JP5675313B2 - Signal separation system and signal separation device - Google Patents

Description

  The present invention relates to a signal separation system and a signal separation device that separate interference reception signals from a plurality of systems into reception signals for each system.

  As a method of separating interference reception signals from terminals that communicate with periodicity, when each terminal belongs to a system with a different transmission period, it detects the periodicity of the signals included in the interference reception signal and detects the detection period. A method has been proposed in which the system is separated by testing the signal and separating the signal at each detection cycle (see, for example, Japanese Patent Application No. 2009-274420 filed on Dec. 2, 2009).

  In this prior application (Japanese Patent Application No. 2009-274420), since each signal is separated for each system on the basis of the transmission period of each system, the system cannot be separated when the transmission period is the same in each system. There was a point.

  The present invention has been made in order to solve the above-described problems. Even when the transmission cycle of a plurality of systems is the same, the received signal is received under different conditions of the combination of frequencies used in each system. It is an object of the present invention to obtain a signal separation system and a signal separation device that can separate a received signal for each system by using a statistic of the frequency appearance number.

A signal separation system according to the present invention includes a reception device that receives radio waves from a plurality of terminals that belong to a plurality of systems, and a signal separation device that applies a predetermined algorithm to an interference reception signal obtained from the reception device. The signal separation device includes: a signal dividing unit that generates an interference reception signal sequence divided at predetermined time intervals with respect to an input interference reception signal sequence; and the divided interference reception signal sequence as a row. Then, a first matrix having a frequency appearing in the input interference received signal sequence as a column is generated, and the number of appearances of the frequency in each divided interference received signal sequence is assigned to the corresponding column in the first matrix. an appearance frequency calculation unit, and the covariance calculation unit for calculating a covariance matrix for a first matrix, and the eigenvalue decomposition of the covariance matrix, and the eigenvalue decomposition unit to obtain the eigenvalues and eigenvectors, wherein the eigenvalue decomposition An evaluation value calculation unit for calculating a result eigenvector corresponding to a plurality of large eigenvalues obtained as an evaluation value, for each column of the evaluation value, and calculates an evaluation value determination index based on the value of the set value or the elements An evaluation value determination index calculation unit and a system separation unit that separates frequencies corresponding to rows having a value exceeding the evaluation value determination index as the same system frequency with respect to the evaluation value.

  According to the signal separation system of the present invention, even when a plurality of systems have the same transmission period, the statistics of the frequency appearance number of the received signal are used under the condition that the combination of frequencies used in each system is different. Thus, the received signal can be separated for each system.

It is a figure which shows the structure of the signal separation system which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the signal separation system which concerns on Embodiment 1 of this invention. It is a figure which shows the structure and schematic operation | movement of the signal separation apparatus of the signal separation system which concerns on Embodiment 1 of this invention. It is a figure which shows the interference received signal which the signal separation system which concerns on Embodiment 1 of this invention receives. It is a figure which shows another structure and schematic operation | movement of the signal separation apparatus of the signal separation system which concerns on Embodiment 1 of this invention. It is a figure which shows the structure and schematic operation | movement of the signal separation apparatus of the signal separation system which concerns on Embodiment 2 of this invention.

  Hereinafter, preferred embodiments of a signal separation system of the present invention will be described with reference to the drawings.

Embodiment 1 FIG.
A signal separation system according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 is a diagram showing a configuration of a signal separation system according to Embodiment 1 of the present invention. In the following, in each figure, the same reference numerals indicate the same or corresponding parts.

  In FIG. 1, the signal separation system according to Embodiment 1 of the present invention includes an antenna or the like, and receives a receiving device 10 that receives incoming signals from a plurality of systems, and receives data obtained from the receiving device 10. A signal separation device 20 to which the algorithm of the present invention is applied and a display device 30 for displaying and recording a signal separation result obtained by the signal separation device 20 are provided.

  Further, the terminal 1, the terminal 2, and the terminal 3 belong to the system A. A terminal 4, a terminal 5, a terminal 6, and a terminal 7 belong to the system B.

  FIG. 2 is a diagram showing the configuration of the signal separation system according to Embodiment 1 of the present invention, as in FIG.

  In FIG. 2, terminal 1 and terminal 2 belong to system A. The terminal 3 and the terminal 4 belong to the system B. The terminal 5 and the terminal 6 belong to the system C. The terminal 7 and the terminal 8 belong to the system D.

