Communication Equipment

Abstract

To provide a new and improved communication device that can estimate the arrival angle of a signal with higher accuracy.SOLUTION: A communication device includes at least a first antenna and a second antenna that transmit and receive a signal conforming to a prescribed communication standard. The first antenna and the second antenna are arranged so that an absolute value of phase difference between the antennas becomes small when the signal is received from a first region by comparing when the signal is received from the first region where estimation accuracy of a signal arrival angle is desired to be improved with when the signal is received from a second region, which is a region other than the first region, based on relationship of the signal arrival angle and phase difference between the antennas.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a communication device. [Background technology]

[0002] In recent years, a technology has been developed in which one device estimates the position of another device based on the results of transmitting and receiving signals between the devices. For example, Patent Document 1 discloses a technology in which an ultra-wide band (UWB) receiver estimates the angle of arrival of a wireless signal transmitted from a UWB transmitter using an ultra-wide band (UWB) signal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2015 / 176776 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-described system, the accuracy of estimating the arrival angle of a wireless signal may be affected by the relative positions of the multiple antennas.

[0005] Therefore, the present invention has been made in consideration of the above problems, and an object of the present invention is to provide a new and improved communication device capable of estimating the arrival angle of a signal with higher accuracy. [Means for solving the problem]

[0006] In order to solve the above problem, according to one aspect of the present invention, a communication device is provided, comprising at least a first antenna and a second antenna for transmitting and receiving signals that comply with a prescribed communication standard, wherein the first antenna and the second antenna are arranged so that, based on the relationship between the signal arrival angle and the phase difference between the antennas, a comparison is made between a case where the signal is received from a first region in which it is desired to improve the estimation accuracy of the signal arrival angle and a case where the signal is received from a second region that is a region other than the first region, and the absolute value of the phase difference between the antennas is smaller when the signal is received from the first region. Effect of the Invention

[0007] As described above, according to the present invention, it is possible to estimate the arrival angle of a signal with higher accuracy. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram showing an example of the configuration of a system 1 according to this embodiment. [Diagram 2] 1 is an explanatory diagram for explaining an outline of estimating a positional relationship between the vehicle-mounted device 10 and the portable device 20 based on a signal w1 transmitted and received between the vehicle-mounted device 10 and the portable device 20. FIG. [Diagram 3] 1 is an explanatory diagram for explaining an outline of estimating a positional relationship between the vehicle-mounted device 10 and the portable device 20 based on a signal w1 transmitted and received between the vehicle-mounted device 10 and the portable device 20. FIG. [Figure 4] FIG. 2 is a sequence diagram for explaining an example of processing relating to distance estimation and angle estimation executed in the system 1 according to the present embodiment. [Diagram 5] 1 is a graph showing the relationship between the phase difference between antennas and the radio wave arrival angle. [Figure 6] FIG. 2 is an explanatory diagram for explaining the arrangement of antennas according to the embodiment. [Figure 7] FIG. 2 is an explanatory diagram for explaining an example of the flow of operation processing of the system 1 according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this specification and the drawings, components having substantially the same functional configurations are designated by the same reference numerals, and duplicated explanations will be omitted.

[0010] <1. Embodiment> <<1.1. System configuration example>> First, a schematic configuration of a system 1 according to the present embodiment will be described with reference to Fig. 1. Fig. 1 is a block diagram showing an example of the configuration of the system 1 according to the present embodiment.

[0011] As shown in FIG. 1, a system 1 according to this embodiment includes a vehicle-mounted device 10 and a portable device 20.

[0012] (Onboard device 10) The vehicle-mounted device 10 according to the present embodiment is an example of a communication device. The vehicle-mounted device 10 according to the present embodiment may be, for example, a communication unit mounted on a moving body in which a user is permitted to ride (for example, a vehicle owned by the user or a vehicle temporarily loaned to the user).

[0013] As shown in FIG. 1, the vehicle-mounted device 10 according to this embodiment includes a control unit 110, a communication unit 120, and a processing unit .

[0014] The control unit 110 controls the overall operation of the vehicle-mounted device 10. For example, the control unit 110 controls the transmission and reception of wireless signals that comply with a prescribed communication standard. More specifically, the control unit 110 controls the transmission and reception of ultra-wideband signals (hereinafter referred to as UWB signals).

