Signal transmission method, device, access node, processing unit, system and medium

Abstract

The present application provides a signal transmission method, device, access node, processing unit, system and medium. The method determines the multi-user uplink data signal and the first inter-user interference information matrix corresponding to the current AP according to the channel estimation of the current AP; transmits the multi-user uplink data signal and the first inter-user interference information matrix to the next level node of the current AP in the forward backhaul link.

Description

Technical Field

[0001] The present application relates to a wireless communication network, for example, to a signal transmission method, device, access node, processing unit, system and medium. Background Art

[0002] Radio Stripe is an efficient and low-cost way to implement Cell-Free. Multi-level wireless access points (APs) are connected to the central processing unit (CPU) through front-haul links. For the uplink data signals sent by the terminal and the downlink data signals sent by the CPU, the traditional method performs maximum ratio combining or sequential processing in each AP, which can reduce the load on the front-haul to a certain extent. However, the signal-to-noise ratio of the signal finally recovered on the CPU is relatively low, which affects the signal transmission rate. Summary of the invention

[0003] The present application provides a signal transmission method, device, access node, processing unit, system and medium, which improve the signal-to-noise ratio of a received signal by transmitting a multi-user uplink data signal and a first inter-user interference information matrix.

[0004] The present application provides a signal transmission method, including:

[0005] Determine, according to the channel estimation of the current AP, a multi-user uplink data signal corresponding to the current AP and a first inter-user interference information matrix;

[0006] The multi-user uplink data signal and the first inter-user interference information matrix are transmitted to a next-level node of the current AP in a forward backhaul link.

[0007] The present application also provides a signal transmission method, including:

[0008] Receiving a multi-user uplink data signal and a first inter-user interference information matrix transmitted by the last AP in the forward return link;

[0009] A signal for demodulation is determined according to the multi-user uplink data signal and the first inter-user interference information matrix.

[0010] The present application also provides a signal transmission method, including:

[0011] Obtaining information related to a multi-user downlink data signal and a second user inter-interference information matrix;

[0012] The transmission signal of the current AP is determined according to the related information of the multi-user downlink data signal and the second inter-user interference information matrix and the channel estimation of the current AP.

[0013] The present application also provides a signal transmission method, including:

[0014] A multi-user downlink data signal is sent to each AP in the forward backhaul link, or a product signal of the multi-user downlink data signal and the second inter-user interference information matrix is ​​sent.

[0015] The embodiment of the present application also provides a signal transmission device, including:

[0016] A multi-user signal determination module, configured to determine a multi-user uplink data signal corresponding to the current AP and a first inter-user interference information matrix according to a channel estimation of the current AP;

[0017] The first cascade transmission module is configured to transmit the multi-user uplink data signal and the first inter-user interference information matrix to a next-level node of the current AP in a forward backhaul link.

[0018] The embodiment of the present application also provides a signal transmission device, including:

[0019] A receiving module, configured to receive a multi-user uplink data signal and a first inter-user interference information matrix transmitted by a last-stage AP in a forward return link;

[0020] The demodulation signal determination module is configured to determine a signal for demodulation according to the multi-user uplink data signal and the first inter-user interference information matrix.

[0021] The embodiment of the present application also provides a signal transmission device, including:

[0022] An acquisition module, configured to acquire information related to a multi-user downlink data signal and an interference information matrix between second users;

[0023] The transmitting module is configured to determine the transmitting signal of the current AP according to the relevant information of the multi-user downlink data signal and the second inter-user interference information matrix and the channel estimation of the current AP.

[0024] The embodiment of the present application also provides a signal transmission device, including:

[0025] The second cascade transmission module is configured to send a multi-user downlink data signal to each AP in the forward backhaul link, or send a product signal of the multi-user downlink data signal and the second inter-user interference information matrix.

[0026] The embodiment of the present application further provides an access node, including:

[0027] one or more processors;

[0028] A storage device for storing one or more programs;

[0029] When the one or more programs are executed by the one or more processors, the one or more processors implement the above-mentioned signal transmission method applied to the access node.

[0030] The present application also provides a CPU, including:

[0031] one or more processors;

[0032] A storage device for storing one or more programs;

[0033] When the one or more programs are executed by the one or more processors, the one or more processors implement the above-mentioned signal transmission method applied to the CPU.

[0034] The embodiment of the present application also provides a signal transmission system, comprising: the above-mentioned CPU, at least one level of the above-mentioned access node, and at least two terminals;

[0035] The CPU transmits signals to each terminal via at least one level of AP.

[0036] An embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, the above-mentioned signal transmission method is implemented. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A flowchart of a signal transmission method provided by an embodiment;

[0038] Figure 2 A schematic diagram of a connection between an access node and a CPU provided by an embodiment;

[0039] Figure 3 A flowchart of another signal transmission method provided by an embodiment;

[0040] Figure 4 A flowchart of another signal transmission method provided by an embodiment;

[0041] Figure 5 A flowchart of another signal transmission method provided by an embodiment;

[0042] Figure 6 A schematic diagram of the structure of a signal transmission device provided by an embodiment;

[0043] Figure 7A schematic diagram of the structure of another signal transmission device provided by an embodiment;

[0044] Figure 8 A schematic diagram of the structure of another signal transmission device provided by an embodiment;

[0045] Fig. 9 A schematic diagram of the structure of another signal transmission device provided by an embodiment;

[0046] Fig.10 A schematic diagram of the hardware structure of an access node provided by an embodiment;

[0047] Fig.11 A schematic diagram of the hardware structure of a central processing unit provided by an embodiment;

[0048] Fig.12 A schematic diagram of a signal transmission system provided by an embodiment. DETAILED DESCRIPTION

[0049] The present application is described below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present application, rather than to limit the present application. It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other arbitrarily. It should also be noted that, for ease of description, only the parts related to the present application rather than all structures are shown in the accompanying drawings.

[0050] In an embodiment of the present application, a signal transmission method is provided, which is applied to each level of AP in a forward return link. When multiple terminals send uplink data signals to a CPU through at least one level of AP, each level of AP processes the received data signal of each terminal to reduce the load of the forward return link and ensure signal transmission efficiency. The data signal sent by each terminal is also collectively referred to as a multi-user uplink data signal. In addition, by transmitting the multi-user uplink data signal and the first inter-user interference information matrix, more information is provided for the CPU's signal processing, thereby improving the signal-to-noise ratio of the CPU received signal.

[0051] Figure 1 A flowchart of a signal transmission method provided by an embodiment is shown in FIG. Figure 1 As shown, the method provided in this embodiment includes step 110 and step 120.

[0052] In step 110, a multi-user uplink data signal and a first inter-user interference information matrix corresponding to the current AP are determined according to the channel estimation of the current AP.

[0053] In the signal transmission system, the CPU provides centralized processing for at least one level of AP, and the terminal mainly refers to the user terminal (User Equipment, UE). Signals are transmitted between multiple UEs and the CPU through at least one level of AP. Figure 2 FIG. 1 is a schematic diagram of a connection between an access node and a CPU provided by an embodiment. Figure 2 As shown, the connection between multiple APs and CPUs constitutes a forward return link, and each AP is a level in the forward return link.

[0054] In this embodiment, for the first-level AP (i.e., the current AP) in the forward return link, the multi-user uplink data signal includes uplink data signals sent by multiple terminals to the CPU through the current AP, and each uplink data signal contains uplink data transmitted by the corresponding terminal. In addition, if there is an upper-level AP of the current AP in the forward return link, the multi-user uplink data signal also includes a multi-user uplink data signal corresponding to the upper-level AP transmitted by the upper-level AP to the current AP, that is, the multi-user uplink data signal of the current AP is the result of combining the multi-user uplink data signal determined according to channel estimation with the multi-user uplink data signal corresponding to the upper-level AP. The multi-user uplink data signal is not only received by each level of AP, but also transmitted to the CPU in sequence through each level of AP.

[0055] For the current AP, the first inter-user interference information matrix is ​​used to represent the interference between the uplink data signal sent by each terminal and the uplink data signal sent by each other terminal. In addition, if there is an upper-level AP of the current AP in the forward return link, the first inter-user interference information matrix is ​​also affected by the first inter-user interference information matrix corresponding to the upper-level AP transmitted by the upper-level AP to the current AP, that is, the first inter-user interference information matrix of the current AP is the result of combining the first inter-user interference information matrix determined according to channel estimation with the first inter-user interference information matrix corresponding to the upper-level AP. The first inter-user interference information matrix is ​​not only determined by each level of AP according to channel estimation, but also transmitted to the CPU in sequence by each level of AP.

