WO2021132430A1

WO2021132430A1 - Receiver, receiving system, transmitter, receiving method, and program

Info

Publication number: WO2021132430A1
Application number: PCT/JP2020/048353
Authority: WO
Inventors: 真理中西; 一弘松本; 柴野　伸之; 尚樹本間
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2019-12-24
Filing date: 2020-12-24
Publication date: 2021-07-01
Also published as: JP7450231B2; JPWO2021132430A1

Abstract

The present disclosure addresses the problem of improving the accuracy in estimation of the direction of a transmitter. A receiver (2) comprises a plurality of antennas (11), a phase synthesis unit (13), an output unit (14), and a change unit (15). The plurality of antennas (11) receive radio signals. The phase synthesis unit (13) performs a synthesizing process with respect to a plurality of input signals (IS1 to IS3) based on the radio signals to generate composite signals (SS1 to SS4). The change unit (15) performs a changing process to change at least one element related to the processes from receiving the radio signals to generating the composite signals (SS1 to SS4). The phase synthesis unit (13) generates first composite signals (SS1 to SS4) before the changing process performed by the change unit (15), and generates second composite signals (SS1 to SS4) after the changing process performed by the change unit (15). The output unit (14) outputs first composite signals (SS1 to SS4) and second composite signals (SS1 to SS4).

Description

Receivers, receiving systems, transmitters, receiving methods and programs

The present disclosure relates to receivers, receiving systems, transmitters, receiving methods and programs, and more specifically to receivers, receiving systems, transmitters, receiving methods and programs that generate multiple signals.

The communication terminal device (receiver) described in Patent Document 1 estimates the arrival direction of the beacon signal (radio signal) transmitted by the beacon device (transmitter) based on the received signal strength (RSSI).

However, in the communication terminal device (receiver) described in Patent Document 1, an error may occur when estimating the arrival direction of the beacon signal due to the occurrence of multipath. Therefore, it has been desired to improve the estimation accuracy of the arrival direction of the beacon signal.

JP-A-2017-216567

The present disclosure has been made in view of the above reasons, and an object of the present disclosure is to provide a receiver, a receiving system, a transmitter, a receiving method, and a program capable of improving the estimation accuracy of the arrival direction of a radio signal.

In order to solve the above problems, the receiver according to one aspect of the present disclosure includes a plurality of antennas, a phase synthesizer, an output unit, and a change unit. The plurality of antennas receive radio signals. The phase synthesizing unit performs synthesis processing on a plurality of input signals based on the radio signals input from the plurality of antennas, and generates a composite signal for estimating the arrival direction of the radio signals. The output unit outputs the combined signal. The change unit performs a change process for changing at least one element related to the process from the reception of the radio signal to the generation of the composite signal. The phase synthesizer generates a first composite signal as the composite signal before the change process by the changer. In addition, the phase synthesis unit generates a second composite signal as the composite signal after the change processing by the change unit. The output unit outputs the first composite signal and the second composite signal.

The transmitter according to one aspect of the present disclosure includes a phase synthesizer, a plurality of antennas, and a changer. The phase synthesizing unit performs synthesis processing on a plurality of input signals based on a plurality of original signals to generate a plurality of radio signals. The plurality of antennas transmit the plurality of radio signals. The change unit performs a change process for changing at least one element related to the process from the reception of the plurality of original signals to the transmission of the plurality of radio signals. The phase synthesizing unit generates a plurality of first radio signals as the plurality of radio signals before the change processing by the change unit. Further, the phase synthesizing unit generates a plurality of second radio signals as the plurality of radio signals after the change processing by the change unit. The plurality of antennas transmit the plurality of first radio signals and the plurality of second radio signals.

The receiving method according to one aspect of the present disclosure includes a receiving step, a first phase synthesis step, a first output step, a change step, a second phase synthesis step, and a second output step. .. In the reception step, the radio signal is received. In the first phase synthesis step, a combination process is performed on a plurality of input signals based on the radio signal, and a first composite signal for estimating the arrival direction of the radio signal is generated. In the first output step, the first composite signal generated in the first phase synthesis step is output. In the change step, at least one element related to the processing from the reception step to the first phase synthesis step is changed. In the second phase synthesis step, after the change step, a second composite signal different from the first composite signal generated in the first phase synthesis step is generated. In the second output step, the second composite signal generated in the second phase synthesis step is output.

The program according to one aspect of the present disclosure causes one or more processors to execute the receiving method.

FIG. 1 is a schematic view showing an outline of the receiving system and the transmitter of the first embodiment. FIG. 2 is a block diagram showing a functional configuration of the receiving system of the first embodiment. FIG. 3 is a schematic view showing an outline of the receiving system and the transmitter of the second embodiment. FIG. 4 is a block diagram showing a functional configuration of the transmitter of the second embodiment.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the embodiments described below, the elements that are common to each other are designated by the same reference numerals, and duplicate description of the common elements will be omitted.

(First Embodiment)
(1) Outline First, an outline of a receiver, a receiving system, a transmitter, a receiving method, and a program according to the present embodiment will be described with reference to FIG. The transmitter 4 of the present embodiment is composed of, for example, a beacon device that transmits a beacon signal (radio signal) according to the standard of BLE (Bluetooth (registered trademark) Low Energy) (hereinafter, referred to as “BLE”). Will be done. However, the transmitter 4 is not limited to the beacon device that transmits the beacon signal according to the BLE standard. The transmitter 4 may be, for example, a device that transmits a radio signal according to the standard of WiFi (registered trademark).

The receiving system 1 includes a plurality of (three in the illustrated example) antennas 11 for receiving the radio signal transmitted by the transmitter 4. The plurality of antennas 11 of the present embodiment are array antennas including the antenna 11a, the antenna 11b, and the antenna 11c. In the following description, when the specific antenna 11 is described, the

antennas

11a, 11b, and 11c are described separately. Further, when a plurality of antennas 11 are described without distinction, they are simply referred to as antennas 11.

The receiving system 1 of the present embodiment is composed of a system capable of receiving a radio signal according to the BLE standard with a plurality of antennas 11. However, the receiving system 1 is not limited to a system capable of receiving a radio signal according to the BLE standard. The receiving system 1 may be, for example, a system capable of receiving a radio signal according to the WiFi standard. The receiving system 1 of the present embodiment estimates the positional direction of the transmitter 4 that has transmitted the radio signal based on the received signal strength (RSSI) of the radio signal received by the plurality of antennas 11.

(2) Details Hereinafter, the details of the receiving system 1 according to the present embodiment will be described with reference to FIGS. 1 and 2.

(2.1) Configuration of Reception System 1 As shown in FIG. 2, the reception system 1 of the present embodiment includes a receiver 2 and an estimation unit 3. The receiver 2 receives the radio signal transmitted by the transmitter 4. When the receiver 2 receives the radio signal, it generates synthetic signals SS1 to SS4 for estimating the arrival direction of the radio signal based on the radio signal. Further, the receiver 2 performs a change process for changing at least one element related to the process from the reception of the radio signal to the generation of the combined signals SS1 to SS4. The composite signals SS1 to SS4 generated by the receiver 2 based on the radio signal become different composite signals SS1 to SS4 before and after the change processing. The receiver 2 outputs the combined signals SS1 to SS4 before and after the change processing to the estimation unit 3.

The estimation unit 3 estimates the arrival direction of the radio signal based on the combined signals SS1 to SS4 before and after the change processing output from the receiver 2. The method by which the estimation unit 3 estimates the arrival direction of the radio signal will be described in the column of "(3) Arrival direction estimation".

(2.2) Configuration of Receiver 2 As shown in FIG. 2, the receiver 2 includes a plurality of antennas 11, a switching unit 12, a phase synthesis unit 13, an output unit 14, and a change unit 15. ..

The plurality of antennas 11 are electrically connected to the switching unit 12. Each of the plurality of antennas 11 receives the radio signal transmitted by the transmitter 4.

The switching unit 12 is a processing unit that is electrically connected between the plurality of antennas 11 and the phase synthesizing unit 13 and switches the electrical connection state between the plurality of antennas 11 and the phase synthesizing unit 13. The switching unit 12 includes a switch 16a, a switch 16b, and a switch 16c. In the following description, when the

switches

16a, 16b, and 16c are described without distinction, they are simply referred to as the switch 16. When the specific switch 16 is described, the

switches

16a, 16b, and 16c are described separately.

