Receiving device, radar device, vehicle and communication system equipped with the receiving device

Abstract

The present invention provides a receiving device that can use the AF method to perform angle estimation of an arrival wave in a two-dimensional direction with high accuracy, and a radar device, a vehicle, and a communication system equipped with the receiving device. The receiving device is configured to include a first linear array antenna, a second linear array antenna, and a computing device. The first linear array antenna arranges four first receiving antennas, which are two more than the number of arrival waves, at equal intervals (L) on a straight line, and the second linear array antenna arranges four second receiving antennas at intervals (L) on a straight line parallel to the straight line in which the first linear array antennas are arranged at a height different from that of the first linear array antenna. The computing device includes an azimuth phase difference first estimation unit, an azimuth phase difference second estimation unit, an arrival wave signal first estimation unit, an arrival wave signal second estimation unit, an elevation phase difference estimation unit, and an arrival direction two-dimensional estimation unit.

Description

Technical Field

[0001] The present invention relates to a receiving device for estimating the angle of arrival direction of an arrival wave, and a radar device, a vehicle, and a communication system equipped with the receiving device. Background Art

[0002] Conventionally, as a technique for estimating the angle of the arrival direction of an arriving wave, there is an angle estimation technique using an AF (Annihilating Filter) method in a MIMO (Multiple-Input Multiple-Output) radar device disclosed in Non-Patent Document 1, for example.

[0003] The MIMO radar device described in Non-Patent Document 1 has an equally spaced linear array formed by arranging receiving antennas at equal intervals. In the MIMO radar device, a filter having a transfer function H(z) is required that takes the received signals x(n), x(n+1), x(n+2), ... received by each receiving antenna as input and sets the output y to 0. In addition, the phase of the zero point of the filter is observed to grasp the phase difference of the arriving wave between the receiving antennas, and the angle of the direction of arrival of the arriving wave is estimated with high accuracy based on the grasped phase difference.

[0004] Non-patent literature 1: Tianyun Wang, Bing Liu, Qiang Wei, Kai Kang, Yong Liu, "Frequency Diverse MIMO Radar Sparse Imaging Using Annihilating Filter", ChinaSatellite Maritime Tracking and Control Department, Jiangyin, 214431, PRChina, 978-1-5386-7946-3 / 18 / $31.00 2018 IEEE

[0005] However, in the above-mentioned conventional angle estimation technology using the AF method, only the azimuth angle can be estimated, and only one-dimensional angle estimation can be performed. Summary of the invention

[0006] An object of the present invention is to provide a receiving technology that can use the AF method to perform two-dimensional angle estimation with high accuracy, which can estimate not only the azimuth angle of the direction in which an arriving wave arrives, but also the elevation angle.

[0007] To this end, the present invention is a receiving device having the following components:

[0008] A first linear array antenna, comprising a plurality of first receiving antennas, the number of which is at least one more than the number of arrival waves, arranged on a straight line at equal intervals, each of the first receiving antennas receiving a first reception signal having a phase that is different from the phase of each arrival wave received by a reference first receiving antenna that is one of the plurality of first receiving antennas by a phase difference corresponding to the interval according to each arrival wave, and having an amplitude corresponding to each arrival wave;

[0009] a second linear array antenna, wherein a plurality of second receiving antennas, which are at least one more than the number of arrival waves, are arranged on a straight line parallel to the straight line at intervals equal to the intervals at a height different from that of the first linear array antenna, wherein each second receiving antenna receives a second received signal having a phase that is different from the phase of each arrival wave including a phase difference corresponding to the height received by a reference second receiving antenna that is one of the plurality of second receiving antennas, and having an amplitude corresponding to each arrival wave;

[0010] an azimuth phase difference first estimation unit that estimates the azimuth phase difference of each arrival wave between each first receiving antenna by an AF method based on the phase at the zero point of a transfer function that divides a first reception signal group consisting of first reception signals into a plurality of groups and inputs the first reception signals so that each output for each input first reception signal group is 0, wherein the first reception signals are signals received by the first reception antenna and the number of the signals is one more than the number of arrival waves;

[0011] a second azimuth phase difference estimation unit that estimates the azimuth phase difference of each arrival wave between each second receiving antenna by an AF method based on the phase at the zero point of a transfer function that divides a second reception signal group consisting of second reception signals into a plurality of groups and inputs the second reception signals so that each output for each input second reception signal group is 0, wherein the second reception signals are signals received by the second reception antenna and the number of the second reception signals is one more than the number of arrival waves;

[0012] an arrival wave signal first estimation unit that estimates the amplitude and phase of each arrival wave signal that has arrived at the reference first receiving antenna based on the azimuth phase difference of each arrival wave between the first receiving antennas estimated by the azimuth phase difference first estimation unit and the first received signal;

[0013] The second arrival wave signal estimation unit estimates the amplitude and phase of each arrival wave signal reaching the reference second receiving antenna based on the azimuth phase difference of each arrival wave between each second receiving antenna estimated by the second azimuth phase difference estimation unit and the second received signal;

[0014] an elevation phase difference estimation unit that estimates a phase difference corresponding to the height for each arrival wave as an elevation phase difference, based on the signal of each arrival wave estimated by the arrival wave signal first estimation unit as arriving at the reference first receiving antenna and the signal of each arrival wave estimated by the arrival wave signal second estimation unit as arriving at the reference second receiving antenna; and

[0015] The two-dimensional arrival direction inference unit infers the elevation angle of the arrival direction of each arrival wave based on the elevation phase difference inferred by the elevation phase difference inference unit, and infers the azimuth angle of the arrival direction of each arrival wave based on the azimuth phase difference inferred by the first azimuth phase difference inference unit or the second azimuth phase difference inference unit.

