Position estimation device, position estimation method, and position estimation program

Abstract

To provide a position estimation device that estimates from one mobile body the position of another mobile body.SOLUTION: A position estimation device includes beam control means for controlling the directivity of a plurality of transmitting antennas, transmitting means for transmitting a pilot signal to a receiver, and receiving means for receiving an estimated position estimated by the receiver from the receiver. When the transmitting means transmits the pilot signal to the receiver, the beam control means controls the directivity of the plurality of transmitting antennas so that the plurality of transmitting antennas have a first directivity, and based on the estimated position, the beam control means controls the directivity of the plurality of transmitting antennas so that the plurality of transmitting antennas have a second directivity, where the second directivity is steeper than the first directivity.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present disclosure relates to a position estimation device, a position estimation method, and a position estimation program. [Background technology]

[0002] Patent Document 1 describes a position estimation device that estimates the position of a mobile object from a base station of a wireless communication system. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2022 / 244193 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the position estimation device described in Patent Document 1 has a problem in that the accuracy of position estimation deteriorates unless the position of the antenna of the base station is fixed.

[0005] The present disclosure aims to provide a position estimation device that solves the above-mentioned problems. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, there is provided a position estimation device comprising: a beam control means for controlling the directivity of a plurality of transmitting antennas; a transmitting means for transmitting a pilot signal to a receiver; and a receiving means for receiving from the receiver an estimated position estimated by the receiver, wherein when the transmitting means transmits the pilot signal to the receiver, the beam control means controls the directivity of the plurality of transmitting antennas so that the plurality of transmitting antennas have a first directivity, and based on the estimated position, the beam control means controls the directivity of the plurality of transmitting antennas so that the plurality of transmitting antennas have a second directivity, the second directivity being steeper than the first directivity.

[0007] According to one aspect of the present disclosure, there is provided a position estimation method comprising: a beam control step of controlling directivities of a plurality of transmitting antennas; a transmitting step of transmitting a pilot signal to a receiver; and a receiving step of receiving an estimated position estimated by the receiver from the receiver, wherein when the transmitting step transmits the pilot signal to the receiver, the beam control step controls the directivities of the plurality of transmitting antennas so that the plurality of transmitting antennas have a first directivity, and based on the estimated position, the beam control step controls the directivities of the plurality of transmitting antennas so that the plurality of transmitting antennas have a second directivity, the second directivity being steeper than the first directivity.

[0008] According to one aspect of the present disclosure, there is provided a position estimation program comprising: a beam control step of controlling directivities of multiple transmitting antennas; a transmitting step of transmitting a pilot signal to a receiver; and a receiving step of receiving an estimated position estimated by the receiver from the receiver, wherein when the transmitting step transmits the pilot signal to the receiver, the beam control step controls the directivities of the multiple transmitting antennas so that the multiple transmitting antennas have a first directivity, and based on the estimated position, the beam control step controls the directivities of the multiple transmitting antennas so that the multiple transmitting antennas have a second directivity, the second directivity being steeper than the first directivity. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide a position estimation device that estimates the position of one moving body from another moving body. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram illustrating an example of a location estimation system according to an embodiment of the present disclosure. [Figure 2] 1 is a schematic diagram illustrating an example of a communication method between two mobile objects according to an embodiment of the present disclosure. [Figure 3] 1 is a block diagram showing a configuration of a moving body according to an embodiment of the present disclosure. [Figure 4] 1 is a block diagram showing a hardware configuration of an information processing device of a mobile body according to an embodiment of the present disclosure. [Figure 5] FIG. 2 is a block diagram illustrating a configuration of a transmitting unit of a mobile body according to an embodiment of the present disclosure. [Figure 6] FIG. 2 is a block diagram illustrating a configuration of a receiving unit of a mobile body according to an embodiment of the present disclosure. [Figure 7] FIG. 1 is a schematic diagram illustrating an example of an antenna arrangement according to an embodiment of the present disclosure. [Figure 8] FIG. 2 is a schematic diagram illustrating an example of the spatial directivity of an antenna array according to an embodiment of the present disclosure. [Figure 9] FIG. 2 is a schematic diagram illustrating an example of the spatial directivity of an antenna array according to an embodiment of the present disclosure. [Figure 10] 10 is a sequence chart illustrating a position estimation process according to an embodiment of the present disclosure. [Figure 11] FIG. 2 is a schematic diagram illustrating an example of the spatial directivity of an antenna array according to an embodiment of the present disclosure. [Figure 12] FIG. 2 is a schematic diagram illustrating an example of the spatial directivity of an antenna array according to an embodiment of the present disclosure. [Figure 13]1 is a block diagram illustrating a location estimation device according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] A position estimation device according to an embodiment of the present disclosure will be described below with reference to the drawings. In all the drawings, the same or corresponding components are designated by the same reference numerals, and common descriptions will be omitted.

[0012] [First embodiment] 1 is a schematic diagram illustrating an example of a position estimation system according to an embodiment of the present disclosure. The position estimation system 1 includes at least two moving objects 2. A moving object 2 is connected to another moving object 2 so that they can communicate with each other. The moving objects 2 may be, for example, a bicycle, a motorcycle, an automobile, a train, a ship, an aircraft, an aerial drone, or the like. Alternatively, a user may carry an information processing device such as a mobile terminal and board a bicycle, a motorcycle, an automobile, a train, a ship, an aircraft, or the like. The moving objects 2 are not limited to the above examples as long as they are movable and capable of communicating with each other.

[0013] It is desirable that at least two moving bodies 2 are connected to each other so that they can communicate with each other via a wireless communication path. At least two moving bodies 2 may also be connected to each other so that they can communicate with each other via a wired communication path. For example, if the moving bodies 2 are flying drones and there are no obstacles or the like between the at least two moving bodies 2, the at least two moving bodies 2 may be connected to each other via a cable or the like and communicate with each other via a wired communication path. When the at least two moving bodies 2 communicate with each other via a wired communication path, the at least two moving bodies 2 may perform position estimation, described below, via a wireless communication path. In this disclosure, for simplicity, the present embodiment will be described assuming that the moving body 2 that transmits a signal is mobile body 2Tx and the moving body 2 that receives the signal is mobile body 2Rx. Mobile body 2Tx transmits a signal 4 to mobile body 2Rx. Mobile body 2Rx receives the signal 4 from mobile body 2Tx. It goes without saying that mobile body 2Rx can also transmit a signal 4 to mobile body 2Tx, and mobile body 2Tx can also receive the signal 4 from mobile body 2Rx.

