JP7093927B2 - Wireless communication system, wireless communication method and wireless communication device - Google Patents

Description

The present invention relates to a wireless communication system, a wireless communication method and a wireless communication device.

Among the antennas that re-radiate radio waves in the direction of arrival of radio waves, the one with the simplest structure (Patent Document 1) is the Van Atta array. FIG. 11 shows a 4-element van-atter array. In the van-atter array, a plurality of antenna elements are arranged at equal intervals, and the antenna elements located symmetrically with respect to the center of the array are connected by a wire having an equal path length. When the plane wave incident on the van-atter array is received in the order of antenna elements # 4, # 3, # 2, # 1, the antenna elements # 1, # 2, # 3, # 1 pass through the connection and after a certain period of time elapses. It is re-radiated in the order of 4. At this time, the re-radiated wave strengthens each other in phase with respect to the arrival direction of the plane wave. Although FIG. 11 shows an example of a linear array, a planar array can be realized in the same manner.

The van atta array does not need to perform signal processing like a phased array in order to form a beam in the direction of arrival of radio waves. Therefore, beam formation in the direction of arrival of radio waves can be performed automatically and instantly, and the time from receiving radio waves to forming a beam in the direction of arrival is overwhelming compared to that of phased arrays. Short to.
Also, the van atta array does not require a signal processing unit or phase shifter like a phased array. Therefore, the structure of the array can be significantly simplified, and the size and cost of the array can be reduced. Further, since the signal processing and the phase shifter as described above are not required, the power required for them can be reduced and the power saving can be realized.

Wireless communication using the Van Atta Array is also being considered. (Non-Patent Document 1) introduces one in which an amplifier is added to the van-atter array connection to amplitude-modulate the incoming wave, and one in which an oscillator and a mixer are added to perform frequency modulation or phase modulation. Further, (Non-Patent Document 2) introduces a device in which a switch is added to the connection of a van-atter array to modulate it. 12, 13 and 14, respectively, show the wiring of the van-atter array with an amplifier, an oscillator and a mixer, and a switch added. These van-atter arrays can modulate the received radio waves and re-radiate them in the direction of their arrival, which means that the van-atter array can transmit information.

US Pat. No. 2,908,002

Vincent Fusco, and Neil Buchanan “Developments in retrodirective array technology” IET Microwaves, Antennas & Propagation, 2013, Vol. 7, Iss. 2, pp. 131-140 P. Chan, and V. Fusco “Bi-static 5.8 GHz RFID range enhancement using retrodirective techniques” Proceedings of the 41th Microwave Conference, 2011, pp. 976-979

However, van-atter arrays such as Non-Patent Document 1 and Non-Patent Document 2 are intended to receive only unmodulated continuous waves, modulate them, and re-radiate them in the direction of arrival. In other words, it is assumed that the van atta array can transmit information but cannot receive the information in one-way communication. Therefore, RFID (radio frequency identifier) and the like can be considered as the main usage scenes.

If the van-atter array can be applied to ordinary wireless communication devices such as wireless LAN access points and smartphones, the beam can be formed at high speed, downsized, cost-reduced, and power-saving compared to conventional ones. Is possible. However, a van-atter array capable of only one-way communication, such as Non-Patent Document 1 and Non-Patent Document 2, is insufficient for application to a normal wireless communication device, and in particular, bidirectional communication can be performed. Is considered to be an essential requirement.

In view of the above circumstances, it is an object of the present invention to provide a technique that enables two-way communication using a van-atter array.

One aspect of the present invention is an unmodulated continuous wave that transmits an unmodulated continuous wave that is an unmodulated radio wave having a frequency different from that of the data signal and a data transmitting unit that transmits a data signal that is a modulated radio wave. A first radio device including a wave transmitting unit and a receiving unit for receiving radio waves, and a second radio device for receiving the data signal and the unmodulated continuous wave are provided, and the second radio device is the same. 2 × N antenna elements from the first antenna element to the second (2 × N) antenna element that receive the data signal and the unmodulated continuous wave, a data signal filter that transmits radio waves of the frequency of the data signal, and A continuous wave filter that transmits radio waves with the frequency of the unmodulated continuous wave, a demodulator that demolishes the data signal that has passed through the data signal filter, and a modulation that modulates the unmodulated continuous wave that has passed through the continuous wave filter. The 2 × N antenna elements are located in an array, and the mth antenna element (m is an odd number of 1 or more (2 × N) or less) and the (m + 1) antenna element are The unmodulated continuous wave received by the m-th antenna element, which is an antenna element located at a position symmetrical with respect to the center of the array, is modulated by the modulation unit after passing through the continuous wave filter, and is modulated by the modulation unit. The unmodulated continuous wave radiated from the (m + 1) antenna element after being modulated and received by the (m + 1) antenna element is transmitted through the continuous wave filter and then modulated by the modulation unit, and the modulation unit is used. After being modulated by the m-th antenna element, the m-th antenna element receives the unmodulated continuous wave and then emits the unmodulated continuous wave after the (m + 1) antenna element is modulated. The m-th elapsed time is defined as the time until the m-th antenna element is generated, and the time from the reception of the unmodulated continuous wave by the (m + 1) antenna element to the emission of the unmodulated continuous wave after the m-th antenna element is modulated. With time as the (m + 1) elapsed time, all nth elapsed times are the same, and the first radio device receives the unmodulated continuous wave after being modulated by the second radio device, wireless communication. It is a system.

One aspect of the present invention is the wireless communication system described above, wherein the second wireless device receives the nth antenna element (n is an integer of 1 or more (2 × N) or less) as the data signal filter. The second radio device includes the nth data signal filter that transmits the radio wave of the frequency of the data signal, and the second radio device uses the radio wave of the unmodulated continuous wave frequency received by the nth antenna element as the continuous wave filter. The second radio device includes an nth continuous wave filter to be transmitted, and the second radio device includes, as the modulation unit, an nth modulation unit that modulates the unmodulated continuous wave transmitted through the nth continuous wave filter, and the demodulation unit is , The data signal that has passed through the nth data signal filter is demolished.

One aspect of the present invention is the wireless communication system, wherein the distance between the m-th antenna element and the (m + 1) antenna element is the unmodulated continuous wave in the space where the unmodulated continuous wave propagates. Is less than the wavelength of.