[0016] In addition, the present invention constitutes a radar device, comprising: a transmission signal generator that generates a transmission signal; a transmission antenna that transmits the transmission signal generated by the transmission signal generator as a transmission wave; an angle estimation unit that estimates the angle of the position of a target object in a two-dimensional direction based on the elevation angle and azimuth angle of the arrival direction of the arrival wave estimated by the above-mentioned receiving device; and a distance estimation unit that estimates the distance to the target object.

[0017] Furthermore, the present invention constitutes a vehicle including the above-mentioned radar device.

[0018] In addition, the present invention constitutes a communication system, wherein a base station or a mobile device is provided with: an angle estimation unit for estimating the angle of a position of a mobile device or a base station that sends an arrival wave in a two-dimensional direction, based on the elevation angle and the azimuth angle of the arrival direction of the arrival wave estimated by the above-mentioned receiving device; and a transmitting unit for improving the directionality control of the transmission output of the transmission wave sent in the direction of the mobile device or the base station by performing beamforming toward the angle estimated by the angle estimation unit.

[0019] In addition, the present invention constitutes a communication system, which includes in a mobile device or a base station: an angle estimation unit, which estimates the angle of the position of the base station or mobile device that sends the arrival wave in a two-dimensional direction based on the elevation angle and azimuth angle of the arrival direction of the arrival wave estimated by the above-mentioned receiving device; and a receiving unit, which performs directivity control to improve the receiving sensitivity of the receiving wave received from the direction of the base station or mobile device by performing beamforming toward the angle estimated by the angle estimation unit.

[0020] In addition, the present invention provides a position detection system, comprising: a plurality of transmitters, which are installed on each target and output transmission waves; and an angle inference unit, which performs angle inference of the position of each target in a two-dimensional direction based on the elevation angle and azimuth angle of the arrival direction of each arrival wave inferred by the above-mentioned receiving device, wherein the above-mentioned receiving device receives each transmission wave output from each transmitter as each arrival wave.

[0021] According to the present invention, it is possible to provide a receiving device that can use the AF method to accurately estimate the angle of an arrival wave in a two-dimensional direction, and a radar device, a vehicle, and a communication system including the receiving device. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a block diagram showing a schematic structure of a receiving device according to one embodiment of the present invention.

[0023] Figure 2 This is a diagram for explaining a transfer function in a receiving device according to an embodiment.

[0024] Figure 3 This is a flowchart showing the operation of a computing device in a receiving device according to one embodiment.

[0025] Figure 4 This is a block diagram showing a schematic configuration of a radar device according to one embodiment of the present invention.

[0026] Figure 5 Yes means Figure 4 A block diagram showing a schematic configuration of a modified example of the radar device shown.

[0027] Figure 6 Yes means have Figure 3 , Figure 4 A diagram showing a schematic structure of a radar device for a vehicle is shown.

[0028] Figure 7 It is a diagram showing a schematic configuration of a communication system according to one embodiment of the present invention.

[0029] Figure 8 It is a diagram showing a schematic configuration of a position detection system according to one embodiment of the present invention. DETAILED DESCRIPTION

[0030] Next, the receiving device and the radar device, vehicle, and communication system provided with the receiving device according to the present invention will be described. In the following description, m, n, and k represent natural numbers.

[0031] Figure 1 It is a block diagram showing a schematic structure of a receiving device 1 according to one embodiment of the present invention.

[0032] The receiving device 1 includes a first linear array antenna 2 , a second linear array antenna 3 , and a computing device 4 .

[0033] The first linear array antenna 2 is provided by providing a plurality of first receiving antennas 20, 21, 22, ... 2 which are at least one more than the number of arrival waves. nThe first linear array antenna 2 is configured by arranging the first receiving antennas 20, 21, 22, and 23 at equal intervals L on a straight line. In the present embodiment, the two waves of the arrival wave P shown by the solid line and the arrival wave Q shown by the dotted line in the figure arrive at the receiving device 1, and the first linear array antenna 2 is configured by arranging the four first receiving antennas 20, 21, 22, and 23, which are two more than the number of the arrival waves P and Q, at equal intervals L on a straight line. The first receiving signals x(0), x(1), x(2), and x(3) shown in the following formula (1) are received by each of the first receiving antennas 20, 21, 22, and 23, respectively.

[0034] [Formula 1]

[0035]

[0036]

[0037]

[0038]

[0039] Each first received signal x(0), x(1), x(2), x(3) has a phase α1, α2 of each arrival wave P, Q received by a reference first receiving antenna 20, which is one of the four first receiving antennas 20, 21, 22, 23, as a reference, and has a phase difference (azimuth phase difference) u1, u2 corresponding to the interval L for each antenna in each of the first receiving antennas 20, 21, 22, 23 according to each arrival wave P, Q, and has an amplitude A1, A2 corresponding to each arrival wave P, Q.

[0040] The second linear array antenna 3 is formed by arranging a plurality of second receiving antennas 30, 31, 32, 33, which are at least one more than the number of arrival waves, at an interval L equal to the interval L between the first linear array antennas 2, on a straight line parallel to the straight line on which the first linear array antennas 2 are arranged, at a height different from the first linear array antenna 2. In the present embodiment, four second receiving antennas 30, 31, 32, 33, which are two more than the number of arrival waves P and Q, are arranged at an equal interval L at a height T relative to the first linear array antenna 2 on a straight line parallel to the straight line on which the first linear array antennas 2 are arranged. Each of the second receiving antennas 30, 31, 32, 33 receives the second received signals x(4), x(5), x(6), x(7) represented by the following equation (2), respectively.

