JP5950761B2 - Positioning device - Google Patents

Description

  The present invention relates to a positioning device that performs positioning of a radio wave source based on time difference of arrival of radio waves and frequency difference of arrival (FDOA).

  As a positioning method for an unknown radio source, there is known a method for estimating the location of a radio source from the intersection of TDOA curves by measuring a plurality of arrival time differences (TDOA) of radio waves received by a plurality of receiving sensors ( For example, refer nonpatent literature 1).

Hereinafter, an overview of TDOA positioning will be described with reference to FIG. Here, in order to simplify the explanation, two-dimensional positioning is assumed. In this case, at least three receiving sensors are required. When the radio wave source transmits radio waves, the distances from the radio wave source to the receiving sensor are different, so that the receiving sensors arrive at different times. In TDOA positioning, a radio wave source is measured using information on the difference between sensors at these times, that is, time difference of arrival (TDOA). In TDOA positioning, these time differences (TDOA) are measured by TDOA correlation calculation. The TDOA correlation calculation can be expressed by the following equation.

Next, using the obtained TDOA ₁₃ and TDOA ₂₃ , the following simultaneous equations are solved. x _TGT = [x _TGT y _TGT ] Let ^{T be} a two-dimensional position vector of an unknown radio source. Moreover, the position vector of each receiving sensor is referred to as x ₁ , x ₂ , x ₃ . x ₁ , x ₂ and x ₃ are known. Since x _TGT to be obtained by positioning is a two-dimensional vector, there are two unknowns of simultaneous equations. On the other hand, one simultaneous equation can be established for each TDOA. Therefore, the position of the radio wave source can be evaluated by solving the following two simultaneous equations for x _TGT .

Delosme, J., Morf, M., and Friedlander, B. “Source location from time differences of arrival: Identifiability and estimation”, Acoustics, Speech, and Signal Processing, IEEE International Conference on ICASSP, Volume: 5, Page (s) : 818-824, 1980.

  In a positioning method using radio wave arrival time difference (TDOA), a plurality of reception sensors are used, correlation calculation is performed between signals of each reception sensor pair, and TDOA is measured by detecting a correlation peak. However, as shown in FIG. 2, when a plurality of signals are mixed and incident, a correlation peak is erroneously detected due to low reception sensitivity from a specific signal at a certain reception sensor or the influence of receiver noise. In this case, a plurality of correlation peaks (TDOA) having different numbers depending on the reception sensor pair are obtained. FIG. 2 shows a case where two-pair TDOA positioning with three sensors is assumed and correlation calculation is performed with two sensor pairs.

in this case,
(1) The number of signals received in common by both receiving sensor pairs is unknown.
(2) The TDOA of the signal received in common by both receiving sensor pairs is unknown, and the TDOA pairing between the receiving sensor pairs is also unknown.

  The above (1) indicates that positioning is not possible because the number of TDOA simultaneous equations is insufficient if the signals are not received in common by both receiving sensor pairs, for example, if only one sensor pair is used. means. In addition, if the positioning calculation is performed while the pairing in (2) is unknown, positioning will be performed with a brute force pair, as shown in FIG. 3, in addition to the positioning position obtained by correct pairing. There arises a problem that a position measured by incorrect pairing appears as a false image. A in FIG. 3 indicates a false image.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a positioning device that can eliminate false images due to brute force pairing.

The positioning device according to the present invention is a positioning device for positioning a radio wave source using a time difference of arrival (TDOA) of radio waves received by three or more receiving sensors, in order to measure the time difference of arrival of radio waves between the receiving sensors. When the TDOA correlation calculation is performed between the reception signals of each reception sensor pair, a TDOA having a plurality of correlation peaks is obtained, and when the number of correlation peaks differs for each reception sensor pair, different receptions in the two reception sensor pairs Calculates the TDOA inner product matrix whose elements are the product of the inner signals of the sensor's received signal shifted by TDOA, calculates the eigenvalues of the symmetrized TDOA inner product matrix, and calculates the number of eigenvalues greater than a predetermined threshold. Using the inner product matrix and the signal number estimation means that uses the number as an estimate of the number of signals received in common by the two receiving sensor pairs, A pair of correlation peaks obtained by each correlation calculation is obtained so that one TDOA is not paired with a plurality of different TDOAs and the sum of the sizes of the inner product matrix elements is increased. Is paired with TDOA pairs obtained from the same radio wave source.

In the positioning apparatus of the present invention, when a TDOA having a plurality of correlation peaks is obtained and the number of correlation peaks is different for each reception sensor pair, the received signals of the different reception sensors in the two reception sensor pairs are shifted by TDOA and the inner product is obtained. The TDOA inner product matrix with the values as elements is calculated, the eigenvalues of the symmetrized TDOA inner product matrix are calculated, the number of eigenvalues larger than a predetermined threshold is calculated, and the number is common to the two receiving sensor pairs. By using the signal number estimation means for estimating the number of received signals and the inner product matrix, the same TDOA is not redundantly paired with a plurality of different TDOAs, and the elements of the inner product matrix A pair of correlation peaks obtained by each correlation calculation is calculated so that the sum of the magnitudes becomes large, and this is set as a pair of TDOAs obtained from the same radio wave source. Therefore, it is possible to eliminate false images caused by pairing with brute force.

