CN102647387B - The removing method of co-channel interference and device - Google Patents

Abstract

The embodiment of the present invention discloses a method and device for eliminating co-channel interference. The method includes: selecting at least two regions in the time-frequency domain; calculating the interference autocorrelation matrix of each region in the at least two regions; Interference autocorrelation matrices of regions After judging the presence of co-channel interference, an interference autocorrelation matrix is obtained from the interference autocorrelation matrices of at least two regions; interference cancellation is performed on received signals through the obtained interference autocorrelation matrices. In the embodiment of the present invention, since at least two regions are selected in the time-frequency domain to calculate the interference autocorrelation matrix, the current co-channel interference situation can be obtained by comparison, and the interference autocorrelation matrix can be selected according to the comparison result, which can improve The accuracy of the interference autocorrelation matrix, for received signals with different degrees of same-frequency interference, the appropriate interference autocorrelation matrix can be obtained by selecting, thereby reducing the error of interference elimination.

Description

Method and device for eliminating co-channel interference

technical field

The invention relates to the field of communication technology, in particular to a method and device for eliminating co-channel interference.

Background technique

In LTE (Long Term Evolution, Long Term Evolution) proposed by 3GPP, MIMO (Multiple-Input Multiple-Output, Multiple Input Multiple Output) technology and OFDM (Orthogonal Frequency Division Multiplexing, Orthogonal Frequency Division Multiplexing) technology are used for communication. When sending data in the downlink, different users in the same cell occupy different subcarriers to achieve multiple access, but users in adjacent cells may use the same frequency band for data transmission. At this time, co-frequency interference may occur between adjacent cells. Reduce the reliability of data communication.

In the prior art, in order to suppress co-channel interference between adjacent cells, an area can be first selected in the time-frequency domain. The time domain in the time-frequency domain contains several consecutive OFDM symbols, and the frequency domain contains consecutive OFDM symbols. several sub-carriers, and then calculate the interference autocorrelation matrix of all pilot points in the selected area, take the average value of all the above interference autocorrelation matrices as the estimated value of the interference autocorrelation matrix of all symbols in the area, through the autocorrelation The matrix estimates perform interference cancellation on the received signal.

If the area selected in the time-frequency domain is small, the number of samples of pilot points in the area is small, so the estimated value of the interference autocorrelation matrix calculated is not accurate enough; if the area selected in the time-frequency domain is large, then The value of the interference channel in this area will have a large change. At this time, if all received signals use the same interference autocorrelation matrix estimation value matrix to remove interference, there will be a large error.

Contents of the invention

Embodiments of the present invention provide a method and device for eliminating co-channel interference, so as to solve the problem of large error and inaccuracy in existing co-channel interference cancellation.

In order to solve the above technical problems, the embodiment of the present invention discloses the following technical solutions:

A method for eliminating co-channel interference, comprising:

Select at least two regions in the time-frequency domain;

calculating an interference autocorrelation matrix for each of the at least two regions;

After judging the existence of co-channel interference according to the interference autocorrelation matrix of each area, an interference autocorrelation matrix is obtained from the interference autocorrelation matrices of at least two areas;

Interference cancellation is performed on the received signal through the obtained interference autocorrelation matrix.

A device for eliminating co-channel interference, comprising:

a selection unit, configured to select at least two regions in the time-frequency domain;

a calculation unit for calculating an interference autocorrelation matrix for each of the at least two areas;

The acquisition unit is configured to obtain an interference autocorrelation matrix from the interference autocorrelation matrices of at least two areas after judging the existence of co-channel interference according to the interference autocorrelation matrix of each area;

The elimination unit is configured to perform interference elimination on the received signal by using the acquired interference autocorrelation matrix.