The switching unit 12 performs a switching operation of the switches 16a to 16c by being controlled by the changing unit 15. The switch 16b of the present embodiment has the antenna 11b and one of the first input terminal I1 and the second input terminal I2 of the phase synthesizer 17b included in the phase synthesizer 13 according to the control by the change unit 15. Electrically connect. In the following description, a state in which the antenna 11b and the first input terminal I1 of the phase synthesizer 17b are electrically connected by the switch 16b is referred to as a “first connection state”. Further, a state in which the antenna 11b and the second input terminal I2 of the phase synthesizer 17b are electrically connected by the switch 16b is referred to as a "second connection state".

The switch 16a is controlled so that the antenna 11a and the first input terminal I1 of the phase synthesizer 17a are always electrically connected. That is, the switch 16a of the present embodiment does not perform the switching operation. Therefore, the switch 16a may be a simple electrical path connecting the antenna 11a and the first input terminal I1 of the phase synthesizer 17a.

Further, the switch 16c is controlled so that the antenna 11c and the second input terminal I2 of the phase synthesizer 17c are always electrically connected. That is, the switch 16c of the present embodiment does not perform the switching operation. Therefore, the switch 16c may be a simple electric circuit that connects the antenna 11c and the second input terminal I2 of the phase synthesizer 17c.

However, the length of the electrical path from the antenna 11a to the phase synthesizer 17a, the length of the electrical path from the antenna 11b to the phase synthesizer 17b, and the length of the electrical path from the antenna 11c to the phase synthesizer 17c. It is preferable that the shavings have the same length. This is because if the lengths of the electrical paths from the antennas 11a to 11c to the phase synthesizers 17a to 17c are different, the accuracy in estimating the arrival direction of the radio signal is lowered. Therefore, in this embodiment, the switch 16a, the switch 16b, and the switch 16c are configured by the same switch 16.

The phase synthesizing unit 13 performs synthesis processing on a plurality of input signals IS1 to IS3 (signals IS4 to IS7) based on radio signals input from the plurality of antennas 11, and synthesizes for estimating the arrival direction of the radio signals. This is a processing unit that generates signals SS1 to SS4. Further, the phase synthesizer 13 of the present embodiment generates different composite signals SS1 to SS4 before and after the switch 16b is switched. Here, the composite signals SS1 to SS4 generated by the phase synthesizer 13 in the first connection state are referred to as the first composite signals SS1 to SS4. Further, in the second connection state, the composite signals SS1 to SS4 generated by the phase synthesizer 13 are referred to as the second composite signals SS1 to SS4.

The phase synthesizer 13 includes a phase synthesizer 17a, a phase synthesizer 17b, a phase synthesizer 17c, a phase synthesizer 17d, and a phase synthesizer 17e. In the following description, when the

phase synthesizers

17a, 17b, 17c, 17d, and 17e are described without distinction, they are simply referred to as the phase synthesizer 17. The phase synthesizer 17 is composed of, for example, a 90-degree hybrid unit (hybrid element). The phase synthesizer 17 of the present embodiment produces a signal having a power value 1 / √2 times that of the input signals IS1 to IS3 based on the radio signals input to the first input terminal I1 and the second input terminal I2. Output is performed from the 1st output terminal O1 and the 2nd output terminal O2. Further, the phase synthesizer 17 outputs a signal having the same phase from the first output terminal O1 as compared with the input signals IS1 to IS3 based on the radio signal input to the first input terminal I1, and the phase is delayed by 90 degrees. The signal is output from the second output terminal O2.

The phase synthesizer 17a outputs the in-phase signal IS4 from the first output terminal O1 with a power value 1 / √2 times that of the input signal IS1 based on the radio signal input to the first input terminal I1.

The phase synthesizer 17b has different input terminals electrically connected to the antenna 11b depending on the connection state. In the first connection state, the input signal IS2 based on the radio signal is input to the first input terminal I1. In this case, the phase synthesizer 17b outputs the signal IS5 whose power value is 1 / √2 times and whose phase is delayed by 90 degrees from the input signal IS2 from the second output terminal O2. Further, the phase synthesizer 17b outputs a signal IS6 having a power value 1 / √2 times that of the input signal IS2 and having the same phase from the first output terminal O1.

In the second connection state, the input signal IS2 is input to the second input terminal I2. In this case, the phase synthesizer 17b outputs a signal IS5 having a power value 1 / √2 times that of the input signal IS2 and having the same phase from the second output terminal O2. Further, the phase synthesizer 17b outputs a signal IS6 whose power value is 1 / √2 times that of the input signal IS2 and whose phase is delayed by 90 degrees from the first output terminal O1.

The phase synthesizer 17c outputs an in-phase signal IS7 from the second output terminal O2 with a power value 1 / √2 times that of the input signal IS3 based on the radio signal input to the second input terminal I2.

The phase synthesizer 17d receives the signal IS4 at the second input terminal I2 and the signal IS5 at the first input terminal I1. The phase synthesizer 17d produces a signal having a power value of 1 / √2 times that of the signal IS4 and a phase delay of 90 degrees, and a signal having a power value of 1 / √2 times that of the signal IS5 and having the same phase. The added combined signal SS1 is output from the first output terminal O1. Further, the phase synthesizer 17d has a signal having a power value of 1 / √2 times that of the signal IS4 and having the same phase, and a signal having a power value of 1 / √2 times that of the signal IS5 and having a phase delay of 90 degrees. , And the combined signal SS2 is output from the second output terminal O2.

The phase synthesizer 17e receives the signal IS6 at the second input terminal I2 and the signal IS7 at the first input terminal I1. The phase synthesizer 17e produces a signal having a power value of 1 / √2 times that of the signal IS6 and a phase delay of 90 degrees, and a signal having a power value of 1 / √2 times that of the signal IS7 and having the same phase. The added combined signal SS3 is output from the first output terminal O1. Further, the phase synthesizer 17e has a signal having a power value of 1 / √2 times that of the signal IS6 and having the same phase, and a signal having a power value of 1 / √2 times that of the signal IS7 and having a phase delay of 90 degrees. , And the combined signal SS4 is output from the second output terminal O2.

The change unit 15 is a processing unit that performs a change process for changing at least one element related to the process from the reception of the radio signal to the generation of the combined signals SS1 to SS4. The changing unit 15 of the present embodiment performs a process of controlling the switching unit 12 so as to switch the electrical connection state between the plurality of antennas 11 and the phase synthesizing unit 13 as at least a part of the changing process. Specifically, the changing unit 15 switches the electrical connection state between the antenna 11b and the phase synthesizer 17b by controlling the switch 16b to be switched. In the following description, it is assumed that the connection state between the antenna 11b and the phase synthesizer 17b is the first connection state until the change unit 15 performs the change processing. Further, it is assumed that the connection state between the antenna 11b and the phase synthesizer 17b is the second connection state after the change unit 15 performs the change processing. The change unit 15 performs the change process at a predetermined timing. The predetermined timing is, for example, a timing at which the phase synthesizing unit 13 outputs the combined signals SS1 to SS4, a constant timing set according to the interval at which the transmitter 4 transmits the radio signal, and the like.

The output unit 14 outputs the combined signals SS1 to SS4 generated by the phase synthesizing unit 13 to the estimation unit 3. Specifically, the output unit 14 has the first composite signals SS1 to SS4 generated by the phase synthesis unit 13 before the change processing is performed by the change unit 15, and the phase before the change processing is performed by the change unit 15. The second composite signals SS1 to SS4 generated by the synthesis unit 13 are output to the estimation unit 3.

(3) Estimating the Arrival Direction Next, a method in which the estimation unit 3 estimates the arrival direction of the radio signal will be described with reference to FIGS. 1 and 2. As shown in FIG. 1, the complex propagation channel between the antenna 11a and the transmitting antenna of the transmitter 4 is h1, the complex propagation channel between the antenna 11b and the transmitting antenna is h2, and the complex propagation channel between the antenna 11c and the transmitting antenna is Let h3 be the complex propagation channel. Further, the distance between the antenna 11a and the antenna 11b and the distance between the antenna 11b and the antenna 11c are d1. Further, it is assumed that the transmitter 4 exists at a position at an angle θ1 with respect to the broadside direction of the array antenna composed of the antenna 11a, the antenna 11b, and the antenna 11c. First, a case where the estimation unit 3 estimates the arrival direction of the radio signal based on the first combined signals SS1 to SS4 will be described.