One aspect of the present invention is the above-mentioned wireless communication system, wherein the period in which the nth modulation unit modulates the unmodulated continuous wave is the nth modulation period, and all the nth modulation periods are the same.

One aspect of the present invention is the wireless communication method performed by the wireless communication system, wherein the first wireless device included in the wireless communication system has a data signal which is a modulated radio wave and a radio wave having a frequency different from that of the data signal. A transmission step of transmitting an unmodulated continuous wave, which is an unmodulated continuous wave radio wave, and a second wireless device included in the wireless communication system receive the data signal and the unmodulated continuous wave. 1 reception step, a separation step in which the second radio device separates the data signal from the unmodulated continuous wave, a demodulation step in which the second radio device demolishes the data signal, and the second radio device A modulation step that modulates the unmodulated continuous wave, a radiation step in which the second radio device emits the unmodulated continuous wave after being modulated in the modulation step, and a radiation step in which the first radio device emits the unmodulated continuous wave. It is a wireless communication method having a second reception step of receiving the radiated unmodulated continuous wave.

One aspect of the present invention is from a first antenna element that receives a data signal that is a modulated radio wave and an unmodulated continuous wave that is a radio wave having a frequency different from that of the data signal and is not modulated. 2 × N) 2 × N antenna elements of the antenna element and the nth data signal filter that transmits the data signal received by the nth antenna element (n is an integer of 1 or more (2 × N) or less). An nth continuous wave filter that transmits a radio wave having a frequency of the unmodulated continuous wave received by the nth antenna element, and an nth modulation unit that modulates the unmodulated continuous wave that has passed through the nth continuous wave filter. The 2 × N antenna elements are located in an array, and the mth antenna element (m is 1 or more (2). × N) The following odd number) and the (m + 1) th antenna element are antenna elements located symmetrically with respect to the center of the array, and the unmodulated continuous wave received by the mth antenna element is the first. After passing through the m continuous wave filter, it is modulated by the m-modulation unit, and after being modulated by the m-modulation unit, it is radiated from the (m + 1) antenna element and received by the (m + 1) antenna element. The modulated continuous wave is transmitted from the (m + 1) continuous wave filter, then modulated by the (m + 1) modulation unit, modulated by the (m + 1) modulation unit, and then emitted from the m-th antenna element. The time from when the m-th antenna element receives the unmodulated continuous wave to when the unmodulated continuous wave is emitted after the first (m + 1) antenna element is modulated is defined as the m-elapsed time, and the first (m + 1) th antenna element is used. ) The time from when the antenna element receives the unmodulated continuous wave to when the m-th antenna element is modulated to emit the unmodulated continuous wave is defined as the (m + 1) elapsed time, and all nth elapsed. The time is the same, it is a wireless device.

One aspect of the present invention is an unmodulated continuous wave that transmits an unmodulated continuous wave that is an unmodulated radio wave having a frequency different from that of the data signal and a data transmitting unit that transmits a data signal that is a modulated radio wave. A first radio device including a wave transmitting unit and a receiving unit that receives radio waves, and a second radio device that is a van-atter array that receives the data signal and the unmodulated continuous wave, said. The second wireless device demolishes the data signal filter that transmits the radio wave of the frequency of the data signal, the continuous wave filter that transmits the radio wave of the frequency of the unmodulated continuous wave, and the data signal that has passed through the data signal filter. The second radio device includes a demodulating unit and a modulation unit that modulates the unmodulated continuous wave that has passed through the continuous wave filter, and the second radio device radiates the unmodulated continuous wave after being modulated by the modulation unit. The first radio device is a radio communication system that receives the unmodulated continuous wave after being modulated by the second radio device.

One aspect of the present invention is the above-mentioned radio communication system, wherein the second radio device is located in an array shape, and the m-th antenna element (m is an odd number of 1 or more (2 × N) or less) and the above. The second (m + 1) antenna element includes an antenna element located at a position symmetrical with respect to the center of the array, and the second radio device uses the nth antenna element (n is 1 or more (2 × N) as the data signal filter. ) The nth data signal filter that transmits the radio wave of the frequency of the data signal received by the following integer) is provided, and the second radio device is the continuous wave filter, the unmodulated received by the nth antenna element. The second radio device includes an nth continuous wave filter that transmits a radio wave having a continuous wave frequency, and the second radio apparatus has, as the modulation unit, an nth modulation unit that modulates the unmodulated continuous wave that has passed through the nth continuous wave filter. The demodulator unit democratizes the data signal that has passed through the nth data signal filter, and the unmodulated continuous wave received by the mth antenna element passes through the mth continuous wave filter and then passes through the mth continuous wave filter. The unmodulated continuous wave that is modulated by the m-th modulator, radiated from the (m + 1) antenna element after being modulated by the m-modulator, and received by the (m + 1) antenna element is the (m + 1) th (m + 1) continuous wave. ) After passing through the continuous wave filter, it is modulated by the (m + 1) modulation unit, and after being modulated by the (m + 1) modulation unit, it is radiated from the mth antenna element, and the mth antenna element is unmodulated continuously. The time from the reception of the wave to the emission of the unmodulated continuous wave after the first (m + 1) antenna element is modulated is defined as the m-elapsed time, and the first (m + 1) antenna element is the unmodulated continuous wave. The nth elapsed time is the same, where the time from the reception of the mth antenna element to the emission of the unmodulated continuous wave after the mth antenna element is modulated is defined as the (m + 1) elapsed time.

INDUSTRIAL APPLICABILITY According to the present invention, it becomes possible to provide a technique that enables two-way communication using a van-atter array.

The figure which shows an example of the system configuration of the wireless communication system 1 of an embodiment. The figure which shows an example of the frequency spectrum of a data signal and an unmodulated continuous wave in an embodiment. The figure which shows an example of the functional structure of the 2nd wireless device 20 in embodiment. The figure which shows an example of the transmission spectrum of the data signal filter 203 and the transmission spectrum of a continuous wave filter 204 in an embodiment. The figure which shows an example of the time change of the intensity of the unmodulated continuous wave in the 1st antenna element 211-1 and the 2nd antenna element 201-2 in an embodiment. The figure which shows an example of the 1st modulation signal and the 2nd modulation signal when the phase difference between the 1st modulation signal and the 2nd modulation signal is 2πL / λ <2π. The figure which shows an example of the 1st modulation signal and the 2nd modulation signal when the phase difference between the 1st modulation signal and the 2nd modulation signal is 2πL / λ ≧ 2π. The figure which shows an example of the frequency spectrum of the output wave in an embodiment. The figure which shows an example of the functional structure of the 2nd wireless device 20a in embodiment. The flowchart which shows an example of the processing flow in the wireless communication system 1 of embodiment. The figure explaining the conventional 4-element van atta array. FIG. 1 illustrates a conventional antenna with an amplifier, oscillator and mixer, and a switch added to the van-atter array connection. FIG. 2 illustrates a conventional antenna with an amplifier, oscillator and mixer, and a switch added to the van-atter array connection. FIG. 3 illustrates a conventional antenna with an amplifier, oscillator and mixer, and a switch added to the van-atter array connection.

