JP2010273019A - Interference separator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an interference separator improved in the accuracy of interference separation by accurately separating even signals whose transmission frequency change and signals whose incoming time are similar. <P>SOLUTION: In the interference separator including a signal connecting means 32 for outputting all connection patterns that are candidates, and a reference pattern storing means 33 for storing a plurality of reference patterns based on the past statistical information, a determining means 35 respectively calculates evaluation values of all of the connection patters that are candidates with reference to a reference pattern corresponding to a feature extraction result of a chip included in the connection patterns, and extracts a desired signal on the basis of the evaluation values from the all of the connection patterns that are candidates. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an interference separation device that separates and extracts a desired signal from an interference signal in which a plurality of communication waves interfere.

  In a conventional interference separation device, when signals from a plurality of transmitters are mixedly received, signal characteristics such as transmission frequency, arrival direction, signal length, and arrival time of each signal are extracted, and the extracted characteristics Using the similarity and the periodicity of the arrival time, the desired signals are separated by connecting the mixed signals for each series. Further, by taking into consideration the presence of false detection and loss detection of the signal, the performance of separating and extracting a desired signal from the interference signal (hereinafter referred to as interference separation) is prevented from degrading ( For example, see Patent Document 1).

JP 2001-147264 A

  As a wireless communication method, there is a method of switching a carrier wave frequency (hereinafter referred to as a transmission frequency) of a transmission signal according to time, such as an MCA (Multi Channel Access) method or an FH (Frequency Hopping) method. A signal block having predetermined characteristics is hereinafter referred to as a chip. In the MCA method, the FH method, and the like, there is a certain appearance period in which a plurality of chips having different characteristics such as a transmission frequency are connected. That is, if the time information and frequency information at which the transmission frequency is switched are known, the signal can be received without interruption by switching the reception frequency of the receiver to the frequency determined at the determined time according to the known information. However, when it is not possible to know in advance the time information and frequency information at which the transmission frequency switches, in order to reproduce uninterrupted reception, various signals are received in advance by a receiver with a wide reception band, and the received signal A signal with good continuity must be selected from the inside.

  In a conventional interference separation apparatus, signals that are transmitted from the same transmitter select a desired signal using the similarity of chip characteristics on the assumption that the chip characteristics such as transmission frequency and arrival direction are similar. For this reason, there is a problem that signals such as the MCA method and the FH method whose chip characteristics (transmission frequency) change cannot be accurately separated. Further, in the conventional interference separating apparatus, since a desired signal is selected based on the periodicity of the arrival time, there is a problem that signals having similar arrival times cannot be accurately separated.

  The present invention has been made to solve such a problem, and can accurately separate a signal whose transmission frequency changes or a signal having a similar arrival time, and has improved interference separation accuracy. The object is to provide a separation device.

  The crosstalk separation device according to the present invention extracts a feature for each chip from a received signal and outputs it as a feature extraction result, and a plurality of chips connected by connecting a plurality of chips based on the feature extraction result. Based on signal connection means for outputting a pattern, reference pattern storage means for holding a plurality of reference patterns corresponding to the features, and evaluation values of the connection patterns with respect to the reference patterns corresponding to the chip feature extraction results included in the connection patterns Determining means for extracting a desired signal from all the connection patterns that can be candidates.

  The present invention holds a plurality of reference patterns based on past statistical information, and can be a candidate based on a connection pattern evaluation value for a reference pattern according to a feature extraction result of a chip included in the candidate connection pattern. Since a desired signal is extracted from all connection patterns, the accuracy of interference separation is improved.

It is a block diagram which shows the structure of the interference separation apparatus by Embodiment 1 of this invention. It is explanatory drawing which shows the received signal input into the interference separation apparatus by Embodiment 1 of this invention. It is explanatory drawing which shows the reference pattern accumulate | stored in the reference pattern storage means by Embodiment 1 of this invention. It is explanatory drawing which shows the received signal input into the interference separation apparatus by Embodiment 1 of this invention. It is explanatory drawing which shows the reference pattern accumulate | stored in the reference pattern storage means by Embodiment 1 of this invention. It is a block diagram which shows the structure of the interference separation apparatus by Embodiment 2 of this invention.