It is explanatory drawing which shows the outline | summary of TDOA positioning. It is explanatory drawing when the correlation peak from which a number differs is obtained by the receiving sensor pair in the conventional TDOA positioning. It is explanatory drawing which shows the false image in the conventional TDOA positioning. It is a block diagram which shows the positioning apparatus by Embodiment 1 of this invention. It is explanatory drawing which shows the example of arrangement | positioning of the radio wave source and reception sensor in the positioning apparatus by Embodiment 1 of this invention. It is explanatory drawing of the correlation calculation result in the example of arrangement | positioning of FIG. Is an explanatory view showing the eigenvalues of S _T ^H S _T in the positioning apparatus according to Embodiment 1 of the present invention. It is explanatory drawing which shows the concept of the positioning apparatus by Embodiment 2 of this invention. It is explanatory drawing which shows the concept of the positioning apparatus by Embodiment 3 of this invention. It is a block diagram which shows the positioning apparatus by Embodiment 3 of this invention. It is explanatory drawing which shows the concept of the positioning apparatus by Embodiment 4 of this invention. It is a block diagram which shows the positioning apparatus by Embodiment 4 of this invention. It is a block diagram which shows the positioning apparatus by Embodiment 5 of this invention. It is a block diagram which shows the positioning apparatus by Embodiment 6 of this invention.

Embodiment 1 FIG.
FIG. 4 is a block diagram showing a positioning apparatus according to Embodiment 1 of the present invention.
4 includes reception sensors Rx1 to Rx3, reception units 1a to 1c, TDOA correlation calculation units 2a and 2b, peak detection units 3a and 3b, a TDOA inner product matrix calculation unit 4, a signal number estimation unit 5, and a TDOA pair. A ring unit 6 and TDOA positioning calculation units 7a and 7b are provided. The reception sensors Rx1 to Rx3 are sensors that are disposed at three locations and receive radio waves from a radio wave source. The receiving units 1a to 1c are arithmetic units that receive reception signals from the receiving sensors Rx1 to Rx3 and perform analog / digital conversion by an A / D conversion unit (not shown). The peak detection units 3a and 3b are processing units that detect correlation peaks output from the TDOA correlation calculation units 2a and 2b. The TDOA inner product matrix calculation unit 4 is a calculation unit for obtaining a TDOA inner product matrix based on the correlation peak values detected by the peak detection units 3a and 3b. The signal number estimation unit 5 is a processing unit that estimates the number of signals based on the result of the inner product matrix of the TDOA inner product matrix calculation unit 4. The TDOA inner product matrix calculation unit 4 and the signal number estimation unit 5 constitute a signal number estimation unit.

  The TDOA pairing unit 6 is a pairing unit that pairs the TDOAs obtained from the respective reception sensor pairs with each other from the same radio wave source. The TDOA positioning calculation units 7a and 7b are calculation units that perform TDOA positioning calculation using the TDOA whose pairing is determined by the TDOA pairing unit 6.

ここでは、受信信号ｘ_１及びｘ_３のペアでは２つのＴＤＯＡ，受信信号ｘ_２とｘ_３のペアでは３つのＴＤＯＡが得られた例を示している。また、図４においても、ピーク検出部３ａからは２つ、ピーク検出部３ｂからは３つのピークが検出された場合を矢印の本数で示している。 Next, the operation of the positioning device configured as described above will be described.
First, the reception signals x ₁ , x ₂ , x ₃ obtained by the reception sensors Rx ₁ , Rx ₂ , Rx ₃ arranged in three places are discrete signals discretized by the A / D converter in the reception units ₁ a to ₁ c, that is, , X _i = x _i (t _k ) k = 0,..., K−1, i = 1, 2, 3 Here, t _k is the k-th sample time, K is the total number of samples. Then TDOA correlation calculation unit 2a, in 2b, a pair of the received signals _{x 1} and _{x 2,} and a pair of a received signal _{x 2} and _{x 3,} the TDOA correlation calculation shown in equation (1) and (2) Suppose that the following TDOA is obtained.

Here, an example is shown in which two TDOAs are obtained for the pair of received signals x ₁ and x ₃ and _three TDOAs are obtained for the pair of received signals x ₂ and x ₃ . Also in FIG. 4, the number of arrows indicates the case where two peaks are detected from the peak detector 3a and three peaks are detected from the peak detector 3b.

The TDOA correlation calculation, TDOA is obtained based on the _{x 3.} That is, it can be considered that the time delay of x ₁ and x ₂ relative to the reception time of x ₃ is obtained. For this reason, when x ₁ and x ₂ are shifted in time by the respective TDOA and the inner product is calculated, in the case of a correct TDOA pair, a signal in which both times coincide is obtained. Therefore, a large inner product value is obtained. On the other hand, when the pair is not a correct TDOA pair, the signals are inconsistent in time, so the inner product value is a very small value. Attention to this property, with TDOA inner product matrix calculator 4 calculates the following TDOA inner product matrix _{S T.}

ここで、ＤＦＴは離散フーリエ変換、ＩＤＦＴは逆離散フーリエ変換である。また、ｆ_ｍは、周波数領域での第ｍ周波数ビンの周波数である。 A signal x (t _k −τ) _obtained by shifting the signal x (t _k ) on the time axis by an arbitrary time τ can be calculated by the following equation.

Here, DFT is discrete Fourier transform, and IDFT is inverse discrete Fourier transform. Further, f _m is the frequency of the m frequency bins in the frequency domain.

Next, the signal number estimation unit 5 calculates the value of the S _T ^H S _T eigenvalue. The number of large eigenvalues is the number of signals. For example, threshold determination can be used for determination by size. Or may simply a number larger elements threshold TDOA inner product matrix S _T as the number of signals.
For example, when two correlation peaks are obtained with CCF _{x1, x3} (τ) and three correlation peaks are obtained with CCF _{x2, x3} (τ), the TDOA inner product matrix S is a matrix with the following 2 rows and 3 columns. Here, a and b indicate a certain large value, which means that a large inner product value is obtained. The other 0 means that a small inner product value is obtained. Actually, it is not 0 but some small value, but here it is set to 0 in order to simplify the notation. In equation (11), the number of large eigenvalues is clearly 2, and this is the signal number estimation. Thus, the number of signals can be estimated by calculating the eigenvalue of S _T ^H S _T and counting the number that exceeds a certain threshold.