The propagation channels can be collectively expressed as Eq. (1).

The correlation matrix of this propagation channel can be expressed by Eq. (2).

Here, the symbol H represents the complex conjugate transpose, and the symbol * represents the complex conjugate. Usually, the diagonal term of the correlation matrix R is a real number, and the off-diagonal term is a complex number. By obtaining the correlation matrix R, the estimation unit 3 can estimate the arrival direction of the radio signal. The estimation unit 3 obtains the correlation matrix R based on the information regarding the received signal strength.

Using the propagation channel of equation (1), the amplitudes of the plurality of first composite signals SS1 to SS4 input to the estimation unit 3 can be expressed as equations (3) to (6).

| Y1 | represents the amplitude of the composite signal SS1 output from the first output terminal O1 of the phase synthesizer 17d. | Y2 | represents the amplitude of the composite signal SS2 output from the second output terminal O2 of the phase synthesizer 17d. | Y3 | represents the amplitude of the composite signal SS3 output from the first output terminal O1 of the phase synthesizer 17e. | Y4 | represents the amplitude of the composite signal SS4 output from the second output terminal O2 of the phase synthesizer 17e. Further, the gain of the channel on the left side of the equations (3) to (6) can be expressed by the equations (7) to (10) from the received signal strength.

Focusing on the difference in gain obtained through the phase synthesizer 17d, it can be expressed as equation (12) from the relationship of equation (11).

The actual part of R12 and R21 can be obtained. Here, α represents the declination of R12.

Also, paying attention to the sum of the gains obtained through the phase synthesizer 17d, it can be expressed by the equation (13) from the relationship of the additive geometric mean.

Here, it is assumed that the propagation loss from the transmitting antenna to the antenna 11a of the transmitter 4 and the propagation loss from the transmitting antenna to the antenna 11b are equal, and | h1 | and | h2 | are substantially equal. When | h1 | and | h2 | are substantially equal, α, which is the argument of R12, can be expressed by the equation (14).

Further, when | h1 | and | h2 | are substantially equal, it can be expressed as equation (15).

Here, A is a real number constant. Among the correlation matrices R shown in the equation (2), the correlation matrix related to the composite signals SS1 and SS2 output from the phase synthesizer 17d is defined as R1. When the correlation matrix R1 is expressed using A and α, it can be expressed by the equation (16).

Next, paying attention to the difference in gain obtained through the phase synthesizer 17e, it can be expressed as Eq. (17).

The imaginary part of R23 and R32 can be obtained. Here, β represents the declination of R23. Further, paying attention to the sum of the gains obtained through the phase synthesizer 17e, it can be expressed by the equation (18) from the relation of the additive geometric mean.

Here, it is assumed that the propagation loss from the transmitting antenna of the transmitter 4 to the antenna 11b and the propagation loss from the transmitting antenna to the antenna 11c are equal, and | h2 | and | h3 | are substantially equal. When | h2 | and | h3 | are substantially equal, β, which is the argument of R23, can be expressed by the equation (19).

Similarly, when | h2 | and | h3 | are substantially equal, it can be expressed as equation (20).

Here, B is a real number constant. Of the correlation matrix R, the correlation matrix related to the composite signals SS3 and SS4 output from the phase synthesizer 17e is defined as R2. When the correlation matrix R2 is expressed using B and β, the equation (21) is obtained, and the correlation matrix R is estimated.

Here, since the declination is estimated in two ways for α and β, four kinds of solutions are estimated. Therefore, it is necessary to select the solutions of α and β. Here, as the solution of α and β, the combination of solutions having the smallest difference between α and β is selected. The transmitting antenna of the transmitter 4 and the

antennas

11a, 11b, 11c are sufficiently separated from each other, and the directions of the transmitting antennas of the transmitter 4 as seen from the

antennas

11a, 11b, 11c can all be regarded as equal θ (FIG. FIG. 1). Further, the antenna 11a, the antenna 11b, and the antenna 11c are aligned at equal intervals d1. Therefore, the difference in phase delay between h1 and h2 is equal to the difference in phase delay between h2 and h3. Here, α represents the difference in phase delay between h1 and h2, and β represents the difference in phase delay between h2 and h3. That is, α and β can be regarded as coincident. Therefore, by selecting the combination of solutions having the smallest difference between α and β as the solutions of α and β, it is possible to narrow down to two solutions.

Further, R13 represents the correlation of the radio signal between the antenna 11a and the antenna 11c. R13 can be expressed by the equation (22) using the obtained | R23 |.

From the above, the estimated correlation matrix R can be expressed as Eq. (23).

The estimation unit 3 estimates the direction of the transmitter 4 by using the MUSIC (MUltiple SIgnal Classification) method or the like for the correlation matrix R. There are various algorithms for direction estimation using the correlation matrix R, but in the present embodiment, a case where the estimation unit 3 performs direction estimation using the MUSIC method is illustrated.

The correlation matrix R can be expressed by Eq. (24) by eigenvalue decomposition.

Here, the equations (25) and (26) are used, and diag [] represents a diagonal matrix.

Also, v1, v2, and v3 are the first, second, and third eigenvectors, respectively. Further, λ1, λ2, and λ3 are the first, second, and third eigenvalues, respectively, and it is assumed that the equation (27) is used.

Further, λ1 corresponds to the electric power including the signal, and λ2 and λ3 correspond to the noise electric power. In the MUSIC method, the arrival direction of the radio signal is estimated by using the equation (28), which is an evaluation equation using such an eigenvector.

Here, equation (29) is called a steering vector.

D is the antenna spacing and λ is the wavelength. The estimation unit 3 substitutes various values for θ0 in the equation (28), and determines that the direction in which Pmusic is maximized is the departure direction of the radio signal. In the following description, the arrival direction estimated by the estimation unit 3 based on the first composite signals SS1 to SS4 will be referred to as the "first estimation direction".

Next, the estimation unit 3 estimates the arrival direction of the radio signal based on the second composite signals SS1 to SS4. Using the propagation channel of the equation (1), the amplitudes of the plurality of second composite signals SS1 to SS4 input to the estimation unit 3 can be expressed by the equations (30) to (33).

| Y1a | represents the amplitude of the composite signal SS1 output from the first output terminal O1 of the phase synthesizer 17d. | Y2a | represents the amplitude of the composite signal SS2 output from the second output terminal O2 of the phase synthesizer 17d. | Y3a | represents the amplitude of the composite signal SS4 output from the second output terminal O2 of the phase synthesizer 17e. | Y4a | represents the amplitude of the composite signal SS3 output from the first output terminal O1 of the phase synthesizer 17e. As shown by the formulas (30) to (33), how to express the amplitude of the plurality of first composite signals SS1 to SS4 and how to express the amplitude of each composite signal included in the plurality of second composite signals SS1 to SS4. different. Therefore, the estimation unit 3 can estimate the arrival direction different from the first estimation direction by obtaining the correlation matrix R using the equations (30) to (33). The description of a specific method for obtaining the correlation matrix R using the equations (30) to (33) will be omitted. In the following description, the arrival direction estimated by the estimation unit 3 based on the second composite signals SS1 to SS4 will be referred to as the "second estimation direction".

The estimation unit 3 estimates the arrival direction of the radio signal (positional direction of the transmitter 4) based on the first estimation direction and the second estimation direction. For example, the estimation unit 3 may estimate the arrival direction of the radio signal by averaging the first estimation direction and the second estimation direction. Since the estimation unit 3 of the present embodiment estimates the arrival direction of the radio signal based on a plurality of estimation directions, the estimation unit 3 is wireless as compared with the existing receiving system that estimates the arrival direction of the radio signal based on one estimation direction. The accuracy when estimating the arrival direction of the signal is improved.

