Receiver control method, system, device and terminal in sudden interference scenario

Abstract

The present invention belongs to the field of information and communication technologies and discloses a receiver control method, system, device, and terminal for use in burst interference scenarios. A small number of silent carriers are provided to collect information about burst interference. The received signals on the silent carriers are used to estimate the covariance matrix of the burst interference and use it for demodulation. An MMSE-IRC estimation module A and a soft demodulation noise reduction module B are designed based on the constellation information of the target symbol. In MMSE-IRC estimation module A, an MMSE-IRC estimation of the target signal is performed, and in module B, the constellation information is used to reduce the noise of the input estimate. Alternate iterations are performed between the two modules until convergence. When a large number of symbols in a data frame are subject to burst interference, the carrier muting scheme proposed in the present invention can effectively suppress interference. Under high-order modulation, the performance gain is significant, and the difference from the interference-free situation can be controlled to within 1.5 dB, effectively eliminating burst interference and significantly improving receiver demodulation performance.

Description

Technical Field

[0001] The present invention belongs to the field of information and communication technology, and in particular relates to a receiver control method, system, device and terminal in a sudden interference scenario. Background Art

[0002] Currently, 5.5G uplink ultra-wideband (UWB) scenarios require the use of refarming F, A, and E bands for uplink data transmission. However, these bands are subject to sudden interference, such as atmospheric waveguide interference and inter-standard interference, which severely impacts communication system performance. This sudden interference originates from outside the communication system and has relatively high energy intensity. Within an OFDM frame, the interference sometimes only affects some data symbols, while the pilot symbols remain unaffected, making it impossible to measure the interference using the pilot symbols.

[0003] For general interference suppression algorithm frameworks, when interference occurs, a cross term between the interference and the target signal appears, which increases with the increase in target signal energy. The accuracy of existing interference covariance measurement methods is limited by this cross term, especially at high-order modulation, where detection performance deteriorates sharply compared to the absence of the cross term. On the other hand, message passing algorithms within a Bayesian framework can use prior information about the target signal or interference to achieve noise reduction, gradually eliminating some interference through iteration between modules. However, such iterative algorithms often lack prior information about the interference or have weak prior information, resulting in the need for many iterations to achieve good performance. This is especially true when interference occurs on multiple data symbols, resulting in high demodulation complexity for the entire data frame and low overall algorithm efficiency. Furthermore, for algorithms that use the target signal constellation diagram for noise reduction, the constellation diagram's noise reduction capability decreases with increasing modulation order, which not only increases the number of algorithm iterations but also severely limits algorithm performance.

[0004] In burst interference scenarios, the interference on some data symbols originates from different sources than the interference on pilot symbols. Traditional interference suppression frameworks struggle to obtain a more accurate interference covariance matrix. Algorithms based on message passing frameworks are limited by the strength of prior information and often require multiple iterations to converge to a good result. Therefore, a new receiver control method for burst interference scenarios is urgently needed.

[0005] Through the above analysis, the problems and defects of the existing technology are as follows:

[0006] (1) For the general interference suppression algorithm framework, when interference occurs, a cross term between the interference and the target signal will appear, and it will increase with the increase of the target signal energy. The accuracy of the existing interference covariance measurement method is limited by this cross term, especially under high-order modulation, the detection performance deteriorates sharply compared with the absence of the cross term.

[0007] (2) The existing message passing algorithms under the Bayesian framework lack prior information about interference or the prior information is weak, resulting in the need for many iterations to achieve good performance. In particular, when interference occurs on multiple data symbols, the demodulation complexity of the entire data frame is high, and the overall efficiency of the algorithm is low.

[0008] (3) For algorithms that use the target signal constellation information to reduce noise, the constellation noise reduction capability decreases with the increase of the modulation order, which not only increases the number of algorithm iterations but also severely limits the algorithm performance. Summary of the Invention

[0009] To address the problem that existing receivers lack prior information on burst interference, the present invention provides a receiver control method, system, device and terminal in a burst interference scenario, and in particular relates to a target signal estimation and demodulation method, system, medium, device and terminal in a burst interference scenario based on carrier muting.

[0010] The present invention is implemented as follows: a receiver control method in a burst interference scenario, the receiver control method in the burst interference scenario comprising: setting a small number of silent carriers for collecting information on the burst interference, using the received signal on the silent carrier to estimate the covariance matrix of the burst interference and use it for demodulation; designing an MMSE-IRC estimation module A and a soft demodulation noise reduction module B based on the constellation diagram information of the target symbol; performing MMSE-IRC estimation on the target signal in the MMSE-IRC estimation module A, and using the constellation diagram information in the module B to reduce the noise of the input estimated value; and alternating iterations between the two modules until convergence.