[0041] [Formula 2]

[0042]

[0043]

[0044]

[0045]

[0046] Each second received signal x(4), x(5), x(6), x(7) has a phase α1+u1+v1, α2+u2+v2 of each arrival wave P, Q including a phase difference (elevation phase difference) v1, v2 corresponding to the height T received by a reference second receiving antenna 30 which is one of the four second receiving antennas 30, 31, 32, 33 as a reference, and has a phase difference (azimuth phase difference) u1, u2 corresponding to the interval L for each antenna in each second receiving antenna 30, 31, 32, 33 according to each arrival wave P, Q, and has an amplitude A1, A2 corresponding to each arrival wave P, Q.

[0047] The computing device 4 includes a processor, which is composed of an MPU (Micro Processing Unit) and the like, and controls each part according to a program storing in a storage unit that specifies the operation steps of the processor. The computing device 4 includes an azimuth phase difference first estimation unit 4a, an azimuth phase difference second estimation unit 4b, an arrival wave signal first estimation unit 4c, an arrival wave signal second estimation unit 4d, an elevation phase difference estimation unit 4e, and an arrival direction two-dimensional estimation unit 4f as its functional modules.

[0048] The azimuth phase difference first estimation unit 4a divides the first reception signal group consisting of the first reception signals received by the first reception antennas 20, 21, 22, and 23, which are one more than the number of arrival waves, into a plurality of groups and inputs them. In the present embodiment, the first reception signal group consisting of three first reception signals, which are one more than the number of arrival waves P and Q, i.e., two, is divided into two groups, a first first reception signal group of x(2), x(1), and x(0) and a second first reception signal group of x(3), x(2), and x(1), and inputs them. Then, the azimuth phase differences u1 and u2 of the arrival waves P and Q between the first reception antennas 20, 21, 22, and 23 are estimated by the AF method based on the phase at the zero point of the transfer function H(z) that makes each output for each input first reception signal group zero.

[0049] like Figure 2 As shown in FIG. 1 , in the AF method, the filter is designed so that the received signals x(n), x(n+1), x(n+2) ... input to the filter 5 are divided by the arrival wave number K+1, and the transfer function H(z) of the filter 5 makes the filter output y equal to 0 for each input. If the phase difference between antennas is z, and the filter coefficients are h0, h1, ... h K-1 、h K , then the transfer function H(z) is generally expressed by the following formula (12).

[0050] [Formula 12]

[0051] H(z)=h0z K +h1z K-1 +…+h K-1 z+h K …(12)

[0052] In the present embodiment, since the arrival wave number K+1=3, the transfer function H(z) is expressed by the following equation (4).

[0053] [Formula 4]

[0054] H(z)=h0z 2 +h1z+h2…(4)

[0055] Here, since the filter output obtained based on the above two first received signal groups x(2), x(1), x(0) and x(3), x(2), x(1) input to the filter 5, and the transfer function H(z) is 0, the following equations (3-1) and (3-2) hold true.

[0056] [Formula 3]

[0057]

[0058] The above formula (3-1) is transformed into the following formula (13).

[0059] [Formula 13]

[0060]

[0061] In addition, equation (3-2) is transformed into the following equation (14).

[0062] [Formula 14]

[0063]

[0064] In order to make the above-mentioned formula (13) and formula (14) equal to 0 at the same time, the common part a of formula (13) and formula (14) shown by the solid underline and the common part b of formula (13) and formula (14) shown by the dotted underline in each formula need to be 0. Here, the term having the common part a corresponds to the arrival wave P, and the term having the common part b corresponds to the arrival wave Q. Therefore, the values ​​of the three filter coefficients h0, h1, and h3 are changed, and the values ​​of the filter coefficients h0, h1, and h3 that make the values ​​of the common parts a and b converge to 0 are calculated.

[0065] If the values ​​of the filter coefficients h0, h1, and h3 are determined, the first azimuth phase difference inference unit 4a calculates the phase difference z1 with respect to the arrival wave P and the phase difference z2 with respect to the arrival wave Q between the first receiving antennas 20, 21, 22, and 23 when the transfer function H(z) represented by equation (4) is 0, that is, calculates the phase differences z1 and z2 that satisfy the following equation (15), and calculates the zero point of the filter 5.

[0066] [Formula 15]

[0067] h0z1 2 +h1z1+h2=0

[0068] h0z2 z +h1z2+h2=0(15)

[0069] The left sides of the above-mentioned formula (15) are in the same formula shape as the common part a and the common part b of formula (13) and formula (14). Since the filter coefficients h0, h1, and h3 should be values ​​that make the common parts a and b both 0, the zero points of filter 5 are the two represented by the following formula (5).

[0070] [Formula 5]

[0071]

[0072]

[0073] The azimuth phase difference first estimation unit 4a estimates the azimuth phase differences u1 and u2 of the arrival waves P and Q between the first receiving antennas 20, 21, 22, and 23 by the AF method based on the phase at the zero point.

[0074] Similarly, the azimuth phase difference second estimation unit 4b divides the second reception signal group consisting of three second reception signals, one more than the number of arrival waves P, Q, received by the second reception antennas 30, 31, 32, 33 into two groups, namely, a first second reception signal group of x(6), x(5), x(4) and a second second reception signal group of x(7), x(6), x(5), and inputs them. Then, the azimuth phase differences u1, u2 of the arrival waves P, Q between the second reception antennas 30, 31, 32, 33 are estimated by the AF method based on the phase at the zero point of the transfer function H(z) that makes each output for each input second reception signal group zero.