(First Embodiment)
FIG. 1 is a diagram showing an example of a system configuration of the wireless communication system 1 of the embodiment. The wireless communication system 1 includes a first wireless device 10 and a second wireless device 20.

The first wireless device 10 includes a CPU (Central Processing Unit), a memory, an auxiliary storage device, and the like connected by a bus, and functions as a device by executing a program. The first wireless device 10 functions as a device including a data transmission unit 101, an unmodulated wave transmission unit 102, and a reception unit 103 by executing a program.

The data transmission unit 101 transmits a data signal. The data signal is a modulated radio wave having a frequency f1_i, and is a radio wave indicating predetermined information.
The unmodulated wave transmission unit 102 transmits an unmodulated continuous wave. The unmodulated continuous wave is an unmodulated radio wave having a frequency f2_i and is a continuous wave. The frequency of the data signal is different from the frequency of the unmodulated continuous wave.
The receiving unit 103 receives radio waves.

FIG. 2 is a diagram showing an example of the frequency spectrum of the data signal and the unmodulated continuous wave in the embodiment.
FIG. 2 shows the frequency spectrum Wi1 of the data signal and the frequency spectrum Wi2 of the unmodulated continuous wave. A data signal is a modulated signal and an unmodulated continuous wave is an unmodulated signal. Therefore, the half-value width of the frequency spectrum Wi1 of the data signal is wider than the half-value width of the frequency spectrum Wi2 of the unmodulated continuous wave. The frequency spectrum Wi1 of the data signal and the frequency spectrum Wi2 of the unmodulated continuous wave do not overlap on the frequency axis.

Returning to the description of FIG.
The second radio device 20 receives the data signal and the unmodulated continuous wave, and outputs the output wave. The output wave is a radio wave in which the unmodulated continuous wave received by the second radio device 20 is modulated by the second radio device 20.

FIG. 3 is a diagram showing an example of the functional configuration of the second wireless device 20 in the embodiment.
The second wireless device 20 includes a CPU (Central Processing Unit), a memory, an auxiliary storage device, and the like connected by a bus, and executes a program. The second radio device 20 includes the first antenna element 201-1, the second antenna element 201-2, the first circulator 202-1, the second circulator 202-2, and the first data signal filter by executing the program. 203-1, the second data signal filter 203-2, the first continuous wave filter 204-1, the second continuous wave filter 204-2, the first modulation unit 205-1, and the second modulation unit 205-. 2 functions as a device including the demodulation unit 206.

The first antenna element 21-1 and the second antenna element 201-2 receive a data signal and an unmodulated continuous wave. The first antenna element 21-1 and the second antenna element 201-2 transmit an output wave.

The first circulator 202-1 and the second circulator 202-2 are circulators for electronic components. The first circulator 202-1 and the second circulator 202-2 include three or more ports including three ports, a first port, a second port, and a third port. The connection destinations of the first port, the second port, and the third port are different from each other.

Specifically, the first terminal of the first circulator 202-1 is connected to the first antenna element 201-1. The second terminal of the first circulator 202-1 is connected to the first continuous wave filter 204-1 and the first data signal filter 203-1. The third terminal of the first circulator 202-1 is connected to the second modulation unit 205-2.

The first terminal of the second circulator 202-2 is connected to the second antenna element 201-2. The second terminal of the second circulator 202-2 is connected to the second continuous wave filter 204-2 and the second data signal filter 203-2. The third terminal of the second circulator 202-2 is connected to the first modulation unit 205-1.

The first data signal filter 203-1 and the second data signal filter 203-2 are filters that transmit data signals and do not transmit unmodulated continuous waves. The first data signal filter 203-1 is connected to the first circulator 202-1 and the demodulation unit 206. The second data signal filter 203-2 is connected to the second circulator 202-2 and the demodulation unit 206.

The first data signal filter 203-1 and the second data signal filter 203-2 may be any filter as long as they are filters that allow data signals to pass through and do not allow unmodulated continuous waves to pass through. The first data signal filter 203-1 and the second data signal filter 203-2 may be, for example, bandpass filters having substantially the same frequency band as the frequency band of the data signal. The first data signal filter 203-1 and the second data signal filter 203-2 may be, for example, low-pass filters that do not transmit unmodulated continuous waves but transmit data signals.

The first continuous wave filter 204-1 and the second continuous wave filter 204-2 are filters that transmit unmodulated continuous waves and do not transmit data signals. The first continuous wave filter 204-1 is connected to the first circulator 202-1 and the first modulation unit 205-1. The second continuous wave filter 204-2 is connected to the second circulator 202-2 and the second modulation unit 205-2.

The first continuous wave filter 204-1 and the second continuous wave filter 204-2 may be any filter as long as they transmit unmodulated continuous waves and do not transmit data signals. The first continuous wave filter 204-1 and the second continuous wave filter 204-2 may be, for example, bandpass filters having substantially the same frequency band as the frequency band of the unmodulated continuous wave. The first continuous wave filter 204-1 and the second continuous wave filter 204-2 may be, for example, high-pass filters that transmit unmodulated continuous waves without transmitting data signals.

FIG. 4 shows the transmission spectra of the first data signal filter 203-1 and the second data signal filter 203-2 and the transmission spectra of the first continuous wave filter 204-1 and the second continuous wave filter 204-2 in the embodiment. It is a figure which shows an example of.

The transmission spectrum S1 of the first data signal filter 203-1 and the second data signal filter 203-2 is a transmission spectrum that allows the data signal to pass through and does not allow the unmodulated continuous wave to pass through. The transmission spectrum S2 of the first continuous wave filter 204-1 and the second continuous wave filter 204-2 is a transmission spectrum that allows unmodulated continuous waves to pass through and does not allow data signals to pass through.

