Position estimation system and position estimation method

Abstract

The present invention achieves, in a bistatic or multi-static system, a position estimation system and a position estimation method capable of improving the accuracy of estimating the position of a target in a three-dimensional space. In a bistatic system or a multistatic system in which one or more transmission units and one or more reception units are arranged as separate from one another, this position estimation system and position estimation method estimate the position of a target in a three-dimensional space on the basis of reception signals acquired by a plurality of virtual antennas configured from combinations of a plurality of transmission antennas and a plurality of reception antennas.

Description

Location estimation system and location estimation method

[0001] The present invention relates to a location estimation system and a location estimation method.

[0002] Conventionally, in a position estimation method using a so-called bistatic or multistatic method, radio waves transmitted from a transmitter and reflected by a target are received by a receiver to estimate the position of the target (for example, Non-Patent Document 1).

[0003] O. Kanhere, S. Goyal, M. Beluri, and T. S. Rappaport, “Target Localization using Bistatic and Multistatic Radar with 5G NR Waveform”

[0004] In the above-mentioned conventional technology, distance estimation is performed as a monostatic system, and the target position is estimated in a two-dimensional plane including the transmitter, receiver, and target using the angle measured by the receiver and the known distance between the transmitter and receiver. Therefore, the accuracy of position estimation may be reduced when observing a three-dimensional space.

[0005] The present disclosure has been made in consideration of the above, and aims to realize a position estimation system and a position estimation method that can improve the accuracy of estimating the position of a target in three-dimensional space in a bistatic or multistatic system.

[0006] A position estimation system according to one aspect of the present disclosure is a bistatic or multistatic position estimation system in which one or more transmitters and one or more receivers are disposed separately from each other, the system including: a transmitter having a plurality of transmitter antennas; a receiver having a plurality of receiver antennas; and a processor that estimates a position of a target based on received signals acquired by a plurality of virtual antennas formed by combining a plurality of the transmitter antennas and a plurality of the receiver antennas, wherein the arrangement direction of two adjacently arranged transmitter antennas and the arrangement direction of two adjacently arranged receiver antennas are different from each other on a yz plane orthogonal to the x direction, and the processor The antenna includes a first distance estimation unit that estimates a distance based on monostatic operation, a first spectrum analysis unit that performs spectrum analysis of received signals from virtual antennas aligned in the y direction, a second distance calculation unit that calculates a distance based on bistatic or multistatic operation based on the analysis result by the first spectrum analysis unit, a phase correction unit that performs phase correction of a complex amplitude component of the analysis result by the first spectrum analysis unit, a second spectrum analysis unit that performs spectrum analysis of the correction result by the phase correction unit, and an angle calculation unit that calculates an azimuth angle and an elevation / depression angle based on the analysis results by the first spectrum analysis unit and the second spectrum analysis unit.

[0007] This allows for improved accuracy in estimating the position of a target in three-dimensional space in a bistatic or multistatic system.

[0008] a first spectral analysis unit that performs spectral analysis of the received signals of the virtual antennas aligned in the y direction; a second distance calculation unit that calculates the distance based on bistatic or multistatic operation based on the analysis result by the first spectral analysis unit; a second spectral analysis unit that performs spectral analysis of the complex amplitude component of the analysis result by the first spectral analysis unit; and an angle calculation unit that calculates the azimuth angle and the elevation / depression angle based on the analysis results by the first spectral analysis unit and the second spectral analysis unit.

[0009] This allows for improved accuracy in estimating the position of a target in three-dimensional space in a bistatic or multistatic system.

[0010] A position estimation method according to one aspect of the present disclosure is a position estimation method for estimating a position of a target based on received signals acquired by a plurality of virtual antennas formed by a combination of a plurality of transmitting antennas and a plurality of receiving antennas in a bistatic system or multistatic system in which one or more transmitting units and one or more receiving units are respectively arranged at a distance from each other, wherein the arrangement direction of two adjacently arranged transmitting antennas and the arrangement direction of two adjacently arranged receiving antennas are different from each other on a yz plane orthogonal to the x direction, and the position estimation method includes: a first distance estimation step of estimating a distance based on monostatic operation; a first spectral analysis step of performing a spectral analysis of the received signals of the virtual antennas arranged in the y direction; a second distance calculation step of calculating a distance based on a bistatic or multistatic operation based on a result of the analysis in the first spectral analysis step; a phase correction step of performing a phase correction on a complex amplitude component of the result of the analysis in the first spectral analysis step; a second spectral analysis step of performing a spectral analysis of the result of the correction in the phase correction step; and an angle calculation step of calculating an azimuth angle and an elevation / depression angle based on the analysis results in the first spectral analysis step and the second spectral analysis step.

[0011] This allows for improved accuracy in estimating the position of a target in three-dimensional space in a bistatic or multistatic system.

