Channel estimation method and apparatus, network device, terminal device, and storage medium

Abstract

The application provides a channel estimation method and device, network equipment, terminal equipment and storage medium, and relates to the technical field of communication. The method comprises the following steps: performing channel estimation on a channel corresponding to a direct user equipment according to a first pilot signal transmitted by the direct user equipment, to obtain a channel estimation result; grouping the direct user equipment according to the channel estimation result, to obtain at least one first user group and a second user group; receiving a second pilot signal transmitted by a target reflection user equipment based on the first user group; and performing channel estimation on a channel corresponding to the target reflection user equipment according to the second pilot signal. The scheme of the embodiment of the application receives the second pilot signal based on the null space of the first user group, avoids the influence of the first user group on the reflection user equipment and the user equipment in the second user group, and improves the accuracy of channel estimation on the reflection user equipment.

Description

Technical Field

[0001] This invention relates to the field of communication technology, and in particular to a channel estimation method, apparatus, network equipment, terminal equipment, and storage medium. Background Technology

[0002] Existing channel estimation methods in smart reflector-assisted wireless communication systems mainly include separate estimation and joint estimation of the reflected channels between users and base stations. Separate estimation estimates the channels between users and smart reflectors, and between smart reflectors and base stations. Joint estimation estimates the channels between users and smart reflectors, and between smart reflectors and base stations, as cascaded channels. Currently, most research tends to estimate cascaded channels. To ensure the accuracy of channel estimation, both direct users and reflecting users need to be considered simultaneously. Existing technologies use null space interference cancellation while performing channel estimation, but the number of direct users considered must be less than the number of base station antennas. When the number of direct users is large, it can easily lead to inaccurate channel estimation. Summary of the Invention

[0003] The purpose of this invention is to provide a channel estimation method, apparatus, network device, terminal device, and storage medium to solve the problem that in the prior art, when the number of direct users considered is large, channel estimation is prone to inaccuracy.

[0004] To achieve the above objectives, embodiments of the present invention provide a channel estimation method applied to a base station, the method comprising:

[0005] Based on the first pilot signals sent by multiple direct user equipments, channel estimation is performed on the channel corresponding to the direct user equipment to obtain the channel estimation result. The direct user equipment is a user equipment that has a direct link with the base station.

[0006] Based on the channel estimation results, the direct user equipment is grouped to obtain at least one first user group and one second user group;

[0007] Based on the first user group receiving the second pilot signal sent by the target reflecting user equipment, the target reflecting user equipment includes the reflecting user and the direct user equipment in the second user group;

[0008] Channel estimation is performed on the channel corresponding to the target reflecting user equipment based on the second pilot signal.

[0009] Furthermore, the first user group includes: the direct user equipment with a signal-to-noise ratio higher than a preset value;

[0010] The second user group refers to the user equipment other than the first user group among the direct user equipment.

[0011] Further, the step of performing channel estimation on the channel corresponding to the direct user equipment based on the first pilot signals transmitted by multiple direct user equipments to obtain the channel estimation result includes:

[0012] Based on the first pilot signal, channel estimation is performed on the channel corresponding to the direct user equipment to obtain a channel estimation result including signal-to-noise ratio and channel vector.

[0013] Further, the step of grouping the direct user equipment into at least one first user group and a second user group based on the channel estimation result includes:

[0014] Based on the singular value decomposition (SVD) of the channel vector or the orthogonal QR decomposition of the channel vector, the direct user equipment is grouped to obtain at least one first user group and one second user group.

[0015] Further, the grouping of the direct user equipment based on the singular value decomposition (SVD) of the channel vector to obtain at least one first user group and one second user group includes:

[0016] The channel vectors are decomposed using Singular Value Decomposition (SVD) to obtain the singular values ​​of each channel vector.

[0017] The direct user equipment corresponding to the channel vector with the largest singular value is designated as the first user equipment in the first user group;

[0018] Singular Value Decomposition (SVD) is performed on the channel matrix to determine other users within the first user group;

[0019] The user equipment in the direct user equipment, excluding the first user group, is divided into the second user group;

[0020] The channel matrix is ​​generated based on the channel vectors of the third user equipment and the fourth user equipment. The third user equipment refers to all the direct user equipment within the first user group, and the fourth user equipment refers to the direct user equipment outside the first user group.

[0021] Further, the step of performing singular value decomposition (SVD) on the channel matrix to determine other users within the first user group includes:

[0022] The target user device is selected as another user in the first user group by the user grouping criterion of maximizing the minimum singular value;

[0023] Repeat the selection of the target user equipment until the number of user equipment in the first user group reaches a preset threshold.

[0024] The user grouping criterion for maximizing the minimum singular value is as follows:

[0025] The channel vectors of the third user equipment and the fourth user equipment are combined to obtain multiple channel matrices.

[0026] Perform singular value decomposition (SVD) on the channel matrix to determine the minimum singular value of each channel matrix;

[0027] The target user equipment corresponding to the channel matrix with the largest minimum singular value is assigned to the first user group.