Returning to the description of FIG.
The first modulation unit 205-1 and the second modulation unit 205-2 modulate the unmodulated continuous wave at the same time. More specifically, the first modulation unit 205-1 modulates the unmodulated continuous wave transmitted through the first continuous wave filter 204-1, and the second modulation unit 205-2 is the second continuous wave filter 204-. Modulates an unmodulated continuous wave that has passed through 2. The time when the first modulation unit 205-1 modulates the unmodulated continuous wave transmitted through the first continuous wave filter 204-1 and the unmodulated continuous wave transmitted by the second modulation unit 205-2 through the second continuous wave filter 204-2. The time to modulate the wave is the same time.

The first modulation unit 205-1 is connected to the first continuous wave filter 204-1 and the third terminal of the second circulator 202-2. The second modulation unit 205-2 is connected to the second continuous wave filter 204-2 and the third terminal of the first circulator 202-1.

The demodulation unit 206 acquires a data signal that has passed through the first data signal filter 203-1 or the second data signal filter 203-2, and demodulates the acquired data signal. The demodulation unit 206 is connected to the first data signal filter 203-1 and the second data signal filter 203-2. The demodulation unit 206 outputs the demodulated data signal to a predetermined output destination (not shown).

(Wiring length)
Here, the length of the wiring between each functional unit included in the second wireless device 20 will be described. In the second wireless device 20, the length of the wiring from the first antenna element 201-1 to the second circulator 202-2 is the same as the length of the wiring from the second antenna element 201-2 to the first circulator 202-1. Is. More specifically, the path length of the first path and the path length of the second path are the same. The first path is a path from the first antenna element 211-1 to the second circulator 202-2 via the first circulator 202-1, the first continuous wave filter 204-1 and the first modulation unit 205-1. Is. The second path is a path from the second antenna element 201-2 to the first circulator 202-1 via the second circulator 202-2, the second continuous wave filter 204-2, and the second modulation unit 205-2. Is.

Further, the length of the wiring between the first circulator 202-1 and the first antenna element 201-1 and the length of the wiring between the second circulator 202-2 and the second antenna element 201-2 are the same. be. Hereinafter, the length of the wiring between the first circulator 202-1 and the first antenna element 201-1 is referred to as the first antenna wiring length. Hereinafter, the length of the wiring between the second circulator 202-2 and the second antenna element 201-2 is referred to as the second antenna wiring length.

Further, the length of the wiring from the first antenna element 201-1 to the first modulation unit 205-1 is the same as the length of the wiring from the second antenna element 201-2 to the second modulation unit 205-2.

(About the propagation path)
The path of propagation of the data signal received by the second radio device 20 and the unmodulated continuous wave in the second radio device 20 will be described.

First, the propagation path of the data signal and the unmodulated continuous wave received by the first antenna element 2011-1 will be described. The data signal and the unmodulated continuous wave received by the first antenna element 21-1 propagate to the first circulator 202-1. The data signal and unmodulated continuous wave propagated to the first circulator 202-1 propagate from the first circulator 202-1 to the first data signal filter 203-1 and the first continuous wave filter 204-1.

Of the data signal and unmodulated continuous wave propagated to the first continuous wave filter 204-1, only the unmodulated continuous wave passes through the first continuous wave filter 204-1. The unmodulated continuous wave transmitted through the first continuous wave filter 204-1 propagates from the first continuous wave filter 204-1 to the first modulation unit 205-1.

The unmodulated continuous wave propagating to the first modulation unit 205-1 is modulated by the first modulation unit 205-1 for a predetermined period (hereinafter referred to as "first modulation period"). Hereinafter, the unmodulated continuous wave modulated by the first modulation unit 205-1 is referred to as a first modulation signal. The first modulated signal is a radio wave.

The first modulation signal propagates from the first modulation unit 205-1 to the second circulator 202-2. The first modulation signal propagated to the second circulator 202-2 propagates from the second circulator 202-2 to the second antenna element 201-2 and is radiated from the second antenna element 201-2.

On the other hand, of the data signal propagated to the first data signal filter 203-1 and the unmodulated continuous wave, only the data signal passes through the first data signal filter 203-1. The data signal transmitted through the first data signal filter 203-1 propagates from the first data signal filter 203-1 to the demodulation unit 206. The data signal propagated to the demodulation unit 206 is demodulated by the demodulation unit 206.

Next, the propagation path of the data signal and the unmodulated continuous wave received by the second antenna element 201-2 will be described.

The data signal and unmodulated continuous wave received by the second antenna element 201-2 propagate to the second circulator 202-2. The data signal and unmodulated continuous wave propagated to the second circulator 202-2 propagate from the second circulator 202-2 to the second data signal filter 203-2 and the second continuous wave filter 204-2.

Of the data signal and unmodulated continuous wave propagated to the second continuous wave filter 204-2, only the unmodulated continuous wave passes through the second continuous wave filter 204-2. The unmodulated continuous wave transmitted through the second continuous wave filter 204-2 propagates from the second continuous wave filter 204-2 to the second modulation unit 205-2.

The unmodulated continuous wave propagating to the second modulation unit 205-2 is modulated by the second modulation unit 205-2 for a predetermined period (hereinafter referred to as “second modulation period”). The second modulation period is a period in which the start time of the period and the length of the period are the same as the first modulation period. Hereinafter, the unmodulated continuous wave modulated by the second modulation unit 205-2 is referred to as a second modulation signal. The second modulated signal is a radio wave. Hereinafter, when the first modulation period and the second modulation period are not distinguished, it is referred to as a modulation period.

The second modulation signal propagates from the second modulation unit 205-2 to the first circulator 202-1. The second modulation signal propagated to the first circulator 202-1 propagates from the first circulator 202-1 to the first antenna element 201-1 and is radiated from the first antenna element 201-1.

The radio wave radiated from the first antenna element 21-1 and the radio wave radiated from the second antenna element 201-2 are output waves output by the second radio device 20.

(About output wave)
The output wave output by the second radio device 20 will be described by describing the radio wave radiated from the first antenna element 21-1 and the radio wave radiated from the second antenna element 201-2.
Hereinafter, it is assumed that the data signal and the unmodulated continuous wave are radiated from the light source at time t0. The light source is the first wireless device 10.