[0011] Furthermore, the receiver control method in the sudden interference scenario includes the following steps:

[0012] Step 1: System modeling: There are T i OFDM data symbols are affected by burst interference. When the interference does not occur on the pilot symbol and the location of the interference is known, the system frequency domain bandwidth is K = 12N. RB subcarriers, N RB is the number of resource blocks;

[0013] Step 2, block model: Considering the correlation of channels on adjacent carriers, the adjacent R RBs are regarded as a sub-block, and the system is divided into Q = N RB / R sub-blocks; at the same time, T i The same sub-blocks of OFDM symbols are concatenated, and the dimension of each sub-block is N r ×M, where M=KT i / Q; The positive effect of the block model is that the channel coefficients on adjacent subcarriers are approximately flat, and the average value (finite sample average) of the interference covariance matrix on each carrier can well approximate the mean value (mathematical expectation) of the interference covariance matrix;

[0014] Step 3: Carrier muting: P silent carriers are now set in each sub-block. The positions of the silent carriers are evenly distributed in M ​​columns within the sub-block. In the system, one carrier does not transmit the target signal for every M / P sub-carriers. The received signal on the silent carriers and the received signal on the normal carriers are determined. The positive effect of carrier muting is that it can collect a small number of relatively accurate interference samples for the receiver to extract interference characteristics.

[0015] Step 4: Initialize receiver parameters: in represents the prior information of the target symbol S in module A, is the prior value The prior variance is N s ×1 vector, the target symbol estimates of different users in the same sub-block correspond to different variances. The variance of the target symbol is in vector form because the channel gains of different users vary to a certain extent. The vector form variance can more accurately describe this phenomenon, making the variance calculation of the estimated value more accurate.

[0016] Step 5: Construct MMSE-IRC estimation module A: Use the received signal on the silent carrier to estimate the interference covariance matrix, and perform MMSE-IRC estimation based on the estimated covariance matrix. Module A estimates the interference covariance matrix based on the interference signal collected on the silent carrier, thereby suppressing the interference and preliminarily estimating the target symbol.

[0017] Step 6: Calculate the extrinsic information of module A: Take the average of the posterior variances of different users in the sub-block to calculate the extrinsic information of module A, and then input the extrinsic information of the target symbol into module B. The positive effect of the extrinsic information calculation is to decouple the input noise and output noise of module A.

[0018] Step 7: Construct soft demodulation noise reduction module B: In module B, use the constellation diagram information of the target symbol to estimate the value Noise reduction, n rows and m′ columns elements are The variance is Module B reduces the error of the estimated value input to module B (i.e., the external information output by module A) through the constellation diagram information, making the estimated value more accurate than the input;

[0019] Step 8: Calculate the extrinsic information of module B: average the posterior variances of different users within a sub-block, and then return the extrinsic information mean and variance of module B to module A. The purpose of averaging the posterior variances is to reduce the calculation error by using a larger number of samples.

[0020] Step nine: If the algorithm converges or reaches the preset maximum number of iterations, the algorithm ends; otherwise, the algorithm proceeds to step five to perform MMSE-IRC estimation on each column in the sub-block to determine the posterior mean and variance of the target symbol.

[0021] Furthermore, in step 1, when the number of receiving antennas at the base station is N r , the target signal stream number is N s , the number of interference signal streams is N i , the base station received signal on the kth subcarrier of the tth data symbol is expressed as:

[0022]

[0023] in, is the target user channel, To interfere with user channels, is the target signal, is the interference signal, is white noise.

[0024] In step 2, the received signal of the mth column in the qth sub-block is:

[0025] y q，m =H q，m s q，m +H I，q，m s I，q，m +n q，m

[0026] =H q，m s q，m +l q，m +n q，m

[0027] Wherein, the subscripts q and m correspond to the qK / Q+mod(m-1, K / Q)+1th carrier on the ceil(mQ / K)th OFDM data symbol affected by the burst interference, ceil(x) means rounding up x, mod(x, y) means the value of x modulo y, l q，m =H I，q，m s I，q，m Indicates an interference signal.

[0028] Furthermore, in step 3, the received signal on the silent carrier is:

[0029] l mute，q，p =l q，p +nq，p ,

[0030] The subscript p corresponds to the (p-1)M / P+1th column signal in the sub-block. The received signal on the silent carrier is spliced ​​into a matrix form.

[0031] The received signal on a normal carrier is:

[0032] y q，m′ =H q，m′ s q，m′ +l q，m′ +n q，m′ ,

[0033] Where m′≠p corresponds to the subscript of the non-silent carrier. The received signal on the normal carrier is spliced ​​into a matrix form. The target symbol is represented as a matrix The sub-block subscript q is omitted in subsequent steps.

[0034] In step 4 and subsequent steps, the abbreviation "pri" of the superscript "prior" represents prior information, the abbreviation "post" of the superscript "posterior" represents posterior information, and the abbreviation "ext" of the superscript "extrinsic" represents extrinsic information. Different superscripts for the same symbol are used to distinguish the information category. The subscripts A and B respectively indicate the modules A and B to which the corresponding symbols belong.

