A multi-beam disparity layered modulation multiple access method

Abstract

The application discloses a multi-beam disparity layered modulation multiple access method, wherein a transmitting end splits user channel coded bit data into shared parts and private parts according to actual channel conditions of each user; the transmitting end superimposes and transmits the pre-coded phase-rotated data, so that constellation point phases of a receiving end are aligned; the receiving end calculates equivalent channel coefficients and receiving end constellation Euclidean distance parameters based on receiving end channel state information, and performs once equalization and I / Q path separation processing on a received signal; the receiving end decodes bit streams distributed in shared layers and all bit streams in private layers, calculates log likelihood ratios of all bit streams, and then sends the log likelihood ratios into a channel decoder to recover source bit data of each user. The method can avoid interference of shared part data on private part data without serial interference cancellation in some working modes, and realizes high user rate.

Description

Technical Field

[0001] This invention relates to wireless communication systems, and more particularly to a multi-beam parallax hierarchical modulation multiple access method. Background Technology

[0002] Limited by finite spectrum resources, base stations in wireless communication systems typically need to divide the wireless spectrum into time-frequency resource blocks and allocate them to multiple users to provide simultaneous service. Downlink multiple access (MKA) technology is a key technology for addressing this issue. Existing MKA technologies can be mainly divided into orthogonal MKA and non-orthogonal MKA technologies. Orthogonal MKA avoids inter-user interference by allocating non-overlapping time-frequency resource blocks orthogonally to each user, thus reducing the complexity of user receivers. However, the orthogonal resource allocation method also results in lower system spectral efficiency, making it difficult to meet the growing service demands. In contrast, non-orthogonal MKA allows multiple users to overlap on the same time-frequency resource block and uses more complex signal processing techniques to address the impact of inter-user interference on user rates, thereby further improving system spectral efficiency. For example, the 3GPP TR36.859 protocol has specified several key implementation methods for downlink multi-user overlapping transmission (hereinafter referred to as MUST technology). In this method, several users with different channel gains form a transmission group, and users within the group are superimposed after using their respective constellation mappings and configuring different powers; or bit mapping is performed on a unified constellation diagram. In this method, serial interference cancellation is an essential receiving technique. Users with better channel conditions within a group need to first decode and reconstruct the signals of users with poorer channel conditions, then cancel them out in the received signal before receiving their own. This method increases the receiving complexity under non-orthogonal receiving conditions, thus hindering the further deployment and promotion of this technique in practical systems.

[0003] As the number of base station antennas increases, spatial division multiple access (SDMA) technology brings significant spectral efficiency gains by distinguishing user data streams in the spatial domain. Simultaneously, because user data is spatially separated, the receiver can maintain low complexity. However, when user distribution is dense and channel spatial correlation is strong, this method experiences significant performance degradation. In recent years, a new multiple access technology called rate splitting multiple access (RSMA) has been proposed. Based on the rate splitting concept, it integrates existing mainstream multiple access technologies, demonstrating performance advantages in spectral efficiency, energy efficiency, and robustness to channel state information. However, it also requires serial interference cancellation at the receiver to partially decode interference in order to achieve relatively ideal performance, thus also suffering from high receiver complexity. Summary of the Invention

[0004] The purpose of this invention is to provide a multi-beam parallax hierarchical modulation multiple access method. This method enables users to avoid interference between shared data and private data without serial interference cancellation in certain operating modes, and achieves high user rates using only a simple receiving processing procedure.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A multi-beam parallax hierarchical modulation multiple access method, the method comprising:

[0007] Step 1: The transmitter splits the bit data encoded by each user's channel into a shared part and a private part according to the actual channel conditions of each user, and maps them together on the hierarchical constellation diagram according to a specific bit stream layering and allocation scheme.

[0008] Step 2: After obtaining the symbols corresponding to the shared layer and each private layer through joint mapping, the transmitter precodes their phases and then superimposes and transmits them.

[0009] Step 3: Based on the joint mapping and phase-aligned precoding design of the transmitter, the receiver calculates the equivalent channel coefficients and the Euclidean distance parameters of the receiver constellation diagram based on the receiver channel state information, and performs equalization and I / Q path separation processing on the received signal.