[0014] FIG. 2 is a schematic diagram illustrating an example of a communication method between two mobile bodies according to an embodiment of the present disclosure. A mobile body 2Tx transmits a pilot signal 41 to a mobile body 2Rx. When the mobile body 2Tx transmits the pilot signal 41 to the mobile body 2Rx, the mobile body 2Tx may perform beam scanning at a predetermined angle in advance to estimate the transmission direction of the pilot signal 41 to the mobile body 2Rx. For example, if the traveling direction of the mobile body 2Tx is set to 0 degrees, the mobile body 2Tx performs beam scanning at azimuth angles from -90 degrees to +90 degrees. The mobile body 2Tx transmits a signal while performing beam scanning. The mobile body 2Tx receives reflected waves of the transmitted signal and estimates the azimuth angle at which the amplitude of the reflected waves is maximum for the azimuth angle at which the beam scanning was performed. The mobile body 2Tx can determine the estimated azimuth angle as the transmission direction of the pilot signal 41 to the mobile body 2Rx. Alternatively, the moving body 2Tx and the moving body 2Rx may estimate the positional relationship between the moving body 2Tx and the moving body 2Rx based on information from a Global Positioning System (GPS) or the like. In actual direction estimation or position estimation, the directional relationship or positional relationship between the moving body 2Tx and the moving body 2Rx may be a directional relationship or positional relationship in a three-dimensional space. For simplicity of explanation, this embodiment will be explained using the directional relationship or positional relationship between the moving body 2Tx and the moving body 2Rx as a directional relationship or positional relationship in a two-dimensional plane.

[0015] The mobile unit 2Rx receives a pilot signal 41 from the mobile unit 2Tx. The mobile unit 2Rx estimates the relative direction or relative position between the mobile unit 2Tx and the mobile unit 2Rx based on the pilot signal 41. In FIG. 2, the relative direction and relative position estimated by the mobile unit 2Rx are called "estimated positions." The mobile unit 2Rx transmits an estimated position 42 to the mobile unit 2Tx. The mobile unit 2Tx receives the estimated position 42 from the mobile unit 2Rx. The mobile unit 2Tx transmits a control signal / data signal 43 to the mobile unit 2Rx based on the estimated position 42. The mobile unit 2Rx receives the control signal / data signal 43 from the mobile unit 2Tx. In this way, data communication is performed between the mobile unit 2Tx and the mobile unit 2Rx. In addition, the estimated position may be a relative direction or relative position based on the position of the mobile body 2Tx at the time when the mobile body 2Tx transmitted the pilot signal 41 to the mobile body 2Rx, or may be a relative direction or relative position based on the position of the mobile body 2Rx at the time when the mobile body 2Rx received the pilot signal 41 from the mobile body 2Tx.

[0016] When one or both of the moving body 2Tx and the moving body 2Rx are moving at high speed, when the moving body 2Tx and the moving body 2Rx are moving in opposite directions facing each other, when one of the moving body 2Tx and the moving body 2Rx is circling the other, etc., the moving body 2Tx must transmit a pilot signal 41 to the moving body 2Rx at a transmission period shorter than the transmission period P of the pilot signal when the moving body 2Tx is not moving, and estimate the relative direction or relative position of the moving body 2Tx and the moving body 2Rx. A shorter transmission period P can shorten the time per unit time that the moving body 2Tx can transmit a control signal or data signal to the moving body 2Rx. This can reduce the throughput from the moving body 2Tx to the moving body 2Rx. Furthermore, when the mobile body 2Rx moves in a direction (e.g., elevation angle direction) perpendicular to the direction (e.g., azimuth angle direction) in which the mobile body 2Tx performs beam scanning, it is difficult for the mobile body 2Tx to estimate the transmission direction of the pilot signal 41 to the mobile body 2Rx by the beam scanning by the mobile body 2Tx.

[0017] In such a case, the position estimation system 1 of the present invention controls the directional characteristics of the transmitting antenna of the moving body 2Tx to make the directional characteristics relatively gentle when transmitting the pilot signal 41 and to make the directional characteristics relatively steep when transmitting the control signal / data signal 43. By controlling the directional characteristics of the transmitting antenna of the moving body 2Tx in accordance with the signal transmitted by the moving body 2Tx, the moving body 2Tx can transmit the pilot signal 41 and the control signal / data signal 43 without scanning the beam in multiple directions. Note that when the relative speed difference between the moving body 2Tx and the moving body 2Rx is large, the directional characteristics of the transmitting antenna of the moving body 2Tx may be made gentle when transmitting the control signal / data signal 43, similar to the directional characteristics when transmitting the pilot signal 41.

[0018] 3 is a block diagram showing the configuration of a mobile object 2 according to an embodiment of the present disclosure. The mobile object 2 includes an information processing device 21, a transmitting unit 22, and a receiving unit 23. The information processing device 21 can determine the communication method of the signal 4, etc. If the mobile object 2 is the mobile object 2Tx in FIG. 1 or FIG. 2, the information processing device 21 may generate information included in the pilot signal 41 and information included in the control signal / data signal 43. If the mobile object 2 is the mobile object 2Rx in FIG. 1 or FIG. 2, the information processing device 21 may generate information included in the estimated position 42.

[0019] When the moving body 2 is the moving body 2Tx in FIG. 1 or FIG. 2, the transmitter 22 transmits a pilot signal 41 or a control signal / data signal 43 to the moving body 2Rx. When the moving body 2 is the moving body 2Rx in FIG. 1 or FIG. 2, the transmitter 22 transmits an estimated position 42 to the moving body 2Tx. When the moving body 2 is the moving body 2Tx in FIG. 1 or FIG. 2, the receiver 23 receives the estimated position 42 from the moving body 2Rx. When the moving body 2 is the moving body 2Rx in FIG. 1 or FIG. 2, the receiver 23 receives the pilot signal 41 or the control signal / data signal 43 from the moving body 2Tx. Note that some of the functions of the transmitter 22 and the receiver 23 may be implemented using software or firmware, and the information processing device 21 may execute some of the functions of the transmitter 22 and some of the functions of the receiver 23.