The same way, for _{example, CCF x1, x3 (τ)} with three correlation _peaks, if two obtained correlation peak at _{CCF x2, x3 (τ),} S T is less 3 2 matrix Therefore, in this case, since the total number of large eigenvalues is 2, the number of signals is estimated to be 2.

Next, the operation of the positioning apparatus of the first embodiment will be further described using numerical examples.
FIG. 5 shows an example of arrangement of radio wave sources and reception sensors, FIG. 6 shows an example of correlation calculation results, and FIG. 7 shows a diagram in which eigenvalues of S _T ^H S _T are arranged in ascending order.
As shown in FIG. 5, in this example, it is assumed that there are three reception sensors Rx1, Rx2, and Rx3 and two radio wave sources Tx1 and Tx2. Therefore, ideally, two correlation peaks should occur in the correlation calculation of both the receiving sensor pairs of CCF _{x1, x3} (τ) and CCF _{x2, x3} (τ). However, as shown in FIG. 6, three correlation peaks are obtained for CCF _{x1, x3} (τ), and four correlation peaks are obtained for CCF _{x2, x3} (τ).
In such a situation, the positioning device of the present embodiment first estimates the number of signals obtained in common by both receiving sensor pairs. FIG. 7 shows a state in which eigenvalues of S _T ^H S _T are calculated and arranged in ascending order in order to estimate the number of signals. Since two large eigenvalues are obtained as shown in FIG. 7, it can be determined that there are two waves.

上記の解が、両受信センサペア間でのＴＤＯＡペアリング結果となる。 Next, since the number of signals has been estimated, the TDOA pairing unit 6 identifies the TDOA of the signal received in common by both receiving sensor pairs, and performs TDOA pairing between the receiving sensor pairs. Here, the estimated number of signals is called Jn. Focusing on each element of the TDOA inner product matrix S _T, in the TDOA pair commonly received signal in both receiving sensor pairs, with large values. Using this property, the TDOA pairing unit 6 pays attention to a pair of τ that has a large inner product value. From the elements of TDOA inner product matrix calculating unit TDOA inner product matrix calculated in 4 S _T, to be consistent, i.e., consistent as the same tau _i is paired redundantly in two or more different tau _j Thus, the (τ _i , τ _j ) pair (i = 1, 2 j = a, b, c) that maximizes the sum of the absolute values of the Jn elements is selected. It becomes an optimization problem of the following equation.

The above solution is a TDOA pairing result between the two receiving sensor pairs.

この場合、下線を引いた２つの要素の組み合わせで、式（１３）が最大であるので、ＴＤＯＡ_１３（１）とＴＤＯＡ_２３（４）がペアであり（検出ピークが、２５．１４４０４０［μｓｅｃ］，６５．０３７５０３［μｓｅｃ］），また、ＴＤＯＡ_１３（２）とＴＤＯＡ_２３（１）がペアであり（検出ピークが、−６４．０９６７６１［μｓｅｃ］，−４５．３８７４９８［μｓｅｃ］）、という結果が得られた。これは、図６に示す正解と同じ値であり、正しくペアリングができていることがわかる。 In the signal number estimation process described above, since it is determined that there are two waves, two combinations that maximize the sum are selected from the elements of the matrix abs (S _T ) so as not to contradict each other. Here, abs (S _T ) is a matrix having as elements the absolute value (size) of each element of the TDOA inner product matrix S _T. The matrix abs (S _T ) is Here, normalization is performed so that the maximum element is 1.

In this case, since the expression (13) is the maximum in the combination of two underlined elements, TDOA ₁₃ (1) and TDOA ₂₃ (4) are a pair (the detection peak is 25.144040 [μsec]). 65.037503 [μsec]), and TDOA ₁₃ (2) and TDOA ₂₃ (1) are in pairs (detection peaks are −64.040961 [μsec] and −45.387498 [μsec]). was gotten. This is the same value as the correct answer shown in FIG. 6, and it can be seen that pairing is correctly performed.

  Finally, the TDOA positioning calculation units 7a and 7b solve the simultaneous equations shown in the equations (3) and (4) by using the TDOA for which the pairing is determined.

  As described above, according to the positioning device of the first embodiment, in the positioning device that measures the radio wave source using the arrival time difference (TDOA) of radio waves received by three or more receiving sensors, When TDOA correlation calculation is performed between the reception signals of each reception sensor pair in order to measure the difference in arrival time of radio waves, a plurality of TDOAs are obtained, and the number of reception sensor pairs is different when the number is different for each reception sensor pair. Based on the number of signals estimated by the number-of-signals estimation means and the number-of-signals estimated by the number-of-signals estimation means, the TDOA obtained by each receiving sensor pair is paired with those from the same radio wave source. Therefore, it is possible to eliminate a false image caused by considering pairing with brute force as in the conventional method.

  Further, according to the positioning apparatus of the first embodiment, the signal number estimation means calculates the TDOA inner product matrix, calculates the eigenvalue of the matrix or the symmetrized matrix, and calculates the eigenvalue larger than a predetermined threshold. Since the number is calculated and the number is used as the estimated value of the number of signals, the number of signals can be reliably estimated.

  Further, according to the positioning apparatus of Embodiment 1, the pairing means uses the TDOA inner product matrix so that the same TDOA is not paired with a plurality of different TDOAs, and the TDOA inner product matrix Since the TDOA pair obtained by each correlation calculation is obtained so that the sum of the element sizes becomes large, and this is made the TDOA pair obtained from the same radio wave source, an accurate pairing result Can be obtained.