As described above, the receiving system 1 of the present embodiment includes the receiver 2 and the estimation unit 3. The receiver 2 includes a plurality of antennas 11, a phase synthesizing unit 13, an output unit 14, and a changing unit 15. The plurality of antennas 11 receive the radio signal. The change unit 15 performs a change process for changing at least one element related to the process from the reception of the radio signal to the generation of the combined signals SS1 to SS4. The phase synthesizer 13 performs synthesis processing on a plurality of input signals IS1 to IS3 based on radio signals input from the plurality of antennas 11 to estimate the arrival direction of the radio signal (positional direction of the transmitter 4). Synthesized signals SS1 to SS4 are generated. The phase synthesis unit 13 generates the first composite signals SS1 to SS4 as the composite signals SS1 to SS4 before the change processing by the change unit 15. Further, the phase synthesizing unit 13 generates the second combined signals SS1 to SS4 as the combined signals SS1 to SS4 after the change processing by the changing unit 15. That is, the phase synthesizing unit 13 generates the combined signals SS1 to SS4 having different patterns before and after the change processing by the changing unit 15. In other words, the receiver 2 of the present embodiment can increase the patterns of the combined signals SS1 to SS4 for estimating the arrival direction of the radio signal. Then, the output unit 14 outputs the first composite signals SS1 to SS4 and the second composite signals SS1 to SS4 to the estimation unit 3. The estimation unit 3 estimates the arrival direction of the radio signal based on the first composite signals SS1 to SS4 and the second composite signals SS1 to SS4 output from the output unit 14 of the receiver 2. The estimation unit 3 can estimate the arrival direction of the radio signal based on the combined signals SS1 to SS4 of two or more patterns. Therefore, the estimation unit 3 estimates the arrival direction of the radio signal based on the combined signals SS1 to SS4 of one pattern. The accuracy of the arrival direction estimation is improved as compared with the case of doing so.

Further, the receiver 2 of the present embodiment further includes a switching unit 12. The switching unit 12 switches the electrical connection state between the plurality of antennas 11 and the phase synthesizing unit 13. More specifically, the electrical connection state between the antenna 11b and the phase synthesizer 17b is switched from the first connection state to the second connection state, or from the second connection state to the first connection state. The changing unit 15 performs a process of controlling the switching unit 12 so as to switch the electrical connection state between the plurality of antennas 11 and the phase synthesizing unit 13 as at least a part of the changing process. The receiver 2 can easily increase the patterns of the combined signals SS1 to SS4 for estimating the arrival direction of the radio signal by switching the electrical connection state between the plurality of antennas 11 and the phase synthesizer 13. .. Therefore, the receiver 2 can easily improve the accuracy of estimating the arrival direction of the radio signal.

Further, the phase synthesis unit 13 of the present embodiment is provided with a plurality of input units (input terminals) that are electrically connected to the plurality of antennas 11 and to which a wireless signal is input. Specifically, there are four input terminals: a first input terminal I1 of the phase synthesizer 17a, a first input terminal I1 and a second input terminal I2 of the phase synthesizer 17b, and a second input terminal I2 of the phase synthesizer 17c. Is. The plurality of antennas 11 of the present embodiment are three

antennas

11a, 11b, and 11c. That is, the number of the plurality of antennas 11 of the present embodiment is equal to or less than the number of the plurality of input units. Since the number of antennas 11 is less than or equal to the number of input units, the configuration of the receiver 2 (reception system 1) can be made compact. Further, the receiver 2 switches the electrical connection state between the plurality of antennas 11 and the input unit to obtain a wireless signal pattern for estimating the arrival direction of the wireless signal without increasing the number of antennas 11. It can be easily increased. That is, the receiver 2 can improve the accuracy of estimating the arrival direction of the radio signal without increasing the number of antennas 11. However, even if the number of antennas 11 is larger than the number of input units, the effect of improving the estimation accuracy of the arrival direction of the radio signal of the receiving system 1 in the present embodiment is not lost. .. Therefore, the number of antennas 11 of the receiver 2 may be larger than the number of input units.

(Second Embodiment)
(1) Outline The outline of the transmitter 4a and the receiving system 1a of the second embodiment will be described with reference to FIG. The transmitter 4a of the present embodiment includes a plurality of (three in the illustrated example) antennas 21 for transmitting a plurality of radio signals. The plurality of antennas 21 of this embodiment are array antennas including the antenna 21a, the antenna 21b, and the antenna 21c. In the following description, when a specific antenna 21 is described, the

antennas

21a, 21b, and 21c are described separately. Further, when a plurality of antennas 21 are described without distinction, they are simply described as antennas 21.

The receiving system 1a of the present embodiment includes a receiving antenna that receives a plurality of radio signals transmitted from the plurality of antennas 21. The receiving system 1a of the present embodiment is a receiving system that estimates the position direction of the transmitter 4a that has transmitted a plurality of radio signals based on the received signal strength of the plurality of radio signals received by the receiving antenna, for example, a smartphone or the like. Consists of.

(2) Configuration of Transmitter 4a Hereinafter, the configuration of the transmitter 4a according to the present embodiment will be described with reference to FIG. As shown in FIG. 4, the transmitter 4a includes a plurality of antennas 21, a switching unit 22, a phase synthesis unit 23, a source signal generation unit 24, and a change unit 25.

The plurality of antennas 21 are electrically connected to the switching unit 22. Each of the plurality of antennas 21 transmits a plurality of radio signals RS1 to RS3 generated by the phase synthesizer 23.

The switching unit 22 is a processing unit that is electrically connected between the plurality of antennas 21 and the phase synthesizing unit 23 and switches the electrical connection state between the plurality of antennas 21 and the phase synthesizing unit 23. The switching unit 22 includes a switch 26a, a switch 26b, and a switch 26c. In the following description, when the

switches

26a, 26b, and 26c are described without distinction, they are simply referred to as the switch 26. Further, when the specific switch 26 is described, the

switches

26a, 26b, and 26c are described separately.

The switching unit 22 performs a switching operation of the switches 26a to 26c by being controlled by the changing unit 25. The switch 26b of the present embodiment has an antenna 21b and one of the first output terminal O1 and the second output terminal O2 of the phase synthesizer 27b included in the phase synthesizer 23, according to the control by the change unit 25. Electrically connect. In the following description, a state in which the antenna 21b and the second output terminal O2 of the phase synthesizer 27b are electrically connected by the switch 26b will be referred to as a “first connection state”. Further, a state in which the antenna 21b and the first output terminal O1 of the phase synthesizer 27b are electrically connected by the switch 26b is referred to as a "second connection state".

The switch 26a is controlled so that the antenna 21a and the second output terminal O2 of the phase synthesizer 27a are always electrically connected. That is, the switch 26a of the present embodiment does not perform the switching operation. Therefore, the switch 26a may be a simple electrical path connecting the antenna 21a and the second output terminal O2 of the phase synthesizer 27a.

Further, the switch 26c is controlled so that the antenna 21c and the first output terminal O1 of the phase synthesizer 27c are always electrically connected. That is, the switch 26c of the present embodiment does not perform the switching operation. Therefore, the switch 26c may be a simple electric circuit that connects the antenna 21c and the first output terminal O1 of the phase synthesizer 27c.

However, the length of the electrical path from the antenna 21a to the phase synthesizer 27a, the length of the electrical path from the antenna 21b to the phase synthesizer 27b, and the length of the electrical path from the antenna 21c to the phase synthesizer 27c. It is preferable that the shavings have the same length. This is because if the lengths of the electrical paths from the antennas 21a to 21c to the phase synthesizers 27a to 27c are different, the accuracy of the receiving system 1a in estimating the arrival direction of the radio signal is lowered. Therefore, in this embodiment, the switch 26a, the switch 26b, and the switch 26c are configured by the same switch 26.

The original signal generation unit 24 is a processing unit that generates original signals BS1 to BS4 that are sources of a plurality of radio signals RS1 to RS3 transmitted by the plurality of antennas 21 and include predetermined information such as identification information. Is. The original signal generator 24 includes the original signal generators 24a to 24d. The original signal generator 24a is electrically connected to the first input terminal I1 of the phase synthesizer 27d of the phase synthesizer 23 to generate the original signal BS1. The original signal generator 24b is electrically connected to the second input terminal I2 of the phase synthesizer 27d to generate the original signal BS2. The original signal generator 24c is electrically connected to the first input terminal I1 of the phase synthesizer 27e to generate the original signal BS3. The original signal generator 24d is electrically connected to the second input terminal I2 of the phase synthesizer 27e to generate the original signal BS4.

The phase synthesis unit 23 is a processing unit that performs synthesis processing on a plurality of input signals IS8 to IS11 (signals IS12 to IS15) based on a plurality of original signals BS1 to BS4 to generate a plurality of radio signals RS1 to RS3. .. Further, the phase synthesizing unit 23 of the present embodiment generates a plurality of different radio signals RS1 to RS3 before and after the switch 26b is switched. Here, in the first connection state, the plurality of radio signals RS1 to RS3 generated by the phase synthesizing unit 23 are referred to as the plurality of first radio signals RS1 to RS3. Further, in the second connection state, the plurality of radio signals RS1 to RS3 generated by the phase synthesizing unit 23 are designated as the plurality of second radio signals RS1 to RS3.