[0012] A position estimation method according to one aspect of the present disclosure is a position estimation method for estimating a position of a target based on received signals acquired by a plurality of virtual antennas formed by a combination of a plurality of transmitting antennas and a plurality of receiving antennas in a bistatic system or multistatic system in which one or more transmitting units and one or more receiving units are respectively arranged at a distance from each other, wherein the arrangement direction of two adjacently arranged transmitting antennas and the arrangement direction of two adjacently arranged receiving antennas are orthogonal to each other on a yz plane orthogonal to the x direction, and the position estimation method includes: a first distance estimation step of estimating a distance based on monostatic operation; a first spectral analysis step of performing a spectral analysis of the received signals of the virtual antennas arranged in the y direction; a second distance calculation step of calculating a distance based on bistatic or multistatic operation based on the analysis result of the first spectral analysis step; a second spectral analysis step of performing a spectral analysis of a complex amplitude component of the analysis result of the first spectral analysis step; and an angle calculation step of calculating an azimuth angle and an elevation / depression angle based on the analysis results of the first spectral analysis step and the second spectral analysis step.

[0013] This allows for improved accuracy in estimating the position of a target in three-dimensional space in a bistatic or multistatic system.

[0014] According to the present disclosure, it is possible to realize a position estimation system and a position estimation method that can improve the accuracy of estimating the position of a target in a three-dimensional space in a bistatic or multistatic system.

[0015] FIG. 1 is a block diagram showing a schematic configuration of a position estimation system according to an embodiment. FIG. 2 is a conceptual diagram showing a position vector of a target in three-dimensional space. FIG. 3 is a conceptual diagram showing position vectors of transmitting antennas and receiving antennas in three-dimensional space. FIG. 4A is a conceptual diagram showing an example of the arrangement of transmitting antennas in a position estimation system according to an embodiment. FIG. 4B is a conceptual diagram showing an example of the arrangement of receiving antennas in a position estimation system according to an embodiment. FIG. 4C is a conceptual diagram showing a virtual antenna formed by transmitting antennas and receiving antennas in a position estimation system according to an embodiment. FIG. 5 is a flowchart showing an example of a position estimation method according to an embodiment. FIG. 6 is a conceptual diagram used in a position estimation technique according to an embodiment. FIG. 7 is a block diagram showing a schematic configuration of a position estimation system according to a modified example. FIG. 8A is a conceptual diagram showing an example of the arrangement of transmitting antennas in a position estimation system according to a modified example. FIG. 8B is a conceptual diagram showing an example of the arrangement of receiving antennas in a position estimation system according to a modified example. FIG. 8C is a conceptual diagram showing a virtual antenna formed by transmitting antennas and receiving antennas in a position estimation system according to a modified example. FIG. 9 is a flowchart showing an example of a position estimation method according to a modified example. FIG. 10A is a conceptual diagram showing a first modified example of a virtual antenna. Fig. 10B is a conceptual diagram showing an example of the arrangement of transmitting antennas that constitute a virtual antenna according to a first modified example. Fig. 10C is a conceptual diagram showing an example of the arrangement of receiving antennas that constitute a virtual antenna according to the first modified example. Fig. 11A is a conceptual diagram showing a second modified example of a virtual antenna. Fig. 11B is a conceptual diagram showing an example of the arrangement of transmitting antennas that constitute a virtual antenna according to the second modified example. Fig. 11C is a conceptual diagram showing an example of the arrangement of receiving antennas that constitute a virtual antenna according to the second modified example.

[0016] Hereinafter, a location estimation system and a location estimation method according to an embodiment will be described in detail with reference to the drawings. However, the present disclosure is not limited to the embodiment.

[0017] Fig. 1 is a block diagram showing a schematic configuration of a position estimation system according to an embodiment. The position estimation system 1 according to the embodiment is a bi-static or multi-static system in which one or more transmitters 10 and one or more receivers 20 are arranged separately from each other. In the configuration shown in Fig. 1, the position estimation system 1 includes the transmitter 10, the receiver 20, and a processor 30.

[0018] In the present disclosure, the position estimation system 1 is exemplified by a bistatic radar in which the transmitter 10 and the receiver 20 are separated. However, the position estimation system 1 is not limited to this, and may be configured such that two transmitters and receivers, each having a transmitter and a receiver, are disposed separately, or may be a multistatic radar having multiple transmitters and multiple receivers. Furthermore, the present disclosure is widely applicable to configurations in which target position estimation is performed using bistatic or multistatic radar technology.

[0019] The transmitter 10 has a plurality of transmitting antennas TX[n ｔ ](n ｔ is from 1 to N ｔ transmit antenna number up to N ｔ is the total number of transmitting antennas). Specifically, in the example shown in FIG. 1, the transmitter 10 has transmitting antennas TX[1], TX[2], and TX[3]. Note that, ｔ ]total number N ｔ is not limited to 3.

[0020] The receiver 20 has a plurality of receiving antennas RX[n ｒ ](n ｒ is from 1 to N ｒ receiving antenna number up to N ｒ is the total number of receiving antennas). Specifically, in the example shown in FIG. 1, the receiving unit 20 has receiving antennas RX[1], RX[2], RX[3], and RX[4]. ｒ ]total number N ｒ is not limited to 4.

[0021] The processing unit 30 includes a first distance estimation unit 31, a first spectrum analysis unit 32, a second distance calculation unit 33, a phase correction unit 34, a second spectrum analysis unit 35, and an angle calculation unit 36. Specific processing in each component of the processing unit 30 will be described later.