[0020] FIG. 4 is a block diagram showing the hardware configuration of an information processing device 21 according to an embodiment of the present disclosure. The information processing device 21 generates information contained in a pilot signal 41, an estimated position 42, and a control signal / data signal 43. For example, in a mobile unit 2Tx, the information processing device 21 generates a bit sequence contained in the pilot signal 41 or a bit sequence contained in the control signal / data signal 43, modulates the bit sequence, and generates digital signals for each of multiple transmitting antennas. The information processing device 21 also demodulates the estimated position 42 received by each of multiple receiving antennas to obtain the relative direction or relative position between the mobile unit 2Tx and the mobile unit 2Rx estimated by the mobile unit 2Rx. In the mobile unit 2Rx, the information processing device 21 generates a bit sequence containing information about the estimated position, modulates the bit sequence, and generates digital signals for each of multiple transmitting antennas. The information processing device 21 also demodulates the pilot signal 41 or the control signal / data signal 43 received by each of multiple receiving antennas to obtain the bit sequence transmitted by the mobile unit 2Tx.

[0021] The information processing device 21 includes a CPU 211, a ROM 212, a RAM 213, a storage device 214, an input / output IF (Interface) 215, and a communication IF 216. The CPU 211, the ROM 212, the RAM 213, the storage device 214, the input / output IF 215, and the communication IF 216 are connected via a bus 219 so as to be able to communicate with each other.

[0022] The CPU 211 is a central processing unit. The CPU 211 controls each part of the information processing device 21 using an application program. The ROM 212 is a read only memory. The ROM 212 is made up of a non-volatile memory and stores an application program for controlling each part of the information processing device 21. The RAM 213 is a random access memory. The RAM 213 provides a memory area necessary for the operation of the CPU 211. The storage device 214 is a large-capacity storage device such as a hard disk drive.

[0023] The input / output IF 215 is an input / output interface that receives voice input from the user of the information processing device 21, outputs voice to the user, and transmits and receives data or information between the information processing device 21 and other devices. The input / output IF 215 may include a mouse, a touch panel, a trackball, a keyboard, earphones, headphones, a speaker, a display, etc. The user can operate the information processing device 21 via the input / output IF 215. The communication IF 216 performs mutual communication between the information processing device 21 and other devices via wired communication and / or wireless communication.

[0024] 5 is a block diagram showing the configuration of the transmitter 22 of a mobile object according to an embodiment of the present disclosure. The transmitter 22 includes a control unit 220, a beam controller 221, a D / A converter 222, a low-pass filter 223, a mixer 224, an amplifier 225, a band-pass filter 226, and a transmitting antenna array 227. The control unit 220 controls the overall function of the transmitter 22. The control unit 220 may obtain a digital signal from the information processing device 21 and transmit the signal to the beam controller 221 based on a predetermined trigger.

[0025] The beam controller 221 controls the amplitude and phase of the digital signal generated by the information processing device 21, converts it into a digital signal for each antenna, and transmits it to the D / A converter 222. The D / A converter 222 is a digital-to-analog converter that receives the digital signal from the beam controller 221 and converts the digital signal into an analog signal based on a predetermined sampling frequency and a predetermined number of quantization bits. The predetermined sampling frequency can be, for example, 100 MHz or less.

[0026] The low-pass filter 223 receives the analog signal from the D / A converter 222 and filters out the analog signal having a frequency lower than a predetermined cutoff frequency. That is, the low-pass filter 223 band-limits the analog signal received from the D / A converter 222 to a frequency lower than the cutoff frequency.

[0027] The mixer 224 uses an oscillator or the like to convert the frequency of the analog signal received from the low-pass filter 223 to a predetermined intermediate frequency. For example, the mixer 224 converts an analog signal having a baseband frequency into an analog signal having an intermediate frequency of 2.4 GHz. The mixer 224 is also called a mixer.

[0028] The amplifier 225 amplifies the analog signal received from the mixer 224 by a predetermined gain. The amplifier 225 sends the amplified analog signal to the band-pass filter 226. The band-pass filter 226 receives the analog signal from the amplifier 225 and band-limits the analog signal to a predetermined frequency bandwidth. The band-pass filter 226 sends the band-limited analog signal to the transmitting antenna array 227.

[0029] The transmit antenna array 227 is an antenna array having a plurality of antennas. The transmit antenna array 227 receives the band-limited analog signal from the band-pass filter 226, and each of the plurality of antennas transmits a pilot signal 41, an estimated position 42, and a control signal / data signal 43.

[0030] 6 is a block diagram showing the configuration of the receiver 23 of a mobile object according to an embodiment of the present disclosure. The receiver 23 includes a controller 230, a receiving antenna array 231, a band-pass filter 232, an amplifier 233, a mixer 234, a low-pass filter 235, an A / D converter 236, and an estimator 237. The controller 230 controls the overall function of the receiver 23. The controller 230 may obtain an estimated position from the estimator 237 and transmit the estimated position to the information processing device 21.

[0031] The receiving antenna array 231 is an antenna array having a plurality of antennas, and receives the pilot signal 41, the estimated position 42, and the control / data signal 43 from the transmitting antenna array 227.

[0032] The bandpass filter 232 receives the pilot signal 41, the estimated position 42, and the control signal / data signal 43 from the receiving antenna array 231, and band-limits the pilot signal 41, the estimated position 42, and the control signal / data signal 43 to a predetermined frequency bandwidth. The bandpass filter 232 transmits the band-limited analog signal to the amplifier 233.

[0033] Amplifier 233 amplifies the analog signal received from band-pass filter 232 by a predetermined gain. Amplifier 233 sends the amplified analog signal to mixer 234. Mixer 234 converts the intermediate frequency of the analog signal received from amplifier 233 to a baseband frequency using an oscillator or the like. For example, mixer 234 converts an analog signal having an intermediate frequency of 2.4 GHz into an analog signal having a baseband frequency. Mixer 234 is also called a mixer.

[0034] The low-pass filter 235 receives the analog signal from the mixer 234 and filters out the analog signal having a frequency lower than a predetermined cutoff frequency. That is, the low-pass filter 235 band-limits the analog signal received from the mixer 234 to frequencies lower than the cutoff frequency.

[0035] The A / D converter 236 is an analog-to-digital converter that receives the analog signal from the low-pass filter 2335 and converts the analog signal into a digital signal based on a predetermined sampling frequency and a predetermined number of quantization bits. The A / D converter 236 sends the converted digital signal to the estimator 237.

[0036] The estimator 237 performs the following processing based on the received digital signal. If the digital signal is a pilot signal 41, the estimator 237 performs position estimation based on the pilot signal 41. If the digital signal is an estimated position 42, the estimator 237 acquires an estimated direction or estimated position transmitted from the mobile unit 2Rx based on information contained in the bit sequence of the estimated position 42. If the digital signal is a control signal / data signal 43, the estimator 237 transmits the digital signal to the information processing device 21, and the information processing device 21 demodulates the digital signal.