[0028] Further, the step of grouping the direct user equipment based on the orthogonal QR decomposition of the channel vector to obtain at least one first user group and one second user group includes:

[0029] Calculate the norm of the channel vector, and take the direct user equipment corresponding to the channel vector with the largest norm as the first user equipment in the first user group;

[0030] Perform orthogonal QR decomposition on the channel matrix to determine other users within the first user group;

[0031] The user equipment in the direct user equipment, excluding the first user group, is divided into the second user group;

[0032] The channel matrix is ​​generated based on the channel vectors of the third user equipment and the fourth user equipment. The third user equipment refers to all the direct user equipment within the first user group, and the fourth user equipment refers to the direct user equipment outside the first user group.

[0033] Further, the step of performing orthogonal QR decomposition on the channel matrix to determine other users within the first user group includes:

[0034] The target user equipment is selected as other users in the first user group based on the target grouping criteria.

[0035] Repeatedly select the target user equipment until the number of users in the first user group reaches a preset threshold.

[0036] The target grouping criteria are as follows:

[0037] Calculate the orthogonal vector between the channel vector of the third user equipment and the channel vector of the fourth user equipment to obtain multiple target orthogonal vectors;

[0038] Calculate the norm of each target orthogonal vector, and assign the target user equipment corresponding to the target orthogonal vector with the largest norm to the first user group.

[0039] Further, the step of receiving the second pilot signal transmitted by the direct user equipment in the second user group based on the first user group includes:

[0040] The first channel matrix is ​​determined based on the channel vectors of the direct user equipment in the first user group;

[0041] Based on the first channel matrix, determine the null space corresponding to the first user group;

[0042] The second pilot signal is received in the null space.

[0043] To achieve the above objectives, embodiments of the present invention provide a channel estimation apparatus, comprising:

[0044] The first processing module is used to perform channel estimation on the channel corresponding to the direct user equipment based on the first pilot signal sent by multiple direct user equipments, and obtain the channel estimation result. The direct user equipment is a user equipment that has a direct link with the base station.

[0045] The grouping module is used to group the direct user equipment according to the channel estimation results to obtain at least one first user group and one second user group.

[0046] The receiving module is configured to receive a second pilot signal transmitted by a target reflecting user equipment based on the first user group, wherein the target reflecting user equipment includes reflecting users and direct user equipment within the second user group;

[0047] The second processing module is used to perform channel estimation on the channel corresponding to the target reflecting user equipment based on the second pilot signal.

[0048] To achieve the above objectives, embodiments of the present invention provide a network device, including a processor and a transceiver, wherein,

[0049] The processor is used to perform channel estimation on the channel corresponding to the direct user equipment based on the first pilot signal sent by multiple direct user equipments, and obtain the channel estimation result. The direct user equipment is a user equipment that has a direct link with the base station.

[0050] Based on the channel estimation results, the direct user equipment is grouped to obtain at least one first user group and one second user group;

[0051] The transceiver is used to receive a second pilot signal transmitted by a target reflecting user equipment based on the first user group, wherein the target reflecting user equipment includes reflecting users and direct user equipment within the second user group;

[0052] The processor is further configured to perform channel estimation for the channel corresponding to the target reflecting user equipment based on the second pilot signal.

[0053] To achieve the above objectives, embodiments of the present invention provide a terminal device, including a transceiver, a processor, a memory, and a program or instructions stored in the memory and executable on the processor; when the processor executes the program or instructions, it implements the channel estimation method as described above.

[0054] To achieve the above objectives, embodiments of the present invention provide a readable storage medium having a program or instructions stored thereon, which, when executed by a processor, implement the steps in the channel estimation method as described above.

[0055] The beneficial effects of the above-described technical solution of the present invention are as follows:

[0056] The channel estimation method of this invention estimates the channel corresponding to the direct user equipment based on the first pilot signal received from the direct user equipment. Then, based on the obtained channel estimation results, the direct user equipment is grouped and filtered, and the filtered direct user equipment is designated as reflecting user equipment. The second pilot signal is received based on the first user group, thus avoiding the influence of the first user group on the reflecting user equipment and user equipment within the second user group, and improving the accuracy of channel estimation for the reflecting user equipment. Attached Figure Description

[0057] Figure 1 This is a schematic diagram illustrating the steps of the channel estimation method according to an embodiment of the present invention;

[0058] Figure 2 This is a logical schematic diagram of the channel estimation method according to an embodiment of the present invention;

[0059] Figure 3 This is a schematic diagram of a ZF-based user equipment grouping scheme according to an embodiment of the present invention;

[0060] Figure 4 This is a schematic diagram of a QR-based user equipment grouping scheme according to an embodiment of the present invention;

[0061] Figure 5 This is a schematic diagram of the channel estimation device according to an embodiment of the present invention;

[0062] Figure 6 This is a schematic diagram of the network device according to an embodiment of the present invention;

[0063] Figure 7 This is a schematic diagram of the structure of a terminal device according to an embodiment of the present invention. Detailed Implementation

[0064] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0065] It should be understood that the phrase "one embodiment" or "an embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of the invention. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments.