[0022] 2 is a conceptual diagram showing a position vector of a target in three-dimensional space. P in FIG. 2 indicates the position of the target within the observation range of the position estimation system 1. In the present disclosure, the angle formed between the x-axis and a vector obtained by projecting the target position vector (hereinafter also referred to as a "target position vector") onto the x-y plane is defined as an "azimuth angle θ," and the angle formed between the target position vector and the vector obtained by projecting it onto the x-y plane is defined as an "elevation / depression angle φ."

[0023] FIG. 3 is a conceptual diagram showing the position vectors of the transmitting antenna and the receiving antenna in three-dimensional space.

[0024] In FIG. ｒ （ｎｒ） is the receiving antenna RX[n ｒ ]. In this disclosure, the position vector of the receiving antenna RX[n ｒ ] position vector l ｒ （ｎｒ） is defined by the following equation (1).

[0025]

[0026] Also, in FIG. ｔ （ｎｔ） is the transmit antenna TX[n ｔ ]. In this disclosure, the position vector of the transmitting antenna TX[n ｔ ] position vector l ｔ （ｎｔ） is defined by the following equation (2).

[0027]

[0028] In the three-dimensional space shown in FIG. ｒ ] the unit vector U corresponding to the angle seen from ｒ is the receiving antenna RX[n ｒ ] is the azimuth angle of the target as seen from ｒ, the elevation angle is φ ｒ is defined by the following equation (3).

[0029]

[0030] In the three-dimensional space shown in FIG. ｔ ] the unit vector U corresponding to the angle seen from ｔ is the transmit antenna TX[n ｔ ] is the azimuth angle of the target as seen from ｔ , the elevation angle is φ ｔ is defined by the following equation (4).

[0031]

[0032] Transmitting antenna TX[n ｔ ], the electromagnetic wave of wavelength λ transmitted from the target reaches the target, and then the electromagnetic wave reflected by the target is transmitted to the receiving antenna RX[n ｒ ], the phase Φ that changes depending on the propagation path is expressed by the following equation (5) as ｔ ] to the target, the phase ξ [n ｔ ] and the receiving antenna RX[n ｒ ] until the phase ξ[n ｒ ] can be expressed as the Kronecker product.

[0033]

[0034] Transmitting antenna TX[n ｔ ] to the target, the phase ξ [n ｔ ] is the transmission antenna TX[n ｔ ] position vector l ｔ （ｎｔ） and the transmitting antenna TX[n ｔ ] the unit vector U corresponding to the angle seen from ｔ Also, the signal from the target to the receiving antenna RX[n ｒ ] until the phase ξ[n ｒ ] is the transmission antenna TX[n ｔ ] position vector lｔ （ｎｔ） and the receiving antenna RX[n ｒ ] the unit vector U corresponding to the angle seen from ｒ It is calculated by the inner product of the transmitting antenna TX[n ｔ ] to the target, the phase ξ [n ｔ ], and the receiving antenna RX[n ｒ ] until the phase ξ[n ｒ ] is expressed by the following formula (6).

[0035]

[0036] Transmitting antenna TX[n ｔ ] and reflected by the target to the receiving antenna RX[n ｒ ], the received signal s[n ｔ , n ｒ ] is calculated by combining the phase Φ of the above equation (5) with the amplitude a[n ｔ , n ｒ ] can be expressed as a product.

[0037]

[0038] Fig. 4A is a conceptual diagram showing an example of the arrangement of transmitting antennas in a position estimation system according to an embodiment. Fig. 4B is a conceptual diagram showing an example of the arrangement of receiving antennas in a position estimation system according to an embodiment. Fig. 4C is a conceptual diagram showing a virtual antenna formed by transmitting antennas and receiving antennas in a position estimation system according to an embodiment.

[0039] In the example shown in FIG. 4A, the transmit antenna TX[n ｔ ] are arranged side by side in one direction (first direction) on the yz plane. ｔ ] is a distance d in the y and z directions Ａ They are arranged in a staggered manner.

[0040] In the example shown in FIG. 4B, the receiving antenna RX[n ｒ ] are arranged side by side in the y direction (second direction) on the yz plane. More specifically, the receiving antennas RX[n ｒ] is the distance d in the y direction Ａ They are arranged in a staggered manner.

[0041] In other words, multiple transmit antennas TX[n ｔ ] and the arrangement direction of the multiple receiving antennas RX[n ｒ ] are arranged in different directions. ｔ ] and multiple receiving antennas RX[n ｒ ] and a plurality of virtual antennas VX[n ｔ , n ｒ ] is configured in the shape of a parallelogram on the yz plane, as shown in FIG. 4C.

[0042] Note that the transmitting antenna TX[n ｔ ] and the arrangement of the receiving antennas RX[n ｒ The arrangement of two adjacent transmitting antennas TX[n ｔ ] and the direction in which two adjacent receiving antennas RX[n ｒ ] may be different from each other on the yz plane perpendicular to the x direction.

[0043] The processing unit 30 receives the signals from the multiple transmitting antennas TX[n ｔ ] and multiple receiving antennas RX[n ｒ ] and a plurality of virtual antennas VX[n ｔ , n ｒ ] and estimate the target position based on the received signals acquired by the above steps.