  In FIG. 1, the signal separation system according to Embodiment 1 of the present invention is intended for a communication system in which a plurality of terminals are included in one system. In FIG. 2, two terminals face each other in one system. It is intended for a communication system in the case of performing communication with. In the communication system of FIG. 1, a terminal belonging to any of a plurality of systems divided for each purpose and application can select a transmission frequency from a combination of transmission frequencies given to each system in advance or according to the situation. Select to send. In the communication system of FIG. 2, signals are transmitted using a frequency combination determined by terminals.

  FIG. 3 is a diagram showing the configuration and schematic operation of the signal separation device of the signal separation system according to Embodiment 1 of the present invention.

  In FIG. 3, the signal separation device 20 includes a signal division unit 201 that divides a signal, an appearance frequency calculation unit 202 that calculates an appearance frequency, a difference calculation unit 203 that calculates a difference, and a covariance calculation that calculates a covariance. Unit 204, eigenvalue decomposition unit 205 for decomposing eigenvalues, evaluation value calculation unit 206 for calculating evaluation values, evaluation value determination index calculation unit 207 for calculating evaluation value determination indexes, and system separation unit 208 for separating systems A period detection unit 211 that detects a period, and a terminal separation unit 212 that separates terminals.

  Next, the operation of the signal separation system according to the first embodiment will be described with reference to the drawings.

  FIG. 4 is a diagram showing an interference reception signal received by the signal separation system according to Embodiment 1 of the present invention.

  A terminal (radio wave source) belonging to one of a plurality of systems divided according to purpose or application selects a frequency used for signal transmission from different frequency combinations determined for each system for each transmission timing, and transmits a signal. When transmitting a signal using a predetermined frequency combination between terminals, pay attention to the fact that the combination of frequencies used in each system is different, and use the statistics of the frequency appearance frequency in the received signal Thus, the signal is separated for each system or terminal.

  If communication occurs in each system or terminal, the frequency of appearance of frequencies used in that system or terminal increases. Considering that the communication occurrence timing between each system or terminal is uncorrelated, the frequency appearance frequency per fixed time is considered to vary greatly depending on the presence or absence of communication of each system or terminal, and the frequency used by the same system or terminal The number of appearances is expected to change in conjunction.

  By statistically processing the frequency that changes in conjunction with this, by detecting the frequency combination that is statistically used at the same timing, referring to the frequency of the received signal, and separating the received signal by the above-described detected frequency combination The received signal is separated for each system or terminal.

  If the terminals of each system transmit signals with periodicity, the transmission period is detected, and the results separated for each system are tested at the detection period, and the signals are separated for each terminal. It is also possible to do.

  In the first embodiment, when there are a plurality of types of systems and there are terminals that perform communication with the same periodicity in each system, a procedure for performing the separation process by the following method will be specifically described. . Here, the case where the process is performed on the communication system of FIG. 1 will be described in detail, but the same process is also performed on the communication system as shown in FIG.

The signal division unit 201 of the signal separation device 20, as shown in FIG. 4, performs the interference reception signal sequence R _i (i = 1, 1) divided for each arbitrarily set time interval T _Unit with respect to the interference reception signal sequence R. 2,..., I).

The appearance frequency calculation unit 202 generates a matrix A having the divided interference reception signal sequence R _i as a row and frequencies f _j (j = 1, 2,..., F) appearing in the interference reception signal sequence R as columns. and substitutes the number of occurrences N _RI frequency at each division interference received signal sequence in R _i, a _fF in the corresponding column.

The difference calculation unit 203 calculates the difference in the number of appearances of the frequency with respect to the matrix A and the signal sequence that appears in a time zone shifted by an arbitrarily set time interval T _Unit , and the matrix B = A _{i + 1, j} −A _{Let i, j} .

  The covariance calculation unit 204 calculates a covariance matrix C for the matrix B. The matrix C represents how the frequency changes per time interval arbitrarily set based on each frequency of the matrix B. That is, if the covariance is high, it is considered that the generation (or disappearance) of signals occurs at the same timing between the corresponding frequencies.

  The eigenvalue decomposition unit 205 sets the result of eigenvalue decomposition of the covariance matrix C as eigenvalue D and eigenvector V.

  If the evaluation value calculation unit 206 obtains k (k = 1, 2,..., K) large eigenvalues, the evaluation value calculation unit 206 calculates the corresponding eigenvector as the evaluation value F (:, k).

  Here, as the evaluation value, a result obtained by multiplying the matrix C by the eigenvector may be used as the evaluation value as follows.

