WO2023067714A1

WO2023067714A1 - Terminal position estimating device, terminal position estimating method, and vehicle wireless device

Info

Publication number: WO2023067714A1
Application number: PCT/JP2021/038680
Authority: WO
Inventors: 貴史丸山; 周作梅田; 正信平峰
Original assignee: 三菱電機株式会社
Priority date: 2021-10-20
Filing date: 2021-10-20
Publication date: 2023-04-27
Also published as: JP7433546B2; JPWO2023067714A1

Abstract

A terminal position estimating device (1) comprises a plurality of fixed apparatuses (10) (10A), (10B) which are disposed in different positions, and each of which has a distance measurement function for estimating a distance to a terminal (20), and an angle measurement function for estimating an arrival angle of radio waves from the terminal by means of a phase difference between reception signals resulting from the radio waves from the terminal that have been received using a plurality of antennas, and which obtains estimated position information indicating an estimated position of the terminal by means of the estimated distance and the estimated arrival angle. Further, the terminal position estimating device (1) is provided with an estimated position estimating unit which combines together the estimated position information from the fixed apparatuses (10) (10A), (10B) disposed in mutually different positions, obtains a distance between estimated positions indicated by the combined estimated position information, and obtains estimated position information of the combination having the smallest obtained distance.

Description

Terminal position estimation device, terminal position estimation method, and vehicle radio device

The present disclosure relates to a terminal location estimation device and a terminal location estimation method for estimating the location of a terminal in wireless communication between a fixed device and a terminal, and a vehicle wireless device.

In a system where fixed devices and terminals communicate wirelessly, technology for estimating the position of the terminal is used. As means for estimating the position of a terminal, there are distance measurement for measuring the distance from the fixed device to the terminal and angle measurement for measuring the direction of the terminal viewed from the fixed device.

As an example of ranging, there is a method of transmitting and receiving radio waves between a terminal and a fixed device and calculating the distance from the propagation time. An example of a communication method for distance measurement is UWB (Ultra Wide Band) in the GHz band.
As an example of angle measurement, multiple receiving antennas are arranged on the fixed machine, radio waves from the terminal are received by the multiple receiving antennas arranged on the fixed machine, and the direction of the terminal is determined from the phase difference between the received incoming waves. There is a way.
Various angle measurement algorithms are shown in Non-Patent Document 1 as such methods for estimating the direction of arrival of radio waves.

The position of the terminal can be estimated by performing ranging and angle measurement with a fixed device.
In addition, a fixed device can be installed at each of a plurality of positions, the distance to the terminal can be estimated by each fixed device, and the position of the terminal can be obtained by multilateration.
Alternatively, a fixed device can be installed at each of a plurality of positions, the direction of the terminal can be estimated by each fixed device, and the position of the terminal can be obtained by triangulation.

However, when angle measurement is performed using the phases of the incoming waves obtained by each of the plurality of receiving antennas arranged in the fixed station, if there is an error in the phase of the received signal based on the incoming waves, the angle measurement will be erroneous. .
In particular, when the phase difference between multiple antennas exceeds 180° or falls below -180°, the phase difference of the received signals received by the multiple antennas folds back, and the terminal position estimation results differ from the terminal's actual position. It deviates greatly from the position.

In addition, when the distance between the multiple receiving antennas arranged in the fixed station is larger than half the wavelength of the incoming wave, even if there is no error in the phase of the received signal based on the incoming wave, the position of the received signal by the multiple receiving antennas Folding occurs in the relationship between the phase difference and the arrival angle of the incoming wave.
If the relationship between the phase difference and the arrival angle is reversed, there will be multiple arrival angle values corresponding to the phase differences, the direction of the terminal will not be uniquely determined, and the angle measurement will be erroneous.

The present disclosure has been made in view of the above points, and even if there is an error in the angle measurement due to an error in the phase of the received signal based on the incoming wave, the accuracy of estimating the position of the terminal is improved. An object of the present invention is to obtain a terminal position estimation device.

A terminal position estimation device according to the present disclosure includes a plurality of fixed stations arranged at different positions and an estimated position estimation unit, and each of the plurality of fixed stations has a ranging function for estimating a distance to a terminal, and a plurality of It has an angle measurement function that estimates the arrival angle of radio waves from the terminal based on the phase difference between the signals received by the terminal using the antenna, and the distance estimated by the distance measurement function and the arrival estimated by the distance measurement function Estimated position information indicating the estimated position of the terminal by angle is obtained, and at least one of the plurality of fixed devices determines the terminal according to the distance estimated by the ranging function and the arrival angle estimated by the angle measurement function. An estimated position estimating unit combines the estimated position information of a plurality of fixed units arranged at different positions, and calculates the estimated positions indicated by the combined estimated position information. are obtained, and the estimated position information of the combination that minimizes the obtained distance is obtained.

According to the present disclosure, even if there is an error in the phase difference between the signals received by the multiple antennas of the fixed device and the incoming waves from the terminal, the position of the terminal can be estimated with high accuracy.

1 is a configuration diagram showing a radio communication system equipped with a terminal position estimation device according to Embodiment 1; FIG. 2 is a block diagram showing the configuration of a transmitting/receiving section in the terminal position estimation device according to Embodiment 1; FIG. 2 is a schematic block diagram showing the configuration of a fixed device and a terminal position estimation section in the terminal position estimation device according to Embodiment 1; FIG. FIG. 4 is a diagram showing optical path length differences of radio waves received by a first antenna and a second antenna; A diagram showing the relationship between the phase difference P and the arrival angle θ in radio waves received by the first antenna and the second antenna when the arrangement interval between the first antenna and the second antenna is λ/2. is. In the terminal position estimation apparatus according to Embodiment 1, the arrangement interval between the first antenna and the second antenna is λ/2, and reception by the first antenna and the second antenna when an error factor occurs FIG. 2 is a diagram illustrating an example of the relationship between the phase difference P and the arrival angle θ in radio waves transmitted. In the terminal position estimation apparatus according to Embodiment 1, the arrangement interval between the first antenna and the second antenna is λ/2, and reception by the first antenna and the second antenna when an error factor occurs FIG. 10 is a diagram illustrating another example of the relationship between the phase difference P and the arrival angle θ in the radio wave that is transmitted. 4 is a flowchart showing operations in the terminal position estimation device according to Embodiment 1; FIG. 9 is a block diagram showing the configuration of a transmitting/receiving section in the terminal position estimation device according to Embodiment 2; In the terminal position estimation apparatus according to Embodiment 2, the arrangement interval between the first antenna and the second antenna is λ/2, and reception by the first antenna and the second antenna when an error factor occurs FIG. 2 is a diagram illustrating an example of the relationship between the phase difference P and the arrival angle θ in radio waves transmitted. FIG. 10 is a block diagram showing the configuration of a transmitting/receiving section in the terminal position estimation device according to Embodiment 3; In the terminal position estimation apparatus according to Embodiment 3, in the relationship between the phase difference P and the arrival angle θ between the radio waves received by the first antenna and the second antenna, the phase difference P exceeds +180° or −180° 10 is a diagram illustrating an example of the relationship between the phase difference P and the arrival angle θ, in which a plurality of arrival angles θ corresponding to the phase difference P exist at any phase difference P when the angle is less than °. FIG. 11 is a block diagram showing the configuration of a transmitting/receiving section in a terminal position estimation device according to Embodiment 4; In the terminal position estimation apparatus according to Embodiment 4, in the relationship between the phase difference P and the arrival angle θ between the radio waves received by the first antenna and the second antenna, the phase difference P exceeds +180° or −180° When the angle of arrival θ corresponding to the phase difference P is plural, an example of the relationship between the phase difference P and the angle of arrival θ when an error factor occurs will be explained. It is a figure to do. FIG. 12 is a configuration diagram showing a radio communication system including a terminal position estimation device according to Embodiment 5; FIG. 13 is a block diagram showing the configuration of a transmitting/receiving section in a terminal position estimation device according to Embodiment 5; FIG. 11 is a configuration diagram showing a vehicle radio communication system including a vehicle radio device according to Embodiment 6; FIG. 12 is a schematic block diagram showing the configuration of a fixed device and a terminal position estimation unit in a vehicle radio device according to Embodiment 6;

Embodiment 1.
A terminal position estimation device 1 according to Embodiment 1 will be described with reference to FIGS. 1 to 8. FIG.
A radio communication system includes a terminal position estimation device 1 and a terminal 20 .
The terminal position estimation device 1 includes a plurality of fixed terminals, in this example, a first fixed terminal 10A and a second fixed terminal 10B, and a terminal position estimation section 30. FIG.
A terminal 20 includes an antenna 21 and a transmitting/receiving section 22 .
Each of the first fixed device 10A and the second fixed device 10B and the terminal 20 perform wireless communication.

Although the fixed machines are the first fixed machine 10A and the second fixed machine 10B, the number of the fixed machines is not limited to two, and a plurality of three or more may be used. Even if there are three or more fixed units, each fixed unit has the same configuration and performs the same operation.
In order to avoid complication, the first fixed machine 10A and the second fixed machine 10B will be explained as the fixed machine 10 unless they need to be explained individually.

When the radio communication system of the present disclosure is used as a mobile communication system, the plurality of fixed devices 10 are base stations and the terminals 20 are mobile communication terminals.
Further, when the application of the wireless communication system of the present disclosure is a keyless system for a vehicle such as an automobile, the plurality of fixed devices 10 are communication devices mounted on the vehicle, and the terminal 20 is a keyless portable device of the keyless system.

A mobile communication terminal or a keyless portable device of a keyless system as the terminal 20 is generally known, and a detailed description thereof will be omitted assuming that the terminal 20 simply includes an antenna 21 and a transmitting/receiving section 22 .
The number of antennas 21 is not limited to one, and may be plural.
Hereinafter, the fixed device 10 and the terminal 20 will simply be described.

Each of the plurality of fixed devices 10 has a ranging function for estimating the distance to the terminal 20, and an angle measuring function for estimating the direction to the terminal 20, that is, the arrival angle of the radio waves from the terminal 20, multiple times within a set measurement time. and obtain a plurality of estimated position information indicating the estimated position of the terminal 20 according to the estimated distance and the plurality of estimated arrival angles. A plurality of pieces of estimated position information are output to terminal position estimating section 30 .
A plurality of fixed machines 10 are arranged at different positions.

Note that not all of the plurality of fixed devices 10 output multiple pieces of estimated position information. be.
However, when at least one fixed device 10 out of the plurality of fixed devices 10 outputs a plurality of pieces of estimated position information, the terminal position estimation device 1 according to Embodiment 1 functions effectively.
In the following description, in order to avoid complication, it is assumed that all of the plurality of stationary devices 10 output a plurality of pieces of estimated position information.

Each fixed unit 10 comprises a plurality of antennas, in this example the first

fixed unit

10A, 10B comprises

first antennas

11A, 11B and

second antennas

12A, 12B and

transceivers

13A, 13B.
Although two antennas, ie, the

first antennas

11A, 11B and the

second antennas

12A, 12B are provided for each of the first

stationary devices

10A, 10B, the number of antennas may be three or more. That is, the number of antennas should be plural.
Hereinafter, in order to avoid complication, the first fixed device 10A and the second fixed device 10B will be explained as the first antenna 11, the second antenna 12, and the transmitting/receiving section 13, unless it is necessary to explain them individually. do.