[0075] That is, since the filter output obtained based on the above two second received signal groups x(6), x(5), x(4) and x(7), x(6), x(5) input to the filter 5, and the transfer function H(z) is 0, the following equations (6-1) and (6-2) hold true.

[0076] [Formula 6]

[0077]

[0078] Formula (6-1) and Formula (6-2) are transformed in the same way as Formula (13) and Formula (14), and the second azimuth phase difference estimation unit 4b calculates the values ​​of the filter coefficients h0, h1, and h3 that converge the values ​​of the common parts a and b to 0. When the values ​​of the filter coefficients h0, h1, and h3 are determined, the second azimuth phase difference estimation unit 4b obtains the phase difference z1 with respect to the arrival wave P and the phase difference z2 with respect to the arrival wave Q between the second receiving antennas 30, 31, 32, and 33 for which the transfer function H(z) represented by Formula (4) is 0, that is, obtains the phase differences z1 and z2 that satisfy Formula (15), and obtains the zero point of the filter 5. Then, similarly to the first azimuth phase difference estimation unit 4a, the azimuth phase differences u1 and u2 of the arrival waves P and Q between the second receiving antennas 30, 31, 32, and 33 are estimated by the AF method based on the phase at the obtained zero point according to Formula (5).

[0079] The first arrival wave signal estimation unit 4c estimates the amplitudes A1, A2 and phases α1, α2 of the signals S1, S2 of each arrival wave arriving at the reference first receiving antenna 20 according to the known azimuth phase differences u1, u2 of each arrival wave P, Q between each first receiving antenna 20, 21, 22, 23 estimated by the first azimuth phase difference estimation unit 4a and the known first received signals x(0), x(1), x(2), x(3) by the following formula (7).

[0080] [Formula 7]

[0081]

[0082]

[0083]

[0084]

[0085] In addition, the second arrival wave signal estimation unit 4d estimates the amplitudes A1, A2 and phases α1+u1+v1, α2+u2+v2 of the arrival wave signals S1′, S2′ arriving at the reference second receiving antenna 30 according to the known azimuth phase differences u1, u2 of the arrival waves P, Q between the second receiving antennas 30, 31, 32, 33 estimated by the second azimuth phase difference estimation unit 4b and the known second received signals x(4), x(5), x(6), x(7) according to the following formula (8).

[0086] [Formula 8]

[0087]

[0088]

[0089]

[0090]

[0091] The elevation phase difference estimation unit 4e estimates the phase difference corresponding to the height T for each arrival wave P, Q as the elevation phase difference v1, v2 based on the amplitude A1, A2 and phase α1, α2 of the signals S1, S2 of each arrival wave estimated by the arrival wave signal first estimation unit 4c as arriving at the reference first receiving antenna 20, and the amplitude A1, A2 and phase α1+u1+v1, α2+u2+v2 of the signals S1′, S2′ of each arrival wave estimated by the arrival wave signal second estimation unit 4d as arriving at the reference second receiving antenna 30, through the following formula (9).

[0092] [Formula 9]

[0093]

[0094]

[0095] The arrival direction two-dimensional estimation unit 4f estimates the elevation angle of the arrival direction of each arrival wave P, Q by the following equation (10) based on the elevation phase differences v1, v2 estimated by the elevation phase difference estimation unit 4e:

[0096] [Formula 10]

[0097]

[0098]

[0099] Then, the arrival direction two-dimensional estimation unit 4f estimates the azimuth angles θ1 and θ2 of the arrival directions of the respective arrival waves P and Q according to the azimuth phase differences u1 and u2 estimated by the azimuth phase difference first estimation unit 4a or the azimuth phase difference second estimation unit 4b by the following formula (11).

[0100] [Formula 11]

[0101]

[0102]

[0103] Figure 3 This is a flowchart showing an overview of the operation of the computing device 4 in the receiving device 1 according to one embodiment.

[0104] When the angle of arrival direction of each arrival wave P, Q is estimated by the AF method, the operation device 4 first divides the first received signals x(0), x(1), x(2), x(3) shown in equation (1) received by the first linear array antenna 2 and the second linear array antenna 3 and the second received signals x(4), x(5), x(6), x(7) shown in equation (2) into three for each antenna in the first linear array antenna 2 and the second linear array antenna 3. Figure 3 , refer to step 101). Then, the divided first reception signal group of x(2), x(1), x(0) and the second first reception signal group of x(3), x(2), x(1) are set as inputs to the filter 5 for the first linear array antenna 2, and the divided first second reception signal group of x(6), x(5), x(4) and the second second reception signal group of x(7), x(6), x(5) are set as inputs to the filter 5 for the second linear array antenna 3.

[0105] Next, the computing device 4 applies the AF method to the first linear array antenna 2 and the second linear array antenna 3 through the first azimuth phase difference estimation unit 4a and the second azimuth phase difference estimation unit 4b, respectively, and calculates the filter coefficients h0, h1, and h3 that make the filter output of the filter 5 having the transfer function H(x) shown in the formula (4) 0 using the formulas (3-1) and (3-2) and the formulas (6-1) and (6-2). Then, the zero point of the filter 5 having the calculated filter coefficients h0, h1, and h3 is obtained as the formula (5), and the azimuth phase differences u1 and u2 between the first receiving antennas 20, 21, 22, and 23 and between the second receiving antennas 30, 31, 32, and 33 are estimated based on the zero point of the filter 5 shown in the formula (5) (refer to step 102).