[0056] In step 120, the multi-user uplink data signal and the first inter-user interference information matrix are transmitted to a next-level node of the current AP in a forward backhaul link.

[0057] In this embodiment, after receiving uplink data signals from multiple terminals, each AP first estimates its own channel based on the received pilot signal, and the obtained channel estimate is recorded as (i=1,2,...,l,...L, L is the total number or total number of APs), based on its own channel estimation and combined with the received data signal, determine the multi-user uplink data signal and the first inter-user interference information matrix that need to be transmitted to the next level node. If the current AP is the last level AP in the forward return link, that is, the AP directly connected to the CPU, then the next level node of the current AP refers to the CPU; if the current AP is not the last level AP in the forward return link, then the next level node of the current AP refers to the next level AP.

[0058] In this embodiment, each AP level in the forward return link, on the basis of processing the received data signal to reduce the load of the forward return link, transmits a multi-user uplink data signal and a first inter-user interference information matrix, and the CPU performs further signal processing to restore a more accurate signal.

[0059] In one embodiment, each level of AP in the forward return link is provided with at least one antenna; the number of row vectors of the first inter-user interference information matrix is ​​equal to the number of column vectors and is equal to the number of users; the number of row vectors of the multi-user uplink data signal is equal to the number of users, and the number of column vectors is equal to the number of data symbols of the signal received on a single antenna of the current AP.

[0060] In this embodiment, the first inter-user interference information matrix is ​​a matrix of dimension K×K, where K is the number of users, that is, the number of terminals. The multi-user uplink data signal is a matrix of dimension K×D, where K is the number of users, that is, the number of terminals, and D is the number of data symbols contained in the received signal on a single antenna of the current AP, that is, the number of data symbols contained in the data signal transmitted by a single user.

[0061] In one embodiment, the step 101 is further included:

[0062] The channel estimate is determined based on the pilot part of the received signal; or, the channel estimate is determined based on the pilot part of the received signal and the correlation matrix prior information of the multi-user channel; or, the channel estimate is determined based on the pilot part of the received signal and the energy prior information of the multi-user channel.

[0063] In this embodiment, each level of AP can perform channel estimation based on the pilot part of the received signal. If there is prior information (including at least one of the channel correlation matrix prior information and energy prior information), channel estimation is performed based on the pilot part of the received signal and the prior information.

[0064] In one embodiment, step 110 includes:

[0065] When the current AP is a first-level AP, a multi-user uplink data signal corresponding to the current AP is obtained according to the conjugate matrix of the channel estimation of the current AP; when the current AP is not a first-level AP, a current multi-user uplink data signal is obtained according to the conjugate matrix of the channel estimation of the current AP, and is superimposed with the multi-user uplink data signal output by the upper-level AP of the current AP to obtain the multi-user uplink data signal corresponding to the current AP.

[0066] In this embodiment, if the current AP is a first-level AP in the forward return link, the corresponding multi-user uplink data signal can be determined based on the conjugate matrix of its own channel estimation; if the current AP is not a first-level AP, it is necessary to determine the current multi-user uplink data signal based on the conjugate matrix of its own channel estimation and superimpose it with the multi-user uplink data signal transmitted by the previous-level AP.

[0067] In one embodiment, step 110 includes:

[0068] When the current AP is a first-level AP, a first inter-user interference information matrix corresponding to the current AP is obtained based on the channel estimation of the current AP; when the current AP is not a first-level AP, a current first inter-user interference information matrix is ​​obtained based on the channel estimation of the current AP, and is superimposed with the first inter-user interference information matrix output by the upper-level AP of the current AP to obtain the first inter-user interference information matrix corresponding to the current AP.

[0069] In this embodiment, if the current AP is a first-level AP in the forward return link, the corresponding first inter-user interference information matrix can be determined based on the conjugate matrix of its own channel estimation; if the current AP is not a first-level AP, it is necessary to determine the current first inter-user interference information matrix based on the conjugate matrix of its own channel estimation, and superimpose it with the first inter-user interference information matrix transmitted by the previous level AP.

[0070] In one embodiment, the first inter-user interference information matrix includes one of the following: a correlation matrix of a multi-user channel; a sum of a correlation matrix of a multi-user channel and a noise diagonal matrix; an inverse matrix of the sum of a correlation matrix of a multi-user channel and a noise diagonal matrix.

[0071] During the signal transmission process, if each level of AP transmits the received data signal to the CPU, it will cause a large forward return overhead. In this embodiment, each level of AP transmits the multi-user uplink data signal and the first inter-user interference information matrix, that is, transmits the recovered signal to the CPU, which can reduce the load and overhead of the forward return link, and by superimposing the multi-user uplink data signal and the first inter-user interference information matrix of each level of AP with the multi-user uplink data signal and the first inter-user interference information matrix of the upper level AP respectively, and then transmitting them to the next level node, the signal-to-noise ratio of the CPU received signal can be improved.

[0072] The following example illustrates the signal transmission process. In the following example, the number of users is recorded as K, and the multi-user uplink data signal corresponding to the current AP is recorded as X. l , the first inter-user interference information matrix corresponding to the current AP is recorded as R l , l represents the level of the current AP, l≥1 and l≤L; L is the total number or total level of APs, and the received signal of the current AP is recorded as Y l , σ 2 represents the noise of the received signal, I K represents the K×K identity matrix, X est Indicates the signal for demodulation finally determined by the CPU.

[0073] When the current AP contains multiple antennas, the channel estimation of the current AP is The conjugate matrix of the current AP's channel estimation is recorded as When the current AP contains one antenna, the channel estimation of the current AP is The conjugate matrix of the current AP channel estimate is recorded as

[0074] Example 1:

[0075] For the first-level AP, the channel is estimated based on the pilot part of Y1. according to Sure Wherein, R1 is a Hermitian matrix with a dimension of K×K, and the first-level AP transmits X1 and R1 to the second-level AP;

[0076] For the lth level AP, 1<l≤L, according to Y l The pilot part of the channel is used to estimate the channel, and we get according to Sure Among them, R l is a Hermitian matrix with dimension K×K. When l<L, the lth-level AP transmits X to the l+1th-level AP.l and R l ; In the case of l = L, the L-th level AP transmits X to the CPU L and R L .

[0077] The CPU receives the X transmitted by the L-th level AP. L and R L Determine the signal X for demodulation est =R L -1 X L .

[0078] In this example, each level of AP includes multiple antennas, and the first inter-user interference information matrix is ​​the sum of the correlation matrix of the multi-user channel and the noise diagonal matrix. For the first level of AP, first determine the On this basis, calculate and The processes can be performed in parallel, thereby reducing the processing delay during signal transmission.

[0079] Example 2:

[0080] For the first-level AP, the channel is estimated based on the pilot part of Y1. according to Sure Where R1 is a Hermitian matrix of dimension K×K, and the first-level AP transmits X1 and R1 to the second-level AP;

[0081] For the lth level AP, 1<l≤L, according to Y l The pilot part of the channel is used to estimate the channel, and we get according to Sure Among them, R l is a Hermitian matrix with dimension K×K. When l<L, the lth-level AP transmits X to the l+1th-level AP. l and R l ; In the case of l = L, the L-th level AP transmits X to the CPU L and R L .

[0082] The CPU receives the X transmitted by the L-th level AP. L and R L Determine the signal X for demodulation est =(R L +σ 2 I K ) -1 X L .

[0083] In this example, each level of AP includes multiple antennas, and the first inter-user interference information matrix is ​​a correlation matrix of a multi-user channel. For the first level of AP, first determine the pilot part of the received signal. On this basis, calculate and The processes can be performed in parallel, thereby reducing the processing delay during signal transmission.

[0084] Example 3:

[0085] For the first-level AP, the channel is estimated based on the pilot part of Y1. according to Sure Determine using the N-fold Sherman-Morrison formula R1 is a Hermitian matrix with dimension K×K. The first-level AP transmits X1 and R1 to the second-level AP. -1 ;

[0086] For the lth level AP, 1<l≤L, according to Y l The pilot part of the channel is used to estimate the channel, and we get according to Sure Determine using the N-fold Sherman-Morrison formula R l is a Hermitian matrix with dimension K×K. When l<L, the lth-level AP transmits X to the l+1th-level AP. l and R l ; In the case of l = L, the L-th level AP transmits X to the CPU L and R L .