[0015] Although the UWB signal is given as an example of a wireless signal conforming to a prescribed communication standard, the wireless signal conforming to the prescribed communication standard is not limited to the UWB signal. For example, the prescribed communication standard according to the present embodiment includes various communication standards capable of measuring the propagation time of a signal between wireless communication devices.

[0016] Moreover, the functions of the control unit 110 according to the present embodiment are realized by, for example, various processors.

[0017] The communication unit 120 has functions as a first antenna, a second antenna, and a third antenna for transmitting and receiving wireless signals conforming to a prescribed communication standard. For example, the communication unit 120 receives a Poll (Polling) signal transmitted from the portable device 20. After receiving the Poll signal, the communication unit 120 transmits a Resp (Response) signal to the portable device 20 under the control of the control unit 110. The communication unit 120 also receives a Final signal transmitted from the portable device 20 as a response to the Resp signal.

[0018] The processing unit 130 executes a process of estimating the positional relationship between the vehicle-mounted device 10 and the portable device 20, for example, based on a signal transmitted and received between the vehicle-mounted device 10 and the portable device 20. For example, the processing unit 130 may execute a process of estimating an arrival angle of a signal based on a received signal. The processing unit 130 may also execute a process of estimating a distance between the vehicle-mounted device 10 and the portable device 20 based on a transmitted and received signal. The processing unit 130 may also estimate a three-dimensional position of the portable device 20 based on the estimated arrival angle of the signal and the distance between the vehicle-mounted device 10 and the portable device 20.

[0019] Although details regarding the process of estimating the positional relationship between the devices will be described later, the processing unit 230 included in the portable device 20 may execute the process of estimating the positional relationship between the vehicle-mounted device 10 and the portable device 20. In this case, the communication unit 120 may transmit, for example, information required to estimate the positional relationship between the devices to the portable device 20.

[0020] (Portable device 20) The portable device 20 according to the present embodiment may be, for example, an electronic key, a smartphone, a wearable terminal, etc. The portable device 20 according to the present embodiment is, for example, carried by a user, and transmits and receives wireless communications conforming to prescribed communications between the portable device 20 and an in-vehicle device 10 mounted on a moving body such as a vehicle used by the user.

[0021] As shown in FIG. 1, the portable device 20 according to the present embodiment includes a control unit 210, a communication unit 220, and a processing unit 230.

[0022] The control unit 210 controls the overall operation of the portable device 20. For example, the control unit 210 controls the transmission and reception of wireless signals that comply with a prescribed communication standard.

[0023] The communication unit 220 transmits and receives wireless signals in accordance with a prescribed communication standard, for example. For example, the communication unit 220 transmits a Poll signal to the vehicle-mounted device 10. The communication unit 220 also receives a Resp signal from the communication unit 120 included in the vehicle-mounted device 10. The communication unit 220 also transmits a Final signal in response to the Resp signal under the control of the control unit 210.

[0024] The processing unit 230 executes a process of estimating the positional relationship between the vehicle-mounted device 10 and the portable device 20 based on, for example, signals transmitted and received between the vehicle-mounted device 10 and the portable device 20 .

[0025] Next, an example of a process for estimating a positional relationship will be described with reference to FIG.

[0026] <1.2. Estimation of positional relationship> 2 and 3 are explanatory diagrams for explaining an example of a process for estimating the positional relationship between the vehicle-mounted device 10 and the portable device 20 based on a signal w1 transmitted and received between the vehicle-mounted device 10 and the portable device 20. FIG.

[0027] As shown in Fig. 2, the vehicle-mounted device 10 is disposed, for example, on the ceiling surface of the vehicle V1, and has a plurality of antennas. Note that the scale of the vehicle-mounted device 10 and each antenna provided in the vehicle-mounted device 10 is illustrated large for the purpose of explanation, and may differ from the actual scale. Here, the configuration of the antenna provided in the vehicle-mounted device 10 will be described with reference to Fig. 3.