Although the first antenna 11 and the second antenna 12 are used as transmitting/receiving antennas in this example, the first antenna 11 may be used as a transmitting/receiving antenna, and the second antenna 12 may be used as a receiving antenna. And the second antenna 12 may be used as a receiving antenna, and a transmitting antenna may be arranged in addition.

The first antenna 11 radiates radio waves into space, receives the radio waves from the space as incoming waves, and outputs a received signal based on the incoming waves.
The second antenna 12 receives radio waves from space as incoming waves and outputs reception signals based on the incoming waves.

As shown in FIG. 2, the transmitting/receiving unit 13 processes and estimates a transmission signal processing unit 131 that outputs a transmission signal to the first antenna 11, and the reception signals from the first antenna 11 and the second antenna 12. It has a received signal processing unit 132 that outputs position information.

The received signal processing unit 132 of the transmission/reception unit 13 has a distance measurement function unit 1321 , an angle measurement function unit 1322 and an estimated position output unit 1323 .
The distance measurement function unit 1321, the angle measurement function unit 1322, and the estimated position output unit 1323 are configured by a CPU (Central Processing Unit), a RAM (Random Access Memory), and a ROM (Read only memory), and are stored in the ROM. The following processes are executed by loading the program into the RAM and executing various processes based on the program loaded into the RAM by the CPU. The angle measurement function unit 1322, the angle measurement function unit 1322, and the estimated position output unit 1323 are driven by a general-purpose OS (Operating System).

The ranging function unit 1321 receives the transmission signal output to the first antenna 11 and the reception signal output from the first antenna 11 that received the return wave radiated from the antenna 21 of the terminal 20, and receives the input signal. The distance to the terminal 20 is estimated from the transmitted signal and the received signal.

The angle measurement function unit 1322 receives the reception signal output from the first antenna 11 and the second antenna 12 that received the return wave radiated from the antenna 21 of the terminal 20, and receives the received signal from the input first antenna 11. and the received signal output from the second antenna 12, the arrival angle of the return wave radiated from the antenna 21 of the terminal 20 is estimated multiple times within the set measurement time.

Estimated position output section 1323 outputs a plurality of estimated position information indicating the estimated position of the terminal based on each of the estimated distance information obtained by ranging function section 1321 and the plurality of estimated arrival angle information obtained by angle measurement function section 1322. Output to terminal position estimation section 30 .
The estimated position information is information indicating an estimated position obtained by converting a pair of a distance based on the estimated distance information and an arrival angle based on the estimated arrival angle information into spatial coordinates.
The estimated position information is three-dimensional coordinate information. It is represented by the x-, y-, and z-coordinates on the axes.

The distance measurement function section 1321 of the received signal processing section 132 operates as follows to estimate the distance to the terminal 20 .
The distance measurement function unit 1321 estimates the distance to the terminal 20 using a method using the propagation time of communication.

Based on the transmission signal output from the transmission signal processing unit 131 of the transmission/reception unit 13, the first antenna 11 radiates transmission waves composed of radio waves toward space.
A transmission wave radiated from the first antenna 11 is received by the antenna 21 of the terminal 20 and input to the transmitting/receiving section 22 of the terminal 20 as a received signal.
The transmitting/receiving unit 22 of the terminal 20 outputs a reply signal for replying to the antenna 21 based on the input received signal, and the reply wave in the form of radio waves is radiated from the antenna 21 toward space.

The first antenna 11 and the second antenna 12 of the fixed device 10 receive the return wave from the antenna 21 of the terminal 20 as an incoming wave, and output the received signal to the received signal processing section 132 of the transmitting/receiving section 13 as a received signal.
From the time when the transmission signal processing unit 131 outputs the transmission signal to the first antenna 11, the ranging function unit 1321 of the reception signal processing unit 132 receives the return wave from the terminal 20 and transmits the reception signal to the first antenna 11. The time until the output to the received signal processing unit 132 is measured.

The distance measurement function unit 1321 obtains the round trip propagation time by subtracting the time required for signal processing by the transmitter/receiver 13 and the time required for signal processing by the transmitter/receiver 22 of the terminal 20 from the measured time.
The distance measurement function unit 1321 obtains estimated distance information indicating the estimated distance from the fixed device 10 to the terminal 20 by setting the one-way propagation time to 1/2 of the round-trip propagation time and multiplying the one-way propagation time by the speed of light. obtain.

The angle measurement function unit 1322 of the received signal processing unit 132 receives the return wave from the antenna 21 of the terminal 20 as an incoming wave, and receives the received signal from the first antenna 11 of the fixed device 10 and the received signal from the second antenna 12. The direction of the terminal 20, that is, the arrival angle is estimated from the phase difference P between the terminal 20 and the signal, and estimated arrival angle information indicating the estimated arrival angle of the arrival wave from the antenna 21 of the terminal 20 is obtained.
The angle measurement function unit 1322 obtains the estimated arrival angle information of the incoming wave multiple times within the set measurement time.

Now, as shown in FIG. 4, the arrangement interval between the first antenna 11 and the second antenna 12 is d. It is assumed that the first antenna 11 and the second antenna 12 are arranged on a straight line along the x-axis (x-direction).
A plane wave, which is a return wave from the antenna 21 of the terminal 20, is transmitted to the first antenna 11 and the second antenna 12 as an incoming wave at an angle θ between the y-axis (y direction, vertical direction) perpendicular to the x-axis. and arrived.

At this time, the optical path length difference D between the optical path from the terminal 20 to the first antenna 11 and the optical path from the terminal 20 to the second antenna 12 is given by the following equation (1).
D=d sin θ (1)

The phase difference P between the incoming wave received by the first antenna 11 and the incoming wave received by the second antenna 12 is expressed by the following equation (2).
P=k*D=k*d sin θ (2)
k is a wave number and can be expressed by the following equation (3).
k=2π/λ (3)
λ is the wavelength of the radio wave that is the return wave from the antenna 21, and is expressed by the following equation (4).
λ=C/f (4)
However, C is the speed of light and f is the frequency.

The phase difference P is obtained by the following equation (5) by substituting the above equation (4) into the above equation (3) and then into the above equation (2).
P=k d sin θ=(2π/λ) d sin θ=(2 π/(C/f)) d sin θ
=(2πf/C)·d sin θ (5)

Since the speed of light C and the frequency f are known, and the phase difference P is a value set by the arrangement interval d, the arrival angle θ of the return waves from the first antenna 11 and the second antenna 12 is the phase difference P. By knowing, it can be obtained by the above equation (5).

In FIG. 4, the optical path difference and the phase difference P are the same even when the incoming waves are rotated around the arrangement direction of the first antenna 11 and the second antenna 12, that is, the x-axis.
Here, for the sake of simplicity, it is assumed that the arrangement direction of the first antenna 11 and the second antenna 12 and the direction of incoming waves are on the xy plane.

Also, when the arrangement direction of the first antenna 11 and the second antenna 12 and the direction of the incoming wave are on the xy plane, the arrival angle of the incoming wave is θ and (180°−θ ), the optical path length difference and the phase difference P are the same.
Due to the directivity of the first antenna 11 and the second antenna 12, if the radio wave from the -y direction, that is, the direction of the incoming wave is (180°-θ) is not received, there is only one direction of the incoming wave. Determined by

If the arrangement interval d between the first antenna 11 and the second antenna 12 is λ/2, the relationship between the phase difference P and the arrival angle θ according to the above equation (5) is uniquely determined as shown in FIG. .
FIG. 5 shows that the arrival angle θ on the horizontal axis is uniquely determined from the phase difference P on the vertical axis.
Therefore, the angle measurement function unit 1322 of the received signal processing unit 132 receives the received signal from each of the first antenna 11 and the second antenna 12 of the fixed device 10 which received the return wave from the antenna 21 of the terminal 20 as an incoming wave. The arrival angle θ of the incoming wave from the antenna 21 can be obtained by obtaining the phase difference P at .

As described above, the distance to the terminal is obtained by the distance measurement function unit 1321, and the arrival angle of the arrival wave from the terminal 20 is obtained by the angle measurement function unit 1322. FIG.
As a result, the estimated position output unit 1323 uses the estimated distance information obtained by the distance measurement function unit 1321 and the estimated angle of arrival information obtained by the angle measurement function unit 1322 as estimated position information indicating the estimated position of the terminal. Output to the position estimation unit 30 .

By the way, due to mutual coupling between the first antenna 11 and the second antenna 12, diffraction from the structure itself of the first antenna 11 and the second antenna 12, noise generated in the transmitting/receiving section 13, etc., reception An error may occur in the phase difference P between the signal received from the first antenna 11 and the signal received from the second antenna 12 obtained by the angle measurement function unit 1322 of the signal processing unit 132 .

In FIG. 6, the solid line T indicates the ideal relationship between the phase difference P and the arrival angle θ, and the dashed line F indicates the relationship between the phase difference P and the arrival angle θ with an error in the phase difference due to the cause described above.
A solid line T represents an ideal value obtained by the above equation (5) assuming that the phase difference P has no error, and is the same as the solid line T shown in FIG.
A dashed line F shows the relationship between the phase difference P having an error and the arrival angle θ, and assumes that +60° is added as the phase difference P error.
That is, the dashed line F indicates that the phase difference P deviates from the ideal phase difference P by +60° with respect to the arrival angle θ.
The error of +60° is an example in which a large error is given for explanation.

For example, assume that the arrival angles θ of the waves arriving at the first antenna 11 and the second antenna 12 are 0°.
In this case, according to the above equation (5), the phase difference P between the signal received from the first antenna 11 and the signal received from the second antenna 12 is ideally is 0°.

Assuming that +60° is added to the phase difference P as an error, the received signal from the first antenna 11 indicating that the arrival angle θ of the waves arriving at the first antenna 11 and the second antenna 12 is 0°. A phase difference P between the signal received from the second antenna 12 is 60° indicated by a black circle in FIG.
When the phase difference P is 60°, the angle measurement function unit 1322 sets the estimated arrival angle θ to 20° according to the above equation (5).
That is, the angle measurement function unit 1322 obtains an estimated arrival angle θ that is different from the true arrival angle θ.

Further, even when there is a time-varying error factor and the terminal 20 is not moving, every time the angle measurement function unit 1322 of the received signal processing unit 132 obtains the estimated arrival angle, the angle measurement function unit 1322 obtains the first The phase difference P between the received signal from one antenna 11 and the received signal from the second antenna 12 may be different.

Assume now that there is no error and that +60° is added as an error of the phase difference P when the arrival angles are obtained at different times.
Assuming that the arrival angle θ of the waves arriving at the first antenna 11 and the second antenna 12 is 0°, as described with reference to FIG. The phase difference P between the signal received from the first antenna 11 and the signal received from the second antenna 12 is 0°, and the arrival angle θ obtained by the above equation (5) is 0°. The estimated arrival angle θ obtained by the angle function unit 1322 matches the true arrival angle θ.

On the other hand, when +60° is added as an error of the phase difference P, the phase difference P obtained by the angle measurement function unit 1322 is 60°, and the arrival angle θ obtained by the above equation (5) is 20°. There is a difference between the estimated arrival angle θ obtained by the function unit 1322 and the true arrival angle θ.
That is, even though the terminal 20 is not moving, the estimated arrival angle θ obtained by the angle measurement function unit 1322 takes two values of 0° and 20° depending on the time.