It can be seen from the above embodiments that the embodiment of the present invention selects at least two regions in the time-frequency domain, calculates the interference autocorrelation matrix of each region in the at least two regions, and judges the same frequency based on the interference autocorrelation matrix of each region. After the existence of interference, an interference autocorrelation matrix is obtained from the interference autocorrelation matrices of at least two regions, and interference cancellation is performed on the received signal through the obtained interference autocorrelation matrix. In the embodiment of the present invention, since at least two regions are selected in the time-frequency domain to calculate the interference autocorrelation matrix, the current co-channel interference situation can be obtained by comparison, and the interference autocorrelation matrix can be selected according to the comparison result, which can improve The accuracy of the interference autocorrelation matrix, for received signals with different degrees of same-frequency interference, the appropriate interference autocorrelation matrix can be obtained by selecting, thereby reducing the error of interference elimination.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, In other words, other drawings can also be obtained from these drawings without paying creative labor.

FIG. 1 is a schematic diagram of a communication architecture of a MIMO-based LTE system;

Fig. 2 is the flow chart of the first embodiment of the elimination method of co-channel interference of the present invention;

FIG. 3A is a flowchart of a second embodiment of the method for eliminating co-channel interference of the present invention;

FIG. 3B is a schematic diagram of a selected region in the time-frequency domain;

Fig. 4 is a schematic diagram of obtaining an interference autocorrelation matrix;

5 is a block diagram of an embodiment of a device for eliminating co-channel interference of the present invention;

Fig. 6 is a block diagram of an embodiment of a computing unit in Fig. 5;

Fig. 7 is a block diagram of an embodiment of the acquisition unit in Fig. 5;

FIG. 8 is a block diagram of an embodiment of the canceling unit in FIG. 5 .

Detailed ways

The following embodiments of the present invention provide a method and device for eliminating co-channel interference.

In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention, and to make the above-mentioned purposes, features and advantages of the embodiments of the present invention more obvious and understandable, the following describes the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings For further detailed explanation.

Before describing the embodiment of the present invention in detail, the communication system to which the embodiment of the present invention is applied is described first.

Referring to Figure 1, it is a schematic diagram of a communication architecture of a MIMO-based LTE system:

In Figure 1, both the transmitter and the receiver have multiple antennas. Assuming that the transmitter has T transmitting antennas and the receiver has R receiving antennas, the model of the signal received by the receiver can be expressed as the following formula:

Y=HX+U

In the above formula, X is the signal sequence transmitted by the transmitter, X=[x ₁ , x ₂ ,...x _T ] ^T , where x _i is the signal sent by the i-th antenna; the corresponding signal received by the receiver The vector is Y=[y ₁ , y ₂ , . . . y _R ] ^T . U=[u ₁ , u ₂ ,...u _R ] ^T , where U represents the sum of interference and noise from other base stations to the base station where the current receiver is located. H is an R×T dimensional channel matrix, which represents the channel characteristics of the channel through which the transmitted signal passes. When U's autocorrelation matrix R _uu =E(UU ^H ) is not a diagonal matrix, it means that there is co-channel interference in the received signal, and the received signal needs to be filtered to remove the correlation of the interference.

Referring to Fig. 2, it is the flow chart of the first embodiment of the elimination method of co-channel interference of the present invention:

Step 201: Select at least two regions in the time-frequency domain.

In the communication system, for each selected area, the time domain in the time-frequency domain contains several consecutive OFDM symbols, the frequency domain contains several consecutive subcarriers, and each area contains several receiving symbols in the time-frequency domain. The pilot point of the signal. In this embodiment, preferably, two regions are selected in the time-frequency domain, namely the first region and the second region, and the number of pilot points included in the two regions is different. The first area and the second area can be selected according to certain criteria combined with actual simulation results.

For example, a selection criterion is: the first area needs to ensure that the interference autocorrelation matrix estimated in the first area can determine whether there is co-channel interference. When the number of pilot points in the area is large, it is easier Judging that there is no co-channel interference, when the number of pilot points in the area is small, it is easier to judge that there is co-channel interference, so the specific value of the number of pilot points N1 contained in the first area can be combined with the simulation of the actual system Obtained, preferably, the number of pilot points N1=48 in the first area; the second area needs to ensure that the interference autocorrelation matrix estimated according to the second area can determine the speed of co-channel interference change, when the second The fewer the number of pilot points in the second area, the more it can reflect the change of co-channel interference, so the specific value of N2 in the second area is simulated in the actual system. Preferably, the pilot points in the second area The number N2=16.

