Multi-beam parallax layered modulation multiple access method

Abstract

The invention discloses a multi-beam parallax hierarchical modulation multiple access method, which comprises the following steps that: a transmitting end splits bit data after channel coding of each user into a shared part and a private part according to the actual channel condition of each user; the transmitting end performs phase rotation pre-coding on the constellation points and then transmits the constellation points in an overlapped manner, so that the constellation points at the receiving end are aligned in phase The receiving end calculates an equivalent channel coefficient and a receiving end constellation diagram Euclidean distance parameter based on the receiving end channel state information, and performs primary equalization and I / Q path separation processing on a received signal; and a receiving end decodes the bit streams distributed in the shared layer and all the bit streams in the private layer, and after the log-likelihood ratios of all the bit streams are calculated, the log-likelihood ratios are sent to a channel decoder to be recovered to obtain the bit data of each user source. According to the method, a user does not need to perform serial interference cancellation in some working modes, interference of shared part data to private part data can be avoided, and a relatively high user rate is realized.

Description

Technical Field

[0001] The present invention relates to a wireless communication system, and in particular to a multi-beam parallax hierarchical modulation multiple access method. Background Art

[0002] Limited by the limited spectrum resources, base stations in wireless communication systems usually need to divide the wireless spectrum into time-frequency resource blocks and allocate them to multiple users to serve them simultaneously. Downlink multiple access technology is the key technology to address this issue. Existing downlink multiple access technologies can be mainly divided into two types: orthogonal multiple access technology and non-orthogonal multiple access technology. Among them, orthogonal multiple access technology avoids interference between users by orthogonally dividing non-overlapping time-frequency resource blocks to each user, thus making the complexity of the user receiver relatively low. However, the orthogonal resource allocation method also results in a relatively low spectral efficiency of the system, making it difficult to meet the growing service demands. In contrast, non-orthogonal multiple access technology allows multiple users to overlap on the same time-frequency resource block and uses more complex signal processing technologies to address the impact of interference between users on the user rate, thereby achieving a further improvement in the spectral efficiency of the system. For example, several key implementation methods of downlink multi-user overlapping transmission (hereinafter referred to as MUST technology) have been specified in the 3GPP TR36.859 protocol. In this method, several users with different channel gains form a transmission group. The users within the group use their respective constellation mappings and are configured with different powers and then superimposed; or bit mapping is performed on a unified constellation diagram. Serial interference cancellation technology is an essential receiving technology in this method, that is, users with better channel conditions within a group need to first decode the information of users with worse channel conditions, reconstruct their signals, and then cancel them in the received signal before receiving their own signals. This method increases the receiving complexity under non-orthogonal receiving conditions, thus affecting the further deployment and promotion of this technology in practical systems.

[0003] With the increase in the number of base station antennas, space division multiple access technology brings obvious spectral efficiency gains by differentiating each user data stream in the spatial domain. At the same time, since user data is separated in space, the receiver can maintain a relatively low complexity. However, when the user distribution is relatively dense and the channel spatial correlation is strong, this method will show obvious performance degradation. In recent years, a new type of multiple access technology called rate split multiple access has been proposed. It realizes the integration of existing mainstream multiple access technologies based on the rate split idea and shows performance advantages in many aspects such as spectral efficiency, energy efficiency, and channel state information robustness. However, it also needs to perform partial decoding interference of serial interference cancellation technology at the receiving end to obtain relatively ideal performance, so there is also a problem of relatively high receiver complexity. Summary of the Invention

[0004] The object of the present invention is to provide a multi-beam parallax hierarchical modulation multiple access method, which enables users to avoid interference from shared data to private data without serial interference cancellation in certain working modes, and can achieve a high user rate with a simple receiving processing flow.