The phase synthesizer 23 includes a phase synthesizer 27a, a phase synthesizer 27b, a phase synthesizer 27c, a phase synthesizer 27d, and a phase synthesizer 27e. In the following description, when the

phase synthesizers

27a, 27b, 27c, 27d, and 27e are described without distinction, they are simply referred to as the phase synthesizer 27. The phase synthesizer 27 is composed of, for example, a 90-degree hybrid unit (hybrid element). Since the basic operation of the phase synthesizer 27 is the same as the basic operation of the phase synthesizer 17 described in the column of "(2.2) Configuration of receiver 2 in (first embodiment)", the description thereof is omitted. To do.

The phase synthesizer 27d receives the input signal IS8 based on the original signal BS1 at the first input terminal I1 and the input signal IS9 based on the original signal BS2 at the second input terminal I2. The phase synthesizer 27d has a power value of 1 / √2 times that of the input signal IS8 and a signal having the same phase, and a signal having a power value of 1 / √2 times that of the input signal IS9 and a phase delay of 90 degrees. , Is added together, and the signal IS12 is output from the first output terminal O1. Further, the phase synthesizer 27d has a signal having a power value 1 / √2 times that of the input signal IS8 and a phase delay of 90 degrees, and a signal having a power value of 1 / √2 times that of the input signal IS9 and having the same phase. The signal IS13, which is the sum of the signal and the signal, is output from the second output terminal O2.

The phase synthesizer 27e receives the input signal IS10 based on the original signal BS3 at the first input terminal I1 and the input signal IS11 based on the original signal BS4 at the second input terminal I2. The phase synthesizer 27e has a power value of 1 / √2 times that of the input signal IS10 and a signal having the same phase, and a signal having a power value of 1 / √2 times that of the input signal IS11 and a phase delay of 90 degrees. , Is added together, and the signal IS14 is output from the first output terminal O1. Further, the phase synthesizer 27e has a signal having a power value of 1 / √2 times that of the input signal IS10 and a phase delay of 90 degrees, and a signal having a power value of 1 / √2 times that of the input signal IS11 and having the same phase. The signal IS15, which is the sum of the signal and the signal, is output from the second output terminal O2.

The phase synthesizer 27a outputs a radio signal RS1 having a power value 1 / √2 times that of the signal IS12 input to the second input terminal I2 and having the same phase from the second output terminal O2.

The phase synthesizer 27b receives the signal IS13 at the first input terminal I1 and the signal IS14 at the second input terminal I2. In the first connection state, the phase synthesizer 27b has a power value of 1 / √2 times that of the signal IS13 and a phase delayed by 90 degrees, and a power value of 1 / √2 times that of the signal IS14. The radio signal RS2, which is the sum of the signals having the same phase in the above, is output from the second output terminal O2. Further, in the second connection state, the phase synthesizer 27b has a power value of 1 / √2 times that of the signal IS13 and a signal having the same phase, and a power value of 1 / √2 times that of the signal IS14. The radio signal RS2, which is the sum of the signal whose phase is delayed by 90 degrees, is output from the first output terminal O1.

The phase synthesizer 27c outputs a radio signal RS3 having a power value 1 / √2 times that of the signal IS15 input to the first input terminal I1 and having the same phase from the first output terminal O1.

The change unit 25 is a processing unit that performs a change process for changing at least one element related to the process from the input of the plurality of original signals BS1 to BS4 to the transmission of the plurality of radio signals RS1 to RS3. The changing unit 25 of the present embodiment performs a process of controlling the switching unit 22 so as to switch the electrical connection state between the plurality of antennas 21 and the phase synthesizing unit 23 as at least a part of the changing process. Specifically, the changing unit 25 switches the electrical connection state between the antenna 21b and the phase synthesizer 27b by controlling the switch 26b to be switched. In the following description, it is assumed that the connection state between the antenna 21b and the phase synthesizer 27b is the first connection state until the change unit 25 performs the change processing. Further, it is assumed that the connection state between the antenna 21b and the phase synthesizer 27b is the second connection state after the change unit 25 performs the change processing. The change unit 25 performs the change process at a predetermined timing. The predetermined timing is, for example, a timing at which the phase synthesizer 23 outputs a plurality of radio signals RS1 to RS3, a constant timing set according to the interval at which the transmitter 4a transmits the radio signal, and the like.

(3) Estimating the Arrival Direction Next, a method in which the receiving system 1a estimates the arrival directions of the plurality of radio signals RS1 to RS3 will be described with reference to FIG. The matters explained in the column of "(3) Estimating the direction of arrival in (1st embodiment)" will be omitted as appropriate. As shown in FIG. 3, the complex propagation channel between the antenna 21a and the receiving antenna of the receiving system 1a is h4, the complex propagation channel between the antenna 21b and the receiving antenna is h5, and the complex propagation channel between the antenna 21c and the receiving antenna is between the antenna 21c and the receiving antenna. Let h6 be the complex propagation channel. Further, the distance between the antenna 21a and the antenna 21b and the distance between the antenna 21b and the antenna 21c are d2. Further, it is assumed that the receiving system 1a exists at a position of an angle θ2 with respect to the broadside direction of the array antenna composed of the antenna 21a, the antenna 21b, and the antenna 21c. First, a case where the receiving system 1a estimates the arrival directions of the plurality of first radio signals RS1 to RS3 will be described.

The propagation channels can be collectively expressed as Eq. (34).

The correlation matrix of this propagation channel can be expressed by Eq. (35).

By obtaining the correlation matrix R, the receiving system 1a can estimate the arrival directions of the plurality of first radio signals RS1 to RS3. The receiving system 1a obtains the correlation matrix R based on the information regarding the received signal strength.

Using the propagation channel of equation (34), the amplitudes of the original signals BS1, BS2, BS3, BS4 measured by the receiving system 1a can be expressed as equations (36) to (39).

It can be expressed as. Here, if the equation (40) is used, the apparent propagation channel can be expressed as the equations (41) to (44).

Since the method of obtaining the correlation matrix R based on the equations (41) to (44) is as described in the column of "(3) Estimating the direction of arrival in (first embodiment)", the description thereof will be omitted. Further, the method of obtaining the arrival directions of the plurality of first radio signals RS1 to RS3 by using a predetermined algorithm such as the MUSIC method for the correlation matrix R is also described in "(3) Arrival direction estimation in (1st embodiment)". Since it is as explained in the column, the description is omitted. In the following description, the arrival directions of the plurality of first radio signals RS1 to RS3 estimated by the receiving system 1a will be referred to as "first estimated directions".

Next, a case where the receiving system 1a estimates the arrival directions of the plurality of second radio signals RS1 to RS3 will be described. Using the propagation channel of equation (34), the amplitudes of the original signals BS1, BS2, BS3, BS4 measured by the receiving system 1a can be expressed by equations (45) to (48).

As shown by the formulas (45) to (48), the amplitudes of the original signals BS1, BS2, BS3, BS4 included in the plurality of first radio signals RS1 to RS3 and the amplitudes of the plurality of second radio signals RS1 to RS3 are included. The amplitudes of the original signals BS1, BS2, BS3, and BS4 are different. Therefore, the receiving system 1a can estimate the arrival direction different from the first estimation direction by obtaining the correlation matrix R using the equations (45) to (48). The description of a specific method for obtaining the correlation matrix R using the equations (45) to (48) will be omitted. In the following description, the arrival directions of the plurality of second radio signals RS1 to RS3 estimated by the receiving system 1a will be referred to as "second estimated directions".

The receiving system 1a that has received the plurality of first and second radio signals transmitted by the transmitter 4a receives the arrival directions of the plurality of radio signals RS1 to RS3 based on the first estimation direction and the second estimation direction (transmitter 4a). (Position direction) is estimated. For example, the receiving system 1a may estimate the arrival directions of the plurality of radio signals RS1 to RS3 by averaging the first estimation direction and the second estimation direction. The receiving system 1a that has received the plurality of first and second radio signals RS1 to RS3 transmitted by the transmitter 4a estimates the arrival directions of the radio signals RS1 to RS3 based on the plurality of estimation directions. Therefore, the accuracy in estimating the arrival direction of the radio signals RS1 to RS3 is higher than that of the existing receiving system that estimates the arrival direction of the radio signals RS1 to RS3 based on a plurality of radio signals RS1 to RS3 in one pattern. improves.