Step 202: Calculate an interference autocorrelation matrix for each of the at least two regions.

Specifically, each pilot point in each area is obtained, the interference autocorrelation matrix of each pilot point in each area is calculated, and the interference autocorrelation matrix of all pilot points in each area is accumulated to obtain the accumulation result, and the The average of the accumulated results relative to at least two regions is used as an interference autocorrelation matrix for each region.

Step 203: After judging the presence of co-channel interference according to the interference autocorrelation matrix of each area, obtain an interference autocorrelation matrix from the interference autocorrelation matrices of at least two areas.

Still taking the example of selecting the first area and the second area in the time-frequency domain, wherein the number of pilot points in the first area is greater than the number of pilot points in the second area. Specifically, when it is judged that the first interference correlation coefficient calculated according to the first interference autocorrelation matrix in the first area is not greater than the preset first threshold, it is determined that there is no co-channel interference in the received signal, and the first interference autocorrelation matrix Set the non-main line elements of the zero-setting first interference autocorrelation matrix as the obtained interference autocorrelation matrix; when judging the second interference correlation calculated according to the second interference autocorrelation matrix of the second area When the coefficient is not less than the preset second threshold, it is determined that there is co-channel interference in the received signal, and the second interference autocorrelation matrix is used as the obtained interference autocorrelation matrix; when it is judged that the second interference correlation coefficient is between the first threshold and the second threshold When within the limited range, it is determined that there is co-channel interference in the received signal, and the first interference autocorrelation matrix is used as the obtained interference autocorrelation matrix.

Step 204: Perform interference cancellation on the received signal by using the obtained interference autocorrelation matrix.

Specifically, Cholesky decomposition is performed on the obtained interference autocorrelation matrix to obtain a lower triangular matrix, and the received signal is filtered through the inverse matrix of the lower triangular matrix to obtain a signal after interference is eliminated. The process of performing interference cancellation on the received signal by using the obtained interference autocorrelation matrix may be consistent with the prior art, and will not be repeated here.

Referring to FIG. 3A, it is a flow chart of the second embodiment of the method for eliminating co-channel interference of the present invention. This embodiment takes two regions obtained in the time-frequency domain as an example to describe the process of eliminating co-channel interference in detail:

Step 301: Select a first area and a second area in the time-frequency domain, wherein the number of pilot points in the second area is smaller than the number of pilot points in the first area.

The first area and the second area can be selected according to certain criteria combined with actual simulation results. For example, a selection criterion is: the first area needs to ensure that the interference autocorrelation matrix estimated in the first area can determine whether there is co-channel interference. When the number of pilot points in the area is large, it is easier Judging that there is no co-channel interference, when the number of pilot points in the area is small, it is easier to judge that there is co-channel interference, so the specific value of the number of pilot points N1 contained in the first area can be combined with the simulation of the actual system Obtained, preferably, the number of pilot points N1=48 in the first area; the second area needs to ensure that the interference autocorrelation matrix estimated according to the second area can determine the speed of co-channel interference change, when the second The fewer the number of pilot points in the second area, the more it can reflect the change of co-channel interference, so the specific value of N2 in the second area is simulated in the actual system. Preferably, the pilot points in the second area The number N2=16.

Referring to FIG. 3B , it is a schematic diagram of a selection area in the time-frequency domain, wherein the time domain includes several consecutive OFDM symbols, and the frequency domain includes several consecutive subcarriers. R0 in the time-frequency domain represents pilot points, wherein the number of pilot points included in the first area is 16, and the number of pilot points included in the second area is 4.

Step 302: Obtain pilot points in each area.

According to the example of step 301, after the first area and the second area are selected in the time-frequency domain, the number of pilot points in the first area is 16, and the number of pilot points in the second area is 4 .

Step 303: Calculate the interference autocorrelation matrix of each pilot point in each area.

In this step, the calculation method of the interference autocorrelation matrix of each pilot point is consistent with the prior art, and will not be repeated here.

Step 304: After accumulating the interference autocorrelation matrices of all pilot points in each area, use the average of the accumulated results as the interference autocorrelation matrix of the area.