[0044] Here, as an example, the orthogonal linear coordinates of the transmitting antenna TX[1] are set to the origin coordinates (0,0,0) of the xyz space as the matrix L ｔ Also, the matrix L is defined as the orthogonal linear coordinates of the receiving antenna RX[1], which is the origin coordinate (0,0,0) of the xyz space. ｒ Define the matrix L ｔ and matrix L ｒ is expressed by the following equation (8).

[0045]

[0046] In this case, the virtual antenna VX[n ｔ , n ｒ ] for each received signal s[n ｔ , n ｒ ] is expressed by the following equation (9), the matrix S including the virtual antenna VX[n ｔ , n ｒ ] for each received signal s[n ｔ , n ｒ ] amplitude a[n ｔ , n ｒ ] and the above equation (5) showing the phase Φ.

[0047]

[0048]

[0049] Specific processing of the position estimation system 1 according to the embodiment will be described below with reference to FIGS. 5 and 6 . FIG. 5 is a flowchart illustrating an example of a position estimation method according to the embodiment. FIG. 6 is a conceptual diagram used in the position estimation technique according to the embodiment. FIG. 6 illustrates an example in which the orthogonal linear coordinates of the reception point R are set to the origin coordinates (0,0,0) of the xyz space, and the orthogonal linear coordinates of the transmission point T are set to coordinates (0,d,0) that are a distance d away in the y direction (second direction) from the origin coordinates (0,0,0) of the xyz space. That is, in the example illustrated in FIG. 6 , the transmitter 10 and the receiver 20 are arranged side by side in the y direction (second direction) and are spaced apart by the distance d. Furthermore, P illustrated in FIG. 6 indicates the position of a target within the observation range of the position estimation system 1.

[0050] In the position estimation process according to the embodiment shown in FIG. 5, the first distance estimation unit 31 estimates the distance between the virtual antenna VX[n ｔ , n ｒ ], the received signal s[n ｔ , n ｒ ] to calculate the distance r from the receiving point R. ｒ (hat) is estimated (first distance estimation processing step S100). In the present disclosure, the distance estimation operation in the first distance estimation unit 31 is also referred to as a "monostatic operation." Note that "^" shown in the formula is a symbol indicating an estimated value, and is represented as (hat) in the present text due to limitations of description.

[0051] The first distance estimation unit 31 calculates the estimated value r of the distance from the receiving point R by calculating half the value of the distance obtained by the propagation delay time of the electromagnetic wave in the propagation path of the electromagnetic wave from the transmitting point T to the receiving point R. ｒ In other words, the distance r estimated by monostatic operation is ｒ (hat) is the true value r of the distance as seen from the receiving point R, as shown in the following equation (11). ｒ and the true value r of the distance seen from the transmitting point T ｔ It is half the value obtained by adding and.

[0052]

[0053] Also, the angle η between the y-axis and the direction seen from the receiving point R ｒ Using the above, the following equation (12) is obtained by the cosine theorem.

[0054]

[0055] From the above equations (11) and (12), the true value r of the distance as seen from the transmitting point T is ｔ By eliminating, the following equation (13) is obtained.

[0056]

[0057] The first spectrum analyzer 32 analyzes the virtual antennas VX[n ｔ , n ｒ ] received signal s[n ｔ , n ｒ ] is subjected to a spectral analysis (first spectral analysis processing step S200).

[0058] Specifically, the first spectrum analysis unit 32 performs spectrum analysis processing on the received signals s[1,1], s[1,2], s[1,3], and s[1,4] of the virtual antennas VX[1,1], VX[1,2], VX[1,3], and VX[1,4].

[0059] In addition, the first spectrum analysis unit 32 performs spectrum analysis processing on the received signals s[2,1], s[2,2], s[2,3], and s[2,4] of the virtual antennas VX[2,1], VX[2,2], VX[2,3], and VX[2,4].

[0060] In addition, the first spectrum analysis unit 32 performs spectrum analysis processing on the received signals s[3,1], s[3,2], s[3,3], and s[3,4] of the virtual antennas VX[3,1], VX[3,2], VX[3,3], and VX[3,4].

[0061] The analysis processing result z by the first spectrum analysis unit 32 ｈ （ｎｔ） is expressed by the following equation (14): The spectrum analysis process in the first spectrum analysis unit 32 is exemplified by FFT processing, for example.

[0062]

[0063] C shown in the above formula (14) ｈ （ｎｔ） is the analysis processing result z by the first spectrum analysis unit 32 ｈ （ｎｔ） The analysis result z ｈ （ｎｔ） The complex amplitude component C of ｈ （ｎｔ） is shown in the following equation (15).

[0064]

[0065] The angle η between the y-axis and the direction seen from the receiving point R ｒ and the azimuth angle θ as seen from the receiving point R ｒ and elevation angle φ ｒ is expressed by the following relational expression (16).

[0066]

[0067] From the above formulas (14) and (16), the following formula (17) is obtained. Note that "∠" shown in the formula is an operator for calculating an angle from a complex number. Also, "*" is a symbol indicating a wildcard. In the following formula (17), the analysis processing result z by the first spectrum analysis unit 32 shown in the above formula (14) is ｈ （１） , z ｈ （２） , z ｈ （３） It is shown that any of the above is applicable.