[0037] 7 is a schematic diagram showing an example of an antenna arrangement according to an embodiment of the present disclosure. The transmitting antenna array 227 includes a plurality of antennas 227A, 227B, ..., 227Y. The number of antennas included in the transmitting antenna array 227 is not limited to the number of antennas 227a, 227b, ..., 227y shown in FIG. 7. The receiving antenna array 231 may also have a configuration similar to that of the transmitting antenna array 227 shown in FIG.

[0038] The multiple antennas 227A, 227B, 227C, 227D, and 227E are arranged on a substantially straight line at intervals d from one another. The direction in which the multiple antennas 227A, 227B, 227C, 227D, and 227E are arranged is the X direction. Similarly, the multiple antennas 227F, 227G, 227H, 227I, and 227J are arranged on a substantially straight line in the X direction at intervals d from one another. Similarly, the multiple antennas 227K, ..., 227O, the multiple antennas 227P, ..., 227T, and the multiple antennas 227U, ..., 227Y are arranged on a substantially straight line in the X direction at intervals d from one another.

[0039] The multiple antennas 227A, 227F, 227K, 227P, and 227U are spaced apart by a distance d and arranged substantially linearly in a direction perpendicular to the X direction. The direction in which the multiple antennas 227A, 227F, 227K, 227P, and 227U are arranged is defined as the Y direction. Similarly, the multiple antennas 227B, 227G, 227L, 227Q, and 227V are spaced apart by a distance d and arranged substantially linearly in the Y direction. Similarly, the multiple antennas 227C, 227H, 227M, 227R, and 227W, the multiple antennas 227D, 227I, 227N, 227S, and 227X, and the multiple antennas 227E, 227J, 227O, 227T, and 227Y are spaced apart by a distance d and arranged substantially linearly in the Y direction. That is, the plurality of antennas 227A, . . . , 227Y are arranged in a lattice pattern at intervals d in the X and Y directions.

[0040] The interval d may be, for example, half the wavelength of the pilot signal 41, the estimated position 42, and the control signal / data signal 43. If the signal frequency of the pilot signal 41 is, for example, 2.4 GHz, the interval d may be approximately 124.91 mm. In this embodiment, the multiple antennas 227A, ..., 227Y are arranged on the XY plane, but the configuration of the transmitting antenna array 227 is not limited to the example shown in FIG. 7. For example, the transmitting antenna array 227 may further include an antenna, which may be arranged at an interval d in the Z direction. In other words, the multiple antennas 227A, 227B, ... may be arranged in three-dimensional space.

[0041] 8 and 9 are schematic diagrams showing an example of the spatial directivity of an antenna array according to an embodiment of the present disclosure, and are polar coordinate diagrams showing the spatial directivity of the transmitting antenna array 227 when the moving object 2Tx is located at the origin O. In the polar coordinates, the radial value indicates the amount of attenuation [dB] of the directivity.

[0042] The directivity characteristic shown in Fig. 8 is an example of the directivity characteristic of the transmitting antenna array 227 when the moving body 2Tx transmits the pilot signal 41 to the moving body 2Rx, and the transmitting antenna array 227 forms a main lobe at an azimuth angle of 0 degrees in Fig. 8. The directivity characteristic (first directivity) shown in Fig. 8 is obtained by setting the coefficient C1 of the multiple antennas 227A, ..., 227Y as follows:

[0043]

number

[0044] When transmitting the pilot signal 41, the directional characteristics of the transmitting antenna array 227 are formed slowly, thereby reducing the number of times the mobile unit 2Tx performs beam scanning, or the mobile unit 2Tx can transmit the pilot signal 41 to the mobile unit 2Rx without performing beam scanning.

[0045] The directivity characteristic (second directivity) shown in FIG. 9 is obtained by setting the coefficient C2 of the plurality of antennas 227A, . . . , 227Y as follows:

[0046]

number

[0047] The directional characteristic shown in FIG. 9 is an example of a general directional characteristic of the transmitting antenna array 227, and the transmitting antenna array 227 forms a main lobe at an azimuth angle in the 0 degree direction. When the moving body 2Tx transmits a pilot signal 41 to the moving body 2Rx, the directional characteristic of the transmitting antenna array 227 is formed into a directional characteristic as shown in FIG. 9, and the moving body 2Tx performs beam scanning. Comparing the directional characteristic shown in FIG. 8 with the directional characteristic shown in FIG. 9, the main lobe of the directional characteristic shown in FIG. 9 is steeper than the main lobe of the directional characteristic shown in FIG. 8. The steepness of the main lobe of the directional characteristic may be expressed, for example, by the angle difference (referred to as a 3 dB beam width) from the angle at which the directional characteristic is formed (e.g., 0 degrees) to the angle at which the gain is attenuated by 3 dB. Note that in FIGS. 8 and 9, the main lobe of the directional characteristic of the transmitting antenna array 227 is formed in the 0 degree direction, but the main lobe of the directional characteristic of the transmitting antenna array 227 may be formed in another angle.

[0048] The directivity characteristic of the transmitting antenna array 227 shown in Fig. 9 is steeper than the directivity characteristic of the transmitting antenna array 227 shown in Fig. 8. Therefore, when a moving body 2Tx performs beam scanning using the transmitting antenna array 227 having the directivity characteristic shown in Fig. 9 for azimuth angles from -90 degrees to +90 degrees, the number of times beam scanning is performed by the moving body 2Tx is greater than when the moving body 2Tx performs beam scanning using the transmitting antenna array 227 having the directivity characteristic shown in Fig. 8. For example, when the transmitting antenna array 227 having the directivity characteristic shown in Fig. 8 performs beam scanning for azimuth angles from -90 degrees to +90 degrees, the number of beam scannings is assumed to be five. On the other hand, when the transmitting antenna array 227 having the directivity characteristic shown in Fig. 9 performs beam scanning for azimuth angles from -90 degrees to +90 degrees, the number of beam scannings may be 13.