式（１５）を用いることにより、実施の形態１と同様に、信号数推定及びペアリングを行うことができる。 Embodiment 2. FIG.
In the first embodiment, the TDOA inner product matrix calculator 4, TDOA inner product matrix _{S T} is, ₁ tau signals _{x 1} and _{x 2,} respectively, tau ₂ and tau _a, tau _b, after by only time shift tau _c, It was obtained by calculating the inner product. In contrast, in the second embodiment, as a method for determining the TDOA inner product matrix _{S T,} implemented _{x 1} and the correlation calculation _{CCF x1} of _{x 2, x2 (τ),} τ 1 -τ a, τ 1 -τ _b , τ ₁ −τ _c , τ ₂ −τ _a , τ ₂ −τ _b , and τ ₂ −τ _c use the value of CCF _{x1, x2} (τ), that is, TDOA at the value of the difference of the combination of each TDOA by reading the correlation values from the calculation results of the _{CCF x1, x2 (τ),} can be obtained the elements of TDOA inner product matrix _{S T.}
FIG. 8 is a conceptual diagram of the second embodiment. For example, Expression (7) is obtained by the following Expression (15).

By using Expression (15), signal number estimation and pairing can be performed as in the first embodiment.

  As described above, according to the positioning apparatus of the second embodiment, when there are three reception sensors, the signal number estimation unit calculates the third reception sensor pair (for example, Rx1) in order to calculate the TDOA inner product matrix. , Rx3, and Rx2 and Rx3 receive sensor pairs, the third receive sensor pair performs TDOA correlation calculation between Rx1 and Rx2), and is obtained with the receive sensor pairs Rx1, Rx3, Rx2, and Rx3 Since the TDOA correlation values of Rx1 and Rx2 in the difference values between a plurality of TDOAs are read and used as the elements of the TDOA inner product matrix, reliable signal number estimation and pairing are performed as in the first embodiment. It can be performed.

Embodiment 3 FIG.
In the first and second embodiments, the case where the number of reception sensors is three has been described. However, the present invention is applicable even when there are four or more reception sensors. FIG. 9 is a conceptual diagram of the present embodiment, and FIG. 10 is a configuration diagram of the positioning device of the present embodiment.

For example, when four reception sensors are used, the TDOA obtained by CCF _{x1, x2} (τ) and CCF _{x2, x3} (τ) are applied by the reception sensors Rx1 and Rx2, Rx2 and Rx3 using the concept of daisy-chaining. It is possible to estimate the number of TDOA signals obtained in step 2) and to perform pairing. Subsequently, it is possible to estimate and pair the number of signals of TDOA obtained by CCF _{x2, x3} (τ) and TDOA obtained by CCF _{x3, x4} (τ) by applying Rx2 and Rx3 and Rx3 and Rx4. . Therefore, signal number estimation and TDOA pairing of CCF _{x1, x2} (τ), CCF _{x2, x3} (τ) and CCF _{x3, x4} (τ) have been performed. In this way, TDOA signal number estimation and pairing are possible even with four or more receiving sensors.

  In the positioning device shown in FIG. 10, Rx1 to Rx4 are four receiving sensors, and the receiving units 1a to 1d are receiving units for inputting signals from the receiving sensors Rx1 to Rx4, and these are the first embodiment shown in FIG. It is the same as that of the structure. Further, the signal number estimation and pairing units 10a and 10b are processing units corresponding to the TDOA correlation calculation units 2a and 2b to TDOA pairing unit 6 shown in FIG. 4, and their functions are TDOA correlation calculation units 2a and 2b. -Same as the TDOA pairing unit 6. The integration processing unit 11 is a processing unit that obtains a final pairing result based on the signal number estimation and processing results of the pairing units 10a and 10b. The TDOA positioning calculation units 7a and 7b have the same configuration as that shown in FIG.

In the positioning device configured as described above, in the signal number estimation and pairing units 10a and 10b, CCF _{x1, x2} (τ) in the TDOA correlation calculation units 2a and 2b and the peak detection units 3a and 3b shown in FIG. Τ ₁ , τ ₂ , and CCF _{x2, x3} (τ), and τ _a , τ _b are obtained in the processing up to the TDOA pairing unit 6, (τ ₁ , τ _a ), (τ ₂ , established pairs tau _b) is _{likewise, CCF x2, x3} (tau) in tau _a, tau _{b, and, Oh} tau in _{CCF x3, x4} (tau), if _{the had} tau has been obtained, ( τ _{a, Oh} τ), and it was established pairs (τ _b, τ _stomach). In this case, the integration processing unit 11, are obtained by commonly TDOA, in this case, by focusing on the tau _a, tau _{b, finally, (τ 1, τ a,} τ _Oh), (tau _1, get τ _b, the pairing of τ _stomach).

For example, in the case of Rx1, Rx2, Rx2, and Rx3, following the previous embodiment, the sensor that exists in common in both sensor pairs is the reference, and in this case, Rx2 is the reference. Therefore, originally, CCF _{x1, x2} (τ) and CCF _{x3, x2} (τ) should be written instead of CCF _{x1, x2} (τ) and CCF _{x2, x3} (τ), but CCF _{x1, x2} Since (τ) and CCF _{x3, x2} (−τ) are the same, only the sign of the obtained TDOA is changed. Therefore, if the processing is performed while paying attention to this point, there is no problem in either notation.

