since the amount of transmitted signals is small, the unit energy of the transmitted signals is high under the same transmission energy, and it has excellent ability to resist background noise and crosstalk between users;

[0126] 3. The transmission method of the present invention has the characteristics of low pilot signal collision;

[0127] 4. The transmission method of the present invention has the characteristics of relatively low complexity;

[0128] 5. The transmission scheme of the present invention has the characteristics of low power consumption, and the system capacity is much higher than similar schemes. It has the potential to reach the theoretical capacity under finite domain when equipped with a large-scale antenna system;

[0129] The transmission scheme of the present invention has the characteristics of low power consumption, and the system capacity is much higher than similar schemes. It has the potential to reach the theoretical capacity under finite domain when equipped with a large-scale antenna system. Under a fixed number of users, the present invention requires a lower bit signal-to-noise ratio to achieve a certain system error probability, such as Figure 6 As shown, the ordinate represents the user bit signal-to-noise ratio required for the system error rate not to exceed 0.05 under a certain number of active users. When the number of antennas is 50, the energy consumption of the present invention is the lowest within 600 users, and when the number of antennas is 200

[0130] At the same time, the present invention is close to the theoretical limit, demonstrating its characteristics of low energy consumption and high capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0131] Figure 1 A schematic diagram of the encoding method and the sending method of the present invention;

[0132] Figure 2 A schematic diagram of a receiving end of the decoding method of the present invention;

[0133] Figure 3 This is a comparison diagram of the frame error rate caused by the collision of pilot signals in multi-subframe transmission of the present invention and in normal non-subframe transmission;

[0134] Figure 4 This is a comparison chart of the computational complexity of the present invention and similar solutions;

[0135] Figure 5 Comparison chart of the unit energy of the transmitted signal between the present invention and similar solutions;

[0136] Figure 6 The figure is a comparison chart of the system capacity between the present invention and similar solutions. DETAILED DESCRIPTION

[0137] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the present invention by those skilled in the art all fall within the scope defined by the claims attached to the present invention.

[0138] Example 1: See Figure 1 , Figure 2 , a method for transmitting multiple accesses without user identification and shared codebooks (URA) approaching the theoretical capacity under a finite field, a method for encoding, transmitting and decoding source bit data for transmitting multiple accesses without user identification and shared codebooks;

[0139] 1) The encoding method comprises:

[0140] Source bit data and its division and encoding method;

[0141] Pre-stored spreading sequence codebook and transmission mode codebook;

[0142] The source bit data is divided and encoded into a subframe selection bit sequence, a preamble selection bit sequence, a transmission mode selection bit sequence, and a sending bit sequence, and corresponding encoding is completed respectively;

[0143] Through the subframe selection bit sequence, the user selects the subframe position for sending information;

[0144] Through the leading selection bit sequence, the user selects the corresponding spreading sequence codeword from the pre-stored spreading sequence codebook;

[0145] Through the transmission mode selection bit sequence, the user selects multiple transmission modes from a pre-stored transmission mode codebook;

[0146] The transmission bit sequence is channel coded and constellation point modulated, and is arranged by a plurality of transmission modes selected by the transmission mode selection bit sequence. After the arrangement is completed, channel transmission is completed according to a preset transmission method;

[0147] 2) The sending method includes:

[0148] A channel with a fixed channel usage under a finite field is divided into a plurality of subframe positions;

[0149] The selected spread spectrum sequence codeword is located at the head of the subframe, and together with the constellation point symbol arranged in multiple transmission modes at the tail of the subframe, constitutes a complete subframe;

[0150] Complete signal transmission based on the selected subframe position;

[0151] Based on the subframe selection bit sequence, only signals of some users are superimposed at the subframe position in each subframe;

[0152] The receiving end receives all subframe signals under the finite field, and based on the set decoding method, completes the recovery of the source data for each subframe one by one;

[0153] 3) The decoding method for recovering the source data includes (the signal recovery method for each subframe is the same):

[0154] Estimating the number of active users in a subframe based on the transmitted signal energy and noise statistics;

[0155] Based on the multi-user spread spectrum sequence codeword signal superimposed on the subframe header, the spread spectrum sequence codeword activity detection and the corresponding channel state information estimation are completed;

[0156] Based on the channel state information estimation, soft demodulation of time slot subframe state information is completed;

[0157] Based on the soft demodulation time slot subframe state information, complete the transmission mode active detection and corresponding constellation point soft demodulation;

[0158] Calculate the bit likelihood soft information based on the transmission mode active detection result and the constellation point soft demodulation information;

[0159] Based on the bit likelihood soft information, performing forward error correction decoding of the channel coding;

[0160] Based on the result of the forward error correction decoding, performing a parity check on the decoded data sequence;

[0161] Based on the parity check result, serial interference elimination is performed, and the signal that has undergone the encoding method and transmission method again is removed from the received signal, and the above decoding method is repeated until there is no data sequence that passes the parity check.

