JP7433546B2 - Terminal position estimation device, terminal position estimation method, and vehicle radio device - Google Patents

Description

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

A system in which a fixed device and a terminal communicate wirelessly uses technology to estimate the location of the terminal. As means for estimating the position of a terminal, there are distance measurement, which measures the distance from a fixed device to the terminal, and angle measurement, which measures the direction of the terminal as seen from the fixed device.

An example of distance measurement 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 placed on a fixed device, radio waves from a terminal are received by the multiple receiving antennas placed on the fixed device, and the direction of the terminal is determined from the phase difference between the received incoming waves. There is a way.
As a method for estimating the arrival direction of such radio waves, various angle measurement algorithms are shown in Non-Patent Document 1.

The position of the terminal can be estimated by performing distance measurement and angle measurement using a fixed device.
Furthermore, it is possible to install a fixed device at each of a plurality of locations, estimate the distance to the terminal using each fixed device, and determine the location of the terminal by multilateration.
Alternatively, fixed devices may be installed at each of a plurality of locations, the direction of the terminal may be estimated by each fixed device, and the location of the terminal may be determined by triangulation.

Yamada, “Array calibration method for high-resolution direction of arrival estimation,” IEICE Transactions B, Vol. J92B, No. 9, pp. 1308-1321.

However, when angle measurement is performed using the phase of the arriving wave obtained by each of the multiple receiving antennas placed on a fixed device, if there is an error in the phase of the received signal based on the arriving wave, the angle measurement may be incorrect. .
In particular, when the phase difference between multiple antennas exceeds 180° or is less than -180°, the phase difference of the received signals received by the multiple antennas is folded back, and the result of estimating the location of the terminal is different from the actual location of the terminal. There is a large deviation from the position.

In addition, if the interval between multiple receiving antennas placed on a fixed device is larger than half the wavelength of the arriving wave, even if there is no error in the phase of the received signal based on the arriving wave, the position of the received signal due to the multiple receiving antennas will be A aliasing occurs in the relationship between the phase difference and the angle of arrival of the arriving wave.
If a alias occurs in the relationship between the phase difference and the angle of arrival, multiple values of the angle of arrival will occur corresponding to the phase difference, and the direction of the terminal will not be uniquely determined, leading to incorrect angle measurements.

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

A terminal position estimating device according to the present disclosure includes a plurality of fixed devices and a terminal position estimating unit arranged at different positions, and each of the plurality of fixed devices has a ranging function for estimating the distance to the terminal, and a plurality of fixed devices for estimating the distance to the terminal. It has an angle measurement function that estimates the arrival angle of radio waves from a terminal based on the phase difference of the received signal due to the radio waves received from the terminal using an antenna . Estimated position information indicating the estimated position of the terminal based on angle is obtained, and at least one of the plurality of fixed devices detects the terminal based on the distance estimated by the distance measurement function and the arrival angle estimated by the angle measurement function. The terminal position estimator obtains a plurality of pieces of estimated position information indicating the estimated positions of , and obtain the estimated position information of the combination that minimizes the distance.

According to the present disclosure, the position of a terminal can be estimated with high accuracy even if an error occurs in the phase difference of a received signal due to an incoming wave from a terminal received by a plurality of antennas of a fixed device.

1 is a configuration diagram showing a wireless communication system including a terminal position estimating device according to Embodiment 1. FIG. 2 is a block diagram showing the configuration of a transmitting and receiving unit in the terminal position estimating device according to Embodiment 1. FIG. FIG. 2 is a schematic block diagram showing the configuration of a fixed device and a terminal position estimating section in the terminal position estimating device according to the first embodiment. FIG. 3 is a diagram showing the difference in optical path length of radio waves received by a first antenna and a second antenna. A diagram showing the relationship between the phase difference P and the angle of arrival 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. It is. In the terminal position estimating device according to the first embodiment, the arrangement interval between the first antenna and the second antenna is λ/2, and when an error factor occurs, reception by the first antenna and the second antenna is performed. FIG. 3 is a diagram illustrating an example of the relationship between the phase difference P and the angle of arrival θ in radio waves. In the terminal position estimating device according to the first embodiment, the arrangement interval between the first antenna and the second antenna is λ/2, and when an error factor occurs, reception by the first antenna and the second antenna is performed. FIG. 3 is a diagram illustrating another example of the relationship between the phase difference P and the angle of arrival θ in radio waves. 3 is a flowchart showing the operation of the terminal position estimating device according to the first embodiment. FIG. 2 is a block diagram showing the configuration of a transmitting/receiving section in a terminal position estimating device according to a second embodiment. In the terminal position estimating device according to the second embodiment, the arrangement interval between the first antenna and the second antenna is λ/2, and when an error factor occurs, reception by the first antenna and the second antenna is performed. FIG. 3 is a diagram illustrating an example of the relationship between the phase difference P and the angle of arrival θ in radio waves. FIG. 3 is a block diagram showing the configuration of a transmitting/receiving section in a terminal position estimating device according to Embodiment 3. FIG. In the terminal position estimating device according to Embodiment 3, in the relationship between the phase difference P between the radio waves received by the first antenna and the second antenna and the angle of arrival θ, the phase difference P exceeds +180° or -180°. 3 is a diagram illustrating an example of the relationship between the phase difference P and the angle of arrival θ, in which a plurality of angles of arrival θ corresponding to the phase difference P exist for any one of the phase differences P. FIG. 7 is a block diagram showing the configuration of a transmitting and receiving unit in a terminal position estimating device according to Embodiment 4. FIG. In the terminal position estimating device according to the fourth embodiment, in the relationship between the phase difference P between the radio waves received by the first antenna and the second antenna and the angle of arrival θ, the phase difference P exceeds +180° or -180°. An example of the relationship between the phase difference P and the angle of arrival θ when an error factor occurs, where there are multiple arrival angles θ corresponding to the phase difference P for any phase difference P, will be explained. This is a diagram. FIG. 7 is a configuration diagram showing a wireless communication system including a terminal position estimating device according to a fifth embodiment. 12 is a block diagram showing the configuration of a transmitting and receiving unit in a terminal position estimating device according to Embodiment 5. FIG. FIG. 7 is a configuration diagram showing a vehicle wireless communication system including a vehicle wireless device according to a sixth embodiment. FIG. 7 is a schematic block diagram showing the configuration of a fixed device and a terminal position estimating unit in a vehicle wireless device according to a sixth embodiment.

Embodiment 1.
A terminal position estimating device 1 according to Embodiment 1 will be described with reference to FIGS. 1 to 8.
The wireless communication system includes a terminal position estimation device 1 and a terminal 20.
The terminal position estimating device 1 includes a plurality of fixed devices, in this example, a first fixed device 10A and a second fixed device 10B, and a terminal position estimation section 30.
The 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.

Note that although the first fixing device 10A and the second fixing device 10B are used as the fixing devices, the number is not limited to two, and a plurality of three or more may be used. Even in a plurality of three or more fixed machines, each fixed machine has the same configuration and performs the same operation.
Further, in order to avoid complexity, the first fixing device 10A and the second fixing device 10B will be described as the fixing device 10 unless it is necessary to explain them individually.

When the wireless 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 wireless communication system of the present disclosure is used as 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 explanation will be omitted as it 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.
The following explanation will be given simply as the fixed device 10 and the terminal 20.

Each of the plurality of fixed devices 10 has a distance measurement function that estimates the distance to the terminal 20, and an angle measurement function that estimates the direction to the terminal 20, that is, the angle of arrival of radio waves from the terminal 20 multiple times within a set measurement time. and obtains a plurality of pieces of estimated position information indicating the estimated position of the terminal 20 based on the estimated distance and the plurality of estimated angles of arrival. The plural pieces of estimated position information are output to the terminal position estimation section 30.
The plurality of fixing machines 10 are arranged at different positions.

Note that not all of the plurality of fixed devices 10 output plural pieces of estimated position information, and if there is no room to generate plural pieces of estimated position information, there may be cases where there are fixed devices 10 that do not output plural pieces of estimated position information. be.
However, when at least one of the plurality of fixed devices 10 outputs a plurality of pieces of estimated position information, the terminal position estimating device 1 according to the first embodiment functions effectively.
In the following description, in order to avoid complexity, it will be assumed that all of the plurality of fixed devices 10 output a plurality of pieces of estimated position information.

