WO2020216056A1

WO2020216056A1 - Channel estimation method and apparatus

Info

Publication number: WO2020216056A1
Application number: PCT/CN2020/083509
Authority: WO
Inventors: 李增; 李�杰; 黄�俊; 艾星星; 刘源; 池袖伟
Original assignee: 中兴通讯股份有限公司
Priority date: 2019-04-26
Filing date: 2020-04-07
Publication date: 2020-10-29
Also published as: CN111865840B; CN111865840A

Abstract

Disclosed are a channel estimation method and apparatus, the method comprising: constructing, according to an original channel estimation matrix, a first interference matrix of the ith first sub-carrier, wherein i is an integer between one and N_RE, and N_RE is the number of sub-carriers; and performing, according to the first interference matrix of the ith sub-carrier, interference reduction processing on an original channel estimation vector corresponding to the ith sub-carrier in the original channel estimation matrix to obtain a channel estimation vector, which is subjected to interference reduction, of the ith sub-carrier, wherein channel estimation vectors, which are subjected to interference reduction, of all the sub-carriers constitute a channel estimation matrix subjected to interference reduction.

Description

Channel estimation method and device

Cross references to related applications

This application is filed based on a Chinese patent application with an application number of 201910346125.2 and an application date of April 26, 2019, and claims the priority of the Chinese patent application. The entire content of the Chinese patent application is hereby incorporated by reference into this application.

Technical field

The embodiments of the present invention relate to, but are not limited to, communication technologies, in particular to a channel estimation method and device.

Background technique

Channel estimation is an important operation step in Long Term Evolved (LTE) and 5G communication systems, and the accuracy of its estimation affects the throughput of the cell. For the data channel, taking the Physical Uplink Shared Channel as an example, the channel estimation accuracy of the pilot directly affects the demodulation performance of the data and thus the uplink traffic. For reference signals, taking Sounding Reference Signal (SRS, Sounding Reference Signal) as an example, the accuracy of pilot channel estimation will affect the downlink shaping performance, and indirectly affect the downlink traffic.

In an actual communication system, the interference between different cells is more serious, and greater interference will affect the accuracy of the pilot channel estimation, thereby directly or indirectly reducing the cell throughput.

The main method to deal with interference in the traditional channel estimation process is to use the least square (LS, Least Square) estimation of the pilot frequency, and use the uniform distribution of interference and noise in the time domain to transform the inverse fast Fourier transform. (IFFT, Inverse Fast Fourier Transform) to the time domain to add a window to intercept the signal or to perform low-pass Finite Impulse Response (FIR, Finite Impulse Response) filtering in the frequency domain to achieve the purpose of removing interference. In fact, this method cannot effectively distinguish between noise and signal, and the interference is not completely removed for the part where the signal and the interference are superimposed. When the interference power is large, the accuracy of the channel estimation of the pilot is severely reduced, which reduces the demodulation performance or downlink shaping performance.

Summary of the invention

The embodiment of the present invention provides a channel estimation method and device, which can effectively remove interference and improve the accuracy of pilot channel estimation, thereby directly or indirectly improving cell throughput.

The embodiment of the present invention provides a channel estimation method, including:

The first interference matrix of the i-th subcarrier constructed according to the original channel estimation matrix; where i is an integer between 1 and N _RE , and N _RE is the number of subcarriers;

According to the first interference matrix of the i-th subcarrier, perform interference reduction processing on the original channel estimation vector corresponding to the i-th subcarrier in the original channel estimation matrix to obtain the interference-reduced channel estimation vector of the i-th subcarrier. The interference-reduced channel estimation vector of the subcarriers constitutes the interference-reduced channel estimation matrix.

In the first round of calculation, the first interference matrix of the i-th subcarrier calculated in the first round constructed from the original channel estimation matrix; where i is an integer between 1 and N _RE , and N _RE is the number of subcarriers ；

Perform interference reduction processing on the original channel estimation vector corresponding to the i-th sub-carrier in the original channel estimation matrix according to the first interference matrix of the i-th subcarrier calculated in the first cycle to obtain the first interference matrix calculated in the first cycle. The interference-reduced channel estimation vectors of i subcarriers, and the interference-reduced channel estimation vectors of all subcarriers calculated in the first cycle constitute the interference-reduced channel estimation matrix calculated in the first cycle;

In the j-th cycle calculation, the first interference matrix of the i-th subcarrier calculated in the j-th cycle constructed based on the original channel estimation matrix and the channel estimation matrix after interference reduction calculated in the (j-1)th cycle ; Among them, j is an integer between 2 and M, and M is the maximum number of iterations;

Perform interference reduction processing on the original channel estimation vector corresponding to the i-th sub-carrier in the original channel estimation matrix according to the first interference matrix of the i-th sub-carrier calculated in the j-th cycle to obtain the first interference matrix calculated in the j-th cycle The interference-reduced channel estimation vectors of i subcarriers, and the interference-reduced channel estimation vectors of all subcarriers calculated in the jth cycle constitute the interference-reduced channel estimation matrix calculated in the jth cycle.

An embodiment of the present invention provides a channel estimation device, which includes a processor and a computer-readable storage medium. The computer-readable storage medium stores instructions. When the instructions are executed by the processor, any of the foregoing A channel estimation method.

The embodiment of the present invention provides a computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, the steps of any of the foregoing channel estimation methods are implemented.

Other features and advantages of the embodiments of the present invention will be described in the following description, and partly become obvious from the description, or understood by implementing the embodiments of the present invention. The objectives and other advantages of the embodiments of the present invention can be realized and obtained through the structures specifically pointed out in the specification, claims and drawings.

Description of the drawings

The accompanying drawings are used to provide a further understanding of the technical solutions of the embodiments of the present invention, and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the technical solutions of the embodiments of the present invention, and do not constitute a technical solution to the embodiments of the present invention. limits.

Fig. 1 is a flowchart of a channel estimation method proposed by an embodiment of the present invention;

2 is a flowchart of a channel estimation method proposed by another embodiment of the present invention;

FIG. 3 is a schematic diagram of the structural composition of a channel estimation device proposed by another embodiment of the present invention;

FIG. 4 is a schematic diagram of the structural composition of a channel estimation device provided by another embodiment of the present invention.

Fig. 5 is a schematic diagram of the structural composition of a channel estimation device proposed by another embodiment of the present invention.

Detailed ways

The embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. It should be noted that, in the case of no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other arbitrarily.

The steps shown in the flowchart of the drawings may be executed in a computer system such as a set of computer-executable instructions. And, although a logical sequence is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than here.

Referring to Fig. 1, an embodiment of the present invention provides a channel estimation method, including:

Step 100: A first interference matrix of the i-th subcarrier constructed according to the original channel estimation matrix; where i is an integer between 1 and N _RE , and N _RE is the number of subcarriers.

In the embodiment of the present invention, the original channel estimation matrix may be the original LS estimation matrix of the pilot signal.

In the embodiment of the present invention, the first interference matrix of the i-th subcarrier constructed according to the original channel estimation matrix includes:

Determine the second interference matrix according to the original channel estimation matrix;

The first interference matrix of the i-th subcarrier is constructed according to the second interference matrix.

Wherein, determining the second interference matrix according to the original channel estimation matrix includes:

Transform the original channel estimation matrix into the time domain to obtain the original channel estimation matrix in the time domain;

Performing first preprocessing on the original channel estimation matrix in the time domain, and transforming the channel estimation matrix after the first preprocessing into the frequency domain to obtain the second interference matrix;

Wherein, the performing the first preprocessing on the original channel estimation matrix in the time domain includes: for the original channel estimation vector corresponding to each antenna in the original channel estimation matrix in the time domain, calculating the original channel estimation vector corresponding to the antenna The signal inside the window of the noise window is set to zero, and the signal outside the window of the noise window remains.

For example, remember the original channel estimation matrix as

N _Ant represents the number of antennas, and N _RE represents the number of subcarriers. IFFT the original channel estimation matrix to the time domain to obtain the original channel estimation matrix in the time domain

N _T represents the time length, N _T = N _RE.

It should be noted that the original channel estimation matrix includes two dimensions, one is the antenna and the other is the subcarrier; the original time-domain channel estimation matrix also includes two dimensions, one is the antenna, the other is time, and the time dimension It is equal to the length of the sub-carrier dimension.