Wherein, the average value after the accumulation of the interference autocorrelation matrices of all pilot points in the first area is used as the first interference autocorrelation matrix of the first area; after the interference autocorrelation matrix of all pilot points in the second area is accumulated The average value is used as the second interference autocorrelation matrix of the second region.

Step 305: Determine whether the first interference correlation coefficient calculated according to the first interference autocorrelation matrix of the first area is not greater than the preset first threshold, if yes, execute step 306; otherwise, execute step 307.

Among them, the elements contained in the first interference autocorrelation matrix of the first area respectively represent the interference power of different receiving antennas in the area, and the interference cross-correlation values between the antennas, and the first interference can be calculated according to the above elements The correlation coefficient, for example, for a receiver with two antennas, the first interference correlation coefficient can be defined as the ratio of the square of the interference cross-correlation value between the two antennas to the product of the interference power of the two antennas. The first threshold can be obtained by simulating the communication system. For communication systems with different numbers of antennas, the first threshold can be different. For a two-antenna communication system, preferably, the first threshold can be 0.1 .

Step 306: It is determined that there is no co-channel interference in the received signal, and the matrix obtained by setting the non-main line elements of the first interference autocorrelation matrix to zero is used as the selected interference autocorrelation matrix, and step 310 is executed.

When the first interference correlation coefficient is not greater than the preset first threshold, it can be confirmed that there is no co-channel interference in the received signal, and the matrix obtained by directly setting the non-main line elements of the first interference autocorrelation matrix to zero is used as the selected interference The autocorrelation matrix is sufficient, and then step 310 is performed to eliminate interference.

Step 307: Determine whether the second interference correlation coefficient calculated according to the second interference autocorrelation matrix of the second area is not less than the preset second threshold, if yes, execute step 308; otherwise, execute step 309.

Among them, the elements contained in the second interference autocorrelation matrix of the second area respectively represent the interference power of different receiving antennas in this area, and the interference cross-correlation values between the antennas, and the second interference autocorrelation matrix can be calculated according to the above elements The correlation coefficient, for example, for a receiver with two antennas, the second interference correlation coefficient can be defined as the ratio of the square of the interference cross-correlation value between the two antennas to the product of the interference power of the two antennas. The second threshold can be obtained according to the simulation of the communication system. For communication systems with different numbers of antennas, the second threshold can be different. For a two-antenna communication system, preferably, the first threshold can be 0.05 .

Step 308: It is determined that there is co-channel interference in the received signal, and the second interference autocorrelation matrix is used as the selected interference autocorrelation matrix, and step 310 is executed.

When the second interference correlation coefficient is not less than the preset second threshold, it can be confirmed that there is co-channel interference in the received signal, and the second interference autocorrelation matrix can be directly used as the selected interference autocorrelation matrix, and then step 310 is performed. Interference cancellation.

Step 309: Determine that there is co-channel interference in the received signal, and use the first interference autocorrelation matrix as the selected interference autocorrelation matrix.

When the second interference correlation coefficient is between the first threshold and the second threshold, it is confirmed that there is co-channel interference in the received signal, and the first interference autocorrelation matrix can be directly used as the selected interference autocorrelation matrix.

Step 310: Perform Cholesky decomposition on the acquired interference autocorrelation matrix to obtain a lower triangular matrix.

Step 311: Filter the received signal through the inverse matrix of the lower triangular matrix to obtain a signal after interference elimination.

In order to illustrate the process of co-channel interference elimination in the present invention in detail, the following takes a receiver with two receiving antennas as an example to describe a specific application example of interference elimination by selecting two regions in the time-frequency domain.

As shown in FIG. 3B , two areas are selected in the time-frequency domain, wherein the number of pilot points in the first area is 16, and the number of pilot points in the second area is 4.

Assuming that in each selected area, the received data of each pilot point Y _p =[y _1,p ,y _2,p ] ^T , the channel response of the pilot point is H _p =[h _1,p ,h _{2 , p} ] ^T , pilot point signal X _p =[x _1,p ,x _2,p ] ^T , where, for the selected first area, p=1,..,N1, for the selected second area p =1, . . . , N2.