[0162] Specifically:

[0163] For the encoding method:

[0164] The total channel usage in the finite domain is represented by L, the amount of source bit data is B, and the number of active users per antenna is K a , the number of antennas at the receiving end is M.

[0165] The source bit data is divided into B ck ,B pn ,B p ,B c , respectively selecting a bit sequence for the subframe, selecting a bit sequence for the preamble, selecting a bit sequence for the transmission mode, and sending a bit sequence. ck The bit data value selects the subframe position, so the total channel usage of the finite field needs to be divided into subframes, the subframe header is L p and tail length L c , if the subframe lengths are the same, then the constraint is satisfied

[0166]

[0167] Due to the randomness of subframe position selection, the number of active users at a single subframe position is given by Indicates; through the B pn Bit Data Selection J p transmission mode codewords, determine the subsequent arrangement mode; through the B p The bit data value selects the spread spectrum sequence codeword, so the spread spectrum sequence codebook needs to have Spread spectrum sequence codewords, define the spread spectrum sequence codebook as

[0168]

[0169] The selected spreading sequence codeword is determined by Indicates; said B c Bits of data need to go through channel coding, constellation point symbol modulation and transmission mode arrangement. The channel coding rate is expressed as R c The constellation point symbol modulation order is represented by Q. Therefore, after channel coding and symbol modulation, the number of constellation point symbols that need to be arranged is

[0170]

[0171] According to the above encoding method, the transmission mode codebook can be defined as

[0172]

[0173] The total number of transmission mode codebooks is transmission mode codewords, each of which has only S non-zero elements. The position of the non-zero element indicates the position of the constellation point symbol, and the position of the zero element indicates that there is no transmission signal. p The tail of the subframe after the transmission mode is arranged is Here is an example of how to arrange the constellation points according to the transmission mode codeword. If there is a transmission mode codeword [0,1,0,1,0,0] and a constellation point symbol [s1,s2], the following combinations can be obtained after arrangement: [0,s1,0,s2,0,0] or [0,s1,0,s2,0,0], that is, the order of symbols after arrangement can be flexibly set.

[0174] For the sending method:

[0175] The signal of a single subframe superposition can be expressed as The superposition signal of multi-user spread spectrum sequence codeword signal (including additive Gaussian white noise) is: The specific expression of the frame header receiving signal is:

[0176]

[0177] in represents a user's spreading sequence codeword vector, is the channel coefficient vector of a certain user, and the additive Gaussian white noise in the frame header is Follow the mean 0 variance σ 2 Cyclic symmetric complex Gaussian distribution; Multiple users have multiple transmission modes arranged in the constellation point symbol superposition signal

[0178] (including additive white Gaussian noise) is The specific expression of the received signal at the end of the frame is:

[0179]

[0180] in is the constellation point signal arranged in multiple transmission modes, and the additive Gaussian white noise at the end of the frame is Follow the mean 0 variance σ 2 The cyclically symmetric complex Gaussian distribution of . At the same time, the transmission energy constraint of the signal is determined by the bit signal-to-noise ratio (energy-per-bit), which is defined as

[0181]

[0182] The total signal transmission energy constraint of a single user is P, E s is the unit channel usage energy, and the power allocation coefficient α is defined as the proportion allocated to a single user in the subframe header, that is, the single-user subframe header signal satisfies the energy constraint The energy constraint of the subframe tail signal is

[0183] For the decoding method:

[0184] The processing method for each subframe is the same, and the following is a detailed description of the received signal of a single subframe.

[0185] Due to the randomness of subframe position selection, the receiver needs to estimate the number of active users in each subframe.

[0186] The number of active users is calculated based on the energy constraint of the transmitted signal and the noise statistics. Make rounding estimates

[0187]

[0188] in is the average received signal energy of a single antenna. Number of active users That is equivalent to the number of active spreading sequence codeword sequences.