Also, a case will be described with reference to FIG. 7 assuming that the arrival angle θ of the waves arriving at the first antenna 11 and the second antenna 12 is 60°.
In FIG. 7, the solid line T and broken line F are the same as the solid line T and broken line F shown in FIG.
In this case, according to the above equation (5), the phase difference P between the signal received from the first antenna 11 and the signal received from the second antenna 12 is ideally 155° to .

Assuming that +60° is added to the phase difference P as an error, the received signal from the first antenna 11 indicating that the arrival angle θ of the waves arriving at the first antenna 11 and the second antenna 12 is 60°. The phase difference P between the signal received from the second antenna 12 is 215° (=155+60).
Since the phase makes one round at 360°, a phase difference P exceeding +180° or below -180° cannot be distinguished from a phase difference P within ±180°. That is, adding or subtracting a value that is an integral multiple of 360° to or from the phase value is synonymous with the original phase value. In this example, a phase difference of 215° is synonymous with -145° (=215-360).
A phase difference P of −145° is indicated by a black circle in FIG.

When the phase difference P is −145°, the angle measurement function unit 1322 sets the estimated arrival angle θ to −54° according to the above equation (5).
That is, the angle measurement function unit 1322 obtains an estimated arrival angle θ that is different from the true arrival angle θ. In this case, as the sign of the phase difference P is inverted, the estimated arrival angle .theta.
Thus, even though the terminal 20 is not moving, the estimated arrival angle θ obtained by the angle measurement function unit 1322 takes two values of 60° and −54° depending on the time.

Therefore, based on the estimated distance information obtained by the distance measurement function unit 1321 and the estimated arrival angle information obtained by the angle measurement function unit 1322, the estimated position information indicating the estimated position of the terminal 20 output by the estimated position output unit 1323 is , may take different values depending on the time of day even though the terminal 20 is not moving.
Also, the position indicated by the estimated position information of the terminal 20 by the first fixed device 10A and the position indicated by the estimated position information of the terminal 20 at the same time by the second fixed device 10B may differ.

Therefore, in the terminal position estimation apparatus 1 according to Embodiment 1, the angle measurement function unit 1322 of the reception signal processing unit 132 in the transmission/reception unit 13 outputs from the input first antenna 11 within the set measurement time Based on the received signal and the received signal output from the second antenna 12, the arrival angle of the return wave radiated from the antenna 21 of the terminal 20 is estimated multiple times, at least twice.
As a result, the estimated position output section 1323 also outputs a plurality of at least two pieces of estimated position information to the terminal position estimation section 30 .

An error factor occurs in each of the first fixed device 10A and the second fixed device 10B, and two pieces of estimated position information indicating different positions are output from the estimated position output unit 1323 in the first fixed device 10A. The estimated position output unit 1323 of the fixed device 10B outputs two pieces of estimated position information indicating a position different from the estimated position information output from the first fixed device 10A, and the two estimated position information indicating different positions are sent to the terminal position estimation unit 30. The case of outputting to .

In addition, when there is no error factor in both the first fixed device 10A and the second fixed device 10B and no error occurs in the phase difference P, the estimated position information output from the first fixed device 10A indicates The position matches the estimated position indicated by the estimated position information output from the second stationary device 10B.
Also, for the sake of simplification of explanation, a case where two fixed devices 10 and two pieces of estimated position information output from each fixed device 10 are obtained will be described. A case where three or more pieces of estimated position information output from the fixed device 10 are obtained can also be considered in the same way.

FIG. 1 shows an example of an estimated position based on the estimated position information when two fixed devices 10 are used and two pieces of estimated position information output from each fixed device 10 are obtained within the set measurement time.
In FIG. 1, PA1 and PA2 indicate the estimated positions obtained by the received signal processing unit 132 of the transmitting/receiving unit 13A in the first fixed device 10A, and PB1 and PB2 indicate the received signal processing of the transmitting/receiving unit 13B in the second fixed device 10B. The estimated position obtained by unit 132 is shown.

The terminal position estimating unit 30 receives estimated position information indicating a plurality of estimated positions obtained by the received signal processing unit 132 of the transmitting/receiving unit 13A in the first fixed device 10A, in this example, estimated position information indicating the estimated position PA1, and estimates Estimated position information indicating position PA2, a plurality of pieces of estimated position information obtained by received signal processing unit 132 of transmitting/receiving unit 13B in second fixed device 10B, in this example, estimated position information indicating estimated position PB1 and estimated position PB2 and the estimated position information indicating the combination that minimizes the distance between the estimated positions based on each estimated position information in the first fixed device 10A and each estimated position information in the second fixed device 10B. The estimated position information is output to the display device 40 .

That is, in this example, the distance d11 between the estimated positions PA1 and PB1, the distance d12 between the estimated positions PA1 and PB2, the distance d21 between the estimated positions PA2 and PB1, and the estimated positions PA2 and the estimated position PB2 is calculated, and the combination of the estimated positions showing the minimum distance d21, that is, the combination of the estimated position PA2 and the estimated position PB1, is selected as a set of probable positions for the terminal 20. FIG.

As a result, in the first fixed device 10A, the estimated position information indicating the estimated position is more likely to indicate the estimated position PA2 than the estimated position information indicating the estimated position PA1. As for the estimated position information indicating the position, it can be determined that the estimated position information indicating the estimated position PB1 is more likely than the estimated position information indicating the estimated position PB2.

Accordingly, in each stationary device 10, the display 40 displays more probable estimated position information selected from a plurality of output estimated position information.
In particular, as described above, even if the phase difference P exceeds +180° or falls below -180° and the phase difference is folded back, the estimated position information indicating a plurality of estimated positions indicates a likely position. can be determined.

Although the terminal position estimation unit 30 selects a combination indicating a probable position and outputs the estimated position information of the combination to the display device 40, the estimated position information of the combination indicating the selected probable position Estimated position information indicating an intermediate position may be output to the display 40 .
In addition, the terminal position estimating unit 30 outputs to the display unit 40 the estimated position information of the shortest distance indicated by the estimated distance information obtained by the distance measuring function unit 1321 among the estimated position information of the combination indicating the probable position. It may be assumed that

Further, the terminal position estimating section 30 may output to the display 40 the estimated position information with the higher power of the received signal among the combinations of estimated position information indicating the probable position.
In short, the terminal position estimation unit 30 outputs the estimated position information of the combination indicating the probable position, or selects one of the estimated positions based on the selection criteria for the estimated position information of the combination indicating the probable position. Information is output to the display 40 .

The terminal position estimation unit 30 includes an input interface 31, a storage unit 32, a two-point distance calculation unit 33, a selection unit 34, and an output interface 35, as shown in FIG.
The terminal position estimation unit 30 is composed of a CPU, a RAM, and a ROM. A program stored in the ROM is loaded into the RAM, and the CPU executes various processes based on the program loaded into the RAM. The processing shown is executed. The terminal position estimation unit 30 is driven by a general-purpose OS.

The input interface 31 receives a plurality of estimated position information indicating the estimated position of the terminal 20 from the first fixed device 10A and a plurality of estimated position information indicating the estimated position of the terminal 20 from the second fixed device 10B, A plurality of pieces of estimated position information output from the first fixed device 10A and the first fixed device 10A are linked and output to the storage unit 32, and output from the second fixed device 10B and the second fixed device 10B. A plurality of pieces of estimated position information obtained are linked and output to the storage unit 32 .

The storage unit 32 stores a plurality of pieces of estimated position information linked to the first fixed device 10A and a plurality of pieces of estimated position information linked to the second fixed device 10B.
The two-point distance calculation unit 33 reads from the storage unit 32 a plurality of estimated position information linked to the first fixed device 10A and a plurality of estimated position information linked to the second fixed device 10B. A plurality of estimated position information linked to one fixed device 10A and a plurality of estimated position information linked to a second fixed device 10B are combined with each other, and the distance between the estimated positions indicated by the combined estimated position information is linked to the estimated position information from the first fixed device 10A and the estimated position information from the first fixed device 10A, and output to the storage unit 32 as combined estimated position information.

That is, the two-point distance calculation unit 33 selects one piece of estimated position information from a plurality of pieces of estimated position information linked to the first fixed device 10A, and combines the selected estimated position information with the second fixed device 10B. The distance to each of the linked estimated position information is obtained, and the obtained distance and the estimated position information of the first stationary device 10A and the estimated position information of the second stationary device 10B are linked. The information is stored in the storage unit 32 as combined estimated position information.

Similarly, the two-point distance calculation unit 33 also links the remaining estimated position information of the plurality of pieces of estimated position information linked to the first fixed device 10A one by one to the second fixed device 10B. The distance to each of the plurality of estimated position information attached is obtained, and the obtained distance and the estimated position information of the first fixed device 10A and the estimated position information of the second fixed device 10B are linked and combined. Stored in the storage unit 32 as estimated position information.

For example, in the example shown in FIG. 1, the two-point distance calculation unit 33 calculates the distance d11 between the estimated position PA1 and the estimated position PB1, and indicates the distance d11 and the estimated position PA1 in the first stationary device 10A. The estimated position information and the estimated position information indicating the estimated position PB1 in the second stationary device 10B are linked and stored in the storage unit 32 as combined estimated position information (PA1-PB1-d11).

Similarly, the distance calculation unit 33 calculates the combined estimated position information (PA1-PB2-d12) for the distance d12 between the estimated positions PA1 and PB2, and the distance d21 between the estimated positions PA2 and PB1. The combined estimated position information (PA2-PB1-d21) and the combined estimated position information (PA2-PB2-d22) for the distance d22 between the estimated positions PA2 and PB2 are stored in the storage unit 32. FIG.

The selection unit 34 reads a plurality of combined estimated position information stored in the storage unit 32, obtains the combined estimated position information that minimizes the distance information in the combined estimated position information, and selects the first combined estimated position information based on the minimum combined estimated position information. combined estimated position information including the estimated position information from the first fixed device 10A, the estimated position information from the second fixed device 10B, and the distance information therebetween is output to the display device 40 via the output interface 35. FIG.

For example, in the example shown in FIG. 1, the selection unit 34 determines that the distance information in the combined estimated position information read from the storage unit 32 is distance d11, distance d12, distance d21, and distance d22, and the minimum distance is d21, the combined estimated position information (PA2-PB1-d21) for the distance d21 is selected, and the estimated position information indicating the estimated position PA2 by the first fixed device 10A and the estimated position PB1 by the second fixed device 10B are The combined estimated position information (PA2-PB1-d21) including the estimated position information indicating the distance d21 and the distance information indicating the distance d21 is output to the display 40 via the output interface .

At this time, the selection unit 34 displays the estimated position information indicating the intermediate estimated position PAB, which is an intermediate value between the estimated position PA2 and the estimated position PB1, instead of the combined estimated position information (PA2-PB1-d21) on the display 40. may be output to
In addition, instead of the combined estimated position information (PA2-PB1-d21), the selection unit 34 selects the estimated position information indicating the estimated position PA2 by the first fixed device 10A or the second Either one of the estimated position information indicating the estimated position PB1 by the fixed device 10B may be selected and the selected estimated position information may be output to the display device 40. FIG.

Next, the operation of the terminal position estimation device 1 according to Embodiment 1 will be explained using the flowchart shown in FIG.
In order to avoid complication of explanation, the plurality of fixed devices 10 are defined as a first fixed device 10A and a second fixed device 10B, and in each fixed device 10, the plurality of antennas are a first antenna 11 and a second antenna 12. , and the relationship shown in FIG. 1 is assumed.