[0087] The CPU receives the X transmitted by the L-th level AP. L and R L Determine the signal X for demodulation est =R L -1 X L .

[0088] In this example, each level of AP includes multiple antennas, and the first inter-user interference information matrix is ​​the inverse matrix of the sum of the correlation matrix of the multi-user channel and the noise diagonal matrix. For the first level of AP, first determine the On this basis, calculate and The processes can be performed in parallel, thereby reducing the processing delay during signal transmission.

[0089] Example 4:

[0090] For the first-level AP, the channel is estimated based on the pilot part of Y1 and the prior information of the correlation matrix of the multi-user channel, and the according to Sure R1 is a Hermitian matrix with a dimension of K×K. The first-level AP transmits X1 and R1 to the second-level AP.

[0091] For the lth level AP, 1<l≤L, according to Y l The pilot part of the channel is used to estimate the channel, and we get according to Sure R l is a Hermitian matrix with dimension K×K. When l<L, the lth-level AP transmits X to the l+1th-level AP. l and R l ; In the case of l = L, the L-th level AP transmits X to the CPU L and R L .

[0092] The CPU receives the X transmitted by the L-th level AP. L and R L Determine the signal X for demodulation est =R L -1 X L .

[0093] In this example, each level of AP includes multiple antennas, and the first inter-user interference information matrix is ​​the sum of the correlation matrix of the multi-user channel and the noise diagonal matrix. For the first level of AP, first determine the pilot part of the received signal and the prior information of the correlation matrix of the multi-user channel. On this basis, calculate and The processes can be performed in parallel, thereby reducing the processing delay during signal transmission.

[0094] Example 5:

[0095] For the first-level AP, the channel is estimated based on the pilot part of Y1. according to Sure R1 is a Hermitian matrix of dimension K×K, and the first-level AP transmits X1 and R1 to the second-level AP;

[0096] For the lth level AP, 1<l≤L, according to Y l The pilot part of the channel is used to estimate the channel, and we get according to Sure Rl is a Hermitian matrix with dimension K×K. When l<L, the lth-level AP transmits X to the l+1th-level AP. l and R l ; In the case of l = L, the L-th level AP transmits X to the CPU L and R L .

[0097] The CPU receives the X transmitted by the L-th level AP. L and R L Determine the signal X for demodulation est =R L -1 X L .

[0098] In this example, each level of AP contains one antenna, and the first inter-user interference information matrix is ​​the sum of the correlation matrix of the multi-user channel and the noise diagonal matrix. For the first level of AP, first determine the pilot part of the received signal On this basis, calculate and The processes can be performed in parallel, thereby reducing the processing delay during signal transmission.

[0099] Example 6:

[0100] For the first-level AP, the channel is estimated based on the pilot part of Y1. according to Sure R1 is a Hermitian matrix with dimension K×K. The first-level AP transmits X1 and R1 to the second-level AP. For the l-th-level AP, 1<l≤L, according to Y l The pilot part of the channel is used to estimate the channel, and we get according to Sure R l is a Hermitian matrix with dimension K×K. When l<L, the lth-level AP transmits X to the l+1th-level AP. l and R l ; In the case of l = L, the L-th level AP transmits X to the CPU L and R L .

[0101] The CPU receives the X transmitted by the L-th level AP. L and R L Determine the signal X for demodulation est =(R L +σ 2 I K ) -1 X L .

[0102] In this example, each level of AP includes one antenna, and the first inter-user interference information matrix is ​​the correlation matrix of the multi-user channel. For the first level of AP, first determine On this basis, calculate and The processes can be performed in parallel, thereby reducing the processing delay during signal transmission.

[0103] Example 7:

[0104] For the first-level AP, the channel is estimated based on the pilot part of Y1. according to Sure Determine using the Sherman-Morrison formula R1 is a Hermitian matrix with dimension K×K. The first-level AP transmits X1 and R1 to the second-level AP. -1 ;

[0105] For the lth level AP, 1<l≤L, according to Y l The pilot part of the channel is used to estimate the channel, and we get according to Sure Determine using the N-fold Sherman-Morrison formula R l is a Hermitian matrix with dimension K×K. When l<L, the lth-level AP transmits X to the l+1th-level AP. l and R l ; In the case of l = L, the L-th level AP transmits X to the CPU L and R L .

[0106] The CPU receives the X transmitted by the L-th level AP. L and R L Determine the signal X for demodulation est =R L -1 X L .

[0107] In this example, each level of AP contains one antenna, and the first inter-user interference information matrix is ​​the inverse matrix of the sum of the correlation matrix of the multi-user channel and the noise diagonal matrix. For the first level of AP, first determine the pilot part of the received signal On this basis, calculate and The processes can be performed in parallel, thereby reducing the processing delay during signal transmission.

[0108] Example 8:

[0109] For the first-level AP, the channel is estimated based on the pilot part of Y1 and the energy prior information of the multi-user channel, and according to Sure R1 is a Hermitian matrix of dimension K×K, and the first-level AP transmits X1 and R1 to the second-level AP;

[0110] For the lth level AP, 1<l≤L, according to Y l The pilot part of the channel is used to estimate the channel, and we get according to Sure R l is a Hermitian matrix with dimension K×K. When l<L, the lth-level AP transmits X to the l+1th-level AP. l and R l ; In the case of l = L, the L-th level AP transmits X to the CPU L and R L .

[0111] The CPU receives the X transmitted by the L-th level AP. L and R L Determine the signal X for demodulation est =R L -1 X L .

[0112] In this example, each level of AP includes one antenna, and the first inter-user interference information matrix is ​​the correlation matrix of the multi-user channel. For the first level of AP, first determine the energy prior information of the pilot part of the received signal and the multi-user channel. On this basis, calculate and The processes can be performed in parallel, thereby reducing the processing delay during signal transmission.

[0113] In an embodiment of the present application, a signal transmission method is also provided, which is applied to a CPU, and the CPU may be a centralized control unit on the network side, such as a CPU, a network management device, a base station, etc. The CPU receives a multi-user uplink data signal transmitted by the last-level AP in the forward return link and a first inter-user interference information matrix, and thereby recovers the signal used for demodulation, improves the demodulation performance, and makes the demodulated signal have a higher signal-to-noise ratio.

[0114] Figure 3 FIG. 1 is a flow chart of another signal transmission method provided by an embodiment. Figure 3 As shown, the method provided in this embodiment includes step 210 and step 220. For technical details not described in detail in this embodiment, please refer to any of the above embodiments.

[0115] In step 210, a multi-user uplink data signal and a first inter-user interference information matrix transmitted by the last-stage AP in the forward backhaul link are received.

[0116] In step 220, a signal for demodulation is determined according to the multi-user uplink data signal and the first inter-user interference information matrix.

[0117] In this embodiment, the multi-user uplink data signal includes uplink data signals sent by multiple terminals to the CPU through the last-level AP, and each uplink data signal contains uplink data transmitted by the corresponding terminal; in addition, it also includes the corresponding multi-user uplink data signal transmitted by the last-level AP of the last-level AP to the last-level AP, that is, the multi-user uplink data signal of the last-level AP is the result of combining the multi-user uplink data signal determined by the last-level AP according to channel estimation with the multi-user uplink data signal corresponding to the last-level AP.

[0118] The first inter-user interference information matrix is ​​used to represent the interference between the uplink data signal sent by each terminal and the uplink data signal sent by other terminals, and is also affected by the first inter-user interference information matrix corresponding to the upper-level AP transmitted by the upper-level AP of the last-level AP, that is, the first inter-user interference information matrix of the last-level AP is the result of combining the first inter-user interference information matrix determined by the last-level AP according to channel estimation and the first inter-user interference information matrix corresponding to the upper-level AP.

[0119] In one embodiment, the signal used for demodulation includes: the product of a first matrix and a multi-user uplink data signal, wherein the first matrix is ​​the inverse matrix of the sum of a first inter-user interference information matrix and a noise diagonal matrix; or, the product of a second matrix and a multi-user uplink data signal, wherein the second matrix is ​​the inverse matrix of the first inter-user interference information matrix.