[0068]

[0069] The second distance calculation unit 33 calculates the distance r from the receiving point R using the above equations (13) and (17). ｒ Calculate the distance r ｒ Substituting this into the above equation (11), the distance r seen from the transmitting point T is ｔ (second distance estimation processing step S300). In the present disclosure, the distance calculation operation in the second distance calculation unit 33 is also referred to as a "bistatic or multistatic operation."

[0070] The angle η between the y-axis and the direction seen from the transmitting point T ｔ and the azimuth angle θ as seen from the transmitting point T ｔ and elevation angle φ ｔ is expressed by the following relational expression (18).

[0071]

[0072] The angle η between the y-axis and the direction seen from the transmitting point T ｔ Using the above formula, the following formula (19) is obtained by the law of cosines, and by modifying formula (19), the following formula (20) is obtained.

[0073]

[0074]

[0075] The distance r from the receiving point R calculated by the second distance calculation unit 33 ｒ , and the distance r seen from the transmitting point T ｔ By substituting into the above equation (20), cosη ｔ is obtained.

[0076] The phase corrector 34 calculates the analysis result z ｈ （ｎｔ） The complex amplitude component C of ｈ （ｎｔ） The phase-corrected complex amplitude component C ｈｃ （ｎｔ） is generated (phase correction processing step S400).

[0077]

[0078] The second spectrum analyzer 35 calculates the corrected complex amplitude component C obtained by the above equation (21). ｈｃ （１） , C ｈｃ （２） , C ｈｃ （３） Then, the spectrum analysis process is performed (second spectrum analysis process step S500).

[0079] The analysis processing result z by the second spectrum analysis unit 35 ｖ is expressed by the following equation (22): The spectrum analysis process in the second spectrum analysis unit 35 is exemplified by FFT processing, for example.

[0080]

[0081] Elevation and depression angle φ as seen from transmitting point T ｔ can be expressed by the following equation (23): ｔ can be expressed by the following equation (24).

[0082]

[0083]

[0084] The angle calculation unit 36 ​​calculates the analysis processing result z ｖ Applying this to the above equation (23), the elevation / depression angle φ as seen from the transmitting point T is obtained. ｔ Calculate the elevation / depression angle φ ｔ and the analysis processing result z by the first spectrum analysis unit 32 ｈ （＊） Applying this to the above equation (24), the azimuth angle θ as seen from the transmitting point T is ｔ is calculated (angle calculation processing step S600).

[0085] Then, the processing unit 30 calculates the distance r from the transmission point T calculated by the second distance calculation unit 33. ｔ , the elevation / depression angle φ as seen from the transmission point T calculated by the angle calculation unit 36 ｔ , and the azimuth angle θ as seen from the transmitting point T ｔ Polar coordinates with elements {r ｔ , θ ｔ , φ ｔ} is converted into polar coordinates with the origin of the three-dimensional space as the reference point. ｔ , θ ｔ , φ ｔ} is translated in the y direction by a distance -d, ｔ ', θ ｔ ', φ ｔ '} is generated (polar coordinate generation processing step S700).

[0086] The position estimation system 1 and the position estimation process according to the above-described embodiment can improve the accuracy of position estimation using the origin of three-dimensional space as a reference point. Specifically, for example, distance estimation is performed as a monostatic system, and accuracy that is approximately 20 times higher can be achieved compared to conventional technology that estimates the position of a target in a two-dimensional plane including the transmitter, receiver, and target using the angle measured by the receiver and the known distance between the transmitter and receiver.

[0087] (Modification) Fig. 7 is a block diagram showing a schematic configuration of a position estimation system according to a modification. In the following description, descriptions that are the same as those in the embodiment may be omitted.

[0088] The position estimation system 1a according to the modified example includes a transmitter 10a, a receiver 20, and a processor 30a. The processor 30a includes a first distance estimation unit 31, a first spectrum analysis unit 32a, a second distance calculation unit 33, a second spectrum analysis unit 35a, and an angle calculation unit 36.

[0089] The position estimation system 1a according to the modification differs from the position estimation system 1 according to the embodiment in that the transmitting antennas TX[n ｔ ] are arranged in different directions. Fig. 8A is a conceptual diagram showing an example of the arrangement of transmitting antennas in a position estimation system according to a modified example. Fig. 8B is a conceptual diagram showing an example of the arrangement of receiving antennas in a position estimation system according to a modified example. Fig. 8C is a conceptual diagram showing a virtual antenna formed by the transmitting antennas and receiving antennas in a position estimation system according to a modified example.

[0090] Specifically, in the example shown in FIG. 8A, the transmitting antenna TX[n ｔ] are arranged side by side in the z direction (first direction) on the yz plane. More specifically, the transmitting antennas TX[n ｔ ] is the distance d in the z direction Ａ They are arranged in a staggered manner.

[0091] In the example shown in FIG. 8B, the receiving antenna RX[n ｒ ] are arranged side by side in the y direction (second direction) on the yz plane. More specifically, the receiving antennas RX[n ｒ ] is the distance d in the y direction Ａ They are arranged in a staggered manner.