[0005] The object of the present invention is achieved by the following technical solutions:

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

[0007] Step 1, the transmitting end splits the bit data after channel coding of each user into a shared part and a private part according to the actual channel conditions of each user, and jointly maps them on a hierarchical constellation diagram according to a specific bit stream hierarchical and allocation scheme;

[0008] Step 2, after obtaining the symbols corresponding to the shared layer and each private layer through joint mapping, the transmitting end performs pre-coding of the phase and then superimposes and transmits them;

[0009] Step 3, based on the joint mapping and phase alignment pre-coding design at the transmitting end, the receiving end calculates the equivalent channel coefficient and the Euclidean distance parameter of the receiving end constellation diagram based on the receiving end channel state information, and performs a first 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 stream allocated in the shared layer and all the bit streams in the private layer, and after calculating the log-likelihood ratio of all the bit streams, sends them into a channel decoder to recover the source bit data of each user.

[0011] It can be seen from the above technical solutions provided by the present invention that the above method enables users to avoid interference from shared data to private data without serial interference cancellation in certain working modes, and can achieve a high user rate with a simple receiving processing flow, having good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention, and those of ordinary skill in the art can obtain other drawings without creative efforts based on these drawings.

[0013] Figure 1 It is a schematic flowchart of the multi-beam parallax hierarchical modulation multiple access method provided by the embodiment of the present invention;

[0014] Figure 2This is a schematic diagram of the transceiver constellation diagram structure in a two-user scenario for the example of the present invention. Detailed implementation manners

[0015] The following clearly and completely describes the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments, which does not constitute a limitation to the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0016] As Figure 1 shown is a schematic diagram of the process of the multi-beam parallax hierarchical modulation multiple access method provided by the embodiment of the present invention. The method includes:

[0017] Step 1: The transmitting end splits the bit data after channel coding of each user into a shared part and a private part according to the actual channel conditions of each user, and jointly maps them on a hierarchical constellation diagram according to a specific bit stream hierarchical and allocation scheme;

[0018] In this step, the transmitting end performs independent channel coding processing on the source bit data of each user according to the actual channel conditions of each user to obtain the corresponding coded bits, and then splits the coded bits of each user into two parts: shared layer bits and private layer bits. Among them, the shared layer bits of each user are combined together to form the total shared layer bits, and the private layer bits of each user are processed separately;

[0019] Taking a two-user system as an example, the coded bits of the two users after splitting constitute a shared layer and two parallel private layers. The shared layer is composed of partial bits of the two users, and each private layer only contains the bit data of a certain user;

[0020] The bit data of the shared layer and the private layer will be 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 Gray mapped to shared layer symbols. Different users' bits in the shared layer are carried on different bit streams, that is, modulated into the shared layer symbol s0 in the form of bit stream division multiplexing. At the same time, the transmitter uses a hierarchical quadrature amplitude modulation (H-QAM) constellation diagram. Compared with the general uniform QAM constellation diagram, the main difference is that the Euclidean distance parameters of each bit stream on the constellation diagram are adjustable. Therefore, when mapping symbols at the transmitter, it is necessary to optimize the Euclidean distance parameters corresponding to each bit stream of the constellation diagram according to the user channel conditions. For a given constellation diagram Euclidean distance parameter, the mapping process of the shared layer symbols is expressed as:

[0022]

[0023] where represents the real part of the symbol; represents the imaginary part of the symbol; the superscripts i and q represent the I and Q branches respectively; κ and l represent the index numbers of the bit streams on the I and Q branches respectively; m0 and n0 represent the number of bit streams on the I and Q branches corresponding to the shared layer; respectively represent the j-th bit stream on the I and Q branches in the shared layer; then respectively represent the Euclidean distance parameters corresponding to the j-th bit stream on the I and Q branches in the shared layer on the constellation diagram;

[0024] After the shared layer symbol s0 is determined, the private layer needs to adjust its mapping rule according to the value of the shared layer bits to ensure that the combined constellation diagram of the shared layer and the private layer maintains the Gray mapping structure. For the private layer symbol s k corresponding to the k-th user, its joint mapping process is expressed as:

[0025]

[0026] where m k , n k respectively represent the number of bit streams on the I and Q branches in the private layer corresponding to the k-th user; respectively represent the j-th bit stream on the I and Q branches in the private layer corresponding to the k-th user; respectively represent the Euclidean distance parameters corresponding to the j-th bit stream on the I and Q branches in the private layer corresponding to the k-th user;

[0027] For the convenience of subsequent representation, the energies of each transmitted symbol are normalized, that is, there is

[0028] Step 2: After obtaining the symbols corresponding to the shared layer and each private layer through joint mapping, the transmitter performs pre-coding of the phase on them and then superimposes and transmits;

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

[0030] In this step, after jointly mapping to obtain the symbols corresponding to the shared layer and each private layer, the transmitted signal is expressed as:

[0031]

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

[0033] To eliminate the interference between private layers, the precoding vectors of the symbols of each private layer are set to satisfy the orthogonality constraint condition:

[0034]

[0035] where represents the conjugate transpose of the channel vector of the k-th user; in specific implementation, other compromise methods can also be adopted, such as the minimum mean square error (MMSE) method, etc., to retain a certain degree of interference between the symbols of the private layers, but it does not prevent the receiver from using a simple receiving method to complete the reception, and the remaining interference of the private stream is regarded as noise for processing.

[0036] In addition, since the shared layer and each private layer are transmitted on different beams, in order to ensure that the phases of the symbols of the shared layer received by each user have no deviation from the required symbols of the private layer, the precoding vector also needs to satisfy the phase alignment constraint condition:

[0037]

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

[0039] In specific implementation, the precoding vector p0 of the symbol of the shared layer can be determined first, and then a certain phase rotation is performed on the precoding vectors of the symbols of each private layer to satisfy this constraint condition;

[0040] After precoding and superimposing the symbols of the shared layer and each private layer at the transmitter, the shared layer part of all users is carried in the same symbol in the form of bit stream multiplexing and transmitted, and the remaining private layer parts of each user are carried on a private layer symbol separately and transmitted; each user will only receive the shared symbol stream of the shared layer and the symbol stream of the private layer it needs, and the received signal y of the k-th userk Expressed as:

[0041]

[0042] where n k represents the additive white Gaussian noise of the k-th user at the receiving end, and its power is σ 2 ;

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

[0044]

[0045] where

[0046] Further define the normalized composite received symbol of the k-th user Then formula (7) is further simplified to:

[0047]

[0048] where is the equivalent channel gain of the k-th user;

[0049] Further analyze the normalized composite received symbol of each user It can be regarded as sampled from the H-QAM constellation diagram with m0 + m and n0 + n bit streams on the I-channel and Q-channel respectively k and n0 + n k The corresponding relationship between each bit stream and the bit stream at the transmitting end is:

[0050]

[0051] where respectively represent the κ-th and l-th bit streams received by the k-th user on the I-channel and Q-channel, and the Euclidean distance parameters corresponding to each bit stream are:

[0052]

[0053] where respectively represent the Euclidean distance parameters corresponding to the κ-th and l-th bit streams received by the k-th user on the I-channel and Q-channel;

[0054] Combining formulas (7)-(10) gives:

[0055]

[0056] From the above analysis, it can be seen that benefiting from 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 the private layer observed by each user exactly form a unique hierarchical constellation diagram that satisfies the Gray mapping structure, that is, the constellation diagram parallax phenomenon unique to the present invention is formed. Under this layered constellation diagram, each user only needs to complete data reception with the complexity of a single-user receiver, without using 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 alignment precoding design at the transmitter, the receiver calculates the equivalent channel coefficient and the Euclidean distance parameter of the receiver constellation diagram based on the receiver channel state information, and performs a first 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 coefficient and the Euclidean distance parameter of the receiver constellation diagram based on the reference signal at the receiver, and then performs a first equalization on the received signal and separates the I / Q paths. For simplicity of expression, the subscript k representing the user index number is omitted and expressed as:

[0059]

[0060] where represents the I-channel signal and the Q-channel signal after equalization; respectively represent the operations of taking the real part and the imaginary part of the complex number; represents the channel noise component of the I-channel signal and the channel noise component of the Q-channel signal, and the power is σ 2 / 2.