Since the received signal at the pilot point is known, the channel response can be obtained through channel estimation. Suppose the interference on the two receiving antennas is U _p = [u _{1, p} , u _{2, p ]} ^T , then first calculate the Each element:

u _{1, p} = y _{1, p} - h _{1, p} x _{1, p}

u _{2, p} = y _{2, p} - h _{2, p} x _{2, p}

Then, calculate the interference autocorrelation matrix R _uu,p for each pilot point:

R _uu,p = U _p U _p ^H

Finally, the interference autocorrelation matrix of all pilot points in each area is accumulated and averaged to obtain the first interference autocorrelation matrix R1 and the second interference autocorrelation matrix R2 corresponding to the first area and the second area, respectively as follows:

$\mathrm{<span\; class="notranslate">\; R</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; N</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}\underset{\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; N</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{{\mathrm{<span\; class="notranslate">\; R</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}}_{\mathrm{<span\; class="notranslate">\; u\; u</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; p</span>}}<span\; class="notranslate">\; ,</span>$

$\mathrm{<span\; class="notranslate">\; R</span>}\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; N</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}\underset{\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; N</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{{\mathrm{<span\; class="notranslate">\; R</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}_{\mathrm{<span\; class="notranslate">\; u\; u</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; m</span>}}$

Wherein R ¹ _uu,p represents the interference autocorrelation matrix calculated according to the pilot points in the first area, and R ² _uu,m represents the interference autocorrelation matrix calculated according to the pilot points in the second area. Referring to FIG. 4 , it is a schematic diagram of obtaining the above-mentioned interference autocorrelation matrix through a computer program.

Assume that the calculated elements of the first interference autocorrelation matrix R1 and the second interference autocorrelation matrix R2 are as follows:

$\mathrm{<span\; class="notranslate">\; R</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; =</span>\left[\begin{array}{cc}{\mathrm{<span\; class="notranslate">\; R</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}_{\mathrm{<span\; class="notranslate">\; 11</span>}}& {\mathrm{<span\; class="notranslate">\; R</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}_{\mathrm{<span\; class="notranslate">\; 12</span>}}\\ {{\mathrm{<span\; class="notranslate">\; R</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; *</span>}}_{\mathrm{<span\; class="notranslate">\; 12</span>}}& {\mathrm{<span\; class="notranslate">\; R</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}_{\mathrm{<span\; class="notranslate">\; twenty\; two</span>}}\end{array}\right]$

$\mathrm{<span\; class="notranslate">\; R</span>}\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; =</span>\left[\begin{array}{cc}{\mathrm{<span\; class="notranslate">\; R</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}_{\mathrm{<span\; class="notranslate">\; 11</span>}}& {\mathrm{<span\; class="notranslate">\; R</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}_{\mathrm{<span\; class="notranslate">\; 12</span>}}\\ {{\mathrm{<span\; class="notranslate">\; R</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}^{<span\; class="notranslate">\; *</span>}}_{\mathrm{<span\; class="notranslate">\; 12</span>}}& {\mathrm{<span\; class="notranslate">\; R</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}_{\mathrm{<span\; class="notranslate">\; twenty\; two</span>}}\end{array}\right]$

Among them, R1 ₁₁ represents the interference power on receiving antenna 1 calculated according to the first area, R1 ₂₂ represents the interference power on receiving antenna 2 calculated according to the first area, and R1 ₁₂ represents the receiving antenna calculated according to the first area 1 and the interference cross-correlation value on receiving antenna 2; R2 ₁₁ represents the interference power on receiving antenna 1 calculated according to the second area, R2 ₂₂ represents the interference power on receiving antenna 2 calculated according to the second area, R2 ₁₂ Indicates the interference cross-correlation values on receiving antenna 1 and receiving antenna 2 calculated according to the second area.

