Flexible access cross-domain efficient anti-interference transmission method

Abstract

The application discloses a flexible access cross-domain efficient anti-interference transmission method, which comprises the following steps: dividing a communication transmission process into a training stage and a data transmission stage, and dividing the training stage into multiple mini-slots; in each mini-slot of the training stage: a base station in a cellular network firstly generates a group of flexible access vectors randomly, then constructs a useful signal space of a receiving signal space and broadcasts to all users in a cell where the base station is located; a user constructs an interference leakage matrix and calculates a user beamforming weight; an interference leakage value of the user is set, and the base station selects the user by using the interference leakage value; the spectral efficiency corresponding to each mini-slot is determined by a signal-to-interference-and-noise ratio of a receiving end and the user beamforming weight; in the data transmission stage: the base station determines a flexible access vector corresponding to a mini-slot with maximum spectral efficiency, and applies the flexible access vector to a communication process of a user selected by the interference leakage value.

Description

Technical Field

[0001] The present invention belongs to the field of communication technology, and in particular relates to a flexible access cross-domain efficient anti-interference transmission method. Background Art

[0002] Currently, utilizing effective interference management schemes to improve transmission performance has become a key technology in wireless networks. Traditional interference-resistant transmission schemes achieve interference cancellation by partitioning the signal space into an interference subspace and a null space within the interference subspace. Using directional access techniques, these schemes direct the interfering signal into the interference subspace and transmit the desired signal within the null space. For example, interference-resistant transmission schemes are applied to multi-cell interference multiple access channel networks, performing group-assisted interference alignment. However, these traditional schemes often require perfect channel state information (CSI) to calculate the directional access vector, resulting in high complexity. Summary of the Invention

[0003] The purpose of the present invention is to provide a cross-domain efficient anti-interference transmission method with flexible access, which jointly processes the weight of flexible access and user selection scheme to minimize interference and achieve efficient transmission.

[0004] In order to achieve the above tasks, the present invention adopts the following technical solutions:

[0005] A flexible access, cross-domain, efficient, and anti-interference transmission method, comprising:

[0006] The duration of a communication transmission process between a base station and a user in a cellular network is divided into a training phase and a data transmission phase, wherein the training phase is further divided into a plurality of mini-time slots;

[0007] During each mini-slot of the training phase:

[0008] The base station in the cellular network first randomly generates a set of flexible access vectors, then constructs a useful signal space of the received signal space based on the flexible access vectors and broadcasts it to all users in the cell where the base station is located;

[0009] Based on the channel matrix between the user and the base station and the useful signal space, the user constructs the interference leakage matrix and calculates the user beamforming weight;

[0010] The base station sets the user's interference leakage value, which it uses to select users. The spectrum efficiency corresponding to each mini-slot is determined by the signal-to-interference-and-noise ratio (SINR) at the receiver and the user's beamforming weight.

[0011] During the data transmission phase:

[0012] The base station determines a flexible access vector corresponding to a mini-time slot with maximum spectrum efficiency, and applies the flexible access vector to the communication process of users screened out by the interference leakage value.

[0013] Furthermore, the duration of a communication transmission process between a base station and a user in the cellular network is a time slot T , it is divided into training phase and data transmission phase in the ratio of 2:8. The training phase is divided into M The length is Mini-slots, where M Not less than 10, .

[0014] Furthermore, the flexible access vector is expressed as:

[0015]

[0016] And there are:

[0017]

[0018] in, Representative In the mini-slot, The first receiving antenna receives The vector of the BS of the cellular network, and satisfy , and Represent the flexible access coefficients The amplitude and phase of is the natural base, represents the imaginary unit, express dimensional complex space; , M is the total number of mini-slots, represents the number of receiving antennas arranged in the base station BS;

[0019] The useful signal space Expressed as:

[0020] .