[0092] In other words, multiple transmit antennas TX[n ｔ ] and the arrangement direction of the multiple receiving antennas RX[n ｒ ] are arranged orthogonal to each other. ｔ ] and multiple receiving antennas RX[n ｒ ] and a plurality of virtual antennas VX[n ｔ , n ｒ ] is configured in a rectangular shape on the yz plane as shown in FIG. 8C.

[0093] Note that the transmitting antenna TX[n ｔ ] and the arrangement of the receiving antennas RX[n ｒ The arrangement of two adjacent transmitting antennas TX[n ｔ ] and the direction in which two adjacent receiving antennas RX[n ｒ ] may be orthogonal to each other on the yz plane orthogonal to the x direction.

[0094] FIG. 9 is a flowchart showing an example of a position estimation method according to a modified example.

[0095] In the position estimation system 1a according to the modified example, the analysis processing result z ｈ （ｎｔ） The complex amplitude component C of ｈ （ｎｔ）is expressed by the following equation (25). As a result, the complex amplitude component C ｈ （ｎｔ） This eliminates the need for phase correction processing.

[0096]

[0097] The second spectrum analyzer 35a calculates the complex amplitude component C ｈ （１） , C ｈ （２） , C ｈ （３） Then, the second spectral analysis process is executed (second spectral analysis process step S500a).

[0098] The position estimation system 1a and the position estimation process according to the modification of the embodiment described above make it possible to omit the phase correction process (phase correction process step S400) by the phase corrector 34 described in the embodiment.

[0099] The spectral analysis processing in the first distance estimation unit 31, the first spectral analysis unit 32 (32a), and the second spectral analysis unit 35 (35a) is not limited to FFT processing, and may be processing using a high-resolution spectral estimation algorithm such as the AF (Annihilating Filter) method (hereinafter also referred to as the "AF method"). Specifically, for example, by applying the AF method to the first spectral analysis processing, the analysis processing result z by the first spectral analysis unit 32 (32a) can be ｈ （ｎｔ） This can improve the resolution, and in turn improve the accuracy of the distance calculation result by the second distance calculation unit 33 and the angle calculation result by the angle calculation unit 36.

[0100] The above-described embodiments are intended to facilitate understanding of the present disclosure and are not intended to limit the present disclosure. The present disclosure may be modified or improved without departing from the spirit thereof, and equivalents thereof are also included in the present disclosure.

[0101] For example, in the above-described embodiment, the receiving antennas are arranged side by side in one direction (first direction) on the yz plane, and the transmitting antennas are arranged shifted in the y and z directions, but the transmitting antennas may be arranged side by side in one direction (first direction) on the yz plane, and the receiving antennas may be arranged shifted in the y and z directions. In this case, the processing flow for spectrum estimation is the same as that shown in, for example, Figures 5 and 9, but the spectrum analysis direction and various calculation formulas are changed as appropriate depending on the antenna arrangement.

[0102] For example, one of the receiving antennas or the transmitting antennas may be arranged side by side in one direction (first direction) on the yz plane, and the other may be arranged offset in the y and z directions, so that the virtual antenna is configured in the shape of a combination of multiple parallelograms on the yz plane.

[0103] Alternatively, the shape of the virtual antenna may be, for example, a dogleg shape as shown in FIG. 10A or a zigzag shape as shown in FIG. 11A.

[0104] 10A is a conceptual diagram showing a first modified example of a virtual antenna, FIG. 10B is a conceptual diagram showing an example of the arrangement of transmitting antennas that constitute the virtual antenna according to the first modified example, and FIG. 10C is a conceptual diagram showing an example of the arrangement of receiving antennas that constitute the virtual antenna according to the first modified example.

[0105] 11A is a conceptual diagram showing a second modified example of a virtual antenna, FIG. 11B is a conceptual diagram showing an example of the arrangement of transmitting antennas that constitute a virtual antenna according to the second modified example, and FIG. 11C is a conceptual diagram showing an example of the arrangement of receiving antennas that constitute a virtual antenna according to the second modified example.

[0106] Specifically, for example, as shown in FIG. 10C, receiving antennas RX[1], RX[2], RX[3], and RX[4] are arranged side by side in the y direction on the yz plane, and as shown in FIG. 10B, transmitting antenna TX[2] is positioned at a distance d Ａ By displacing the antennas by only 1 / 2, the virtual antenna can be shaped like a dogleg as shown in FIG. 10A.

[0107] 11C, the receiving antennas RX[1], RX[2], RX[3], and RX[4] are arranged side by side in the y direction on the yz plane, and as shown in FIG. 11B, the direction in which the transmitting antennas TX[2] and TX[4] are arranged is separated from the direction in which the transmitting antennas TX[1] and TX[3] are arranged by a distance d Ａ By displacing the antennas by only a certain distance, the virtual antenna can be shaped in a zigzag pattern as shown in FIG. 11A.

[0108] The present disclosure can have the following configurations as described above or instead of the above.