[0106] Next, the computing device 4 estimates the amplitudes A1, A2 and phases α1, α2 of the signals S1, S2 of the respective arrival waves arriving at the reference first receiving antenna 20 according to equation (7), and estimates the amplitudes A1, A2 and phases α1+u1+v1, α2+u2+v2 of the signals S1′, S2′ of the respective arrival waves arriving at the reference second receiving antenna 30 according to equation (8) (see step 103). Next, the computing device 4 estimates the elevation phase differences v1, v2 of the respective arrival waves P, Q according to equation (9) based on the amplitudes A1, A2 and phases α1, α2 of the signals S1, S2 of the respective arrival waves and the amplitudes A1, A2 and phases α1+u1+v1, α2+u2+v2 of the signals S1′, S2′ of the respective arrival waves according to equation (9) (see step 104), through the elevation phase difference estimation unit 4e. Then, the computing device 4 estimates the elevation angle of the arrival direction of each arrival wave P, Q by using the equation (10) based on the elevation angle phase differences v1, v2 through the arrival direction two-dimensional estimation unit 4f. Then, the azimuth angles θ1 and θ2 of the arrival directions of the arrival waves P and Q are estimated using equation (11) based on the azimuth phase differences u1 and u2 (see step 105).

[0107] According to the receiving device 1 of the present embodiment, by using the azimuth phase difference first inference unit 4a and the azimuth phase difference second inference unit 4b and using the AF method to infer the azimuth phase difference u1, u2 of each arrival wave P, Q for each antenna in the first linear array antenna 2 and the second linear array antenna 3, the azimuth angles θ1, θ2 of the arrival direction of each arrival wave P, Q can be inferred in the arrival direction two-dimensional inference unit 4f based on the azimuth phase difference u1, u2.

[0108] In addition, by configuring and setting the second linear array antenna 3 at a height T different from that of the first linear array antenna 2, the phases of the second received signals x(4), x(5), x(6), and x(7) of the respective arriving waves P and Q received by the second receiving antennas 30, 31, 32, and 33 constituting the second linear array antenna 3 include phase differences (elevation phase differences) v1 and v2 corresponding to the height T. Therefore, based on the azimuth phase differences u1, u2 of the arrival waves P, Q between the first receiving antennas 20, 21, 22, 23 estimated by the first azimuth phase difference estimation unit 4a and the first received signals x(0), x(1), x(2), x(3), it is possible to estimate the amplitudes A1, A2 and phases α1, α2 of the signals S1, S2 of the arrival waves arriving at the reference first receiving antenna 20 by the arrival wave signal first estimation unit 4c, and based on the azimuth phase differences u1, u2 of the arrival waves P, Q between the second receiving antennas 30, 31, 32, 33 estimated by the second azimuth phase difference estimation unit 4b and the second received signals x(4), x(5), x(6), x(7), the amplitude A1, A2 and phase α1+u1+v1, α2+u2+v2 of each arrival wave signal S1′, S2′ arriving at the reference second receiving antenna 30 are estimated by the arrival wave signal second estimation unit 4d, and the phase difference corresponding to the height T of the second linear array antenna 3 is estimated as the elevation phase difference v1, v2 for each arrival wave P, Q by the elevation phase difference estimation unit 4e based on the estimated amplitude A1, A2 and phase α1, α2 of each arrival wave signal S1, S2 and the amplitude A1, A2 and phase α1+u1+v1, α2+u2+v2 of each arrival wave signal S1′, S2′. The elevation angle of the arrival direction of each arrival wave P, Q can be estimated by the arrival wave signal second estimation unit 4d based on the elevation phase differences v1, v2 estimated in this way.

[0109] As a result, the azimuth angles θ1, θ2 and the elevation angles of the arrival directions of the arrival waves P and Q are estimated. The AF method is also used to perform two-dimensional angle estimation of the arrival waves P and Q, which was previously impossible using AF. This can be done with higher accuracy than methods such as high-speed Fourier transform (FFT) and compressed sensing detection.

[0110] In the above embodiment, the case where the reference first receiving antenna is set to the first receiving antenna 20 and the reference second receiving antenna is set to the second receiving antenna 30 is described, but any antenna can be selected as the reference first receiving antenna 20, 21, 22, 23 and the second receiving antenna 30, 31, 32, 33. In the above embodiment, the first linear array antenna 2 and the second linear array antenna 3 arranged at a different height from the first linear array antenna 2 are used, but in addition to these linear array antennas, one or more other linear array antennas may be arranged at different heights to perform angle estimation of the arrival wave using the AF method. Even if the linear array antenna is configured in this way, the angle estimation of the arrival wave in the two-dimensional direction can be performed with high accuracy using the AF method.

[0111] Figure 4 1 is a block diagram showing a schematic configuration of an FMCW (Frequency Modulated Continuous Wave) radar device 11 according to one embodiment of the present invention, which is configured using the above-mentioned receiving device 1. Figure 1 The same or corresponding parts are denoted by the same reference numerals, and description thereof is omitted.

[0112] The radar device 11 is configured to include an RF (Radio Frequency) signal generator 12, a first linear array antenna 2 and a second linear array antenna 3 constituting a transmission antenna Tx and a reception antenna Rx, a mixer unit 13, a distance estimation unit 14, and a computing device 4 constituting an angle estimation unit (an azimuth phase difference first estimation unit 4a, an azimuth phase difference second estimation unit 4b, an arrival wave signal first estimation unit 4c, an arrival wave signal second estimation unit 4d, an elevation phase difference estimation unit 4e, and an arrival direction two-dimensional estimation unit 4f). Here, the first linear array antenna 2, the second linear array antenna 3, and the computing device 4 constitute the above-mentioned receiving device 1.