[0035] Furthermore, the MMSE-IRC estimation module A in step 5 estimates the covariance matrix of interference using the received signal on the silent carrier, and performs MMSE-IRC estimation based on the estimated covariance matrix, including:

[0036] (1) Using L mute The estimated interference covariance matrix is:

[0037]

[0038] Where P is the number of silent carriers in a single sub-block. To solve the rank deficiency problem when the number of estimated samples is smaller than the dimension of the covariance matrix, the noise floor is loaded as:

[0039]

[0040] in, is the background white noise energy intensity, and I is the unit matrix.

[0041] (2) Perform MMSE-IRC estimation on each column in the sub-block, and the posterior mean and variance of the target symbol are:

[0042]

[0043]

[0044] in, It means that the diagonal matrix is ​​formed with vector x as the diagonal element. And diag(X) means taking the diagonal elements of matrix X as column vectors.

[0045] The calculation of external information of module A in step 6 includes:

[0046] Take the average of the posterior variance of different users in the sub-block:

[0047]

[0048] The formula for calculating external information is:

[0049]

[0050] Among them, ⊙ is the Hadamard product.

[0051] Further, in step seven, when the target user adopts 2 J For QAM modulation, a constellation point represents J bits, and the symbol The probability corresponding to the kth constellation point for:

[0052]

[0053] Among them, c k represents the kth constellation point, and |x| represents the modulus of the complex number x. The posterior mean and variance are:

[0054]

[0055] The calculation of the external information of module B in step 8 includes:

[0056] Average the posterior variances of different users within a sub-block:

[0057]

[0058] Then the posterior variance is The posterior mean is concatenated into a matrix form The element m′ in row n is The calculation formula for module B external information is:

[0059]

[0060] Among them, ⊙ is the Hadamard product.

[0061] Another object of the present invention is to provide a receiver control system in a burst interference scenario applying the receiver control method in a burst interference scenario, the receiver control system in the burst interference scenario comprising:

[0062] An MMSE-IRC estimation module A is configured to estimate the covariance matrix of interference using the received signal on the silent carrier, and perform MMSE-IRC estimation based on the estimated covariance matrix;

[0063] The soft demodulation noise reduction module B is used to reduce the noise of the estimated value by using the constellation diagram information of the target symbol.

[0064] Another object of the present invention is to provide a computer device, which includes a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the receiver control method in the sudden interference scenario.

[0065] Another object of the present invention is to provide a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the processor executes the steps of the receiver control method in the sudden interference scenario.

[0066] Another object of the present invention is to provide an information data processing terminal, which is used to implement the receiver control system in the sudden interference scenario.

[0067] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0068] In burst interference scenarios, the interference on some data symbols is not homologous to the interference on pilot symbols. Traditional interference suppression frameworks struggle to obtain a more accurate interference covariance matrix. Algorithms based on message passing frameworks are limited by the strength of prior information and often require multiple iterations to converge to a good result. The carrier muting scheme designed in this invention eliminates the need to send data symbols on some subcarriers. This allows it to collect a small amount of relatively accurate interference and use it to estimate the interference covariance matrix. This is then combined with the target user's constellation information for noise reduction. The algorithm can converge within a relatively small number of iterations and achieve excellent performance.

[0069] The present invention proposes a carrier muting scheme to address the problem that the receiver lacks prior information on burst interference. Specifically, it refers to muting a small number of subcarriers in the OFDM system, and the target user does not send a signal on the muted carrier, in order to obtain a more accurate interference signal. The signal observed on the muted carrier contains only two parts: burst interference and background white noise, while on other normal carriers it contains three parts: target signal, interference and noise. The signal collected on the muted carrier contains more accurate interference information, and reasonable use can effectively improve the efficiency of interference elimination. The present invention uses the interference on the muted carrier to estimate the covariance matrix and use it for demodulation. The demodulation part includes two modules, namely MMSE-IRC estimation module A and soft demodulation noise reduction module B; MMSE-IRC estimation of the target signal is performed in module A, and constellation diagram information is used in module B to reduce the noise of the input estimate; the two modules are alternately iterated until the algorithm converges.

[0070] The present invention sets a small number of silent carriers to collect information on sudden interference, uses the received signals on the silent carriers to estimate the covariance matrix of the sudden interference, and then designs two modules for iteration based on the constellation diagram information of the target symbol. The algorithm effectively eliminates sudden interference and greatly improves the receiver demodulation performance.

[0071] When many symbols in a data frame are subject to burst interference, the carrier muting scheme proposed in the present invention can effectively suppress interference. Under high-order modulation (64QAM and above), the performance gain is obvious, and the gap with the interference-free situation can be controlled within 1.5dB. The increase in the modulation order has a relatively weak impact on the algorithm performance.