Each fixed device 10 includes a plurality of antennas; in this example, the first fixed devices 10A, 10B include first antennas 11A, 11B, second antennas 12A, 12B, and transmitting/receiving sections 13A, 13B.
Note that although there are two antennas, the first antennas 11A, 11B and the second antennas 12A, 12B, for each of the first fixed devices 10A, 10B, a plurality of three or more antennas may be used. In other words, the number of antennas may be plural.
Hereinafter, in order to avoid complexity, 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 transmitter/receiver 13, unless it is necessary to explain them separately. do.

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

The first antenna 11 emits radio waves into space, receives radio waves from space as arriving waves, and outputs a received signal based on the arriving waves.
The second antenna 12 receives radio waves from space as arriving waves, and outputs a received signal based on the arriving waves.

As shown in FIG. 2, the transmitter/receiver 13 includes a transmit signal processor 131 that outputs a transmit signal to the first antenna 11, and processes and estimates received signals from the first antenna 11 and the second antenna 12. It has a received signal processing section 132 that outputs position information.

The received signal processing section 132 of the transmitting/receiving section 13 includes a distance measurement function section 1321, an angle measurement function section 1322, and an estimated position output section 1323.
The distance measurement function section 1321, the angle measurement function section 1322, and the estimated position output section 1323 are composed of 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 a program into the RAM and causing the CPU to execute various processes based on the program loaded into the RAM. The angle measurement function section 1322, the angle measurement function section 1322, and the estimated position output section 1323 are driven by a general-purpose OS (Operating System).

The ranging function unit 1321 receives the transmission signal outputted to the first antenna 11 and the reception signal outputted 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 based on the transmitted and received signals.

The angle measurement function unit 1322 receives the received signals output from the first antenna 11 and the second antenna 12 that received the return waves radiated from the antenna 21 of the terminal 20, and receives the received signals from the input first antenna 11. 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 using the received signal output from the second antenna 12 and the received signal output from the second antenna 12.

The estimated position output unit 1323 outputs a plurality of pieces of estimated position information indicating the estimated position of the terminal based on the estimated distance information obtained by the ranging function unit 1321 and the plurality of estimated arrival angle information obtained by the angle measurement function unit 1322. It is output to the terminal position estimating section 30.
The estimated position information is information indicating an estimated position obtained by converting a pair of a distance based on estimated distance information and an angle of arrival based on estimated angle of arrival information into spatial coordinates.
The estimated position information is three-dimensional coordinate information, for example, the arrangement direction of the first antenna 11 and the second antenna 12 is the x axis, the vertical direction is the y axis, and the direction orthogonal to the x axis and the y axis is the z axis. It is expressed by the x, y, and z coordinates of 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 measuring function unit 1321 estimates the distance to the terminal 20 using a method using communication propagation time.

Based on the transmission signal output from the transmission signal processing section 131 of the transmission/reception section 13, the first antenna 11 radiates a transmission wave consisting of radio waves toward space.
The transmission wave radiated from the first antenna 11 is received by the antenna 21 of the terminal 20 and inputted 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 to the antenna 21 based on the input received signal, and a reply wave in the form of radio waves is radiated into space from the antenna 21.

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

The ranging function unit 1321 obtains the time required for signal processing by the transmitting/receiving unit 13 and the time required for signal processing by the transmitting/receiving unit 22 of the terminal 20 from the measured time as the round-trip propagation time.
The distance measurement function unit 1321 calculates estimated distance information indicating the estimated distance from the fixed device 10 to the terminal 20 by setting 1/2 of the round-trip propagation time as the one-way 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 processes the received signal from the first antenna 11 and the second antenna 12 of the fixed device 10. The direction of the terminal 20, that is, the angle of arrival, is estimated from the phase difference P between the terminal 20 and the antenna 21, and estimated angle of arrival information indicating the estimated angle of arrival of the arriving wave from the antenna 21 of the terminal 20 is obtained.
The angle measurement function unit 1322 obtains estimated arrival angle information of the arriving 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 assumed to be 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 arriving wave at an angle θ between the x-axis and the y-axis (y direction, vertical direction) orthogonal to the x-axis. Suppose you arrive at

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 expressed by the following equation (1).
D=dsinθ...(1)

The phase difference P between the arriving wave received by the first antenna 11 and the arriving wave received by the second antenna 12 is expressed by the following equation (2).
P=k・D=k・dsinθ...(2)
k is a wave number, 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.

For the phase difference P, the following equation (5) is obtained by substituting the above equation (4) into the above equation (3) and substituting into the above equation (2).
P=k・dsinθ=(2π/λ)・dsinθ=(2π/(C/f))・dsinθ
=(2πf/C)・dsinθ...(5)

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

In FIG. 4, the optical path length difference and the phase difference P are the same even when the arriving wave is 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, the explanation will be made assuming that the arrangement direction of the first antenna 11 and the second antenna 12 and the direction of the arriving wave are on the xy plane.

Furthermore, even when it is assumed that the arrangement direction of the first antenna 11 and the second antenna 12 and the direction of the arriving wave are on the xy plane, the arrival angle of the arriving wave is θ and (180°−θ ), the optical path length difference and phase difference P are the same.
Due to the directivity of the first antenna 11 and the second antenna 12, if radio waves from the -y direction, that is, radio waves whose direction of arriving waves is (180°-θ), are not received, there is only one direction of arriving waves. 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 section 1322 of the received signal processing section 132 receives the received signals from the first antenna 11 and the second antenna 12 of the fixed device 10, which have received the return wave from the antenna 21 of the terminal 20 as an arriving wave. By determining the phase difference P at , the angle of arrival θ of the arriving wave from the antenna 21 can be determined.

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

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

In FIG. 6, a solid line T shows the ideal relationship between the phase difference P and the angle of arrival θ, and a broken line F shows the relationship between the phase difference P and the angle of arrival θ in which an error occurs in the phase difference due to the above-mentioned causes.
The solid line T is an ideal value obtained from the above equation (5) assuming that there is no error in the phase difference P, and is the same as the solid line T shown in FIG.
A broken line F indicates the relationship between the phase difference P having an error and the angle of arrival θ, and assumes that +60° is added as an error to the phase difference P.
In other words, the broken line F indicates that, with respect to the arrival angle θ, the phase difference P is shifted by +60° from the ideal phase difference P.
Note that the +60° error is an example in which a large error is given for the sake of explanation.

For example, it is assumed that the arrival angle θ of the arriving waves to the first antenna 11 and the second antenna 12 is 0°.
In this case, according to the above equation (5), the phase difference P between the received signal from the first antenna 11 and the received signal from the second antenna 12 is ideal as shown by the star in FIG. is 0°.

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

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

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

On the other hand, when +60° is added as an error to the phase difference P, the phase difference P obtained by the angle measurement function unit 1322 is 60°, the arrival angle θ determined by the above equation (5) is 20°, and the angle measurement There is a difference between the estimated angle of arrival θ obtained by the functional unit 1322 and the true angle of arrival 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.

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

Assuming that +60° is added to the phase difference P as an error, the received signal from the first antenna 11 indicates that the arrival angle θ of the arriving waves to the first antenna 11 and the second antenna 12 is 60°. The phase difference P between the received signal from the second antenna 12 is 215° (=155+60).
Since the phase rotates in 360°, a phase difference P exceeding +180° or less than −180° cannot be distinguished from a phase difference P within ±180°. That is, even if a value that is an integer multiple of 360° is added or subtracted from the phase value, it becomes the same as the original phase value. In this example, the phase difference of 215° is synonymous with -145° (=215-360).
The phase difference P of −145° is shown in FIG. 7 by a black circle.

When the phase difference P is −145°, the angle measurement function unit 1322 sets the estimated arrival angle θ to −54° using the above equation (5).
That is, the angle measurement function unit 1322 obtains an estimated angle of arrival θ that is different from the true angle of arrival θ. In this case, as the sign of the phase difference P is reversed, an extreme deviation occurs in the estimated angle of arrival θ.
In this way, although the terminal 20 is not moving, the estimated arrival angle θ obtained by the angle measurement function unit 1322 takes two values, 60° and -54°, depending on the time.

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

Therefore, in the terminal position estimating device 1 according to the first embodiment, the angle measurement function section 1322 of the received signal processing section 132 in the transmitting/receiving section 13 calculates the angle of the output from the inputted first antenna 11 within the set measurement time. Using 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 unit 1323 also outputs a plurality of pieces of estimated position information, at least two pieces, to the terminal position estimation unit 30.

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 of the first fixed device 10A outputs two estimated position information indicating different positions, and the second fixed device 10A outputs two pieces of estimated position information indicating different positions. From the estimated position output unit 1323 in the fixed device 10B, two pieces of estimated position information indicating different positions from the estimated position information output from the first fixed device 10A are output to the terminal position estimating unit 30. The following describes the case where the data is output.