[0010] Step 4: Corresponding to the bit stream allocation result at the transmitting end, the receiving end decodes the bit streams allocated in the shared layer and all bit streams in the private layer. After calculating the log-likelihood ratio of all bit streams, it sends them to the channel decoder to recover the bit data of each user source.

[0011] As can be seen from the technical solution provided by the present invention, the above method enables users to avoid interference between shared data and private data without serial interference cancellation in certain working modes. A high user rate can be achieved with only a simple receiving and processing procedure, which has good application prospects. Attached Figure Description

[0012] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a schematic diagram of the multi-beam parallax hierarchical modulation multiple access method provided in an embodiment of the present invention;

[0014] Figure 2This is a schematic diagram of the transceiver constellation structure in a two-user scenario, as illustrated in the example of this invention. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments, and do not constitute a limitation of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0016] like Figure 1 The diagram shown is a flowchart of a multi-beam parallax hierarchical modulation multiple access method provided in an embodiment of the present invention. The method includes:

[0017] Step 1: The transmitter splits the bit data encoded by each user's channel into a shared part and a private part according to the actual channel conditions of each user, and maps them together on the hierarchical constellation diagram according to a specific bit stream layering and allocation scheme.

[0018] In this step, the transmitter processes the source bit data of each user through independent channel coding according to the actual channel conditions of each user to obtain the corresponding encoded bits. Then, the encoded bits of each user are split into two parts: shared layer bits and private layer bits. The shared layer bits of each user are combined together to form the total shared layer bits, while the private layer bits of each user are processed separately.

[0019] Taking a two-user system as an example, the encoded bits of the two users are split to form a shared layer and two parallel private layers. The shared layer is composed of partial bits from the two users, while each private layer contains only bit data from one user.

[0020] Shared and private layer bit data are allocated to different bit streams on a given constellation diagram at the transmitting end, and the number of bit streams allocated to each layer is optimized according to the actual scenario.

[0021] After splitting the encoded bits of each user, the shared layer bits are first mapped to shared layer symbols via Gray mapping. Bits from different users in the shared layer are carried on different bitstreams, i.e., modulated into shared layer symbols s0 in the form of bitstream demultiplexing. Simultaneously, the transmitter employs a hierarchical quadrature amplitude modulation (H-QAM) constellation diagram. Compared to a general uniform QAM constellation diagram, the main difference lies in the adjustable Euclidean distance parameters of each bitstream in the constellation diagram. Therefore, the transmitter needs to optimize the Euclidean distance parameters corresponding to each bitstream in the constellation diagram based on the user channel conditions during symbol mapping. For a given constellation diagram Euclidean distance parameter, the shared layer symbol mapping process is expressed as follows:

[0022]

[0023] in Represents the real part of the symbol; The symbol represents the imaginary part; the superscripts i and q represent the I and Q paths respectively; κ and l represent the index numbers of the bit streams on the I and Q paths respectively; m0 and n0 represent the number of bit streams on the I and Q paths corresponding to the shared layer. These represent the j-th bit streams on the I and Q paths of the shared layer, respectively. Then, these represent the Euclidean distance parameters on the constellation diagram corresponding to the j-th bit stream on the I and Q paths in the shared layer, respectively;

[0024] After the shared layer symbol s0 is determined, the private layer needs to adjust its mapping rules according to the bit values ​​of the shared layer to ensure that the composite constellation diagram of the shared layer and the private layer maintains the Gray mapping structure. For the private layer symbol s0 corresponding to the k-th user... k The joint mapping process is expressed as:

[0025]

[0026] Where m k ,n k These represent the number of I-path and Q-path bitstreams in the private layer corresponding to the k-th user, respectively; These represent the j-th bit streams on the I and Q paths in the private layer corresponding to the k-th user, respectively. These represent the Euclidean distance parameters between the j-th bit streams on the I and Q paths in the private layer corresponding to the k-th user;

[0027] For ease of subsequent representation, the energy of each transmitted symbol has been normalized, i.e., we have

[0028] Step 2: After obtaining the symbols corresponding to the shared layer and each private layer through joint mapping, the transmitter precodes their phases and then superimposes and transmits them.

[0029] In this step, through the transmitter design described in steps 1 and 2, the constellation parallax phenomenon unique to this invention appears at each receiver, that is, the shared layer and private layer constellations are aligned and superimposed to form a new hierarchical constellation diagram.