[0028] 3, the vehicle-mounted device 10 has, for example, an antenna A1, an antenna A2, an antenna A3, and an antenna A4. The antenna A3 is disposed so that a line connecting the antennas A1 and A3 is perpendicular to a line connecting the antennas A1 and A2. The antenna A4 is disposed so that a line connecting the antennas A2 and A4 is perpendicular to a line connecting the antennas A1 and A2.

[0029] In addition, in the local coordinate system of the vehicle-mounted device 10 according to this embodiment, for example, when antenna A1 is the origin, the direction of the straight line connecting antennas A1 and A2 is the X-axis, the direction in which the straight line connecting antennas A1 and A3 is perpendicular to the X-axis is the Y-axis, and the vertical direction of antenna A1 is the Z-axis.

[0030] For example, antenna A1 may be a first antenna, antenna A2 may be a second antenna, and antenna A3 may be a third antenna.

[0031] In this specification, unless otherwise specified, the straight line connecting antennas A1 and A2 is described as the X-axis, and the straight line connecting antennas A1 and A3 is described as the Y-axis, but the definition of the coordinate axes is not limited to this example. For example, the local coordinate system of the vehicle-mounted device 10 may have antenna A4 as the origin, a straight line connecting antennas A3 and A4 as the X-axis, a straight line connecting antennas A2 and A4 as the Y-axis, and a vertical direction of antenna A4 as the Z-axis.

[0032] 3, the interval between adjacent antennas may be, for example, 1 / 2 wavelength, but may be other intervals. The arrangement shape of the four antennas is not limited to a square, and may be a parallelogram, a trapezoid, a rectangle, or any other shape.

[0033] In addition, the number of antennas is not limited to four. For example, the number of antennas is at least two, so the main claim specifies at least a first antenna and a second antenna. The above describes the configuration of the antenna of the vehicle-mounted device 10.

[0034] Returning now to FIG. 2, an example of position information included in the positional relationship between the vehicle-mounted device 10 and the portable device 20 will be described. As shown in FIG. 2, the position information includes distance information between the vehicle-mounted device 10 and the portable device 20. For example, the distance information includes a distance R from the origin of the local coordinate system of the vehicle-mounted device 10 to the portable device 20. The distance R corresponds to the distance between the vehicle-mounted device 10 and the portable device 20. More specifically, the distance R is the distance between an antenna (e.g., antenna A1) located at the origin of the local coordinate system of the vehicle-mounted device 10 and an antenna of the same type provided on the portable device 20. Note that the distance R is estimated based on a signal transmitted and received between the antenna located at the origin of the local coordinate system and the portable device 20.

[0035] The position information also includes angle information at which the portable device 20 is located. The angle information includes, for example, an angle θ between the X-axis and the signal w1 transmitted by the portable device 20, and an angle Φ between the Y-axis and the signal w1 transmitted by the portable device 20. The angles θ and Φ are the angles of arrival of the signal w1, respectively.

[0036] An example of a flow of estimating the positional relationship between the vehicle-mounted device 10 and the portable device 20 according to this embodiment will be described below.

[0037] (1) Distance Estimation The processing unit 130 of the vehicle-mounted device 10 or the processing unit 230 of the portable device 20 performs distance measurement processing. The distance measurement processing is processing for estimating the distance between the vehicle-mounted device 10 and the portable device 20. In other words, the distance measurement processing is processing for estimating the distance R shown in Fig. 2. The distance measurement processing includes transmitting and receiving a distance measurement signal and estimating the distance R based on the time required for transmitting and receiving the distance measurement signal.

[0038] In the distance measurement process, a plurality of distance measurement signals may be transmitted and received between the vehicle-mounted device 10 and the portable device 20. Of the plurality of distance measurement signals, a distance measurement signal transmitted from one device to another device is referred to as a Poll signal. A distance measurement signal transmitted in response to a Poll signal from a device that has received a Poll signal to a device that has transmitted the Poll signal is referred to as a Resp signal. A distance measurement signal transmitted in response to a Resp signal from a device that has received a Resp signal to a device that has transmitted the Resp signal is referred to as a Final signal.