Note that in both the first fixed device 10A and the second fixed device 10B, if there is no error factor and no error occurs in the phase difference P, the estimation indicated by the estimated position information output from the first fixed device 10A The position matches the estimated position indicated by the estimated position information output from the second fixed device 10B.
In order to simplify the explanation, a case will be described in which two fixed devices 10 are used and two pieces of estimated position information output from each fixed device 10 are obtained. The same can be considered in the case where three or more pieces of estimated position information are obtained from the fixed device 10.

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

The terminal position estimating unit 30 estimates the 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, the estimated position information indicating the estimated position PA1. Estimated position information indicating the position PA2 and a plurality of pieces of estimated position information obtained by the received signal processing section 132 of the transmitting/receiving section 13B in the second fixed device 10B, in this example, the estimated position information indicating the estimated position PB1 and the estimated position PB2. Based on the estimated position information indicative of The estimated position information is output to the display 40.

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

As a result, in the first fixed device 10A, the estimated position information indicating the estimated position is more reliable than the estimated position information indicating the estimated position PA1, and the estimated position information indicating the estimated position PA2 is more likely than the estimated position information indicating the estimated position PA1. Regarding 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.

Therefore, in each fixed device 10, more likely estimated position information selected from a plurality of pieces of output estimated position information is displayed on the display 40.
In particular, as explained above, even if the phase difference P exceeds +180° or falls below -180° and the phase difference is aliased, a probable position can be determined from the estimated position information indicating multiple estimated positions. It is possible to determine the estimated position information indicating the location.

Note that the terminal position estimating unit 30 selects a set indicating a likely position and outputs the estimated position information of the combination to the display 40. Estimated position information indicating an intermediate position may be output to the display 40.
Furthermore, among the combinations of estimated position information indicating likely positions, the terminal position estimating unit 30 outputs to the display 40 the estimated position information whose distance is shorter as indicated by the estimated distance information obtained by the ranging function unit 1321. It may also be something to do.

Further, the terminal position estimating unit 30 may output to the display 40 the estimated position information of the combination of estimated position information indicating a likely position, the one with the higher power of the received signal.
In short, the terminal position estimating unit 30 outputs estimated position information of a combination indicating a probable position, or outputs an estimated position of one of the combinations of estimated position information indicating a probable position based on selection criteria. The information is output to the display 40.

As shown in FIG. 3, the terminal position estimation section 30 includes an input interface 31, a storage section 32, a point-to-point distance calculation section 33, a selection section 34, and an output interface 35.
The terminal position estimating unit 30 is composed of a CPU, a RAM, and a ROM, and the 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 process 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, The first fixed device 10A and a plurality of estimated position information output from the first fixed device 10A are linked and output to the storage unit 32, and the second fixed device 10B and the second fixed device 10B output the estimated position information. The plural pieces of estimated position information are linked together and output to the storage unit 32.

The storage unit 32 stores 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.
The two-point distance calculation unit 33 reads out the plurality of estimated position information linked to the first fixed device 10A and the plurality of estimated position information linked to the second fixed device 10B 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 are combined with each other, and the distance between the estimated positions indicated by the combined estimated position information is calculated. is calculated, and the calculated result 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 outputted 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 connects the selected estimated position information to the second fixed device 10B. Find the distance to each of the linked estimated position information, and link the found distance with the estimated position information of the first fixed device 10A and the estimated position information of the second fixed device 10B from which the distance was calculated. It is stored in the storage unit 32 as combined estimated position information.

Similarly, the two-point distance calculation unit 33 links the remaining estimated position information of the plurality of estimated position information linked to the first fixed device 10A one by one to the second fixed device 10B. Find the distance to each of the attached plural pieces of estimated position information, and link and combine the found distance with the estimated position information of the first fixed device 10A and the estimated position information of the second fixed device 10B from which the distance was calculated. It is 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 at the first fixed device 10A. The estimated position information and the estimated position information indicating the estimated position PB1 in the second fixed device 10B are linked and stored in the storage unit 32 as combined estimated position information (PA1-PB1-d11).

Similarly, the two-point distance calculation unit 33 calculates the combined estimated position information (PA1-PB2-d12) for the distance d12 between the estimated position PA1 and the estimated position PB2, and the combined estimated position information (PA1-PB2-d12) for the distance d21 between the estimated position PA2 and the estimated position 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.

The selection unit 34 reads out the plurality of combined estimated position information stored in the storage unit 32, obtains the combined estimated position information with the minimum distance information in the combined estimated position information, and selects the first combination estimated position information based on the minimum combined estimated position information. A combination of estimated position information including estimated position information by the second fixed device 10A, estimated position information by the second fixed device 10B, and distance information between them is output to the display 40 via the output interface 35.

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 selected. The combined estimated position information (PA2-PB1-d21) including the estimated position information shown in FIG.

At this time, the selection unit 34 displays estimated position information indicating an intermediate estimated position PAB, which is an intermediate value between the estimated position PA2 and the estimated position PB1, on the display 40 instead of the combined estimated position information (PA2-PB1-d21). It may also be something that outputs to .
Furthermore, instead of the combination of 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 40.

Next, the operation of the terminal position estimating device 1 according to the first embodiment will be explained using the flowchart shown in FIG. 8.
To avoid complication of explanation, the plurality of fixed devices 10 are referred to 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. The following description assumes that the relationship shown in FIG. 1 exists.

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

The terminal 20 radiates a reply wave made of radio waves into space from the antenna 21 that receives the reply signal from the transmitting/receiving section 22.
Step ST2 is a step of receiving a return wave from the terminal 20 as an arriving wave.
In step ST2, the first antenna 11 and 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 section 132 of the transmitting/receiving section 13 as a received signal. Output.

Step ST3 is a distance measuring step for estimating the distance from each fixed device 10 to the terminal 20.
In step ST3, the ranging function unit 1321 of the received signal processing unit 132 in each fixed device 10 determines whether the first antenna 11 is connected to the terminal 20 from the time when the transmitted signal processing unit 131 outputs the transmission signal to the first antenna 11. The time up to the time when the received signal is output to the received signal processing section 132 after receiving the return wave 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 in which a plurality of arrival angles of return waves from the terminal 20 are estimated.
In step ST4, the angle measurement function section 1322 of the received signal processing section 132 in each fixed device 10 receives the return wave from the antenna 21 of the terminal 20 from the first antenna 11 and second antenna 12 of the fixed device 10. The arrival angle of the arriving wave from the antenna 21 of the terminal 20 is estimated from the phase difference P between the received signal and the received signal, and estimated arrival angle information indicating the estimated arrival angle is obtained.

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

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

In this example, the estimated position information obtained by the first fixed device 10A is estimated position information indicating the estimated position PA1 and estimated position information indicating the estimated position PA2.
In this example, the estimated position information obtained by the second fixed device 10B is estimated position information indicating the estimated position PB1 and estimated position information indicating the estimated position PB2.
Note that 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 estimating unit 30 stores a plurality of pieces of estimated position information from a plurality of fixed devices 10 via the input interface 31 in association with each fixed device 10.
Step ST6 is a combination step that combines estimated position information from a plurality of fixed devices 10.
In step ST6, the two-point distance calculation unit 33 in the terminal position estimating unit 30 calculates the estimated position information stored in the storage unit 32 and associated with the first fixed device 10A and the second fixed device 10B. A plurality of pieces of estimated position information linked to each other 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 links 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 it in the storage unit 32 as combined estimated position information. Output.

The two-point 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 information for the distance d12 between the estimated position PA1 and the estimated position PB2. information (PA1-PB2-d12), combination for distance d21 between estimated position PA2 and estimated position PB1, combination for estimated position information (PA2-PB1-d21), and distance d22 between estimated position PA2 and estimated position PB2 Obtain estimated position information (PA2-PB2-d22).

Step ST7 is a selection step for obtaining the optimum combination of estimated position information.
In step ST7, the selection unit 34 in the terminal position estimating unit 30 obtains the combined estimated position information that minimizes the distance information among the plurality of combined estimated position information stored in the storage unit 32.
The selection unit 34 obtains, for example, the combined estimated position information (PA2-PB1-d21) for the minimum d21.
Steps ST6 and ST7 constitute a combined position estimating step in which estimated position information from a plurality of fixed devices 10 is combined to obtain an optimal combination of estimated positions.