[0120] The CPU receives the multi-user uplink data signal transmitted by the last level AP (i.e., the L-th level AP in the above example) L ) and the first inter-user interference information matrix (i.e., R in the above example L ), and the signal for demodulation is determined accordingly. For example, the signal for demodulation is the first matrix (R L +σ 2 I K ) -1 With X L The product of X est =(R L +σ 2 I K ) -1 X LIn this case, the first inter-user interference information matrix is ​​the correlation matrix of the multi-user channel; for example, the signal used for demodulation is the second matrix R L -1 With multi-user uplink data signal X L The product of X est =R L -1 X L In this case, the first inter-user interference information matrix is ​​the correlation matrix of the multi-user channel, or the sum of the correlation matrix of the multi-user channel and the noise diagonal matrix, or the inverse matrix of the sum of the correlation matrix of the multi-user channel and the noise diagonal matrix.

[0121] In one embodiment, each AP in the forward backhaul link is provided with at least one antenna;

[0122] The number of row vectors and column vectors of the first inter-user interference information matrix are equal to the number of users;

[0123] The number of row vectors of the multi-user uplink data signal is equal to the number of users, and the number of column vectors is equal to the number of data symbols of the signal received on a single antenna of the current AP.

[0124] In one embodiment, the AP determines the channel estimate based on the pilot portion of the received signal; or, determines the channel estimate based on the pilot portion of the received signal and a priori information of the correlation matrix of the multi-user channel; or, determines the channel estimate based on the pilot portion of the received signal and a priori information of the energy of the multi-user channel.

[0125] In one embodiment, for a first-level AP, a multi-user uplink data signal corresponding to the first-level AP is obtained based on a conjugate matrix of a channel estimation of the first-level AP; for a non-first-level AP, a multi-user uplink data signal corresponding to the non-first-level AP is obtained by superimposing a current multi-user uplink data signal with a multi-user uplink data signal output by an upper-level AP, wherein the current multi-user uplink data signal is obtained based on a conjugate matrix of a channel estimation of the non-first-level AP.

[0126] In one embodiment, for a first-level AP, a first inter-user interference information matrix corresponding to the first-level AP is obtained based on the channel estimation of the first-level AP; for a non-first-level AP, a first inter-user interference information matrix corresponding to the non-first-level AP is obtained by superimposing a current first inter-user interference information matrix and a first inter-user interference information matrix output by the previous-level AP, wherein the current first inter-user interference information matrix is ​​obtained based on the channel estimation of the non-first-level AP.

[0127] In one embodiment, the first inter-user interference information matrix includes one of the following: a correlation matrix of a multi-user channel; a sum of a correlation matrix of a multi-user channel and a noise diagonal matrix; an inverse matrix of the sum of a correlation matrix of a multi-user channel and a noise diagonal matrix.

[0128] In an embodiment of the present application, a signal transmission method is also provided, which is applied to each level of AP in the forward return link. When the CPU sends downlink data signals to multiple terminals through the forward return link of at least one level of AP, the transmission signal is determined according to the acquired multi-user downlink data signal and the interference information matrix between the second users, thereby improving the signal-to-noise ratio of the terminal receiving signal.

[0129] Figure 4 FIG. 1 is a flow chart of another signal transmission method provided by an embodiment. Figure 4 As shown, the method provided in this embodiment includes step 310 and step 320. For technical details not described in detail in this embodiment, please refer to any of the above embodiments.

[0130] In step 310, information related to multi-user downlink data signals and a second inter-user interference information matrix is ​​obtained.

[0131] In step 320, a transmit signal of the current AP is determined according to the multi-user downlink data signal, the related information of the second inter-user interference information matrix, and the channel estimation of the current AP.

[0132] In this embodiment, the multi-user downlink data signal includes a downlink data signal sent by the CPU to multiple terminals through at least one level of AP, and each downlink data signal contains downlink data transmitted to the corresponding terminal; the second inter-user interference information matrix is ​​used to represent the interference between the downlink data signals sent by the CPU to multiple terminals through at least one level of AP.

[0133] In one embodiment, the related information includes: a multi-user downlink data signal and a second inter-user interference information matrix; or a product signal of the multi-user downlink data signal and the second inter-user interference information matrix.

[0134] In one embodiment, the second inter-user interference information matrix includes: an inverse matrix of the sum of a correlation matrix of a multi-user channel and a noise diagonal matrix.

[0135] In one embodiment, when the relevant information includes a multi-user downlink data signal and a second inter-user interference information matrix, the multi-user downlink data signal is sent by a CPU, and the second inter-user interference information matrix is ​​determined by a last-stage AP in a forward backhaul link, or is sent by a CPU;

[0136] In the case where the relevant information includes a product signal of a multi-user downlink data signal and a second inter-user interference information matrix, the product signal is sent by the CPU.

[0137] In this embodiment, in one case, the CPU can send a multi-user downlink data signal to each level of AP, and the way in which each level of AP obtains the second inter-user interference information matrix can be sent by the CPU or determined by the last level of AP in the forward return link (i.e., the Lth level AP, that is, the AP directly connected to the CPU); in another case, the CPU can also send a product signal of the multi-user downlink data signal and the second inter-user interference information matrix to each level of AP, so that each level of AP can determine the transmission signal.

[0138] In one embodiment, the multi-user downlink data signal includes: a multi-user data signal matrix, or a multi-user bit data matrix, wherein the multi-user data signal matrix refers to a matrix composed of modulated data symbols to be sent to multiple users, and the multi-user bit data matrix refers to a matrix composed of bit data to be sent to multiple users.

[0139] In this embodiment, the multi-user downlink data signal may be in the form of a data signal matrix or in the form of a bit data matrix, which can save transmission overhead.

[0140] In one embodiment, it further includes:

[0141] Step 330: When the current AP is the last AP in the forward backhaul link, send a second inter-user interference information matrix to each non-last AP in the forward backhaul link.

[0142] In this embodiment, the last-level AP may determine its own corresponding second inter-user interference information matrix, and send the corresponding second inter-user interference information matrix to each other-level AP in the forward backhaul link.

[0143] In one embodiment, the transmission signal includes: a channel estimate of the current AP, a second inter-user interference information matrix, and a product of a multi-user downlink data signal, or a product of the channel estimate of the current AP and the product signal.

[0144] The signal transmission process is described below by using an example. In the following example, the multi-user data signal matrix is ​​denoted as S, the multi-user bit data matrix is ​​denoted as B, l represents the level of the current AP, l≥1 and l≤L, L is the total number or total level of APs, σ 2 represents the noise of the received signal, I K represents the K×K identity matrix. The second inter-user interference information matrix is ​​recorded as When the current AP contains multiple antennas, the channel estimate of the current AP is recorded as When the current AP contains one antenna, the channel estimate of the current AP is recorded as

[0145] Example 9:

[0146] The CPU sends S and in, T represents the transpose of the matrix;

[0147] For the l-th level AP, 1≤l≤L, according to the received S, as well as Determine the transmitted signal

[0148] In this example, each level of AP includes multiple antennas, and the second inter-user interference information matrix is ​​the inverse matrix of the sum of the correlation matrix of the multi-user channel and the noise diagonal matrix.

[0149] Example 10:

[0150] The CPU sends B to each level of AP, and the Lth level AP sends B to each level of AP in the backhaul link. in, T represents the transpose of the matrix;

[0151] For the l-th level AP, 1≤l≤L, according to the received B, as well as Determine the transmitted signal

[0152] In this example, each level of AP includes multiple antennas, and the second inter-user interference information matrix is ​​the inverse matrix of the sum of the correlation matrix of the multi-user channel and the noise diagonal matrix.

[0153] Example 11:

[0154] The CPU sends S and The product signal of in, T represents the transpose of the matrix;

[0155] For the l-th level AP, 1≤l≤L, according to the received as well as Determine the transmitted signal

[0156] In this example, each level of AP includes multiple antennas, and the second inter-user interference information matrix is ​​the inverse matrix of the sum of the correlation matrix of the multi-user channel and the noise diagonal matrix.

[0157] Example 12:

[0158] The CPU sends S and in, T represents the transpose of the matrix;

[0159] For the l-th level AP, 1≤l≤L, according to the received S, as well as Determine the transmitted signal

[0160] In this example, each level of AP includes one antenna, and the second inter-user interference information matrix is ​​the inverse matrix of the sum of the correlation matrix of the multi-user channel and the noise diagonal matrix.

[0161] Example 13:

[0162] The CPU sends B to each level of AP, and the Lth level AP sends B to each level of AP in the backhaul link. in, T represents the transpose of the matrix;

[0163] For the l-th level AP, 1≤l≤L, according to the received B, as well as Determine the transmitted signal

[0164] In this example, each stage of AP includes one antenna, and the second inter-user interference information matrix is ​​the inverse matrix of the sum of the correlation matrix of the multi-user channel and the noise diagonal matrix.