  Each embodiment of the interference separating apparatus according to the present invention will be described with reference to the drawings. In the following drawings, the same reference numerals indicate the same or corresponding configurations.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing the configuration of an interference separation apparatus according to Embodiment 1 of the present invention. A reception signal received by the receiver 2 via the antenna 1 is output to the interference separation device 3. The interference separation device 3 includes a feature extraction unit 31, a signal connection unit 32, a reference pattern storage unit 33, and a determination unit 34.

  Next, the operation will be described. FIG. 2 is an explanatory diagram showing a received signal input to the interference separation device 3 according to the first embodiment of the present invention. A reception signal from the receiver 2 is first input to the feature extraction unit 31. The feature extraction unit 31 extracts the features of each chip R1, R2A, R2B, R3, R4A, R4B, and R5 of the received signal and outputs them to the signal connection unit 32 as a feature extraction result. As the feature extraction result, for example, the reception frequency, reception start time, reception end time, arrival direction, frequency bandwidth, modulation method, and the like of each chip can be considered. The feature extraction unit 31 outputs the received signal and the extracted feature extraction result to the signal connection unit 32.

  The signal connecting unit 32 connects the chips as a series of signals based on the reception start time and reception end time (hereinafter referred to as time) of the feature extraction result, and outputs the result to the determination unit 34 as a connection pattern. The signal connection means 32 does not necessarily output only the best connection pattern, but redundantly outputs all connection patterns that can be candidates.

  In FIG. 2, chips R1, R2A, R3, R4A, and R5 are desired signals, and chips R2B and R4B are unnecessary signals. When the received signal shown in FIG. 2 is input to the signal connecting means 32, it is determined that the chip R4B cannot be connected to the preceding and subsequent chips R3, R5 based on the time, and is excluded by the signal connecting means 32. However, since the chip R2B can be connected to the front and rear chips R1, R3 based on the time, it is not excluded by the signal connecting means 32.

  From the time alone, it is not known whether each chip should be connected in the order of R1, R2A, R3, R4A, and R5, or each chip should be connected in the order of R1, R2, B, R3, R4A, and R5. The signal connection means 32 outputs all possible connection patterns based on the time. For example, when the received signal shown in FIG. 2 is received, the signal connecting unit 32 determines that R1 → R2A → R3 → R4A → R5 and R1 → R2B → R3 → R4A → R5 are candidate connection patterns. 34.

  FIG. 3 is an explanatory diagram showing reference patterns stored in the reference pattern storage unit 33 according to the first embodiment of the present invention. The reference pattern accumulation unit 33 holds a plurality of reference patterns based on past statistical information. For example, if it is known from the past statistical information that the connection pattern of the signals flying depending on the time zone is different, the reference pattern accumulating unit 33 holds a plurality of reference patterns according to time and is input to the determining unit 34 A reference pattern corresponding to the chip feature extraction result included in the connection pattern is output to the determination unit 34. For example, when the reference pattern storage unit 33 holds four reference patterns corresponding to each time zone from 0 o'clock to 6 o'clock, 6 o'clock to 12 o'clock, 12 o'clock to 18 o'clock, and 18 o'clock to 24 o'clock, If the time of the feature extraction result of the chip included in the candidate connection pattern is 2 o'clock, a reference pattern corresponding to the time zone from 0:00 to 6:00 is output to the determination unit 34.

The determination unit 34 refers to the output from the reference pattern storage unit 33, selects the best connection pattern from the connection pattern candidates output by the signal connection unit 32, and outputs it as a desired signal. In order to select the best connection pattern, the determination unit 34 calculates an evaluation value of the connection pattern with respect to the reference pattern for each candidate. The evaluation value is calculated by the function fn (X, Y). X is one of the candidate connection patterns output from the signal connection means 32, and Y is a reference pattern output from the reference pattern storage means 33. Here, the connection pattern of R1 → R2A → R3 → R4A → R5 is X ₁ , the connection pattern of R1 → R2B → R3 → R4A → R5 is X ₂ , and the reference pattern K1 → K2 → K3 → K4 → K5 shown in FIG. It is referred to as _{Y 1.}

For example, it is assumed that the function f ₁ (X, Y) is a function that evaluates the number of coincidence of vertical frequency changes. Vertical change of frequency in the connection pattern X ₁ is increased → a descending → descending → descending, vertical change of frequency in the reference pattern Y ₁ is a is a rise → descending → descending → lowered number of matches is 4 times , F ₁ (X ₁ , Y ₁ ) = 4. Further, the upper and lower change in frequency in the link pattern _{X 2} is, since the falling → rise → descending → descending match the number of the reference pattern _{Y 1} is 2 _times, f ₁ (X _{2, Y} 1) = 2 and Become. Since the evaluation values of the connection patterns X ₁ and X ₂ with respect to the reference pattern Y ₁ are f ₁ (X ₁ , Y ₁ ) = 4 and f ₁ (X ₂ , Y ₁ ) = 2, respectively, the determination unit 34 evaluates values and outputs the greatest connection pattern X ₁ as the desired signal.