The time when the data signal and the unmodulated continuous wave radiated from the light source at time t0 reach the first antenna element 211-1 is defined as the first arrival time t_in_1. The time when the data signal and the unmodulated continuous wave radiated from the light source at time t0 reach the second antenna element 201-2 is defined as the second arrival time t_in_2.

When the first optical path length and the second optical path length are equal, the first arrival time t_in_1 and the second arrival time t_in_1 are the same. The first optical path length is the distance between the light source of the data signal and the unmodulated continuous wave and the first antenna element 21-1. The second optical path length is the distance between the light source of the data signal and the unmodulated continuous wave and the second antenna element 201-2.
On the other hand, when the first optical path length and the second optical path length are different, the first arrival time t_in_1 and the second arrival time t_in_1 are different.

Since the path length of the first path and the path length of the second path are the same and the first antenna wiring length and the second antenna wiring length are the same, the first arrival time t_in_1 and the second arrival time t_in_1 are different. In some cases, the first modulated signal and the second modulated signal differ in the time at which they start to be radiated. Specifically, when the first arrival time t_in_1 is later by the time Δt than the second arrival time t_in_2, the first radiation time t_out_1 is a time Δt earlier than the second radiation time t_out_2. The first radiation time t_out_1 is the time when the first modulation signal starts to be emitted from the first antenna element 211-1. The second radiation time t_out_2 is the time when the second modulation signal starts to be emitted from the second antenna element 201-2.

In this way, since the path length of the first path and the path length of the second path are the same and the first antenna wiring length and the second antenna wiring length are the same, the first arrival time t_in_1 to the second arrival time The value obtained by subtracting t_in_2 is equal to the value obtained by subtracting the first radiation time t_out_1 from the second radiation time t_out_2. Therefore, the second radio device 20 is a van atta array.

FIG. 5 is a diagram showing an example of a time change of the intensity of the unmodulated continuous wave in the first antenna element 21-1 and a time change of the intensity of the unmodulated continuous wave in the second antenna element 201-2. ..

FIG. 5 shows that the time when the unmodulated continuous wave arrives at the first antenna element 201-1 is later than the time when the unmodulated continuous wave arrives at the second antenna element 201-2 by L / c. L is the difference between the first optical path length and the second optical path length. Hereinafter, L is referred to as an optical path difference. c represents the speed of light. The difference in L / c means that there is a phase difference of 2πL / λ. λ is the wavelength of the unmodulated continuous wave in the space in which the unmodulated continuous wave propagates. More specifically, λ is the dimension of length, and the length is a value obtained by dividing λ0 by the dielectric constant of the space in which the unmodulated continuous wave propagates, with the wavelength in vacuum as λ0.

FIG. 6 is a diagram showing an example of a time change in the intensity of the first modulated signal in the first antenna element 211-1 and a time change in the intensity of the second modulated signal in the second antenna element 201-2. .. More specifically, FIG. 6 shows the first in the first antenna element 21-1 when the phase difference between the first modulated signal and the second modulated signal is 2πL / λ <2π, that is, the path difference is L <λ. It is a figure which shows an example of the modulation signal and the 2nd modulation signal in the 2nd antenna element 201-2.

FIG. 6 shows that the time when the first modulated signal starts to be radiated by the first antenna element 21-1 is L / c earlier than the time when the second modulated signal starts to be radiated by the second antenna element 201-2. ..

Since the first arrival time is L / c later than the second arrival time, the first radiation time is L / c earlier than the second radiation time.

FIG. 6 shows an example of the result of modulation during the modulation period. Specifically, FIG. 6 shows an example of a first modulated signal which is an unmodulated continuous wave whose amplitude is amplified by the first modulation unit 205-1 during the modulation period. FIG. 6 shows an example of a second modulated signal which is an unmodulated continuous wave whose amplitude is amplified by the second modulation unit 205-2 during the modulation period.

In FIG. 6, the period P1 and the period P2 are periods in which the phase changes of the first modulation signal and the second modulation signal are the same. Further, in FIG. 6, the phase difference between the first modulation signal and the second modulation signal in the period P1 and the period P2 is 2πL / λ. In FIG. 6, the time difference between the time when the phase of the first modulated signal is a predetermined phase ξ (ξ is an arbitrary value) and the time when the phase of the second modulated signal is the phase ξ in the period P1 and the period P2 is L. / C. Hereinafter, the time difference between the time when the phase of the first modulated signal is the phase ξ and the time when the phase of the second modulated signal is the phase ξ in the period P1 and the period P2 is referred to as the time difference between the period P1 and the period P2. FIG. 6 shows that the first arrival time is delayed by L / c from the second arrival time.

In FIG. 6, the first arrival time is later than the second arrival time by L / c, and the time difference between the period P1 and the period P2 is L / c. Therefore, the first modulation signal of the period P1 and the second modulation signal of the period P2 strengthen each other in the same phase in the direction propagating to the first radio device 10.

FIG. 7 is a diagram showing an example of a first modulated signal and a second modulated signal when the phase difference between the first modulated signal and the second modulated signal is 2πL / λ ≧ 2π, that is, the path difference is L ≧ λ. ..
In FIG. 7, the period P1 and the period P2 are periods in which the phase changes of the first modulation signal and the second modulation signal are the same. Further, in FIG. 7, the phase difference between the first modulated signal and the second modulated signal in the period P1 and the period P2 is θ. However, θ is a value of 0 or more and less than 2π, and satisfies the relationship between the optical path difference L and the wavelength λ and 2πL / λ = θ + 2hπ (h is a positive integer). Therefore, the time difference between the time when the phase of the first modulated signal is the phase ξ and the time when the phase of the second modulated signal is the phase ξ in the period P1 and the period P2 is λθ / 2πc.

In FIG. 7, the first arrival time is later than the second arrival time by L / c, and the time difference between the period P1 and the period P2 is λθ / 2πc. Therefore, the first modulation signal of the period P1 and the second modulation signal of the period P2 do not strengthen each other in the same phase in the direction propagating to the first radio device 10.

(About the distance between the 1st antenna element and the 2nd antenna element)
Here, the distance between the first antenna element 21-1 and the second antenna element 201-2 will be described. Hereinafter, the distance between the first antenna element 21-1 and the second antenna element 201-2 is referred to as the distance d between the first antennas.