Set a noise window. The position of the noise window is determined according to the code score of the pilot. The length of the noise window can be set according to requirements; the noise window divides the original channel estimation vector corresponding to each antenna in the original channel estimation matrix h in the time domain into two part: W _out of the window signal and the window signal W _in, the length of the data corresponding to the window W _out signal referred to as L _out, the data length of the windowed signal is denoted as W _in the corresponding L _in.

It should be noted that the original channel estimation vector corresponding to one antenna includes the original channel estimation values of all sub-carriers corresponding to the original channel estimation matrix.

For the original channel estimation vector corresponding to each antenna in the original channel estimation matrix in the time domain, zero the signal in the window of the original channel estimation vector and keep the signal outside the window. Perform FFT transformation on the channel estimation matrix obtained after the above processing to obtain the second Interference matrix, the second interference matrix includes the interference signal vectors of all sub-carriers.

Is the interference signal vector of the i-th subcarrier.

Wherein, constructing the first interference matrix of the i-th subcarrier according to the second interference matrix includes:

In the second interference matrix, the interference signal vector of the i-th subcarrier, the interference signal vector of the Ni subcarriers to the left of the _i- th subcarrier, and the interference signal vector of the Ni subcarriers to the right of the _i- th subcarrier The interference signal vector is spliced into the first interference matrix of the i-th subcarrier, namely

N _i is an integer greater than or equal to 0;

among them,

Is the interference vector of the (i-N _i )th subcarrier,

Is the interference vector of the (i+N _i )th subcarrier.

Where, N _i values can be dynamically selected with the original channel estimates according to the interference signal power of interference signal power matrix or the i-th subcarrier. When N _{i is} relatively large, the subspace dimension of the first interference matrix of the i-th subcarrier is larger, and the orthogonal projection can eliminate more interference components, and at the same time, it is possible to eliminate more signal components. In the high interference signal power scene The positive gain for canceling interference is greater than the negative gain for canceling the signal, and there is overall gain, but in the case of low interference signal power, the positive gain for canceling interference is less than the negative gain for canceling the signal, and there is overall negative gain. When the N _{i is} relatively small, the orthogonal projection eliminates less interference components, and at the same time eliminates the signal components. The gain is small in the high interference power scene, but in the low interference rate scene there is small gain and no Negative gain. Therefore, in principle N _i is selected to select a large value in a high interference signal power condition, to obtain a large gain, the interference signal power at a low, select a smaller gain value obtained while avoiding small N _i Larger brings negative gain. That is, for the i th subcarrier, the interference signal power corresponding to the high value of N _i N _i is greater than the value corresponding to the low-interference signal power.

The Ni corresponding to different subcarriers may be the same or different.

Among them, the calculation method of the average interference signal power of the original channel estimation matrix is consistent with the calculation method described later, and will not be repeated here.

The interference signal power of the i-th subcarrier can also be calculated using a similar method.

Step 101: Perform interference reduction processing on the original channel estimation vector corresponding to the i-th sub-carrier in the original channel estimation matrix according to the first interference matrix of the i-th sub-carrier to obtain an interference-reduced channel estimate of the i-th sub-carrier Vector, the channel estimation vector after interference reduction of all subcarriers constitutes the channel estimation matrix after interference reduction.

In the embodiment of the present invention, the original channel estimation vector corresponding to a subcarrier in the original channel estimation matrix includes the original channel estimation values of all antennas corresponding to the subcarrier.

In the embodiment of the present invention, interference reduction processing is performed on the original channel estimation vector corresponding to the i-th sub-carrier in the original channel estimation matrix according to the first interference matrix of the i-th sub-carrier to obtain the reduction of the i-th sub-carrier. The channel estimation vector after interference includes:

Calculating the projection matrix of the i-th sub-carrier according to the first interference matrix of the i-th sub-carrier;

Projecting the original channel estimation vector corresponding to the i-th sub-carrier according to the projection matrix of the i-th sub-carrier to obtain the interference-reduced channel estimation vector of the i-th sub-carrier.

Wherein, the projection matrix of the i-th sub-carrier may be directly calculated according to the first interference matrix of the i-th sub-carrier; or,

Perform singular value decomposition on the first interference matrix of the i-th subcarrier, and calculate the projection matrix of the i-th subcarrier according to the matrix containing the first K columns of the left singular matrix of the i-th subcarrier; where K is The number of singular values exceeding the singular value threshold.

In some embodiments, when N _{i is} greater than 0, the singular value decomposition is performed on the first interference matrix H _I1i of the i-th subcarrier, that is

Among them, U _Ii is the left singular matrix of the i-th subcarrier, Λ _Ii is a diagonal matrix composed of singular values of the i-th subcarrier, and V _Ii is the right singular matrix of the i-th subcarrier. Set a threshold of singular value, consider that all the left singular vectors corresponding to the singular value larger than the threshold on the diagonal of Λ _Ii are the main feature vectors of interference, that is, the first K columns of U _Ii , (K is the number of singular values exceeding the threshold ) As H _I2i .

In an embodiment of the present invention, the calculation of the projection matrix P _i of the i th sub-carrier can be carried out according to the formula of the orthogonal projection, orthogonal projection formula is as follows.

Wherein, P _i is the projection matrix of the i-th subcarrier, and H _I2i is the first interference matrix of the i-th subcarrier or the matrix of the first K columns of the left singular matrix containing the i-th subcarrier.

In the embodiment of the present invention, the original channel estimation vector H _LSi corresponding to the i-th subcarrier in the original channel estimation matrix is projected to obtain the original channel estimation vector corresponding to the i-th subcarrier after projection, which is the i-th subcarrier Channel estimation vector after interference reduction.

Among them, H _LSNewi is the interference-reduced channel estimation vector of the i-th subcarrier, H _LSi is the original channel estimation vector corresponding to the i-th subcarrier in the original channel estimation matrix, and P _i is the projection matrix of the i-th subcarrier.

The embodiment of the present invention effectively removes the interference of the original channel estimation matrix based on the first interference matrix, improves the accuracy of the pilot channel estimation, and directly or indirectly improves the cell throughput.

In another embodiment of the present invention, the method further includes:

Step 102: Determine a final channel estimation matrix according to the channel estimation matrix after interference reduction and the effective signal power change of the original channel estimation matrix.

In the embodiment of the present invention, determining the final channel estimation matrix according to the channel estimation matrix after interference reduction and the effective signal power change of the original channel estimation matrix includes at least one of the following:

When the ratio of the effective signal power of the reduced interference channel estimation matrix to the effective signal power of the original channel estimation matrix is less than the first preset threshold, it is considered that the effective signal has been eliminated more, and the final channel estimation matrix is determined Is the original channel estimation matrix, that is, the original channel estimation matrix before interference reduction is still used as the final channel estimation matrix;

When the ratio of the effective signal power of the reduced interference channel estimation matrix to the effective signal power of the original channel estimation matrix is greater than the first preset threshold, it is considered that the effective signal has been eliminated less, and the final channel estimation matrix is determined Is the channel estimation matrix after interference reduction, that is, the channel estimation matrix after interference reduction is used as the final channel estimation matrix.

Among them, the following methods can be used to calculate the effective signal power of the channel estimation matrix after interference reduction:

Transform the interference-reduced channel estimation matrix to the time domain to obtain the time-domain interference-reduced channel estimation matrix; for the interference-reduced channel estimation vector corresponding to each antenna in the time-domain interference-reduced channel estimation matrix, calculate The signal power in the noise window of the channel estimation vector after interference reduction corresponding to the antenna is taken as the effective signal power of the antenna; the average value of the effective signal power of all antennas minus the noise power in the converted window is taken as the interference reduction The effective signal power of the channel estimation matrix.

Among them, the following methods can be used to calculate the effective signal power of the original channel estimation matrix:

For the original channel estimation vector corresponding to each antenna in the original channel estimation matrix in the time domain, calculating the power of the signal in the window of the noise window of the original channel estimation vector corresponding to the antenna as the effective signal power of the antenna;

The average value of the effective signal power of all antennas minus the converted window noise power is used as the effective signal power of the original channel estimation matrix.

The embodiment of the present invention determines the final channel estimation matrix based on the change of the effective signal power before and after the interference is eliminated, which ensures the robustness of the interference elimination effect and filters out the negative gain brought by the spatially high correlation scene.

In another embodiment of the present invention, the method further includes:

When the original channel estimation matrix meets the requirements for interference cancellation, continue to perform the step of constructing the first interference matrix of the i-th subcarrier according to the original channel estimation matrix.