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

[0062] In this step, each user only needs to decode the bit stream allocated in the shared layer and all the bit streams in its own required private layer, and does not decode the bit streams allocated to other users, that is, there is no need to perform serial interference cancellation. Therefore, for the shared layer symbols, its rate is not limited by the user with the worst channel.

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

[0064] Since the processing flows of the I and Q branch signals of the constellation diagram are the same, taking the I branch signal as an example: The signal after I branch equalization carries multiple bitstreams. For each of these bitstreams, the log-likelihood ratio of the κ-th bitstream The calculation formula is:

[0065]

[0066] Where represents the set of sub-constellation points corresponding to taking 0; represents the set of sub-constellation points corresponding to taking 1.

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

[0068] It should be noted that the content not described in detail in the embodiments of the present invention belongs to the prior art well-known to those skilled in the art.

[0069] The embodiments of the present invention also provide an electronic device, including a memory and a processor. A computer program is stored in the memory, and the processor is configured to run the computer program to execute the method.

[0070] The embodiments of the present invention also provide a computer storage medium. The computer storage medium stores multiple instructions, and the instructions are adapted to be loaded and executed by the processor to execute the method.

[0071] The following further illustrates the implementation manners of the invention with reference to the accompanying drawings and specific examples. This example considers a downlink multi-access transmission scenario of a single base station with 2 users. The desired constellation size M = 16 for each user's receiver (for simplicity of description, it is assumed that the desired constellation sizes of each user's receiver are the same), that is, the number of points of the combined constellation of the shared layer and a single private layer should be 16, corresponding to 4 bitstreams. Correspondingly, the transmitter can adjust the number of bitstreams 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

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

[0073] In addition, the transmitter also needs to complete the allocation of the bitstreams in the shared layer to each user, that is, determine the number of bitstreams in the shared layer occupied by each user. In this embodiment, m0 = n0 = 1, m1 = m2 = n1 = n2 = 1 are selected, and one bitstream is respectively allocated to the two users in the shared layer.

[0074] At the transmitting end, the source bit data of each user is channel-encoded to obtain the encoded bits. According to the above parameter selection, the encoded bits of each user are split into shared-layer bits and private-layer bits in a ratio of 1:2. Subsequently, the shared-layer bits of the two users are combined together and carried on two bitstreams in the shared layer symbols respectively.

[0075] As Figure 2 shown in the schematic diagram of the transceiver constellation diagram structure of the example of the present invention in a two-user scenario, where each of the two users occupies one bitstream in the shared layer and is jointly Gray-mapped to the shared layer symbol s0. On this basis, the remaining bits of the two users are carried on two bitstreams in their respective private layers, and their mapping rules are adjusted according to the bit values in the shared layer, that is, jointly mapped to two private layer symbols s1, s2 according to Equation (2). It should be emphasized that in 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] Since the Euclidean distances of the constellation points in the hierarchical constellation diagram observed by each user are specifically designed, it is possible for the user to avoid the interference of the shared part of the data on the private part of the data without performing serial interference cancellation in some working modes, that is, a relatively high user rate can be achieved only by using a simple receiving processing flow.

[0077] After that, the transmitting end also needs to perform phase-aligned orthogonal precoding. Specifically, assuming that the channels of the two users are h1 and h2, and the corresponding channel complex correlation coefficient is ρ * is the conjugate of ρ; the channel included angle is θ = arccos(|ρ|), and the chord distance between the channel vectors is To satisfy the orthogonal 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 respectively as:

[0078]

[0079] where θ0 is an adjustable private layer direction parameter and 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 distribution coefficients corresponding to the three beams respectively.