If the optical path difference L is less than the wavelength (that is, L <λ), the first modulation signal of the period P1 and the second modulation signal of the period P2 are in phase in the direction of propagation to the first radio device 10. However, if the optical path difference L is equal to or greater than the wavelength (that is, L ≧ λ), the first modulation signal of the period P1 and the second modulation signal of the period P2 are not in phase in the direction of propagation to the first radio device 10. Therefore, when the distance d between the first antennas is less than the wavelength, the intensity of the output wave is stronger in the direction propagating to the first radio device 10 than when the distance d between the first antennas is not more than the wavelength.
When the distance d between the first antennas is less than the wavelength λ / 2, the generation of great tein gloves is suppressed.

FIG. 8 is a diagram showing an example of the frequency spectrum of the output wave in the embodiment. FIG. 8 shows the frequency spectrum Wi3 of the output wave. The output wave is a radio wave in which an unmodulated continuous wave is modulated. Therefore, the frequency spectrum Wi3 of the output wave is centered on the center of the frequency spectrum Wi2 of the unmodulated continuous wave, and has a half-value width wider than the half-value width of the frequency spectrum Wi2 of the unmodulated continuous wave. This is the end of the description of FIG.

The second radio device 20 configured in this way includes a first continuous wave filter 204-1, a second continuous wave filter 204-2, a first data signal filter 203-1 and a second data signal filter 203-. 2, the first modulation unit 205-1, the second modulation unit 205-2, and the demodulation unit 206 are provided, the path length of the first path and the path length of the second path are the same, and the first antenna wiring length. And the second antenna wiring length are the same, and the first modulation period and the second modulation period are the same. Therefore, the second radio device 20 configured in this way can receive a data signal and transmit an output wave even though it is a van-atter array.

The wireless communication system 1 configured in this way includes a first wireless device 10 and a second wireless device 20. Therefore, the wireless communication system 1 configured in this way is capable of bidirectional communication using a van-atter array. Specifically, the wireless communication system 1 configured in this way is capable of frequency division duplex (FDD) using a van-atter array.

(When the second wireless device 20 includes a plurality of antenna elements of 4 or more)
Hereinafter, when the first antenna element 21-1 and the second antenna element 201-2 are not distinguished, they are referred to as an antenna element 201. Hereinafter, when the first circulator 202-1 and the second circulator 202-2 in the embodiment are not distinguished, they are referred to as circulator 202. Hereinafter, when the first data signal filter 203-1 and the second data signal filter 203-2 in the embodiment are not distinguished, the data signal filter 203 is referred to. Hereinafter, when the first continuous wave filter 204-1 and the second continuous wave filter 204-2 in the embodiment are not distinguished, the term is referred to as a continuous wave filter 204. Hereinafter, when the first modulation unit 205-1 and the second modulation unit 205-2 are not distinguished in the embodiment, they are referred to as a modulation unit 205.

The second wireless device 20 in the embodiment does not necessarily have to include only two antenna elements 201, that is, the first antenna element 211-1 and the second antenna element 201-2. The second wireless device 20 in the embodiment may include an even number of antenna elements 201 of 4 or more. Hereinafter, the second radio device 20 including 2 × N antenna elements 201 (N is an integer of 1 or more) is referred to as a second radio device 20a.

The second wireless device 20a includes a CPU (Central Processing Unit), a memory, an auxiliary storage device, and the like connected by a bus, and executes a program. The second radio device 20a has 2 × N antenna elements 201, 2 × N circulators 202, 2 × N data signal filters 203, and 2 × N continuous wave filters 204 by executing a program. And functions as a device including 2 × N modulation units 205 and a demodulation unit 206a.

(Second radio device with N = 2)
First, the second wireless device 20a will be described by taking the second wireless device 20a in the case of N = 2 as a specific example.

FIG. 9 is a diagram showing an example of the functional configuration of the second wireless device 20a in the embodiment.
The second wireless device 20a includes, as a plurality of antenna elements 201, a first antenna element 211-1, a second antenna element 201-2, a third antenna element 201-3, and a fourth antenna element 201-4. Be prepared.
The second radio device 20a includes a first circulator 202-1, a second circulator 202-2, a third circulator 202-3, and a fourth circulator 202-4 as a plurality of circulators 202.

The second radio device 20a has, as a plurality of data signal filters 203, a first data signal filter 203-1, a second data signal filter 203-2, a third data signal filter 203-3, and a fourth data signal filter. It is equipped with 203-4.
The second radio device 20a has, as a plurality of continuous wave filters 204, a first continuous wave filter 204-1, a second continuous wave filter 204-2, a third continuous wave filter 204-3, and a fourth continuous wave filter. It is equipped with 204-4.

The second radio device 20a includes, as a plurality of modulation units 205, a first modulation unit 205-1, a second modulation unit 205-2, a third modulation unit 205-3, and a fourth modulation unit 205-4. Be prepared.

The first antenna element 211-1, the second antenna element 201-2, the third antenna element 201-3, and the fourth antenna element 201-4 are located in an array. The first antenna element 21-1 and the second antenna element 201-2 are located symmetrically with respect to the center of the array. The third antenna element 201-3 and the fourth antenna element 201-4 are located symmetrically with respect to the center of the array.
Hereinafter, those having the same functions as those in the second wireless device 20 are designated by the same reference numerals as those in FIG. 3, and the description thereof will be omitted.

The third antenna element 201-3 and the fourth antenna element 201-4 receive the data signal and the unmodulated continuous wave. The third antenna element 201-3 and the fourth antenna element 201-4 transmit an output wave.

The third circulator 202-3 and the fourth circulator 202-4 are circulators for electronic components. The third circulator 202-3 and the fourth circulator 202-4 include three or more ports including three ports, a first port, a second port, and a third port. The connection destinations of the first port, the second port, and the third port are different from each other.

Specifically, the first terminal of the third circulator 202-3 is connected to the third antenna element 201-3. The second terminal of the third circulator 202-3 is connected to the third continuous wave filter 204-3 and the third data signal filter 203-3. The third terminal of the third circulator 202-3 is connected to the fourth modulation unit 205-4.

The first terminal of the fourth circulator 202-4 is connected to the fourth antenna element 201-4. The second terminal of the fourth circulator 202-4 is connected to the fourth continuous wave filter 204-4 and the fourth data signal filter 203-4. The third terminal of the fourth circulator 202-4 is connected to the third modulation unit 205-3.