As described above, the transmitter 4a of the present embodiment includes a phase synthesizing unit 23, a plurality of antennas 21, and a changing unit 25. The phase synthesizing unit 23 performs synthesis processing on a plurality of input signals IS8 to IS11 (signals IS12 to IS15) based on the plurality of original signals BS1 to BS4, and generates a plurality of radio signals RS1 to RS3. The change unit 25 performs a change process for changing at least one element related to the process from the reception of the plurality of input signals IS8 to IS11 to the transmission of the plurality of radio signals RS1 to RS3. The phase synthesis unit 23 generates a plurality of first radio signals RS1 to RS3 as the plurality of radio signals RS1 to RS3 before the change processing by the change unit 25. Further, the phase synthesis unit 23 generates a plurality of second radio signals RS1 to RS3 as the plurality of radio signals RS1 to RS3 after the change processing by the change unit 25. The plurality of antennas 21 transmit a plurality of first radio signals RS1 to RS3 and a plurality of second radio signals RS1 to RS3. Since the transmitter 4a transmits a plurality of radio signals RS1 to RS3 having two or more patterns, the receiving system 1a estimates the direction of the transmitter 4a based on the plurality of radio signals RS1 to RS3 having two or more patterns. be able to. Therefore, the accuracy of estimation is improved as compared with the case where the receiving system 1a estimates the position direction of the transmitter 4a based on a plurality of radio signals of one pattern.

(Modification example)
The receiving system 1 (1a) and the transmitter 4 (4a) according to the modified example of the above embodiment are listed below. It should be noted that each configuration of the modification described below can be applied in combination with each configuration described in the above embodiment as appropriate.

(1) Modification 1
In the above embodiment, the changing unit 15 may perform a process of changing the setting related to the time when the plurality of antennas 11 receive the radio signal as at least a part of the changing process. The changing unit 15 changes the time length and reception timing when the plurality of antennas 11 receive the radio signal, so that the phase synthesizing unit 13 generates the combined signals SS1 to SS4 of two or more patterns. That is, as the patterns of the combined signals SS1 to SS4 increase, the value of | y1 | in the equation (3), the value of | y2 | in the equation (4), the value of | y3 | in the equation (5), and the equation (6). ) | Y4 | value pattern increases. Therefore, the estimation result of the arrival direction of the unvoiced signal estimated by the receiving system 1 increases, and the estimation accuracy is improved.

Further, in the above embodiment, the changing unit 25 performs a process of changing the setting related to the time when the plurality of antennas 21 transmit the plurality of radio signals RS1 to RS3 as at least a part of the changing process. You may. The change unit 25 changes the time length and transmission timing when the plurality of antennas 21 transmit the plurality of radio signals RS1 to RS3, so that the transmitter 4a transmits the plurality of radio signals RS1 to RS3 having two or more patterns. Send. Since the receiving system 1a estimates the direction of the transmitter 4a based on a plurality of radio signals RS1 to RS3 having two or more patterns, the estimation accuracy is improved.

(2) Modification example 2
In the above embodiment and the first modification, the phase synthesizing unit 13 may perform a phase shift process with respect to at least one of a plurality of input signals IS1 to IS3 (signals IS4 to IS7) in the synthesizing process. .. Further, the changing unit 15 may perform a process in which the phase synthesizing unit 13 changes the amount of phase shift of the input signals IS1 to IS3 (signals IS4 to IS7) in the synthesizing process as at least a part of the changing process. In the receiving system 1 of the above embodiment, the first composite signals SS1 to SS4 and the second composite signals SS1 to SS4 have different phase shifts of the input signals IS1 to IS3 (signals IS4 to IS7) by switching the switch 16b. Was being generated. The change unit 15 performs a change process in which the phase synthesizer 13 changes the amount of phase shift of the input signals IS1 to IS3 (signals IS4 to IS7) in the synthesis process, whereby the second composite signal SS1 similar to the above embodiment is performed. It becomes possible to generate ~ SS4. Since the receiving system 1 estimates the arrival direction of the radio signal (direction of the transmitter 4) based on the combined signals SS1 to SS4 of two or more patterns, the estimation accuracy is improved.

Further, in the above embodiment and the first modification, the phase synthesizing unit 23 performs a phase shift process with respect to at least one of the plurality of input signals IS8 to IS11 (signals IS12 to IS15) in the synthesizing process. May be good. Further, the changing unit 25 may perform a process in which the phase synthesizing unit 23 changes the amount of shifting the phase of the input signals IS8 to IS11 (signals IS12 to IS15) in the synthesizing process as at least a part of the changing process. In the transmitter 4a of the above embodiment, by switching the switch 26b, a plurality of first radio signals RS1 to RS3 and a plurality of second radio signals RS1 to RS3 in which the phase shifts of the input signals IS8 to IS11 (signals IS12 to IS15) are different from each other. The radio signals RS1 to RS3 were generated. The change unit 25 performs a change process for changing the amount of phase shift of the input signals IS8 to IS11 (signals IS12 to IS15) by the phase synthesizer 23 in the synthesis process, whereby a plurality of second units similar to those in the above embodiment are performed. It is possible to generate radio signals RS1 to RS3. Since the receiving system 1a estimates the direction of the transmitter 4a based on a plurality of radio signals RS1 to RS3 having two or more patterns, the estimation accuracy is improved.

(3) Modification 3
In the above-described embodiments and

modifications

1 and 2, the plurality of antennas 11 may be able to receive a plurality of radio signals having different frequency bands from each other as radio signals. When the radio signal complies with, for example, the BLE standard, the plurality of antennas 11 divides 2.400 [GHz] to 2.480 [GHz] into 2 [MHz] widths and divides each of the radio signals into 40 frequency bands. It may be receivable. Then, the change unit 15 may perform a process of switching the frequency band of the radio signal to be the target of the synthesis process as at least a part of the change process. When the changing unit 15 switches the frequency band of the radio signal to be combined, the phase combining unit 13 generates the combined signals SS1 to SS4 of two or more patterns. Since the receiving system 1 estimates the arrival direction of the radio signal (direction of the transmitter 4) based on the combined signals SS1 to SS4 of two or more patterns, the estimation accuracy is improved.

Further, in the above-described embodiments and

modifications

1 and 2, the plurality of antennas 21 may be capable of transmitting a plurality of radio signals RS1 to RS3 having different frequency bands from each other as the plurality of radio signals RS1 to RS3. Then, the changing unit 25 may perform a process of switching the frequency bands of the plurality of radio signals RS1 to RS3 transmitted by the plurality of antennas 21 as at least a part of the changing process. Before and after the change process by the change unit 25, the plurality of antennas 21 transmit a plurality of radio signals RS1 to RS3 having two or more patterns having different frequency bands from each other. Since the receiving system 1a estimates the direction of the transmitter 4a based on a plurality of radio signals RS1 to RS3 having two or more patterns, the estimation accuracy is improved.

(4) Modification example 4
Further, in the above-described embodiments and modifications 1 to 3, the plurality of antennas 11 may be able to receive a plurality of polarized waves different from each other as radio signals. Here, the plurality of polarized waves that are different from each other are, for example, horizontally polarized waves, vertically polarized waves, and circularly polarized waves. Then, the changing unit 15 performs a process of switching the type of polarization of the radio signal to be the target of the synthesis process as at least a part of the change process. The changing unit 15 switches the type of polarization of the radio signal to be combined, so that the plurality of antennas 11 receive the radio signals having different types of polarization. Then, the phase synthesizing unit 13 generates the combined signals SS1 to SS4 of two or more patterns. Since the receiving system 1 estimates the arrival direction of the radio signal (direction of the transmitter 4) based on the combined signals SS1 to SS4 of two or more patterns, the estimation accuracy is improved.