[0165] Example 14:

[0166] The CPU sends S and The product signal of in, T represents the transpose of the matrix;

[0167] For the l-th level AP, 1≤l≤L, according to the received as well as Determine the transmitted signal

[0168] In this example, each level of AP includes one antenna, and the second inter-user interference information matrix is ​​the inverse matrix of the sum of the correlation matrix of the multi-user channel and the noise diagonal matrix.

[0169] In an embodiment of the present application, a signal transmission method is also provided, which is applied to a CPU, and the CPU may be a centralized control unit on the network side, such as a CPU, a network management device, a main base station, etc. The CPU sends a multi-user downlink data signal to each level of AP, so that each level of AP determines the transmission signal, thereby improving the signal-to-noise ratio of the terminal receiving signal.

[0170] Figure 5FIG. 1 is a flowchart of another signal transmission method provided by an embodiment. Figure 5 As shown, the method provided in this embodiment includes step 410. For technical details not fully described in this embodiment, reference may be made to any of the above embodiments.

[0171] In step 410, a multi-user downlink data signal is sent to each AP in the forward backhaul link, or a product signal of the multi-user downlink data signal and the second inter-user interference information matrix is ​​sent.

[0172] In this embodiment, the multi-user downlink data signal includes a downlink data signal sent by the CPU to multiple terminals through at least one level of AP, and each downlink data signal includes downlink data transmitted to the corresponding terminal.

[0173] In one embodiment, when each AP in the forward backhaul link sends a multi-user downlink data signal, the method further includes:

[0174] Step 420: Send the second inter-user interference information matrix to each stage of AP in the forward backhaul link.

[0175] In this embodiment, the second inter-user interference information matrix is ​​used to represent interference between downlink data signals sent by the CPU to multiple terminals through at least one level of AP.

[0176] In one embodiment, the second inter-user interference information matrix includes: an inverse matrix of the sum of a correlation matrix of a multi-user channel and a noise diagonal matrix.

[0177] In one embodiment, the multi-user downlink data signal includes: a multi-user data signal matrix, or a multi-user bit data matrix.

[0178] The embodiment of the present application also provides a signal transmission device. Figure 6 FIG. 1 is a schematic diagram of a signal transmission device provided by an embodiment. Figure 6 As shown, the signal transmission device includes: a multi-user signal determination module 11 and a first cascade transmission module 12.

[0179] A multi-user signal determination module 11 is configured to determine a multi-user uplink data signal corresponding to the current AP and a first inter-user interference information matrix according to a channel estimation of the current AP;

[0180] The first cascade transmission module 12 is configured to transmit the multi-user uplink data signal and the first inter-user interference information matrix to a next-level node of the current AP in a forward backhaul link.

[0181] The signal transmission device of this embodiment, when multiple terminals send uplink data signals to the CPU through at least one level of AP, improves the reliability of the CPU receiving data signals by transmitting multi-user uplink data signals and a first inter-user interference information matrix on the basis of reducing the load of the forward return link by processing the received data signal sent by each user, and improves the signal-to-noise ratio in the signal transmission process by analyzing and transmitting interference between multiple users.

[0182] In one embodiment, each AP in the forward backhaul link is provided with at least one antenna;

[0183] The number of row vectors and column vectors of the first inter-user interference information matrix are equal to the number of users;

[0184] The number of row vectors of the multi-user uplink data signal is equal to the number of users, and the number of column vectors is equal to the number of data symbols of the signal received on a single antenna of the current AP.

[0185] In one embodiment, an estimation module is further included, configured to:

[0186] Determining the channel estimate based on a pilot portion of a received signal; or,

[0187] Determine the channel estimate based on a pilot part of the received signal and a priori information of a correlation matrix of a multi-user channel; or,

[0188] The channel estimate is determined based on a pilot portion of the received signal and a priori information on energy of a multi-user channel.

[0189] In one embodiment, the multi-user signal determination module 11 includes a first determination unit configured to:

[0190] In the case where the current AP is a first-level AP, obtaining a multi-user uplink data signal corresponding to the current AP according to a conjugate matrix of a channel estimate of the current AP;

[0191] When the current AP is not a first-level AP, a current multi-user uplink data signal is obtained according to the conjugate matrix of the channel estimation of the current AP, and is superimposed with the multi-user uplink data signal output by the upper-level AP of the current AP to obtain the multi-user uplink data signal corresponding to the current AP.

[0192] In one embodiment, the multi-user signal determination module 11 includes a second determination unit configured to:

[0193] In the case where the current AP is a first-level AP, obtaining a first inter-user interference information matrix corresponding to the current AP according to a channel estimation of the current AP;

[0194] In the case where the current AP is not a first-level AP, a current first inter-user interference information matrix is ​​obtained according to the channel estimation of the current AP, and is superimposed with the first inter-user interference information matrix output by the previous-level AP of the current AP to obtain the first inter-user interference information matrix corresponding to the current AP.

[0195] In one embodiment, the first inter-user interference information matrix includes one of the following:

[0196] Correlation matrix of multi-user channels;

[0197] The sum of the correlation matrix of the multi-user channel and the noise diagonal matrix;

[0198] The inverse matrix of the sum of the correlation matrix of the multi-user channel and the noise diagonal matrix.

[0199] The signal transmission device proposed in this embodiment and the signal transmission method applied to AP proposed in the above embodiment belong to the same inventive concept. The technical details not fully described in this embodiment can be referred to any of the above embodiments, and this embodiment has the same beneficial effects as executing the signal transmission method applied to AP.

[0200] The embodiment of the present application also provides a signal transmission device. Figure 7 FIG. 1 is a schematic diagram of the structure of another signal transmission device provided by an embodiment. Figure 7 As shown, the signal transmission device includes: a receiving module 21 and a demodulated signal determination module 22.

[0201] A receiving module 21 is configured to receive a multi-user uplink data signal and a first inter-user interference information matrix transmitted by the last AP in the forward backhaul link;

[0202] The demodulation signal determination module 22 is configured to determine a signal for demodulation according to the multi-user uplink data signal and the first inter-user interference information matrix.

[0203] The signal transmission device of this embodiment receives the multi-user uplink data signal recovered by the last-level AP in the forward return link and the first inter-user interference information matrix, and determines the signal for demodulation based on it, thereby improving the demodulation performance and making the demodulated signal have a higher signal-to-noise ratio.

[0204] In one embodiment, the signal for demodulation includes: the product of a first matrix and a multi-user uplink data signal, wherein the first matrix is ​​the inverse matrix of the sum of a first inter-user interference information matrix and a noise diagonal matrix; or, the product of a second matrix and a multi-user uplink data signal, wherein the second matrix is ​​the inverse matrix of the first inter-user interference information matrix.

[0205] In one embodiment, each AP in the forward backhaul link is provided with at least one antenna;

[0206] The number of row vectors and column vectors of the first inter-user interference information matrix are equal to the number of users;

[0207] The number of row vectors of the multi-user uplink data signal is equal to the number of users, and the number of column vectors is equal to the number of data symbols of the signal received on a single antenna of the current AP.

[0208] In one embodiment, for a first-level AP, a multi-user uplink data signal corresponding to the first-level AP is obtained based on a conjugate matrix of a channel estimation of the first-level AP; for a non-first-level AP, a multi-user uplink data signal corresponding to the non-first-level AP is obtained by superimposing a current multi-user uplink data signal with a multi-user uplink data signal output by an upper-level AP, wherein the current multi-user uplink data signal is obtained based on a conjugate matrix of a channel estimation of the non-first-level AP.

[0209] In one embodiment, for the first-level AP, the first inter-user interference information matrix corresponding to the first-level AP is obtained according to the channel estimation of the first-level AP;

[0210] For a non-first-level AP, the first inter-user interference information matrix corresponding to the non-first-level AP is obtained by superimposing a current first inter-user interference information matrix and a first inter-user interference information matrix output by the previous-level AP, wherein the current first inter-user interference information matrix is ​​obtained based on the channel estimation of the non-first-level AP.

[0211] In one embodiment, the first inter-user interference information matrix includes one of the following:

[0212] Correlation matrix of multi-user channels;

[0213] The sum of the correlation matrix of the multi-user channel and the noise diagonal matrix;

[0214] The inverse matrix of the sum of the correlation matrix of the multi-user channel and the noise diagonal matrix.