[0189] After estimating the signal reception energy, the receiver needs to complete the estimation of the channel state information:

[0190] The subframe header receiving signal can be equivalent to

[0191] Y p =AH+Z p

[0192] The channel matrix H has only The rows are non-zero vectors, and the rest are zero vectors; the non-zero vectors of the channel matrix represent the channel coefficients of the active spread spectrum sequence codewords; solving the channel coefficients can be equivalent to solving the compressed sensing problem, and many common methods can solve this type of problem. Here, according to the idea of ​​multi-antenna orthogonal matching pursuit (SOMP), the active detection of the spread spectrum sequence codewords and the corresponding channel state information estimation are performed according to the pre-stored common spread spectrum sequence codewords; in each cycle, SOMP selects the measurement matrix column with the largest correlation with the current residual and adds its index to the output list, that is, the active detection of the spread spectrum sequence codewords is completed;

[0193] The detected active spreading sequence codeword is used to estimate the channel coefficients and update the residual; the number of cycles can be set to The residual R can be initialized to the subframe header received signal, and the spread spectrum sequence codeword correlation / active detection is calculated as

[0194]

[0195] The sequence number of the active codeword is stored in In; the orthogonal projection is constructed by determining the active codeword sequence, let Then the residual is updated to

[0196]

[0197] in is the Moore-Penrose generalized inverse, and the sequence numbers of all active codewords are obtained through repeated iterations; the channel estimation corresponding to the active spreading sequence codeword can be completed in different ways, such as the channel coefficient estimation based on the minimum mean square error (MMSE) error criterion is

[0198]

[0199] After obtaining the estimated channel coefficients, the receiving end performs soft demodulation of the state information of the tail time slot of the subframe:

[0200] First, define the subframe time slot state for

[0201]

[0202] Where s0=0 is the idle state, {s1,…,s Q} is the active state, i.e. the constellation point symbol after arrangement,

[0203] is the energy constraint for a single constellation point symbol.

[0204] No.1 c The soft demodulation signal model of a time slot is:

[0205]

[0206] in Y c A column represents a single time slot received signal, and z is the corresponding additive Gaussian white noise. The soft demodulation method of the time slot status information is the same, and different time slots can be performed independently. The subsequent detailed description is for a single

[0207] Time slot signal processing. The time slot signal model after channel equalization can be obtained:

[0208]

[0209] in z can be equivalent to a matrix with zero mean and covariance Gaussian noise. State soft information demodulation aims to calculate the time slot state corresponding to each element in x The posterior probability of the state element in , Used to represent the element x to be estimated i ∈x and the posterior probability of each time slot state. To solve the element x i The state posterior probability is introduced, and the guidance vector The guidance vector has only one non-zero element 1 at the i-th position. After introducing the guidance vector, we can get

[0210]

[0211] The signals other than the target element (Target) are considered as pseudo noise Pseudo noise has a statistical mean matrix (Mean Matrix) E i , Covariance Matrix Ω i , Pseudo Covariance MatrixΞ i , considering interference as noise, the above statistics can be obtained by the following calculation

[0212]

[0213] Process variables ω i ,ξ j It can be obtained by the following calculation

[0214]

[0215] At the same time, the prior probability of each time slot state can be obtained through the encoding method and the sending method.

[0216]

[0217] After obtaining the above statistics, the fixed estimation element is a certain time slot state And calculate the signal residual in this state

[0218]

[0219] Based on this residual calculation, the likelihood value of the corresponding state can be calculated

[0220]

[0221] in Represent the real and imaginary parts of the complex number, respectively, and the process variable Λ i The noise statistics can be obtained

[0222]

[0223] After the above solution, the element x i The posterior probability of the time slot state can be calculated by the likelihood value

[0224]

[0225] The above time slot state soft information demodulation solution process is iterated repeatedly, divided into an inner loop and an outer loop. The inner loop calculates the element x i The posterior probability of each time slot state, the outer loop completes the update of the posterior probability of the time slot state of all elements of x through the update of pseudo noise.