[0072] Does the technical solution of the present invention solve the technical problems that people have always been eager to solve but have never been successful: the problem of burst interference has a long history in wireless communication systems, but there has always been a lack of better solutions, especially means to directly suppress or eliminate interference at the receiving end. With the reduction of cell radius and the increase of transmitter power in 5G networks, this problem occurs more frequently, especially under high-order modulation, the performance of the receiver deteriorates seriously, which seriously limits the performance of the communication system. The technical solution of the present invention is based on an iterative algorithm designed based on carrier muting, which can effectively collect interference information, and the noise reduction module is designed in combination with the constellation diagram information of the target data. The noise can be effectively eliminated through iteration. Even when there are many interfered data symbols, it can still achieve quite excellent performance under high-order modulation, which well solves the problem of system performance deterioration caused by burst interference under high-order modulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0074] Figure 1 This is a flow chart of a receiver control method in a burst interference scenario provided by an embodiment of the present invention;

[0075] Figure 2 This is a structural block diagram of a receiver provided by an embodiment of the present invention;

[0076] Figure 3 This is a diagram showing the BLER performance of the 64QAM demodulation algorithm provided by an embodiment of the present invention;

[0077] Figure 4 This is a diagram of the BLER performance of the demodulation algorithm under 256QAM provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0078] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0079] In order to solve the problems existing in the prior art, the present invention provides a receiver control method, system, device and terminal in a sudden interference scenario. The present invention is described in detail below with reference to the accompanying drawings.

[0080] In order to enable those skilled in the art to fully understand how to implement the present invention, this section provides an explanatory embodiment that expands on the technical solutions of the claims.

[0081] like Figure 1 As shown, the receiver control method in a burst interference scenario provided by an embodiment of the present invention includes the following steps:

[0082] S101, setting a small number of silent carriers to collect information on sudden interference;

[0083] S102, using the received signal on the silent carrier to estimate the covariance matrix of the burst interference and use it for demodulation;

[0084] S103, designing MMSE-IRC estimation module A and soft demodulation noise reduction module B based on the constellation information of the target symbol; performing MMSE-IRC estimation on the target signal in module A, and performing noise reduction on the input estimate using the constellation information in module B; alternating iterations between the two modules until convergence.

[0085] As a preferred embodiment, the receiver control method in a burst interference scenario provided by the embodiment of the present invention specifically includes the following steps:

[0086] S1. System modeling: There are T i OFDM data symbols are affected by burst interference, and the location of the interference is known (assuming that the interference does not occur on the pilot symbol), and the system frequency domain bandwidth is K = 12N RB subcarriers, N RB is the number of resource blocks (RBs). Assume that the number of receiving antennas at the base station is N r , the target signal stream number is N s , the number of interference signal streams is N i , the base station received signal on the kth subcarrier of the tth data symbol can be expressed as:

[0087]

[0088] in, is the target user channel, To interfere with user channels, is the target signal, is the interference signal, is white noise.

[0089] S2. Block model: Considering the correlation of channels on adjacent carriers, the adjacent R RBs are regarded as a sub-block, and the system is divided into Q = N EB / R sub-blocks, and T i The same sub-blocks of OFDM symbols are spliced ​​together, that is, the dimension of each sub-block is N r ×M, where M=KT i / Q, the received signal of the mth column in the qth sub-block is:

[0090] y q，m =H q，m s q，m +H I，q，m s I，q，m +n q，m

[0091] =H q，m s q，m +l q，m +n q，m

[0092] Wherein, the subscripts q and m correspond to the qK / Q+mod(m-1, K / Q)+1th carrier on the ceil(mQ / K)th OFDM data symbol affected by the burst interference, ceil(x) means rounding up x, mod(x, y) means the value of x modulo y, lq，m =H I，q，m s I，q，m Indicates an interference signal.

[0093] S3, Carrier Silence: Now set P silent carriers in each sub-block, and the positions of the silent carriers are evenly distributed in M ​​columns within the sub-block. That is, in the system, one carrier does not send the target signal every M / P sub-carriers. The received signal on the silent carrier is:

[0094] l mute，q，p =l q，p +n q，p ,

[0095] The subscript p corresponds to the (p-1)M / P+1th column signal in the sub-block. The received signal on the silent carrier is spliced ​​into a matrix form.

[0096] The received signal on a normal carrier is:

[0097] y q，m′ =H q，m′ s q，m′ +l q，m′ +n q，m′ ,

[0098] Where m′≠p corresponds to the subscript of the non-silent carrier. The received signal on the normal carrier is spliced ​​into a matrix form. The target symbol is represented as a matrix In the subsequent steps, each sub-block is processed separately and the processing steps are the same. For the sake of simplicity in symbolic representation, the sub-block subscript q is omitted in the following content.