[0109] (1) A bistatic or multistatic position estimation system in which one or more transmitters and one or more receivers are arranged separately from each other, comprising: a transmitter having a plurality of transmitter antennas; a receiver having a plurality of receiver antennas; and a processing unit that estimates the position of a target in three-dimensional space based on received signals acquired by a plurality of virtual antennas formed by combining a plurality of the transmitter antennas and a plurality of the receiver antennas, wherein the arrangement direction of two adjacently arranged transmitter antennas and the arrangement direction of two adjacently arranged receiver antennas are different from each other on a yz plane orthogonal to the x direction, and the processing unit includes: a first distance estimation unit that estimates distance based on monostatic operation; a first spectrum analysis unit that performs spectrum analysis of received signals from virtual antennas arranged in the y direction; a second distance calculation unit that calculates distance based on bistatic or multistatic operation based on the analysis result by the first spectrum analysis unit; a phase correction unit that performs phase correction on complex amplitude components of the analysis result by the first spectrum analysis unit; and a second spectrum analysis unit that performs spectrum analysis of the correction result by the phase correction unit. an angle calculation unit that calculates an azimuth angle and an elevation / depression angle based on analysis results by the first spectrum analysis unit and the second spectrum analysis unit.(2) A bistatic or multistatic position estimation system in which one or more transmitters and one or more receivers are arranged separately from each other, comprising: a transmitter having a plurality of transmitter antennas; a receiver having a plurality of receiver antennas; and a processing unit that estimates the position of a target in three-dimensional space based on received signals acquired by a plurality of virtual antennas formed by combining a plurality of the transmitter antennas and a plurality of the receiver antennas, wherein the arrangement direction of two adjacently arranged transmitter antennas and the arrangement direction of two adjacently arranged receiver antennas are orthogonal to each other on a yz plane that is orthogonal to the x direction, and the processing unit comprises: a first distance estimation unit that estimates distance based on monostatic operation; a first spectral analysis unit that performs spectral analysis of received signals from virtual antennas arranged in the y direction; a second distance calculation unit that calculates distance based on bistatic or multistatic operation based on the analysis result by the first spectral analysis unit; and a second spectral analysis unit that performs spectral analysis of complex amplitude components of the analysis result by the first spectral analysis unit. and an angle calculation unit that calculates an azimuth angle and an elevation / depression angle based on analysis results by the first spectrum analysis unit and the second spectrum analysis unit. (3) The position estimation system according to (1) or (2), wherein the first spectrum analysis unit performs spectrum analysis using an annihilating filter (AF) method. (4) The position estimation system according to any one of (1) to (3), wherein the second spectrum analysis unit performs spectrum analysis using an annihilating filter (AF) method.(5) A position estimation method for estimating a position of a target in three-dimensional space based on received signals acquired by a plurality of virtual antennas formed by a combination of a plurality of transmitting antennas and a plurality of receiving antennas in a bistatic system or multistatic system in which one or more transmitting units and one or more receiving units are respectively arranged at a distance from each other, wherein the arrangement direction of two adjacently arranged transmitting antennas and the arrangement direction of two adjacently arranged receiving antennas are different from each other on a yz plane orthogonal to the x direction, and the method includes: a first distance estimation step of estimating a distance based on monostatic operation; a first spectral analysis step of performing a spectral analysis of the received signals of the virtual antennas arranged in the y direction; a second distance calculation step of calculating a distance based on a bistatic or multistatic operation based on an analysis result in the first spectral analysis step; a phase correction step of performing a phase correction on a complex amplitude component of the analysis result in the first spectral analysis step; a second spectral analysis step of performing a spectral analysis of the correction result in the phase correction step; and an angle calculation step of calculating an azimuth angle and an elevation / depression angle based on the analysis results in the first spectral analysis step and the second spectral analysis step. Location estimation method.(6) A position estimation method for estimating a position of a target in three-dimensional space based on received signals acquired by a plurality of virtual antennas formed by a combination of a plurality of transmitting antennas and a plurality of receiving antennas in a bistatic system or a multistatic system in which one or more transmitting units and one or more receiving units are respectively arranged at a distance from each other, the position estimation method comprising: a first distance estimation step of estimating a distance based on monostatic operation; a first spectral analysis step of performing a spectral analysis of received signals of the virtual antennas arranged in the y direction; a second distance calculation step of calculating a distance based on bistatic or multistatic operation based on an analysis result in the first spectral analysis step; a second spectral analysis step of performing a spectral analysis of complex amplitude components of the analysis result in the first spectral analysis step; and an angle calculation step of calculating an azimuth angle and an elevation / depression angle based on the analysis results in the first spectral analysis step and the second spectral analysis step. (7) The position estimation method according to (5) or (6), wherein in the first spectrum analysis step, spectrum analysis is performed using an AF (Annihilating Filter) method. (8) The position estimation method according to any one of (5) to (7), wherein in the second spectrum analysis step, spectrum analysis is performed using an AF (Annihilating Filter) method.

[0110] The present disclosure enables target position estimation in three-dimensional space in a bistatic or multistatic system.