The third data signal filter 203-3 and the fourth data signal filter 203-4 are filters that transmit data signals and do not transmit unmodulated continuous waves. The third data signal filter 203-3 is connected to the third circulator 202-3 and the demodulation unit 206a. The fourth data signal filter 203-4 is connected to the fourth circulator 202-4 and the demodulation unit 206a.

The third data signal filter 203-3 and the fourth data signal filter 203-4 may be any filter as long as they are filters that transmit the data signal and do not transmit the unmodulated continuous wave. The third data signal filter 203-3 and the fourth data signal filter 203-4 may be, for example, bandpass filters having substantially the same frequency band as the frequency band of the data signal. The third data signal filter 203-3 and the fourth data signal filter 203-4 may be, for example, low-pass filters that allow data signals to pass through without transmitting unmodulated continuous waves.

The third continuous wave filter 204-3 and the fourth continuous wave filter 204-4 are filters that transmit unmodulated continuous waves and do not transmit data signals. The third continuous wave filter 204-3 is connected to the third circulator 202-3 and the third modulation unit 205-3. The fourth continuous wave filter 204-4 is connected to the fourth circulator 202-4 and the fourth modulation unit 205-4.

The third continuous wave filter 204-3 and the fourth continuous wave filter 204-4 may be any filter as long as they transmit unmodulated continuous waves and do not transmit data signals. The third continuous wave filter 204-3 and the fourth continuous wave filter 204-4 may be, for example, bandpass filters having substantially the same frequency band as the frequency band of the unmodulated continuous wave. The third continuous wave filter 204-3 and the fourth continuous wave filter 204-4 may be, for example, high-pass filters that transmit unmodulated continuous waves without transmitting data signals.

The third modulation unit 205-3 and the fourth modulation unit 205-4 modulate the unmodulated continuous wave at the same time. More specifically, the third modulation unit 205-3 modulates the unmodulated continuous wave transmitted through the third continuous wave filter 204-3, and the fourth modulation unit 205-4 uses the fourth continuous wave filter 204-. Modulates an unmodulated continuous wave that has passed through 4. The time when the third modulation unit 205-3 modulates the unmodulated continuous wave transmitted through the third continuous wave filter 204-3 and the unmodulated continuous wave transmitted by the fourth modulation unit 205-4 through the fourth continuous wave filter 204-4. The time to modulate the wave is the same time.

The third modulation unit 205-3 is connected to the third continuous wave filter 204-3 and the third terminal of the fourth circulator 202-4. The fourth modulation unit 205-4 is connected to the fourth continuous wave filter 204-4 and the third terminal of the third circulator 202-3.

The demodulation unit 206a acquires and acquires a data signal that has passed through the first data signal filter 203-1, the second data signal filter 203-2, the third data signal filter 203-3, and the fourth data signal filter 203-4. Demodulate the data signal. The demodulation unit 206a is connected to the first data signal filter 203-1, the second data signal filter 203-2, the third data signal filter 203-3, and the fourth data signal filter 203-4. The demodulation unit 206a outputs the demodulated data signal to a predetermined output destination (not shown).

(Length of wiring in the second wireless device 20a)
Here, the length of the wiring between each functional unit included in the second wireless device 20a will be described. In the second wireless device 20a, the length of the wiring from the third antenna element 201-3 to the fourth circulator 202-4 is the same as the length of the wiring from the fourth antenna element 201-4 to the third circulator 202-3. Is. More specifically, the path length of the third path and the path length of the fourth path are the same. The third path is a path from the third antenna element 201-3 to the fourth circulator 202-4 via the third circulator 202-3, the third continuous wave filter 204-3, and the third modulation unit 205-3. be. The fourth path is a path from the fourth antenna element 201-4 to the third circulator 202-3 via the fourth circulator 202-4, the fourth continuous wave filter 204-4, and the fourth modulation unit 205-4. be. Further, the route lengths of the first route, the second route, the third route, and the fourth route are the same.

Further, the length of the wiring between the third circulator 202-3 and the third antenna element 201-3 and the length of the wiring between the fourth circulator 202-4 and the fourth antenna element 201-4 are the same. be. Hereinafter, the length of the wiring between the third circulator 202-3 and the third antenna element 201-3 is referred to as the third antenna wiring length. Hereinafter, the length of the wiring between the fourth circulator 202-4 and the fourth antenna element 201-4 is referred to as the fourth antenna wiring length.
Further, the first antenna wiring length, the second antenna wiring length, the third antenna wiring length, and the fourth antenna wiring length are the same.

Further, the length of the wiring from the third antenna element 201-3 to the third modulation unit 205-3 is the same as the length of the wiring from the fourth antenna element 201-4 to the fourth modulation unit 205-4.

(About the propagation path in the second radio device 20a)
The path of propagation of the data signal received by the second radio device 20a and the unmodulated continuous wave in the second radio device 20a will be described.

First, the propagation path of the data signal and the unmodulated continuous wave received by the third antenna element 201-3 will be described. The data signal and the unmodulated continuous wave received by the third antenna element 201-3 propagate to the third circulator 202-3. The data signal and unmodulated continuous wave propagated to the third circulator 202-3 propagate from the third circulator 202-3 to the third data signal filter 203-3 and the third continuous wave filter 204-3.

Of the data signal and unmodulated continuous wave propagated to the third continuous wave filter 204-3, only the unmodulated continuous wave passes through the third continuous wave filter 204-3. The unmodulated continuous wave transmitted through the third continuous wave filter 204-3 propagates from the third continuous wave filter 204-3 to the third modulation unit 205-3.

The unmodulated continuous wave propagating to the third modulation unit 205-3 is modulated by the third modulation unit 205-3 for a predetermined period (hereinafter referred to as “third modulation period”). Hereinafter, the unmodulated continuous wave modulated by the third modulation unit 205-3 is referred to as a third modulation signal. The third modulated signal is a radio wave.

The third modulation signal propagates from the third modulation unit 205-3 to the fourth circulator 202-4. The third modulation signal propagated to the fourth circulator 202-4 propagates from the fourth circulator 202-4 to the fourth antenna element 201-4 and is radiated from the fourth antenna element 201-4.