Step ST8 is a step of outputting the estimated position of the optimal combination.
In step ST8, the selection unit 34 outputs estimated position information based on the obtained minimum combined estimated position information to the display 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 estimated position information indicating the estimated position PA2 by the second fixed device 10B. A combination of estimated position information 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 the first fixed device 10A based on selection criteria. This is the estimated position information selected from either the estimated position information indicating PA2 or the estimated position information indicating the estimated position PB1 by the second fixed device 10B.

In the terminal position estimating device 1 according to the first embodiment described above, error factors occur 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 are output from the estimated position information indicating the estimated position PA1 and the estimated position information indicating the estimated position PA2, which indicate different positions from the first fixed device 10B. Two pieces of estimated position information, the estimated position information indicating the estimated position PB1 and the estimated position information indicating the estimated position PB2, indicate a different position from the estimated position information output from the fixed device 10A, and indicate different positions from each other. The description has been made assuming that the information is output to the terminal position estimating section 30.

However, the example is not limited to the above example, and an error factor occurs in the first fixed device 10A, and the estimated position output unit 1323 of the first fixed device 10A indicates a different position. Two different pieces of estimated position information are output: the position information and the estimated position information indicating the estimated position PA2, but there is no error factor in the second fixed device 10B, or two different pieces of estimated position information are generated. Embodiment 1 described above also applies when there is no room for this, and as a result, two different pieces of estimated position information are not output, and only one piece of estimated position information indicating the estimated position PB is output to the terminal position estimating unit 30. The terminal position estimating device 1 according to the above functions effectively.

That is, in this example, the terminal position estimating unit 30 estimates 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 fixed device 10A. , the distance between the estimated position PA1 and the estimated position PB, and the estimated position PA2 and the estimated position based on 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 PBs is calculated, the combination of estimated positions showing the minimum distance is selected as the set showing the likely position for 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 estimating device 1 according to the first embodiment, at least one of the plurality of fixed devices 10 located at different positions A plurality of different estimated position information indicating the estimated position of the terminal based on a plurality of distances and estimated angles of arrival are obtained, and the estimated position information of a plurality of fixed devices 10 disposed at different positions is combined with each other to perform the combined estimation. The position of the terminal 20 is estimated by calculating the distance between the estimated positions indicated by the position information and obtaining the estimated position information of the combination that minimizes the calculated distance. Even if there is an error in the phase difference P of the received signals due to the arriving waves 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 estimating device 1 according to Embodiment 2 will be described with reference to FIGS. 9 and 10.
The terminal position estimating device 1 according to the second embodiment has a positioning function in the angle measurement function section 1322 of at least one fixed device 10 among the plurality of fixed devices 10 in contrast to the terminal position estimating device 1 according to the first embodiment. The difference is that a phase difference changing function, that is, a phase difference changing section 1322a is added as shown in FIG. 9, and other points are the same.

That is, in the terminal position estimating device 1 according to the first embodiment, when the plurality of fixed devices 10 shown as one example are the first fixed device 10A and the second fixed device 10B, the first fixed device A phase difference changing section 1322a is added to the angle measuring function section 1322 in 10A.
The second fixed device 10B is the same as the second fixed device 10B in the terminal position estimating device 1 according to the first embodiment.

In addition, in the first fixed device 10A, in the transmitting/receiving unit 13A, components 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 used for the terminal position according to the first embodiment. The transmission signal processing unit 131, distance measurement function unit 1321, and estimated position output unit 1323 in the estimation device 1 are the same.
Therefore, the following description will focus on the angle measurement function section 1322 of the transmitter/receiver section 13A in the first fixed device 10A.
Note that in FIGS. 9 and 10, the same reference numerals as those shown in FIGS. 1 to 8 indicate the same or corresponding parts.

In the first fixed device 10A, the angle measurement function section 1322 of the received signal processing section 132 in the transmitter/receiver section 13A converts the return wave from the antenna 21 of the terminal 20 into a received signal from the first antenna 11A, which receives the return wave as an incoming wave. The phase difference P between the received signal from the second antenna 12A is determined, the arrival angle is estimated from the determined phase difference P, and estimated arrival angle information of the arriving wave from the antenna 21 of the terminal 20 is obtained.

The angle measurement function unit 1322 calculates the value of the phase difference 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, it has a phase difference changing function and changes the amount of change in phase difference when the phase difference exceeds +180° or falls below -180° in the phase difference changing range. The arrival angle corresponding to the phase difference after the phase difference change when is the smallest, that is, the phase difference after aliasing where the amount of change in the phase difference is the smallest, is obtained as additional estimated arrival angle information.

The estimated position output unit 1323 outputs an estimated position indicating the estimated position of the terminal 20 based on the additional estimated angle of arrival information obtained by the angle measurement function unit 1322 and the estimated distance information obtained by the distance measurement function unit 1321. The information is obtained and output to the terminal position estimation section 30.

Next, the operation of the angle measurement function section 1322 will be explained using an example.
Now, it is assumed that the arrival angle θ of the arriving 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 received signal from the first antenna 11A and the received signal from the second antenna 12A is ideal as shown by the star in FIG. +155°.

Adding the error factor to 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 position where the phase difference P is −175° is indicated by a black circle.
When the phase difference P is −175°, the angle measurement function unit 1322 sets the estimated angle of arrival θ to −77° using the above equation (5).
In other words, the fact that the phase difference P is -175° means that the ideal phase difference +155° is folded back by +180°, and there is no folding between the original phase difference P and the obtained phase difference P. Due to this, the angle measurement function unit 1322 obtains an estimated angle of arrival θ that is different from the true angle of arrival θ.

In this way, when aliasing occurs in the phase difference P, it is assumed that an error has been added to the obtained phase difference P, and the value of the phase difference is changed within the range that can be taken as the original phase difference P. .
The phase difference is changed by a phase difference changing section 1322a in the angle measurement function section 1322 changing the value of the phase difference within a predetermined phase difference changing range.
The phase difference change range can be determined by calculating a variation value from the stability of phase detection of the angle measurement function unit 1322 in the first fixed device 10A, or by experimenting by using the terminal position estimation device 1 according to the second embodiment in the usage environment. Established by specifying the

In the second embodiment, 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 changing unit 1322a is pushed back from -130° (=-175° + 45°) to -180°. The range is from +180° to +140° (=-175°-45°).
In this case, folding does not occur in the range of -130° to -180°. The range from +180° to +140° corresponds to after folding.

Therefore, after turning back, 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 shown in FIG. 10 by white circles.
Therefore, the phase difference changing unit 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 using 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 angle of arrival θ with a reduced error from the true angle of arrival θ.
Note that -180° and +180° are synonymous, but for the sake of explanation, -180° is slightly larger than -180° (-179° side), and -180° is slightly smaller than +180° (+179°). ° side) is written as +180°.

The estimated position output unit 1323 outputs -77°, which corresponds to the phase difference P obtained by the angle measurement function unit 1322 of -175°, and +90°, which corresponds to the +180° phase difference added by the phase difference changing unit 1322a. With the estimated distance information obtained by the ranging function unit 1321 using both as estimated angles of arrival θ, estimated position information indicating the estimated position of the terminal is obtained and output to the terminal position estimating unit 30.
The terminal position estimating unit 30 is the same as the terminal position estimating unit 30 in the terminal position estimating device 1 according to the first embodiment, so a description thereof will be omitted.

Note that the second fixed device 10B may also have a phase difference changing section 1322a added to the angle measurement function section 1322, similar to the first fixed device 10A.
In all of the plurality of fixed devices 10, a phase difference changing section 1322a may be added to the angle measurement function section 1322, similar to the first fixed device 10A.

As described above, the terminal position estimating device 1 according to the second embodiment has the angle measurement function of the fixed device 10, which adjusts the phase difference P in the phase difference change range with respect to the phase difference P of the received signal by radio waves from the terminal 20. It has a phase difference change function that changes the value, and when the phase difference exceeds +180° or falls below -180° in the phase difference change range, the amount of change in the phase difference is the smallest. Since the arrival angle corresponding to the phase difference is added as the estimated arrival angle, even if an error occurs in the phase difference of the received signal due to the arriving wave from the terminal 20 received by the plurality of antennas 11 and 12 of the fixed device 10. Even so, the location of the terminal 20 can be estimated with higher accuracy.

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

It suffices if at least one of the plurality of fixed devices 10 is the angle measurement function section 1322-1, but in the following explanation, the plurality of fixed devices 10 will be explained as the angle measurement function section 1322-1. do.
Note that in FIGS. 11 and 12, the same reference numerals as those shown in FIGS. 1 to 8 indicate the same or equivalent parts.