[0226] Based on the soft information of all subframe time slot states, the receiver needs to complete the soft demodulation of the transmission mode codeword activity detection and the arrangement constellation symbol:

[0227] Based on the encoding method and the sending method, the subframe tail has J p Active transmission modes need to be detected, and the single-slot status soft information Represents the posterior probability of the idle state, combined with the estimated soft information of all time slot states, to define the active probability matrix

[0228]

[0229]

[0230] in represents an element with r rows and c columns, Represents the idle state posterior probability of the rth element in the cth time slot. Active detection is performed on different segments of each row of the active probability matrix. The transmission mode sequence codeword with the maximum sum of active posterior probabilities will be determined as the active transmission mode sequence. The determination process can be equivalent to the inner product of the active probability matrix and the pre-stored transmission mode sequence codebook.

[0231]

[0232] Based on the transmission mode detection result and the estimated a posteriori probability of the constellation point symbol of the corresponding arrangement position, the bit likelihood soft information (LLR, Log-Likelihood Ratio) can be obtained. Taking Quadrature Phase Shift Keying (QPSK, Quadrature PhaseShift Keying) as an example, the modulation order is Q=4 and the time slot state is One of the constellation point symbols carries two bits of information, namely Based on this example, the bit likelihood soft information can be calculated

[0233]

[0234] Based on the calculated bit likelihood soft information, the receiving end performs forward error correction decoding of the channel coding. Based on the results of the forward error correction channel coding soft decoding, the receiving end performs successive interference cancellation (SIC):

[0235] The receiving end performs bit judgment and parity check on the forward error correction decoding result of the channel coding. The bit data that passes the parity check is re-encoded and modulated to form an elimination signal matrix, denoted as X SIC , before serial interference cancellation, the channel estimate is corrected using the cancellation signal matrix

[0236]

[0237] Where Y is the subframe received signal, H SIC is the corrected channel estimate, since X SIC The channel length is longer than the subframe header signal, and more observations will lead to relatively accurate channel estimation.

[0238] Y=YH SIC X SIC

[0239] The receiving end repeatedly performs the above solving operation until no bit data that can pass the parity check can be generated.

[0240] Embodiment 2: The channel usage of the finite domain can be flexibly adjusted. Taking a single carrier of 2GHZ as an example, the coherence time ranges from 1ms to 45ms (depending on the moving speed of the device transmitter 3km / h-120km / h). At the same time, in an outdoor environment, when matching the coherence bandwidth, the sampling frequency of the receiving device is usually between 100kHZ-500kHZ. Therefore, the channel usage of the finite domain can be flexibly set within the range of 100-20,000. The consistency of spectrum efficiency must be maintained when comparing solutions. The frame error rate (including false alarm rate and missed detection rate) is usually used as a performance evaluation indicator for a shared codebook multiple access system without user identification.

[0241] Number of active users: 100, 500, 1000;

[0242] Multi-subframe transmission B ck =4, With no subframe transmission;

[0243] Figure 3This is a comparison chart of the frame error rate caused by the collision of pilot signals in the multi-subframe transmission of the present invention and in the normal transmission without subframes; the comparison result shows that the multi-subframe transmission can significantly reduce the frame error rate caused by the collision of pilot signals, reducing the collision frame error rate by about 100 to 1000 times.

[0244] Embodiment 3:

[0245] The amount of source bit data is B = 470;

[0246] The channel usage is L = 15040, and the spectrum efficiency is consistent with the theoretical boundary of the comparison scheme, both of which are 0.0312;

[0247]

[0248] The source bit data is divided into B p =14,B c =36,B ck =4,B pn =416;

[0249] The number of subframes is The subframe length is L / J=940, and the subframe header length and tail length are L p =172,L c =768;

[0250] The energy distribution coefficient is set to α = 0.1;

[0251] The spreading sequence codebook size is Generated by an undersampled discrete Fourier transform matrix (DFT), which complies with energy constraints;

[0252] The channel coding uses the 5GNR Polar code with a length of 256 and a 24-bit cyclic redundancy check (CRC). The 24-CRC generating polynomial is x 24 +x 23 +x 21 +x 20 +x 17 +x 15 +x 13 +x 12 +x 8 +x 4 +x 2 +x+1;

[0253] The constellation point modulation adopts quadrature phase shift keying QPSK;

[0254] The number of transmission modes is J p =32, that is, every Bpn / J p = 13 bits to select a transmission mode, a total of 32, the transmission mode codebook size is The transmission mode codeword length is L c / J p =24, the number of non-zero elements in the transmitted codeword is 4;

[0255] Figure 4 This is a comparison chart of the computational complexity of the present invention and similar solutions; the result shows that the present invention has a relatively low level of system computational complexity among similar solutions;