Define the first interference correlation coefficient calculated according to the first area as |R1 ₁₂ | ² /(R1 ₁₁ R1 ₂₂ ), define the second interference correlation coefficient calculated according to the second area as |R1 ₁₂ | ² /(R1 ₁₁ R1 ₂₂ ). The process of judging co-channel interference and selecting the interference autocorrelation matrix according to the above two interference coefficients is as follows:

If |R1 ₁₂ | ² /(R1 ₁₁ R1 ₂₂ ) is less than or equal to the set first threshold value, it is judged that there is no co-channel interference. At this time, the interference in the interference autocorrelation matrix calculated according to the first area can be The cross-correlation value is set to 0, the interference power value remains unchanged, and the value of the first threshold is preferably 0.1 according to the simulation results, that is, the interference autocorrelation matrix obtained at this time

$\mathrm{<span\; class="notranslate">\; Ruu</span>}<span\; class="notranslate">\; =</span>\left[\begin{array}{cc}{\mathrm{<span\; class="notranslate">\; R</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}_{\mathrm{<span\; class="notranslate">\; 11</span>}}& \mathrm{<span\; class="notranslate">\; 0</span>}\\ \mathrm{<span\; class="notranslate">\; 0</span>}& {\mathrm{<span\; class="notranslate">\; R</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}_{\mathrm{<span\; class="notranslate">\; twenty\; two</span>}}\end{array}\right]<span\; class="notranslate">\; ;</span>$

If |R1 ₁₂ | ² /(R1 ₁₁ R1 ₂₂ ) is greater than the preset first threshold value, it is judged that there is co-channel interference, and it is further judged based on the interference autocorrelation matrix R2 in the second area to finally choose R1 or R2 as the Interference autocorrelation matrix. At this time, if |R2 ₁₂ | ² /(R2 ₁₁ R2 ₂₂ ) is greater than or equal to the preset second threshold value, and the value of the second threshold is preferably 0.05 according to the simulation results, the obtained interference autocorrelation matrix $\mathrm{Ruu}=\left[\begin{array}{cc}{R2}_{11}& {R2}_{12}\\ {{R2}^{*}}_{12}& {R2}_{\mathrm{twenty\; two}}\end{array}\right];$ If |R2 ₁₂ | ² /(R2 ₁₁ R2 ₂₂ ) is less than the preset second threshold value, the obtained interference autocorrelation matrix $\mathrm{Ruu}=\left[\begin{array}{cc}{R1}_{11}& {R1}_{12}\\ {{R1}^{*}}_{12}& {R1}_{\mathrm{twenty\; two}}\end{array}\right].$

Corresponding to the embodiment of the method for eliminating co-channel interference of the present invention, the present invention also provides an embodiment of a device for eliminating co-channel interference.

Referring to Fig. 5, it is a block diagram of an embodiment of a device for eliminating co-channel interference of the present invention:

The device for eliminating co-channel interference includes: a selection unit 510 , a calculation unit 520 , an acquisition unit 530 and a elimination unit 540 .

Wherein, the selection unit 510 is configured to select at least two regions in the time-frequency domain;

A calculation unit 520, configured to calculate the interference autocorrelation matrix of each area in at least two areas;

The acquisition unit 530 is configured to obtain an interference autocorrelation matrix from the interference autocorrelation matrices of at least two areas after judging the existence of co-channel interference according to the interference autocorrelation matrix of each area;

The elimination unit 540 is configured to perform interference elimination on the received signal by using the obtained interference autocorrelation matrix.

Referring to Fig. 6, it is a block diagram of an embodiment of the computing unit in Fig. 5:

The computing unit 520 includes:

The pilot point acquisition subunit 521 is used to acquire each pilot point in each area;

The autocorrelation matrix calculation subunit 522 is used to calculate the interference autocorrelation matrix of each pilot point in each area;

The cumulative average calculation subunit 523 is used to accumulate the interference autocorrelation matrix of all pilot points in each area to obtain an accumulation result, and use the average value of the accumulation result relative to at least two areas as the interference autocorrelation matrix of each area. correlation matrix.