[0099] S4. Receiver parameter initialization: in represents the prior information of the target symbol S in module A, is the prior value The prior variance of N s ×1 vector, meaning that different user target symbol estimates within the same sub-block have different variances. In subsequent steps, the abbreviation "pri" for the superscript "prior" represents prior information, "post" for the superscript "posterior" represents posterior information, and "ext" for the superscript "extrinsic" represents extrinsic information. Different superscripts for the same symbol distinguish the information category. Subscripts A and B indicate the modules A and B to which the corresponding symbol belongs, respectively.

[0100] S5. MMSE-IRC estimation module A: In module A, the covariance matrix of interference is estimated using the received signal on the silent carrier, and then MMSE-IRC estimation is performed based on the estimated covariance matrix.

[0101] S51, using L mute The estimated interference covariance matrix is:

[0102]

[0103] Where P is the number of silent carriers in a single sub-block. To solve the rank deficiency problem when the number of estimated samples is smaller than the dimension of the covariance matrix, the noise floor is loaded as:

[0104]

[0105] in, is the background white noise energy intensity, and I is the unit matrix.

[0106] S52. Perform MMSE-IRC estimation on each column in the sub-block. The posterior mean and variance of the target symbol are:

[0107]

[0108]

[0109] in, It means that the diagonal matrix is ​​formed with vector x as the diagonal element. And diag(X) means taking the diagonal elements of matrix X as column vectors.

[0110] S6. Calculation of external information of module A: First, average the posterior variance of different users in the sub-block:

[0111]

[0112] The formula for calculating external information is:

[0113]

[0114] Where ⊙ is the Hadamard product. Then the extrinsic information of the target symbol is input into module B.

[0115] S7, soft demodulation noise reduction module B: In module B, the constellation diagram information of the target symbol is used to estimate the value Noise reduction, its n rows and m′ columns are Its variance is Right now The nth element of . Assume that the target user adopts 2 J For QAM modulation, a constellation point represents J bits, and the symbol The probability corresponding to the kth constellation point for:

[0116]

[0117] Among them, ck represents the kth constellation point, and |x| represents the modulus of the complex number x. The posterior mean and variance are:

[0118]

[0119] S8, Module B external information calculation: First, average the posterior variance of different users in a sub-block:

[0120]

[0121] Then the posterior variance is The posterior mean is concatenated into a matrix form The element m′ in the nth row is The calculation formula for module B external information is:

[0122]

[0123] Where ⊙ is the Hadamard product. Then the external information mean and variance of module B are returned to module A.

[0124] S9. If the algorithm converges or reaches the preset maximum number of iterations, the process ends; otherwise, the process proceeds to step S52.

[0125] The receiver control system in a sudden interference scenario provided by an embodiment of the present invention includes:

[0126] An MMSE-IRC estimation module A is configured to estimate the covariance matrix of interference using the received signal on the silent carrier, and perform MMSE-IRC estimation based on the estimated covariance matrix;

[0127] The soft demodulation noise reduction module B is used to reduce the noise of the estimated value by using the constellation diagram information of the target symbol.

[0128] In order to prove the creativity and technical value of the technical solution of the present invention, this section provides application examples of the claimed technical solution on specific products or related technologies.

[0129] 1. Under special weather conditions, the refractive index of the ionosphere changes. Radio signals are repeatedly refracted in the ionosphere and can be transmitted to distant areas with minimal energy attenuation. When this occurs, it can cause sudden interference to remote base stations.

[0130] 2. If different communication standards exist in one or several adjacent cells, such as cells where FDD and TDD systems coexist, sudden interference may occur between different standards.

[0131] The embodiments of the present invention have achieved some positive effects during the development or use process, and indeed have great advantages compared with the existing technology. The following content describes them in conjunction with data, charts, etc. of the experimental process.

[0132] The structural block diagram of the receiver provided by the embodiment of the present invention is as follows Figure 2 As shown, it includes the MMSE-IRC estimation module A and the soft demodulation noise reduction module B. The algorithm simulation channel is the Urban Macro (UMa) scenario channel described in Section 7.5 of the 3GPP 38.901 standard. The parameter settings refer to the UMa scenario NLOS column in Table 7.5-6 Part-1 of the standard. The number of base station receiving antennas in the simulation is N r =64, target user flow number N s =8, number of burst interference flows N i =8, the burst interference IoT is 10dB / stream, the total number of OFDM data symbols in a TTI is T=12, and the number of data symbols affected by burst interference is T i =7, the system bandwidth is N RB = 24 RBs, a total of K = 288 subcarriers, R = 4 RBs as a subblock, the system is divided into Q = 6 subblocks, the modulation mode is 64QAM or 256QAM, the channel coding adopts LDPC coding, the coding rate is 3 / 4, and all OFDM data symbols in a single TTI are encoded as one codeword. In addition, because the position of the burst interference is known, the data symbols that are not affected by the burst interference are directly demodulated using the MMSE-IRC algorithm, and the data symbols affected by the burst interference are demodulated using the algorithm designed in the present invention, and the maximum number of iterations is set to 3. Under the current configuration, the specific implementation method of the receiver control method in the burst interference scenario provided by the embodiment of the present invention is as follows:

[0133] S1. System modeling: There are T i = 7 OFDM data symbols are affected by burst interference, and the location of the interference is known (assuming that the interference does not occur on the pilot symbol), and the system frequency domain bandwidth is K = 12N RB = 288 subcarriers, N RB =4 is the number of resource blocks (RB). Assume that the number of receiving antennas at the base station is N r =64, the target number of signal streams is N s =8, the number of interference signal streams is N i =8, the base station received signal on the k-th subcarrier of the t-th data symbol can be expressed as:

[0134]

[0135] in, is the target user channel, To interfere with user channels, is the target signal, is the interference signal, is white noise.