[0049] When beam scanning, transmission and reception of a pilot signal 41, transmission and reception of an estimated position 42, and transmission and reception of a control signal / data signal 43 are performed within a unit time, an increase in the number of beam scanning operations may limit the time during which transmission and reception of the pilot signal 41, transmission and reception of the estimated position 42, and transmission and reception of the control signal / data signal 43 can be performed. By reducing the number of times the mobile station 2Tx performs beam scanning, or by transmitting the pilot signal 41 to the mobile station 2Rx without performing beam scanning, it is possible to ensure the time during which transmission and reception of the pilot signal 41, transmission and reception of the estimated position 42, and transmission and reception of the control signal / data signal 43 can be performed within a unit time. Furthermore, when the mobile station 2Tx receives the estimated position 42 and the position of the mobile station 2Rx becomes known, the mobile station 2Tx may transmit the control signal / data signal 43 using a transmitting antenna array 227 having the directional characteristics shown in FIG. 9. By transmitting the control signal / data signal 43 using the steep directivity characteristics of the transmitting antenna array 227 as shown in FIG. 9, it may be possible to improve the quality of communication between the mobile unit 2Tx and the mobile unit 2Rx.

[0050] When the moving body 2Tx transmits the pilot signal 41 to the moving body 2Rx, by making the directivity characteristic of the transmitting antenna array 227 gentle, the number of times the moving body 2Tx performs beam scanning can be reduced, or the moving body 2Rx can receive the pilot signal 41 without beam scanning. This makes it possible to perform direction estimation or position estimation between the moving body 2Tx and the moving body 2Rx in a shorter time than when the moving body 2Tx performs beam scanning using a transmitting antenna array 227 with a steep directivity characteristic.

[0051] Fig. 10 is a sequence chart showing a position estimation process according to an embodiment of the present disclosure. Figs. 11 and 12 are schematic diagrams showing an example of the spatial directivity characteristics of an antenna array according to an embodiment of the present disclosure. Figs. 11 and 12 show the positional relationship between a mobile unit 2Tx and a mobile unit 2Rx and an example of the directivity characteristics formed by the transmitting antenna array 227 of the mobile unit 2Tx. In the example of Figs. 10-12, the mobile unit 2Tx transmits a pilot signal 41 and a control signal / data signal 43 to the mobile unit 2Rx, and the mobile unit 2Rx transmits an estimated position 42 to the mobile unit 2Tx.

[0052] In the examples of Figures 10-12, the moving body 2Tx moves in the +Y direction, and the moving body 2Rx moves in the -Y direction. That is, the moving body 2Tx and the moving body 2Rx move in directions that pass each other. At a certain time t, the moving body 2Tx and the moving body 2Rx have a directional relationship as shown in Figure 11. At a certain time t+1, the moving body 2Tx and the moving body 2Rx have a directional relationship as shown in Figure 12. Taking such a case as an example, the position estimation process of this embodiment will be described.

[0053] The moving object 2Tx controls the directivity of the transmitting antenna array 227 so that the directivity of the transmitting antenna array 227 becomes a gentle directivity (hereinafter referred to as the first directivity) as shown in FIG. 11 (step S100). In the example of FIG. 11, the first directivity has focal points at azimuth angles of 0 and 180 degrees. The first directivity has directivity in an azimuth angle range from −15 degrees in the focal direction to +15 degrees in the focal direction. That is, the first directivity has directivity in a range from −15 to +15 degrees (the focal direction is 0 degrees) and in a range from −165 to +165 degrees (the focal direction is 180 degrees). The gain difference between the gain at an azimuth angle of 0 degrees and the gain at an azimuth angle of −15 degrees may be approximately 3 dB. The gain difference between the gain at an azimuth angle of 0 degrees and the gain at an azimuth angle of +15 degrees may be approximately 3 dB. Similarly, the gain difference between the gain at an azimuth angle of 180 degrees and the gain at an azimuth angle of -165 degrees may be approximately 3 dB. The gain difference between the gain at an azimuth angle of 180 degrees and the gain at an azimuth angle of +165 degrees may be approximately 3 dB. The first directivity may have a wider azimuth angle range than the above example, or may have a narrower azimuth angle range than the above example. For example, when the mobile unit 2Tx and the mobile unit 2Rx move in the same direction, the first directivity may have a narrower azimuth angle range than the azimuth angle range in the example of FIG. 11.

[0054] In step S100, the moving body 2Tx may further perform beam scanning at a plurality of azimuth angles. For example, the moving body 2Tx may perform beam scanning at azimuth angles of 0 degree, 45 degrees, and 90 degrees to estimate a rough directional relationship between the moving body 2Tx and the moving body 2Rx. When performing beam scanning, it is desirable to know that the moving body 2Rx is located at an azimuth angle that does not fall in a blind spot of the directional characteristic formed by the transmitting antenna array 227 with respect to the moving body 2Tx.

[0055] The moving body 2Tx transmits a pilot signal 41 to the moving body 2Rx (step S101). When transmitting the pilot signal 41 to the moving body 2Rx, the moving body 2Tx may transmit the pilot signal 41 including the transmission time, GPS position information of the moving body 2Tx, speed information, acceleration information, and movement direction. The pilot signal 41 may include destination information of the moving body 2Tx, and may also include position information of obstacles near the moving body 2Tx.

[0056] The mobile unit 2Rx receives the pilot signal 41 from the mobile unit 2Tx and estimates the relative direction or relative position between the mobile unit 2Tx and the mobile unit 2Rx based on the pilot signal 41 (step S102). The mobile unit 2Rx may estimate the relative direction or relative position using, for example, a beamformer method, a Capon method, a linear prediction method, or the like. Furthermore, the mobile unit 2Rx may estimate the relative direction or relative position between the mobile unit 2Tx and the mobile unit 2Rx based on the time difference between the time when the mobile unit 2Tx transmits the pilot signal 41 and the time when the mobile unit 2Rx receives the pilot signal 41. Alternatively, the mobile unit 2Rx may estimate the relative direction or relative position between the mobile unit 2Tx and the mobile unit 2Rx based on the signal power of the pilot signal 41, or the like.

[0057] The moving body 2Rx transmits the estimated relative direction or relative position to the moving body 2Tx (step S103). When transmitting the estimated position 42 to the moving body 2Tx, the moving body 2Rx may transmit the estimated position 42 including the transmission time, GPS position information of the moving body 2Rx, speed information, acceleration information, and movement direction. The estimated position 42 may include destination information of the moving body 2Rx, and may also include position information of obstacles near the moving body 2Rx.