[0039] (2) Arrival angle estimation The processing unit 130 of the vehicle-mounted device 10 or the processing unit 230 of the portable device 20 estimates the angle θ and the angle Φ shown in Fig. 2 as the arrival angle of the signal w1. At least one of the above-mentioned distance measurement signals may be used as the signal for estimating the arrival angle. In this specification, the Final signal will be described as the signal for estimating the arrival angle.

[0040] Hereinafter, an example of processing relating to distance estimation and arrival angle estimation will be described with reference to FIG.

[0041] Fig. 4 is a sequence diagram for explaining an example of processing related to distance estimation and arrival angle estimation executed in the system 1 according to this embodiment. In Fig. 4, the antenna of the portable device 20 is referred to as Tag.

[0042] First, the Tag of the portable device 20 transmits a Poll signal to the antenna A1 of the vehicle-mounted device 10 (S102).

[0043] Next, the antenna A1 of the vehicle-mounted device 10 transmits a Resp signal to the Tag of the portable device 20 in response to the Poll signal (S104).

[0044] Then, the Tag included in the portable device 20 transmits a Final signal to the antennas A1, A2, A3 and A4 included in the vehicle-mounted device 10 in response to the Resp signal (S106).

[0045] Here, the time length from when the portable device 20 transmits the Poll signal to when it receives the Resp signal is defined as time length T1, the time length from when it receives the Resp signal to when it transmits the Final signal is defined as time length T2, the time length from when the vehicle-mounted device 10 receives the Poll signal to when it transmits the Resp signal is defined as time length T3, and the time length from when it transmits the Resp signal to when it receives the Final signal is defined as time length T4.

[0046] The distance R may be calculated using each of the time lengths described above. For example, the processing unit 130 of the vehicle-mounted device 10 calculates the signal propagation time τ using the time length T1, the time length T2, the time length T3, and the time length T4. For example, the processing unit 130 may calculate the signal propagation time τ using the following formula. τ=(T1×T4−T2×T3) / (T1+T2+T3+T4) (Formula 1)

[0047] Then, the processing unit 130 may estimate the distance R between the vehicle-mounted device 10 and the portable device 20 by multiplying the calculated signal propagation time τ by the known signal speed.

[0048] Although an example has been described in which the processing unit 130 estimates the distance R between the vehicle-mounted device 10 and the portable device 20 based on the signal transmitted and received between the antenna A1 and the Tag possessed by the portable device, the antenna of the vehicle-mounted device 10 may transmit and receive signals using another antenna, or may transmit and receive signals using multiple antennas.

[0049] In addition, the Poll signal, the Resp signal, and the Final signal may be transmitted and received by any device. For example, the Poll signal may be transmitted by any antenna of the vehicle-mounted device 10. In this case, the Resp signal may be transmitted by an antenna of the portable device 20.

[0050] Furthermore, the method of calculation of the propagation time τ of a signal is not limited to that of Equation 1. For example, the propagation time of a signal can also be calculated by subtracting the time length T3 from the time length T1 and dividing the resulting time length by two.

[0051] Next, the arrival angle of the signal may be calculated from the phase difference between the Final signals received by adjacent antennas among the antennas. For example, the phase of the Final signal received by the antenna A1 may be calculated as phase P A1 The phase of the Final signal received by antenna A2 is P A2 The phase of the Final signal received by antenna A3 is P A3 The phase of the Final signal received by antenna A4 is P A4 In this case, the phase difference between adjacent antennas in the X-axis direction is Pd A12 , Pd A34 , and the phase difference Pd between adjacent antennas in the Y-axis direction A13 , Pd A24 are expressed using the following formulas, respectively.