When the original channel estimation matrix does not meet the requirements for interference cancellation, conventional interference cancellation methods (such as the method described in the background art or other methods) are used for the original channel estimation matrix for interference cancellation, such as port separation, noise reduction, FFT Transformation and other processing.

In the embodiment of the present invention, the effect of the interference reduction method using interference orthogonal projection is mainly related to two factors: the estimation accuracy of the interference signal vector, and the first correlation between the interference signal vector and the effective signal vector. On the one hand, when the interference signal power is too small, the estimation accuracy of the interference signal vector is poor. At this time, the interference reduction method using the interference orthogonal projection can not accurately eliminate the interference and may also eliminate the effective signal, resulting in negative gain. On the other hand, when the first correlation between the interference signal vector and the effective signal vector is relatively high, the method of using interference orthogonal projection will eliminate the interference while also greatly eliminating the effective signal, which will also cause negative gain.

In a communication cell, whether there is interference, the magnitude of the interference, the first correlation between the interference signal vector, the interference signal vector and the effective signal vector is a random event. When the interference orthogonal projection method is used to eliminate the interference, In order to avoid the negative impact caused by low-interference and high-correlation scenarios, it is necessary to determine the power of the interference signal and the first correlation between the interference signal vector and the effective signal vector.

In other words, judging whether the original channel estimation matrix meets the requirements for interference cancellation includes:

Determining the first correlation between the interference signal power, the signal-to-noise ratio, the interference signal vector, and the effective signal vector of the original channel estimation matrix;

According to the interference signal power, the signal-to-noise ratio, the first correlation between the interference signal vector and the effective signal vector, it is determined whether the original channel estimation matrix meets the requirements for interference cancellation.

Specifically, when the interference signal power is greater than the second preset threshold, the signal-to-noise ratio is less than the third preset threshold, and the first correlation between the interference signal vector and the effective signal vector is less than the fourth preset threshold, the original The channel estimation matrix meets the requirements for interference cancellation;

When the interference signal power is less than the second preset threshold, or the signal-to-noise ratio is greater than the third preset threshold, or the first correlation between the interference signal vector and the effective signal vector is greater than the fourth preset threshold, determine the original channel estimation matrix Does not meet the requirements for interference cancellation.

The following introduces the calculation method of the first correlation between the interference signal power, the signal-to-noise ratio, the interference signal vector and the effective signal vector of the original channel estimation matrix.

(1) Interference signal power

For the original channel estimation vector corresponding to each antenna in the original channel estimation matrix in the time domain, calculate the power of the signal outside the window of the noise window of the original channel estimation vector corresponding to the antenna as the interference signal power of the antenna;

The average value of the interference signal power of all antennas is used as the interference signal power of the original channel estimation matrix.

For example, remember the original channel estimation matrix as

N _T represents the time length, N _T = N _RE.

The power of all signals outside the window of all antennas is averaged as an estimate of the interference signal power (ie, the power of the noise signal), denoted as P _ni , and the calculation formula is as follows:

Among them, n _Ant is the antenna index, and h(n _Ant , n ₁ ) is the original channel estimation value of the signal outside the window.

(2) Signal to noise ratio

For the original channel estimation vector corresponding to each antenna in the original channel estimation matrix in the time domain, calculate the power of the signal outside the window of the noise window of the original channel estimation vector corresponding to the antenna as the interference signal power of the antenna; The power of the signal in the noise window of the original channel estimation vector is used as the effective signal power of the antenna;

The average value of the interference signal power of all antennas is used as the interference signal power of the original channel estimation matrix, and the average value of the effective signal power of all antennas minus the noise power in the converted window is used as the effective signal power of the original channel estimation matrix;

The signal-to-noise ratio is calculated according to the interference signal power of the original channel estimation matrix and the effective signal power of the original channel estimation matrix.

For example, remember the original channel estimation matrix as

N _T represents the time length, N _T = N _RE.

The signal power in all windows of all antennas is power averaged and the converted noise power in the window is subtracted as an estimate of the effective signal power, which is P _s . Its calculation formula is as follows:

Among them, h(n _Ant ,n ₂ ) is the original channel estimation value of the signal in the window.

Finally, the signal-to-noise ratio SINR is estimated from P _s and P _ni : SINR=P _s /P _ni .

(3) The first correlation between the interference signal vector and the effective signal vector

In order to calculate the first correlation between the interference signal vector and the effective signal vector, the interference signal vector and the effective signal vector are first calculated.

Among them, the interference signal vector can be calculated according to the following method:

Perform a first preprocessing on the original channel estimation matrix in the time domain, and transform the channel estimation matrix after the first preprocessing into the frequency domain to obtain the second interference matrix, denoted as

The value of all antennas corresponding to each subcarrier in the second interference matrix is used as the interference signal vector of the subcarrier.

Among them, the effective signal vector can be calculated according to the following method:

Perform a second preprocessing on the original channel estimation matrix in the time domain, and transform the channel estimation matrix after the second preprocessing into the frequency domain to obtain an effective signal matrix, denoted as

The value of all antennas corresponding to each subcarrier in the effective signal matrix is taken as the effective signal vector of the subcarrier.

Wherein, the performing the second preprocessing on the original channel estimation matrix in the time domain includes: for the original channel estimation vector corresponding to each antenna in the original channel estimation matrix in the time domain, calculating the original channel estimation vector corresponding to the antenna The signal inside the window within the noise window is retained, and the signal outside the window outside the noise window is set to zero.

After obtaining the interference signal vector and effective signal vector of each subcarrier, for each subcarrier, calculate the second correlation between the interference signal vector and the effective signal vector corresponding to the subcarrier, that is, according to the formula

By calculation, the average value of the second correlations corresponding to all subcarriers is the first correlation between the desired interference signal vector and the effective signal vector.

In the embodiment of the present invention, interference cancellation is performed only when the original channel estimation matrix meets the requirements for interference cancellation, and the negative gain caused by scenarios that do not meet the interference cancellation requirements is filtered out, which further improves the accuracy of pilot channel estimation, thereby directly Or indirectly increase the cell throughput rate.

Referring to Fig. 2, an embodiment of the present invention provides a channel estimation method, including:

Step 200: In the first round of calculation, the first interference matrix of the i-th subcarrier calculated in the first round constructed according to the original channel estimation matrix; where i is an integer between 1 and N _RE , and N _RE is Number of subcarriers.

Step 201: Perform interference reduction processing on the original channel estimation vector corresponding to the i-th subcarrier in the original channel estimation matrix according to the first interference matrix of the i-th subcarrier calculated in the first cycle to obtain the first cycle The interference-reduced channel estimation vector of the i-th subcarrier is calculated, and the interference-reduced channel estimation vectors of all subcarriers calculated in the first cycle constitute the interference-reduced channel estimation matrix calculated in the first cycle.

The specific implementation process of step 200 and step 201 is the same as the specific implementation process of the foregoing embodiment, and will not be repeated here.

Step 202: In the j-th cycle calculation, the i-th subcarrier calculated in the j-th cycle is constructed according to the original channel estimation matrix and the interference-reduced channel estimation matrix calculated in the (j-1)th cycle. An interference matrix; where j is an integer between 2 and M, and M is the maximum number of iterations.

In the embodiment of the present invention, constructing the first interference matrix of the i-th subcarrier calculated in the j-th cycle according to the original channel estimation matrix and the channel estimation matrix after interference reduction calculated in the (j-1)-th cycle includes:

Determine the second interference matrix calculated in the jth cycle according to the original channel estimation matrix and the channel estimation matrix after interference reduction calculated in the (j-1)th cycle;

Construct the first interference matrix of the i-th subcarrier calculated in the j-th cycle according to the second interference matrix calculated in the j-th cycle.

Among them, determining the second interference matrix calculated in the jth cycle according to the original channel estimation matrix and the channel estimation matrix after interference reduction calculated in the (j-1)th cycle includes:

Transforming the interference-reduced channel estimation matrix calculated in the (j-1)th cycle into the time domain to obtain the interference-reduced channel estimation matrix calculated in the (j-1)th cycle in the time domain;

Perform a second preprocessing on the interference-reduced channel estimation matrix calculated in the (j-1)th cycle of the time domain, and transform the channel estimation matrix after the second preprocessing into the frequency domain to obtain the jth cycle Calculated effective signal matrix;

Calculate the second interference matrix calculated in the jth cycle according to the original channel estimation matrix and the effective signal matrix calculated in the jth cycle; specifically, subtract the jth time from the original channel estimation matrix The effective signal matrix calculated in a loop can obtain the second interference matrix calculated in the jth loop;

Wherein, the second preprocessing of the interference reduction channel estimation matrix calculated in the (j-1)th cycle of the time domain includes: the interference reduction calculated in the (j-1)th cycle of the time domain The original channel estimation vector corresponding to each antenna in the subsequent channel estimation matrix retains the signal within the noise window of the original channel estimation vector corresponding to the antenna, and zeros the signal outside the noise window.