[0058] The moving body 2Tx transmits destination information to the moving body 2Rx via the pilot signal 41, and the moving body 2Rx transmits destination information to the moving body 2Tx via the estimated position 42, so that the moving body 2Tx and the moving body 2Rx can share each other's destination information, etc. This can make it easier for the moving body 2Tx and the moving body 2Rx to estimate each other's moving direction, etc. Furthermore, based on the destination information, GPS position information, and map information, the moving body 2Tx and the moving body 2Rx can easily estimate each other's moving direction, etc. within a short period of time.

[0059] Based on the position information of an obstacle near the moving body 2Tx and the position information of an obstacle near the moving body 2Rx, the moving body 2Tx and the moving body 2Rx may form the directional characteristics of the transmitting antenna array 227 so as to avoid the direction of the obstacle. The position information of the obstacle can be acquired based on, for example, GPS position information and map information.

[0060] When the moving body 2Tx receives the estimated position 42 from the moving body 2Rx, the moving body 2Tx controls the directivity of the transmitting antenna array 227 so that the directivity of the transmitting antenna array 227 becomes a steep directivity (hereinafter referred to as the second directivity) as shown in FIG. 12 (step S110). In the example of FIG. 12, the second directivity has focal points at azimuth angles of 0 degrees and 180 degrees. The second directivity has directivity in the azimuth angle range of −5 degrees to +5 degrees in the focal direction. That is, the second directivity has directivity in the range of −5 degrees to +5 degrees (the focal direction is 0 degrees) and in the range of −175 degrees to +175 degrees (the focal direction is 180 degrees). The gain difference between the gain at an azimuth angle of 0 degrees and the gain at an azimuth angle of −5 degrees may be approximately 3 dB. The gain difference between the gain at an azimuth angle of 0 degrees and the gain at an azimuth angle of +5 degrees may be approximately 3 dB. Similarly, the gain difference between the gain at an azimuth angle of 180 degrees and the gain at an azimuth angle of −175 degrees may be approximately 3 dB. The gain difference between the gain at an azimuth angle of 180 degrees and the gain at an azimuth angle of +175 degrees may be approximately 3 dB. The second directivity may have a wider azimuth angle range than the above example, or may have a narrower azimuth angle range than the above example. Here, the moving body 2Tx does not necessarily have to control the directivity characteristic of the transmitting antenna array 227 so that the transmitting antenna array 227 has the second directivity. For example, when the relative speed between the moving body 2Tx and the moving body 2Rx is greater than a predetermined speed, the moving body 2Tx may control the directivity characteristic of the transmitting antenna array 227 so that the transmitting antenna array 227 has the first directivity. By the mobile 2Tx controlling the directional characteristics of the transmitting antenna array 227 so that the transmitting antenna array 227 has a first directivity, the mobile 2Tx can include the mobile 2Rx in the azimuth angle of the main lobe of the directional characteristics of the transmitting antenna array 227.

[0061] That is, the directivity of the transmitting antenna array 227 can be controlled based on the relative positional relationship between the moving body 2Tx and the moving body 2Rx, the relative speed, etc. For example, when the moving body 2Rx is temporarily stopped, the moving body 2Tx may control the directivity of the transmitting antenna array 227 so that the directivity of the transmitting antenna array 227 becomes a steep directivity (second directivity). For example, when the relative speed between the moving body 2Tx and the moving body 2Rx is greater than a predetermined threshold, the moving body 2Tx may control the directivity of the transmitting antenna array 227 so that the directivity of the transmitting antenna array 227 becomes a gentle directivity (first directivity).

[0062] The moving body 2Tx transmits a control signal / data signal 43 to the moving body 2Rx (step S111). The coding method and modulation method of the control signal / data signal 43 may be determined according to the relative positional relationship, relative speed, moving direction, GPS position information, etc. of the moving body 2Tx and the moving body 2Rx. Alternatively, the coding method and modulation method of the control signal / data signal 43 may be determined according to the directivity characteristic of the transmitting antenna array 227.

[0063] The moving body 2Rx receives the control signal / data signal 43 from the moving body 2Tx and demodulates and decodes the control signal or data signal (step S112). The moving body 2Rx may control the directivity of the receiving antenna array 231 to form the directivity of the receiving antenna array 231 in the direction of the moving body 2Tx. For example, when the relative speed between the moving body 2Tx and the moving body 2Rx is smaller than a predetermined threshold, the moving body 2Rx may control the directivity of the receiving antenna array 231 so that the directivity of the receiving antenna array 231 becomes a steep directivity (second directivity).

[0064] The mobile station 2Rx transmits an acknowledgment (ACK) or a negative acknowledgment (NACK) to the mobile station 2Tx based on the decoding result of the control signal / data signal 43 (step S113). When the mobile station 2Tx receives the ACK or NACK from the mobile station 2Rx, the mobile station 2Tx updates the transmission period P of the pilot signal 41, the control information of the transmitting antenna array 227, the modulation method of the transmission signal, etc. (step S114). For example, in steps S111 and S112, if the signal-to-noise ratio of the control signal / data signal 43 is small and the bit error rate in the demodulation of the control signal or data signal by the mobile station 2Rx is large, the mobile station 2Tx may make the directional characteristic of the transmitting antenna array 227 steeper based on the relative speed between the mobile station 2Tx and the mobile station 2Rx, etc.

[0065] For example, when the moving speed, acceleration, angular velocity, etc. of the moving body 2Tx is high, or when the moving speed, acceleration, angular velocity, etc. of the moving body 2Rx is high, the moving body 2Tx may decrease the transmission period P of the pilot signal 41. Depending on the positional relationship between the moving body 2Tx and the moving body 2Rx, the moving body 2Tx may decrease or increase the transmission period P of the pilot signal 41. In other words, the moving body 2Tx can control the transmission period P of the pilot signal 41 depending on the positional relationship between the moving body 2Tx and the moving body 2Rx, the relative speed, the relative acceleration, and the relative angular velocity.

[0066] The mobile station 2Tx may change the modulation method of the control signal / data signal 43, for example, from multi-level quadrature amplitude modulation (QAM) to multi-level phase shift keying (PSK), etc. In other words, the mobile station 2Tx can update the transmission period P of the pilot signal 41, the control information for the transmitting antenna array 227, the modulation method of the transmission signal, etc., depending on the positional relationship between the mobile station 2Tx and the mobile station 2Rx, their relative speeds, the conditions of the propagation path, etc.