[0052] Pd A12 =(P A2 -P A1 ) Pd A34 =(P A4 -P A3 ) Pd A13 =(P A3 -P A1 ) Pd A24 =(P A4 -P A2 ) (Formula 2)

[0053] Here, the formed angles θ and Φ are expressed by the following equations, where λ is the wavelength of the radio wave and d is the distance between the antennas. θorΦ=arccos(λ×Pd / (2πd)) (Formula 3)

[0054] Therefore, the processing unit 130 calculates the arrival angle of the signal based on Equation 2 and Equation 3 using the following equations. θ A12 =arccos(λ×(P A2 -P A1 ) / (2πd)) θ A34 =arccos(λ×(PA4 -P A3 ) / (2πd)) Φ A13 =arccos(λ×(P A3 -P A1 ) / (2πd)) Φ A24 =arccos(λ×(P A4 -P A2 ) / (2πd)) (Formula 4)

[0055] In addition, the processing unit 130 A12 and θ A34 Alternatively, the angle θ may be calculated as the average value of A12 or θ A34 Similarly, the processing unit 130 may estimate the angle θ between either one of Φ A13 and Φ A24 Alternatively, the angle Φ may be calculated as the average value of A13 or Φ A24 Alternatively, the angle Φ may be estimated as the angle Φ that forms one of the angles Φ.

[0056] Furthermore, the processing unit 130 may estimate the three-dimensional position of the portable device 20 based on the coordinate system of the vehicle-mounted device 10 using the estimated distance R and the formed angle θ or the formed angle Φ.

[0057] For example, the processing unit 130 may estimate the three-dimensional position of the portable device 20 using Equation 5. x=R×cosθ y=R×cosΦ z=√(R 2 -x 2 -y 2 ) (Formula 5)

[0058] The flow of estimating the positional relationship between the vehicle-mounted device 10 and the portable device 20 according to this embodiment has been described above.

[0059] <<1.3. Estimation error of angle of arrival>> As described above, in order for the processing unit 130 to estimate the three-dimensional position of the portable device 20, it is necessary to estimate the formed angles θ and Φ, that is, the radio wave arrival angles of the signals, with higher accuracy.

[0060] However, the more the formed angles θ and Φ deviate from 90 degrees, the larger the estimation error may become. More specifically, phase noise may be superimposed on the phase of the received signal, and an estimation error in the signal arrival angle may occur due to a phase shift of the signal caused by the phase noise. The more the signal arrival angle deviates from 90 degrees, the larger the estimation error in the signal arrival angle due to the phase shift may become.

[0061] Fig. 5 is a graph showing the relationship between the phase difference between antennas and the radio wave arrival angle, in which the vertical axis represents the phase difference between adjacent antennas and the horizontal axis represents the radio wave arrival angle of the signal.

[0062] In Fig. 5, for example, it is assumed that phase noise is superimposed on the signals received by two antennas, causing a phase difference Δpd between the signals received by the two antennas. When this phase difference Δpd occurs, as shown in Fig. 5, the closer to 90 degrees the angle is, the smaller the estimation error of the radio wave arrival angle becomes, and the farther away from 90 degrees the greater the estimation error of the radio wave arrival angle becomes.

[0063] For example, when a signal arrives from a certain direction on the Y axis (that is, the radio wave arrival angle is 90 degrees), the processing unit 130 can estimate the formed angle θ with high accuracy.

[0064] On the other hand, since the two adjacent antennas used to calculate the angle Φ are each located on the Y axis, when a signal arrives from a certain direction on the Y axis (i.e., the radio wave arrival angle is 0 degrees or 180 degrees), the processing unit 130 can estimate the angle Φ that is larger than the angle θ and includes an estimation error caused by a phase shift.

[0065] That is, there is a trade-off between the angle θ and the angle Φ, and improving the estimation accuracy of one of them may result in a decrease in the estimation accuracy of the other.

[0066] Therefore, the vehicle-mounted device 10 according to this embodiment is a device in which the antenna arrangement has been ingeniously designed to reduce the effects of estimation errors caused by the phase shifts of the angles θ and Φ in areas where the estimation accuracy is desired to be improved.

[0067] Specifically, a first region where it is desired to improve the estimation accuracy of the signal arrival angle and a second region other than the first region are defined, and adjacent antennas are arranged so that the absolute value of the phase difference between the antennas when they receive a signal from the first region is smaller than the absolute value of the phase difference between the antennas when they receive a signal from the second region.

[0068] For example, antennas A1 and A2 are arranged so that the absolute value of the phase difference between the antennas when a signal is received from the first region is smaller than the absolute value of the phase difference between the antennas when a signal is received from the first region, based on the relationship between the radio wave arrival angle and the phase difference between the antennas described above. This allows the processing unit 150 to reduce the influence of the phase shift and calculate the angle θ with high accuracy.