FIG. 12 is a diagram showing the relationship between the phase difference P and the angle of arrival θ.
As an example is shown by the solid line T1 in FIG. 12, the phase difference P between the received signal from the first antenna 11 and the received signal from the second antenna 12 and the arrival angle θ of the radio wave from the terminal 20 In the relationship, the phase difference P is more than +180° or less than -180° and folds back, and there are multiple angles of arrival corresponding to the phase difference P.

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

Note that 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 a value exceeding 1/2 of the wavelength λ of the radio wave from the terminal 20. Bye. When the arrangement interval d is set to a value exceeding 1/2 of the wavelength λ, the phase difference P is folded in relation to the arrival angle θ, and a plurality of arrival angles θ corresponding to the phase difference P exist.
Furthermore, even if the arrangement interval d is 1/2 or less of λ, the phase difference P may be folded back in relation to the arrival angle θ due to electromagnetic coupling between the first antenna 11 and the second antenna 12, etc. occurs, and again there are multiple angles of arrival corresponding to the phase difference P.

Below, while the terminal position estimating device 1 according to the first embodiment has an arrangement interval d between the first antenna 11 and the second antenna 12 of 0.5λ, the terminal position estimation apparatus 1 according to the third embodiment An example will be explained in which the estimation device 1 has an arrangement interval d of 0.75λ.
Since the arrangement interval d is different from that of the terminal position estimating device 1 according to the first embodiment, the operation of the angle measuring function unit 1322-1 in the fixed device 10 is the same as that of the angle measuring function unit in the terminal position estimating device 1 according to the first embodiment. Although the operation is mainly different from that of the angle measurement function section 1322-1, other points are the same, so the explanation will focus on the angle measurement function section 1322-1.

The angle measurement function section 1322-1 of the received signal processing section 132 in the transmitting/receiving section 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 second antenna 12. The phase difference P between the received signal and the received signal is determined, and the arrival angle θ is estimated from the determined phase difference P, thereby obtaining estimated arrival angle information of the arriving wave from the antenna 21 of the terminal 20.

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

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

Next, the operation of the angle measurement function section 1322-1 will be explained using an example.
Now, it is assumed that the arrival angle θ of the arriving 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 received signal from the first antenna 11 and the received signal from the second antenna 12 is ideally calculated as shown by the black circle in FIG. -135°.

Assume that the phase difference P between the received signal from the first antenna 11 and the received signal from the second antenna 12 obtained by the angle measurement function unit 1322-1 is ideally 135°.
When the phase difference P is 135°, the angle measurement function unit 1322-1 sets -30° and 57° as the estimated angle of arrival θ using the above equation (5). In FIG. 12, two estimated angles of arrival θ are obtained: −30° indicated by a black circle and 57° indicated by an arrow.

In this way, in the relationship between the phase difference P and the angle of arrival θ, if the phase difference P exceeds +180° or returns below -180°, as can be understood from FIG. There is little change in the angle of arrival θ relative to the angle of arrival, and the accuracy of angle measurement is improved.

Furthermore, 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 pieces of estimated arrival angle information corresponding to each of the plurality of arrival angles θ.
Then, the estimated position output unit 1323 indicates the estimated position of the terminal based on the estimated distance information obtained by the ranging function unit 1321 and the plurality of estimated arrival angle information obtained by the angle measurement function unit 1322-1. A plurality of pieces of estimated position information are obtained and output to the terminal position estimation section 30.

As a result, even if there are a plurality of angles of arrival θ corresponding to the phase difference P, the terminal position estimation unit 30 can obtain a probable estimated position of the terminal.
The terminal position estimating unit 30 is the same as the terminal position estimating unit 30 in the terminal position estimating device 1 according to the first embodiment, so a description thereof will be omitted.

As described above, in the terminal position estimating device 1 according to the third embodiment, the angle measurement function unit 1322-1 determines whether the phase difference P exceeds +180° or -180° in the relationship between the phase difference P and the angle of arrival θ. When receiving a received signal from the first antenna 11 and a received signal from the second antenna 12, which have a relationship of being aliased below the Estimated angle of arrival information with improved angle accuracy is obtained, and if there are multiple angles of arrival θ corresponding to the phase difference P, multiple pieces of estimated angle of arrival information corresponding to each of the plurality of angles of arrival θ are obtained, so the position of the terminal 20 can be determined. It can be estimated with higher accuracy.

Embodiment 4.
A terminal position estimating device 1 according to Embodiment 4 will be described with reference to FIGS. 13 and 14.
The terminal position estimating device 1 according to the fourth embodiment has an angle measurement function unit 1322-1 in at least one fixed device 10 among the plurality of fixed devices 10 compared to the terminal position estimating device 1 according to the third embodiment. The difference is that a function of changing the phase difference, that is, 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 estimating device 1 according to the fourth embodiment, when the plurality of fixed devices 10 shown as one example are the first fixed device 10A and the second fixed device 10B, the first fixed device A phase difference changing section 1322a is added to the angle measurement function section 1322-1 in 10A.
The second fixed device 10B is the same as the second fixed device 10B in the terminal position estimating device 1 according to the third embodiment.
The second fixed device 10B may also have a function of changing the phase difference, that is, a phase difference changing section 1322a added to the angle measurement function section 1322-1, like the first fixed device 10A.
Note that in FIGS. 13 and 14, the same reference numerals as those shown in FIGS. 11 and 12 indicate the same or corresponding parts.

FIG. 14 is a diagram showing the relationship between the phase difference P and the angle of arrival θ.
As an example is shown by the solid line T1 in FIG. 14, the phase difference P between the received signal from the first antenna 11 and the received signal from the second antenna 12 and the arrival angle θ of the radio wave from the terminal 20 In this relationship, the phase difference P exceeds +180° or falls back below −180°, and there are a plurality of arrival angles θ corresponding to the phase difference P.

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

The terminal position estimating device 1 according to the fourth embodiment will be described using an example in which the arrangement interval d is 0.75λ.
In the first fixed device 10A, the angle measurement function section 1322-1 of the received signal processing section 132 in the transmitting/receiving section 13A receives the return wave from the antenna 21 of the terminal 20 as an incoming wave from the first antenna 11A. Determine the phase difference P between the signal and the received signal from the second antenna 12A, estimate the arrival angle θ from the determined phase difference P, and obtain estimated arrival angle information of the arriving 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, which are input to the angle measurement function unit 1322-1, are determined by the phase difference P between the two received signals and the arrival of radio waves from the terminal 20. Regarding the angle θ, if the phase difference P exceeds +180° or is folded back below −180°, for any phase difference P, there are a plurality of arrival angles θ corresponding to the phase difference P.

When the angle-of-arrival function unit 1322-1 determines a plurality of angles of arrival θ calculated from the above equation (5) for the phase difference P, it obtains a plurality of pieces of estimated angle of arrival information corresponding to each of the plurality of angles of arrival 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 angle of arrival θ. On the other hand, if there is an arrival angle θ after turning, the phase difference changing unit 1322a is provided to change 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 is provided. , and the arrival angle corresponding to the phase difference after the phase difference change and after aliasing when the amount of change in the phase difference is the smallest, corresponding to the phase difference changed in the phase difference change range, is added. Obtained as estimated arrival angle information.

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

Next, the operation of the angle measurement function section 1322-1 will be explained using an example.
Now, it is assumed that the arrival angle θ of the arriving 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 received signal from the first antenna 11A and the received signal from the second antenna 12A is ideal as shown by the star in FIG. -127°. The phase difference P of −127° with respect to 60° where the arrival angle θ is larger than 42° is aliased.
That is, the arrival angle θ of 60° is the arrival angle after turning in the relationship between the phase difference P and the arrival angle θ.

Adding the error factor to 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 1322-1 is - Assume that the angle is 80°. In FIG. 14, the position where the phase difference P is −80° is indicated by a black circle.
When the phase difference P is −80°, the angle measurement function unit 1322-1 sets the estimated angle of arrival θ to −17° using the above equation (5).

In other words, the arrival angle θ of -17° for the phase difference P of -80° is the value before turning back from the ideal phase difference of -127° for the arrival angle θ of 60°, and the obtained phase difference P Because no aliasing occurs, the angle measurement function unit 1322-1 obtains an estimated angle of arrival θ that is different from the true angle of arrival θ.