[0067] When the moving body 2Tx transmits the pilot signal 41 to the moving body 2Rx, the directivity characteristic of the transmitting antenna array 227 is set to a gentle directivity characteristic, thereby reducing the number of times the moving body 2Tx performs beam scanning, or even eliminating beam scanning, allowing the moving body 2Tx and the moving body 2Rx to transmit and receive the pilot signal 41. This allows position estimation to be performed in a short time between the moving body 2Tx and the moving body 2Rx, regardless of the relative speed, relative acceleration, relative angular velocity, etc. between the moving body 2Tx and the moving body 2Rx.

[0068] According to the present disclosure, even if a position estimation device is installed in a mobile body, it is possible to estimate the position of other mobile bodies.

[0069] [Other embodiments] 13 is a block diagram showing a position estimation device according to an embodiment of the present disclosure. The position estimation device 100 includes a beam control means 101, a transmitting means 102, and a receiving means 103. The beam control means 101 controls the directivities of multiple transmitting antennas. The transmitting means 102 transmits a pilot signal to a receiver. The receiving means 103 receives an estimated position estimated by the receiver from the receiver. When the transmitting means 102 transmits the pilot signal to the receiver, the beam control means 101 controls the directivities of the multiple transmitting antennas so that the multiple transmitting antennas have a gentle directivity (first directivity). When the receiving means 103 receives the estimated position from the receiver, the beam control means 101 controls the directivities of the multiple transmitting antennas so that the multiple transmitting antennas have a steep directivity (second directivity). Here, the beam control means 101 controls the directivity of the multiple transmitting antennas so that the directivity after the receiving means 103 receives the estimated position is steeper than the directivity when the transmitting means 102 transmits the pilot signal.

[0070] Furthermore, the scope of each embodiment also includes a processing method in which a program that operates the configuration of each embodiment to realize the functions of the above-described embodiments is recorded on a recording medium, the program recorded on the recording medium is read as code, and the program is executed on a computer. In other words, a computer-readable recording medium is also included in the scope of each embodiment. Furthermore, each embodiment includes not only a recording medium on which the above-described computer program is recorded, but also the computer program itself.

[0071] Examples of the recording medium that can be used include a floppy disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM (Compact Disc-Read Only Memory), a magnetic tape, a non-volatile memory card, and a ROM. In addition, the scope of each embodiment is not limited to programs that execute processing by themselves recorded on the recording medium, but also includes programs that execute processing by operating on an OS (Operating System) in cooperation with other software and functions of an expansion board.

[0072] Although the present disclosure has been described above with reference to the embodiments, the present disclosure is not limited to the above-described embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and detailed description of the present disclosure within the scope of the present disclosure. Furthermore, each embodiment can be combined with other embodiments as appropriate.

[0073] Some or all of the above-described embodiments can be described as, but are not limited to, the following supplementary notes.

[0074] (Appendix 1) beam control means for controlling the directivity of a plurality of transmitting antennas; transmitting means for transmitting a pilot signal to a receiver; receiving means for receiving from the receiver the estimated position estimated by the receiver; the beam control means controls the directivities of the plurality of transmitting antennas so that the plurality of transmitting antennas have a first directivity when the transmitting means transmits the pilot signal to the receiver; the beam control means controls the directivities of the plurality of transmitting antennas based on the estimated positions so that the plurality of transmitting antennas have a second directivity; The position estimation device, wherein the second directivity is steeper than the first directivity.

[0075] (Appendix 2) the receiving means receives receiver information from the receiver; 2. The position estimation device of claim 1, wherein the receiver information includes at least one of the time when the receiver transmits the receiver information, the position information of the receiver, the speed information of the receiver, the acceleration information of the receiver, the moving direction information of the receiver, and the destination information of the receiver.

[0076] (Appendix 3) the transmitting means transmits transmitter information of a transmitter having the location estimation device; 2. A position estimation device as described in Appendix 1, wherein the transmitter information includes at least one of the time when the transmitter information is transmitted, the position information of the transmitter, the speed information of the transmitter, the acceleration information of the transmitter, the moving direction information of the transmitter, and the destination information of the transmitter.

[0077] (Appendix 4) the receiving means receives, from the receiver, position information of an obstacle in the vicinity of the receiver; 2. A position estimation device as described in claim 1, wherein the beam control means forms the second directivity based on position information of the obstacle.

[0078] (Appendix 5) the transmitting means transmits to the receiver position information of an obstacle in the vicinity of a transmitter having the position estimation device; 2. The position estimation device according to claim 1, wherein the receiving means receives the estimated position from the receiver based on the position information of the obstacle.

[0079] (Appendix 6) A position estimation device as described in Appendix 2, wherein the beam control means controls the directivity of the multiple transmitting antennas so that the multiple transmitting antennas have the second directivity based on the relative speed between the receiver and a transmitter having the position estimation device.

[0080] (Appendix 7) 3. The position estimation device according to claim 2, wherein the transmitting means determines a transmission period of the pilot signal based on the receiver information.

[0081] (Appendix 8) 4. The position estimation device according to claim 3, wherein the transmitting means determines a transmission period of the pilot signal based on the transmitter information.

[0082] (Appendix 9) a beam control step of controlling the directivities of a plurality of transmitting antennas; a transmitting step of transmitting a pilot signal to a receiver; a receiving step of receiving from the receiver an estimated position estimated by the receiver, the beam control step controls the directivities of the plurality of transmitting antennas so that the plurality of transmitting antennas have a first directivity when the transmitting step transmits the pilot signal to the receiver; the beam control step controls the directivities of the plurality of transmitting antennas based on the estimated positions so that the plurality of transmitting antennas have a second directivity; The position estimation method, wherein the second directivity is steeper than the first directivity.

[0083] (Appendix 10) The receiving step receives receiver information from the receiver, 10. The location estimation method of claim 9, wherein the receiver information includes at least one of a time when the receiver transmits the receiver information, location information of the receiver, speed information of the receiver, acceleration information of the receiver, moving direction information of the receiver, and destination information of the receiver.

[0084] (Appendix 11) the transmitting step includes transmitting transmitter information of a transmitter having the location estimation method; 10. The location estimation method of claim 9, wherein the transmitter information includes at least one of a time when the transmitter information is transmitted, location information of the transmitter, speed information of the transmitter, acceleration information of the transmitter, moving direction information of the transmitter, and destination information of the transmitter.

[0085] (Appendix 12) the receiving step receives, from the receiver, position information of an obstacle in the vicinity of the receiver; 10. The position estimation method of claim 9, wherein the beam control step forms the second directivity based on position information of the obstacle.