Further, in the above-described embodiments and modifications 1 to 2, the plurality of antennas 21 may be capable of transmitting a plurality of different polarized waves as a plurality of radio signals RS1 to RS3. Then, the changing unit 25 may perform a process of switching the polarization type of the plurality of radio signals RS1 to RS3 transmitted by the plurality of antennas 21 as at least a part of the changing process. Before and after the change process by the change unit 25, the plurality of antennas 21 transmit a plurality of radio signals RS1 to RS3 having two or more patterns having different types of polarization from each other. Since the receiving system 1a estimates the direction of the transmitter 4a based on a plurality of radio signals RS1 to RS3 having two or more patterns, the estimation accuracy is improved.

(5) Other Modifications In the present embodiment, the receiver 2 includes a switching unit 12, but the switching unit 12 is not essential. The receiver 2 may include at least a plurality of antennas 11, a phase synthesis unit 13, an output unit 14, and a change unit 15.

Further, in the present embodiment, the transmitter 4a includes the switching unit 22 and the original signal generating unit 24, but the switching unit 22 and the original signal generating unit 24 are not indispensable. The transmitter 4a may include at least a plurality of antennas 21, a phase synthesizing unit 23, and a changing unit 25.

Further, in the present embodiment, the receiving system 1 is realized by one system including the receiver 2 and the estimation unit 3, but may be realized by two or more systems. For example, the functions of the receiver 2 and the estimation unit 3 may be distributed in two or more systems. Further, at least one function of the receiver 2 and the estimation unit 3 may be distributed and provided in two or more systems. Further, the functions of the receiver 2 and the estimation unit 3 may be distributed to a plurality of devices. For example, the functions of the receiver 2 may be distributed and provided in two or more devices. Further, at least a part of the functions of the receiving system 1 may be realized by, for example, cloud computing.

(Reception method, program)
The above-described embodiment (including each modification) is only one of various embodiments. The above-described embodiment can be variously modified depending on the design and the like as long as the object of the present disclosure can be achieved. Further, the same function as that of the receiving system 1 may be realized by a receiving method, a program, a recording medium on which the program is recorded, or the like.

The receiving method according to the present embodiment includes a receiving step, a first phase synthesis step, a first output step, a change step, a second phase synthesis step, and a second output step. In the receiving step, the radio signal is received. In the first phase synthesis step, the plurality of input signals IS1 to IS3 based on the radio signal are combined, and the first synthetic signals SS1 to SS4 for estimating the arrival direction of the radio signal are generated. In the first output step, the first composite signals SS1 to SS4 generated in the first phase synthesis step are output. In the change step, at least one element related to the processing from the reception step to the first phase synthesis step is changed. In the second phase synthesis step, after the change step, the second composite signals SS1 to SS4 different from the first composite signals SS1 to SS4 generated in the first phase synthesis step are generated. In the second output step, the second composite signals SS1 to SS4 generated in the second phase synthesis step are output.

Further, the (computer) program according to the present embodiment includes one or more of the above-mentioned reception step, first phase synthesis step, first output step, change step, second phase synthesis step, and second output step. It is a program to be executed by the processor of.

The receiver 2, the receiving system 1, the transmitter 4a, and the executing body of the receiving method include a computer system. A computer system mainly consists of a processor and a memory as hardware. When the processor executes the program recorded in the memory of the computer system, the functions as the executing body of the receiver 2, the receiving system 1, the transmitter 4a, and the receiving method are realized. The program may be pre-recorded in the memory of the computer system. Further, the program may be provided through a telecommunication line, or may be recorded and provided on a recording medium such as a memory card, an optical disk, or a hard disk drive that can be read by a computer system. A processor in a computer system is composed of one or more electronic circuits including a semiconductor integrated circuit (IC) or a large scale integrated circuit (LSI). A plurality of electronic circuits may be integrated on one chip, or may be distributed on a plurality of chips. The plurality of chips may be integrated into one device, or may be distributed and provided in a plurality of devices.

(Summary)
As will be apparent from the above embodiments, the present disclosure includes the following first to eleventh aspects. In the following, reference numerals are given in parentheses only to clearly indicate the correspondence with the embodiments.

The receiver (2) according to the first aspect includes a plurality of antennas (11), a phase synthesis unit (13), an output unit (14), and a change unit (15). The plurality of antennas (11) receive the radio signal. The phase synthesizer (13) performs synthesis processing on a plurality of input signals (IS1 to IS3) based on radio signals input from the plurality of antennas (11), and synthesizes for estimating the arrival direction of the radio signal. Generate signals (SS1 to SS4). The output unit (14) outputs the combined signals (SS1 to SS4). The change unit (15) performs a change process for changing at least one element related to the process from the reception of the radio signal to the generation of the combined signal (SS1 to SS4). The phase synthesis unit (13) generates the first composite signal (SS1 to SS4) as the composite signal (SS1 to SS4) before the change processing by the change unit (15). Further, the phase synthesis unit (13) generates the second composite signal (SS1 to SS4) as the composite signal (SS1 to SS4) after the change processing by the change unit (15). The output unit (14) outputs the first composite signal (SS1 to SS4) and the second composite signal (SS1 to SS4).

According to this aspect, the receiver (2) changes a plurality of composites having different patterns by changing at least one element related to the process from the reception of the radio signal to the generation of the composite signals (SS1 to SS4). Generate signals (SS1 to SS4). Since the patterns of the combined signals (SS1 to SS4) for estimating the arrival direction of the radio signal (positional direction of the transmitter (4)) can be increased, the estimation accuracy of the arrival direction of the radio signal can be improved. ..

The receiver (2) according to the second aspect further includes a switching unit (12) in the first aspect. The switching unit (12) switches the electrical connection state between the plurality of antennas (11) and the phase synthesizing unit (13). The changing unit (15) performs a process of controlling the switching unit (12) so as to switch the electrical connection state between the plurality of antennas (11) and the phase synthesizing unit (13) as at least a part of the changing process. Do.

According to this aspect, the receiver (2) has a plurality of patterns having different patterns by switching the electrical connection state between the plurality of antennas (11) and the phase synthesizer (13) as a part of the change process. Generates synthetic signals (SS1 to SS4). Since the patterns of the combined signals (SS1 to SS4) for estimating the arrival direction of the radio signal (positional direction of the transmitter (4)) can be easily increased, the estimation accuracy of the arrival direction of the radio signal can be easily improved. Can be made to.

In the receiver (2) according to the third aspect, in the first aspect or the second aspect, the phase synthesis unit (13) has a plurality of input units. The plurality of input units are electrically connected to the plurality of antennas (11), and wireless signals are input. The number of the plurality of antennas (11) is equal to or less than the number of the plurality of input units.

According to this aspect, since the number of antennas (11) is less than or equal to the number of input units, the receiver (2) can be made compact.

In the receiver (2) according to the fourth aspect, in any one of the first to third aspects, the change unit (15) has a plurality of antennas (11) as at least a part of the change process. Performs processing to change the setting related to the time when receiving an unvoiced signal.

According to this aspect, the receiver (2) changes the settings related to the time (time length, reception timing) when receiving the radio signal, so that the receiver (2) has a plurality of composite signals (SS1 to SS4) having different patterns. To generate. Since the patterns of the combined signals (SS1 to SS4) for estimating the arrival direction of the radio signal (positional direction of the transmitter (4)) can be easily increased, the estimation accuracy of the arrival direction of the radio signal can be easily improved. Can be made to.

In the receiver (2) according to the fifth aspect, in any one of the first to fourth aspects, the phase synthesizer (13) is among the plurality of input signals (IS1 to IS3) in the synthesis process. The process of shifting at least one phase is performed. The change unit (15) performs a process of changing the amount of shifting the phase in the synthesis process as at least a part of the change process.

According to this aspect, the receiver (2) generates a plurality of composite signals (SS1 to SS4) having different patterns by changing the amount of shifting the phase in the synthesis process. That is, the patterns of the combined signals (SS1 to SS4) for estimating the arrival direction of the radio signal (positional direction of the transmitter (4)) can be easily increased. Therefore, the estimation accuracy of the arrival direction of the radio signal can be easily improved.

In the receiver (2) according to the sixth aspect, in any one of the first to fifth aspects, the plurality of antennas (11) can receive a plurality of radio signals having different frequency bands from each other as radio signals. Is. The change unit (15) performs a process of switching the frequency band of the radio signal to be the target of the synthesis process as at least a part of the change process.

According to this aspect, the receiver (2) generates a plurality of synthesized signals (SS1 to SS4) having different patterns by switching the frequency band of the radio signal to be the target of the synthesis processing. That is, the patterns of the combined signals (SS1 to SS4) for estimating the arrival direction of the radio signal (positional direction of the transmitter (4)) can be easily increased. Therefore, the estimation accuracy of the arrival direction of the radio signal can be easily improved.