[0069] Moreover, the antenna A3 is arranged so that the line connecting the antenna A1 and the antenna A3 is perpendicular to the line connecting the antenna A1 and the antenna A2. In this case, the antenna A1, the antenna A2, and the antenna A3 are arranged so that the absolute value of the inter-antenna phase difference between the antenna A1 and the antenna A2 and the antenna A1 and the antenna A3 when the signal is received from the first area is reduced by comparing the signal received from the first area with the signal received from the second area based on the relationship between the radio wave arrival angle and the phase difference between the antennas A1 and A2 and the antenna A1 and A3 when the signal is received from the first area. This allows the processing unit 150 to reduce the influence based on the phase shift and to calculate the angle θ and the angle Φ with high accuracy. Hereinafter, an example of the arrangement of multiple antennas will be described in more detail with reference to FIG. 6.

[0070] <<1.4. Antenna placement>> Fig. 6 is an explanatory diagram for explaining the arrangement of antennas according to this embodiment. First, the first area for which the arrival angle of a signal is to be estimated is set to two boarding and alighting positions of a vehicle V1. Here, the two boarding and alighting positions may be the driver's door D1 and the passenger's door P1 as shown in Fig. 6.

[0071] The vehicle-mounted device 10 may also be mounted at the center of a straight line connecting two boarding and disembarking positions. For example, if the length connecting the driver's door D1 and the passenger's door P1 is L, the center of the vehicle-mounted device 10 may be located at the center position (1 / 2L) of L. This allows the processing unit 130 to estimate the arrival angle of a signal with higher accuracy in either of the two regions where the arrival angle of a signal is to be estimated.

[0072] 6, when a signal w1 is received from the first region, the antennas are arranged so that the angles θ and Φ, which are the angles of arrival of the signal w1, are not close to 0 degrees or 180 degrees. More specifically, the antennas may be arranged so that the angles θ and Φ are close to approximately 45 degrees and approximately 135 degrees, respectively. This allows the processing unit 130 to estimate the angle of arrival of the signal w1 with high accuracy when the signal is received from the first region.

[0073] In Fig. 6, the first region is in the left-right direction of the vehicle V1, but the present invention is not limited to this example. The first region may be in any direction, for example, in the four corner directions of the vehicle, or in the front-rear direction of the vehicle. In addition, when the first region for which the arrival angle of a signal is to be estimated changes, the control unit 110 of the vehicle-mounted device 10 may control the vehicle-mounted device 10 to rotate according to the changed region.

[0074] Furthermore, a plurality of vehicle-mounted devices 10 may be provided at different positions on the vehicle V1. Each of the vehicle-mounted devices 10 mounted at different positions on the vehicle V1 estimates the arrival angle of a signal, thereby improving the estimation accuracy in all directions.

[0075] The above describes the arrangement of the antennas of the vehicle-mounted device 10 according to this embodiment. Next, an example of the operation process of the system 1 according to this embodiment will be described with reference to FIG.

[0076] <2. Operation processing example> 7 is an explanatory diagram for explaining an example of the flow of operation processing of the system 1 according to this embodiment. First, the communication unit 120 receives a Poll signal from the portable device 20 (S202).

[0077] Next, the communication unit 120 transmits a Resp signal to the portable device 20 as a response to the Poll signal (S204).

[0078] Next, the communication unit 120 receives a Final signal from the portable device 20 as a response to the transmitted Resp signal (S206).

[0079] Then, the processing unit 130 calculates the distance between the vehicle-mounted device 10 and the portable device 20, that is, the measured distance value, based on the signals transmitted and received in S202 to S206 (S208).

[0080] Then, the processing unit 130 calculates the arrival angle of the Final signal based on the phase difference between each of the Final signals received by the antennas A1 to A4 in S206 and adjacent antennas (S210).

[0081] Next, the processing unit 130 estimates the three-dimensional position of the portable device 20 based on the calculated distance measurement value and the arrival angle of the signal (S212).