[0136] S2. Block model: Considering the correlation of channels on adjacent carriers, the adjacent R = 4 RBs are regarded as a sub-block, and the system is divided into Q = 6 sub-blocks. At the same time, T i = 7 OFDM symbols are spliced ​​together, that is, each sub-block has a dimension of 64×336. The m-th column received signal in the q-th sub-block is:

[0137] y q，m =H q，m s q，m +H I，q，m s I，q，m +n q，m

[0138] =H q，m s q，m +l q，m +n q，m

[0139] Wherein, the subscripts q and m correspond to the 48q+mod(m-1, 48)+1th carrier on the ceil(m / 48)th OFDM data symbol affected by the burst interference, ceil(x) means rounding up x, mod(x, y) means the value of x modulo y, l q，m =H I，q，m s I，q，m Indicates an interference signal.

[0140] S3. Carrier muting: Now, P = 84 muted carriers are set in each sub-block. The positions of the muted carriers are evenly distributed in M ​​= 336 columns in the sub-block. That is, every M / P = 4 sub-carriers in the system, one carrier does not send the target signal. The received signal on the muted carrier is:

[0141] l mute，q，p =l q，p +n q，p ,

[0142] The subscript p corresponds to the 4(p-1)+1th column signal in the sub-block. The received signal on the silent carrier is spliced ​​into a matrix form.

[0143] The received signal on a normal carrier is:

[0144] y q，m′ =H q，m′ s q，m′ +l q，m′ +n q，m′ ,

[0145] Where m′≠p corresponds to the subscript of the non-silent carrier. The received signal on the normal carrier is spliced ​​into a matrix form. The target symbol is represented as a matrix In the subsequent steps, each sub-block is processed separately and the processing steps are the same. For the sake of simplicity in symbolic representation, the sub-block subscript q is omitted in the following content.

[0146] S4. Receiver parameter initialization: in represents the prior information of the target symbol S in module A, is the prior value The prior variance is an 8×1 vector, indicating that different user target symbol estimates within the same sub-block have different variances. In subsequent steps, the abbreviation "pri" (for "prior") denotes prior information, "post" (for "posterior") denotes posterior information, and "ext" (for "extrinsic") denotes extrinsic information. Different superscripts for the same symbol distinguish the information category. Subscripts A and B denote the modules A and B to which the corresponding symbol belongs, respectively.

[0147] S5. MMSE-IRC estimation module A: In module A, the covariance matrix of interference is estimated using the received signal on the silent carrier, and then MMSE-IRC estimation is performed based on the estimated covariance matrix.

[0148] S51, using L mute The estimated interference covariance matrix is:

[0149]

[0150] Where P = 84 is the number of silent carriers in a single sub-block. To solve the rank deficiency problem when the number of estimated samples is smaller than the dimension of the covariance matrix, the noise floor is loaded as:

[0151]

[0152] in, is the background white noise energy intensity, and I is the unit matrix.

[0153] S52. Perform MMSE-IRC estimation on each column in the sub-block. The posterior mean and variance of the target symbol are:

[0154]

[0155]

[0156] in, It means that the diagonal matrix is ​​formed with vector x as the diagonal element. And diag(X) means taking the diagonal elements of matrix X as column vectors.

[0157] S6. Calculation of external information of module A: First, average the posterior variance of different users in the sub-block:

[0158]

[0159] The formula for calculating external information is:

[0160]

[0161] Where ⊙ is the Hadamard product. Then the extrinsic information of the target symbol is input into module B.

[0162] S7, soft demodulation noise reduction module B: In module B, the constellation diagram information of the target symbol is used to estimate the value Noise reduction, its n rows and m′ columns are Its variance is Right now The nth element of . Assume that the target user adopts 2 J = 64-order QAM modulation, then one constellation point represents J = 6 bits, symbol The probability corresponding to the kth constellation point for:

[0163]

[0164] Among them, c k represents the kth constellation point, and |x| represents the modulus of the complex number x. The posterior mean and variance are:

[0165]

[0166] S8, Module B external information calculation: First, average the posterior variance of different users in a sub-block:

[0167]

[0168] Then the posterior variance is The posterior mean is concatenated into a matrix form The element m′ in the nth row is The calculation formula for module B external information is:

[0169]

[0170] Where ⊙ is the Hadamard product. Then the external information mean and variance of module B are returned to module A.