For example, the channel estimation matrix after interference reduction calculated in the (j-1)th cycle is

N _Ant represents the number of antennas, and N _RE represents the number of subcarriers. The channel estimation matrix after interference reduction calculated in the (j-1)th cycle is transformed to the time domain by IFFT to obtain the (j-1)th cycle in the time domain. Calculated channel estimation matrix after interference reduction

N _T represents the time length, N _T = N _RE.

It should be noted that the interference reduction channel estimation matrix calculated in the (j-1)th cycle includes two dimensions, one is the antenna, and the other is the subcarrier; the time domain is calculated in the (j-1)th cycle The channel estimation matrix after interference reduction also includes two dimensions, one is the antenna and the other is time, and the length of the time dimension and the subcarrier dimension are equal.

Set a noise window. The position of the noise window is determined according to the code score of the pilot. The length of the noise window can be set according to requirements; the noise window is the interference reduction channel estimation matrix h calculated in the (j-1)th cycle of the time domain The original channel estimation vector corresponding to each antenna is divided into two parts: the signal outside the window W _out and the signal inside the window W _in . The data length corresponding to the signal outside the window W _out is recorded as L _out , and the data length corresponding to the signal inside the window W _in is recorded as L _in .

It should be noted that the original channel estimation vector corresponding to an antenna includes the original channel estimation values of all subcarriers corresponding to the antenna after the interference reduction channel estimation matrix calculated in the (j-1)th cycle.

For the original channel estimation vector corresponding to each antenna in the interference-reduction channel estimation matrix calculated in the (j-1)th cycle of the time domain, the window signal of the original channel estimation vector is retained, and the signal outside the window is set to zero. The channel estimation matrix obtained after processing is subjected to FFT transformation to obtain the effective signal matrix calculated in the jth cycle, and the original channel estimation matrix is subtracted from the effective signal matrix calculated in the jth cycle to obtain the effective signal matrix calculated in the jth cycle The second interference matrix; the second interference matrix calculated in the jth cycle includes the interference signal vectors of all subcarriers, denote

Is the interference signal vector of the i-th subcarrier.

Wherein, constructing the first interference matrix of the i-th subcarrier calculated in the j-th cycle according to the second interference matrix calculated in the j-th cycle includes:

The interference signal vector of the i-th subcarrier, the interference signal vector of the i-th subcarrier to the left of the _i- th subcarrier, and the interference signal vector of the i-th subcarrier in the second interference matrix calculated in the jth cycle The interference signal vectors of the _Ni sub-carriers on the right are spliced into the third interference matrix of the i-th sub-carrier calculated in the j-th cycle, namely

N _i is an integer greater than or equal to 0;

among them,

Is the interference vector of the (i-N _i )th subcarrier,

Is the interference vector of the (i+N _i )th subcarrier.

Where, N _i values can be dynamically selected according to the original channel estimation with interference signal power of the i th sub-carrier signal power to interference matrix or the calculation cycle j. When N _{i is} relatively large, the subspace dimension of the first interference matrix of the i-th sub-carrier calculated in the j-th cycle is larger, and the orthogonal projection can eliminate more interference components, and at the same time, there are more components that may eliminate the signal. In the high interference signal power scene, the positive gain of eliminating interference is greater than the negative gain of eliminating signal, and there is overall gain, but in the case of low interference signal power, the positive gain of eliminating interference is less than the negative gain of eliminating signal, and there is overall negative gain. When the N _{i is} relatively small, the orthogonal projection eliminates less interference components, and at the same time eliminates the signal components. The gain is small in the high interference power scene, but in the low interference rate scene there is small gain and no Negative gain. Therefore, in principle N _i is selected to select a large value in a high interference signal power condition, to obtain a large gain, the interference signal power at a low, select a smaller gain value obtained while avoiding small N _i Larger brings negative gain. That is, for the i th subcarrier, the interference signal power corresponding to the high value of N _i N _i is greater than the value corresponding to the low-interference signal power.

The Ni corresponding to different subcarriers may be the same or different.

Wherein, the calculation method of the interference signal power of the original channel estimation matrix is the same as the calculation method described in the following or the foregoing embodiment, and will not be repeated here.

The interference signal power of the i-th subcarrier calculated in the jth cycle can also be calculated in a similar way.

Step 203: Perform interference reduction processing on the original channel estimation vector corresponding to the i-th subcarrier in the original channel estimation matrix according to the first interference matrix of the i-th subcarrier calculated in the jth cycle to obtain the jth cycle The interference-reduced channel estimation vector of the i-th subcarrier is calculated, and the interference-reduced channel estimation vectors of all subcarriers calculated in the jth cycle constitute the interference-reduced channel estimation matrix calculated in the jth cycle.

In the embodiment of the present invention, interference reduction processing is performed on the original channel estimation vector corresponding to the i-th sub-carrier in the original channel estimation matrix according to the first interference matrix of the i-th sub-carrier calculated in the j-th cycle. The interference-reduced channel estimation vector of the i-th subcarrier calculated in the jth cycle includes:

Calculating the projection matrix of the i-th sub-carrier calculated in the j-th cycle according to the first interference matrix of the i-th sub-carrier calculated in the j-th cycle;

Project the original channel estimation vector corresponding to the i-th sub-carrier according to the projection matrix of the i-th sub-carrier calculated in the j-th cycle to obtain the interference-reduced channel of the i-th sub-carrier calculated in the j-th cycle Estimate the vector.

In the embodiment of the present invention, the calculation of the projection matrix of the i-th sub-carrier calculated in the j-th cycle according to the first interference matrix of the i-th sub-carrier calculated in the j-th cycle includes:

Perform singular value decomposition on the first interference matrix of the i-th subcarrier calculated in the jth cycle, and calculate the matrix according to the first K columns of the left singular matrix of the i-th subcarrier calculated in the jth cycle The projection matrix of the i-th subcarrier calculated in the jth cycle; where K is the number of singular values exceeding the singular value threshold.

In some embodiments, when N _{i is} greater than 0, the singular value decomposition is performed on the third interference matrix H _I1i of the i-th subcarrier calculated in the j-th cycle, that is

Among them, U _Ii is the left singular matrix of the i-th subcarrier, Λ _Ii is a diagonal matrix composed of singular values of the i-th subcarrier, and V _Ii is the right singular matrix of the i-th subcarrier. Set a threshold of singular value, consider that all the left singular vectors corresponding to the singular value larger than the threshold on the diagonal of Λ _Ii are the main feature vectors of interference, that is, the first K columns of U _Ii , (K is the number of singular values exceeding the threshold ) As the first interference matrix H _I2i calculated in the jth cycle.

In the embodiment of the present invention, the calculation of the projection matrix P _i of the i-th subcarrier calculated in the j-th cycle can be performed according to the formula of orthogonal projection, and the formula of orthogonal projection is as follows.

Wherein, P _i j is the cycle of calculation of the i-th subcarrier of the projection matrix, H _I2i said first interference matrix calculation cycle j th subcarrier of the i-th or j-th cycle comprises the calculation The matrix of the first K columns of the left singular matrix of the i-th subcarrier.

In the embodiment of the present invention, the original channel estimation vector H _LSi corresponding to the i-th subcarrier in the original channel estimation matrix is projected to obtain the original channel estimation vector corresponding to the i-th subcarrier after the projection calculated in the jth cycle, namely The interference-reduced channel estimation vector of the i-th subcarrier calculated for the jth cycle.

Among them, H _LSNewi is the interference-reduced channel estimation vector of the i-th subcarrier calculated in the jth cycle, H _LSi is the original channel estimation vector corresponding to the i-th subcarrier in the original channel estimation matrix, and P _i is the jth cycle The calculated projection matrix of the i-th subcarrier.

The embodiment of the present invention effectively removes the interference of the original channel estimation matrix based on the projection matrix, improves the channel estimation accuracy of the pilot, thereby directly or indirectly improving the cell throughput rate, and increases the step of loop iteration, multiple loops After iteration, the interference estimation is more accurate, thereby improving the effect of interference cancellation.