[0256] Figure 5 This is a comparison chart of the unit energy of the transmitted signal of the present invention and similar solutions. The unit energy of the transmitted signal is defined as the single-user transmission energy constraint divided by the number of transmitted units, that is, (transmitted energy) / (number of preamble selection bits + number of transmitted constellation point symbols). The result shows that the present invention has a higher unit energy of the transmitted signal than similar solutions, and therefore has a higher ability to resist background noise and interference under the same energy constraint;

[0257] Figure 6 This is a comparison chart of the system capacity of the present invention and similar solutions, comparing the bit signal-to-noise ratio (in decibels dB) required to achieve a system frame error rate of 0.05 under different total active user numbers. The results show that when the receiving end is equipped with 50 antennas, the solution of the present invention can obtain the theoretical achievable capacity under a total number of 100 to 400 active users; when the receiving end is equipped with 200 antennas, the solution of the present invention can basically maintain the theoretical achievable capacity under a total number of 100 to 1000 active users. It proves that the present invention has low power consumption and high capacity system performance compared with similar solutions, and has the potential to approach the theoretical capacity under a finite domain. It should be noted that the above embodiments are not intended to limit the scope of protection of the present invention, and equivalent changes or substitutions made on the basis of the above technical solutions fall within the scope of protection of the claims of the present invention.

Claims

1. A method for multiple access transmission with shared codebook without user identification that approaches theoretical capacity under finite fields, characterized in that: A source bit data encoding method, a sending method and a decoding method for multiple access transmission without user identification and shared code book.

2. The method for multiple access transmission without user identification and shared codebook approaching theoretical capacity under finite field according to claim 1, characterized in that: The encoding method comprises: Source bit data and its division and encoding method; Pre-stored spreading sequence codebook and transmission mode codebook; The source bit data is divided and encoded into a subframe selection bit sequence, a preamble selection bit sequence, a transmission mode selection bit sequence, and a sending bit sequence, and corresponding encoding is completed respectively; Through the subframe selection bit sequence, the user selects the subframe position for sending information; Through the leading selection bit sequence, the user selects the corresponding spreading sequence codeword from the pre-stored spreading sequence codebook; Through the transmission mode selection bit sequence, the user selects multiple transmission modes from a pre-stored transmission mode codebook; The transmission bit sequence is channel coded and constellation point modulated, and is arranged through multiple transmission modes selected by the transmission mode selection bit sequence. After the arrangement is completed, channel transmission is completed according to a preset transmission method.

3. The method for multiple access transmission without user identification and shared codebook approaching theoretical capacity under finite field according to claim 2, characterized in that: In the encoding method, The total channel usage in the finite domain is represented by L, the amount of source bit data is B, and the number of active users per antenna is K a , the number of antennas at the receiving end is M, The source bit data is divided into B ck , B pn , B p , B c , respectively, selecting a bit sequence for the subframe, selecting a bit sequence for the preamble, selecting a bit sequence for the transmission mode, sending a bit sequence, and passing B ck The bit data value selects the subframe position, so the total channel usage of the finite field needs to be divided into subframes, the subframe header is L p and tail length L c , if the subframe lengths are the same, then the constraint is satisfied Due to the randomness of subframe position selection, the number of active users at a single subframe position is given by Indicates; through the B pn Bit Data Selection J p transmission mode codewords, determine the subsequent arrangement mode; through the B p The bit data value selects the spread spectrum sequence codeword, so the spread spectrum sequence codebook needs to have Spread spectrum sequence codewords, define the spread spectrum sequence codebook as The selected spreading sequence codeword is determined by Indicates; said B c Bits of data need to go through channel coding, constellation point symbol modulation and transmission mode arrangement. The channel coding rate is expressed as R c The constellation point symbol modulation order is represented by Q. Therefore, after channel coding and symbol modulation, the number of constellation point symbols that need to be arranged is According to the above encoding method, the transmission mode codebook can be defined as The transmission mode codebook has a total of transmission mode codewords, each of which has only S non-zero elements. The position of the non-zero element indicates the position of the constellation point symbol, and the position of the zero element indicates that there is no transmission signal. p The tail of the subframe after the transmission mode is arranged is express.