In this way, if there is no aliasing 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. That is, assuming that there is an arrival angle after aliasing with respect to the phase difference P obtained from the received signal, 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 a phase difference changing section 1322a in the angle measurement function section 1322 changing the value of the phase difference within a predetermined phase difference changing range.
The phase difference change range can be determined by calculating a variation value from the stability of the phase detection of the angle measurement function unit 1322 in the first fixed device 10A, or by experimenting by using the terminal position estimation device 1 according to the fourth embodiment in the usage environment. Established by specifying the

In the fourth embodiment, the phase difference change range is set to ±45°.
Therefore, if the phase difference P obtained by the angle measurement function unit 1322-1 is -80°, the range of phase difference change performed by the phase difference changing unit 1322a is from -35° (=-80° + 45°). The range is -125° (=-80°-45°).
No folding occurs in the range from -35° to -125°.

On the other hand, the relationship between the phase difference P and the angle of arrival θ turns around after the angle of arrival θ is +42°. From the obtained phase difference P, the relationship between the phase difference after aliasing and the angle of arrival can be obtained with the smallest amount of change in the phase difference if the amount of change in the phase difference is -10° and the phase difference P is - This is the case of 90°. This is shown by the white circle in the figure.
Therefore, the phase difference changing unit 1322a adds −90° as the phase difference P.
The angle measurement function unit 1322-1 calculates the value obtained from equation (5) above for the estimated arrival angle θ of -17° and the phase difference P of -90°, and the arrival angle shown by the arrow in FIG. θ is added as the estimated arrival angle θ of +90°.

The added arrival angle θ of +90° uses the relationship between the phase difference P after aliasing 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 from the true arrival angle θ of 60°.

The estimated position output unit 1323 corresponds to -17°, which corresponds to the phase difference P obtained by the angle measurement function unit 1322-1 of -80°, and the phase difference of -90°, which is added by the phase difference changing unit 1322a. Based on the estimated angle of arrival information and the estimated distance information obtained by the ranging function unit 1321, both of which are set to +90° as the angle of arrival θ, estimated position information indicating the estimated position of the terminal is obtained and output to the terminal position estimating unit 30. do.
The terminal position estimating unit 30 is the same as the terminal position estimating unit 30 in the terminal position estimating device 1 according to the third embodiment, that is, the terminal position estimating unit 1 according to the first embodiment, so a description thereof will be omitted.

Note that in the relationship between the phase difference P and the angle of arrival θ, if there are multiple angles of arrival corresponding to the obtained phase difference P, the angle measurement function unit 1322-1 performs the terminal position estimation according to the third embodiment. Similar to the angle measurement function unit 1322-1 in the device 1, a plurality of pieces of estimated arrival angle information are obtained corresponding to each of the plurality of arrival angles θ corresponding to the obtained phase difference P.

As described above, in the terminal position estimating device 1 according to the fourth embodiment, the angle measurement function unit 1322-1 determines whether the phase difference P exceeds +180° or -180° in the relationship between the phase difference P and the angle of arrival θ. When receiving a received signal from the first antenna 11 and a received signal from the second antenna 12, which have a relationship of being aliased below the Estimated angle of arrival information with improved angle accuracy is obtained, and if there are multiple angles of arrival θ corresponding to the phase difference P, multiple pieces of estimated angle of arrival information corresponding to each of the plurality of angles of arrival θ are obtained, so the position of the terminal 20 can be determined. It can be estimated with higher accuracy.

Further, in the relationship between the phase difference P and the angle of arrival θ, assuming that there is an angle of arrival after aliasing with respect to the phase difference P of the obtained received signal, corresponding to the phase difference changed in the phase difference change range, Since the arrival angle that corresponds to the phase difference after the change in phase difference and after turning back when the amount of change in the phase difference is the smallest is added as the estimated arrival angle, for example, the multiple antennas 11 of the fixed device 10, Even if there is an error in the phase difference of the received signal due to the arriving 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 estimating device 1 according to Embodiment 5 will be described with reference to FIGS. 15 and 16.
In the terminal position estimating device 1 according to the fifth embodiment, each of the plurality of fixed devices 10 in the terminal position estimating device 1 according to the first embodiment has a ranging function and an angle measuring function, and indicates the estimated position of the terminal. The difference is that at least one of the plurality of fixed devices 10 does not have an angle measurement function and obtains estimated distance information using a ranging function, whereas the plurality of fixed devices 10 obtains estimated position information. 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 estimating device 1 according to the fifth embodiment divides the plurality of fixed devices 10 into a first G and a second G, and the first G fixed device 10 has a ranging function and an angle measuring function. The second G fixed device 10 obtains estimated distance information using a ranging function.
It is preferable to have a plurality of first G fixing devices 10, and may be one, and the second G fixing device 10 may be one or more.

The terminal position estimating device 1 according to the fifth embodiment has a plurality of fixed devices 10, which are shown as an example, in the terminal position estimating device 1 according to the first embodiment, and a first fixed device 10A and a second fixed device 10A. In the case of a fixed device 10B, the first fixed device 10A is the same as the fixed device 10 in the terminal position estimating device 1 according to the first embodiment, and the second fixed device 10B has an angle measurement function in the received signal processing section 132. does not have.

Therefore, the received signal processing section 132B and the terminal position estimating section 30 in the second fixed device 10B will be mainly explained. Description of the first fixing device 10A will be omitted.
Note that in FIGS. 15 and 16, the same reference numerals as those shown in FIGS. 1 to 8 indicate the same or equivalent parts.

The second fixing device 10B will be explained below.
As shown in FIG. 16, the second fixed device 10B includes a transmitting/receiving antenna 11B and a transmitting/receiving section 13B.
The transmitting/receiving section 13B includes a receiving signal processing section 132B that includes a transmitting signal processing section 131B that outputs a transmitting signal to the transmitting/receiving antenna 11B, and a ranging function section 1321B that processes the received signal from the transmitting/receiving antenna 11B and outputs estimated distance information. Equipped with
The transmitting/receiving antenna 11B receives the transmitting signal from the transmitting signal processing unit 131, radiates a transmitting wave made of radio waves into space, receives a reply wave from the antenna 21 of the terminal 20 as an arriving wave, and generates a received signal based on the arriving wave. Output.

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

The terminal position estimating unit 30 includes an estimated position indicated by each of the plurality of pieces of estimated position information in the first fixed device 10A, and a second point indicated by the estimated distance information in the second fixed device 10B, each of which corresponds to a plurality of pieces of estimated position information. The shortest distance between the combined estimated position and the estimated position on the circumference is determined by combining the estimated position on the circumference centered on the fixed device 10B, and the first Estimated position information on the fixed device 10A is obtained, and the obtained estimated position information is output to the display 40.

In the example shown in FIG. 15, the terminal position estimating unit 30 estimates the estimated position PA1 indicated by the estimated position information of the first fixed device 10A, the estimated position PA1 indicated by the estimated distance information of the second fixed device 10B, and the second The shortest distance d1 between the estimated position on the circumference in the plane containing the antenna 11B of the fixed device 10B, and the estimated position PA2 indicated by the estimated position information on the first fixed device 10A, and the second fixed device 10B. The shortest distance d2 between the estimated position PA2 indicated by the estimated distance information at is selected as a likely position for the terminal 20.

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

Note that the terminal position estimating unit 30 includes the position information indicated by the estimated position information of the first fixed device 10A where the shortest distance is the minimum and the antenna 11B of the second fixed device 10B as position information indicating a likely position. Estimated position information indicating an intermediate position between the estimated positions on the circumference of the plane may be output to the display 40.

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

In the first fixed device 10A, similarly to the first fixed device 10A shown in the third embodiment, the angle measurement function unit 1322 determines that the phase difference P is +180° in the relationship between the phase difference P and the angle of arrival θ. When receiving a received signal from the first antenna 11 and a received signal from the second antenna 12, which are in a relationship that exceeds or returns below -180°, the angle of arrival θ corresponding to the phase difference P is one. If so, estimated angle of arrival information with improved angle measurement accuracy is obtained, and if there are multiple angles of arrival θ corresponding to the phase difference P, multiple pieces of estimated angle of arrival information corresponding to each of the plurality of angles of arrival θ are obtained. do.

In the first fixed device 10A, similarly to the first fixed device 10A shown in Embodiment 4, the angle measurement function section 1322 detects the angle of arrival from the first antenna 11A in the relationship between the phase difference P and the angle of arrival θ. If there is an arrival angle θ after aliasing 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 is determined for the obtained phase difference P. In other words, when the phase difference changing unit 1322a is provided with a phase difference changing function and the amount of change in the phase difference corresponding to the phase difference changed in the phase difference changing range is the smallest. It is assumed that the angle of arrival corresponding to the phase difference after the change in the phase difference and after the aliasing is obtained as additional estimated angle of arrival information.