[0215] The signal transmission device proposed in this embodiment and the signal transmission method applied to the CPU proposed in the above embodiment belong to the same inventive concept. The technical details not fully described in this embodiment can be referred to any of the above embodiments, and this embodiment has the same beneficial effects as executing the signal transmission method applied to the CPU.

[0216] The embodiment of the present application also provides a signal transmission device. Figure 8 FIG. 1 is a schematic diagram of the structure of another signal transmission device provided by an embodiment. Figure 8 As shown, the signal transmission device includes: an acquisition module 31 and a transmission module 32.

[0217] An acquisition module 31 is configured to acquire information related to a multi-user downlink data signal and a second inter-user interference information matrix;

[0218] The transmitting module 32 is configured to determine the transmitting signal of the current AP according to the multi-user downlink data signal, the relevant information of the second inter-user interference information matrix and the channel estimation of the current AP.

[0219] The signal transmission device of this embodiment determines the transmission signal according to the acquired multi-user downlink data signal and the interference information matrix between the second users, so as to improve the signal-to-noise ratio of the terminal receiving signal when the CPU sends downlink data signals to multiple terminals through the forward return link of at least one level AP.

[0220] In one embodiment, the related information includes: a multi-user downlink data signal and a second inter-user interference information matrix; or a product signal of the multi-user downlink data signal and the second inter-user interference information matrix.

[0221] In one embodiment, the second inter-user interference information matrix includes: an inverse matrix of the sum of a correlation matrix of a multi-user channel and a noise diagonal matrix.

[0222] In one embodiment, the multi-user downlink data signal is sent by a CPU, and the second inter-user interference information matrix is ​​determined by the last-stage AP in the forward backhaul link, or is sent by the CPU;

[0223] The product signal is sent by the CPU.

[0224] In one embodiment, the multi-user downlink data signal includes: a multi-user data signal matrix, or a multi-user bit data matrix.

[0225] In one embodiment, it further includes:

[0226] The second inter-user interference information matrix sending module is configured to send the second inter-user interference information matrix to each non-last AP in the forward backhaul link when the current AP is the last AP in the forward backhaul link.

[0227] In one embodiment, the transmission signal includes: a channel estimate of the current AP, a second inter-user interference information matrix, and a product of a multi-user downlink data signal, or a product of the channel estimate of the current AP and the product signal.

[0228] The signal transmission device proposed in this embodiment and the signal transmission method applied to AP proposed in the above embodiment belong to the same inventive concept. The technical details not fully described in this embodiment can be referred to any of the above embodiments, and this embodiment has the same beneficial effects as executing the signal transmission method applied to AP.

[0229] The embodiment of the present application also provides a signal transmission device. Fig. 9 FIG. 1 is a schematic diagram of the structure of another signal transmission device provided by an embodiment. Fig. 9 As shown, the signal transmission device includes: a second cascade transmission module 41.

[0230] The second cascade transmission module 41 is configured to send a multi-user downlink data signal to each AP in the forward backhaul link, or send a product signal of the multi-user downlink data signal and the second inter-user interference information matrix.

[0231] The signal transmission device of this embodiment improves the signal-to-noise ratio of the terminal receiving signal by sending multi-user downlink data signals to each level of AP so that each level of AP can determine the transmission signal.

[0232] In one embodiment, when each AP in the forward backhaul link sends a multi-user downlink data signal, the method further includes:

[0233] The third cascade transmission module is configured to send a second inter-user interference information matrix to each AP in the forward and backhaul links.

[0234] The signal transmission device proposed in this embodiment and the signal transmission method applied to the CPU proposed in the above embodiment belong to the same inventive concept. The technical details not fully described in this embodiment can be referred to any of the above embodiments, and this embodiment has the same beneficial effects as executing the signal transmission method applied to the CPU.

[0235] The embodiment of the present application further provides an access node, which is, for example, a distributed base station, a baseband processing unit of a base station antenna, etc., and signals are transmitted between multiple terminals and a CPU via at least one level of access nodes. Fig.10 A schematic diagram of the hardware structure of an access node provided by an embodiment is shown in FIG. Fig.10 As shown, the access node provided by the present application includes one or more processors 51, wherein the one or more processors 51 implement the signal transmission method applied to the AP provided by any embodiment of the present application when executed.

[0236] The access node may further include a storage device 52; the processor 51 in the access node may be one or more processors. Fig.10A processor 51 is taken as an example; the storage device 52 is used to store one or more programs; the one or more programs are executed by the one or more processors 51, so that the one or more processors 51 implement the signal transmission method applied to AP as described in the embodiment of the present application.

[0237] The access node further comprises: a communication device 53 , an input device 54 and an output device 55 .

[0238] The processor 51, storage device 52, communication device 53, input device 54 and output device 55 in the access node may be connected via a bus or other means. Fig.10 The example of connecting through bus is taken in the following.

[0239] The input device 54 may be used to receive input digital or character information and generate key signal input related to user settings and function control of the access node. The output device 55 may include display devices such as a display screen.

[0240] The communication device 53 may include a receiver and a transmitter. The communication device 53 is configured to perform information transmission and reception communication according to the control of the processor 51.

[0241] The storage device 52, as a computer-readable storage medium, can be configured to store software programs, computer executable programs and modules, such as program instructions / modules corresponding to the signal transmission method applied to the AP described in the embodiment of the present application (for example, the multi-user signal determination module 11 and the first cascade transmission module 12 in the signal transmission device, and for example, the acquisition module 31 and the transmission module 32 in the signal transmission device). The storage device 52 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created according to the use of the access node, etc. In addition, the storage device 52 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some instances, the storage device 52 may further include a memory remotely arranged relative to the processor 51, and these remote memories may be connected to the access node via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0242] The embodiment of the present application further provides a CPU. The CPU is a centralized control unit on the network side, such as a main base station, a CPU, a network management device, etc. Fig.11 A schematic diagram of the hardware structure of a central processing unit provided in an embodiment is shown in FIG. Fig.11As shown, the CPU provided by the present application includes one or more processors 61, wherein the one or more processors 61 implement the signal transmission method applied to the CPU provided by any embodiment of the present application when executed.

[0243] The CPU may further include a storage device 62; the processor 61 in the CPU may be one or more processors, Fig.11 A processor 61 is taken as an example; the storage device 62 is used to store one or more programs; the one or more programs are executed by the one or more processors 61, so that the one or more processors 61 implement the signal transmission method applied to the CPU as described in the embodiment of the present application.

[0244] The CPU further includes: a communication device 63 , an input device 64 and an output device 65 .

[0245] The processor 61, storage device 62, communication device 63, input device 64 and output device 65 in the CPU can be connected through a bus or other means. Fig.11 The example of connecting through bus is taken in the following.

[0246] The input device 64 can be used to receive input digital or character information and generate key signal input related to the user settings and function control of the CPU. The output device 65 can include display devices such as a display screen.

[0247] The communication device 63 may include a receiver and a transmitter. The communication device 63 is configured to perform information transmission and reception communication according to the control of the processor 61.

[0248] The storage device 62, as a computer-readable storage medium, can be configured to store software programs, computer executable programs and modules, such as program instructions / modules corresponding to the signal transmission method applied to the CPU as described in the embodiment of the present application (for example, the receiving module 21 and the receiving module 22 in the signal transmission device, and for example, the second cascade transmission module 41 in the signal transmission device). The storage device 62 may include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application required for at least one function; the storage data area may store data created according to the use of the CPU, etc. In addition, the storage device 62 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some instances, the storage device 62 may further include a memory remotely arranged relative to the processor 61, and these remote memories may be connected to the CPU via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0249] The embodiment of the present application also provides a signal transmission system. Fig.12 FIG. 1 is a schematic diagram of a signal transmission system provided by an embodiment. Fig.12 As shown, the system includes: a central processing unit 71, at least one access node 72 described in any of the above embodiments, and at least two terminals 73; signals are transmitted between the central processing unit 71 and each terminal via at least one access node 72.

[0250] In the signal transmission system of this embodiment, when multiple terminals send uplink data signals to the CPU through at least one level of AP, each level of AP in the forward return link processes the received data signal of each user to reduce the load of the forward return link, and provides more information for the CPU's signal processing by transmitting multi-user uplink data signals and the first inter-user interference information matrix, thereby improving the signal-to-noise ratio of the CPU received signal; the CPU receives the multi-user uplink data signal restored by the last level of AP in the forward return link and the first inter-user interference information matrix, and determines the signal for demodulation based on this, thereby improving the demodulation performance and making the demodulated signal have a higher signal-to-noise ratio.