Step ST1 is a step of emitting transmission waves.
In step ST1, each fixed device 10 receives a transmission signal from the transmission signal processing section 131 of the transmission/reception section 13, and radiates a transmission wave composed of radio waves into space from the first antenna 11. FIG.
A transmission wave radiated from the first antenna 11 is received by the antenna 21 of the terminal 20 and input to the transmitting/receiving section 22 of the terminal 20 as a received signal.

The terminal 20 radiates a return wave composed of radio waves into space from the antenna 21 that receives the return signal from the transmitting/receiving section 22 .
Step ST2 is a step of receiving a reply wave from the terminal 20 as an incoming wave.
In step ST2, the first antenna 11 and the second antenna 12 of each fixed device 10 receive the return wave from the antenna 21 of the terminal 20 as an incoming wave, and send it to the received signal processing unit 132 of the transmitting/receiving unit 13 as a received signal. Output.

Step ST3 is a ranging step for estimating the distance from each fixed device 10 to the terminal 20. FIG.
In step ST3, the distance measuring function unit 1321 of the reception signal processing unit 132 in each fixed device 10 detects that the first antenna 11 is transmitted from the terminal 20 from the time when the transmission signal processing unit 131 outputs the transmission signal to the first antenna 11. is received, the time until the time when the received signal is output to the received signal processing unit 132 is measured, the distance from each fixed device 10 to the terminal 20 is estimated, and estimated distance information indicating the estimated distance is obtained.

Step ST4 is an angle measurement step for estimating a plurality of arrival angles of return waves from the terminal 20. FIG.
In step ST4, the angle measurement function unit 1322 of the reception signal processing unit 132 in each fixed device 10 receives the return wave from the antenna 21 of the terminal 20, and from the first antenna 11 and the second antenna 12 of the fixed device 10 The arrival angle of the arrival wave from the antenna 21 of the terminal 20 is estimated from the phase difference P between the received signal of the terminal 20 and the estimated arrival angle information indicating the estimated arrival angle is obtained.

The angle measurement function unit 1322 obtains the phase difference P between the signal received from the first antenna 11 and the signal received from the second antenna 12, and from the obtained phase difference P, by the above equation (5), Obtain the arrival angle θ.
The angle measurement function unit 1322 obtains a plurality of pieces of estimated arrival angle information of waves arriving from the antenna 21 within the set measurement time.

Step ST5 is a position estimation step of obtaining the estimated position of the terminal 20 .
In step ST5, the estimated position output section 1323 of the received signal processing section 132 in each fixed device 10 outputs the estimated position of the terminal 20 based on each of the estimated distance information obtained in step ST2 and the plurality of arrival angle information obtained in step ST3. Obtain a plurality of estimated location information indicative of .

In this example, the estimated position information obtained by the first stationary device 10A is the estimated position information indicating the estimated position PA1 and the estimated position information indicating the estimated position PA2.
In this example, the estimated position information obtained by the second stationary device 10B is the estimated position information indicating the estimated position PB1 and the estimated position information indicating the estimated position PB2.
The processing from step ST3 to step ST5 is stored in the ROM constituting the received signal processing section 132 as a program having each step as a procedure.

The storage unit 32 in the terminal position estimation unit 30 stores a plurality of pieces of estimated position information from the plurality of fixed devices 10 via the input interface 31 in association with each fixed device 10 .
Step ST6 is a combining step of combining estimated position information from a plurality of stationary devices 10 .
In step ST6, the two-point distance calculator 33 in the terminal position estimator 30 calculates a plurality of pieces of estimated position information linked to the first fixed device 10A and the second fixed device 10B stored in the storage unit 32. are combined with each other, and the distance between the estimated positions indicated by the combined estimated position information is calculated.
The two-point distance calculation unit 33 associates the calculated result with the estimated position information from the first fixed device 10A and the estimated position information from the second fixed device 10B, and stores the result in the storage unit 32 as combined estimated position information. Output.

The distance calculation unit 33 calculates the combined estimated position information (PA1-PB1-d11) for the distance d11 between the estimated position PA1 and the estimated position PB1, and the combined estimated position for the distance d12 between the estimated position PA1 and the estimated position PB2. information (PA1-PB2-d12), combined estimated position information (PA2-PB1-d21) for distance d21 between estimated position PA2 and estimated position PB1, and combined for distance d22 between estimated position PA2 and estimated position PB2 Obtain estimated location information (PA2-PB2-d22).

Step ST7 is a selection step for obtaining an optimum combination of estimated position information.
In step ST7, the selection section 34 in the terminal position estimation section 30 obtains the combined estimated position information that minimizes the distance information among the plurality of combined estimated position information stored in the storage section 32 .
The selection unit 34 obtains, for example, the combined estimated position information (PA2-PB1-d21) for the smallest d21.
Steps ST6 and ST7 constitute a combined position estimation step of combining estimated position information from a plurality of stationary devices 10 and obtaining an optimum combined estimated position.

Step ST8 is a step of outputting the estimated position of the optimum combination.
In step ST<b>8 , the selection unit 34 outputs the estimated position information based on the obtained minimum combined estimated position information to the display device 40 via the output interface 35 .
The estimated position information output from the selection unit 34 is, for example, the estimated position information indicating the estimated position PA2 by the first fixed device 10A, the estimated position information indicating the estimated position PB1 by the second fixed device 10B, and the position information between them. Estimated position information in combination including distance information, estimated position information indicating an intermediate estimated position PAB that is an intermediate value between estimated position PA2 and estimated position PB1, or estimated position by first fixed device 10A based on selection criteria This is the estimated position information obtained by selecting either the estimated position information indicating PA2 or the estimated position information indicating the estimated position PB1 by the second fixed device 10B.

In addition, in the terminal position estimation device 1 according to Embodiment 1 described above, an error factor occurs in each of the first fixed device 10A and the second fixed device 10B, and the estimated position output unit 1323 in the first fixed device 10A Two pieces of estimated position information, ie, the estimated position information indicating the estimated position PA1 and the estimated position information indicating the estimated position PA2, which indicate different positions, are output from the estimated position output unit 1323 in the second stationary device 10B, and the estimated position output unit 1323 in the second fixed device 10B outputs the first Two estimated position information, ie, the estimated position information indicating the estimated position PB1 and the estimated position information indicating the estimated position PB2, which indicate a position different from the estimated position information output from the fixed device 10A and indicate different positions from each other. The description has been made on the assumption that the information is output to the terminal position estimation unit 30 .

However, the present invention is not limited to the above example, and an error factor occurs in the first fixed device 10A, and an estimated position PA1 indicating a different position from the estimated position output unit 1323 in the first fixed device 10A Although two different pieces of estimated position information are output, the position information and the estimated position information indicating the estimated position PA2 are output. As a result, two different pieces of estimated position information are not output, and the estimated position information indicating only one estimated position PB is output to the terminal position estimation unit 30. The terminal position estimation device 1 according to functions effectively.

That is, in this example, the terminal position estimating unit 30 uses the estimated position information indicating the estimated position PA1 and the estimated position information indicating the estimated position PA2 obtained by the received signal processing unit 132 of the transmitting/receiving unit 13A in the first stationary device 10A. , and the estimated position information indicating the estimated position PB obtained by the received signal processing unit 132 of the transmitting/receiving unit 13B in the second fixed device 10B, the distance between the estimated position PA1 and the estimated position PB, the estimated position PA2 and the estimated position The distance between the PBs is calculated, the combination of estimated positions showing the minimum distance is selected as the set showing the probable position with respect to the terminal 20 , and the estimated position information of the selected combination is output to the display 40 .

As described above, in the terminal position estimation apparatus 1 according to Embodiment 1, in a plurality of fixed stations 10 arranged at mutually different positions, at least one of the plurality of fixed stations estimates A plurality of different estimated position information indicating the estimated position of the terminal according to each of a plurality of distances and estimated arrival angles are obtained, and the estimated position information of the plurality of fixed units 10 arranged at different positions are combined with each other, and the combined estimation is performed. Since the position of the terminal 20 is estimated by obtaining the distance between the estimated positions indicated by the position information and obtaining the estimated position information of the combination that minimizes the obtained distance, for example, the plurality of antennas of the fixed device 10 Even if there is an error in the phase difference P of the received signal due to the incoming wave from the terminal 20 received by the

terminals

11 and 12, the position of the terminal 20 can be estimated with high accuracy.

Embodiment 2.
A terminal position estimation device 1 according to Embodiment 2 will be described with reference to FIGS. 9 and 10. FIG.
The terminal position estimating device 1 according to Embodiment 2 differs from the terminal position estimating device 1 according to Embodiment 1 in that angle measurement function section 1322 in at least one fixed device 10 among a plurality of fixed devices 10 is positioned. The difference is the function of changing the phase difference, that is, the addition of a phase difference changing section 1322a as shown in FIG. 9, and the other points are the same.

That is, in the terminal position estimation device 1 according to Embodiment 1, assuming that the plurality of fixed devices 10 are the first fixed device 10A and the second fixed device 10B, the first fixed device 10A with a phase difference changing unit 1322a added to the angle measurement function unit 1322. FIG.
The second fixed device 10B is the same as the second fixed device 10B in the terminal position estimation device 1 according to the first embodiment.

Further, in the first fixed device 10A, the transmitting/receiving unit 13A other than the angle measurement function unit 1322, that is, the transmission signal processing unit 131, the distance measurement function unit 1321, and the estimated position output unit 1323 are the terminal position according to the first embodiment. This is the same as the transmission signal processing unit 131, the distance measurement function unit 1321, and the estimated position output unit 1323 in the estimation device 1.
Therefore, the angle measurement function unit 1322 of the transmission/reception unit 13A in the first stationary device 10A will be mainly described below.
9 and 10, the same reference numerals as in FIGS. 1 to 8 indicate the same or corresponding parts.

In the first fixed device 10A, the angle measurement function unit 1322 of the reception signal processing unit 132 in the transmission/reception unit 13A receives the return wave from the antenna 21 of the terminal 20 as an incoming wave and The phase difference P with respect to the received signal from the second antenna 12A is obtained, the arrival angle is estimated from the obtained phase difference P, and the estimated arrival angle information of the arrival wave from the antenna 21 of the terminal 20 is obtained.

The angle measurement function unit 1322 calculates the phase difference value within a predetermined phase difference change range for the obtained phase difference P between the received signal from the first antenna 11A and the received signal from the second antenna 12A. In other words, the phase difference change amount is provided when the phase difference exceeds +180° or falls below −180° in the phase difference change range. is obtained as additional estimated arrival angle information.

Estimated position output section 1323 outputs the estimated position indicating the estimated position of terminal 20 based on the estimated distance information obtained by ranging function section 1321 for the additional estimated arrival angle information obtained by angle measurement function section 1322 as well. Information is obtained and output to the terminal position estimation unit 30 .

Next, the operation of the angle measurement function unit 1322 will be described using an example.
Assume now that the arrival angle θ of the incoming waves to the first antenna 11A and the second antenna 12A is 60°.
In this case, according to the above equation (5), the phase difference P between the signal received from the first antenna 11A and the signal received from the second antenna 12A is ideal as indicated by the asterisks in FIG. +155° to .