In the receiver (2) according to the seventh aspect, in any one of the first to sixth aspects, each of the plurality of antennas (11) can receive a plurality of different polarized waves as radio signals. is there. The change unit (15) performs a process of switching the type of polarization of the radio signal to be the target of the synthesis process as at least a part of the change process.

According to this aspect, the receiver (2) generates a plurality of synthetic signals (SS1 to SS4) having different patterns by switching the type of polarization of the radio signal to be the target of the synthesis processing. That is, the patterns of the combined signals (SS1 to SS4) for estimating the arrival direction of the radio signal (positional direction of the transmitter (4)) can be easily increased. Therefore, the estimation accuracy of the arrival direction of the radio signal can be easily improved.

Note that the configurations according to the second to seventh aspects are not essential configurations for the receiver (2) and can be omitted as appropriate.

The receiving system (1) according to the eighth aspect includes a receiver (2) of any one of the first to seventh aspects and an estimation unit (3). The estimation unit (3) estimates the arrival direction of the radio signal based on the first composite signal (SS1 to SS4) and the second composite signal (SS1 to SS4) output from the receiver (2).

According to this aspect, the receiving system (1) changes a plurality of composites having different patterns by changing at least one element related to the process from the reception of the radio signal to the generation of the composite signals (SS1 to SS4). Generate signals (SS1 to SS4). Since the patterns of the combined signals (SS1 to SS4) for estimating the arrival direction of the radio signal (positional direction of the transmitter (4)) can be increased, the estimation accuracy of the arrival direction of the radio signal can be improved. ..

The transmitter (4a) according to the ninth aspect includes a phase synthesizing unit (23), a plurality of antennas (21), and a changing unit (25). The phase synthesizing unit (23) performs synthesis processing on a plurality of input signals (IS8 to IS11) based on a plurality of original signals (BS1 to BS4) to generate a plurality of radio signals (RS1 to RS3). The plurality of antennas (21) transmit a plurality of radio signals (RS1 to RS3). The change unit (25) performs a change process for changing at least one element related to the process from the reception of the plurality of original signals (BS1 to BS4) to the transmission of the plurality of radio signals (RS1 to RS3). The phase synthesizing unit (23) generates a plurality of first radio signals (RS1 to RS3) as a plurality of radio signals (RS1 to RS3) before the change processing by the change unit (25). Further, the phase synthesizing unit (23) generates a plurality of second radio signals (RS1 to RS3) as a plurality of radio signals (RS1 to RS3) after the change processing by the change unit (25). The plurality of antennas (21) output a plurality of first radio signals (RS1 to RS3) and a plurality of second radio signals (RS1 to RS3).

According to this aspect, the transmitter (4a) modifies at least one element related to the process from receiving a plurality of original signals (BS1 to BS4) to transmitting a plurality of radio signals (RS1 to RS3). Then, a plurality of radio signals (RS1 to RS3) having different patterns are transmitted. Since the patterns of the plurality of radio signals (RS1 to RS3) can be increased, the accuracy of estimating the position direction of the transmitter (4a) by the receiving system (1a) can be improved.

The receiving method according to the tenth aspect includes a receiving step, a first phase synthesis step, a first output step, a change step, a second phase synthesis step, and a second output step. In the receiving step, the radio signal is received. In the first phase synthesis step, a plurality of input signals (IS1 to IS3) based on the radio signal are combined, and the first composite signal (SS1 to SS4) for estimating the arrival direction of the radio signal is generated. To do. In the first output step, the first composite signals (SS1 to SS4) generated in the first phase synthesis step are output. In the change step, at least one element related to the processing from the reception step to the first phase synthesis step is changed. In the second phase synthesis step, after the change step, a second composite signal (SS1 to SS4) different from the first composite signal (SS1 to SS4) generated in the first phase synthesis step is generated. In the second output step, the second composite signals (SS1 to SS4) generated in the second phase synthesis step are output.

According to this aspect, a plurality of composite signals (SS1 to SS4) having different patterns are generated by changing at least one element related to the processing from the reception step to the first phase synthesis step. Since the patterns of the combined signals (SS1 to SS4) for estimating the arrival direction of the radio signal (positional direction of the transmitter (4)) can be increased, the estimation accuracy of the arrival direction of the radio signal can be improved. ..

The program according to the eleventh aspect causes one or more processors to execute the receiving method of the tenth aspect.

1 Reception system 2 Receiver 3 Estimator 4a Transmitter 11 Antenna 12 Switching unit 13 Phase synthesis unit 14 Output unit 15 Change unit 21 Antenna 22 Switching unit 23 Phase synthesis unit 25 Change unit BS1 to BS4 Original signal IS1 to IS3 Input signal IS8 ~ IS11 Input signal RS1 ~ RS3 Radio signal SS1 ~ SS4 Combined signal

Claims

With multiple antennas that receive radio signals,
A phase synthesizer that performs synthesis processing on a plurality of input signals based on the radio signals input from the plurality of antennas and generates a composite signal for estimating the arrival direction of the radio signals.
An output unit that outputs the combined signal and
A change unit that performs a change process that changes at least one element related to the process from the reception of the radio signal to the generation of the composite signal, and a change unit.
With
The phase synthesizer generates a first composite signal as the composite signal before the change process by the change section, and generates a second composite signal as the composite signal after the change process by the change section. ,
The output unit outputs the first composite signal and the second composite signal.
Receiver.
A switching unit for switching the electrical connection state between the plurality of antennas and the phase synthesizing unit is further provided.
The changing unit performs a process of controlling the switching unit so as to switch the electrical connection state between the plurality of antennas and the phase synthesizing unit as at least a part of the changing process.
The receiver according to claim 1.
The phase synthesizer has a plurality of input units that are electrically connected to the plurality of antennas and to which the radio signal is input.
The number of the plurality of antennas is equal to or less than the number of the plurality of input units.
The receiver according to claim 1 or 2.
As at least a part of the change process, the change unit performs a process of changing the setting related to the time when the plurality of antennas receive the radio signal.
The receiver according to any one of claims 1 to 3.
The phase synthesizing unit performs a process of shifting the phase of at least one of the plurality of input signals in the synthesizing process.
The change unit performs a process of changing the amount of shifting the phase in the synthesis process as at least a part of the change process.
The receiver according to any one of claims 1 to 4.
The plurality of antennas can receive a plurality of radio signals having different frequency bands from each other as the radio signals.
The change unit performs a process of switching the frequency band of the radio signal to be the target of the synthesis process as at least a part of the change process.
The receiver according to any one of claims 1 to 5.
Each of the plurality of antennas can receive a plurality of polarized waves different from each other as the radio signal.
The change unit performs a process of switching the type of polarization of the radio signal to be the target of the synthesis process as at least a part of the change process.
The receiver according to any one of claims 1 to 6.
The receiver according to any one of claims 1 to 7.
An estimation unit that estimates the arrival direction of the radio signal based on the first composite signal and the second composite signal output from the receiver.
To prepare
Receiving system.
A phase synthesizer that performs synthesis processing on multiple input signals based on multiple source signals and generates multiple radio signals,
A plurality of antennas that transmit the plurality of radio signals, and
A change unit that performs change processing that changes at least one element related to the process from the reception of the plurality of original signals to the transmission of the plurality of radio signals.
With
The phase synthesizing unit generates a plurality of first radio signals as the plurality of radio signals before the change processing by the change unit, and after the change process by the change unit, a plurality of the plurality of radio signals. Generates the second radio signal of
The plurality of antennas transmit the plurality of first radio signals and the plurality of second radio signals.
Transmitter.
The receiving step to receive the radio signal and
A first phase synthesis step of performing synthesis processing on a plurality of input signals based on the radio signal and generating a first composite signal for estimating the arrival direction of the radio signal.
A first output step for outputting the first composite signal generated in the first phase synthesis step, and a first output step.
A change step of changing at least one element related to the processing from the reception step to the first phase synthesis step, and a change step.
After the change step, a second phase synthesis step for generating a second composite signal different from the first composite signal generated in the first phase synthesis step,
A second output step for outputting the second composite signal generated in the second phase synthesis step, and a second output step.
Have,
Reception method.
A program for causing one or more processors to execute the receiving method according to claim 10.