[0066] In various embodiments of the present invention, it should be understood that the sequence number of each process described below does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0067] In addition, the terms "system" and "network" are often used interchangeably in this article.

[0068] In the embodiments provided in this application, it should be understood that "B corresponding to A" means that B is associated with A, and B can be determined based on A. However, it should also be understood that determining B based on A does not mean determining B solely based on A; B can also be determined based on A and / or other information.

[0069] It should be noted that in multi-antenna receivers, multi-user interference needs to be eliminated to achieve spatial multiplexing. Zero-Forcing (ZF) receivers are a common type of linear receiver. The main principle of a ZF receiver is to force unnecessary interference information to zero, effectively eliminating inter-symbol interference. Its algorithm complexity is relatively low, and its performance at medium to high signal-to-noise ratios is close to that of minimum mean square error (MMSE) receivers.

[0070] The ZF algorithm is implemented as follows:

[0071] For the equation: y = Ax + z;

[0072] The result after applying the zero-forcing algorithm is as follows:

[0073] After zero-forcing reception, an unbiased estimate of the signal can be obtained, enabling spatial multiplexing and greatly improving the system's spectral efficiency. Furthermore, matrix decomposition algorithms, such as Singular Value Decomposition (SVD) and QR decomposition, are widely used in multi-antenna processing.

[0074] Singular Value Decomposition (SVD) refers to the operation of representing a non-zero m×n matrix A as a product of the following three matrices, i.e., performing matrix factorization: A = U∑V H ;

[0075] Where U is an m-order orthogonal identity matrix, V is an n-order orthogonal identity matrix, and ∑ is an m×n rectangular diagonal matrix composed of non-negative diagonal elements arranged in descending order.

[0076] ZF receiver implementation:

[0077] Assume the base station receives a signal of y = Hx + n;

[0078] Where H is the channel matrix of the direct user group, singular value decomposition of H yields...

[0079]

[0080] Where U and V are M×M and L respectively. max ×L max The unitary matrix, ∑ is M×L max A diagonal matrix containing singular values. The receiver matrix of the ZF receiver can be represented as: G ZF =(H H H) -1 H H ;

[0081] The ZF estimate of the transmitted signal vector x can be expressed as:

[0082] in The covariance matrix of this vector is:

[0083]

[0084] Based on the above derivation, the signal-to-interference-plus-noise ratio (SINR) of the l-th user signal can be obtained as follows:

[0085]

[0086] Substituting the singular value decomposition of the channel matrix H into the above equation, we obtain the expression for SINR as follows:

[0087]

[0088] Since the statistical characteristics of each user signal are the same, the subscript l of SINR can be removed. Then, based on the characteristics of matrix V and ∑, the SINR can be obtained as follows:

[0089]

[0090] Gram-Schmidt orthogonalization:

[0091] Given a matrix H = [a, b, c], where a, b, c are linearly independent column vectors of the matrix, first orthogonalize them to A, B, C, and then normalize them to obtain unit orthogonal vectors q1, q2, q3.

[0092] (1) A = a, the direction of the first vector remains unchanged;

[0093] (2) Subtracting the projection of the second vector onto the first vector results in vector B, which is orthogonal to A.

[0094] (3) The third vector minus its projection onto the plane formed by the first two vectors results in vector C, which is orthogonal to the plane formed by A and B. Therefore, A, B, and C are all orthogonal to each other.

[0095] (4) Normalize the resulting orthogonal vectors as follows:

[0096] The matrix Q = [q1 q2 q3], composed of the orthogonal vectors q1, q2, and q3 obtained after orthogonalization, is the matrix Q in H = QR obtained by QR decomposition of H. Matrix R is the coefficient matrix projected from the column vectors of H to the column vectors of Q. It is an upper triangular matrix with the following specific form:

[0097]

[0098] The diagonal elements are as follows:

[0099] Continuous interference cancellation based on QR reception:

[0100] Assume the base station receives the signal as: y = Hx + n;

[0101] The QR decomposition of the channel matrix H yields: H = QR;

[0102] Where Q is a high-order orthogonal matrix, and R is an upper triangular square matrix, as shown below:

[0103]

[0104] Multiply the received signal by Q on the left H ,have to:

[0105] in The above formula can be equivalently written as:

[0106]

[0107] Among them, [R] lLet represent the l-th diagonal element of matrix R. As can be seen from the above equation, the signal of the l-th user will be interfered with by the signals of the users following it. To eliminate this interference, a continuous interference cancellation method is used, estimating the user signals sequentially from the last to the first. max The signal estimate for each user is:

[0108]

[0109] The function q = Quant(t) determines q as the constellation point closest to t. Substituting the estimated signal into the above... To eliminate its effect on L max The signal interference from -1 user can be estimated sequentially to obtain...

[0110]

[0111] Where l = L max -1,L max -2, ..., 1.

[0112] like Figure 1 As shown, an embodiment of the present invention provides a channel estimation method applied to a base station, the method comprising the following steps:

[0113] Step 101: Based on the first pilot signals sent by multiple direct user equipments, perform channel estimation on the channel corresponding to the direct user equipment to obtain the channel estimation result. The direct user equipment is a user equipment that has a direct link with the base station.