The evaluation value determination index calculation unit 207 calculates an evaluation value determination index. As a method for calculating the evaluation value determination index, the following method can be considered.
An arbitrarily set value is used as an evaluation value determination index for each column of evaluation values F (:, k).
The average value for each element is used as an evaluation value determination index for each column of evaluation values F (:, k).
For each column of evaluation values F (:, k), an average value μ and a standard deviation σ for each element are obtained, and μ + Lσ (where L is arbitrarily set) is used as an evaluation value determination index.
A value obtained by adding the difference between the maximum value and the minimum value of each element to the minimum value for each column of the evaluation values F (:, k) is used as an evaluation value determination index.

  The system separation unit 208 separates the frequency corresponding to the row having a value exceeding the calculated evaluation value determination index from the evaluation value F (:, k) as the same system frequency, and determines the reception frequency of each reception signal. The received signal is separated into a system having a matching frequency by using the result of the frequency combination for each system separated as the same system frequency.

  When the signal to be analyzed communicates with time periodicity, the period detection unit 211 performs autocorrelation processing on the received signal sequence separated for each system by the system separation unit 208, and displays the autocorrelation processing result. On the other hand, the period of the received signal is detected by performing the PRI conversion process, which is a process for detecting the period by converting the time periodicity into a phase component and accumulating the phase.

  The terminal separation unit 212 uses the period detected by the period detection unit 211 to group signals received at integer multiples of the period as signals from the same terminal with respect to the reception time of the signal to be verified. The received signal is separated for each system, and further separated for each terminal.

  Through these processes, the interference reception signal can be separated for each system and further separated for each terminal.

  In FIG. 3, the signal dividing unit 201, the appearance frequency calculating unit 202, the difference calculating unit 203, the covariance calculating unit 204, the eigenvalue decomposing unit 205, the evaluation value calculating unit 206, and the evaluation value determination that constitute the signal separation device 20. Of the index calculation unit 207 and the system separation unit 208, even when the difference calculation unit 203 is not provided, the received signal can be separated for each system under the condition that the combination of frequencies used in each system is different.

  That is, the covariance calculation unit 204 calculates a covariance matrix C for the matrix A generated by the appearance frequency calculation unit 202.

  FIG. 5 is a diagram showing another configuration and schematic operation of the signal separation device of the signal separation system according to Embodiment 1 of the present invention.

  In FIG. 5, the cycle detection unit 211 performs parallel processing on the processing after the signal division unit 201. Except for this parallel processing, the operation is the same as that of each unit in FIG.

  The period detection unit 211 performs autocorrelation processing on the interference reception signal sequence R as shown in FIG. The period of the received signal is detected by performing the PRI conversion process, which is the process of detecting the period by converting the signal to the phase and then accumulating the phases.

  The terminal separation unit 212 uses the period detected by the period detection unit 211 for the reception signal sequence separated for each system by the system separation unit 208, and uses the period detected by the period detection unit 211 as an integer of the period. By grouping the signals received at the double position as signals from the same terminal, the received signals are separated for each system and further separated for each terminal.

  Through these processes, the interference reception signal can be separated for each system and further separated for each terminal.

  In FIG. 5, the signal dividing unit 201, the appearance frequency calculating unit 202, the difference calculating unit 203, the covariance calculating unit 204, the eigenvalue decomposing unit 205, the evaluation value calculating unit 206, the evaluation value determination, which constitute the signal separating device 20 Among the index calculation unit 207, the system separation unit 208, the period detection unit 211, and the terminal separation unit 212, even when the difference calculation unit 203 is not provided, the received signal is transmitted under the condition that the combination of frequencies used in each system is different. Further, it can be separated for each terminal.

  That is, the covariance calculation unit 204 calculates a covariance matrix C for the matrix A generated by the appearance frequency calculation unit 202.

  In FIG. 5, the signal division unit 201 may use the period detected by the period detection unit 211 as the time interval instead of the set time interval.

Embodiment 2. FIG.
A signal separation system according to Embodiment 2 of the present invention will be described with reference to FIG. FIG. 6 is a diagram showing a configuration and a schematic operation of a signal separation device of a signal separation system according to Embodiment 2 of the present invention. The configuration of the signal separation system according to the second embodiment of the present invention is the same as that of the first embodiment except for the signal separation device 20.

  In FIG. 6, the signal separation device 20 includes a period detection unit 211 that detects a period, a terminal separation unit 212 that separates terminals, an appearance frequency calculation unit 202A for each terminal that calculates an appearance frequency for each terminal, and a covariance A covariance calculation unit 204 that calculates the eigenvalue, an eigenvalue decomposition unit 205 that decomposes the eigenvalue, an evaluation value calculation unit 206 that calculates an evaluation value, an evaluation value determination index calculation unit 207 that calculates an evaluation value determination index, and a system A system separation unit 208 for separation and a system reseparation determination unit 213 are provided.