In another embodiment of the present invention, the method further includes:

Step 204: Determine the final channel estimation matrix according to the effective signal power changes of the interference reduction channel estimation matrix and the original channel estimation matrix calculated in the Mth cycle.

In the embodiment of the present invention, determining the final channel estimation matrix according to the effective signal power changes of the interference-reduced channel estimation matrix and the original channel estimation matrix calculated in the Mth cycle includes at least one of the following:

When the ratio of the effective signal power of the channel estimation matrix after interference reduction calculated in the M-th cycle to the effective signal power of the original channel estimation matrix is less than the first preset threshold, the final channel estimation matrix is determined to be the original channel estimation matrix;

When the ratio of the effective signal power of the channel estimation matrix after interference reduction calculated in the Mth cycle to the effective signal power of the original channel estimation matrix is greater than a first preset threshold, it is determined that the final channel estimation matrix is the first The interference reduction channel estimation matrix calculated in M cycles.

Among them, the effective signal power of the channel estimation matrix after interference reduction calculated in the Mth cycle can be calculated in the following manner:

Transform the interference-reduced channel estimation matrix calculated in the M-th cycle to the time domain to obtain the interference-reduced channel estimation matrix calculated in the M-th cycle of the time domain; for the interference-reduced channel calculated in the M-th cycle of the time domain The channel estimation vector after interference reduction corresponding to each antenna in the channel estimation matrix, and the power of the signal in the window of the noise window of the channel estimation vector after interference reduction corresponding to the antenna is calculated as the effective signal power of the antenna; The average value of the signal power minus the noise power in the converted window is used as the effective signal power of the channel estimation matrix after interference reduction calculated in the Mth cycle.

The embodiment of the present invention determines the final channel estimation matrix based on the effective signal power changes before and after interference cancellation calculated in M cycles, which ensures the robustness of the interference cancellation effect, and filters out negative gains caused by spatially high correlation scenarios.

In another embodiment of the present invention, the method further includes:

When the original channel estimation matrix meets the requirements for interference cancellation, the first cycle of calculation is continued.

Determine the first correlation between the interference signal power, the signal-to-noise ratio, the interference signal vector and the effective signal vector of the original channel estimation matrix;

(1) Interference signal power

For example, remember the original channel estimation matrix as

N _T represents the time length, N _T = N _RE.

(2) Signal to noise ratio

For example, remember the original channel estimation matrix as

N _T represents the time length, N _T = N _RE.

Perform the first preprocessing on the original channel estimation matrix in the time domain, and transform the channel estimation matrix after the first preprocessing into the frequency domain to obtain the second interference matrix calculated in the first cycle, denoted as

The value of all antennas corresponding to each subcarrier in the second interference matrix calculated in the first cycle is used as the interference signal vector of the subcarrier.

Wherein, the performing the first preprocessing on the original channel estimation matrix in the time domain includes: for the original channel estimation vector corresponding to each antenna in the original channel estimation matrix in the time domain, calculating the noise of the original channel estimation vector corresponding to the antenna The signal inside the window is set to zero, and the signal outside the noise window remains.

Perform a second preprocessing on the original channel estimation matrix in the time domain, and transform the channel estimation matrix after the second preprocessing into the frequency domain to obtain an effective signal matrix, which is recorded as

Wherein, the second preprocessing of the original channel estimation matrix in the time domain includes: for the original channel estimation vector corresponding to each antenna in the original channel estimation matrix in the time domain, the noise of the original channel estimation vector corresponding to the antenna The signal inside the window is retained, and the signal outside the noise window is set to zero.

Referring to FIG. 3, another embodiment of the present invention provides a channel estimation device, including:

The first construction module 301 is configured to construct the first interference matrix of the i-th sub-carrier according to the original channel estimation matrix; where i is an integer between 1 and N _RE , and N _RE is the number of sub-carriers;

The first interference reduction processing module 302 is configured to perform interference reduction processing on the original channel estimation vector corresponding to the i-th sub-carrier in the original channel estimation matrix according to the first interference matrix of the i-th sub-carrier to obtain the i-th sub-carrier The interference-reduced channel estimation vectors of all subcarriers form the interference-reduced channel estimation matrix.

In another embodiment of the present invention, it further includes:

The first channel estimation matrix determining module 303 is configured to determine the final channel estimation matrix according to the channel estimation matrix after interference reduction and the effective signal power change of the original channel estimation matrix.

In the embodiment of the present invention, the first channel estimation matrix determining module 303 is specifically configured to perform at least one of the following:

When the ratio of the effective signal power of the reduced interference channel estimation matrix to the effective signal power of the original channel estimation matrix is less than a first preset threshold, determining that the final channel estimation matrix is the original channel estimation matrix;

When the ratio of the effective signal power of the channel estimation matrix after interference reduction to the effective signal power of the original channel estimation matrix is greater than a first preset threshold, determine that the final channel estimation matrix is the channel after interference reduction Estimate the matrix.

In another embodiment of the present invention, it further includes:

The first judgment module 304 is used to judge whether the original channel estimation matrix meets the requirements for interference cancellation, and send the judgment result to the first construction module 301;

The first construction module 301 is specifically configured to: when the judgment result is that the original channel estimation matrix meets the requirements for interference cancellation, continue to perform the step of constructing the first interference matrix of the i-th subcarrier according to the original channel estimation matrix.

In the embodiment of the present invention, the first judgment module 304 is specifically configured to:

In the embodiment of the present invention, the first judgment module 304 is specifically configured to determine the interference signal power and the signal-to-noise ratio of the original channel estimation matrix in the following manner:

For the original channel estimation vector corresponding to each antenna in the original channel estimation matrix in the time domain, calculate the power of the signal outside the window of the noise window of the original channel estimation vector corresponding to the antenna as the interference signal power of the antenna; calculate the antenna The power of the signal in the noise window of the corresponding original channel estimation vector is used as the effective signal power of the antenna;

The average value of the interference signal power of all antennas is used as the interference signal power of the original channel estimation matrix, and the average value of the effective signal power of all antennas minus the noise power in the converted window is used as the effective signal of the original channel estimation matrix power;

In the embodiment of the present invention, the first judgment module 304 is specifically configured to determine the first correlation between the interference signal vector and the effective signal vector of the original channel estimation matrix in the following manner:

Perform a first preprocessing on the original channel estimation matrix in the time domain, transform the channel estimation matrix after the first preprocessing into the frequency domain to obtain the second interference matrix; assign each subcarrier in the second interference matrix to The values of all antennas are used as the interference signal vector of the subcarrier;

Perform a second preprocessing on the original channel estimation matrix in the time domain, transform the channel estimation matrix after the second preprocessing into the frequency domain to obtain an effective signal matrix; convert the values of all antennas corresponding to each subcarrier in the effective signal matrix As the effective signal vector of the subcarrier;

For each subcarrier, calculate the second correlation between the interference signal vector corresponding to the subcarrier and the effective signal vector, and use the average of the second correlations corresponding to all subcarriers as the interference signal vector and the effective signal vector The first correlation between.

In the embodiment of the present invention, the first construction module 301 is specifically configured to construct the first interference matrix of the i-th subcarrier according to the original channel estimation matrix in the following manner:

Determining a second interference matrix according to the original channel estimation matrix;

In the embodiment of the present invention, the first construction module 301 is specifically configured to determine the second interference matrix according to the original channel estimation matrix in the following manner:

In the embodiment of the present invention, the first construction module 301 is specifically configured to construct the first interference matrix of the i-th subcarrier according to the second interference matrix in the following manner:

In the second interference matrix, the interference signal vector of the i-th subcarrier, the interference signal vector of the Ni subcarriers to the left of the _i- th subcarrier, and the interference of the Ni subcarriers to the right of the _i- th subcarrier The signal vector is spliced into the first interference matrix of the i-th subcarrier; N _i is an integer greater than or equal to 0.

Wherein, for the i-th sub-carrier, high-power interference signal corresponding to the value of N _i N _i is greater than the value corresponding to the low-interference signal power.