4. The method for multiple access transmission without user identification and shared codebook approaching theoretical capacity under finite field according to claim 1, characterized in that: The sending method comprises: A channel with a fixed channel usage under a finite field is divided into a plurality of subframe positions; The selected spread spectrum sequence codeword is located at the head of the subframe, and together with the constellation point symbol arranged in multiple transmission modes at the tail of the subframe, constitutes a complete subframe; Complete signal transmission based on the selected subframe position; Based on the subframe selection bit sequence, only signals of some users are superimposed at the subframe position in each subframe; The receiving end receives all subframe signals in the finite field, and based on the set decoding method, recovers the source data for each subframe one by one.

5. The method for multiple access transmission without user identification and shared codebook approaching theoretical capacity under finite field according to claim 4, characterized in that: In the sending method, The signal of a single subframe superposition is represented as The superposition signal of multi-user spread spectrum sequence codeword signal (including additive Gaussian white noise) is: The specific expression of the frame header receiving signal is: in represents the spreading sequence codeword vector of a certain user, is the channel coefficient vector of a certain user, and the additive Gaussian white noise in the frame header is Follow the mean 0 variance σ 2 Cyclic symmetric complex Gaussian distribution; Multiple users have multiple transmission modes arranged in the constellation point symbol superposition signal (including additive white Gaussian noise) is The specific expression of the received signal at the end of the frame is: in is the constellation point signal arranged in multiple transmission modes, and the additive Gaussian white noise at the end of the frame is Follow the mean 0 variance σ 2 The cyclically symmetric complex Gaussian distribution of the signal is determined by the bit signal-to-noise ratio (energy-per-bit), which is defined as The total signal transmission energy constraint of a single user is P, E s is the unit channel usage energy, and the power allocation coefficient α is defined as the proportion allocated to a single user in the subframe header, that is, the single-user subframe header signal satisfies the energy constraint The signal at the end of the subframe satisfies the energy constraint of || 6. The method for multiple access transmission without user identification and shared codebook approaching theoretical capacity under finite field according to claim 1, characterized in that: The decoding method for source data recovery includes: Estimating the number of active users in a subframe based on the transmitted signal energy and noise statistics; Based on the multi-user spread spectrum sequence codeword signal superimposed on the subframe header, the spread spectrum sequence codeword activity detection and the corresponding channel state information estimation are completed; Based on the channel state information estimation, soft demodulation of time slot subframe state information is completed; Based on the soft demodulation time slot subframe state information, complete the transmission mode active detection and corresponding constellation point soft demodulation; Calculate the bit likelihood soft information based on the transmission mode active detection result and the constellation point soft demodulation information; Based on the bit likelihood soft information, performing forward error correction decoding of the channel coding; Based on the result of the forward error correction decoding, performing a parity check on the decoded data sequence; Based on the parity check result, serial interference elimination is performed, and the signal that has undergone the encoding method and transmission method again is removed from the received signal, and the above decoding method is repeated until there is no data sequence that passes the parity check.