  As described above, according to the positioning apparatus of the third embodiment, the signal number estimating means and the pairing means, when there are four or more receiving sensors, the first receiving sensor, the second receiving sensor, and the second receiving sensor, The number of signals is estimated and paired by the second receiving sensor and the third receiving sensor, and then the number of signals is similarly determined by the second receiving sensor and the third receiving sensor, and the third receiving sensor and the fourth receiving sensor. By performing estimation and pairing, and sequentially performing this up to the last reception sensor, the number of signals received in common by all reception sensors and a plurality of TDOAs obtained for each reception sensor pair can be obtained from the same radio wave source. Since the pairing is performed as the TDOA, the same effects as those of the first embodiment can be obtained even when there are four or more receiving sensors.

Embodiment 4 FIG.
Embodiment 4 shows an example applicable even when there are four or more reception sensors. FIG. 11 is a conceptual diagram of the present embodiment, and FIG. 12 is a configuration diagram of the positioning device of the present embodiment.

As shown in FIG. 11, when four receiving sensors are used, a certain receiving sensor, for example, Rx4, Rx1, Rx4, Rx2, and Rx4 are applied, and TDOA obtained by CCF _{x1, x4} (τ), CCF _The number of signals of TDOA obtained by _{x2, x4} (τ) and pairing can be performed. Subsequently, it is possible to estimate and pair the number of signals of TDOA obtained by CCF _{x2, x4} (τ) and TDOA obtained by CCF _{x3, x4} (τ) by applying Rx2 and Rx4 and Rx3 and Rx4. . Therefore, signal number estimation and TDOA pairing of CCF _{x1, x4} (τ), CCF _{x2, x4} (τ), and CCF _{x3, x4} (τ) are performed. In this way, TDOA signal number estimation and pairing are possible even with four or more receiving sensors.

  The positioning device shown in FIG. 12 includes four receiving sensors Rx1 to Rx4, receiving units 1a to 1d, signal number estimation and pairing units 10a and 10b, an integration processing unit 11, and TDOA positioning calculation units 7a and 7b. The basic configuration is the same as the configuration of the third embodiment shown in FIG.

In the positioning apparatus configured in this way, the signal number estimation and pairing units 10a and 10b have CCF _{x1, x4} (τ) in the TDOA correlation calculation units 2a and 2b and the peak detection units 3a and 3b shown in FIG. in tau _1, tau ₂ and _{CCF x2, x4} (τ) in tau _a, if tau _b is obtained, the processing up to TDOA pairing unit _{6, (τ 1, τ a} ), (τ 2, τ _b) a pair is established, _{similarly, CCF x2, x4} (τ) in tau _a, tau _{b, and, Oh} tau in _{CCF x3, x4 (τ), when had} tau has been obtained, (tau _a , τ _Oh), and was established pairs (τ _b, τ _stomach). In this case, the integration processing unit 11, are obtained by commonly TDOA, in this case, by focusing on the tau _a, tau _{b, finally, (τ 1, τ a,} τ _Oh), (tau _1, get τ _b, the pairing of τ _stomach).

  As described above, according to the positioning apparatus of the fourth embodiment, the signal number estimating means and the pairing means, when there are four or more reception sensors, use the specific reception sensor as the reference reception sensor and perform the first reception. The number of signals is estimated and paired by the sensor and the reference receiving sensor, the second receiving sensor and the reference receiving sensor, and then the number of signals is estimated by the second receiving sensor and the reference receiving sensor, and the third receiving sensor and the reference sensor. And performing pairing, and performing all of the receiving sensors other than the reference sensor, it is possible to estimate the number of signals received in common by all the receiving sensors and the plurality of TDOAs obtained for each receiving sensor pair. Since pairing is performed as the TDOA of the radio wave source, the same effect as in the first embodiment can be obtained even if there are four or more reception sensors.

Embodiment 5 FIG.
Although the TDOA positioning has been described in the above first to fourth embodiments, the present invention can also be applied to Doppler frequency difference (FDOA) frequency positioning, which will be described as a fifth embodiment.

ここで、ｆは周波数である。この場合、ＴＤＯＡ内積行列Ｓ_Ｔの代わりに、ＦＤＯＡ内積行列Ｓ_Ｆを計算する必要がある。ＴＤＯＡでは時間シフトさせた信号を用いていたのに対し、ＦＤＯＡでは、周波数シフトさせた信号を用いる。信号ｘ（ｔ_ｋ）を、周信号数軸上で任意の周信号数ｆだけシフトさせた信号は、次式で計算できる。

例えば、ＣＣＦ_{ｘ１，ｘ３}（ｆ）でｆ_１，ｆ_２、ＣＣＦ_{ｘ２，ｘ３}（ｆ）でｆ_ａ，ｆ_ｂ，ｆ_ｃが得られたとすると、式（７）のＴＤＯＡ内積行列Ｓは、ＦＤＯＡ内積行列となり、次式となる。

上記式（１９）を用いれば、ＴＤＯＡの場合と同様に、信号数推定、及び、ＦＤＯＡのペアリングが可能である。 In the fifth embodiment, FDOA correlation is used instead of TDOA. This is defined by:

Here, f is a frequency. In this case, instead of TDOA inner product matrix _{S T,} it is necessary to calculate the FDOA inner product matrix _{S F.} In TDOA, a time-shifted signal is used, while in FDOA, a frequency-shifted signal is used. A signal _obtained by shifting the signal x (t _k ) by an arbitrary number of peripheral signals f on the peripheral signal number axis can be calculated by the following equation.

For _{example, CCF x1,} x3 (f) at _{f 1, f 2, CCF x2} , x3 (f) at _{f a, f b,} When _{f c} is obtained, TDOA inner product matrix S of the formula (7), FDOA The inner product matrix is given by

If the above equation (19) is used, signal number estimation and FDOA pairing are possible as in the case of TDOA.