Referring to FIG. 7, it is a block diagram of an embodiment of the acquisition unit in FIG. 5. In this embodiment, it is assumed that the selection unit 510 selects the first area and the second area in the time-frequency domain, and the number of pilot points in the second area is is less than the number of pilot points in the first area; the acquiring unit 530 includes:

The first coefficient judging subunit 531 is configured to judge whether the first interference correlation coefficient calculated according to the first interference autocorrelation matrix of the first area is not greater than a preset first threshold;

The first acquiring subunit 532 is configured to determine that there is no co-channel interference in the received signal when the judgment result of the first coefficient judging subunit 531 is yes, and set the non-main line of the first interference autocorrelation matrix Set the elements to zero, and use the zero-set first interference autocorrelation matrix as the acquired interference autocorrelation matrix;

The second coefficient judging subunit 533 is configured to judge whether the second interference correlation coefficient calculated according to the second interference autocorrelation matrix of the second region is calculated when the judgment result of the first coefficient judging subunit 531 is No. not less than the preset second threshold;

The second acquisition subunit 534 is configured to determine that there is co-channel interference in the received signal when the result of the judgment 533 of the second coefficient judgment subunit is yes, and use the second interference autocorrelation matrix as the acquired an interference autocorrelation matrix, and, when the judgment result of the second coefficient judging subunit 533 is No, it is determined that there is co-channel interference in the received signal, and the first interference autocorrelation matrix is used as the acquired interference autocorrelation matrix correlation matrix.

Referring to Fig. 8, it is a block diagram of an embodiment of the elimination unit in Fig. 5:

The elimination unit 540 includes:

The matrix decomposition subunit 541 is used to perform Cholesky decomposition on the obtained interference autocorrelation matrix to obtain a lower triangular matrix;

The interference elimination subunit 542 is configured to filter the received signal through the inverse matrix of the lower triangular matrix to obtain an interference-eliminated signal.

It can be seen from the above embodiments that in the embodiment of the present invention, at least two regions are selected in the time-frequency domain, the interference autocorrelation matrix of each region in the at least two regions is calculated, and the degree of co-channel interference is judged according to the interference autocorrelation matrix of each region. After the situation exists, an interference autocorrelation matrix is obtained from the interference autocorrelation matrices of at least two regions, and interference cancellation is performed on the received signal through the obtained interference autocorrelation matrix. In the embodiment of the present invention, since at least two regions are selected in the time-frequency domain to calculate the interference autocorrelation matrix, the current co-channel interference situation can be obtained by comparison, and the interference autocorrelation matrix can be selected according to the comparison result, which can improve For the accuracy of the interference autocorrelation matrix, for received signals with different degrees of same-frequency interference, a suitable interference autocorrelation matrix can be obtained by selecting a suitable interference autocorrelation matrix, thereby reducing the error of interference elimination.

Those skilled in the art can clearly understand that the technologies in the embodiments of the present invention can be implemented by means of software plus a necessary general-purpose hardware platform. Based on this understanding, the essence of the technical solutions in the embodiments of the present invention or the part that contributes to the prior art can be embodied in the form of software products, and the computer software products can be stored in storage media, such as ROM/RAM , magnetic disk, optical disk, etc., including several instructions to enable a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in various embodiments or some parts of the embodiments of the present invention.

Each embodiment in this specification is described in a progressive manner, the same and similar parts of each embodiment can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and for relevant parts, refer to part of the description of the method embodiment.

The embodiments of the present invention described above are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (8)

1. a removing method for co-channel interference, is characterized in that, comprising:

Time-frequency domain is selected at least two regions;

Calculate the interference autocorrelation matrix in each region at least two regions; In described calculating at least two regions, the interference autocorrelation matrix in each region comprises: obtain each pilot point in each region; Calculate the interference autocorrelation matrix of each pilot point in each region; In cumulative each region, the interference autocorrelation matrix of all pilot point obtains accumulation result, and the mean value of being tried to achieve relative at least two regions by accumulation result is as the interference autocorrelation matrix in described each region;

According to the interference autocorrelation matrix in each region judge co-channel interference there is situation after, in the interference autocorrelation matrix at least two regions obtain one interference autocorrelation matrix;

Carry out interference to received signal by the interference autocorrelation matrix obtained to eliminate.

2. method according to claim 1, is characterized in that, described at least two regions comprise first area and second area, and the pilot point number in described second area is less than the pilot point number in described first area.