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

[0081] In addition, those of ordinary skill in the art can understand that all or part of the steps in implementing the methods of the above embodiments can be completed by instructing relevant hardware through a program, and the corresponding program can be stored in a computer-readable storage medium. The above-mentioned storage medium can be a read-only memory, a magnetic disk, an optical disk, or the like.

[0082] As described above, the above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims. The information disclosed in the background art part of this article is only intended to deepen the understanding of the overall background art of the present invention, and should not be regarded as an admission or any form of implication that this information constitutes the prior art already known to those skilled in the art.

Claims

1. A multi-beam parallax layered modulation multiple access method, characterized in that: The method comprises: Step 1: The transmitter splits the bit data of each user after channel coding into a shared part and a private part according to the actual channel conditions of each user, and maps them jointly on a layered constellation diagram according to a specific bit stream layering and allocation scheme; Step 2: After the symbols corresponding to the shared layer and each private layer are obtained through joint mapping, the transmitting end performs phase precoding on them and then superimposes and sends them; Step 3: Based on the joint mapping and phase alignment precoding design of the transmitting end, the receiving end calculates the equivalent channel coefficient and the Euclidean distance parameter of the receiving end constellation diagram based on the receiving end channel state information, and performs primary equalization and I / Q path separation processing on the received signal; Step 4: Corresponding to the bit stream allocation result of the transmitter, the receiver decodes the bit stream allocated in the shared layer and all the bit streams in the private layer. After calculating the log-likelihood ratio of all the bit streams, it sends them to the channel decoder to recover the source bit data of each user.

2. The multi-beam parallax layered modulation multiple access method according to claim 1, characterized in that: 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 coded bits, and then splits the coded bits of each user into two parts: shared layer bits and private layer bits. The shared layer bits of each user are combined to form the total shared layer bits, and the private layer bits of each user are processed separately. The shared layer and private layer bit data will be allocated to different bit streams on a given constellation diagram at the transmitter, where the number of bit streams allocated to each layer is optimized based on the actual scenario.