[0030] In this step, after obtaining the symbols corresponding to the shared layer and each private layer through joint mapping, the transmitted signal is represented as follows:

[0031]

[0032] Where K represents the number of users; s0, s k These represent the shared layer symbol and the k-th private layer symbol, respectively, where the k-th private layer corresponds to the private layer of the k-th user; p0, p k These represent the precoding vectors for the shared layer symbol and the k-th private layer symbol, respectively.

[0033] To eliminate interference between private layers, the precoding vectors of each private layer symbol are configured to satisfy orthogonality constraints:

[0034]

[0035] in This represents the conjugate transpose of the k-th user channel vector. In specific implementations, other compromise methods, such as minimum mean square error (MMSE), can also be used to retain a certain degree of interference between private layer symbols, but this does not prevent the receiver from using a simple receiving method to complete the reception. The remaining private stream interference is treated as noise.

[0036] Furthermore, since the shared layer and each private layer are transmitted on different beams, the precoding vectors must also satisfy phase alignment constraints to ensure that the shared layer symbols received by each user are in phase with the required private layer symbols.

[0037]

[0038] Where ∠(·) represents the phase operation of taking a complex number;

[0039] In practice, the precoding vector p0 of the shared layer symbol can be determined first, and then the precoding vector of each private layer symbol can be rotated in a certain phase to satisfy the constraint condition.

[0040] The transmitter precodes the shared layer and each private layer symbol and then superimposes them for transmission. The shared layer portion of all users is transmitted in the form of bitstream multiplexing within the same symbol, while the remaining private layer portion of each user is transmitted separately on a private layer symbol. Each user only receives the shared layer symbol stream and the private layer symbol stream required by itself. The received signal y of the k-th user...k Represented as:

[0041]

[0042] Where n k Let σ represent the additive white Gaussian noise at the receiver for the k-th user. 2 ;

[0043] Due to the phase rotation operation at the transmitting end, the received signal in equation (6) can be equivalently expressed as:

[0044]

[0045] in

[0046] Further define the normalized synthesized receive symbol for the k-th user. Then, formula (7) can be further simplified to:

[0047]

[0048] in It is the equivalent channel gain for the k-th user;

[0049] Further analysis of the normalized synthesized received symbols for each user It can be viewed as samples from the I and Q paths, each with m0+m. k and n0+n k The H-QAM constellation diagram for each bit stream, and the correspondence between each bit stream and the bit stream at the transmitting end are as follows:

[0050]

[0051] in These represent the κ-th and l-th bitstreams received by the k-th user on the I and Q paths, respectively. The Euclidean distance parameters for each bitstream are:

[0052]

[0053] in These represent the Euclidean distance parameters corresponding to the κ-th and l-th bitstreams received by the k-th user on the I and Q paths, respectively;

[0054] Combining formulas (7) and (10), we can obtain:

[0055]

[0056] As can be seen from the above analysis, thanks to the transmitter design, each receiver can only observe its own private layer, while all users can observe the same shared layer. Moreover, the shared layer and private layer observed by each user exactly constitute a unique hierarchical constellation diagram that satisfies the Gray mapping structure. This constitutes the constellation diagram parallax phenomenon unique to this invention. Under this hierarchical constellation diagram, each user only needs to complete data reception with the complexity of a single-user receiver, without the need to use serial interference cancellation to eliminate interference between multiple beams, thereby reducing the complexity of the receiver.

[0057] Step 3: Based on the joint mapping and phase-aligned precoding design of the transmitter, the receiver calculates the equivalent channel coefficients and the Euclidean distance parameters of the receiver constellation diagram based on the receiver channel state information, and performs equalization and I / Q path separation processing on the received signal.

[0058] In this step, the receiver of the k-th user first calculates the equivalent channel coefficients based on the reference signal at the receiving end. Euclidean distance parameters of the receiver constellation diagram Then, the received signal is equalized and I / Q separated. For simplicity, the subscript k representing the user index number is omitted, and it is represented as:

[0059]

[0060] in This represents the equalized I-channel and Q-channel signals; These represent the operations of extracting the real part and the imaginary part of a complex number, respectively. Let σ represent the channel noise components of the I-channel signal and the Q-channel signal, with power σ. 2 / 2.