[0114] Step 102: Based on the channel estimation results, group the direct user equipment to obtain at least one first user group and one second user group;

[0115] Step 103: Based on the first user group receiving the second pilot signal sent by the target reflecting user equipment, the target reflecting user equipment includes the reflecting user and the direct user equipment in the second user group;

[0116] Step 104: Perform channel estimation on the channel corresponding to the target reflecting user equipment based on the second pilot signal.

[0117] Optionally, the method further includes:

[0118] Constructing a system model and channel modeling assisted by an Intelligent Reflecting Surface (IRS);

[0119] The base station establishes a connection with the user equipment and determines that the user equipment is a direct user equipment or a reflective user equipment.

[0120] Optionally, the direct link is a link between a user and a base station that does not involve IRS directional reflection;

[0121] The reflection link is the link formed between the user and the base station through directional reflection from the IRS;

[0122] The reflected user equipment is a user equipment that has only a reflected link with the base station.

[0123] In one embodiment of the present invention, the system model includes a base station and its number of antennas M, a smart reflector and its number of components N, direct user equipment with a direct link to the base station and its number L1, and reflective user equipment with only a reflective link to the base station and its number L2.

[0124] Regarding channel modeling: Since the smart reflector and the base station are basically fixed, the coherence time of the channel between the smart reflector and the base station is relatively long, and the channel remains almost unchanged over a long period of time; due to the mobility of user equipment, it is assumed that the channel between the user and the base station and the channel between the user and the smart reflector follow a first-order autoregressive model, and the channel is block fading with a short coherence time.

[0125] Optionally, the step of performing channel estimation for the channel corresponding to the target reflecting user equipment based on the second pilot signal includes:

[0126] Based on the second pilot signal and the changing characteristics of the channel, the observation equation and the channel change equation are combined into a set of equations. Then, Kalman filtering or compressed sensing methods are applied to estimate the channel corresponding to the target reflecting user equipment in the set of equations.

[0127] The channel estimation method of this invention estimates the channel corresponding to the direct user equipment based on the first pilot signal received from the direct user equipment. Then, based on the obtained channel estimation results, the direct user equipment is grouped and filtered, and the filtered direct user equipment is designated as reflecting user equipment. The second pilot signal is received based on the first user group, thus avoiding the influence of the first user group on the reflecting user equipment and user equipment within the second user group, and improving the accuracy of channel estimation for the reflecting user equipment.

[0128] Optionally, the first user group includes: the direct user equipment with a signal-to-noise ratio higher than a preset value;

[0129] The second user group refers to the user equipment other than the first user group among the direct user equipment.

[0130] In one embodiment of the present invention, grouping the direct user equipment according to the channel estimation result can be understood as grouping according to the signal-to-noise ratio of the direct user equipment.

[0131] Optionally, the step of performing channel estimation on the channel corresponding to the direct user equipment based on the first pilot signals transmitted by multiple direct user equipments to obtain the channel estimation result includes:

[0132] Based on the first pilot signal, channel estimation is performed on the channel corresponding to the direct user equipment to obtain a channel estimation result including signal-to-noise ratio and channel vector.

[0133] Optionally, the step of performing channel estimation on the channel corresponding to the direct user equipment based on the first pilot signal to obtain a channel estimation result including signal-to-noise ratio and channel vector includes:

[0134] Based on the first pilot signal, the least squares (LS) method is used to perform channel estimation on the channel corresponding to the direct user equipment, and the channel estimation result including the signal-to-noise ratio and the channel vector is obtained.

[0135] Optionally, the step of grouping the direct user equipment into at least one first user group and a second user group based on the channel estimation result includes:

[0136] Based on the singular value decomposition (SVD) of the channel vector or the orthogonal QR decomposition of the channel vector, the direct user equipment is grouped to obtain at least one first user group and one second user group.

[0137] In one embodiment of the present invention, the method for grouping the access user equipment includes two types: a grouping scheme based on ZF receiver (a grouping scheme based on singular value decomposition of the channel vector by SVD) and a grouping scheme based on QR reception (a grouping scheme based on orthogonal QR decomposition of the channel vector).

[0138] It should be noted that when high complexity is required or user equipment is required to decode separately, the packet scheme based on ZF reception should be selected; if there are requirements on the decoding order of user equipment and error propagation is not considered, the user packet scheme based on QR reception should be selected.

[0139] The channel estimation method of this invention, through two different user equipment grouping schemes, can adapt to different user equipment needs. By grouping the direct user equipment, the number of direct user equipment is reduced, and the accuracy of channel estimation for reflecting users is improved.

[0140] Optionally, the step of grouping the direct user equipment based on the singular value decomposition (SVD) of the channel vector to obtain at least one first user group and one second user group includes:

[0141] The channel vectors are decomposed using Singular Value Decomposition (SVD) to obtain the singular values ​​of each channel vector.