As described above, the terminal position estimating device 1 according to the fifth embodiment has an estimated position indicated by each of a plurality of pieces of estimated position information in the first fixed device 10A, and a second and the estimated position on the circumference centered on the second fixed device 10B indicated by the estimated distance information on the fixed device 10B, and find 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 where the shortest distance obtained is the minimum and the estimated position on the circumference as the combination's estimated position information, for example, the first fixed device 10A Even if an error occurs in the phase difference P of the received signals due to the arriving 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 wireless device according to Embodiment 6 will be described with reference to FIGS. 17 and 18.
A vehicle wireless communication system, which is a keyless system for a vehicle, includes a vehicle wireless device and a terminal 20.
The vehicle wireless device according to the sixth embodiment corresponds to any of the terminal position estimation devices 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 transmitting/receiving section 22.

A plurality of vehicle wireless devices are installed inside the cabin 101 of the vehicle 100, for example, four communication devices mounted near the four sides of the cabin 101, that is, the left side, the right side, the front side, and the rear side. The vehicle 100 includes fixed devices 10A to 10D, and a terminal position estimating unit 30 mounted in the vehicle 100.
Fixture machines 10A to 10D correspond to any of the fixation machines 10 shown in Embodiments 1 to 5.

The first fixing device 10A is arranged near the left side inside the vehicle interior 101, the second fixing device 10B is arranged near the right side inside the vehicle interior 101, and the third fixing device 10C is located inside the vehicle interior 101. The fourth fixing device 10D is arranged near the front side, and the fourth fixing device 10D is arranged near the rear side inside the vehicle compartment 101.
The first antennas 11A to 11D and the second antennas 12A to 12D of the first fixed device 10A to the fourth fixed device 10D are vertically installed.

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 interior 101 in 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 passenger compartment 101, and the arrangement direction of the first antenna 11B and the second antenna 12B is perpendicular to the left side of the passenger compartment 101. The direction in which the first antenna 11C and the second antenna 12C are arranged is 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 in the direction perpendicular to the right side of the vehicle. The direction is 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 perpendicular to the side of the vehicle interior 101 on the horizontal plane, so that By obtaining the angle of arrival θ with respect to the terminal 20, each terminal 10D can determine whether the terminal 20 exists within the vehicle interior 101 or outside the vehicle interior 101.

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

As shown in FIG. 18, the first fixing machine 10A to the fourth fixing machine 10D have the same configuration as any of the first fixing machines 10A shown in Embodiments 1 to 4.
Further, in the first fixing machine 10A to the fourth fixing machine 10D, three fixing machines have the same configuration as the first fixing machine 10A shown in Embodiment 5, and the remaining one fixing machine has the same configuration as the first fixing machine 10A shown in the fifth embodiment. It may have the same configuration as the second fixing machine 10B.
Therefore, explanations regarding the first fixed machine 10A to the fourth fixed machine 10D will be omitted.

As shown in FIG. 18, the terminal position estimation section 30 includes an input interface 31, a storage section 32, a point-to-point distance calculation section 33, a selection section 34, and an output interface 35.
The terminal position estimating unit 30 is composed of a CPU, a RAM, and a ROM, and the 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 process shown is executed. The terminal position estimation unit 30 is driven by a general-purpose OS.
Note that the received signal processing sections 132 in the first to fourth fixed devices 10A to 10D may also be incorporated together with the terminal position estimating section 30 into hardware configured by a CPU, RAM, and ROM.

Terminal position estimating section 30 operates similarly to terminal position estimating section 30 shown in Embodiments 1 to 5.
That is, the terminal position estimation unit 30 receives 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. Receiving the position information and a plurality of estimated position information from the fourth fixed device 10D, combining each estimated position information of each fixed device 10 with each other, and calculating the distance or shortest distance between the estimated positions indicated by the combined estimated position information. , and obtain the estimated position information of the combination that minimizes the calculated distance.

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 distance between the first fixed device The distance between the estimated position indicated by each of the plurality of estimated position information from the fourth fixed device 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 of the plurality of estimated position information from the third fixed device 10C, and the estimated position indicated by each of the plurality of estimated position information from the second fixed device 10B and the fourth The distance between the estimated position indicated by each of the plurality of estimated position information from the third fixed aircraft 10D, and the distance between the estimated position indicated by each of the plurality of estimated position information from the third fixed aircraft 10C and the fourth fixed aircraft 10D. The distance between the estimated positions indicated by each of the plural pieces of estimated position information is calculated, and the calculated result is linked to each of the estimated position information from the two fixed devices 10 and output to the storage unit 32 as combined estimated position information.

The selection unit 34 reads out the plurality of combined estimated position information stored in the storage unit 32, obtains the combined estimated position information with the minimum distance information in the combined estimated position information, and selects the first combination estimated position information based on the minimum combined estimated position information. A combination of estimated position information including estimated position information by the second fixed device 10A, estimated position information by the second fixed device 10B, and distance information between them is output to the display 40 via the output interface 35.

Note that the terminal position estimation unit 30 combines each estimated position information from the first fixed device 10A to the fourth fixed device 10D, and calculates the distance or shortest distance between the estimated positions indicated by the combined estimated position information. , the estimated position information of the combination that minimizes the calculated distance has been obtained, but the estimated position information from two or three fixed devices 10 among the first fixed device 10A to the fourth fixed device 10D is obtained. The estimated position information of the combination may be obtained using the above method.
When selecting two or three fixed devices 10, it is preferable to select the fixed devices 10 whose received signal power is higher in order.

As described above, the vehicle wireless device according to the sixth embodiment can accurately determine the position of the terminal 20, which is a keyless portable device of the keyless system, as is clear from the descriptions of the first to fifth embodiments. It can be estimated.

Note that it is possible to freely combine each embodiment, to modify any component of each embodiment, or to omit any component in each embodiment.

The terminal position estimating device according to the present disclosure is applied to a device that estimates 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 preferable.

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

Claims (26)