[0113] The RF signal generator 12 is a transmission signal generator that generates a transmission signal, and is composed of a voltage controlled oscillator or the like. The transmission antenna Tx radiates a transmission signal such as a millimeter wave generated by the RF signal generator 12, and transmits it to a target object (not shown) as a frequency-modulated continuous wave. The first linear array antenna 2 and the second linear array antenna 3 receive reflected waves of the transmission wave reflected by the target object. Each mixer unit 13 mixes the transmission signal transmitted by the transmission antenna Tx and the first reception signals x(0), x(1), x(2), x(3) and the second reception signals x(4), x(5), x(6), x(7) of the reflected waves received by the first linear array antenna 2 and the second linear array antenna 3, respectively, and converts them into an intermediate frequency signal IF.

[0114] The distance estimation unit 14 calculates the distance R to the target object based on the frequency of the intermediate frequency signal IF converted by the mixer unit 13. The calculation device 4 calculates the distance R to the target object based on the elevation angles of the arrival directions of the arrival waves P and Q estimated as described above. The azimuth angle θ is used to estimate the position of the target object in two dimensions.

[0115] According to this embodiment, it is possible to provide a method for estimating the elevation angle of a target object with high accuracy. The FMCW radar device 11 estimates the three-dimensional position of the target object based on the two-dimensional directional angle of the azimuth angle θ.

[0116] In addition, in the radar device 11 of the present embodiment, the case where there is one transmitting antenna Tx and eight receiving antennas Rx is described, but the number is not limited to this. Figure 5 As shown in the MIMO radar device 15, it is configured with m transmitting antennas Tx and n receiving antennas Rx. Figure 5 In, with Figure 4 In this case, the receiving antenna Rx is constituted by the first linear array antenna 2 and the second linear array antenna 3 having different heights, thereby providing a radar device 11 that can accurately estimate the elevation angle of the target object. The MIMO radar device 15 estimates the three-dimensional position of the target object based on the two-dimensional directional angle of the azimuth angle θ.

[0117] Figure 6 This is a diagram showing a schematic configuration of a vehicle 16 according to an embodiment of the present invention that is configured using the above-described radar device 11 or radar device 15 .

[0118] In the vehicle 16, the radar device 11 or the radar device 15 is installed at an appropriate position, in the present embodiment, in front of the vehicle 16. The transmission wave s transmitted from the transmission antenna Tx of the radar device 11 or 15 reaches the target 17 and is received as a reflected wave r by the first linear array antenna 2 and the second linear array antenna 3. The computing device 4 constituting the angle estimation unit estimates the elevation angle of the arrival direction of the reflected wave r based on the azimuth phase difference u and the elevation phase difference v between the antennas. The distance estimation unit 14 estimates the distance R to the target object 17 based on the elevation angle of the arrival direction of the reflected wave r estimated by the radar devices 11 and 15. The three-dimensional position of the target object 17 is inferred by using the azimuth angle θ and the distance R to the target object 17 .

[0119] According to the vehicle 16 of the present embodiment, it is possible to estimate the elevation angle of the target object with high accuracy. and the two-dimensional direction angle of the azimuth angle θ, and determine the three-dimensional position of the target object 17 around the vehicle 16.

[0120] Figure 7 This is a diagram showing a schematic configuration of a communication system 41 according to an embodiment of the present invention that is configured using the above-described receiving device 1 .

[0121] The communication system 41 includes a base station 42 and mobile devices such as a mobile phone 43. The transmission waves s1, s2, s3, etc. transmitted from the base station 42 are reflected by a building 44, etc., and reach the mobile phone 43 from various directions. The base station 42 is provided with an angle estimation unit composed of the above-mentioned receiving device 1, a transmission unit that transmits the transmission waves s1, s2, s3, etc., and a receiving unit composed of the above-mentioned receiving device 1 that receives the reception waves r1, r2, r3, etc. received from the mobile phone 43. The angle estimation unit estimates the elevation angle of the arrival direction of the arrival wave based on the elevation angle of the arrival direction of the arrival wave. The angle of the position of the mobile phone 43 that transmits the arrival wave is estimated in two dimensions using the azimuth angle θ. The transmitting unit performs beamforming toward the angle estimated by the angle estimation unit to perform directivity control to improve the transmission output of the transmission waves s1, s2, s3, etc. that are transmitted toward the direction of the mobile phone 43. The receiving unit performs beamforming toward the angle estimated by the angle estimation unit to perform directivity control to improve the reception sensitivity of the reception waves r1, r2, r3, etc. that are received from the direction of the mobile phone 43.

[0122] According to the communication system 41 of this embodiment, the angle estimation unit of the base station 42 is used to estimate the elevation angle. The angle of the position of the mobile phone 43 that transmits the arrival wave is estimated with high accuracy in the two-dimensional direction of the azimuth angle θ, and the directivity control of the transmission output of the transmission waves s1, s2, s3, etc. is performed in the transmission unit to increase the estimated angle, so that the signal can be efficiently transmitted from the base station 42 to the mobile phone 43. Therefore, even if the mobile phone 43 that transmits the arrival wave is located at a distant position, the transmission signal can be reliably transmitted to the mobile phone 43. In addition, the reception level of the transmission signal received at the mobile phone 43 can be increased, and reliable communication with a good SN ratio can be achieved.

[0123] In addition, according to the communication system 41 of this embodiment, by using the angle estimation unit, The angle of the location of the mobile phone 43 that transmits the arrival wave is estimated with high accuracy in the two-dimensional direction of the azimuth angle θ, and the directivity control is performed in the receiving unit to improve the reception sensitivity of the reception waves r1, r2, r3, etc. toward the estimated angles, thereby improving the reception sensitivity of the signal received from the mobile phone 43 at the base station 42. Therefore, even if the mobile phone 43 that transmits the arrival wave is located at a distant location, the transmission signal transmitted from the mobile phone 43 can be reliably received at the base station 42, and reliable communication with a good SN ratio can be achieved.