[0061] Step 4: Corresponding to the bit stream allocation result at the transmitting end, the receiving end decodes the bit streams allocated in the shared layer and all bit streams in the private layer. After calculating the log-likelihood ratio of all bit streams, it sends them to the channel decoder to recover the bit data of each user source.

[0062] In this step, each user only needs to decode the bit stream allocated to them in the shared layer and all the bit streams in their own private layer, without decoding the bit streams allocated to other users. That is, no serial interference cancellation is required, and therefore the rate of the shared layer symbol is not limited by the worst-performing user in the channel.

[0063] The calculation process for the log-likelihood ratio of each bitstream is as follows:

[0064] Since the I and Q signal processing flows are the same in constellation diagrams, taking the I-channel signal as an example: the equalized I-channel signal carries multiple bit streams. For each bit stream, the log-likelihood ratio of the κ-th bit stream is... The calculation formula is:

[0065]

[0066] in express Take the set of sub-constellation points corresponding to 0; express Take the set of sub-constellation points corresponding to 1.

[0067] In the actual implementation, a polynomial linear mapping is used to further reduce the computational complexity of each bit.

[0068] It is worth noting that the contents not described in detail in the embodiments of the present invention belong to the prior art known to those skilled in the art.

[0069] This invention also provides an electronic device, including a memory and a processor, wherein the memory stores a computer program and the processor is configured to run the computer program to perform the method.

[0070] This invention also provides a computer storage medium storing a plurality of instructions adapted for loading and executing the method by a processor.

[0071] The implementation of the invention will be further described below with reference to the accompanying drawings and specific examples. This example considers a downlink multiple access transmission scenario with a single base station and two users. The desired constellation diagram size for each user receiver is M = 16 (for simplicity, it is assumed that the desired constellation diagram size is the same for each user receiver), that is, the combined constellation diagram of the shared layer and a single private layer should have 16 points, corresponding to 4 bit streams. Correspondingly, the transmitter can adjust the number of bit streams in the shared layer and each private layer according to the actual user channel conditions (denoted as m0+n0, m1+n1, m2+n2 respectively), satisfying the following conditions.

[0072] The expression m0+n0+m1+n1=m0+n0+m2+n2=4 is sufficient.

[0073] In addition, the transmitter also needs to allocate the bit stream in the shared layer to each user, that is, determine the number of bit streams in the shared layer occupied by each user. In this embodiment, m0 = n0 = 1, m1 = m2 = n1 = n2 = 1, and each of the two users in the shared layer is allocated a bit stream.

[0074] At the transmitting end, the source bit data of each user is channel-coded to obtain coded bits. Based on the parameters mentioned above, the coded bits of each user are split into shared layer bits and private layer bits in a 1:2 ratio. Then, the shared layer bits of the two users are combined together and carried on two bit streams in the shared layer symbol respectively.

[0075] like Figure 2 The diagram shown is a schematic of the transceiver constellation structure in a two-user scenario, as illustrated in this invention. Each user occupies one bitstream in the shared layer, and they are jointly mapped to the shared layer symbol s0. Based on this, the remaining bits of each user are carried in two bitstreams in their respective private layers. Their mapping rules are adjusted according to the bit values ​​in the shared layer, i.e., jointly mapped to two private layer symbols s1 and s2 according to equation (2). It should be emphasized that during the above mapping process, the Euclidean distance parameters corresponding to each constellation diagram need to be optimized and adjusted according to the actual channel conditions.

[0076] Because the Euclidean distances of constellation points in the hierarchical constellation diagram observed by each user are specifically designed, users do not need to perform serial interference cancellation in certain working modes, thus avoiding interference between shared data and private data. In other words, a high user rate can be achieved using only a simple receiving and processing procedure.

[0077] The transmitter then needs to perform phase-aligned orthogonal precoding. Specifically, assuming the two user channels are h1 and h2, the corresponding channel complex correlation coefficients are... ρ * It is the conjugate of ρ; the channel angle is θ = arccos(|ρ|), and the chordal distance between the channel vectors is... To satisfy the orthogonality constraint of equation (4) and the phase alignment constraint of equation (5), the precoding vectors of the shared layer and the two private layers can be set as follows:

[0078]

[0079] θ0 is an adjustable private layer direction parameter that needs to be set according to the actual rate requirements and signal-to-noise ratio of the two users; α0, α1, and α2 are adjustable power allocation coefficients corresponding to the three beams, respectively.