In the embodiment of the present invention, the first construction module 301 is specifically configured to implement the corresponding original channel estimation of the i-th sub-carrier in the original channel estimation matrix according to the first interference matrix of the i-th sub-carrier in the following manner The vector performs interference reduction processing to obtain the interference-reduced channel estimation vector of the i-th subcarrier:

In the embodiment of the present invention, the first construction module 301 is specifically configured to calculate the projection matrix of the i-th sub-carrier according to the first interference matrix of the i-th sub-carrier in the following manner:

In the embodiment of the present invention, the first construction module 301 is specifically configured to calculate the projection matrix of the i-th subcarrier in the following manner:

According to the formula

Calculating the projection matrix of the i-th subcarrier;

In the embodiment of the present invention, the first interference reduction processing module 302 is specifically configured to implement the original channel estimation corresponding to the i-th sub-carrier in the original channel estimation matrix according to the projection matrix of the i-th sub-carrier in the following manner The vector is projected to obtain the interference-reduced channel estimation vector of the i-th subcarrier:

According to the formula

Calculating the interference-reduced channel estimation vector of the i-th subcarrier;

Where H _LSNewi is the interference-reduced channel estimation vector of the i-th subcarrier, H _LSi is the original channel estimation vector corresponding to the i-th subcarrier in the original channel estimation matrix, and P _i is the i-th subcarrier The projection matrix.

The specific implementation process of the foregoing channel estimation device is the same as the specific implementation process of the channel estimation method in the foregoing embodiment, and will not be repeated here.

Referring to FIG. 4, another embodiment of the present invention provides a channel estimation device, including:

The second construction module 401, in the first round calculation, constructs the first interference matrix of the i-th subcarrier calculated in the first round constructed according to the original channel estimation matrix; where i is an integer between 1 and N _RE , N _RE is the number of subcarriers; in the j-th cyclic calculation, the i-th cyclic calculation of the jth cyclic calculation is constructed according to the original channel estimation matrix and the interference-reduced channel estimation matrix calculated in the (j-1)th cyclic calculation The first interference matrix of sub-carriers; where j is an integer between 2 and M, and M is the maximum number of iterations;

The second interference reduction processing module 402 is configured to reduce the original channel estimation vector corresponding to the i-th sub-carrier in the original channel estimation matrix according to the first interference matrix of the i-th sub-carrier calculated in the first cycle. Interference processing obtains the interference-reduced channel estimation vector of the i-th subcarrier calculated in the first cycle, and the interference-reduced channel estimation vector of all subcarriers calculated in the first cycle constitutes the interference-reduced channel estimation vector calculated in the first cycle Channel estimation matrix; performing interference reduction processing on the original channel estimation vector corresponding to the i-th sub-carrier in the original channel estimation matrix according to the first interference matrix of the i-th sub-carrier calculated in the j-th cycle to obtain the j-th time The interference-reduced channel estimation vector of the i-th subcarrier calculated cyclically, and the interference-reduced channel estimation vectors of all subcarriers calculated in the jth cycle constitute the interference-reduced channel estimation matrix calculated in the jth cycle.

In another embodiment of the present invention, it further includes:

The second channel estimation matrix determining module 403 is configured to determine the final channel estimation matrix according to the channel estimation matrix after interference reduction calculated in the M-th cycle and the effective signal power change of the original channel estimation matrix.

In the embodiment of the present invention, the second channel estimation matrix determining module 403 is specifically configured to perform at least one of the following:

In another embodiment of the present invention, it further includes:

The second judgment module 404 is configured to judge whether the original channel estimation matrix meets the requirements for interference cancellation, and send the judgment result to the second construction module 401;

The second construction module 401 is further configured to: when the judgment result is that the original channel estimation matrix meets the requirements for interference cancellation, continue the first round of calculation.

In the embodiment of the present invention, the second judgment module 404 is specifically configured to use the following methods to determine whether the original channel estimation matrix meets the requirements for interference cancellation:

In the embodiment of the present invention, the second judgment module 404 is specifically configured to determine the interference signal power and the signal-to-noise ratio of the original channel estimation matrix in the following manner:

In the embodiment of the present invention, the second judgment module 404 is specifically configured to determine the first correlation between the interference signal vector and the effective signal vector of the original channel estimation matrix in the following manner:

Perform the first preprocessing on the original channel estimation matrix in the time domain, transform the channel estimation matrix after the first preprocessing into the frequency domain to obtain the second interference matrix; all the antennas corresponding to each subcarrier in the second interference matrix The value of is used as the interference signal vector of the subcarrier;

Perform the second preprocessing on the original channel estimation matrix in the time domain, transform the channel estimation matrix after the second preprocessing into the frequency domain to obtain the effective signal matrix; use the values of all antennas corresponding to each subcarrier in the effective signal matrix as the The effective signal vector of the subcarrier;

In the embodiment of the present invention, the second construction module 401 is specifically configured to use the following methods to implement the construction of the jth cycle calculation based on the original channel estimation matrix and the interference-reduced channel estimation matrix calculated in the (j-1)th cycle: The first interference matrix of i subcarriers:

Determine the second interference matrix calculated in the jth cycle according to the original channel estimation matrix calculated in the jth cycle;

In the embodiment of the present invention, the second construction module 401 is specifically configured to use the following method to determine the jth cyclic calculation based on the original channel estimation matrix and the interference-reduced channel estimation matrix calculated in the (j-1)th cycle: Two interference matrix:

Calculating the second interference matrix calculated in the jth cycle according to the original channel estimation matrix and the effective signal matrix calculated in the jth cycle;

In the embodiment of the present invention, the second construction module 401 is specifically configured to construct the first interference matrix of the i-th subcarrier calculated in the jth cycle according to the second interference matrix calculated in the jth cycle in the following manner:

The interference signal vector of the i-th subcarrier, the interference signal vector of the i-th subcarrier on the left side of the _i- th subcarrier, and the right side of the i-th subcarrier in the second interference matrix calculated in the jth cycle The interference signal vectors of the _Ni sub-carriers are spliced into the first interference matrix of the i-th sub-carrier calculated in the j-th cycle; N _i is an integer greater than or equal to 0.

In the embodiment of the present invention, the second construction module 401 is specifically configured to use the following method to implement the first interference matrix of the i-th sub-carrier calculated according to the j-th cycle to the i-th sub-carrier in the original channel estimation matrix: Perform interference reduction processing on the corresponding original channel estimation vector to obtain the interference-reduced channel estimation vector of the i-th subcarrier calculated in the jth cycle:

In the embodiment of the present invention, the second construction module 401 is specifically configured to use the following method to calculate the projection of the i-th sub-carrier calculated in the j-th cycle according to the first interference matrix of the i-th sub-carrier calculated in the j-th cycle matrix:

In the embodiment of the present invention, the second construction module 401 is specifically configured to calculate the projection matrix of the i-th subcarrier calculated in the j-th cycle in the following manner:

According to the formula

Calculating the projection matrix of the i-th subcarrier calculated in the j-th cycle;

In the embodiment of the present invention, the second interference reduction processing module 402 is specifically configured to implement the correspondence between the projection matrix of the i-th sub-carrier calculated according to the j-th cycle and the i-th sub-carrier in the original channel estimation matrix in the following manner: The original channel estimation vector of is projected to obtain the interference-reduced channel estimation vector of the i-th subcarrier calculated in the jth cycle:

According to the formula

Calculating the interference-reduced channel estimation vector of the i-th subcarrier calculated in the jth cycle;

Where, H _LSNewi is the interference-reduced channel estimation vector of the i-th subcarrier calculated in the jth cycle, H _LSi is the original channel estimation vector corresponding to the i-th subcarrier in the original channel estimation matrix, and P _i is the The projection matrix of the i-th subcarrier calculated in the jth cycle

Another embodiment of the present invention provides a channel estimation device, including a processor and a computer-readable storage medium, the computer-readable storage medium stores instructions, and when the instructions are executed by the processor, the foregoing Any channel estimation method.

Another embodiment of the present invention provides a computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, the steps of any of the foregoing channel estimation methods are implemented.

The embodiment of the present invention includes: a first interference matrix of the i-th sub-carrier constructed according to the original channel estimation matrix; wherein i is an integer between 1 and N _RE , and N _RE is the number of sub-carriers; according to the i-th sub-carrier The first interference matrix in the original channel estimation matrix performs interference reduction processing on the original channel estimation vector corresponding to the i-th subcarrier in the original channel estimation matrix to obtain the interference-reduced channel estimation vector of the i-th subcarrier. The channel estimation vector of, constitutes the channel estimation matrix after interference reduction. The embodiment of the present invention effectively removes the interference of the original channel estimation matrix based on the first interference matrix, improves the accuracy of the pilot channel estimation, and directly or indirectly improves the cell throughput.