[0124] In addition, in the above-mentioned embodiment, a case is described in which an angle inference unit composed of a receiving device 1, a transmitting unit that transmits transmitting waves s1, s2, s3..., and a receiving unit composed of a receiving device 1 that receives receiving waves r1, r2, r3... are set in the base station 42, but it can also be configured so that these components are set on the side of a mobile device such as a mobile phone 43.

[0125] That is, the mobile phone 43 is provided with an angle estimation unit including the above-mentioned receiving device 1, a transmission unit for transmitting transmission waves s1, s2, s3, etc., and a reception unit including the above-mentioned receiving device 1 for receiving reception waves r1, r2, r3, etc. received from the base station 42. The angle estimation unit estimates the elevation angle of the arrival direction of the arrival wave based on the elevation angle of the arrival direction. The angle of the position of the base station 42 where the arrival wave is transmitted is estimated in two dimensions using the azimuth angle θ. The transmitting unit performs beamforming toward the angle estimated by the angle estimation unit to perform directivity control to improve the transmission output of the transmission waves s1, s2, s3, etc. transmitted in the direction of the base station 42. The receiving unit performs beamforming toward the angle estimated by the angle estimation unit to perform directivity control to improve the reception sensitivity of the reception waves r1, r2, r3, etc. received from the direction of the base station 42.

[0126] According to this structure, by using the angle estimation unit of the mobile phone 43, The angle estimation of the position of the base station 42 that transmits the arrival wave is performed with high accuracy in the two-dimensional direction of the azimuth angle θ, and the directivity control of the transmission output of the transmission waves s1, s2, s3, etc. is performed in the transmission unit to increase the estimated angle, so that the signal can be efficiently transmitted from the mobile phone 43 to the base station 42. Therefore, even if the base station 42 that transmits the arrival wave is located at a distant position, the transmission signal can be reliably transmitted to the base station 42. In addition, the reception level of the transmission signal received at the base station 42 can be increased, and reliable communication with a good SN ratio can be achieved.

[0127] In addition, according to this configuration, by using the angle estimation unit, The angle of the location of the base station 42 that transmits the arrival wave is estimated with high accuracy in the two-dimensional direction of the azimuth angle θ, and the directivity control is performed at the receiving unit of the mobile phone 43 to improve the reception sensitivity of the reception waves r1, r2, r3, etc. toward the estimated angle, so that the reception sensitivity of the signal received from the base station 42 at the mobile phone 43 can be improved. Therefore, even if the base station 42 that transmits the arrival wave is located at a distant location, the transmission signal transmitted from the base station 42 can be reliably received at the mobile phone 43, and reliable communication with a good SN ratio can be achieved.

[0128] Figure 8 (a) is a diagram showing a schematic configuration of a position detection system 51 according to an embodiment of the present invention, which is configured using the above-mentioned receiving device 1. Figure 8 Middle pair and Figure 1 The same or corresponding parts are denoted by the same reference numerals, and description thereof is omitted.

[0129] The position detection system 51 includes a plurality of transmitters 53 installed on each target 52 and outputting transmission waves s1, s2, ..., and the above-mentioned receiving device 1 for receiving the transmission waves s1, s2, ... outputted from each transmitter 53 as arrival waves at the first linear array antenna 2 and the second linear array antenna 3. The receiving device 1 calculates the elevation angle of the arrival direction of each arrival wave according to the estimated elevation angle of the arrival direction of each arrival wave. and the azimuth angle θ, and the angle of the position of each target 52 is estimated in the two-dimensional direction.

[0130] According to this embodiment, it is possible to provide The position detection system 51 performs angular estimation of the position of each target 52 in the two-dimensional direction of the azimuth angle θ with high accuracy.

[0131] According to the present embodiment, for example, as shown in (b) of the figure, two receiving devices 1 are provided, and the elevation angles of the targets 52 estimated by the receiving devices 1 are respectively measured in two-dimensional directions based on the transmission waves s1, s2, etc. emitted by the transmitter 53. The angle estimation of the azimuth angles θ1 and θ2 can be used to perform position estimation in the AOA (Angle of Arrival) method. That is, the three-dimensional position of the target 52 can be estimated with high accuracy based on the intersection position of the directions D1 and D2 estimated by each receiving device 1. In addition, there is no need to have two receiving devices 1, and even if there is only one receiving device 1, the two-dimensional position of the target 52 can be detected with high accuracy.

[0132] Description of Reference Numerals

[0133] 1...receiving device; 2...first linear array antenna; 20-23...first receiving antenna; 3...second linear array antenna; 30-33...second receiving antenna; 4...computing device; 4a...first azimuth phase difference inference unit; 4b...second azimuth phase difference inference unit; 4c...first arrival signal inference unit; 4d...second arrival signal inference unit; 4e...elevation phase difference inference unit; 4f...two-dimensional arrival direction inference unit; 5...filter; 11...FMCW radar device; 12...RF signal generator; 13...mixer unit; 14...distance inference unit; 15...MIMO radar device; 16...vehicle; 17...target; 41...communication system; 42...base station; 43...mobile phone (mobile device); 44...building; 51...position detection system; 52...target; 53...transmitter.