[0142] The direct user equipment corresponding to the channel vector with the largest singular value is designated as the first user equipment in the first user group;

[0143] Singular Value Decomposition (SVD) is performed on the channel matrix to determine other users within the first user group;

[0144] The user equipment in the direct user equipment, excluding the first user group, is divided into the second user group;

[0145] The channel matrix is ​​generated based on the channel vectors of the third user equipment and the fourth user equipment. The third user equipment refers to all the direct user equipment within the first user group, and the fourth user equipment refers to the direct user equipment outside the first user group.

[0146] The third user equipment refers to all the direct user equipment within the first user group. This can be understood as: the third user equipment refers to all the direct user equipment within the first user group at the current moment; for example: at the current moment, if there is only one direct user equipment within the first user group, then the third user equipment is the first user equipment; if there are multiple direct user equipment within the first user group, then the third user equipment is the first user equipment and the other users within the first user group.

[0147] Optionally, the step of performing singular value decomposition (SVD) on the channel matrix to determine other users within the first user group includes:

[0148] The target user device is selected as another user in the first user group by the user grouping criterion of maximizing the minimum singular value;

[0149] Repeat the selection of the target user equipment until the number of user equipment in the first user group reaches a preset threshold.

[0150] The user grouping criterion for maximizing the minimum singular value is as follows:

[0151] The channel vectors of the third user equipment and the fourth user equipment are combined to obtain multiple channel matrices.

[0152] Perform singular value decomposition (SVD) on the channel matrix to determine the minimum singular value of each channel matrix;

[0153] The target user equipment corresponding to the channel matrix with the largest minimum singular value is assigned to the first user group.

[0154] It should be noted that the preset threshold can be understood as an upper limit for users in the first user group. The preset threshold is set manually, or the preset threshold is determined based on the signal-to-noise ratio of the channel corresponding to the direct user equipment.

[0155] In one embodiment of the present invention, if there is only one first user group, the preset threshold is determined based on the signal-to-noise ratio of the channel corresponding to the direct user equipment; if there are multiple first user groups, the preset threshold of each first user group is set manually, and the sum of the preset thresholds of all first user groups is determined based on the signal-to-noise ratio of the channel corresponding to the direct user equipment.

[0156] Optionally, the step of grouping the direct user equipment based on the orthogonal QR decomposition of the channel vector to obtain at least one first user group and one second user group includes:

[0157] Calculate the norm of the channel vector, and take the direct user equipment corresponding to the channel vector with the largest norm as the first user equipment in the first user group;

[0158] Perform orthogonal QR decomposition on the channel matrix to determine other users within the first user group;

[0159] The user equipment in the direct user equipment, excluding the first user group, is divided into the second user group;

[0160] The channel matrix is ​​generated based on the channel vectors of the third user equipment and the fourth user equipment. The third user equipment refers to all the direct user equipment within the first user group, and the fourth user equipment refers to the direct user equipment outside the first user group.

[0161] Optionally, the step of performing orthogonal QR decomposition on the channel matrix to determine other users within the first user group includes:

[0162] The target user equipment is selected as other users in the first user group based on the target grouping criteria.

[0163] Repeatedly select the target user equipment until the number of users in the first user group reaches a preset threshold.

[0164] The target grouping criteria are as follows:

[0165] Calculate the orthogonal vector between the channel vector of the third user equipment and the channel vector of the fourth user equipment to obtain multiple target orthogonal vectors;

[0166] Calculate the norm of each target orthogonal vector, and assign the target user equipment corresponding to the target orthogonal vector with the largest norm to the first user group.

[0167] In one embodiment of the present invention, the preset threshold is determined based on the signal-to-noise ratio of the channel corresponding to the direct user equipment, or the preset threshold is set manually.

[0168] Optionally, the step of receiving the second pilot signal transmitted by the direct user equipment in the second user group based on the first user group includes:

[0169] The first channel matrix is ​​determined based on the channel vectors of the direct user equipment in the first user group;

[0170] Based on the first channel matrix, determine the null space corresponding to the first user group;

[0171] The second pilot signal is received in the null space.

[0172] like Figure 2 The diagram shows a logical schematic of a channel estimation method according to an embodiment of the present invention:

[0173] After a user equipment establishes a connection with a base station, the base station can identify the type of the user equipment (whether it is a direct user equipment or a reflective user equipment).

[0174] The base station receives a first pilot signal sent by the direct user equipment and performs channel estimation on the channel corresponding to the direct user equipment based on the first pilot signal to obtain the channel estimation result.

[0175] Based on the channel vector of the direct user equipment in the channel estimation result, the direct user equipment is grouped into a direct connection group and a reflection group;

[0176] The null space of the direct-connect group is determined by the channel vectors of the direct user equipment in the direct-connect group;

[0177] Receive second pilot signals transmitted by the direct user equipment and the reflected user equipment in the reflection group in the null space;

[0178] Channel estimation is performed on the channels corresponding to the direct user equipment and the reflective user equipment in the reflection group based on the second pilot signal;

[0179] It receives transmission signals sent by all user equipment and communicates with the user equipment.