  Next, the operation of the signal separation system according to the second embodiment will be described with reference to the drawings.

  In the second embodiment, when there are a plurality of types of systems, and there are terminals that perform communication with the same periodicity in each system, a procedure for performing the separation process by the following method will be specifically described. . Here, the case where the process is performed on the communication system of FIG. 1 will be described in detail, but the same process is also performed on the communication system as shown in FIG.

  The period detection unit 211 performs autocorrelation processing on the interference reception signal sequence R as shown in FIG. 4 and converts the time periodicity into phase components for the autocorrelation processing result to accumulate the phases. The period of the received signal is detected by performing the PRI conversion process, which is a process for detecting the period.

The terminal separation unit 212 uses the period detected by the period detection unit 211 to group the signals received at integer multiples of the period as signals from the same terminal with respect to the reception time of the signal to be verified. The received signal is separated for each terminal. As a result of terminal separation, it is assumed that P terminals ND _i (i = 1, 2,..., P) are obtained.

The appearance frequency calculation unit 202A for each terminal refers to the frequency of the received signal included in each of the P terminals obtained by the terminal separation unit 212, and calculates a frequency statistic FCNT _{NDi, fj} used in each terminal. To do. A matrix A is generated with the terminal ND (i) obtained by the terminal separation unit 212 as a row and the frequency f _j (j = 1, 2,..., F) appearing in the interference received signal sequence R as a column. The calculated frequency statistic FCNT _{NDi, fj} used in each terminal is substituted for the element of the matrix A.

  The covariance calculation unit 204 calculates a covariance matrix B for the matrix A. Since the covariance matrix B calculates the covariance in the column direction of the matrix A, the similarity of the frequency appearance frequency at each calculation terminal is calculated based on each frequency. (Conceptually, this represents the degree to which one frequency f1 and another frequency f2 are used in the same terminal.)

  The eigenvalue decomposition unit 205 sets the result of eigenvalue decomposition of the covariance matrix B as eigenvalue D and eigenvector V.

  If the evaluation value calculation unit 206 obtains k (k = 1, 2,..., K) large eigenvalues, the evaluation value calculation unit 206 calculates the corresponding eigenvector as the evaluation value F (:, k).

  Here, as the evaluation value, a result obtained by multiplying the matrix B by the eigenvector may be used as the evaluation value as follows.

The evaluation value determination index calculation unit 207 calculates an evaluation value determination index. As a method for calculating the evaluation value determination index, the following method can be considered.
An arbitrarily set value is used as an evaluation value determination index for each column of evaluation values F (:, k).
The average value for each element is used as an evaluation value determination index for each column of evaluation values F (:, k).
For each column of evaluation values F (:, k), an average value μ and a standard deviation σ for each element are obtained, and μ + Lσ (where L is arbitrarily set) is used as an evaluation value determination index.
A value obtained by adding the difference between the maximum value and the minimum value of each element to the minimum value for each column of the evaluation values F (:, k) is used as an evaluation value determination index.

  The system separation unit 208 separates the frequency corresponding to the row having a value exceeding the calculated evaluation value determination index from the evaluation value F (:, k) as the same system frequency, and determines the reception frequency of each reception signal. The received signal is separated into a system having a matching frequency by using the result of the frequency combination for each system separated as the same system frequency.

  The system re-separation determining unit 213 displays the appearance frequency information for each system when a combination in which one terminal belongs to two systems occurs with respect to the reception signal separation result for each system by the system separation unit 208. Based on this, the terminal is re-separated into a plurality of systems.

  Through these processes, the system of each terminal can be separated using the statistical information of the frequency used in each terminal.

  DESCRIPTION OF SYMBOLS 10 Receiving device, 20 Signal separation device, 30 Display device, 201 Signal dividing unit, 202 Appearance frequency calculation unit, 202A Appearance frequency calculation unit for each terminal, 203 Difference calculation unit, 204 Covariance calculation unit, 205 Eigenvalue decomposition unit, 206 Evaluation value calculation unit, 207 Evaluation value determination index calculation unit, 208 System separation unit, 211 Period detection unit, 212 Terminal separation unit, 213 System reseparation determination unit

Claims (8)