FIG. 4 is an explanatory diagram showing a received signal input to the interference separation device 3 according to the first embodiment of the present invention, and FIG. 5 is a reference pattern stored in the reference pattern storage means 33 according to the first embodiment of the present invention. It is explanatory drawing which shows. If the received signal shown in FIG. 4 is input, connection pattern of the signal coupling means 32 is connected pattern _X 3 as a connecting pattern to be a candidate R6 → R7A → R8 → R9 → R10, R6 → R7B → R8 → R9 → R10 and it outputs the X _4. If the time of the feature extraction result of the chip included in the candidate connection patterns X ₃ and X ₄ is 7 o'clock, the reference pattern Y ₂ corresponding to the time zone from 6 o'clock to 12 o'clock is input to the determination unit 34. The The reference pattern K6 → K7 → K8 → K9 → K10 shown in FIG. 5 and _{Y 2.}

Here, the above-described function _f 1 (X, Y) when assessed the connecting pattern _X 3, _{X 4} as a candidate with, both the evaluation value of the connection patterns _X 3, _{X 4} with respect to the reference pattern _{Y 2} f ₁ (X ₃ , Y ₂ ) = f ₁ (X ₄ , Y ₂ ) = 4, and it is impossible to determine which connection pattern is a desired signal.

For example, in the time zone from 6 o'clock to 12 o'clock, if statistical information that unnecessary signals (unnecessary chip R7B) having similar frequency changes are detected is accumulated, the statistical information is determined according to the statistical information. The determination means 34 extracts a desired signal using the function. That is, rather than the function f _{1 (X,} Y) for evaluating the number of coincidences of the upper and lower change in frequency, for example, to the use of the function f ₂ for evaluating the number of coincidences of variation of the frequency _(X, Y). Regarding the coincidence / non-coincidence of the frequency change amount, if the frequency change amount in the reference pattern Y is within a predetermined range (for example, within ± 10%), it is determined as coincidence.

Variation of the frequency in the reference pattern _{Y 2} shown in FIG. 5, + Δf → -Δf → -1.5Δf → + a 0.5Derutaf, the amount of change in frequency in the connection patterns _{X 3} shown in FIG. 4, + Δf → -Δf → −1.5Δf → + 0.5Δf. Therefore, the evaluation value is f ₂ (X ₃ , Y ₂ ) = 4. On the other hand, the amount of change in frequency in the connection pattern _{X 4} is a + 1.5Δf → -1.5Δf → -1.5Δf → + 0.5Δf. Since the frequency change amount + 1.5Δf in R6 → R7B is not within the range of ± 10% with respect to the frequency change amount + Δf in K6 → K7, it is determined as a mismatch. Similarly, the amount of change in frequency in R7B → R8 is also determined to be inconsistent, so the evaluation value is f ₂ (X ₄ , Y ₂ ) = 2. Since the evaluation value of the connection patterns _X 3, _{X 4} with respect to the reference pattern _{Y 2} each _{f 2 (X 3, Y 2} ) = 4, is _{f 2 (X 4, Y 2} ) = 2, determination means 34, evaluation values and outputs the greatest connection pattern X ₃ as the desired signal.

  In the first embodiment, an example in which the reference pattern storage unit 33 holds a plurality of reference patterns according to time has been described. However, in addition to the time, for example, according to the arrival direction, frequency band, modulation method, and the like A reference pattern may be held. Further, a reference pattern (for example, a reference pattern corresponding to the northeast arrival direction and the frequency band corresponding to the 400 MHz band) may be held for each combination of these types.