[0251] When the CPU sends downlink data signals to multiple terminals through the forward return link of at least one level of AP, each level of AP determines the transmission signal based on the acquired multi-user downlink data signal and the interference information matrix between the second users, thereby improving the signal-to-noise ratio of the terminal receiving signal; the CPU sends multi-user downlink data signals to each level of AP, so that each level of AP determines the transmission signal, thereby improving the signal-to-noise ratio of the terminal receiving signal.

[0252] In one embodiment, each level of AP determines a multi-user uplink data signal and a first inter-user interference information matrix corresponding to the current AP based on a channel estimation of the current AP; and transmits the multi-user uplink data signal and the first inter-user interference information matrix to a next level node of the current AP in a forward backhaul link.

[0253] In one embodiment, each AP in the forward backhaul link is provided with at least one antenna;

[0254] The number of row vectors and column vectors of the first inter-user interference information matrix are equal to the number of users;

[0255] The number of row vectors of the multi-user uplink data signal is equal to the number of users, and the number of column vectors is equal to the number of data symbols of the signal received on a single antenna of the current AP.

[0256] In one embodiment, each level of AP determines the channel estimate based on the pilot part of the received signal; or, determines the channel estimate based on the pilot part of the received signal and the correlation matrix prior information of the multi-user channel; or, determines the channel estimate based on the pilot part of the received signal and the energy prior information of the multi-user channel.

[0257] In one embodiment, a multi-user uplink data signal corresponding to the current AP is determined based on the channel estimation of the current AP, including: when the current AP is a first-level AP, the multi-user uplink data signal corresponding to the current AP is obtained based on the conjugate matrix of the channel estimation of the current AP; when the current AP is not a first-level AP, a current multi-user uplink data signal is obtained based on the conjugate matrix of the channel estimation of the current AP, and it is superimposed with the multi-user uplink data signal output by the upper-level AP of the current AP to obtain the multi-user uplink data signal corresponding to the current AP.

[0258] In one embodiment, determining a first inter-user interference information matrix according to a channel estimation of a current AP includes:

[0259] When the current AP is a first-level AP, a first inter-user interference information matrix corresponding to the current AP is obtained based on the channel estimation of the current AP; when the current AP is not a first-level AP, a current first inter-user interference information matrix is ​​obtained based on the channel estimation of the current AP, and is superimposed with the first inter-user interference information matrix output by the upper-level AP of the current AP to obtain the first inter-user interference information matrix corresponding to the current AP.

[0260] In one embodiment, the first inter-user interference information matrix includes one of the following: a correlation matrix of a multi-user channel; a sum of a correlation matrix of a multi-user channel and a noise diagonal matrix; an inverse matrix of the sum of a correlation matrix of a multi-user channel and a noise diagonal matrix.

[0261] In one embodiment, the CPU receives a multi-user uplink data signal and a first inter-user interference information matrix transmitted by the last-level AP in the forward return link; and determines a signal for demodulation according to the multi-user uplink data signal and the first inter-user interference information matrix.

[0262] In one embodiment, the signal for demodulation includes: the product of a first matrix and a multi-user uplink data signal, wherein the first matrix is ​​the inverse matrix of the sum of a first inter-user interference information matrix and a noise diagonal matrix; or, the product of a second matrix and a multi-user uplink data signal, wherein the second matrix is ​​the inverse matrix product of the first inter-user interference information matrix.

[0263] In one embodiment, each level of AP obtains relevant information of a multi-user downlink data signal and a second inter-user interference information matrix; and determines a transmission signal of the current AP based on the relevant information of the multi-user downlink data signal and the second inter-user interference information matrix and a channel estimate of the current AP.

[0264] In one embodiment, the related information includes: a multi-user downlink data signal and a second inter-user interference information matrix; or a product signal of the multi-user downlink data signal and the second inter-user interference information matrix.

[0265] In one embodiment, the second inter-user interference information matrix includes: an inverse matrix of the sum of a correlation matrix of a multi-user channel and a noise diagonal matrix.

[0266] In one embodiment, the multi-user downlink data signal is sent by the CPU, and the second inter-user interference information matrix is ​​determined by the last-stage AP in the forward backhaul link, or is sent by the CPU;

[0267] The product signal is sent by the CPU.

[0268] In one embodiment, the multi-user downlink data signal includes: a multi-user data signal matrix, or a multi-user bit data matrix.

[0269] In one embodiment, when the current AP is the last-stage AP in the forward backhaul link, the second inter-user interference information matrix is ​​sent to each non-last-stage AP in the forward backhaul link respectively.

[0270] In one embodiment, the transmission signal includes: a channel estimate of the current AP, a second inter-user interference information matrix, and a product of a multi-user downlink data signal, or a product of the channel estimate of the current AP and the product signal.

[0271] In one embodiment, the CPU sends a multi-user downlink data signal to each stage of AP in the forward backhaul link, or sends a product signal of the multi-user downlink data signal and the second inter-user interference information matrix.

[0272] In one embodiment, when sending a multi-user downlink data signal to each stage of AP in the forward backhaul link, the CPU further sends a second inter-user interference information matrix to each stage of AP in the forward backhaul link.

[0273] An embodiment of the present application further provides a storage medium, wherein the storage medium stores a computer program, and when the computer program is executed by a processor, the signal transmission method described in any one of the embodiments of the present application is implemented.

[0274] The signal transmission method includes: determining a multi-user uplink data signal and a first inter-user interference information matrix corresponding to the current AP according to the channel estimation of the current AP; transmitting the multi-user uplink data signal and the first inter-user interference information matrix to the next level node of the current AP in the forward return link.

[0275] Alternatively, a signal transmission method includes: receiving a multi-user uplink data signal and a first inter-user interference information matrix transmitted by the last level AP in a forward return link; and determining a signal for demodulation based on the multi-user uplink data signal and the first inter-user interference information matrix.

[0276] Alternatively, the signal transmission method includes: obtaining relevant information of a multi-user downlink data signal and a second inter-user interference information matrix; determining a transmission signal of the current AP based on the relevant information of the multi-user downlink data signal and the second inter-user interference information matrix and a channel estimate of the current AP.

[0277] Alternatively, the signal transmission method includes: sending a multi-user downlink data signal to each level of AP in the forward backhaul link, or sending a product signal of the multi-user downlink data signal and a second inter-user interference information matrix.

[0278] It should be noted that the process of multiple terminals sending uplink data signals to the CPU through at least one level of AP and the CPU sending downlink data signals to multiple terminals through at least one level of AP can be carried out simultaneously. For example, on the one hand, the CPU receives and demodulates the multi-user uplink data signal and the first inter-user interference information matrix transmitted by the last level of AP, and on the other hand, it also sends multi-user downlink data signals to each level of AP.

[0279] The computer storage medium of the embodiment of the present application can adopt any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium can be, for example, but not limited to: an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples (non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (Random Access Memory, RAM), a read-only memory (Read Only Memory, ROM), an erasable programmable read-only memory (ErasableProgrammable Read Only Memory, EPROM), a flash memory, an optical fiber, a portable CD-ROM, an optical storage device, a magnetic storage device, or any suitable combination of the above. The computer-readable storage medium can be any tangible medium containing or storing a program, which can be used by an instruction execution system, a device or a device or used in combination with it.

[0280] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, which carry computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to: electromagnetic signals, optical signals, or any suitable combination of the above. Computer-readable signal media may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0281] The program code contained on the computer-readable medium may be transmitted using any appropriate medium, including but not limited to: wireless, wire, optical cable, radio frequency (RF), etc., or any suitable combination of the above.

[0282] The computer program code for performing the operation of the present application can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages, such as Java, Smalltalk, C++, and also conventional procedural programming languages, such as "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as an independent software package, partially on the user's computer and partially on the remote computer, or completely on the remote computer or server. In the case of a remote computer, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computer (e.g., using an Internet service provider to connect through the Internet).

[0283] The above description is merely an exemplary embodiment of the present application and is not intended to limit the protection scope of the present application.

[0284] It will be appreciated by those skilled in the art that the term user terminal covers any suitable type of wireless user equipment, such as a mobile phone, a portable data processing device, a portable web browser or a vehicle-mounted mobile station.