[0021] Furthermore, based on the channel matrix between the user and the base station and the useful signal space, the user constructs an interference leakage matrix and calculates the user beamforming weight, including:

[0022] Interference leakage matrix Perform singular value decomposition SVD and get:

[0023]

[0024] in is the unitary matrix obtained by singular value decomposition, is the singular value matrix, , is the interference leakage matrix of singular values, It is obtained after singular value decomposition unit orthogonal column vectors, define , that is, get the The beamforming weights for each user.

[0025] Further, the Transmit beamforming weights for each user ,satisfy:

[0026]

[0027] in and , represents the square of the two-norm, Indicates the In the mini-slot users and Channel matrix between base stations; For the The interference leakage matrix of a user is expressed as:

[0028]

[0029] in , Representative The first base station The user and other base stations choose from 1 to The channel matrix between users, is the number of cellular networks, The number of transmit antennas deployed for the user, .

[0030] Furthermore, the user's interference leakage value Expressed as:

[0031]

[0032] in Represents the interference leakage matrix The minimum singular value obtained by performing singular value decomposition.

[0033] Furthermore, the base station uses the interference leakage value to select a user, specifically:

[0034] All the cells where the base station BS is located Each user feeds back the calculated interference leakage value to the BS, and the BS selects the user with the smallest interference leakage value. users.

[0035] Furthermore, determining the spectrum efficiency corresponding to each mini-time slot based on the signal-to-interference-and-noise ratio (SINR) at the receiving end and the user beamforming weight includes:

[0036] For the The base station in the cellular network receives the signal:

[0037]

[0038] The transmitted signal is , The power spectral density is Gaussian white noise; the transmitted signal and the received signal are data sent and received between the user and the base station for training during the training phase; For the users and The channel matrix between base stations, For the The transmit beamforming weights of each user;

[0039] After zero-forcing equalization, the signal-to-interference-and-noise ratio (SINR) at the receiving end is:

[0040]

[0041] in Representatives seek false rebellion, is the power spectral density of Gaussian white noise, represents the square of the two-norm, Represents the useful signal in the transmitted signal or received signal, Represents the interference signal in the transmitted or received signal, is the equivalent user channel, i.e. The first base station The transmission channel of the useful signal of each user, is the equivalent interference channel, i.e. The first base station The transmission channel of the interference signal of each user;

[0042] No. m The spectrum efficiency SE corresponding to each mini-time slot is:

[0043] .

[0044] A terminal device includes a processor, a memory, and a computer program stored in the memory; when the processor is executed by a computer, the flexible access cross-domain efficient anti-interference transmission method is implemented.

[0045] A computer-readable storage medium stores a computer program; when the computer program is executed by a processor, the flexible access cross-domain efficient anti-interference transmission method is implemented.

[0046] Compared with the prior art, the present invention has the following technical features:

[0047] Compared with the traditional anti-interference transmission system, the present invention achieves higher SE and lower interruption probability with lower computational complexity in the absence of perfect CSI and with a small number of candidate users, thereby realizing efficient cross-domain anti-interference transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 A cross-domain, efficient, and anti-interference network model diagram for flexible access;

[0049] Figure 2 This is a graph showing how system spectrum efficiency changes with signal-to-noise ratio under different numbers of users;

[0050] Figure 3 is the cumulative distribution function graph of the signal to interference and noise ratio;

[0051] Figure 4 is the probability density function diagram of the signal to interference and noise ratio;

[0052] Figure 5 This is a graph showing how the outage probability changes with the signal-to-noise ratio under different numbers of users;

[0053] Figure 6 The following is a comparison chart of the spectrum efficiency of the efficient anti-interference transmission scheme and the traditional anti-interference transmission scheme under different numbers of users. DETAILED DESCRIPTION

[0054] The present invention proposes a flexible access solution that does not require perfect CSI and complex channel estimation, that is, it uses randomly generated flexible access weights instead of the directional access vector that needs to be calculated. In order to solve the problem of reduced system performance when the number of users is small, the cross-domain idea is introduced to improve the spectrum efficiency (SE) by selecting the most appropriate weights in different networks, thereby compensating for the performance of the scheme when the number of users is insufficient. In addition, the cumulative distribution function (CDF) and probability density function (PDF) of the signal-to-interference-plus-noise ratio (SINR) of the system under the flexible access cross-domain efficient anti-interference transmission scheme are derived. At the same time, closed expressions for the interruption probability and symbol error rate are given based on the CDF and PDF.