A receiving device for receiving radio waves from a plurality of terminals respectively belonging to a plurality of systems;
A signal separation device that applies a predetermined algorithm to the interference reception signal obtained from the reception device,
The signal separation device comprises:
A signal dividing unit that generates an interference reception signal sequence divided at predetermined time intervals for the input interference reception signal sequence;
A first matrix is generated in which the divided interference reception signal sequence is a row, and the frequency appearing in the input interference reception signal sequence is generated, and the number of appearances of the frequency in each division interference reception signal sequence is set to the first matrix . An appearance frequency calculation unit that substitutes the corresponding column in the matrix of
A covariance calculation unit for calculating a covariance matrix for the first matrix;
An eigenvalue decomposition unit for eigenvalue decomposition of the covariance matrix to obtain eigenvalues and eigenvectors;
An evaluation value calculation unit that calculates eigenvectors corresponding to a plurality of large eigenvalues obtained by the eigenvalue decomposition as evaluation values;
For each column of the evaluation values, an evaluation value determination index calculation unit that calculates an evaluation value determination index based on the set value or the value of each element;
A signal separation system comprising: a system separation unit that separates a frequency corresponding to a row having a value exceeding the evaluation value determination index with respect to the evaluation value as a frequency of the same system. The signal separation device comprises:
A difference calculating unit that calculates a second matrix that is a difference between the first matrix and a matrix that represents an appearance frequency of a time zone shifted by the predetermined time interval;
The signal separation system according to claim 1, wherein the covariance calculation unit calculates a covariance matrix for the second matrix instead of the first matrix. The signal separation device comprises:
When the signal to be analyzed communicates with time periodicity, autocorrelation processing is performed on the received signal sequence separated for each system by the system separation unit, and the time periodicity is obtained for the autocorrelation processing result. A period detection unit that detects a period of a received signal by performing a PRI conversion process, which is a process of detecting a period by converting the signal into a phase component and accumulating the phase;
By using the period detected by the period detection unit and grouping the signals received at integer multiples of the period with respect to the reception time of the signal to be verified, the received signals are grouped as signals from the same terminal. The signal separation system according to claim 1, further comprising: a terminal separation unit that separates each terminal into separate terminals. The signal separation device comprises:
In parallel with the signal division unit, auto-correlation processing is performed on the input interference received signal sequence, and time auto-correlation processing results are converted into a phase component by converting time periodicity to a period. A period detection unit that detects a period of the received signal by performing a PRI conversion process that is a process of detecting
A signal received at an integer multiple of the period with respect to the reception time of the signal to be tested, using the period detected by the period detection unit for the received signal sequence separated for each system by the system separation unit 3. The signal separation system according to claim 1, further comprising: a terminal separation unit that separates reception signals for each system by grouping signals as signals from the same terminal, and further separates the received signals for each terminal. . The signal separation system according to claim 4, wherein the signal dividing unit sets the predetermined time interval to a period detected by the period detecting unit instead of setting the predetermined time interval. Refers to the frequency of the received signal included in each of the plurality of terminals, calculates the statistic of the frequency used in each terminal, and uses each of the plurality of terminals as a row, and the frequency appearing in the input interference received signal sequence And a matrix for generating the appearance frequency for each terminal that substitutes the calculated statistics of the frequency used in each terminal for the elements of the matrix,
A covariance calculator that calculates a covariance matrix for the matrix;
An eigenvalue decomposition unit for eigenvalue decomposition of the covariance matrix to obtain eigenvalues and eigenvectors;
An evaluation value calculation unit that calculates eigenvectors corresponding to a plurality of large eigenvalues obtained by the eigenvalue decomposition as evaluation values;
For each column of the evaluation values, an evaluation value determination index calculation unit that calculates an evaluation value determination index based on the set value or the value of each element;
A signal separation device comprising: a system separation unit that separates a frequency corresponding to a row having a value exceeding the evaluation value determination index from the evaluation value as a frequency of the same system. PRI conversion, which is a process for detecting a cycle by performing autocorrelation processing on the input interference received signal sequence and converting the time periodicity into a phase component and accumulating the phase of the autocorrelation processing result By performing processing, a period detector that detects the period of the received signal;
By using the period detected by the period detection unit and grouping the signals received at integer multiples of the period with respect to the reception time of the signal to be verified, the received signals are grouped as signals from the same terminal. The signal separation device according to claim 6, further comprising: a terminal separation unit that separates the signal into a terminal. When a combination in which one terminal belongs to two systems occurs with respect to the result of separating received signals for each system by the system separating unit, the terminal is divided into a plurality of systems based on the appearance frequency information for each system. The signal separation device according to claim 6, further comprising a system re-separation determination unit that re-separates the signal.

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