[0180] like Figure 3 As shown, the user equipment grouping scheme based on ZF:

[0181] (1) Perform SVD decomposition on the channel vectors of all ungrouped direct user equipment (DMA) and select the DMA with the largest singular value as the first DMA in the group, i.e.:

[0182] u1 * =argmax u∈U λ u ;

[0183] In the formula, U is the set of ungrouped direct user equipment, and λ u Let u1 represent the singular values ​​of the channel vector of user u. * The first user device selected;

[0184] (2) Select users from the ungrouped direct user equipment and combine them with the grouped direct user equipment, and combine their channel vectors into a channel matrix. Perform SVD decomposition on the obtained channel matrix to obtain the singular value matrix of the channel matrix, whose diagonal elements are its singular values. Find the minimum singular value and use the following user grouping criterion that maximizes the minimum singular value:

[0185]

[0186] The direct user equipment to be allocated is compared and placed into a group, where λ is the direct user equipment to be allocated. u U represents the singular values ​​of the channel matrix. k * This refers to the kth user equipment selected.

[0187] (3) Repeat step (2) until the number of grouped user equipment reaches L. max ;

[0188] (4) The remaining direct user equipment is treated as reflective user equipment because the signal-to-noise ratio of the direct link after projection is small. It uses intelligent reflective surface to reflect and communicate with the base station. At this point, the user equipment grouping is completed.

[0189] like Figure 4 As shown, the user equipment grouping scheme based on QR is as follows:

[0190] (1) Select the first user equipment based on the norm of the channel vectors of all ungrouped direct user equipment, let A1 = h u By calculating the norm of A1 and selecting the direct user equipment with the largest norm, this user is designated as the first user equipment.

[0191]

[0192] Where h u Let u1 be the channel vector of user u. * Indicates the first selected direct user equipment;

[0193] (2) Select any user equipment u from the ungrouped users, and calculate the vector orthogonal to the channel vector of the grouped user equipment using the following formula:

[0194]

[0195] Then, by comparing the norms of the resulting vectors, the k-th user device is selected:

[0196]

[0197] Where L represents the number of grouped direct user equipment, u k * This indicates the k-th selected direct user equipment;

[0198] (3) Repeat step (2) until the number of grouped direct user devices reaches the maximum number of users L. max ;

[0199] (4) Since the signal-to-noise ratio of the direct link after projection is low, the remaining users are treated as reflective user equipment and communicate with the base station by using intelligent reflective surfaces. At this point, the user equipment grouping is completed.

[0200] like Figure 5 As shown, a channel estimation device 500 according to an embodiment of the present invention includes:

[0201] The first processing module 501 is used to perform channel estimation on the channel corresponding to the direct user equipment based on the first pilot signal sent by multiple direct user equipments, and obtain the channel estimation result. The direct user equipment is a user equipment that has a direct link with the base station.

[0202] The grouping module 502 is used to group the direct user equipment according to the channel estimation result to obtain at least one first user group and one second user group.

[0203] The receiving module 503 is configured to receive a second pilot signal sent by a target reflecting user equipment based on the first user group, wherein the target reflecting user equipment includes reflecting users and direct user equipment within the second user group;

[0204] The second processing module 504 is used to perform channel estimation on the channel corresponding to the target reflecting user equipment based on the second pilot signal.

[0205] The channel estimation apparatus of this invention performs channel estimation on the channel corresponding to the direct user equipment based on the first pilot signal received from the direct user equipment. Then, based on the obtained channel estimation results, it groups and filters the direct user equipment, designating the filtered direct user equipment as reflecting user equipment. The second pilot signal is received based on the first user group, thus avoiding the influence of the first user group on the reflecting user equipment and user equipment within the second user group, and improving the accuracy of channel estimation for the reflecting user equipment.

[0206] like Figure 6 As shown, a network device 600 according to an embodiment of the present invention includes a processor 610 and a transceiver 620, wherein,

[0207] The processor is used to perform channel estimation on the channel corresponding to the direct user equipment based on the first pilot signal sent by multiple direct user equipments, and obtain the channel estimation result. The direct user equipment is a user equipment that has a direct link with the base station.

[0208] Based on the channel estimation results, the direct user equipment is grouped to obtain at least one first user group and one second user group;

[0209] The transceiver is used to receive a second pilot signal transmitted by a target reflecting user equipment based on the first user group, wherein the target reflecting user equipment includes reflecting users and direct user equipment within the second user group;

[0210] The processor is further configured to perform channel estimation for the channel corresponding to the target reflecting user equipment based on the second pilot signal.

[0211] The network device in this embodiment of the invention performs channel estimation on the channel corresponding to the direct user equipment based on the first pilot signal received from the direct user equipment. Then, it groups and filters the direct user equipment based on the obtained channel estimation results, and treats the filtered direct user equipment as reflecting user equipment. The second pilot signal is received based on the first user group, which avoids the influence of the first user group on the reflecting user equipment and the user equipment in the second user group, and improves the accuracy of channel estimation for the reflecting user equipment.

[0212] Another embodiment of the present invention provides a terminal device, such as... Figure 7 As shown, it includes a transceiver 710, a processor 700, a memory 720, and a program or instructions stored in the memory 720 and executable on the processor 700; when the processor 700 executes the program or instructions, it implements the above-mentioned channel estimation method.