[0055] The present invention proposes a flexible access cross-domain efficient anti-interference transmission method, which jointly processes the flexible access weight and service users with the goal of maximizing SE, thereby improving the system SE and reducing the system interruption probability by minimizing interference.

[0056] Based on wireless communication principles, the present invention targets uplink multi-user cellular network communications and uses flexible access weights to replace the directional access vectors that need to be calculated in traditional communication networks (the transmitter preprocesses the transmitted signal to eliminate channel effects, thereby increasing the complexity and overhead of the receiver's received signal), achieving efficient communication.

[0057] See also Figure 1 The network targeted by the present invention includes A cellular network, in which a base station BS is deployed at the center of each cell, and Root receiving antenna, cellular networks have users, each user deploys Root transmitting antenna; in one transmission process, select It is assumed that the signal interference within the cell is ignored.

[0058] The duration of a communication transmission process between a base station and a user in a cellular network is The time slot is divided into a training phase and a data transmission phase, where the training phase occupies 20% of the entire time slot and the data transmission phase occupies 80% of the entire time slot, and the training phase is divided into M (Not less than 10) lengths The mini-time slot is used to generate and estimate the random access vector; A cellular network is used as an example for explanation.

[0059] In step 1, the existing technology requires a large amount of calculation in the data training phase to obtain a directional access vector. Unlike the traditional method, this solution proposes a randomly generated flexible access vector to reduce the complexity of the algorithm.

[0060] No. The BS of a cellular network randomly generates a set of flexible access vectors:

[0061]

[0062] The subscript Representative Mini time slots, , the coefficient of flexible access Representative In the mini-slot, The first receiving antenna receives The vector of the BS of the cellular network, and satisfy , represents the power of the flexible access coefficient, and Represent the flexible access coefficients The amplitude and phase of is the natural base, represents the imaginary unit, express dimensional complex space.

[0063] In order to ensure constant power, assume:

[0064]

[0065] The base station divides the received signal space, consisting of the received signals fed back by each user to the base station, into an interference subspace and a null space within the interference subspace. This division into an interference space and a useful space is a measure to reduce interference. By preprocessing the beamforming vectors, the useful signal is maximized to propagate within the useful space and the interference signal within the interference channel, thereby reducing the impact of the interference signal and improving the system's spectral efficiency (SE).

[0066] The null space of the interference subspace is used to transmit useful signals, also called useful signal space, and the interference subspace and useful signal space Respectively expressed as:

[0067]

[0068]

[0069] BS broadcasts the interference subspace to all users and useful signal space .

[0070] Step 2, Build For the users and The channel matrix between base stations:

[0071]

[0072] in Indicates the In the mini-slot users and The first base station The channel vector between the root receiving antennas; in this scheme, the right subscript of the matrix represents the matrix dimension, such as the matrix dimension of the above formula is , the same below.

[0073] The user constructs the interference leakage matrix and calculates the user beamforming weight; The interference leakage matrix of a user is defined as:

[0074]

[0075] in Expressed as:

[0076]

[0077] in Representative The first base station The user and other base stations choose from 1 to The channel matrix between users (users with the smallest interference leakage value).

[0078] No. Transmit beamforming weights for each user ,satisfy:

[0079]

[0080] in Useful signal space , and , represents the square of the 2-norm.

[0081] For design , and realize equivalent interference channel The null space of the interference subspace There is no correlation between them, considering the interference leakage matrix Perform singular value decomposition (SVD) and get:

[0082]

[0083] in is the unitary matrix obtained by singular value decomposition, is the singular value matrix, , is the interference leakage matrix The singular values ​​of is the unit orthogonal column vector obtained after singular value decomposition, since The smallest singular value corresponding to the decomposition, and the singular value can reflect the correlation of the space to a certain extent, so the definition , that is, get the The beamforming weights for each user.