[0171] S9. If the algorithm converges or reaches the preset maximum number of iterations, the process ends; otherwise, the process proceeds to step S52.

[0172] Figure 3 and Figure 4The BLER performance curves for 64QAM and 256QAM modulation are shown, respectively, when seven OFDM data symbols are subject to burst interference within a data frame. The horizontal axis represents the target user signal strength relative to the noise floor, and the vertical axis represents the data demodulation BLER. The "mute-scheme" curve corresponds to the carrier muting scheme proposed in this invention, the "interference-free" curve corresponds to the case where no data symbols are subject to burst interference, the "C-TMP-Opt" curve represents the result of 10 iterations of an algorithm designed based on a message passing framework, which primarily leverages the constellation information of the target signal and the low-rank nature of the interference signal, and the "LMMSE" curve corresponds to the case where the burst interference is treated as white noise.

[0173] At BLER = 0.1, when the modulation mode is 64QAM, the mute-scheme achieves a 14dB performance gain over the LMMSE algorithm and a 5.5dB performance gain over the C-TMP-Opt algorithm, and the performance gap between the mute-scheme and the non-interference case is controlled within 1.5dB; when the modulation order increases to 256QAM, the gap between the mute-scheme and the non-interference case is still less than 1.5dB, and the gap between the mute-scheme and the LMMSE algorithm remains at around 14dB, but it achieves a 7dB gain over the C-TMP-Opt algorithm, an improvement of 1.5dB over the 64QAM case. The main reason is that as the modulation order increases, the density of constellation points increases, which reduces its noise reduction ability, while the C-TMP-Opt algorithm relies on the noise reduction ability of the constellation diagram, resulting in some performance loss. The carrier muting scheme proposed in the present invention uses part of the carrier to obtain information about the burst interference, greatly reducing the algorithm's dependence on constellation information and no longer being limited by the modulation order and constellation density.

[0174] In summary, when many symbols in the data frame are subject to burst interference, the carrier muting scheme proposed in the present invention can effectively suppress interference. Under high-order modulation (64QAM and above), the performance gain is obvious, and the gap with the interference-free situation can be controlled within 1.5dB. The increase in the modulation order has a relatively weak impact on the algorithm performance.

[0175] It should be noted that the embodiments of the present invention can be implemented by hardware, software, or a combination of software and hardware. The hardware portion can be implemented using dedicated logic; the software portion can be stored in a memory and executed by an appropriate instruction execution system, such as a microprocessor or dedicated design hardware. Those skilled in the art will understand that the above-mentioned devices and methods can be implemented using computer-executable instructions and / or contained in processor control code, for example, such as a carrier medium such as a disk, CD or DVD-ROM, a programmable memory such as a read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. The device and its modules of the present invention can be implemented by hardware circuits such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, etc., or programmable hardware devices such as field programmable gate arrays, programmable logic devices, etc., can also be implemented by software executed by various types of processors, or can be implemented by a combination of the above-mentioned hardware circuits and software, such as firmware.

[0176] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with this technical field within the technical scope disclosed by the present invention and within the spirit and principles of the present invention should be covered by the scope of protection of the present invention.