[0213] The transceiver 710 is used to receive and send data under the control of the processor 700.

[0214] Among them, Figure 7In this context, the bus architecture can include any number of interconnected buses and bridges, specifically linking various circuits of one or more processors represented by processor 700 and memory represented by memory 720 together. The bus architecture can also link various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further herein. The bus interface provides an interface. The transceiver 710 can be multiple elements, including transmitters and receivers, providing a unit for communicating with various other devices over a transmission medium. For different user equipment, the user interface 730 can also be an interface capable of connecting external or internal devices, including but not limited to keypads, displays, speakers, microphones, joysticks, etc.

[0215] The processor 700 is responsible for managing the bus architecture and general processing, while the memory 720 can store the data used by the processor 700 during operation.

[0216] The terminal device in this embodiment of the invention performs channel estimation on the channel corresponding to the direct user equipment based on the first pilot signal received from the direct user equipment. Then, it groups and filters the direct user equipment based on the obtained channel estimation results, and treats the filtered direct user equipment as reflecting user equipment. The second pilot signal is received based on the first user group, which avoids the influence of the first user group on the reflecting user equipment and the user equipment in the second user group, and improves the accuracy of channel estimation for the reflecting user equipment.

[0217] An embodiment of the present invention provides a readable storage medium storing a program or instructions. When the program or instructions are executed by a processor, they implement the steps in the channel estimation method described above and achieve the same technical effect. To avoid repetition, further details are omitted here.

[0218] The processor mentioned above is the processor in the terminal device described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0219] It should be further noted that the terminals described in this specification include, but are not limited to, smartphones, tablets, etc., and many of the functional components described are referred to as modules in order to emphasize the independence of their implementation.

[0220] In this embodiment of the invention, the module can be implemented in software so that it can be executed by various types of processors. For example, an identified executable code module may include one or more physical or logical blocks of computer instructions, which may be constructed as objects, procedures, or functions. Nevertheless, the executable code of the identified module does not need to be physically located together, but may include different instructions stored in different bits, which, when logically combined, constitute the module and achieve the module's intended purpose.

[0221] In practice, an executable code module can be a single instruction or many instructions, and can even be distributed across multiple different code segments, different programs, and across multiple memory devices. Similarly, operational data can be identified within the module and can be implemented in any suitable form and organized within any suitable type of data structure. This operational data can be collected as a single dataset or distributed across different locations (including different storage devices), and can exist, at least in part, solely as electronic signals within the system or network.

[0222] When a module can be implemented using software, considering the current level of hardware technology, modules that can be implemented in software can be implemented using hardware circuits by those skilled in the art to achieve the corresponding functions, without considering cost. These hardware circuits include conventional very-large-scale integrated circuits (VLSI) or gate arrays, as well as existing semiconductors such as logic chips and transistors, or other discrete components. Modules can also be implemented using programmable hardware devices, such as field-programmable gate arrays, programmable array logic, and programmable logic devices.

[0223] The exemplary embodiments described above are with reference to the accompanying drawings. Many different forms and embodiments are feasible without departing from the spirit and teachings of the invention. Therefore, the invention should not be construed as limiting the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided to make the invention complete and convey the scope of the invention to those skilled in the art. In these drawings, component dimensions and relative dimensions may be exaggerated for clarity. The terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. As used herein, unless clearly indicated otherwise, the singular forms “a,” “an,” and “the” are intended to include all such forms. It will be further understood that the terms “comprising” and / or “including”, when used in this specification, indicate the presence of the stated features, integers, steps, operations, components, and / or elements, but do not exclude the presence or addition of one or more other features, integers, steps, operations, components, and / or groups thereof. Unless otherwise indicated, when stated, a range of values ​​includes the upper and lower limits of the range and any subranges in between.

[0224] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A channel estimation method, characterized in that, Applied to a base station, the method includes: Based on the first pilot signals sent by multiple direct user equipments, channel estimation is performed on the channel corresponding to the direct user equipment to obtain the channel estimation result. The direct user equipment is a user equipment that has a direct link with the base station. Based on the channel estimation results, the direct user equipment is grouped to obtain at least one first user group and one second user group; Based on the first user group receiving the second pilot signal sent by the target reflecting user equipment, the target reflecting user equipment includes the reflecting user and the direct user equipment in the second user group; Channel estimation is performed on the channel corresponding to the target reflecting user equipment based on the second pilot signal.

2. The channel estimation method according to claim 1, characterized in that, The first user group includes: the direct user equipment with a signal-to-noise ratio higher than a preset value; The second user group refers to the user equipment other than the first user group among the direct user equipment.

3. The channel estimation method according to claim 1 or 2, characterized in that, The step of performing channel estimation on the channel corresponding to the direct user equipment based on the first pilot signals transmitted by multiple direct user equipments to obtain the channel estimation result includes: Based on the first pilot signal, channel estimation is performed on the channel corresponding to the direct user equipment to obtain a channel estimation result including signal-to-noise ratio and channel vector.