[0082] Then, the processing unit 130 judges whether or not the three-dimensional position of the portable device 20 estimated in S212 satisfies a predetermined criterion. If it is judged that the predetermined criterion is satisfied (S214 / Yes), the process proceeds to S216, and if it is judged that the predetermined criterion is not satisfied (S214 / No), the vehicle-mounted device 10 ends the process.

[0083] If it is determined that the predetermined criterion is satisfied (S214 / Yes), the control unit 110 performs control related to unlocking or locking the doors of the vehicle V1 (S216), and the in-vehicle device 10 ends the process. Note that the control related to S216 may be executed by another control device.

[0084] According to the antenna arrangement and control of this embodiment, for example, the position of a user holding a portable device 20 near the boarding and disembarking position can be estimated with high accuracy, and control such as unlocking or locking the doors of the vehicle V1 can be more effectively realized.

[0085] <3. Supplementary Information> Although the preferred embodiment of the present invention has been described in detail above with reference to the accompanying drawings, the present invention is not limited to such an example. It is clear that a person having ordinary knowledge in the technical field to which the present invention pertains can conceive of various modified or altered examples within the scope of the technical ideas described in the claims, and it is understood that these also naturally belong to the technical scope of the present invention.

[0086] For example, the series of processes performed by each device described in this specification may be realized using software, hardware, or a combination of software and hardware. The programs constituting the software are stored in advance, for example, in a recording medium (non-transitory medium) provided inside or outside each device. Then, each program is loaded into a RAM when executed by a computer, for example, and executed by a processor such as a CPU. The recording medium is, for example, a magnetic disk, an optical disk, a magneto-optical disk, a flash memory, etc. Also, the computer program may be distributed, for example, via a network, without using a recording medium.

[0087] In addition, the processes described in this specification using sequence diagrams do not necessarily have to be performed in the order shown in the drawings. For example, some processing steps may be performed in parallel. In addition, additional processing steps may be adopted, and some processing steps may be omitted. [Explanation of symbols]

[0088] 10: vehicle-mounted device, 110: control unit, 120: communication unit, 130: processing unit, 20: portable device, 210: control unit, 220: communication unit, 230: processing unit

Claims

1. at least a first antenna, a second antenna, and a third antenna for transmitting and receiving signals conforming to a prescribed communication standard; Equipped with the third antenna is disposed such that a straight line connecting the first antenna and the third antenna or a straight line connecting the second antenna and the third antenna is orthogonal to a straight line connecting the first antenna and the second antenna, the first antenna, the second antenna, and the third antenna are arranged such that, based on a relationship between a signal arrival angle and a phase difference between antennas, an absolute value of the phase difference between adjacent antennas when the signal is received from a first region in which it is desired to improve the estimation accuracy of the signal arrival angle is smaller than an absolute value of the phase difference between adjacent antennas when the signal is received from a second region that is a region other than the first region. Communications equipment.

2. The present invention is used in an apparatus that is controlled based on the estimation result of the signal arrival angle, The communication device according to claim 1 .

3. Mounted on a moving vehicle, A communication device according to claim 1 or 2.

4. Two boarding and alighting positions among the boarding and alighting positions of the moving body for which the estimation accuracy is desired to be improved are set as the first region, and the vehicle is mounted at a center position of a straight line connecting the two boarding and alighting positions. The communication device according to claim 3.

5. The boarding and alighting position includes a position of a driver's door and a passenger's door of the moving body as the first area, The communication device according to claim 4.

6. Mounted on the ceiling surface of the moving body, A communication device according to any one of claims 3 to 5.

7. The transmitted and received signals are used in a calculation to estimate an angle of arrival of the signal received from another communication device. A communication device according to any one of claims 3 to 6.

8. The transmitted and received signals are used in a calculation to estimate a distance between the communication device and the other communication device. The communication device according to claim 7.

9. The estimated arrival angle of the signal and the distance between the communication device and the other communication device are used in a process of estimating a three-dimensional position of the other communication device. The communication device according to claim 8.

10. The process of estimating the three-dimensional position is used to unlock or lock a door of the moving object. The communication device according to claim 9.

11. The signal includes a radio signal conforming to ultra-wideband wireless communication. A communication device according to any one of claims 1 to 10.

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