7. The method for multiple access transmission without user identification and shared codebook approaching theoretical capacity in a finite field according to claim 6, characterized in that: In the decoding method, Due to the randomness of subframe position selection, the receiving end needs to estimate the number of active users in each subframe, and estimate the number of active users based on the energy constraint of the transmitted signal and the noise statistics. Make rounding estimates in is the average received signal energy of a single antenna, the number of active users That is equivalent to the number of active spreading sequence codeword sequences, After estimating the signal reception energy, the receiver needs to complete the estimation of the channel state information: The subframe header received signal is equivalent to AND p =AH+Z p The channel matrix H has only The rows are non-zero vectors, and the rest are zero vectors; the non-zero vectors of the channel matrix represent the channel coefficients of the active spreading sequence codewords; In each loop, SOMP selects the measurement matrix column with the largest correlation with the current residual and adds its index to the output list, completing the active detection of the spreading sequence codeword; the detected active spreading sequence codeword is used for channel coefficient estimation and residual update; the number of loops can be set to The residual R can be initialized to the subframe header received signal, and the spread spectrum sequence codeword correlation / active detection is calculated as The sequence number of the active codeword is stored in In; the orthogonal projection is constructed by determining the active codeword sequence, let Then the residual is updated to in is the Moore-Penrose generalized inverse, and the sequence numbers of all active codewords are obtained through repeated iterations; the channel coefficient is estimated based on the minimum mean square error (MMSE) error criterion as follows: After obtaining the estimated channel coefficients, the receiving end performs soft demodulation on the state information of the subframe tail time slot: First, define the subframe time slot state for Where s0=0 is the idle state, {s1,...,s Q } is the active state, i.e. the constellation point symbol after arrangement, is the single constellation point symbol energy constraint, No.1 c The soft demodulation signal model of a time slot is: in Y c A column represents a single time slot received signal, z is the corresponding additive Gaussian white noise, the time slot state information soft demodulation method is the same, different time slots can be performed independently, the subsequent detailed description of the single time slot signal processing, the time slot signal model after channel equalization can be obtained: in z is equivalent to having zero mean and covariance matrix Gaussian noise, state soft information demodulation aims to calculate the time slot state corresponding to each element in x The posterior probability of the state element in , Used to represent the element x to be estimated i ∈x and the posterior probability of each time slot state, to solve the element x i The state posterior probability is introduced, and the guidance vector The guidance vector has only one non-zero element 1 at the i-th position. After introducing the guidance vector, we can get The signals other than the target element (Target) are considered as pseudo noise Pseudo noise has a statistical mean matrix (Mean Matrix) E i , Covariance Matrix Ω i , Pseudo Covariance MatrixΞ i , considering interference as noise, the above statistics can be obtained by the following calculation Process variables It can be obtained by the following calculation At the same time, the prior probability of each time slot state is obtained through the encoding method and the sending method. After obtaining the above statistics, the fixed estimation element is a certain time slot state And calculate the signal residual in this state Based on this residual calculation, the likelihood value of the corresponding state can be calculated in Represent the real and imaginary parts of the complex number, respectively, and the process variable Λ i The noise statistics can be obtained After the above solution, the element x i The posterior probability of the time slot state can be calculated by the likelihood value The above time slot state soft information demodulation solution process is iterated repeatedly, divided into an inner loop and an outer loop. The inner loop calculates the element x i The posterior probability of each time slot state, the outer loop completes the update of the posterior probability of the time slot state of all elements of x through the update of pseudo noise, Based on the soft information of all subframe time slot states, the receiver needs to complete the soft demodulation of the transmission mode codeword activity detection and the arrangement constellation symbol: Based on the encoding method and the transmission method, there is J at the end of the subframe. p Active transmission modes need to be detected, and the single-slot status soft information Represents the posterior probability of the idle state, combined with the estimated soft information of all time slot states, to define the active probability matrix in represents an element with r rows and c columns, Represents the idle state posterior probability of the rth element in the cth time slot. Active detection is performed on different segments of each row of the active probability matrix. The transmission mode sequence codeword with the maximum sum of active posterior probabilities will be determined as the active transmission mode sequence. The determination process can be equivalent to the inner product of the active probability matrix and the pre-stored transmission mode sequence codebook. Based on the transmission mode detection result and the estimated a posteriori probability of the constellation point symbol of the corresponding arrangement position, the bit likelihood soft information (LLR, Log-Likelihood Ratio) can be obtained. Taking Quadrature Phase Shift Keying (QPSK, Quadrature Phase ShiftKeying) as an example, the modulation order is Q=4 and the time slot state is One of the constellation point symbols carries two bits of information, namely Based on this example, the bit likelihood soft information can be calculated Based on the calculated bit likelihood soft information, the receiver performs forward error correction decoding of the channel coding. Based on the results of soft decoding of forward error correction channel coding, the receiving end performs successive interference cancellation (SIC): The receiving end performs bit judgment and parity check on the forward error correction decoding result of the channel coding. The bit data that passes the parity check is re-encoded and modulated to form an elimination signal matrix, denoted as X SIC , before serial interference cancellation, the channel estimate is corrected using the cancellation signal matrix Where Y is the subframe received signal, H SIC is the corrected channel estimate, since X SIC The channel length is longer than the subframe header signal. More observations will lead to relatively accurate channel estimation. The receiving end performs serial interference. Y=Y-H SIC X SIC The receiving end repeats the above solution operation until no bits that can pass the parity check can be generated. data.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the shared codebook multiple access transmission method without user identification and approaching the theoretical capacity under a finite field as described in any one of claims 1 to 7 above is implemented.

9. A computer-readable storage medium having computer instructions stored thereon, characterized in that: When the computer instructions are executed by a processor, the method for multiple access transmission without user identification and shared codebook approaching theoretical capacity in a finite field as described in any one of claims 1 to 7 is implemented.

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