Claims

1. A receiver control method in a sudden interference scenario, characterized in that: include: A small number of silent carriers are set to collect information about burst interference, and the covariance matrix of the burst interference is estimated using the received signal on the silent carriers and used for demodulation; Based on the constellation information of the target symbol, an MMSE-IRC estimation module A and a soft demodulation noise reduction module B are designed. MMSE-IRC estimation module A performs MMSE-IRC estimation on the target signal, while soft demodulation noise reduction module B uses the constellation information to reduce the noise of module B's input prior information. Alternate iterations between the two modules are performed until convergence. The receiver control method in the burst interference scenario includes the following steps: Step 1: System modeling: There are T i OFDM data symbols are affected by burst interference. When the interference does not occur on the pilot symbol and the location of the interference is known, the system frequency domain bandwidth is K = 12N. RB subcarriers, N RB is the number of resource blocks; Step 2, block model: Considering the correlation of channels on adjacent carriers, the adjacent R RBs are regarded as a sub-block, and the system is divided into Q = N RB / R sub-blocks; at the same time, T i The same sub-blocks of OFDM symbols are concatenated, and the dimension of each sub-block is N r ×M, where M=KT i / Q; Step 3: Carrier muting: P silent carriers are set in each sub-block. The positions of the silent carriers are evenly distributed in M ​​columns within the sub-block. In the system, one carrier does not send the target signal for every M / P sub-carriers. The received signal on the silent carriers and the received signal on the normal carriers are determined. Step 4: Initialize receiver parameters: in represents the prior information of the target symbol S in module A, Prior information The prior variance is N s ×1 vector, different user target symbol prior information in the same sub-block corresponds to different variances; Step 5: Construct an MMSE-IRC estimation module A: use the received signal on the silent carrier to estimate the covariance matrix of the interference, and perform MMSE-IRC estimation based on the estimated covariance matrix; Step 6: Calculate the external information of module A: Take the average of the posterior variance of different users in the sub-block to calculate the external information of module A, and then input the external information of the target symbol into module B; Step 7: Construct soft demodulation noise reduction module B: In module B, the constellation diagram information of the target symbol is used to determine the prior information of the target symbol S in module B. Noise reduction, n rows and m′ columns elements are The variance is The nth element of ; Step 8: Calculate the extrinsic information of module B: average the posterior variances of different users in a sub-block, and then return the extrinsic information mean and variance of module B to module A; Step 9: If the algorithm converges or reaches the preset maximum number of iterations, the algorithm ends. Otherwise, the algorithm proceeds to step 5 to perform MMSE-IRC estimation on each column in the sub-block to determine the posterior mean and variance of the target symbol. In step 4 and subsequent steps, the abbreviation "pri" of the superscript "prior" is used to represent prior information, the abbreviation "post" of the superscript "posterior" is used to represent posterior information, and the abbreviation "extrinsic" of the superscript "extrinsic" is used to represent external information. Different superscripts for the same symbol are used to distinguish the information category. The subscripts A and B respectively indicate the modules A and B to which the corresponding symbol belongs. In step 1, when the number of receiving antennas at the base station is N r , the target signal stream number is N s , the number of interference signal streams is N i , the base station received signal on the k1-th subcarrier of the t-th data symbol is expressed as: in, is the target user channel, To interfere with user channels, is the target signal, is the interference signal, is white noise; In step 2, the received signal of the mth column in the qth sub-block is: Wherein, the subscripts q and m correspond to the qK / Q+mod(m-1, K / Q)+1th carrier on the ceil(mQ / K)th OFDM data symbol affected by the burst interference, ceil(x) means rounding up x, and mod(x, y) means the value obtained by taking the modulus of x on y. Indicates interference signal; In step 3, the received signal on the silent carrier is: L mute，q，p =l q，p +n q，p , Wherein, the subscript p corresponds to the (p-1)M / P+1th column signal in the sub-block; the received signal on the silent carrier is spliced ​​into a matrix form The received signal on a normal carrier is: y q，m′ =H q，m′ s q，m′ +l q，m′ +n q，m′ , Among them, m′≠p corresponds to the subscript of the non-silent carrier; the received signal on the normal carrier is spliced ​​into a matrix form The target symbol is represented as a matrix In the subsequent steps, the sub-block subscript q is omitted; The MMSE-IRC estimation module A in step 5 estimates the covariance matrix of the interference using the received signal on the silent carrier, and performs MMSE-IRC estimation based on the estimated covariance matrix, including: (1) Using L mute The estimated interference covariance matrix is: Where P is the number of silent carriers in a single sub-block. To solve the rank deficiency problem when the number of estimated samples is smaller than the dimension of the covariance matrix, the noise floor is loaded as: in, is the background white noise energy intensity, I is the unit matrix; (2) Perform MMSE-IRC estimation on each column in the sub-block, and the posterior mean and variance of the target symbol are: in, represents the diagonal matrix generated with vector x as the diagonal element, And diag(X) means taking the diagonal elements of matrix X as column vectors; The calculation of the external information of module A in step 6 includes: Take the average of the posterior variance of different users in the sub-block: The formula for calculating external information is: Among them, ⊙ is the Hadamard product; In step seven, when the target user adopts 2 J For QAM modulation, a constellation point represents J bits, and the symbol The probability corresponding to the kth constellation point for: Among them, c k represents the kth constellation point, |x| represents the modulus of the complex number x; the posterior mean and variance are: The calculation of the external information of module B in step 8 includes: Average the posterior variances of different users within a sub-block: Then the posterior variance is The posterior mean is concatenated into a matrix form The element m′ in row n is The calculation formula for module B external information is: Among them, ⊙ is the Hadamard product.

2. A receiver control system in a sudden interference scenario using the receiver control method in a sudden interference scenario as claimed in claim 1, characterized in that: The receiver control system in the sudden interference scenario includes: An MMSE-IRC estimation module A is configured to estimate the covariance matrix of interference using the received signal on the silent carrier, and perform MMSE-IRC estimation based on the estimated covariance matrix; The soft demodulation noise reduction module B is used to reduce the noise of the estimated value by using the constellation diagram information of the target symbol.

3. A computer device, characterized in that: The computer device includes a memory and a processor, the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the steps of the receiver control method in the sudden interference scenario as claimed in claim 1.

4. A computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the processor executes the steps of the receiver control method in a sudden interference scenario as claimed in claim 1.

5. An information data processing terminal, characterized in that: The information data processing terminal is used to implement the receiver control system in the sudden interference scenario as described in claim 2.

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