Claims

1. A receiving device, comprising: A first linear array antenna, comprising a plurality of first receiving antennas, the number of which is at least one more than the number of arrival waves, arranged on a straight line at equal intervals, each of the first receiving antennas receiving a first reception signal having a phase that is different from the phase of each arrival wave received by a reference first receiving antenna that is one of the plurality of first receiving antennas, and having an amplitude corresponding to each arrival wave; a second linear array antenna, wherein a plurality of second receiving antennas, which are at least one more than the number of the arrival waves, are arranged on a straight line parallel to the straight line at intervals equal to the intervals at a height different from that of the first linear array antenna, wherein each of the second receiving antennas receives a second reception signal, the second reception signal having a phase that is different from the phase of each of the arrival waves by a phase difference corresponding to the height received by a reference second receiving antenna that is one of the plurality of second receiving antennas, and having an amplitude corresponding to each of the arrival waves; a first azimuth phase difference estimation unit that estimates the azimuth phase difference of each of the arrival waves between each of the first receiving antennas by an AF method based on the phase at the zero point of a transfer function that divides a first reception signal group consisting of first reception signals into a plurality of groups and inputs the first reception signals so that each output for each of the input first reception signal groups is 0, wherein the first reception signals are signals received by the first reception antennas and the number of the signals is one more than the number of the arrival waves; a second azimuth phase difference estimation unit for estimating the azimuth phase difference of each of the arrival waves between each of the second receiving antennas by an AF method based on the phase at the zero point of a transfer function in which a second reception signal group consisting of second reception signals is divided into a plurality of groups and input, and each output for each of the second reception signal groups input is set to 0, wherein the second reception signals are signals received by the second reception antennas and the number of the second reception signals is one more than the number of the arrival waves; The first arrival wave signal estimation unit estimates the amplitudes A1, A2 and the phases α1, α2 of the signals S1, S2 of the arrival waves reaching the first reference receiving antenna according to the azimuth phase differences u1, u2 of the arrival waves between the first receiving antennas estimated by the first azimuth phase difference estimation unit and the first received signals x(0), x(1), x(2), x(3) by using the following formula (7); [Formula 7] The second arrival wave signal estimation unit estimates the amplitudes A1 and A2 and the phases α1+u1+v1 and α2+u2+v2 of the signals S1′ and S2′ of the arrival waves reaching the reference second receiving antenna according to the following formula (8), based on the azimuth phase differences u1 and u2 of the arrival waves between the second receiving antennas estimated by the second azimuth phase difference estimation unit and the second received signals x(4), x(5), x(6), and x(7); [Formula 8] An elevation phase difference estimation unit estimates a phase difference corresponding to the height as elevation phase differences v1 and v2 for each of the above-mentioned arrival waves according to the signals of the above-mentioned arrival waves estimated by the above-mentioned arrival wave signal first estimation unit to have arrived at the above-mentioned reference first receiving antenna and the signals of the above-mentioned arrival waves estimated by the above-mentioned arrival wave signal second estimation unit to have arrived at the above-mentioned reference second receiving antenna by using the following formula (9); [Formula 9] as well as The arrival direction two-dimensional estimation unit estimates the elevation angle of the arrival direction of each of the above-mentioned arrival waves by the following formula (10) based on the elevation phase difference estimated by the above-mentioned elevation phase difference estimation unit. Based on the azimuth phase difference estimated by the first azimuth phase difference estimation unit or the second azimuth phase difference estimation unit, the azimuth angles θ1 and θ2 of the arrival direction of each of the arrival waves are estimated by the following formula (11): [Formula 10] [Formula 11] 2. A radar device, comprising: A sending signal generator, generating a sending signal; a transmitting antenna for transmitting, as a transmitting wave, a transmitting signal generated by the transmitting signal generator; an angle estimation unit that estimates the angle of the position of the target object in two-dimensional directions based on the elevation angle and the azimuth angle of the arrival direction of the arrival wave estimated by the receiving device according to claim 1; and The distance estimation unit estimates the distance to the target object.

3. The radar device according to claim 2, which is a FMCW radar device, characterized in that: A mixer is provided for mixing a reception signal of a reflected wave which is a transmission wave transmitted from the transmission antenna as a frequency modulated continuous wave and is reflected by a target object and received by the first linear array antenna and the second linear array antenna in the reception device and a transmission signal of the transmission wave transmitted from the transmission antenna, and converting the mixed signals into an intermediate frequency signal. The distance estimation unit estimates the distance to the target object based on the frequency of the intermediate frequency signal converted by the mixer unit.

4. A vehicle comprising the radar device according to claim 2 or 3.

5. A communication system, The base station or mobile device has: an angle estimation unit that estimates the angle of the position of the mobile device or the base station that transmits the arrival wave in a two-dimensional direction based on the elevation angle and the azimuth angle of the arrival direction of the arrival wave estimated by the receiving device according to claim 1; and The transmitting unit performs beamforming toward the angle estimated by the angle estimating unit to perform directivity control to improve the transmission output of the transmission wave transmitted in the direction where the mobile device or the base station is located.

6. A communication system, The mobile device or base station has: an angle estimation unit that estimates the angle of the position of the base station or the mobile device that transmits the arrival wave in a two-dimensional direction based on the elevation angle and the azimuth angle of the arrival direction of the arrival wave estimated by the receiving device according to claim 1; and The receiving unit performs directivity control to improve the reception sensitivity of the reception wave received from the direction where the above-mentioned base station or the above-mentioned mobile device is located by performing beamforming toward the angle estimated by the above-mentioned angle estimation unit.

7. A position detection system, comprising: a plurality of transmitters installed at respective targets and outputting transmission waves; and The angle estimation unit estimates the angle of each target position in two-dimensional directions based on the elevation angle and azimuth angle of the arrival direction of each arrival wave estimated by the receiving device according to claim 1, wherein: The receiving device according to claim 1 receives the transmission waves output from the transmitters as the arrival waves.

Images