[0084] Step 3: Set the square of the minimum singular value obtained by SVD as the user's interference leakage value , expressed as:

[0085]

[0086] Step 4: Interference leakage value As an indicator for BS to select users; all the cells where the BS is located Each user feeds back the calculated interference leakage value to the BS; the BS selects the user with the smallest interference leakage value. users; at this time, the BS is subject to minimal interference from users in other cells, thus achieving efficient transmission.

[0087] For the The base station in the cellular network receives the signal:

[0088]

[0089] The transmitted signal is , The power spectral density is Gaussian white noise; the transmitted signal and the received signal are data sent and received between the user and the base station for training during the training phase.

[0090] After zero-forcing equalization, the signal-to-interference-and-noise ratio (SINR) at the receiving end is:

[0091]

[0092] in Representatives seek false rebellion, is the power spectral density of Gaussian white noise, represents the square of the two-norm, Represents the useful signal (the signal expected to be received) in the transmitted signal or received signal. Represents the interference signal in the transmitted or received signal, U represents useful, I represents interference, and equ represents equivalent. is the equivalent user channel, i.e. The first base station The transmission channel of the useful signal of each user, is the equivalent interference channel, i.e. The first base station The transmission channel of the interference signal of each user.

[0093] No. m The spectrum efficiency SE corresponding to each mini-time slot is:

[0094]

[0095] Step 5, BS compares all M The spectral efficiency SE is determined in the mini-time slot; then, the BS selects the mini-time slot with the largest SE; in the data transmission phase, the BS uses the flexible access vector in the mini-time slot for the one with the smallest interference leakage value selected in step 4. The communication process of a user.

[0096] Therefore, the spectral efficiency of the entire system can be expressed as:

[0097]

[0098] in represents the expectation, and the spectral efficiency of the entire system is represented by the ergodic situation obtained after the expectation is obtained; see Figure 6 As shown in the example, compared with the traditional solution, the system spectrum efficiency of this solution is significantly improved under different numbers of users.

[0099] Interruption probability and symbol error rate are very important indicators for measuring communication systems. , Taking as an example, the statistical characteristics of SINR are derived and analyzed.

[0100] At this time, SINR is expressed as:

[0101]

[0102] in is the transmit power, is the noise power at the receiving end.

[0103] Considering the numerator of SINR, due to and is a unit vector and is independent of , and The mathematical statistical properties are consistent.

[0104] Assumptions Elements of obedience Rayleigh distribution, then is an exponential variable. To simplify the mathematics, let:

[0105]

[0106] but The CDF and PDF of are:

[0107]

[0108]

[0109] For the denominator of SINR, since and They are similar and can be considered to follow the same distribution. Rewritten as:

[0110]

[0111] right Perform SVD decomposition and get:

[0112]

[0113] According to the above formula, It can be written as:

[0114]

[0115] in Represents a unitary matrix The elements of the first row and second column of express The minimum singular value of . Therefore, we have:

[0116]

[0117] Similarly, we have:

[0118]

[0119] Use the average value to approximate ,have to:

[0120]

[0121] definition ,in is a second-order Wishart matrix, so the interference leakage matrix The mathematical statistical characteristics of the minimum singular value of are:

[0122]

[0123] According to the knowledge related to order statistics, since there are Users waiting for service, The probability density of is:

[0124]

[0125] According to the isotropy between users, , and have similar mathematical statistical characteristics. Therefore, we can get:

[0126]

[0127] The PDF is:

[0128]

[0129] set up ,but

[0130]

[0131] therefore, The CDF and PDF of are expressed as:

[0132]

[0133] Assume that the threshold of the outage probability is given by If , the interruption probability is expressed as:

[0134]

[0135] The symbol error rate is expressed as:

[0136]

[0137] The binary phase shift keying (BPSK) modulation is used, which means Gaussian Q function.