  FIG. 13 is a configuration diagram illustrating the positioning apparatus according to the fifth embodiment. The positioning device according to the fifth embodiment includes reception sensors Rx1 to Rx3, reception units 1a to 1c, FDOA correlation calculation units 20a and 20b, peak detection units 3a and 3b, an FDOA inner product matrix calculation unit 40, a signal number estimation unit 5, and an FDOA. A pairing unit 60 and FDOA positioning calculation units 70a and 70b are provided. Here, the receiving sensors Rx1 to Rx3, the receiving units 1a to 1c, the peak detecting units 3a and 3b, and the signal number estimating unit 5 are the same as the configuration of the first embodiment shown in FIG. The FDOA correlation calculation units 20a and 20b replace the TDOA correlation calculation units 2a and 2b in FIG. 4, and the peak detection units 3a and 3b perform peak detection on the FDOA correlation in the FDOA correlation calculation units 20a and 20b. The FDOA inner product matrix calculation unit 40 is a calculation unit corresponding to the TDOA inner product matrix calculation unit 4 in FIG. 4 and performs the calculation of the above equation (19). The FDOA pairing unit 60 follows the processing in the case of TDOA based on the result of Expression (19). The FDOA positioning calculation units 70a and 70b perform positioning calculation by the least square method using the following equations (20) and (21).

ここで、λは電波源の信号の波長、ｖ_ＴＧＴは電波源の移動速度ベクトルであり、既知とする。この場合も、連立方程式の数は２、未知変数ｘ_ＴＧＴの数も２である。よって、未知変数ｘ_ＴＧＴについて解くことができる。上記方程式は、勾配法など、公知の手法で解くことができるので、詳細は割愛する。
なお、実施の形態１〜４で説明した考え方は、ＴＤＯＡをＦＤＯＡに入れ替えれば、そのままＦＤＯＡにも踏襲できる。考え方は明らかであるので、その詳細は省略する。

Here, λ is the wavelength of the signal of the radio wave source, and v _TGT is the moving speed vector of the radio wave source, which is known. In this case, the number of simultaneous equations is 2, and the number of unknown variables x _TGT is 2. Therefore, the unknown variable x _TGT can be solved. Since the above equation can be solved by a known method such as a gradient method, the details are omitted.
In addition, if the idea demonstrated in Embodiment 1-4 is replaced with TDOA to FDOA, it can follow FDOA as it is. Since the concept is clear, the details are omitted.

  As described above, according to the positioning device of the fifth embodiment, in the positioning device that measures the radio wave source using the Doppler frequency difference (FDOA) of radio waves received by three or more receiving sensors, When the FDOA correlation calculation is performed between the reception signals of each reception sensor pair in order to measure the arrival time difference between the reception sensor pairs, a plurality of FDOAs are obtained and the number of receptions is different for each reception sensor pair. Based on the number of signals estimated by the signal number estimation means and the signal number estimation means for estimating the number of signals received by the sensor pair, the FDOA obtained by each reception sensor pair is paired with those from the same radio wave source. Since the pairing means for performing the ring is provided, it is possible to eliminate a false image caused by considering pairing as a brute force as in the conventional method.

Embodiment 6 FIG.
The present invention can be applied not only to the TDOA positioning described in Embodiments 1 to 4 or the FDOA positioning described in Embodiment 5 but also to positioning using both TDOA and FDOA. Will be described below as a fifth embodiment.

この場合、ＴＤＯＡとＦＤＯＡの２次元相関により、ＴＤＯＡ及びＦＤＯＡを計算し、受信信号を時間方向及び周波数方向の両方にシフトさせてＴ／ＦＤＯＡ内積行列Ｓ_ＴＦを計算すればよい。例えば、ＣＣＦ_{ｘ１，ｘ３}（τ，ｆ）で（τ_１，ｆ_１），（τ_２，ｆ_２）が得られ、ＣＣＦ_{ｘ２，ｘ３}（τ，ｆ）で（τ_ａ，ｆ_ａ），（τ_ｂ，ｆ_ｂ），（τ_ｃ，ｆ_ｃ）が得られた場合、以下の２×３行列をＴ／ＦＤＯＡ内積行列は次式となる。

In the case of positioning using TDOA and FDOA, the correlation calculation is a two-dimensional correlation in the time direction and the frequency direction. First, the correlation calculation formula of TDOA and FDOA is given by the following formula.

In this case, TDOA and FDOA are calculated based on the two-dimensional correlation between TDOA and FDOA, and the received signal is shifted in both the time direction and the frequency direction to calculate the T / FDOA inner product matrix S _TF . For _{example, CCF x1, x3 (τ,} f) at _{(τ 1, f 1),} (τ 2, f 2) are _{obtained, CCF x2, x3 (τ,} f) at _{(τ a, f a),} ( When τ _b , f _b ) and (τ _c , f _c ) are obtained, the T / FDOA inner product matrix of the following 2 × 3 matrix is as follows.

  FIG. 14 is a configuration diagram illustrating the positioning apparatus according to the sixth embodiment. The positioning device of the sixth embodiment includes reception sensors Rx1 to Rx3, reception units 1a to 1c, T / FDOA correlation calculation units 21a and 21b, peak detection units 3a and 3b, T / FDOA inner product matrix calculation unit 41, and signal number estimation. Unit 5, a T / FDOA pairing unit 61, and T / FDOA positioning calculation units 71a and 71b. Here, the T / FDOA correlation calculation units 21a and 21b, the T / FDOA dot product matrix calculation unit 41, the T / FDOA pairing unit 61, and the T / FDOA positioning calculation units 71a and 71b are respectively the TDOA correlation calculation units in FIG. 2a, 2b, the TDOA inner product matrix calculation unit 4, the TDOA pairing unit 6, and the TDOA positioning calculation units 7a, 7b. The other configurations are the same as those in FIG.