In addition to the error factor for the phase difference P described above, the phase difference P between the received signal from the first antenna 11A and the received signal from the second antenna 12A obtained by the angle measurement function unit 1322 is -175°. Suppose it was In FIG. 10, the black circle indicates the position where the phase difference P is -175°.
When the phase difference P is −175°, the angle measurement function unit 1322 sets the estimated arrival angle θ to −77° according to the above equation (5).
In other words, the phase difference P of −175° is a value obtained by folding back the ideal phase difference of +155° by +180°. Due to this occurrence, the angle measurement function unit 1322 obtains an estimated arrival angle θ that is different from the true arrival angle θ.

In this way, when the phase difference P is folded back, it is assumed that an error is added to the obtained phase difference P, and the value of the phase difference is changed within a range that can be taken as the original phase difference P. .
The phase difference is changed by changing the value of the phase difference within a predetermined phase difference change range by the phase difference changer 1322a in the angle measurement function unit 1322 .
For the phase difference change range, the variation value is obtained from the stability of the phase detection of the angle measurement function unit 1322 in the first stationary device 10A, or the terminal position estimation device 1 according to Embodiment 2 is used in the usage environment, and an experiment is performed. set by defining

In Embodiment 2, the phase difference change range is set to ±45°.
Therefore, when the phase difference P obtained by the angle measurement function unit 1322 is −175°, the phase difference performed by the phase difference change unit 1322a is −130° (=−175°+45°) to −180°. The range is from +180° to +140° (=-175°-45°).
In this case, folding does not occur in the range from -130° to -180°. The range from +180° to +140° corresponds to after folding.

Therefore, after folding, the smallest change in phase difference is +180°.
In other words, when the phase difference exceeds +180° or falls below -180° in the phase difference change range, the phase difference P after the phase difference change is +180° when the amount of change in the phase difference is the smallest.
This is indicated by white circles in FIG.
Therefore, the phase difference changer 1322a adds +180° as the phase difference P.

When the phase difference P added by the phase difference changing unit 1322a is +180°, the angle measurement function unit 1322 sets +90° as the additional estimated arrival angle θ according to the above equation (5).
In this case, the aliasing of the phase difference is eliminated, and the angle measurement function unit 1322 obtains the estimated arrival angle θ with a reduced error from the true arrival angle θ.
Although -180° and +180° are synonymous, for convenience of explanation, the case slightly larger than -180° (-179° side) is -180°, and the case slightly smaller than +180° (+179° ° side) is described as +180°.

The estimated position output unit 1323 outputs the phase difference P obtained by the angle measurement function unit 1322 of −77° corresponding to −175° and +90° corresponding to the phase difference +180° added by the phase difference changing unit 1322a. Estimated position information indicating the estimated position of the terminal is obtained from the estimated distance information obtained by the distance measurement function section 1321 using both as the estimated arrival angle θ, and is output to the terminal position estimation section 30 .
The terminal position estimating section 30 is the same as the terminal position estimating section 30 in the terminal position estimating apparatus 1 according to Embodiment 1, so the description thereof is omitted.

It should be noted that the second fixed device 10B may also have a phase difference changing section 1322a added to the angle measurement function section 1322 in the same manner as the first fixed device 10A.
In all of the plurality of fixed devices 10, a phase difference changing unit 1322a may be added to the angle measurement function unit 1322 as in the case of the first fixed device 10A.

As described above, the terminal position estimation apparatus 1 according to Embodiment 2 uses the angle measurement function of the fixed device 10 to adjust the phase difference within the phase difference change range with respect to the phase difference P of the signal received by radio waves from the terminal 20. Provided with a phase difference change function to change the value, after the phase difference change when the amount of change in the phase difference is the smallest when the phase difference exceeds +180° or falls below -180° in the phase difference change range Since the arrival angle corresponding to the phase difference is added as the estimated arrival angle, for example, an error occurs in the phase difference of the received signal due to the arrival wave from the terminal 20 received by the plurality of

antennas

11 and 12 of the fixed device 10. , the position of the terminal 20 can be estimated with higher accuracy.

Embodiment 3.
A terminal position estimation device 1 according to Embodiment 3 will be described with reference to FIGS. 11 and 12. FIG.
The terminal position estimation device 1 according to Embodiment 3 has an angle measurement function for obtaining a plurality of pieces of estimated position information for the angle measurement function unit 1322 in each fixed device 10 compared to the terminal position estimation device 1 according to Embodiment 1. That is, as shown in FIG. 11, the angle measurement function unit 1322-1 is different, and other points are the same.

At least one fixed device 10 among the plurality of fixed devices 10 may be the angle measurement function unit 1322-1, but in the following description, the plurality of fixed devices 10 are assumed to be the angle measurement function unit 1322-1. do.
11 and 12, the same reference numerals as those in FIGS. 1 to 8 indicate the same or corresponding parts.

FIG. 12 is a diagram showing the relationship between the phase difference P and the arrival angle θ.
As shown by a solid line T1 in FIG. In the relationship, when the phase difference P folds above +180° or below -180°, there are multiple angles of arrival corresponding to the phase difference P.

An example of this is an example in which the arrangement interval d between the first antenna 11 and the second antenna 12 is set to 0.75λ. λ is the wavelength of radio waves from the terminal 20 .
In this example, angle measurement function unit 1322-1 estimates a plurality of arrival angles θ in the range of phase difference P from +90° to +180° and from −90° to −180°.

In addition, the arrangement interval d between the first antenna 11 and the second antenna 12 is not limited to 0.75λ, and the arrangement interval d may be any value exceeding 1/2 of the wavelength λ of the radio wave from the terminal 20. Just do it. When the arrangement interval d is set to a value exceeding 1/2 of the wavelength λ, the phase difference P is folded back in relation to the arrival angle θ, and a plurality of arrival angles θ corresponding to the phase difference P exist.
Further, even if the arrangement interval d is 1/2 or less of λ, the phase difference P is folded back in relation to the arrival angle θ due to electromagnetic coupling or the like between the first antenna 11 and the second antenna 12. , and again there are multiple angles of arrival corresponding to the phase difference P.

Below, in the terminal position estimation apparatus 1 according to Embodiment 1, the arrangement interval d between the first antenna 11 and the second antenna 12 is 0.5λ, whereas the terminal position according to Embodiment 3 A case where the estimation device 1 has an arrangement interval d of 0.75λ will be described as an example.
Since the arrangement interval d is different from that of the terminal position estimation device 1 according to Embodiment 1, the operation of the angle measurement function unit 1322-1 in the fixed device 10 is the same as that of the angle measurement function unit in the terminal position estimation device 1 according to Embodiment 1. Although the operation is mainly different from that of 1322, other points are the same, so the angle measurement function unit 1322-1 will be mainly described.

The angle measurement function unit 1322-1 of the reception signal processing unit 132 in the transmission/reception unit 13 receives the return wave from the antenna 21 of the terminal 20 as an incoming wave, and receives the received signal from the first antenna 11 and the is obtained, and the arrival angle .theta. is estimated from the obtained phase difference P to obtain estimated arrival angle information of the arrival wave from the antenna 21 of the terminal 20. FIG.

At this time, the received signal from the first antenna 11 and the received signal from the second antenna 12 input to the angle measurement function unit 1322-1 have a phase difference P between the received signals and the arrival of the radio wave from the terminal 20. In relation to the angle θ, the phase difference P exceeds +180° or falls below −180°, and at any phase difference P there are a plurality of arrival angles θ corresponding to the phase difference P.

When the angle measurement function unit 1322-1 obtains a plurality of arrival angles θ for the phase difference P according to the above equation (5), it obtains a plurality of estimated arrival angle information corresponding to each of the plurality of arrival angles θ.
Estimated position output section 1323 outputs a plurality of estimated positions indicating the estimated position of the terminal based on the estimated distance information obtained by ranging function section 1321 for the plurality of estimated arrival angle information obtained by angle measurement function section 1322-1. Estimated position information is obtained and output to terminal position estimation section 30 .

Next, the operation of the angle measurement function unit 1322-1 will be described using an example.
Assume now that the arrival angle θ of the incoming waves to the first antenna 11 and the second antenna 12 is -30°.
In this case, according to the above equation (5), the phase difference P between the signal received from the first antenna 11 and the signal received from the second antenna 12 is ideally -135°.

Assume that the phase difference P between the signal received from the first antenna 11 and the signal received from the second antenna 12 obtained by the angle measurement function unit 1322-1 is ideally 135°.
If the phase difference P is 135°, the angle measurement function unit 1322-1 sets −30° and 57° as the estimated arrival angles θ according to the above equation (5). In FIG. 12, two estimated arrival angles θ are obtained, −30° indicated by black circles and 57° indicated by arrows.

In this way, in the relationship between the phase difference P and the arrival angle θ, if the phase difference P exceeds +180° or falls below −180°, the phase difference P changes. The change in the arrival angle θ is small, and the accuracy of angle measurement is improved.

Also, if there are a plurality of arrival angles θ corresponding to the phase difference P, the angle measurement function unit 1322-1 obtains a plurality of estimated arrival angle information corresponding to each of the plurality of arrival angles θ.
Estimated position output section 1323 then indicates the estimated position of the terminal based on the estimated distance information obtained by distance measurement function section 1321 for the plurality of pieces of estimated arrival angle information obtained by angle measurement function section 1322-1. A plurality of pieces of estimated location information are obtained and output to the terminal location estimation unit 30 .

As a result, even if there are a plurality of arrival angles θ corresponding to the phase difference P, the terminal position estimator 30 can obtain a probable estimated position of the terminal.
The terminal position estimating section 30 is the same as the terminal position estimating section 30 in the terminal position estimating apparatus 1 according to Embodiment 1, so the description thereof is omitted.

As described above, in terminal position estimation apparatus 1 according to Embodiment 3, angle measurement function section 1322-1 determines that phase difference P exceeds +180° or -180° in the relationship between phase difference P and arrival angle θ. When the reception signal from the first antenna 11 and the reception signal from the second antenna 12 are received, the arrival angle θ corresponding to the phase difference P is one. Obtaining estimated angle of arrival information with improved angle accuracy, and if there are a plurality of arrival angles θ corresponding to the phase difference P, a plurality of pieces of estimated arrival angle information corresponding to each of the plurality of arrival angles θ are obtained. It can be estimated with higher accuracy.

Embodiment 4.
A terminal position estimation device 1 according to Embodiment 4 will be described with reference to FIGS. 13 and 14. FIG.
The terminal position estimation device 1 according to Embodiment 4 differs from the terminal position estimation device 1 according to Embodiment 3 in that angle measurement function section 1322-1 in at least one fixed device 10 among the plurality of fixed devices 10 The difference is that a phase difference changing section 1322a is added as shown in FIG. 13, and other points are the same.

That is, in the terminal position estimation device 1 according to Embodiment 4, assuming that the plurality of fixed devices 10 are the first fixed device 10A and the second fixed device 10B, the first fixed device 10A with a phase difference changing unit 1322a added to the angle measurement function unit 1322-1.
The second fixed device 10B is the same as the second fixed device 10B in the terminal position estimation device 1 according to the third embodiment.
Similarly to the first fixed device 10A, the second fixed device 10B may also have the function of changing the phase difference, that is, the phase difference changing portion 1322a added to the angle measurement function section 1322-1.
13 and 14, the same reference numerals as in FIGS. 11 and 12 denote the same or corresponding parts.