[0138] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A flexible access cross-domain efficient anti-interference transmission method, characterized in that: include: The duration of a communication transmission process between a base station and a user in a cellular network is divided into a training phase and a data transmission phase, wherein the training phase is further divided into a plurality of mini-time slots; During each mini-slot of the training phase: A base station in a cellular network first randomly generates a set of flexible access vectors, then constructs a useful signal space of the received signal space based on the flexible access vectors and broadcasts it to all users in the cell where the base station is located. The flexible access vectors are expressed as: And there are: in, Representative In the mini-slot, The first receiving antenna receives The vector of the BS of the cellular network, and satisfy , and Represent the flexible access coefficients The amplitude and phase of is the natural base, represents the imaginary unit, express dimensional complex space; , M is the total number of mini-slots, represents the number of receiving antennas arranged in the base station BS; The useful signal space Expressed as: ； Based on the channel matrix between the user and the base station and the useful signal space, the user constructs the interference leakage matrix and calculates the user beamforming weights, including: Interference leakage matrix Perform singular value decomposition SVD and get: in is the unitary matrix obtained by singular value decomposition, is the singular value matrix, , is the interference leakage matrix of singular values, It is obtained after singular value decomposition unit orthogonal column vectors, define , that is, get the Beamforming weights for each user; Set the user's interference leakage value, and the base station uses the interference leakage value to select users; determine the spectrum efficiency corresponding to each mini-time slot through the signal-to-interference-noise ratio at the receiving end and the user's beamforming weight; the user's interference leakage value Expressed as: in Represents the interference leakage matrix The minimum singular value obtained by performing singular value decomposition; the base station uses the interference leakage value to select the user, specifically: All the cells where the base station BS is located Each user feeds back the calculated interference leakage value to the BS, and the BS selects the user with the smallest interference leakage value. users; During the data transmission phase: The base station determines a flexible access vector corresponding to a mini-time slot with maximum spectrum efficiency, and applies the flexible access vector to the communication process of users screened out by the interference leakage value.

2. The cross-domain efficient anti-interference transmission method with flexible access according to claim 1 is characterized in that The duration of a communication transmission process between the base station and the user in the cellular network is a time slot T , it is divided into training phase and data transmission phase in the ratio of 2:

8. The training phase is divided into M The length is Mini-slots, where M Not less than 10, .

3. The cross-domain efficient anti-interference transmission method with flexible access according to claim 1 is characterized in that No. Transmit beamforming weights for each user ,satisfy: in and , represents the square of the two-norm, Indicates the In the mini-slot users and Channel matrix between base stations; For the The interference leakage matrix of a user is expressed as: in , Representative The first base station The user and other base stations choose from 1 to The channel matrix between users, is the number of cellular networks, The number of transmit antennas deployed for the user, .

4. The cross-domain efficient anti-interference transmission method with flexible access according to claim 1 is characterized in that The determining of the spectrum efficiency corresponding to each mini-time slot by using the signal-to-interference-and-noise ratio (SINR) of the receiving end and the user beamforming weight includes: For the The base station in the cellular network receives the signal: The transmitted signal is , The power spectral density is Gaussian white noise; the transmitted signal and the received signal are data sent and received between the user and the base station for training during the training phase; For the users and The channel matrix between base stations, For the The transmit beamforming weights of each user; After zero-forcing equalization, the signal-to-interference-and-noise ratio (SINR) at the receiving end is: in Representatives seek false rebellion, is the power spectral density of Gaussian white noise, represents the square of the two-norm, Represents the useful signal in the transmitted signal or received signal, Represents the interference signal in the transmitted or received signal, is the equivalent user channel, i.e. The first base station The transmission channel of the useful signal of each user, is the equivalent interference channel, i.e. The first base station The transmission channel of the interference signal of each user; No. m The spectrum efficiency SE corresponding to each mini-time slot is: 。 5. A terminal device comprising a processor, a memory, and a computer program stored in the memory; when the processor is executed by a computer, it implements the flexible access cross-domain efficient anti-interference transmission method according to any one of claims 1-4.

6. A computer-readable storage medium storing a computer program; when the computer program is executed by a processor, the cross-domain efficient and anti-interference transmission method with flexible access according to any one of claims 1 to 4 is implemented.

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