In the sixth embodiment, the TDOA correlation calculation units 2a and 2b in FIG. 4 are replaced with T / FDOA correlation calculation units 21a and 21b to perform two-dimensional correlation calculation of TDOA and FDOA. The peak detectors 3a and 3b perform peak detection for the two-dimensional correlation. The T / FDOA inner product matrix calculation unit 41 calculates the above equation (24). The T / FDOA pairing unit 61 performs processing based on the concept of the TDOA pairing unit 6 based on the equation (24). Finally, the T / FDOA positioning calculation units 71a and 71b perform positioning calculation by the least square method using the TDOA formulas (3) and (4) and the FDOA formulas (20) and (21). . In this case, since the number of simultaneous equations is four, if v _TGT is treated as an unknown variable, both the radio source position x _TGT and the velocity v _TGT are treated as unknown variables (total of four unknown variables) and estimated. Can do. Since the solution can be solved by a known technique such as a gradient method, the description is omitted.
In addition, if the idea demonstrated in Embodiment 1-4 is replaced with T / FDOA, T / FDOA can be followed as it is. Since the concept is clear, the details are omitted.

  As described above, according to the positioning apparatus of the sixth embodiment, the radio wave source is positioned using the arrival time difference (TDOA) of radio waves received by three or more reception sensors and the Doppler frequency difference (FDOA). When the TDOA and FDOA correlation calculation is performed between the reception signals of each reception sensor pair in order to measure the arrival time difference of the radio wave between the reception sensors, a plurality of TDOA and FDOA are obtained and When the number is different for each reception sensor pair, the signal number estimation means for estimating the number of signals received by each reception sensor pair, and the number of signals estimated by the signal number estimation means were obtained for each reception sensor pair. Pairing TDOA and FDOA from the same radio wave source with pairing means for pairing with each other. It is possible to eliminate the false image due to be considered.

  In the present invention, within the scope of the invention, any combination of the embodiments, or any modification of any component in each embodiment, or omission of any component in each embodiment is possible. .

  Rx1-Rx3 reception sensor, 1a-1d reception unit, 2a, 2b TDOA correlation calculation unit, 3a, 3b peak detection unit, 4 TDOA inner product matrix calculation unit, 5 signal number estimation unit, 6 TDOA pairing unit, 7a, 7b TDOA Positioning calculation unit, 10a, 10b Signal number estimation and pairing unit, 11 Integration processing unit, 20a, 20b FDOA correlation calculation unit, 21a, 21b T / FDOA correlation calculation unit, 40 FDOA inner product matrix calculation unit, 41 T / FDOA inner product Matrix calculation unit, 60 FDOA pairing unit, 61 T / FDOA pairing unit, 70a, 70b FDOA positioning calculation unit, 71a, 71b T / FDOA positioning calculation unit.

Claims (12)