[0080] At the receiving end, each user first separates the received I and Q channels after channel equalization, calculates the log-likelihood ratio of the allocated bit stream according to the user-bit stream allocation result and formula (10), and sends the calculation result to the channel decoder to recover the source bit data of each user.

[0081] Furthermore, those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware, and the corresponding program can be stored in a computer-readable storage medium, such as a read-only memory, a disk, or an optical disk.

[0082] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims. The information disclosed in the background section is intended only to enhance the understanding of the overall background technology of the present invention and should not be construed as an admission or implication in any way that such information constitutes prior art known to those skilled in the art.

Claims

1. A multi-beam parallax hierarchical modulation multiple access method, characterized in that, The method includes: Step 1: The transmitter splits the bit data encoded by each user's channel into a shared part and a private part according to the actual channel conditions of each user, and maps them together on the hierarchical constellation diagram according to a specific bit stream layering and allocation scheme. In step 1, the transmitter processes the source bit data of each user through independent channel coding according to the actual channel conditions of each user to obtain the corresponding encoded bits. Then, the encoded bits of each user are split into two parts: shared layer bits and private layer bits. The shared layer bits of each user are combined together to form the total shared layer bits, while the private layer bits of each user are processed separately. Shared layer and private layer bit data are allocated to different bit streams on a given constellation diagram at the transmitting end, and the number of bit streams allocated to each layer is optimized according to the actual scenario; After splitting the encoded bits for each user, the shared layer bits are first mapped to shared layer symbols using Gray mapping. Bits from different users in the shared layer are carried on different bitstreams, i.e., modulated into shared layer symbols using bitstream demultiplexing. Meanwhile, the transmitter adopts a layered orthogonal amplitude modulation (H-QAM) constellation diagram. During symbol mapping, the transmitter needs to optimize the Euclidean distance parameters corresponding to each bit stream in the constellation diagram based on the user channel conditions. For a given constellation diagram Euclidean distance parameter, the mapping process for shared layer symbols is expressed as follows: （1） in Represents the real part of the symbol; Indicates the imaginary part of the symbol; superscript These represent I and Q branches respectively; These represent the index numbers of the bit streams on the I and Q paths, respectively; This indicates the number of I-path and Q-path bitstreams corresponding to the shared layer; These represent the first and second paths on the I and Q paths of the shared layer, respectively. A bit stream; Then, these represent the first and second paths on the I and Q paths in the shared layer, respectively. The Euclidean distance parameters of each bit stream on the constellation diagram; In shared layer symbols Once determined, the private layer needs to adjust its mapping rules based on the bit values ​​of the shared layer to ensure that the composite constellation diagram of the shared and private layers maintains the Gray mapping structure. For the first... Private layer symbol corresponding to each user The joint mapping process is expressed as: （2） in They represent the first The number of I-path and Q-path bitstreams in the private layer corresponding to each user; They represent the first In the private layer corresponding to each user, the first path on the I-path and the first path on the Q-path... A bit stream; They represent the first In the private layer corresponding to each user, the first path on the I-path and the first path on the Q-path... Euclidean distance parameters corresponding to each bit stream; For ease of subsequent representation, the energy of each transmitted symbol has been normalized, i.e., we have ; Step 2: After obtaining the symbols corresponding to the shared layer and each private layer through joint mapping, the transmitter precodes their phases and then superimposes and transmits them. Step 3: Based on the joint mapping and phase-aligned precoding design of the transmitter, the receiver calculates the equivalent channel coefficients and the Euclidean distance parameters of the receiver constellation diagram based on the receiver channel state information, and performs equalization and I / Q path separation processing on the received signal. Step 4: Corresponding to the bit stream allocation result at the transmitting end, the receiving end decodes the bit streams allocated in the shared layer and all bit streams in the private layer. After calculating the log-likelihood ratio of all bit streams, it sends them to the channel decoder to recover the bit data of each user source.