FIG. 14 is a diagram showing the relationship between the phase difference P and the arrival angle θ.
As shown by a solid line T1 in FIG. In the relationship, when the phase difference P is greater than +180° or less than -180°, there are multiple arrival angles θ corresponding to the phase difference P.

A terminal position estimation apparatus 1 according to Embodiment 4 will be described with an example in which the arrangement interval d is 0.75λ.
In the first fixed device 10A, the angle measurement function unit 1322-1 of the received signal processing unit 132 in the transmitting/receiving unit 13A receives the return wave from the antenna 21 of the terminal 20 as an incoming wave. Obtain the phase difference P between the signal and the received signal from the second antenna 12A, estimate the arrival angle θ from the obtained phase difference P, and obtain the estimated arrival angle information of the arrival wave from the antenna 21 of the terminal 20. .

At this time, the received signal from the first antenna 11A and the received signal from the second antenna 12A input to the angle measurement function unit 1322-1 are the phase difference P between the received signals and the arrival of the radio wave from the terminal 20. In relation to the angle θ, if the phase difference P exceeds +180° or falls below −180°, there are a plurality of arrival angles θ corresponding to any phase difference P.

When the angle measurement function unit 1322-1 obtains a plurality of arrival angles θ for the phase difference P according to the above equation (5), it obtains a plurality of estimated arrival angle information corresponding to each of the plurality of arrival angles θ.
The angle measurement function unit 1322-1 calculates the obtained phase difference P between the received signal from the first antenna 11A and the received signal from the second antenna 12A in the relationship between the phase difference P and the arrival angle θ. On the other hand, if there is an arrival angle θ after folding, it has a phase difference changing unit 1322a that changes the value of the phase difference within a predetermined phase difference change range with respect to the obtained phase difference P. That is, the phase difference changing function and add the arrival angle corresponding to the phase difference after the phase difference change when the amount of change in the phase difference is the smallest, corresponding to the phase difference changed in the phase difference change range, and the phase difference after folding Obtained as estimated arrival angle information.

Estimated position output section 1323 outputs a plurality of estimated positions indicating the estimated position of the terminal based on the estimated distance information obtained by ranging function section 1321 for the plurality of estimated arrival angle information obtained by angle measurement function section 1322-1. In addition to obtaining the estimated position information, the estimated position of the terminal 20 is indicated by the estimated distance information obtained by the distance measurement function unit 1321 for the additional estimated arrival angle information obtained by the angle measurement function unit 1322-1. Estimated position information is obtained and output to terminal position estimation section 30 .

Next, the operation of the angle measurement function unit 1322-1 will be described using an example.
Assume now that the arrival angle θ of the incoming waves to the first antenna 11A and the second antenna 12A is 60°.
In this case, according to the above equation (5), the phase difference P between the signal received from the first antenna 11A and the signal received from the second antenna 12A is ideal as indicated by the asterisks in FIG. is -127°. A phase difference P of −127° with respect to 60° where the arrival angle θ is larger than 42° causes aliasing.
That is, the arrival angle θ of 60° is the arrival angle after folding in the relationship between the phase difference P and the arrival angle θ.

With the addition of the error factor for the phase difference P described above, the phase difference P between the signal received from the first antenna 11A and the signal received from the second antenna 12A obtained by the angle measurement function unit 1322-1 becomes - Suppose it was 80°. In FIG. 14, the positions where the phase difference P is −80° are indicated by black circles.
When the phase difference P is −80°, the angle measurement function unit 1322-1 sets the estimated arrival angle θ to −17° according to the above equation (5).

That is, the arrival angle θ of −17° for the phase difference P of −80° is the value before folding with respect to the ideal phase difference of −127° for the arrival angle θ of 60°. Due to no folding, the angle measurement function unit 1322-1 obtains an estimated arrival angle θ that is different from the true arrival angle θ.

In this way, when no folding occurs in the phase difference P obtained from the received signal from the first antenna 11A and the received signal from the second antenna 12A, an error is added to the obtained phase difference P. Assuming that the phase difference P obtained from the received signal has an arrival angle after aliasing, the value of the phase difference is changed within a range that can be taken as the original phase difference P. FIG.
The phase difference is changed by changing the value of the phase difference within a predetermined phase difference change range by the phase difference changer 1322a in the angle measurement function unit 1322 .
For the phase difference change range, the variation value is obtained from the stability of the phase detection of the angle measurement function unit 1322 in the first stationary device 10A, or the terminal position estimation device 1 according to Embodiment 4 is used in the usage environment, and an experiment is performed. set by defining

In Embodiment 4, the phase difference change range is set to ±45°.
Therefore, when the phase difference P obtained by the angle measurement function unit 1322-1 is −80°, the phase difference change range performed by the phase difference change unit 1322a is from −35° (=−80°+45°) to The range is -125° (=-80°-45°).
Folding does not occur in the range from -35° to -125°.

On the other hand, the relationship between the phase difference P and the arrival angle θ turns around after the arrival angle θ is +42°. From the obtained phase difference P, the relationship between the phase difference after folding and the angle of arrival can be obtained with the smallest amount of change in the phase difference because the amount of change in the phase difference is -10° and the phase difference P is - This is the case of 90°. This is indicated by white circles in the figure.
Therefore, the phase difference changer 1322a adds −90° as the phase difference P. FIG.
In addition to the estimated arrival angle θ of −17°, the angle measurement function unit 1322-1 calculates the value obtained by the above equation (5) for the phase difference P of −90°, and the arrival angle indicated by the arrow in FIG. θ adds +90° as the estimated arrival angle θ.

The added arrival angle θ of +90° uses the relationship between the phase difference P after folding and the arrival angle θ, and the estimated arrival angle θ corresponding to the obtained phase difference P of −80° is −17°. Therefore, the arrival angle θ is obtained with a reduced error between the true arrival angle θ and 60°.

The estimated position output unit 1323 corresponds to −17° corresponding to −80° for the phase difference P obtained by the angle measurement function unit 1322-1, and the phase difference −90° added by the phase difference changing unit 1322a. Estimated position information indicating the estimated position of the terminal is obtained from the estimated angle of arrival information with both +90° as the angle of arrival θ and the estimated distance information obtained by the distance measurement function section 1321, and is output to the terminal position estimation section 30. do.
The terminal position estimation unit 30 is the same as the terminal position estimation device 1 according to Embodiment 3, that is, the terminal position estimation unit 30 in the terminal position estimation device 1 according to Embodiment 1, so description thereof will be omitted.

In addition, in the relationship between the phase difference P and the arrival angle θ, when there is a plurality of arrival angles corresponding to the obtained phase difference P, the angle measurement function unit 1322-1 performs the terminal position estimation according to Embodiment 3. Similar to the angle measurement function unit 1322-1 in the device 1, a plurality of estimated arrival angle information corresponding to each of the plurality of arrival angles θ corresponding to the obtained phase difference P are obtained.

As described above, in terminal position estimation apparatus 1 according to Embodiment 4, angle measurement function section 1322-1 determines that phase difference P exceeds +180° or -180° in the relationship between phase difference P and arrival angle θ. When the reception signal from the first antenna 11 and the reception signal from the second antenna 12 are received, the arrival angle θ corresponding to the phase difference P is one. Obtaining estimated angle of arrival information with improved angle accuracy, and if there are a plurality of arrival angles θ corresponding to the phase difference P, a plurality of pieces of estimated arrival angle information corresponding to each of the plurality of arrival angles θ are obtained. It can be estimated with higher accuracy.

Furthermore, in the relationship between the phase difference P and the arrival angle θ, assuming that there is an arrival angle after folding with respect to the phase difference P of the received signal obtained, corresponding to the phase difference changed in the phase difference change range, Since the arrival angle corresponding to the phase difference after the phase difference change and after folding is added as the estimated arrival angle, for example, the plurality of antennas 11 of the stationary device 10, Even if there is an error in the phase difference of the received signal due to the incoming wave from the terminal 20 received by the terminal 12, the position of the terminal 20 can be estimated with higher accuracy.

Embodiment 5.
A terminal position estimation device 1 according to Embodiment 5 will be described with reference to FIGS. 15 and 16. FIG.
In the terminal position estimation device 1 according to Embodiment 5, each of the plurality of fixed devices 10 in the terminal position estimation device 1 according to Embodiment 1 has a ranging function and an angle measurement function, and indicates the estimated position of the terminal. While obtaining a plurality of pieces of estimated position information, at least one of the plurality of stationary devices 10 does not have an angle measurement function, and is different in that it obtains estimated distance information by a distance measurement function. As a result, although the operation of the terminal position estimation unit 30 is different, other points are the same.

That is, the terminal position estimation device 1 according to Embodiment 5 divides the plurality of fixed devices 10 into first G and second G, and the first G fixed device 10 has a ranging function and an angle measuring function. and obtains a plurality of pieces of estimated position information indicating the estimated position of the terminal, and the second G fixed device 10 obtains estimated distance information by the distance measurement function.
The first G fixed machine 10 is preferably plural, and may be one, and the second G fixed machine 10 may be one or plural.

In the terminal position estimation device 1 according to Embodiment 5, the plurality of fixed devices 10 shown as one example in the terminal position estimation device 1 according to Embodiment 1 are replaced by the first fixed device 10A and the second fixed device 10A. In the case of the fixed device 10B, the first fixed device 10A is the same as the fixed device 10 in the terminal position estimation device 1 according to Embodiment 1, and the second fixed device 10B has the angle measurement function in the received signal processing unit 132. does not have

Therefore, the reception signal processing section 132B and the terminal position estimation section 30 in the second fixed device 10B will be mainly described. Description of the first stationary device 10A is omitted.
15 and 16, the same reference numerals as those in FIGS. 1 to 8 indicate the same or corresponding parts.

The second stationary device 10B will be described below.
As shown in FIG. 16, the second stationary device 10B includes a transmitting/receiving antenna 11B and a transmitting/receiving section 13B.
The transmission/reception unit 13B includes a transmission signal processing unit 131B that outputs a transmission signal to the transmission/reception antenna 11B, and a reception signal processing unit 132B that has a distance measurement function unit 1321B that processes the reception signal from the transmission/reception antenna 11B and outputs estimated distance information. Prepare.
The transmission/reception antenna 11B receives a transmission signal from the transmission signal processing unit 131, radiates a transmission wave composed of radio waves into space, receives a return wave from the antenna 21 of the terminal 20 as an incoming wave, and generates a received signal based on the incoming wave. to output

The ranging function unit 1321B receives the transmission signal output to the transmission/reception antenna 11B and the reception signal output from the transmission/reception antenna 11B that received the return wave radiated from the antenna 21 of the terminal 20, and receives the input transmission signal. and the received signal, the distance to the terminal 20 is estimated, and output to the terminal position estimating section 30 as estimated distance information.

The terminal position estimating unit 30 corresponds to the estimated position indicated by each of the plurality of estimated position information in the first fixed device 10A and the second position indicated by the estimated distance information in the second fixed device 10B. and the estimated position on the circumference centered on the stationary device 10B, determine the shortest distance between the combined estimated position and the estimated position on the circumference, and determine the shortest distance Estimated position information in the fixed device 10A is obtained, and the obtained estimated position information is output to the display device 40. FIG.