In another exemplary embodiment, the final channel estimation matrix is determined according to the channel estimation matrix after interference reduction and the effective signal power change of the original channel estimation matrix. The embodiment of the present invention determines the final channel estimation matrix based on the change of the effective signal power before and after the interference is eliminated, which ensures the robustness of the interference elimination effect and filters out the negative gain brought by the spatially high correlation scene.

In another exemplary embodiment, when the original channel estimation matrix meets the requirement for interference cancellation, the step of constructing the first interference matrix of the i-th subcarrier according to the original channel estimation matrix is continued. In the embodiment of the present invention, interference cancellation is performed only when the original channel estimation matrix meets the requirements for interference cancellation, and the negative gain caused by scenarios that do not meet the interference cancellation requirements is filtered out, which further improves the accuracy of pilot channel estimation, thereby directly Or indirectly increase the cell throughput rate.

Another embodiment of the present invention includes: in the first round of calculation, the first interference matrix of the i-th subcarrier calculated in the first round constructed according to the original channel estimation matrix; where i is a value between 1 and N _RE Integer, N _RE is the number of sub-carriers; the first interference matrix of the i-th sub-carrier calculated in the first cycle reduces the interference on the original channel estimation vector corresponding to the i-th sub-carrier in the original channel estimation matrix The interference-reduced channel estimation vector of the i-th subcarrier calculated in the first cycle is processed, and the interference-reduced channel estimation vector of all subcarriers calculated in the first cycle constitutes the interference-reduced channel calculated in the first cycle Estimation matrix; in the j-th cycle calculation, the i-th sub-carrier calculated in the j-th cycle calculated according to the original channel estimation matrix and the channel estimation matrix after interference reduction calculated in the (j-1)-th cycle An interference matrix; where j is an integer between 2 and M, and M is the maximum number of iterations; the first interference matrix of the i-th sub-carrier calculated according to the j-th cycle compares the first interference matrix in the original channel estimation matrix The corresponding original channel estimation vectors of i subcarriers are processed to reduce interference to obtain the interference reduced channel estimation vectors of the i-th subcarrier calculated in the jth cycle, and the interference reduced channel estimates of all subcarriers calculated in the jth cycle The vector constitutes the channel estimation matrix after interference reduction calculated in the jth cycle. The embodiment of the present invention effectively removes the interference of the original channel estimation matrix based on the projection matrix, improves the channel estimation accuracy of the pilot, thereby directly or indirectly improving the cell throughput rate, and increases the step of loop iteration, multiple loops After iteration, the interference estimation is more accurate, thereby improving the effect of interference cancellation.

A person of ordinary skill in the art can understand that all or some of the steps, functional modules/units in the system, and apparatus in the methods disclosed above can be implemented as software, firmware, hardware, and appropriate combinations thereof. In hardware implementations, the division between functional modules/units mentioned in the above description does not necessarily correspond to the division of physical components; for example, one physical component may have multiple functions, or one function or step may consist of several physical components. The components are executed cooperatively. Some or all components may be implemented as software executed by a processor, such as a digital signal processor or a microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on a computer-readable medium, and the computer-readable medium may include a computer storage medium (or non-transitory medium) and a communication medium (or transitory medium). As is well known to those of ordinary skill in the art, the term computer storage medium includes volatile and non-volatile memory implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Flexible, removable and non-removable media. Computer storage media include but are not limited to RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disk (DVD) or other optical disk storage, magnetic cassette, tape, magnetic disk storage or other magnetic storage device, or Any other medium used to store desired information and that can be accessed by a computer. In addition, as is well known to those of ordinary skill in the art, communication media usually contain computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as carrier waves or other transmission mechanisms, and may include any information delivery media .

Although the implementation manners disclosed in the embodiments of the present invention are as described above, the content described is only the implementation manners used to facilitate the understanding of the embodiments of the present invention, and is not intended to limit the embodiments of the present invention. Any person skilled in the art of the embodiment of the present invention can make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed by the embodiment of the present invention. The scope of patent protection shall still be subject to the scope defined by the appended claims.

Claims

A channel estimation method, including:

The first interference matrix of the i-th subcarrier constructed according to the original channel estimation matrix; where i is an integer between 1 and N RE , and N RE is the number of subcarriers;

According to the first interference matrix of the i-th subcarrier, perform interference reduction processing on the original channel estimation vector corresponding to the i-th subcarrier in the original channel estimation matrix to obtain the interference-reduced channel estimation vector of the i-th subcarrier. The interference-reduced channel estimation vector of the subcarriers constitutes the interference-reduced channel estimation matrix.
The method according to claim 1, wherein the method further comprises:

The final channel estimation matrix is determined according to the channel estimation matrix after interference reduction and the effective signal power change of the original channel estimation matrix.
The method according to claim 2, wherein the determining the final channel estimation matrix according to the effective signal power change of the channel estimation matrix after interference reduction and the original channel estimation matrix comprises at least one of the following:

When the ratio of the effective signal power of the reduced interference channel estimation matrix to the effective signal power of the original channel estimation matrix is less than a first preset threshold, determining that the final channel estimation matrix is the original channel estimation matrix;

When the ratio of the effective signal power of the channel estimation matrix after interference reduction to the effective signal power of the original channel estimation matrix is greater than a first preset threshold, determine that the final channel estimation matrix is the channel after interference reduction Estimate the matrix.
The method according to claim 1 or 2, wherein the method further comprises:

When the original channel estimation matrix meets the requirements for interference cancellation, continue to perform the step of calculating the first interference matrix of the i-th subcarrier according to the original channel estimation matrix.
The method according to claim 4, wherein determining whether the original channel estimation matrix meets the requirements for interference cancellation includes:

Determining the first correlation between the interference signal power, the signal-to-noise ratio, the interference signal vector, and the effective signal vector of the original channel estimation matrix;

According to the interference signal power, the signal-to-noise ratio, the first correlation between the interference signal vector and the effective signal vector, it is determined whether the original channel estimation matrix meets the requirements for interference cancellation.
The method according to claim 5, wherein the determining the interference signal power and the signal-to-noise ratio of the original channel estimation matrix comprises:

Transform the original channel estimation matrix into the time domain to obtain the original channel estimation matrix in the time domain;

For the original channel estimation vector corresponding to each antenna in the original channel estimation matrix in the time domain, calculate the power of the signal outside the window of the noise window of the original channel estimation vector corresponding to the antenna as the interference signal power of the antenna; calculate the antenna The power of the signal in the noise window of the corresponding original channel estimation vector is used as the effective signal power of the antenna;

The average value of the interference signal power of all antennas is used as the interference signal power of the original channel estimation matrix, and the average value of the effective signal power of all antennas minus the noise power in the converted window is used as the effective signal of the original channel estimation matrix power;

The signal-to-noise ratio is calculated according to the interference signal power of the original channel estimation matrix and the effective signal power of the original channel estimation matrix.
The method according to claim 5, wherein said determining the first correlation between the interference signal vector and the effective signal vector of the original channel estimation matrix comprises:

Perform a first preprocessing on the original channel estimation matrix in the time domain, transform the channel estimation matrix after the first preprocessing into the frequency domain to obtain the second interference matrix; assign each subcarrier in the second interference matrix to The values of all antennas are used as the interference signal vector of the subcarrier;

Perform a second preprocessing on the original channel estimation matrix in the time domain, transform the channel estimation matrix after the second preprocessing into the frequency domain to obtain an effective signal matrix; convert the values of all antennas corresponding to each subcarrier in the effective signal matrix As the effective signal vector of the subcarrier;

For each subcarrier, calculate the second correlation between the interference signal vector corresponding to the subcarrier and the effective signal vector, and use the average of the second correlations corresponding to all subcarriers as the interference signal vector and the effective signal vector The first correlation between.
The method according to claim 1 or 2, wherein the first interference matrix of the i-th subcarrier constructed according to the original channel estimation matrix comprises:

Determining a second interference matrix according to the original channel estimation matrix;

The first interference matrix of the i-th subcarrier is constructed according to the second interference matrix.
The method according to claim 8, wherein the determining the second interference matrix according to the original channel estimation matrix comprises:

Transform the original channel estimation matrix into the time domain to obtain the original channel estimation matrix in the time domain;

Performing first preprocessing on the original channel estimation matrix in the time domain, and transforming the channel estimation matrix after the first preprocessing into the frequency domain to obtain the second interference matrix;

Wherein, the performing the first preprocessing on the original channel estimation matrix in the time domain includes: for the original channel estimation vector corresponding to each antenna in the original channel estimation matrix in the time domain, calculating the original channel estimation vector corresponding to the antenna The signal inside the window of the noise window is set to zero, and the signal outside the window of the noise window remains.
The method according to claim 8, wherein the constructing the first interference matrix of the i-th subcarrier according to the second interference matrix comprises:

In the second interference matrix, the interference signal vector of the i-th subcarrier, the interference signal vector of the Ni subcarriers to the left of the i- th subcarrier, and the interference of the Ni subcarriers to the right of the i- th subcarrier The signal vector is spliced into the first interference matrix of the i-th subcarrier; N i is an integer greater than or equal to 0.
The method according to claim 10, wherein, for the i-th sub-carrier, high-power interference signal corresponding to the value of N i N i is greater than the value corresponding to the low-interference signal power.
The method according to claim 1 or 2, wherein the interference reduction is performed on the original channel estimation vector corresponding to the i-th sub-carrier in the original channel estimation matrix according to the first interference matrix of the i-th sub-carrier The channel estimation vector after interference reduction of the i-th subcarrier obtained by processing includes:

Calculating the projection matrix of the i-th sub-carrier according to the first interference matrix of the i-th sub-carrier;

Projecting the original channel estimation vector corresponding to the i-th sub-carrier according to the projection matrix of the i-th sub-carrier to obtain the interference-reduced channel estimation vector of the i-th sub-carrier.
The method according to claim 12, wherein the calculating the projection matrix of the i-th sub-carrier according to the first interference matrix of the i-th sub-carrier comprises:

Perform singular value decomposition on the first interference matrix of the i-th subcarrier, and calculate the projection matrix of the i-th subcarrier according to the matrix containing the first K columns of the left singular matrix of the i-th subcarrier; where K is The number of singular values exceeding the singular value threshold. 14. A channel estimation method, including:

In the first round of calculation, the first interference matrix of the i-th subcarrier calculated in the first round constructed from the original channel estimation matrix; where i is an integer between 1 and N RE , and N RE is the number of subcarriers ；

Perform interference reduction processing on the original channel estimation vector corresponding to the i-th sub-carrier in the original channel estimation matrix according to the first interference matrix of the i-th subcarrier calculated in the first cycle to obtain the first interference matrix calculated in the first cycle. The interference-reduced channel estimation vectors of i subcarriers, and the interference-reduced channel estimation vectors of all subcarriers calculated in the first cycle constitute the interference-reduced channel estimation matrix calculated in the first cycle;

In the j-th cycle calculation, the first interference matrix of the i-th subcarrier calculated in the j-th cycle constructed based on the original channel estimation matrix and the channel estimation matrix after interference reduction calculated in the (j-1)th cycle ; Among them, j is an integer between 2 and M, and M is the maximum number of iterations;

Perform interference reduction processing on the original channel estimation vector corresponding to the i-th sub-carrier in the original channel estimation matrix according to the first interference matrix of the i-th sub-carrier calculated in the j-th cycle to obtain the first interference matrix calculated in the j-th cycle The interference-reduced channel estimation vectors of i subcarriers, and the interference-reduced channel estimation vectors of all subcarriers calculated in the jth cycle constitute the interference-reduced channel estimation matrix calculated in the jth cycle.
The method according to claim 14, wherein the method further comprises:

The final channel estimation matrix is determined according to the channel estimation matrix after interference reduction calculated in the Mth cycle and the effective signal power change of the original channel estimation matrix.
The method according to claim 15, wherein the determination of the final channel estimation matrix according to the effective signal power changes of the reduced interference channel estimation matrix and the original channel estimation matrix calculated in the Mth cycle comprises at least one of the following:

When the ratio of the effective signal power of the interference-reduced channel estimation matrix calculated in the M-th cycle to the effective signal power of the original channel estimation matrix is less than a first preset threshold, it is determined that the final channel estimation matrix is The original channel estimation matrix;

When the ratio of the effective signal power of the interference-reduced channel estimation matrix calculated in the Mth cycle to the effective signal power of the original channel estimation matrix is greater than a first preset threshold, it is determined that the final channel estimation matrix is The channel estimation matrix after interference reduction calculated in the Mth cycle.
The method according to claim 14 or 15, wherein the method further comprises:

When the original channel estimation matrix meets the requirement for interference cancellation, continue the first round of calculation.
The method according to claim 17, wherein determining whether the original channel estimation matrix meets the requirements for interference cancellation comprises:

Determining the first correlation between the interference signal power, the signal-to-noise ratio, the interference signal vector, and the effective signal vector of the original channel estimation matrix;

According to the interference signal power, the signal-to-noise ratio, the first correlation between the interference signal vector and the effective signal vector, it is determined whether the original channel estimation matrix meets the requirements for interference cancellation.
The method according to claim 14 or 15, wherein the i-th subcarrier calculated in the j-th cycle constructed based on the original channel estimation matrix and the interference-reduced channel estimation matrix calculated in the (j-1)-th cycle The first interference matrix includes:

Determine the second interference matrix calculated in the jth cycle according to the original channel estimation matrix and the channel estimation matrix after interference reduction calculated in the (j-1)th cycle;

Construct the first interference matrix of the i-th subcarrier calculated in the j-th cycle according to the second interference matrix calculated in the j-th cycle.
The method according to claim 19, wherein the determining the second interference matrix calculated in the jth cycle according to the original channel estimation matrix and the channel estimation matrix after interference reduction calculated in the (j-1)th cycle comprises:

Transforming the interference-reduced channel estimation matrix calculated in the (j-1)th cycle into the time domain to obtain the interference-reduced channel estimation matrix calculated in the (j-1)th cycle in the time domain;

Perform a second preprocessing on the interference-reduced channel estimation matrix calculated in the (j-1)th cycle of the time domain, and transform the channel estimation matrix after the second preprocessing into the frequency domain to obtain the jth cycle Calculated effective signal matrix;

Calculating the second interference matrix calculated in the jth cycle according to the original channel estimation matrix and the effective signal matrix calculated in the jth cycle;

Wherein, the second preprocessing of the interference reduction channel estimation matrix calculated in the (j-1)th cycle of the time domain includes: the interference reduction calculated in the (j-1)th cycle of the time domain The original channel estimation vector corresponding to each antenna in the subsequent channel estimation matrix retains the signal within the noise window of the original channel estimation vector corresponding to the antenna, and zeros the signal outside the noise window.
The method according to claim 20, wherein the constructing the first interference matrix of the i-th subcarrier calculated in the j-th cycle according to the second interference matrix calculated in the j-th cycle comprises:

The interference signal vector of the i-th subcarrier, the interference signal vector of the i-th subcarrier on the left side of the i- th subcarrier, and the right side of the i-th subcarrier in the second interference matrix calculated in the jth cycle The interference signal vectors of the Ni sub-carriers are spliced into the first interference matrix of the i-th sub-carrier calculated in the j-th cycle; N i is an integer greater than or equal to 0.
The method according to claim 14 or 15, wherein the first interference matrix of the i-th sub-carrier calculated according to the j-th cycle has an original corresponding to the i-th sub-carrier in the original channel estimation matrix The channel estimation vector performs interference reduction processing to obtain the interference-reduced channel estimation vector of the i-th subcarrier calculated in the jth cycle, including:

Calculating the projection matrix of the i-th sub-carrier calculated in the j-th cycle according to the first interference matrix of the i-th sub-carrier calculated in the j-th cycle;

Project the original channel estimation vector corresponding to the i-th sub-carrier according to the projection matrix of the i-th sub-carrier calculated in the j-th cycle to obtain the interference-reduced channel of the i-th sub-carrier calculated in the j-th cycle Estimate the vector.
The method according to claim 22, wherein the calculation of the projection matrix of the i-th sub-carrier calculated in the j-th cycle according to the first interference matrix of the i-th sub-carrier calculated in the j-th cycle comprises:

Perform singular value decomposition on the first interference matrix of the i-th subcarrier calculated in the jth cycle, and calculate the matrix according to the first K columns of the left singular matrix of the i-th subcarrier calculated in the jth cycle The projection matrix of the i-th subcarrier calculated in the jth cycle; where K is the number of singular values exceeding the singular value threshold.
A channel estimation device, comprising a processor and a computer-readable storage medium, the computer-readable storage medium stores instructions, wherein, when the instructions are executed by the processor, any of claims 1 to 23 are implemented. The channel estimation method described in one item.
A computer-readable storage medium having a computer program stored thereon, wherein the computer program implements the steps of the channel estimation method according to any one of claims 1 to 23 when the computer program is executed by a processor.