[0285] In general, various embodiments of the present application can be implemented in hardware or dedicated circuits, software, logic or any combination thereof. For example, some aspects can be implemented in hardware, while other aspects can be implemented in firmware or software that can be executed by a controller, microprocessor or other computing device, although the present application is not limited thereto.

[0286] Embodiments of the present application may be implemented by executing computer program instructions by a data processor of a mobile device, for example in a processor entity, or by hardware, or by a combination of software and hardware. The computer program instructions may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages.

[0287] The block diagram of any logic flow in the drawings of the present application may represent program steps, or may represent interconnected logic circuits, modules and functions, or may represent a combination of program steps and logic circuits, modules and functions. A computer program may be stored on a memory. The memory may have any type suitable for the local technical environment and may be implemented using any suitable data storage technology, such as but not limited to read-only memory (ROM), random access memory (RAM), optical memory devices and systems (digital versatile discs (DVD) or compact disks (CD)), etc. Computer-readable media may include non-transient storage media. A data processor may be any type suitable for the local technical environment, such as but not limited to a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FGPAs) and a processor based on a multi-core processor architecture.

[0288] By way of exemplary and non-limiting examples, a detailed description of exemplary embodiments of the present application has been provided above. However, various modifications and adjustments to the above embodiments will be apparent to those skilled in the art when considered in conjunction with the accompanying drawings and claims, but will not depart from the scope of the present application. Therefore, the proper scope of the present application will be determined according to the claims.

Claims

1. A signal transmission method, applied to a current access node AP, characterized in that: include: Determine, according to the channel estimation of the current access node AP, a multi-user uplink data signal corresponding to the current AP and a first inter-user interference information matrix; Transmitting the multi-user uplink data signal and the first inter-user interference information matrix to a next-level node of the current AP in a forward backhaul link; The first inter-user interference information matrix is ​​determined according to the channel estimation of the current AP, including: In the case where the current AP is a first-level AP, obtaining a first inter-user interference information matrix corresponding to the current AP according to a channel estimation of the current AP; In the case where the current AP is not a first-level AP, a current first inter-user interference information matrix is ​​obtained according to the channel estimation of the current AP, and is superimposed with the first inter-user interference information matrix output by the previous-level AP of the current AP to obtain the first inter-user interference information matrix corresponding to the current AP.

2. The method according to claim 1, characterized in that Each level of AP in the forward return link is provided with at least one antenna; The number of row vectors and column vectors of the first inter-user interference information matrix are equal to the number of users; The number of row vectors of the multi-user uplink data signal is equal to the number of users, and the number of column vectors is equal to the number of data symbols of the signal received on a single antenna of the current AP.

3. The method according to claim 1, characterized in that: Also includes: determining the channel estimate based on a pilot portion of a received signal; or, Determining the channel estimate based on a pilot portion of the received signal and a priori information of a correlation matrix of a multi-user channel; or, The channel estimate is determined based on a pilot portion of the received signal and a priori information on energy of a multi-user channel.

4. The method according to claim 1, characterized in that: Determining a multi-user uplink data signal corresponding to the current AP according to a channel estimation of the current AP includes: In the case where the current AP is a first-level AP, obtaining a multi-user uplink data signal corresponding to the current AP according to a conjugate matrix of a channel estimate of the current AP; When the current AP is not a first-level AP, a current multi-user uplink data signal is obtained according to the conjugate matrix of the channel estimation of the current AP, and is superimposed with the multi-user uplink data signal output by the upper-level AP of the current AP to obtain the multi-user uplink data signal corresponding to the current AP.

5. The method according to claim 1, characterized in that The first inter-user interference information matrix includes one of the following: Correlation matrix of multi-user channels; The sum of the correlation matrix of the multi-user channel and the noise diagonal matrix; The inverse matrix of the sum of the correlation matrix of the multi-user channel and the noise diagonal matrix.

6. The method according to claim 1, characterized in that Also includes: Obtaining information related to a multi-user downlink data signal and a second user inter-interference information matrix; The transmission signal of the current AP is determined according to the related information of the multi-user downlink data signal and the second inter-user interference information matrix and the channel estimation of the current AP.

7. The method according to claim 6, characterized in that The related information includes: a multi-user downlink data signal and a second inter-user interference information matrix; or a product signal of the multi-user downlink data signal and the second inter-user interference information matrix.

8. The method according to claim 6, characterized in that The second inter-user interference information matrix includes: The inverse matrix of the sum of the correlation matrix of the multi-user channel and the noise diagonal matrix.

9. The method according to claim 7, characterized in that: The multi-user downlink data signal is sent by a central processing unit CPU; The second inter-user interference information matrix is ​​determined by the last AP in the forward backhaul link, or is sent by the CPU; The product signal is sent by the CPU.

10. The method according to claim 6, characterized in that The multi-user downlink data signal includes: A multi-user data signal matrix, or a multi-user bit data matrix.

11. The method according to claim 6, characterized in that Also includes: In the case that the current AP is the last-stage AP in the forward backhaul link, the second inter-user interference information matrix is ​​sent to each non-last-stage AP in the forward backhaul link respectively.

12. The method according to claim 7, characterized in that The transmission signal includes: The product of the channel estimate of the current AP, the second inter-user interference information matrix, and the multi-user downlink data signal; or, the product of the channel estimate of the current AP and the product signal.

13. A signal transmission method, applied to a central processing unit (CPU), characterized in that: include: Receiving a multi-user uplink data signal and a first inter-user interference information matrix transmitted by the last AP in the forward return link; Determine a signal for demodulation according to the multi-user uplink data signal and the first inter-user interference information matrix; The first inter-user interference information matrix of the last-level AP is a result of combining the first inter-user interference information matrix determined by the last-level AP according to channel estimation with the first inter-user interference information matrix corresponding to the previous-level AP.

14. The method according to claim 13, characterized in that The signal for demodulation includes: The product of a first matrix and the multi-user uplink data signal, wherein the first matrix is ​​the inverse matrix of the sum of the first inter-user interference information matrix and the noise diagonal matrix; or The product of a second matrix and the multi-user uplink data signal, wherein the second matrix is ​​an inverse matrix of the first inter-user interference information matrix.

15. The method according to claim 14, characterized in that Also includes: A multi-user downlink data signal is sent to each AP in the forward backhaul link, or a product signal of the multi-user downlink data signal and the second inter-user interference information matrix is ​​sent.

16. The method according to claim 15, characterized in that In the case where each AP in the forward and backhaul links sends a multi-user downlink data signal, the method further includes: The second inter-user interference information matrix is ​​sent to each stage of AP in the forward and backhaul links.

17. A signal transmission device, applied to a current access node AP, characterized in that: include: A multi-user signal determination module, configured to determine a multi-user uplink data signal corresponding to the current AP and a first inter-user interference information matrix according to a channel estimation of the current AP; A first cascade transmission module, configured to transmit the multi-user uplink data signal and the first inter-user interference information matrix to a next-level node of the current AP in a forward backhaul link; Wherein, the multi-user signal determination module is specifically configured as: In the case where the current AP is a first-level AP, obtaining a first inter-user interference information matrix corresponding to the current AP according to a channel estimation of the current AP; In the case where the current AP is not a first-level AP, a current first inter-user interference information matrix is ​​obtained according to the channel estimation of the current AP, and is superimposed with the first inter-user interference information matrix output by the previous-level AP of the current AP to obtain the first inter-user interference information matrix corresponding to the current AP.

18. A signal transmission device, applied to a central processing unit (CPU), characterized in that: include: A receiving module, configured to receive a multi-user uplink data signal and a first inter-user interference information matrix transmitted by a last-stage AP in a forward return link; a demodulation signal determination module, configured to determine a signal for demodulation according to the multi-user uplink data signal and the first inter-user interference information matrix; The first inter-user interference information matrix of the last-level AP is a result of combining the first inter-user interference information matrix determined by the last-level AP according to channel estimation with the first inter-user interference information matrix corresponding to the previous-level AP.

19. An access node AP, characterized in that: include: one or more processors; A storage device for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the signal transmission method according to any one of claims 1 to 12.

20. A central processing unit (CPU), characterized in that: include: one or more processors; A storage device for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the signal transmission method according to any one of claims 13 to 16.

21. A signal transmission system, characterized in that: include: A central processing unit CPU as claimed in claim 20, at least one access node AP as claimed in claim 19, and at least two terminals; The CPU transmits signals to each terminal via at least one level of AP.

22. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the signal transmission method according to any one of claims 1 to 16 is implemented.

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