4. The channel estimation method according to claim 3, characterized in that, The step of grouping the direct user equipment into at least one first user group and a second user group based on the channel estimation result includes: Based on the singular value decomposition (SVD) of the channel vector or the orthogonal QR decomposition of the channel vector, the direct user equipment is grouped to obtain at least one first user group and one second user group.

5. The channel estimation method according to claim 4, characterized in that, The process of grouping the direct user equipment based on the singular value decomposition (SVD) of the channel vector to obtain at least one first user group and one second user group includes: The channel vectors are decomposed using Singular Value Decomposition (SVD) to obtain the singular values ​​of each channel vector. The direct user equipment corresponding to the channel vector with the largest singular value is designated as the first user equipment in the first user group; Singular Value Decomposition (SVD) is performed on the channel matrix to determine other users within the first user group; The user equipment in the direct user equipment, excluding the first user group, is divided into the second user group; The channel matrix is ​​generated based on the channel vectors of the third user equipment and the fourth user equipment. The third user equipment refers to all the direct user equipment within the first user group, and the fourth user equipment refers to the direct user equipment outside the first user group.

6. The channel estimation method according to claim 5, characterized in that, The step of performing singular value decomposition (SVD) on the channel matrix to determine other users within the first user group includes: The target user device is selected as another user in the first user group by the user grouping criterion of maximizing the minimum singular value. Repeat the selection of the target user equipment until the number of user equipment in the first user group reaches a preset threshold. The user grouping criterion for maximizing the minimum singular value is as follows: The channel vectors of the third user equipment and the fourth user equipment are combined to obtain multiple channel matrices. Perform singular value decomposition (SVD) on the channel matrix to determine the minimum singular value of each channel matrix; The target user equipment corresponding to the channel matrix with the largest minimum singular value is assigned to the first user group.

7. The channel estimation method according to claim 4, characterized in that, The step of grouping the direct user equipment based on the orthogonal QR decomposition of the channel vector to obtain at least one first user group and one second user group includes: Calculate the norm of the channel vector, and take the direct user equipment corresponding to the channel vector with the largest norm as the first user equipment in the first user group; Perform orthogonal QR decomposition on the channel matrix to determine other users within the first user group; The user equipment in the direct user equipment, excluding the first user group, is divided into the second user group; The channel matrix is ​​generated based on the channel vectors of the third user equipment and the fourth user equipment. The third user equipment refers to all the direct user equipment within the first user group, and the fourth user equipment refers to the direct user equipment outside the first user group.

8. The channel estimation method according to claim 7, characterized in that, The step of performing orthogonal QR decomposition on the channel matrix to determine other users within the first user group includes: The target user equipment is selected as other users in the first user group based on the target grouping criteria. Repeatedly select the target user equipment until the number of users in the first user group reaches a preset threshold. The target grouping criteria are as follows: Calculate the orthogonal vector between the channel vector of the third user equipment and the channel vector of the fourth user equipment to obtain multiple target orthogonal vectors; Calculate the norm of each target orthogonal vector, and assign the target user equipment corresponding to the target orthogonal vector with the largest norm to the first user group.

9. The channel estimation method according to claim 1, characterized in that, The step of receiving the second pilot signal sent by the direct user equipment in the second user group based on the first user group includes: The first channel matrix is ​​determined based on the channel vectors of the direct user equipment in the first user group; Based on the first channel matrix, determine the null space corresponding to the first user group; The second pilot signal is received in the null space.

10. A channel estimation device, characterized in that, include: The first processing module is used to perform channel estimation on the channel corresponding to the direct user equipment based on the first pilot signal sent by multiple direct user equipments, and obtain the channel estimation result. The direct user equipment is a user equipment that has a direct link with the base station. The grouping module is used to group the direct user equipment according to the channel estimation results to obtain at least one first user group and one second user group. The receiving module is configured to receive a second pilot signal transmitted by a target reflecting user equipment based on the first user group, wherein the target reflecting user equipment includes reflecting users and direct user equipment within the second user group; The second processing module is used to perform channel estimation on the channel corresponding to the target reflecting user equipment based on the second pilot signal.

11. A network device, characterized in that, include: Transceiver and processor; The processor is used to perform channel estimation on the channel corresponding to the direct user equipment based on the first pilot signal sent by multiple direct user equipments, and obtain the channel estimation result. The direct user equipment is a user equipment that has a direct link with the base station. Based on the channel estimation results, the direct user equipment is grouped to obtain at least one first user group and one second user group; The transceiver is used to receive a second pilot signal transmitted by a target reflecting user equipment based on the first user group, wherein the target reflecting user equipment includes reflecting users and direct user equipment within the second user group; The processor is further configured to perform channel estimation for the channel corresponding to the target reflecting user equipment based on the second pilot signal.

12. A terminal device, comprising: A transceiver, a processor, a memory, and a program or instructions stored in the memory and executable on the processor; characterized in that, when the processor executes the program or instructions, it implements the channel estimation method as described in any one of claims 1-9.

13. A readable storage medium having a program or instructions stored thereon, characterized in that, When the program or instructions are executed by the processor, they implement the steps in the channel estimation method as described in any one of claims 1-9.

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