In the example shown in FIG. 15, the terminal position estimating unit 30 assumes the estimated position PA1 indicated by the estimated position information in the first fixed device 10A, the estimated position PA1 indicated by the estimated distance information in the second fixed device 10B, and the second The shortest distance d1 between the estimated position on the circumference of the plane containing the antenna 11B of the fixed device 10B and the estimated position PA2 indicated by the estimated position information of the first fixed device 10A and the second fixed device 10B Calculate the shortest distance d2 between the estimated position PA2 indicated by the estimated distance information and the estimated position on the circumference of the plane containing the antenna 11B of the second stationary device 10B, and calculate the shortest distance d2 from the estimated position PA2 indicating the shortest distance d2 is selected as the probable location for the terminal 20 .

Therefore, the more probable estimated position information selected from the plurality of estimated position information output from the first stationary device 10A, in this example, the estimated position information indicating the estimated position PA2 is displayed on the display 40.

The terminal position estimating unit 30 includes position information indicated by the estimated position information of the first fixed device 10A with the shortest distance and the antenna 11B of the second fixed device 10B as the position information indicating the probable position. Estimated position information indicating intermediate positions of the estimated positions on the circumference of the plane may be output to the display 40 .

Further, although the first fixed machine 10A, which is the fixed machine 10 of the first G, is the fixed machine 10 shown in the first embodiment, the following may be used.
That is, in the first fixed device 10A, similarly to the first fixed device 10A shown in Embodiment 2, the angle measurement function unit 1322 receives the signal from the first antenna 11A and from the second antenna 12A. has a phase difference changing unit 1322a that changes the value of the phase difference within a predetermined phase difference change range with respect to the obtained phase difference P between the received signal and the When the phase difference exceeds +180° or falls below -180° in the phase difference change range, the phase difference after the phase difference changes when the amount of change in the phase difference is the smallest, that is, the amount of change in the phase difference is the smallest. Assume that the arrival angle corresponding to the phase difference after aliasing is obtained as additional estimated arrival angle information.

In the first stationary device 10A, similarly to the first stationary device 10A shown in Embodiment 3, the angle measurement function unit 1322 determines that the phase difference P is +180° in the relationship between the phase difference P and the arrival angle θ. When receiving the received signal from the first antenna 11 and the received signal from the second antenna 12 that are in a relationship of being folded over or below −180°, the arrival angle θ corresponding to the phase difference P is one. , it is possible to obtain estimated angle-of-arrival information with improved angle measurement accuracy, and if there are a plurality of arrival angles θ corresponding to the phase difference P, a plurality of estimated arrival angle information corresponding to each of the plurality of arrival angles θ is obtained. do.

In the first fixed device 10A, similarly to the first fixed device 10A shown in Embodiment 4, the angle measurement function unit 1322 determines the relationship between the phase difference P and the arrival angle θ from the first antenna 11A. If there is an arrival angle θ after folding with respect to the obtained phase difference P between the received signal from the second antenna 12A and the received signal from the second antenna 12A, a predetermined phase difference change range for the obtained phase difference P When the amount of change in the phase difference corresponding to the phase difference changed in the phase difference change range is the smallest After the phase difference is changed, the arrival angle corresponding to the phase difference after aliasing is obtained as additional estimated arrival angle information.

As described above, the terminal position estimation apparatus 1 according to Embodiment 5 corresponds to the estimated position indicated by each of the plurality of pieces of estimated position information in the first fixed device 10A, and each of the plurality of pieces of estimated position information. combining the estimated position on the circumference centering on the second fixed device 10B indicated by the estimated distance information of the fixed device 10B, and obtaining the shortest distance between the combined estimated position and the estimated position on the circumference Since the position of the terminal 20 is estimated by obtaining the estimated position of the combination that minimizes the obtained shortest distance and the estimated position on the circumference as the estimated position information of the combination, the position of the terminal 20 is estimated. Even if there is an error in the phase difference P of the received signals of the incoming waves from the terminal 20 received by the plurality of antennas, the position of the terminal 20 can be estimated with high accuracy.

Embodiment 6.
A vehicle radio apparatus according to Embodiment 6 will be described with reference to FIGS. 17 and 18. FIG.
A vehicle wireless communication system, which is a vehicle keyless system, includes a vehicle wireless device and a terminal 20 .
The vehicle radio apparatus according to the sixth embodiment corresponds to any one of the terminal position estimation apparatuses 1 shown in the first to fifth embodiments.
The terminal 20 is a keyless portable device of a keyless system that includes an antenna 21 and a transmitter/receiver 22 .

There are a plurality of vehicle radio devices inside the passenger compartment 101 of the vehicle 100. For example, four communication devices are installed near the four sides of the passenger compartment 101, that is, the left side, the right side, the front side, and the rear side. and a terminal position estimation unit 30 mounted in the vehicle 100 .
The fixed machines 10A to 10D correspond to any one of the fixed machines 10 shown in the first to fifth embodiments.

The first fixed machine 10A is arranged in the vicinity of the left side in the passenger compartment 101, the second fixed machine 10B is arranged in the vicinity of the right side in the passenger compartment 101, and the third fixed machine 10C is arranged in the passenger compartment 101. It is arranged in the vicinity of the front side, and the fourth fixed machine 10D is arranged in the vicinity of the rear side in the passenger compartment 101 .
The first antennas 11A to 11D and the second antennas 12A to 12D of the first fixed machine 10A to the fourth fixed machine 10D are erected vertically.

The arrangement direction of the first antennas 11A to 11D and the second antennas 12A to 12D is perpendicular to the sides of the vehicle compartment 101 on the horizontal plane.
That is, in the horizontal plane, the arrangement direction of the first antenna 11A and the second antenna 12A is perpendicular to the left side of the vehicle interior 101, and the arrangement direction of the first antenna 11B and the second antenna 12B is the direction of the vehicle interior 101. The direction perpendicular to the right side, the direction in which the first antenna 11C and the second antenna 12C are arranged is the direction perpendicular to the front side of the vehicle interior 101, and the direction in which the first antenna 11D and the second antenna 12D are arranged is the direction of the vehicle. It is oriented perpendicular to the rear side of the chamber 101 .

The arrangement direction of the first antennas 11A to 11D and the second antennas 12A to 12D is set to be perpendicular to the side of the vehicle interior 101 on the horizontal plane, thereby allowing the first fixed machine 10A to the fourth fixed machine Each 10D can determine whether the terminal 20 exists inside the vehicle interior 101 or outside the vehicle interior 101 by obtaining the arrival angle θ with respect to the terminal 20 .

The first antennas 11A to 11D can radiate transmission waves in all directions and receive incoming waves from all directions.
The second antennas 12A-12D can receive incoming waves from all directions.

As shown in FIG. 18, the first fixed device 10A to the fourth fixed device 10D have the same configuration as any one of the first fixed device 10A shown in the first to fourth embodiments.
Further, the first fixed machine 10A to the fourth fixed machine 10D have three fixed machines of the same configuration as the first fixed machine 10A shown in Embodiment 5, and the remaining one fixed machine is the first fixed machine. 2 may have the same configuration as the fixed device 10B.
Therefore, the description of the first fixed device 10A to the fourth fixed device 10D is omitted.

The terminal position estimation unit 30 includes an input interface 31, a storage unit 32, a two-point distance calculation unit 33, a selection unit 34, and an output interface 35, as shown in FIG.
The terminal position estimation unit 30 is composed of a CPU, a RAM, and a ROM. A program stored in the ROM is loaded into the RAM, and the CPU executes various processes based on the program loaded into the RAM. The processing shown is executed. The terminal position estimation unit 30 is driven by a general-purpose OS.
The reception signal processing units 132 in the first fixed device 10A to the fourth fixed device 10D may also be incorporated together with the terminal position estimation unit 30 into hardware configured by a CPU, a RAM, and a ROM.

The terminal position estimating section 30 operates in the same manner as the terminal position estimating section 30 shown in Embodiments 1 to 5.
That is, the terminal position estimating unit 30 uses a plurality of estimated position information from the first fixed device 10A, a plurality of estimated position information from the second fixed device 10B, and a plurality of estimated position information from the third fixed device 10C. Receive position information and a plurality of pieces of estimated position information from the fourth fixed device 10D, combine each estimated position information of each fixed device 10 with each other, and distance or shortest distance between estimated positions indicated by the combined estimated position information is obtained, and the estimated position information of the combination that minimizes the obtained distance is obtained.

In particular, the two-point distance calculation unit 33 calculates the distance between the estimated position indicated by each of the plurality of estimated position information from the first fixed device 10A and the estimated position indicated by each of the plurality of estimated position information from the second fixed device 10B. , the distance between the estimated position indicated by each of the plurality of estimated position information from the first fixed device 10A and the estimated position indicated by each of the plurality of estimated position information from the third fixed device 10C, the first fixed device distance between the estimated position indicated by each of the plurality of estimated position information from 10A and the estimated position indicated by each of the plurality of estimated position information from the fourth fixed device 10D, and the plurality of estimated position information from the second fixed device 10B The distance between the estimated position indicated by each and the estimated position indicated by each of the plurality of estimated position information from the third fixed device 10C, the estimated position indicated by each of the plurality of estimated position information from the second fixed device 10B and the fourth distance between the estimated positions indicated by each of the plurality of estimated position information from the fixed device 10D, and the estimated position indicated by each of the plurality of estimated position information from the third fixed device 10C and the distance between the estimated position indicated by each of the plurality of estimated position information from the third fixed device 10D The distance between the estimated positions indicated by each of the plurality of estimated position information is calculated, and the calculated result is linked to each of the estimated position information from the two stationary devices 10 and output to the storage unit 32 as combined estimated position information.

The terminal position estimation unit 30 combines the estimated position information from the first fixed device 10A to the fourth fixed device 10D with each other, and obtains the distance or the shortest distance between the estimated positions indicated by the combined estimated position information. , the estimated position information of the combination that minimizes the obtained distance is obtained. It is also possible to obtain the estimated position information of the combination.
When selecting two or three fixed devices 10, it is preferable to select the fixed devices 10 having the highest received signal power in order.

As described above, the vehicle radio apparatus according to Embodiment 6 accurately locates the terminal 20, which is a keyless portable device of the keyless system, as is clear from the descriptions of Embodiments 1 to 5. can be estimated.

It should be noted that it is possible to freely combine each embodiment, modify any component of each embodiment, or omit any component from each embodiment.

A terminal position estimation device according to the present disclosure is applied to a device for estimating the position of a terminal in wireless communication between a fixed device and a terminal, and is applied to a mobile communication system or a vehicle wireless device, particularly a keyless system that is a vehicle wireless device. is preferred.

1 Terminal position estimation device, 10, 10A to 10D Fixed devices, 11, 11A to 11D First antenna, 12, 12A to 12D Second antenna, 13, 13A to 13D Transmission/reception unit, 131 Transmission signal processing unit, 132 Reception Signal processing unit 1321 Ranging function unit 1322, 1322-1 Angle measurement function unit 1322a Phase difference change unit 1323 Estimated position output unit 20 Terminal 21 Antenna 22 Transmitting/receiving unit 30 Terminal position estimating unit 33 2 Point-to-point distance calculation unit, 34 selection unit.