3. The multi-beam parallax layered modulation multiple access method according to claim 2, characterized in that: In step 1, after splitting the coded bits of each user, the shared layer bits are first mapped to shared layer symbols through Gray mapping, where the bits of different users in the shared layer are carried on different bit streams, that is, modulated into shared layer symbols s0 in the form of bit stream multiplexing; at the same time, the transmitter adopts a layered quadrature amplitude modulation H-QAM constellation diagram. When mapping symbols, the transmitter needs to optimize the Euclidean distance parameters corresponding to each bit stream of the constellation diagram according to the user channel conditions. For a given constellation diagram Euclidean distance parameter, the mapping process of the shared layer symbol is expressed as: in represents the real part of the sign; represents the imaginary part of the sign; The superscripts i and q represent I and Q branches 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; denote the j-th bit stream on the I path and Q path in the shared layer respectively; Then they represent the Euclidean distance parameters corresponding to the j-th bit stream on the I path and Q path in the shared layer on the constellation diagram respectively; After the shared layer symbol s0 is determined, the private layer needs to adjust its mapping rule according to the shared layer bit value to ensure that the composite constellation of the shared layer and the private layer maintains the Gray mapping structure. For the private layer symbol s corresponding to the kth user k , and its joint mapping process is expressed as: Where m k ,n k They represent the number of bit streams of I and Q in the private layer corresponding to the kth user respectively; They represent the j-th bit stream on the I and Q paths in the private layer corresponding to the k-th user respectively; They respectively represent the Euclidean distance parameters corresponding to the j-th bit stream on the I path and the Q path in the private layer corresponding to the k-th user; To facilitate subsequent representation, the energy of each transmitted symbol is normalized, that is, 4. The multi-beam parallax layered modulation multiple access method according to claim 3, characterized in that: In step 2, after the symbols corresponding to the shared layer and each private layer are obtained through joint mapping, the transmitted signal is expressed as: Where K represents the number of users; s0,s k represent the shared layer symbol and the kth private layer symbol respectively, where the kth private layer is the private layer corresponding to the kth user; p0, p k denote the precoding vectors of the shared layer symbol and the kth private layer symbol respectively; To eliminate interference between private layers, the precoding vectors of the symbols in each private layer are set to meet the orthogonality constraint: in represents the conjugate transpose of the kth user channel vector; In addition, since the shared layer and each private layer are transmitted on different beams, in order to ensure that the phase of the shared layer symbols received by each user does not deviate from the required private layer symbols, the precoding vector also needs to meet the phase alignment constraint: Where ∠(·) represents the phase operation of taking a complex number; In the specific implementation, the precoding vector p0 of the shared layer symbol is first determined, and then a certain phase rotation is performed on the precoding vector of each private layer symbol to meet the constraint condition; The transmitter precodes the shared layer and each private layer symbol and sends them in a superimposed manner. The shared layer part of all users is sent in the same symbol in the form of bit stream multiplexing, and the remaining private layer part of each user is sent separately on a private layer symbol. Each user will only receive the shared shared layer symbol stream and the private layer symbol stream required by itself. The received signal y of the kth user k It is expressed as: where n k represents the additive Gaussian white noise of the kth user at the receiving end, and its power is σ 2 ; Due to the phase rotation operation at the transmitting end, the received signal in formula (6) can be equivalently expressed as: in Define the normalized composite received symbol of the kth user Then formula (7) is further simplified as: in is the equivalent channel gain of the kth user; Further analysis of the normalized composite received symbols of each user It can be seen as sampling from m0+m on the I and Q paths respectively. k and n0+n k The H-QAM constellation diagram of the bit streams, the corresponding relationship between each bit stream and the bit stream of the transmitter is: in They represent the k-th and l-th bit streams received by the k-th user on the I and Q paths, respectively. The Euclidean distance parameters corresponding to each bit stream are: in denote the Euclidean distance parameters corresponding to the κth and lth bit streams received by the kth user on the I and Q paths, respectively; Combining formulas (7)-(10) yields: Based on the design of the transmitter, 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 layered constellation diagram, each user only needs the complexity of a single-user receiver to complete data reception, without the need to use serial interference cancellation to eliminate interference between multiple beams, thereby reducing the complexity of the receiving end.

5. The multi-beam parallax layered modulation multiple access method according to claim 4, characterized in that: In step 3, the receiver of the kth user first calculates the equivalent channel coefficient based on the reference signal of the receiving end. Euclidean distance parameter from the receiving end constellation diagram After that, the received signal is equalized once and the I / Q path is separated. To simplify the expression, the subscript k representing the user index number is omitted, and it is expressed as: in Indicates the I-channel signal and Q-channel signal after equalization; Respectively represent the operation of taking the real part and imaginary part of a complex number; It represents the channel noise component of the I-path signal and the channel noise component of the Q-path signal, and the power is σ 2 / 2.

6. The multi-beam parallax layered modulation multiple access method according to claim 1, characterized in that: In step 4, the log-likelihood ratio calculation process of each bit stream is: Since the I and Q branch signal processing procedures of the constellation diagram are the same, take the I signal as an example: the I-path equalized signal carries multiple bit streams. For each of the bit streams, the log-likelihood ratio of the κth bit stream is The calculation formula is: in express Take the sub-constellation point set corresponding to time 0; express The sub-constellation point set corresponding to 1.

7. An electronic device comprising a memory and a processor, characterized in that: A computer program is stored in the memory, and the processor is configured to run the computer program to perform the method according to any one of claims 1 to 6.

8. A computer storage medium, characterized in that The computer storage medium stores a plurality of instructions, and the instructions are suitable for being loaded by a processor and executing the method according to any one of claims 1 to 6.

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