[0086] (Appendix 13) The transmitting step transmits position information of an obstacle in the vicinity of a transmitter having the position estimation method to the receiver; 10. The position estimation method of claim 9, wherein the receiving step receives the estimated position from the receiver based on the position information of the obstacle.

[0087] (Appendix 14) 11. The position estimation method of claim 10, wherein the beam control step controls the directivities of the plurality of transmitting antennas so that the plurality of transmitting antennas have the second directivity based on a relative velocity between the receiver and a transmitter having the position estimation method.

[0088] (Appendix 15) 11. The position estimation method according to claim 10, wherein the transmitting step determines a transmission period of the pilot signal based on the receiver information.

[0089] (Appendix 16) 12. The position estimation method according to claim 11, wherein the transmitting step determines a transmission period of the pilot signal based on the transmitter information.

[0090] (Appendix 17) a beam control step of controlling the directivities of a plurality of transmitting antennas; a transmitting step of transmitting a pilot signal to a receiver; a receiving step of receiving from the receiver an estimated position estimated by the receiver, the beam control step controls the directivities of the plurality of transmitting antennas so that the plurality of transmitting antennas have a first directivity when the transmitting step transmits the pilot signal to the receiver; the beam control step controls the directivities of the plurality of transmitting antennas based on the estimated positions so that the plurality of transmitting antennas have a second directivity; The second directivity is steeper than the first directivity.

[0091] (Appendix 18) The receiving step receives receiver information from the receiver, 18. The location estimation program of claim 17, wherein the receiver information includes at least one of the time when the receiver transmits the receiver information, the position information of the receiver, the speed information of the receiver, the acceleration information of the receiver, the moving direction information of the receiver, and the destination information of the receiver.

[0092] (Appendix 19) the transmitting step includes transmitting transmitter information of a transmitter having the location estimation program; 18. A location estimation program as described in Appendix 17, wherein the transmitter information includes at least one of a time when the transmitter information is transmitted, position information of the transmitter, speed information of the transmitter, acceleration information of the transmitter, movement direction information of the transmitter, and destination information of the transmitter.

[0093] (Appendix 20) the receiving step receives, from the receiver, position information of an obstacle in the vicinity of the receiver; 18. The position estimation program according to claim 17, wherein the beam control step forms the second directivity based on position information of the obstacle.

[0094] (Appendix 21) the transmitting step includes transmitting position information of an obstacle in the vicinity of a transmitter having the position estimation program to the receiver; 18. The position estimation program according to claim 17, wherein the receiving step receives the estimated position from the receiver based on the position information of the obstacle.

[0095] (Appendix 22) 19. The location estimation program of claim 18, wherein the beam control step controls the directivity of the plurality of transmitting antennas so that the plurality of transmitting antennas have the second directivity based on a relative speed between the receiver and a transmitter having the location estimation program.

[0096] (Appendix 23) 19. The position estimation program according to claim 18, wherein the transmitting step determines a transmission period of the pilot signal based on the receiver information.

[0097] (Appendix 24) 20. The position estimation program according to claim 19, wherein the transmitting step determines a transmission period of the pilot signal based on the transmitter information.

[0098] Location estimation device. [Explanation of symbols]

[0099] 1: Location estimation system 2: Moving object 21: Information processing device 22: Transmitter 23: Receiving unit 4:Signal 41: Pilot signal 42:Estimated position 43: Control signal / data signal

Claims

1. beam control means for controlling the directivity of a plurality of transmitting antennas; transmitting means for transmitting a pilot signal to a receiver; receiving means for receiving from the receiver the estimated position estimated by the receiver; the beam control means controls the directivities of the plurality of transmitting antennas so that the plurality of transmitting antennas have a first directivity when the transmitting means transmits the pilot signal to the receiver; the beam control means controls the directivities of the plurality of transmitting antennas based on the estimated positions so that the plurality of transmitting antennas have a second directivity; The position estimation device, wherein the second directivity is steeper than the first directivity.

2. the receiving means receives receiver information from the receiver; 2. The position estimation device according to claim 1, wherein the receiver information includes at least one of a time when the receiver transmits the receiver information, position information of the receiver, speed information of the receiver, acceleration information of the receiver, moving direction information of the receiver, and destination information of the receiver.

3. the transmitting means transmits transmitter information of a transmitter having the location estimation device; 2. The position estimation device according to claim 1, wherein the transmitter information includes at least one of a time when the transmitter information is transmitted, position information of the transmitter, speed information of the transmitter, acceleration information of the transmitter, movement direction information of the transmitter, and destination information of the transmitter.

4. the receiving means receives, from the receiver, position information of an obstacle in the vicinity of the receiver; 2. The position estimation device according to claim 1, wherein said beam control means forms said second directivity based on position information of said obstacle.

5. the transmitting means transmits to the receiver position information of an obstacle in the vicinity of a transmitter having the position estimation device; 2. The position estimation device according to claim 1, wherein said receiving means receives said estimated position from said receiver based on said position information of said obstacle.

6. 3. The position estimation device according to claim 2, wherein the beam control means controls the directivities of the plurality of transmitting antennas so that the plurality of transmitting antennas have the second directivity based on a relative speed between the receiver and a transmitter having the position estimation device.

7. 3. The position estimation device according to claim 2, wherein said transmitting means determines a transmission period of said pilot signal based on said receiver information.

8. 4. The position estimation device according to claim 3, wherein said transmitting means determines a transmission period of said pilot signal based on said transmitter information.

9. a beam control step of controlling the directivities of a plurality of transmitting antennas; a transmitting step of transmitting a pilot signal to a receiver; a receiving step of receiving from the receiver the estimated position estimated by the receiver, the beam control step controls the directivities of the plurality of transmitting antennas so that the plurality of transmitting antennas have a first directivity when the transmitting step transmits the pilot signal to the receiver; the beam control step controls the directivities of the plurality of transmitting antennas based on the estimated positions so that the plurality of transmitting antennas have a second directivity; The position estimation method, wherein the second directivity is steeper than the first directivity.

10. a beam control step of controlling the directivities of a plurality of transmitting antennas; a transmitting step of transmitting a pilot signal to a receiver; a receiving step of receiving from the receiver the estimated position estimated by the receiver, the beam control step controls the directivities of the plurality of transmitting antennas so that the plurality of transmitting antennas have a first directivity when the transmitting step transmits the pilot signal to the receiver; the beam control step controls the directivities of the plurality of transmitting antennas based on the estimated positions so that the plurality of transmitting antennas have a second directivity; The second directivity is steeper than the first directivity.

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