Claims

Equipped with a plurality of fixed units arranged at different positions and an estimated position estimating unit,
Each of the plurality of fixed devices has a ranging function for estimating the distance to a terminal, and the arrival angle of the radio wave from the terminal is determined by the phase difference of the received signal of the radio wave from the terminal received using a plurality of antennas. obtaining estimated position information indicating an estimated position of the terminal based on a distance estimated by the ranging function and an arrival angle estimated by the ranging function;
At least one fixed device among the plurality of fixed devices has a plurality of different estimates indicating an estimated position of the terminal according to each of a plurality of distances estimated by the ranging function and angles of arrival estimated by the angle measurement function. get location information,
The estimated position estimating unit combines the estimated position information of the plurality of stationary devices located at different positions from each other, calculates the distance between the estimated positions indicated by the combined estimated position information, and finds the minimum distance. Obtain the estimated location information for the combination of
Terminal position estimation device.
The terminal position estimation device according to claim 1, wherein the estimated position estimation unit outputs estimated position information of a combination that minimizes the distance between estimated positions.
2. The terminal position estimation device according to claim 1, wherein the estimated position estimation unit outputs estimated position information indicating an intermediate position between two estimated positions indicated by a combination of estimated position information that minimizes the distance between the estimated positions. .
2. The terminal position according to claim 1, wherein the estimated position estimating unit outputs one of estimated position information selected based on a selection criterion for a combination of estimated position information that minimizes the distance between the estimated positions. estimation device.
The angle measurement function of at least one fixed device among the plurality of fixed devices is a phase difference change function of changing the value of the phase difference within a phase difference change range with respect to the phase difference of the received signal by radio waves from the terminal. and the arrival angle corresponding to the phase difference after the phase difference change when the amount of change in the phase difference is the smallest when the phase difference exceeds +180° or falls below -180° in the phase difference change range is added as the estimated arrival angle.
The terminal position estimation device according to any one of claims 1 to 5, wherein the distance between adjacent antennas in each of the plurality of fixed units is half the wavelength of radio waves from the terminal.
7. The terminal position according to claim 6, wherein the plurality of estimated arrival angles for at least one fixed device among the plurality of fixed devices are arrival angles estimated multiple times within a set measurement time by the angle measurement function. estimation device.
The plurality of estimated arrival angles at at least one fixed device among the plurality of fixed devices are a phase difference between a received signal of radio waves from the terminal and a radio wave from the terminal received using the plurality of antennas. The relationship between the arrival angle of and the phase difference exceeds +180 ° or falls below -180 °, and at any phase difference, the arrival estimated by the presence of a plurality of the arrival angles corresponding to the phase difference 6. The terminal position estimation device according to any one of claims 1 to 5, which is an angle.
The plurality of estimated arrival angles at at least one fixed device among the plurality of fixed devices are a phase difference between a received signal of radio waves from the terminal and a radio wave from the terminal received using the plurality of antennas. The relationship between the arrival angle of and the phase difference exceeds +180 ° or falls below -180 °, and at any phase difference, the arrival estimated by the presence of a plurality of the arrival angles corresponding to the phase difference is the angle and
The angle measurement function of at least one fixed device among the plurality of fixed devices is a phase difference change function of changing the value of the phase difference within a phase difference change range with respect to the phase difference of the received signal by radio waves from the terminal. have a
In the relationship between the phase difference and the arrival angle, assuming that there is an arrival angle after folding with respect to the phase difference of the received signal, a change in the phase difference corresponding to the phase difference changed in the phase difference change range. 5. The terminal position according to any one of claims 1 to 4, wherein the arrival angle corresponding to the phase difference after the phase difference change and after aliasing when the amount is the smallest is added as the estimated arrival angle. estimation device.
10. Any one of claims 1 to 5, 8, and 9, wherein the distance between adjacent antennas in each of the plurality of fixed units is a value exceeding 1/2 of the wavelength of radio waves from the terminal. 2. The terminal position estimation device according to claim 1.
It has a ranging function for estimating the distance to the terminal and an angle measurement function for estimating the arrival angle of the radio wave from the terminal based on the phase difference of the received signal of the radio wave from the terminal received using a plurality of antennas. a first stationary device for obtaining a plurality of estimated position information indicating the estimated position of the terminal according to each of the estimated distance and the plurality of estimated arrival angles;
a second fixed device arranged at a position different from the first fixed device, having a distance measuring function for estimating a distance to the terminal, and obtaining the estimated distance as estimated distance information;
The estimated position indicated by each of the plurality of estimated position information of the first fixed device, and the second fixed device corresponding to each of the plurality of estimated position information and indicated by the estimated distance information of the second fixed device and the estimated position on the circumference, find the shortest distance between the combined estimated position and the estimated position on the circumference, and the estimated position and the circumference of the combination that minimizes the shortest distance an estimated position estimating unit that obtains the estimated position of the combination as estimated position information;
A terminal position estimation device with
12. The terminal position estimation device according to claim 11, wherein the estimated position estimation unit outputs the estimated position information of the first stationary device in the estimated position information of the combination that minimizes the shortest distance.
The estimated position estimating unit generates a circle indicated by the estimated position indicated by the estimated position information of the first fixed device and the estimated distance information of the second fixed device in the estimated position information of the combination that minimizes the shortest distance obtained. 12. The terminal position estimation device according to claim 11, which outputs estimated position information indicating an intermediate position between estimated positions on the circumference.
The angle measurement function of the first stationary device is provided with a phase difference change function of changing a phase difference value within a phase difference change range with respect to a phase difference of a signal received by radio waves from the terminal, and the phase difference change When the phase difference exceeds +180° or falls below -180° in the range, the arrival angle corresponding to the phase difference after the phase difference change is added as the estimated arrival angle when the amount of change in the phase difference is the smallest. The terminal position estimation device according to any one of claims 11 to 13.
The terminal position estimation device according to any one of claims 11 to 14, wherein the interval between adjacent antennas in said first fixed station is half the wavelength of radio waves from said terminal.
16. The terminal position estimation device according to claim 15, wherein the plurality of estimated arrival angles at the first fixed station are arrival angles estimated multiple times within a set measurement time by the angle measurement function.
The plurality of estimated arrival angles at the first fixed station are based on the relationship between the phase difference of the received signal of the radio wave from the terminal received using the plurality of antennas and the arrival angle of the radio wave from the terminal, Said phase difference exceeds +180° or falls below -180°, and at any phase difference, it is an arrival angle estimated by the presence of a plurality of said arrival angles corresponding to said phase difference. Item 15. The terminal position estimation device according to any one of Items 14-14.
The plurality of estimated arrival angles at the first stationary device are obtained by determining the relationship between the phase difference of the received signal of the radio wave from the terminal received using the plurality of antennas and the arrival angle of the radio wave from the terminal, When the phase difference exceeds +180° or falls below -180°, any phase difference is an arrival angle estimated by the presence of a plurality of the arrival angles corresponding to the phase difference,
The angle measurement function of at least one fixed device among the plurality of fixed devices is a phase difference change function of changing the value of the phase difference within a phase difference change range with respect to the phase difference of the received signal by radio waves from the terminal. have a
In the relationship between the phase difference and the arrival angle, assuming that there is an arrival angle after folding with respect to the phase difference of the received signal, a change in the phase difference corresponding to the phase difference changed in the phase difference change range. 14. The terminal position according to any one of claims 11 to 13, wherein the arrival angle corresponding to the phase difference after the phase difference change and after aliasing when the amount is the smallest is added as the estimated arrival angle. estimation device.
19. Any one of claims 11 to 14, 17 and 18, wherein the interval between adjacent antennas in said first fixed station is a value exceeding 1/2 of the wavelength of radio waves from said terminal. The terminal position estimation device according to the item.
a ranging step in which each of a plurality of stationary devices arranged at different positions estimates a distance to a terminal;
an angle measurement step in which each of the plurality of fixed devices estimates an arrival angle of the radio waves from the terminal based on a phase difference between signals received by the radio waves from the terminal and received using a plurality of antennas;
a position estimation step in which each of the plurality of stationary devices obtains estimated position information indicating an estimated position of the terminal based on the estimated distance and the estimated arrival angle;
at least one fixed device among the plurality of fixed devices obtains a plurality of estimated position information indicating an estimated position of the terminal based on each of the estimated distance and the estimated arrival angle, and an estimated position estimating unit; combines the estimated position information of the plurality of fixed units located at different positions from each other, obtains the distance between the estimated positions indicated by the combined estimated position information, and estimates the combination that minimizes the obtained distance a combined position estimation step of obtaining position information;
A terminal position estimation method comprising:
In the angle measurement step, when the phase difference exceeds +180° or falls below -180° in a phase difference change range in which the value of the phase difference is changed with respect to the phase difference of the received signal by radio waves from the terminal 21. The terminal position estimation method according to claim 20, further comprising the step of estimating the arrival angle corresponding to the phase difference after the phase difference is changed when the amount of change in the phase difference is the smallest.
In the angle measurement step, the relationship between the phase difference of the received signal by the radio wave from the terminal and the arrival angle of the radio wave from the terminal turns back when the phase difference exceeds +180° or falls below -180°. 21. The terminal position estimating method according to claim 20, wherein the phase difference is a step of estimating the arrival angle based on the existence of a plurality of the arrival angles corresponding to the phase difference.
In the angle measurement step, the relationship between the phase difference of the received signal by the radio wave from the terminal and the arrival angle of the radio wave from the terminal turns back when the phase difference exceeds +180° or falls below -180°. In the phase difference of , the arrival angle is estimated based on the presence of a plurality of the arrival angles corresponding to the phase difference,
In the relationship between the phase difference and the arrival angle, assuming that there is an arrival angle after folding with respect to the phase difference of the received signal, the amount of change in the phase difference corresponding to the phase difference changed in the phase difference change range. 21. The terminal position estimation method according to claim 20, further comprising a step of estimating an arrival angle obtained by estimating an arrival angle corresponding to a phase difference after a phase difference change and after aliasing when is the smallest.
A ranging step in which the first stationary device estimates the distance to the terminal;
an angle measurement step in which a first stationary device estimates multiple arrival angles of radio waves from the terminal based on phase differences between signals received by the radio waves from the terminal and received using a plurality of antennas;
a position estimation step in which a first fixed station obtains a plurality of estimated position information indicating estimated positions of the terminal according to each of the estimated distance and a plurality of estimated arrival angles;
A ranging step in which the second stationary device estimates the distance to the terminal;
The estimated position estimating unit corresponds to the estimated position indicated by each of the plurality of estimated position information in the first fixed device, and the estimated position indicated by the estimated distance information in the second fixed device, each corresponding to the plurality of estimated position information. Combining the estimated position on the circumference centered on the fixed machine in 2, finding the shortest distance between the combined estimated position and the estimated position on the circumference, and finding the combination that minimizes the shortest distance a combined position estimation step of obtaining the estimated position and the estimated position on the circumference as combined estimated position information;
A terminal position estimation method comprising:
A vehicle radio device that performs radio communication with a keyless portable device,
A plurality of communication devices mounted inside a cabin in a vehicle, and a terminal position estimation unit mounted in the vehicle,
The plurality of communication devices are composed of a plurality of stationary devices in the terminal position estimation device according to any one of claims 1 to 19,
The terminal location estimating unit combines a plurality of pieces of estimated location information of the plurality of communication devices with each other, obtains a distance between estimated locations indicated by the combined estimated location information, and estimates a combination that minimizes the obtained distance. A vehicle radio device that obtains location information.