3. method according to claim 2, is characterized in that, the described interference autocorrelation matrix according to each region judge co-channel interference there is situation after, in the interference autocorrelation matrix at least two regions obtain one interference autocorrelation matrix comprise:

When judging that the first interference coefficient correlation calculated according to the first interference autocorrelation matrix of described first area is not more than the first default thresholding, determine that described Received signal strength does not exist co-channel interference, by un-hero's line element zero setting of described first interference autocorrelation matrix, and using the interference autocorrelation matrix of the first interference autocorrelation matrix after zero setting as described acquisition;

When judging that the second interference coefficient correlation calculated according to the second interference autocorrelation matrix of described second area is not less than the second default thresholding, determine that described Received signal strength exists co-channel interference, using the interference autocorrelation matrix of described second interference autocorrelation matrix as described acquisition;

When judging that described second interference coefficient correlation is in the scope that described first thresholding and the second thresholding limit, determine that described Received signal strength exists co-channel interference, using the interference autocorrelation matrix of described first interference autocorrelation matrix as described acquisition.

4. method according to claim 1, is characterized in that, the described interference autocorrelation matrix by obtaining carries out interference elimination to received signal and comprises:

Cholesky decomposition is carried out to the interference autocorrelation matrix obtained and obtains inferior triangular flap;

By the inverse matrix of described inferior triangular flap, filtering process is carried out to described Received signal strength, the signal after the interference that is eliminated.

5. a cancellation element for co-channel interference, is characterized in that, comprising:

Selected cell, for selecting at least two regions on time-frequency domain;

Computing unit, for calculating the interference autocorrelation matrix in each region at least two regions; Described computing unit comprises:

Pilot point obtains subelement, for obtaining each pilot point in each region; Autocorrelation matrix computation subunit, for calculating the interference autocorrelation matrix of each pilot point in each region; Cumulative mean computation subunit, obtains accumulation result for the interference autocorrelation matrix of all pilot point in cumulative each region, and the mean value of being tried to achieve relative at least two regions by accumulation result is as the interference autocorrelation matrix in described each region;

Acquiring unit, for judge according to the interference autocorrelation matrix in each region co-channel interference there is situation after, in the interference autocorrelation matrix at least two regions obtain one interference autocorrelation matrix;

Eliminate unit, carry out interference to received signal for the interference autocorrelation matrix by obtaining and eliminate.

6. device according to claim 5, is characterized in that, described at least two regions comprise first area and second area, and the pilot point number in described second area is less than the pilot point number in described first area.

7. device according to claim 6, is characterized in that, described acquiring unit comprises:

First coefficient judgment sub-unit, for judging whether the first interference coefficient correlation calculated according to the first interference autocorrelation matrix of described first area is not more than the first default thresholding;

First obtains subelement, for when the judged result of described first coefficient judgment sub-unit is for being, determine that described Received signal strength does not exist co-channel interference, by un-hero's line element zero setting of described first interference autocorrelation matrix, and using the interference autocorrelation matrix of the first interference autocorrelation matrix after zero setting as described acquisition;

Second coefficient judgment sub-unit, for when the judged result of described first coefficient judgment sub-unit is no, judges whether the second interference coefficient correlation calculated according to the second interference autocorrelation matrix of described second area is not less than the second default thresholding;

Second obtains subelement, for when the judged result of described second coefficient judgment sub-unit is for being, determine that described Received signal strength exists co-channel interference, using the interference autocorrelation matrix of described second interference autocorrelation matrix as described acquisition, and, when the judged result of described second coefficient judgment sub-unit is no, determine that described Received signal strength exists co-channel interference, using the interference autocorrelation matrix of described first interference autocorrelation matrix as described acquisition.

8. device according to claim 5, is characterized in that, described elimination unit comprises:

Matrix decomposition subelement, obtains inferior triangular flap for carrying out Cholesky decomposition to the interference autocorrelation matrix obtained;

Subelement is eliminated in interference, carries out filtering process for the inverse matrix by described inferior triangular flap to described Received signal strength, the signal after the interference that is eliminated.