[0111] 1, 1a Position estimation system 10, 10a Transmitter 20 Receiver 30, 30a Processing unit 31 First distance estimation unit 32, 32a First spectrum analyzer 33 Second distance calculation unit 34 Phase correction unit 35, 35a Second spectrum analyzer 36 Angle calculation unit

Claims

1. A bistatic or multistatic position estimation system in which one or more transmitters and one or more receivers are arranged separately from each other, comprising: a transmitter having a plurality of transmit antennas; a receiver having a plurality of receive antennas; and a processing unit that estimates the position of a target in three-dimensional space based on received signals acquired by a plurality of virtual antennas formed by combining a plurality of the transmitter antennas and a plurality of the receive antennas, wherein the arrangement direction of two adjacently arranged transmitter antennas and the arrangement direction of two adjacently arranged receive antennas are different from each other on a yz plane orthogonal to the x direction, and the processing unit comprises: a first distance estimation unit that estimates distance based on monostatic operation; a first spectrum analysis unit that performs spectrum analysis of received signals from the virtual antennas arranged in the y direction; a second distance calculation unit that calculates distance based on bistatic or multistatic operation based on the analysis result by the first spectrum analysis unit; a phase correction unit that performs phase correction on complex amplitude components of the analysis result by the first spectrum analysis unit; and a second spectrum analysis unit that performs spectrum analysis of the correction result by the phase correction unit. an angle calculation unit that calculates an azimuth angle and an elevation / depression angle based on analysis results by the first spectrum analysis unit and the second spectrum analysis unit.

2. A bistatic or multistatic position estimation system in which one or more transmitters and one or more receivers are arranged separately from each other, comprising: a transmitter having a plurality of transmitter antennas; a receiver having a plurality of receiver antennas; and a processing unit that estimates the position of a target in three-dimensional space based on received signals acquired by a plurality of virtual antennas formed by combining a plurality of the transmitter antennas and a plurality of the receiver antennas, wherein the arrangement direction of two adjacently arranged transmitter antennas and the arrangement direction of two adjacently arranged receiver antennas are orthogonal to each other on a yz plane that is orthogonal to the x direction, and the processing unit comprises: a first distance estimation unit that estimates distance based on monostatic operation; a first spectral analysis unit that performs spectral analysis of received signals from the virtual antennas arranged in the y direction; a second distance calculation unit that calculates distance based on bistatic or multistatic operation based on the analysis result by the first spectral analysis unit; and a second spectral analysis unit that performs spectral analysis of complex amplitude components of the analysis result by the first spectral analysis unit. an angle calculation unit that calculates an azimuth angle and an elevation / depression angle based on analysis results by the first spectrum analysis unit and the second spectrum analysis unit.

3. A position estimation system according to claim 1 or 2, wherein the first spectrum analysis unit performs spectrum analysis using an AF (Annihilating Filter) method.

4. A position estimation system according to any one of claims 1 to 3, wherein the second spectrum analysis unit performs spectrum analysis using an AF (Annihilating Filter) method.

5. A position estimation method for estimating the position of a target in three-dimensional space based on received signals acquired by multiple virtual antennas formed by a combination of multiple transmitting antennas and multiple receiving antennas in a bistatic or multistatic system in which one or more transmitting units and one or more receiving units are respectively arranged at a distance from each other, wherein the arrangement direction of two adjacently arranged transmitting antennas and the arrangement direction of two adjacently arranged receiving antennas are different from each other on a yz plane perpendicular to the x direction, the method comprising: a first distance estimation step for estimating distance based on monostatic operation; a first spectral analysis step for performing spectral analysis of received signals from virtual antennas arranged in the y direction; a second distance calculation step for calculating distance based on the analysis result of the first spectral analysis step based on bistatic or multistatic operation; a phase correction step for performing phase correction on complex amplitude components of the analysis result of the first spectral analysis step; a second spectral analysis step for performing spectral analysis of the correction result of the phase correction step; and an angle calculation step for calculating azimuth angle and elevation / depression angle based on the analysis results of the first spectral analysis step and the second spectral analysis step. Location estimation method.

6. A position estimation method for estimating the position of a target in three-dimensional space based on received signals acquired by multiple virtual antennas formed by a combination of multiple transmitting antennas and multiple receiving antennas in a bistatic or multistatic system in which one or more transmitting units and one or more receiving units are respectively arranged at a distance from each other, wherein the arrangement direction of two adjacently arranged transmitting antennas and the arrangement direction of two adjacently arranged receiving antennas are orthogonal to each other on a yz plane orthogonal to the x direction, and the position estimation method comprises: a first distance estimation step for estimating distance based on monostatic operation; a first spectral analysis step for performing spectral analysis of received signals from virtual antennas arranged in the y direction; a second distance calculation step for calculating distance based on bistatic or multistatic operation based on the analysis result of the first spectral analysis step; a second spectral analysis step for performing spectral analysis of complex amplitude components of the analysis result of the first spectral analysis step; and an angle calculation step for calculating azimuth angle and elevation / depression angle based on the analysis results of the first spectral analysis step and the second spectral analysis step.

7. A location estimation method according to claim 5 or 6, wherein in the first spectrum analysis step, spectrum analysis is performed using an AF (Annihilating Filter) method.

8. A location estimation method according to any one of claims 5 to 7, wherein in the second spectrum analysis step, spectrum analysis is performed using an AF (Annihilating Filter) method.

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