2. The multi-beam parallax hierarchical modulation multiple access method according to claim 1, characterized in that, In step 2, after obtaining the symbols corresponding to the shared layer and each private layer through joint mapping, the transmitted signal is represented as follows: （3） in Indicates the number of users; Representing the shared layer symbol and the first There are 1 private layer symbol, where the k-th private layer is the private layer corresponding to the k-th user; Representing the shared layer symbol and the first The precoding vector of each private layer symbol; To eliminate interference between private layers, the precoding vectors of each private layer symbol are configured to satisfy orthogonality constraints: （4） in Indicates the first The conjugate transpose of a user channel vector; Furthermore, since the shared layer and each private layer are transmitted on different beams, the precoding vectors must also satisfy phase alignment constraints to ensure that the shared layer symbols received by each user are in phase with the required private layer symbols. （5） in This indicates the phase operation for taking complex numbers; In practical implementation, the precoding vector of the shared layer symbols is first determined. Then, a certain phase rotation is performed on the precoding vector of each private layer symbol to satisfy the constraint condition; The transmitter precodes the shared layer and each private layer symbol and then superimposes them for transmission. The shared layer portion of all users is transmitted in the form of bitstream multiplexing within the same symbol, while the remaining private layer portion of each user is transmitted separately on a private layer symbol. Each user will only receive the shared layer symbol stream and the private layer symbol stream it needs. Received signal for each user Represented as: （6） in Indicates the first The additive white Gaussian noise at the receiver for each user has a power of ; Due to the phase rotation operation at the transmitting end, the received signal in equation (6) can be equivalently expressed as: （7） in ; Definition of the first Normalized synthesized received symbols for individual users Then, formula (7) can be further simplified to: （8） in It is the first Equivalent channel gain for each user; Further analysis of the normalized synthesized received symbols for each user It can be seen as sampling from the I and Q paths respectively. and The H-QAM constellation diagram for each bit stream, and the correspondence between each bit stream and the bit stream at the transmitting end are as follows: （9） in They represent the first The user received the first [number] message on the I and Q lines. The and the first There are 1 bit streams, and the Euclidean distance parameter for each bit stream is: （10） in They represent the first The user received the first [number] message on the I and Q lines. The and the first Euclidean distance parameter corresponding to each bit stream; Combining formulas (7) and (10), we can obtain: （11） Based on the transmitter design, each receiver can only observe its own private layer, while all users can observe the same shared layer. The shared layer and private layer observed by each user constitute a unique hierarchical constellation diagram that satisfies the Gray mapping structure, which constitutes the constellation diagram parallax phenomenon. Under this hierarchical constellation diagram, each user only needs to complete data reception with the complexity of a single-user receiver, without the need to use serial interference cancellation to eliminate interference between multiple beams, thereby reducing the complexity of the receiver.

3. The multi-beam parallax hierarchical modulation multiple access method according to claim 2, characterized in that, In step 3, the first The receiver of each user first calculates the equivalent channel coefficient based on the reference signal at the receiving end. Euclidean distance parameters of the receiver constellation diagram Then, the received signal is equalized again and I / Q path separated. For simplicity, the subscript representing the user index number is omitted. , is represented as: （12） in This represents the equalized I-channel and Q-channel signals; These represent the operations of extracting the real part and the imaginary part of a complex number, respectively. Let I represent the channel noise component of the I-channel signal and the channel noise component of the Q-channel signal, with power . .

4. The multi-beam parallax hierarchical modulation multiple access method according to claim 1, characterized in that, In step 4, the log-likelihood ratio of each bitstream is calculated as follows: Since the I and Q signal processing flows in a constellation diagram are the same, taking the I signal as an example: the equalized I signal carries multiple bit streams. For each bit stream, the first... The log-likelihood ratio of each bit stream The calculation formula is: （13） in express Take the set of sub-constellation points corresponding to 0; express Take the set of sub-constellation points corresponding to 1.

5. An electronic device, comprising a memory and a processor, characterized in that, The memory stores a computer program, and the processor is configured to run the computer program to perform the method according to any one of claims 1 to 4.

6. A computer storage medium, characterized in that, The computer storage medium stores a plurality of instructions adapted for loading by a processor and executing the method of any one of claims 1 to 4.

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