In a positioning device for positioning a radio wave source using a time difference of arrival (TDOA) of radio waves received by three or more receiving sensors,
When TDOA correlation calculation is performed between the reception signals of each reception sensor pair in order to measure the arrival time difference of the radio wave between the reception sensors, a TDOA having a plurality of correlation peaks is obtained, and the number of correlation peaks is When different for each receiving sensor pair, a TDOA inner product matrix is calculated with the inner product obtained by shifting the received signals of different receiving sensors in the two receiving sensor pairs by TDOA, and the eigenvalue of the matrix obtained by symmetrizing the TDOA inner product matrix is calculated. Calculating the number of eigenvalues greater than a predetermined threshold, and setting the number as an estimated value of the number of signals received in common by the two receiving sensor pairs;
Using the inner product matrix, the same TDOA was obtained in each correlation operation so that the same TDOA was not paired with a plurality of different TDOAs and the sum of the element sizes of the inner product matrix was increased. A positioning device comprising a pairing means for obtaining a pair of correlation peaks and using this as a pair of TDOAs obtained from the same radio wave source.   The signal number estimating means performs TDOA correlation calculation between a third receiving sensor pair different from two receiving sensor pairs in order to calculate a TDOA inner product matrix when there are three receiving sensors, The positioning according to claim 1, wherein a TDOA correlation value of the third receiving sensor pair in a difference value between a plurality of TDOAs obtained by the receiving sensor pair is read, and the value is used as each element of a TDOA inner product matrix. apparatus.   When the number of reception sensors is four or more, the signal number estimation means and the pairing means estimate the number of signals and pair with the first reception sensor and the second reception sensor, and the second reception sensor and the third reception sensor. Then, the second reception sensor and the third reception sensor, and the third reception sensor and the fourth reception sensor similarly perform signal number estimation and pairing, and sequentially perform this until the last reception sensor. And performing the pairing of the TDOAs of the same radio wave source by integrating the estimation of the number of signals received in common by all reception sensors and the TDOA pairs obtained for each reception sensor pair. The positioning device according to claim 1 or claim 2.   When there are four or more reception sensors, the signal number estimation means and the pairing means use a specific reception sensor as a reference reception sensor, the first reception sensor, the reference reception sensor, the second reception sensor, and the reference The number of signals is estimated and paired by the receiving sensor, and then the number of signals is estimated and paired by the second receiving sensor and the reference receiving sensor, and the third receiving sensor and the reference receiving sensor. By performing all the receiving sensors other than the receiving sensor, the number of signals received in common by all the receiving sensors and the TDOA pair obtained for each receiving sensor pair are integrated to form a TDOA pair of the same radio wave source. The positioning device according to claim 1 or 2, wherein a ring is used. In a positioning device for positioning a radio wave source using Doppler frequency difference (FDOA) of radio waves received by three or more receiving sensors,
When the FDOA correlation calculation is performed between the reception signals of each reception sensor pair in order to measure the arrival time difference of the radio wave between the reception sensors, an FDOA having a plurality of correlation peaks is obtained, and the number of correlation peaks is When different for each receiving sensor pair, an FDOA inner product matrix is calculated, which is obtained by shifting the received signals of the different receiving sensors in the two receiving sensor pairs by FDOA and using the inner product as an element, and the eigenvalue of the matrix obtained by symmetrizing the FDOA inner product matrix is calculated. Calculating the number of eigenvalues greater than a predetermined threshold, and setting the number as an estimated value of the number of signals received in common by the two receiving sensor pairs;
By using the inner product matrix, the same FDOA is not paired with a plurality of different FDOAs, and the FDOA obtained by each correlation operation so that the sum of the sizes of the inner product matrix elements is increased. A positioning apparatus comprising: a pairing means for obtaining a pair of FDOAs obtained from the same radio wave source.   When the number of reception sensors is three, the signal number estimation means performs an FDOA correlation operation between a third reception sensor pair different from the two reception sensor pairs in order to calculate an FDOA inner product matrix. 6. The positioning according to claim 5, wherein an FDOA correlation value of the third receiving sensor pair in a difference value between a plurality of FDOAs obtained by the receiving sensor pair is read and used as each element of the FDOA inner product matrix. apparatus.   When the number of reception sensors is four or more, the signal number estimation means and the pairing means estimate the number of signals and pair with the first reception sensor and the second reception sensor, and the second reception sensor and the third reception sensor. Then, the second reception sensor and the third reception sensor, and the third reception sensor and the fourth reception sensor similarly perform signal number estimation and pairing, and sequentially perform this until the last reception sensor. And performing the pairing of the FDOAs of the same radio wave source by integrating the estimation of the number of signals commonly received by all reception sensors and the pair of FDOAs obtained for each reception sensor pair. The positioning device according to claim 5 or 6.   When there are four or more reception sensors, the signal number estimation means and the pairing means use a specific reception sensor as a reference reception sensor, the first reception sensor, the reference reception sensor, the second reception sensor, and the reference The number of signals is estimated and paired by the receiving sensor, and then the number of signals is estimated and paired by the second receiving sensor and the reference receiving sensor, and the third receiving sensor and the reference receiving sensor. By performing all of the receiving sensors other than the receiving sensor, the number of signals received in common by all the receiving sensors and the FDOA pair obtained for each receiving sensor pair are integrated to form a pair of FDOAs of the same radio wave source. The positioning device according to claim 5 or 6, wherein a ring is provided. In a positioning device for positioning a radio wave source using a time difference of arrival (TDOA) and a frequency difference of arrival (FDOA) received by three or more receiving sensors,
When TDOA and FDOA correlation calculation is performed between the reception signals of each reception sensor pair in order to measure the arrival time difference of radio waves between the reception sensors, TDOA and FDOA having a plurality of correlation peaks are obtained, and When the number of correlation peaks differs for each receiving sensor pair, the TDOA and FDOA inner product matrix is calculated with the elements obtained by shifting the received signals of the different receiving sensors in the two receiving sensor pairs by the TDOA and FDOA of each receiving sensor pair. Calculating the eigenvalues of the symmetrized TDOA and FDOA inner product matrices, calculating the number of eigenvalues larger than a predetermined threshold, and the number of signals received in common by the two receiving sensor pairs. Means for estimating the number of signals to be estimated values of
By using the inner product matrix, the same TDOA and FDOA are not paired with a plurality of different TDOA and FDOA, and each correlation operation is performed so that the sum of the sizes of the elements of the inner product matrix is increased. A positioning apparatus comprising: a pairing means for obtaining a pair of TDOA and FDOA obtained and using the pair as a pair of TDOA and FDOA obtained from the same radio wave source.   The signal number estimating means performs TDOA and FDOA correlation calculation between a third receiving sensor pair different from the two receiving sensor pairs in order to calculate a TDOA and FDOA inner product matrix when there are three receiving sensors. Reading the TDOA and FDOA correlation values of the third receiving sensor pair in the difference values between the plurality of TDOA and FDOA obtained by the two receiving sensor pairs, and using the values as the elements of the TDOA and FDOA inner product matrix The positioning device according to claim 9.   When the number of reception sensors is four or more, the signal number estimation means and the pairing means estimate the number of signals and pair with the first reception sensor and the second reception sensor, and the second reception sensor and the third reception sensor. Then, the second reception sensor and the third reception sensor, and the third reception sensor and the fourth reception sensor similarly perform signal number estimation and pairing, and sequentially perform this until the last reception sensor. By performing the estimation, the number of signals received in common by all reception sensors and the pair of TDOA and FDOA obtained for each reception sensor pair are integrated to perform TDOA and FDOA pairing of the same radio wave source. The positioning device according to claim 9 or 10, wherein the positioning device is characterized in that:   When there are four or more reception sensors, the signal number estimation means and the pairing means use a specific reception sensor as a reference reception sensor, the first reception sensor, the reference reception sensor, the second reception sensor, and the reference The number of signals is estimated and paired by the receiving sensor, and then the number of signals is estimated and paired by the second receiving sensor and the reference receiving sensor, and the third receiving sensor and the reference receiving sensor. By performing all the receiving sensors other than the receiving sensor, the number of signals received in common by all the receiving sensors and the TDOA and FDOA pairs obtained for each receiving sensor pair are integrated to obtain the TDOA of the same radio wave source. The positioning device according to claim 9 or 10, wherein pairing of the FDOA and the FDOA is performed.

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