Comprising a plurality of fixed devices placed at different positions and a terminal position estimator,
Each of the plurality of fixed devices has a ranging function that estimates the distance to the terminal, and determines the arrival angle of the radio wave from the terminal based on the phase difference of the received signal of radio waves from the terminal received using a plurality of antennas. has an angle measurement function to estimate, and obtains estimated position information indicating the estimated position of the terminal based on the distance estimated by the distance measurement function and the angle of arrival estimated by the angle measurement function,
At least one of the plurality of fixed devices performs a plurality of different estimates indicating the estimated position of the terminal based on each of a plurality of distances estimated by the distance measurement function and angles of arrival estimated by the angle measurement function. Get location information,
The terminal position estimating unit combines the estimated position information of the plurality of fixed devices located at different positions, calculates the distance between the estimated positions indicated by the combined estimated position information, and determines the distance between the estimated positions indicated by the combined estimated position information, and determines the distance between the estimated positions indicated by the combined estimated position information. Obtain the estimated position information of the combination,
Terminal position estimation device. The terminal position estimating device according to claim 1, wherein the terminal position estimating unit outputs estimated position information of a combination that minimizes a distance between estimated positions. The terminal position estimating device according to claim 1, wherein the terminal position estimating unit outputs estimated position information indicating an intermediate position between two estimated positions indicated by a combination of estimated position information with a minimum distance between the estimated positions. . The terminal position estimation unit according to claim 1, wherein the terminal position estimating unit outputs one of the estimated position information selected based on a selection criterion among the combination of estimated position information that minimizes the distance between the estimated positions. Estimation device. The angle measurement function of at least one of the plurality of fixed devices is a phase difference changing function that changes the value of the phase difference within a phase difference changing range with respect to the phase difference of the received signal by radio waves from the terminal. and the angle of arrival 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. The terminal position estimating device according to any one of claims 1 to 4, wherein the terminal position estimating device adds as the estimated angle of arrival. 6. The terminal position estimating device according to claim 1, wherein the distance between adjacent antennas in each of the plurality of fixed devices is half the wavelength of radio waves from the terminal. The terminal position according to claim 6, wherein the plurality of estimated angles of arrival at at least one of the plurality of fixed devices are angles of arrival estimated multiple times within a set measurement time by the angle measurement function. Estimation device. The plurality of estimated angles of arrival at at least one of the plurality of fixed devices are determined by the phase difference between the received signal due to radio waves from the terminal received using the plurality of antennas and the radio waves from the terminal. When the phase difference exceeds +180° or falls below -180°, the relationship between the angle of arrival of The terminal position estimating device according to any one of claims 1 to 5, which is an angle. The plurality of estimated angles of arrival at at least one of the plurality of fixed devices are determined by the phase difference between the received signal due to radio waves from the terminal received using the plurality of antennas and the radio waves from the terminal. When the phase difference exceeds +180° or falls below -180°, the relationship between the angle of arrival of is an angle,
The angle measurement function of at least one of the plurality of fixed devices is a phase difference changing function that changes the value of the phase difference within a phase difference changing range with respect to the phase difference of the received signal by radio waves from the terminal. have
In the relationship between the phase difference and the arrival angle, assuming that there is an arrival angle after aliasing 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. The terminal position according to any one of claims 1 to 4, wherein the arrival angle corresponding to the phase difference after the change in phase difference when the amount is the smallest and after aliasing is added as the estimated arrival angle. Estimation device. Any one of claims 1 to 5, 8, and 9, wherein the distance between adjacent antennas in each of the plurality of fixed devices is a value exceeding 1/2 of the wavelength of the radio wave from the terminal. Terminal position estimation device according to item 1. It has a distance measurement function that estimates the distance to the terminal, and an angle measurement function that estimates the arrival angle of the radio waves from the terminal based on the phase difference of the received signal of radio waves from the terminal received using multiple antennas. , a first fixed device that obtains a plurality of estimated position information indicating the estimated position of the terminal based on the estimated distance and each of the plurality of estimated angles of arrival;
a second fixed device that is disposed at a different location from the first fixed device, has a ranging function for estimating the distance to the terminal, and obtains the estimated distance as estimated distance information;
an estimated position indicated by each of a plurality of pieces of estimated position information on the first fixed device, and an estimated position corresponding to a plurality of pieces of estimated position information, and centered around the second fixed device indicated by estimated distance information on 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 then combine the estimated position on the circumference with the combination where the shortest distance obtained is the minimum. a terminal position estimation unit that obtains the estimated position of the combination as estimated position information;
A terminal position estimation device equipped with 12. The terminal position estimating device according to claim 11, wherein the terminal position estimating unit outputs estimated position information on the first fixed device in a combination of estimated position information that minimizes the determined shortest distance. The terminal position estimating unit is configured to calculate a circle 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 determined shortest distance. The terminal position estimating device according to claim 11, which outputs estimated position information indicating an intermediate position between estimated positions on the circumference. The angle measurement function in the first fixed device includes a phase difference changing function that changes the value of the phase difference within a phase difference changing range with respect to the phase difference of the received signal by radio waves from the terminal, and When the phase difference exceeds +180° or falls below -180° in the range and turns back, 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 is added as the estimated arrival angle. The terminal position estimating device according to any one of claims 11 to 13. 15. The terminal position estimating device according to claim 11, wherein the distance between adjacent antennas in the first fixed device is half the wavelength of radio waves from the terminal. 16. The terminal position estimating device according to claim 15, wherein the plurality of estimated angles of arrival at the first fixed device are angles of arrival estimated multiple times within a set measurement time by the angle measurement function. The plurality of estimated angles of arrival at the first fixed device are based on the relationship between the phase difference of the received signal of radio waves from the terminal received using the plurality of antennas and the angle of arrival of the radio waves from the terminal. The angle of arrival is estimated based on the existence of a plurality of the angles of arrival corresponding to the phase difference when the phase difference exceeds +180° or falls below -180°. The terminal position estimating device according to any one of Item 14. The plurality of estimated angles of arrival at the first fixed device are based on the relationship between the phase difference of the received signal of radio waves from the terminal received using the plurality of antennas and the angle of arrival of the radio waves from the terminal. The phase difference is greater than +180° or less than -180° and turns back, and for any phase difference, the angle of arrival is estimated based on the existence of a plurality of the angles of arrival corresponding to the phase difference,
The angle measurement function in the first fixed device has a phase difference changing function that changes the value of the phase difference in a phase difference changing range with respect to the phase difference of the received signal by radio waves from the terminal,
In the relationship between the phase difference and the arrival angle, assuming that there is an arrival angle after aliasing 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. The terminal position according to any one of claims 11 to 13, wherein an angle of arrival corresponding to a phase difference after a change in phase difference when the amount is the smallest and which corresponds to a phase difference after aliasing is added as the estimated angle of arrival. Estimation device. Any one of claims 11 to 14, 17, and 18, wherein the distance between adjacent antennas in the first fixed device is a value exceeding 1/2 of the wavelength of the radio wave from the terminal. Terminal position estimating device according to section. a ranging step in which each of the plurality of fixed devices placed at different positions estimates the distance to the terminal;
an angle measuring step in which each of the plurality of fixed devices estimates the arrival angle of the radio wave from the terminal based on the phase difference of a received signal of radio waves from the terminal received using a plurality of antennas;
a position estimating step in which each of the plurality of fixed devices obtains estimated position information indicating the estimated position of the terminal based on the estimated distance and the estimated angle of arrival;
At least one of the plurality of fixed devices obtains a plurality of estimated position information indicating the estimated position of the terminal based on each of the estimated distance and the estimated angle of arrival, and a terminal position estimation unit is to combine the estimated position information of the plurality of fixed devices placed at different positions, calculate the distance between the estimated positions indicated by the combined estimated position information, and estimate the combination that minimizes the calculated distance. a combined position estimation step for obtaining position information;
A device position estimation method with The angle measurement step is performed 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 due to radio waves from the terminal. 21. The terminal position estimating method according to claim 20, further comprising the step of estimating an arrival angle corresponding to a phase difference after the phase difference has changed when the amount of change in the phase difference is the smallest. In the angle measuring step, the relationship between the phase difference of the received signal due to the radio waves from the terminal and the arrival angle of the radio waves from the terminal is such that the phase difference exceeds +180° or falls back below -180°, and either 21. The terminal position estimating method according to claim 20, further comprising the step of estimating the angle of arrival based on the presence of a plurality of the angles of arrival corresponding to the phase difference. In the angle measuring step, the relationship between the phase difference of the received signal due to the radio waves from the terminal and the arrival angle of the radio waves from the terminal is such that the phase difference exceeds +180° or falls back below -180°, and either With a phase difference of
In the relationship between the phase difference and the arrival angle, assuming that there is an arrival angle after aliasing 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 estimating method according to claim 20, further comprising the step of estimating an arrival angle that is obtained by estimating an arrival angle that corresponds to a phase difference after a change in phase difference when is the smallest and that corresponds to a phase difference after aliasing. a distance measuring step in which the first fixed device estimates the distance to the terminal;
an angle measuring step in which the first fixed device estimates a plurality of arrival angles of radio waves from the terminal based on phase differences of received signals of radio waves from the terminal received using a plurality of antennas;
a position estimating step in which the first fixed device obtains a plurality of pieces of estimated position information indicating the estimated position of the terminal based on the estimated distance and each of the plurality of estimated angles of arrival;
a distance measuring step in which the second fixed device estimates the distance to the terminal;
The terminal position estimating unit includes an estimated position indicated by each of the plurality of pieces of estimated position information on the first fixed device, and an estimated position corresponding to the plurality of pieces of estimated position information, and the estimated position indicated by the estimated distance information on the second fixed device. Combine the estimated positions on the circumference centered on the fixed machine in 2, find the shortest distance between the combined estimated position and the estimated position on the circumference, and find 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 device position estimation method with A vehicle wireless device that performs wireless communication with a keyless portable device as a terminal ,
comprising a plurality of communication devices installed inside a vehicle interior of a vehicle, and a terminal position estimating unit installed inside the vehicle,
The plurality of communication devices are constituted by a plurality of fixed devices in the terminal position estimating device according to any one of claims 1 to 10 ,
The terminal position estimating unit combines a plurality of pieces of estimated position information of the plurality of communication devices, calculates a distance between estimated positions indicated by the combined estimated position information, and estimates a combination that minimizes the calculated distance. Vehicle radio equipment that obtains location information. A vehicle wireless device that performs wireless communication with a keyless portable device as a terminal ,
comprising a plurality of communication devices installed inside a vehicle interior of a vehicle, and a terminal position estimating unit installed inside the vehicle,
The plurality of communication devices are configured by a first fixed device and a second fixed device in the terminal position estimating device according to any one of claims 11 to 19 ,
The terminal position estimating unit includes:
an estimated position indicated by each of a plurality of pieces of estimated position information on the first fixed device , and an estimated position corresponding to a plurality of pieces of estimated position information, and centered around the second fixed device indicated by estimated distance information on 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 then combine the estimated position on the circumference with the combination where the shortest distance obtained is the minimum. A vehicle wireless device that obtains the estimated position of the vehicle as combined estimated position information.

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