  There is a possibility that the feature extraction results of the arrival direction, frequency band, modulation method, etc. of each chip included in the candidate connection pattern may be different. When selecting one reference pattern from a plurality of reference patterns according to the direction of arrival, frequency band, modulation method, etc. and outputting it to the determination means 34, check the feature extraction results of all chips included in the candidate connection pattern The reference pattern corresponding to the feature with the largest number may be output to the determination unit 34. For example, when a plurality of reference patterns corresponding to the arrival direction are stored in the reference pattern storage unit 33, and one reference pattern is selected from them, the arrival directions of all chips included in the candidate connection pattern are confirmed. If the number of chips having the northeast arrival direction is the largest, the reference pattern corresponding to the northeast arrival direction is output to the determination unit 34. In addition, it is possible to select one reference pattern from a plurality of reference patterns according to the arrival direction (or frequency band, modulation scheme) and refer to the determination unit 34 for all of the candidate connected patterns. You may limit only when the arrival direction (or frequency band, modulation system) of a chip | tip corresponds.

In the first embodiment, f ₁ (X, Y) and f ₂ (X, Y) are defined as functions for calculating the evaluation value in the determination unit 34. However, the evaluation function is not limited to these. There are various definitions that can be made. In f ₁ (X, Y) and f ₂ (X, Y), the evaluation value is calculated using the characteristics related to the frequency. For example, the similarity such as the arrival direction and the modulation method may be reflected in the evaluation value. Further, an evaluation function fn (X, Y) corresponding to each reference pattern held in the reference pattern storage unit 33 may be defined. In the function f ₂ (X, Y), the predetermined range is defined, but this threshold value is not limited to within ± 10%, and is individually determined for each reference pattern according to the past statistical information. A threshold may be set.

  The interference separation apparatus 3 according to the first embodiment holds a plurality of reference patterns based on past statistical information, and evaluates the connection pattern with respect to the reference pattern according to the feature extraction result of the chip included in the candidate connection pattern. Since a desired signal is extracted from all connection patterns that can be candidates based on the values, the accuracy of interference separation is improved.

Embodiment 2. FIG.
In the first embodiment, the determination unit 34 extracts a desired signal based on the evaluation value of the connection pattern with respect to the reference pattern. However, the desired signal may be further extracted using a threshold value. FIG. 6 is a block diagram showing a configuration of an interference separation apparatus according to Embodiment 2 of the present invention. Hereinafter, differences from the first embodiment will be described.

  The threshold setting unit 35 outputs the threshold Th set for each reference pattern held in the reference pattern accumulating unit 33 or for each function fn (X, Y) used by the determination unit 34 to the determination unit 34. The determination unit 34 selects the best connection pattern from the connection pattern candidates output from the signal connection unit 32 based on the evaluation value of the connection pattern with respect to the reference pattern, but compares the evaluation value with the threshold Th, and the evaluation value> The best connection pattern selected only when the threshold value Th is satisfied is output as an output result. As a result, when all the evaluation values of the candidate connection patterns are small, such as when the reception signal does not include the desired signal (when the reception signal is noise), the erroneous connection pattern is output as the desired signal. Can be prevented.

  The interference separation apparatus 3 according to the second embodiment outputs the selected best connection pattern as a desired signal only when the evaluation value calculated by the determination unit 34 is larger than the threshold value Th, so that the accuracy of signal separation is further increased. improves.

3 Interference separator 31 Feature extraction means 32 Signal connection means 33 Reference pattern storage means 34 Determination means

Claims (4)

In the interference separation device that separates a desired signal that switches to a plurality of carrier frequencies for each chip from a reception signal in which a plurality of communication waves interfere,
Feature extraction means for extracting features for each chip from the received signal and outputting them as feature extraction results;
A signal connecting means for connecting a plurality of chips based on the feature extraction result and outputting all possible connection patterns;
Reference pattern storage means for holding a plurality of reference patterns according to the features;
Based on the evaluation value of the connection pattern with respect to a reference pattern corresponding to the feature extraction result of the chip included in the connection pattern, a determination unit that extracts the desired signal from all the connection patterns that can be candidates;
Interference separator with 2. The interference separation device according to claim 1, wherein the reference pattern storage unit holds the plurality of reference patterns according to at least one feature of (1) to (4).
(1) Time (2) Arrival direction (3) Frequency band (4) Modulation method   The interference determination apparatus according to claim 1, wherein the determination unit calculates an evaluation value of the connection pattern using a function corresponding to the reference pattern.   4. The crosstalk separation device according to claim 1, wherein the determination unit extracts the desired signal only when the evaluation value is larger than a threshold value. 5.

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