On the other hand, of the data signal propagated to the third data signal filter 203-3 and the unmodulated continuous wave, only the data signal passes through the third data signal filter 203-3. The data signal transmitted through the third data signal filter 203-3 propagates from the third data signal filter 203-3 to the demodulation unit 206a. The data signal propagated to the demodulation unit 206a is demodulated by the demodulation unit 206a.

Next, the propagation path of the data signal and the unmodulated continuous wave received by the fourth antenna element 201-4 will be described.

The data signal and unmodulated continuous wave received by the fourth antenna element 201-4 propagate to the fourth circulator 202-4. The data signal and unmodulated continuous wave propagated to the 4th circulator 202-4 propagate from the 4th circulator 202-4 to the 4th data signal filter 203-4 and the 4th continuous wave filter 204-4.

Of the data signal and unmodulated continuous wave propagated to the fourth continuous wave filter 204-4, only the unmodulated continuous wave passes through the fourth continuous wave filter 204-4. The unmodulated continuous wave transmitted through the fourth continuous wave filter 204-4 propagates from the fourth continuous wave filter 204-4 to the fourth modulation unit 205-4.

The unmodulated continuous wave propagating to the fourth modulation unit 205-4 is modulated by the fourth modulation unit 205-4 for a predetermined period (hereinafter referred to as “fourth modulation period”). Hereinafter, the unmodulated continuous wave modulated by the fourth modulation unit 205-4 is referred to as a fourth modulation signal. The fourth modulated signal is a radio wave. The first modulation period, the second modulation period, the third modulation period, and the fourth modulation period are all the same period. That is, the start time and the length of the second modulation period, the third modulation period, and the fourth modulation period are the same as the first modulation period.

The fourth modulation signal propagates from the fourth modulation unit 205-4 to the third circulator 202-3. The fourth modulation signal propagated to the third circulator 202-3 propagates from the third circulator 202-3 to the third antenna element 201-3 and is radiated from the third antenna element 201-3.

(Second radio device with N of 3 or more)
Up to this point, the second wireless device 20a has been described by taking the second wireless device 20a in the case of N = 2 as a specific example, but the same applies to the case where N is 3 or more. Hereinafter, the case where N is 3 or more will be specifically described.

Hereinafter, when distinguishing 2 × N antenna elements 201, it is referred to as nth antenna element 201-n (n is an integer of 1 or more and 2 × N or less). The second radio device 20a is hereinafter referred to as an nth circulator 202-n when distinguishing between 2 × N circulators 202. Hereinafter, when distinguishing 2 × N data signal filters 203, it is referred to as the nth data signal filter 203-n. Hereinafter, when distinguishing 2 × N continuous wave filters 204, it is referred to as the nth continuous wave filter 204-n. Hereinafter, when distinguishing 2 × N modulation units 205, it is referred to as the nth modulation unit 205-n.

The 2 × N antenna elements 201 are located in an array. The m-th antenna element 201-m and the (m + 1) th antenna element 201- (m + 1) are located at symmetrical positions with respect to the center of the array (m is an odd number of 1 or more (2 × N-1) or less).

The first terminal of the m-th circulator 202-m is connected to the m-th antenna element 201-m. The second terminal of the m-th circulator 202-m is connected to the m-th continuous wave filter 204-m and the m-th data signal filter 203-m. The third terminal of the m-th circulator 202-m is connected to the (m + 1) th modulator 205- (m + 1).

The first terminal of the first (m + 1) circulator 202- (m + 1) is connected to the first (m + 1) antenna element 201- (m + 1). The second terminal of the first (m + 1) circulator 202- (m + 1) is connected to the second (m + 1) continuous wave filter 204- (m + 1) and the third (m + 1) data signal filter 203- (m + 1). The third terminal of the first (m + 1) circulator 202- (m + 1) is connected to the m-modulation unit 205-m.

The m-th data signal filter 203-m is connected to the m-th circulator 202-m and the demodulation unit 206a. The third (m + 1) data signal filter 203- (m + 1) is connected to the first (m + 1) circulator 202- (m + 1) and the demodulation unit 206a.

The mth continuous wave filter 204-m is connected to the mth circulator 202-m and the mth modulation unit 205-m. The (m + 1) th continuous wave filter 204- (m + 1) is connected to the th (m + 1) circulator 202- (m + 1) and the th (m + 1) modulation unit 205- (m + 1).

The m-th modulation unit 205-m is connected to the m-th continuous wave filter 204-m and the third terminal of the (m + 1) circulator 202- (m + 1). The third (m + 1) modulation unit 205- (m + 1) is connected to the third (m + 1) continuous wave filter 204- (m + 1) and the third terminal of the mth circulator 202-m.
The time at which the nth modulation unit 205-n modulates the unmodulated continuous wave transmitted through the nth continuous wave filter 204-n is the same time regardless of n. That is, all the nth modulation periods are the same, with the period in which the nth modulation unit 205-n modulates the unmodulated continuous wave as the nth modulation period. The fact that all the nth modulation periods are the same means that the start time and the length of the period of the nth modulation period are the same regardless of n.

The demodulation unit 206a acquires a data signal that has passed through the first data signal filter 203-1 to the (2 × N) data signal filter 203- (2 × N), and demodulates the acquired data signal. The demodulation unit 206a is connected to the first data signal filter 203-1 to the (2 × N) data signal filter 203- (2 × N). The demodulation unit 206a outputs the demodulated data signal to a predetermined output destination (not shown). That is, the demodulation unit 206a demodulates the data signals received by the four or more even-numbered antenna elements 221 and outputs them to a predetermined output destination (not shown).

(Wiring length)
Here, the length of the wiring between each functional unit included in the second wireless device 20a will be described.
In the second wireless device 20a, the length of the wiring from the mth antenna element 201-m to the (m + 1) th (m + 1) circulator 202- (m + 1) and the length of the wiring from the first (m + 1) antenna element 201- (m + 1) to the mth circulator 202-m. The length of the wiring up to is the same. More specifically, all of the m-th path and the (m + 1) th path are the same. The mth path is from the mth antenna element 201-m to the mth circulator 202-m, the mth continuous wave filter 204-m, and the mth modulator 205-m via the (m + 1) th circulator 202- (m + 1). It is a route leading to. The first (m + 1) path is from the first (m + 1) antenna element 201- (m + 1) to the first (m + 1) circulator 202- (m + 1), the third (m + 1) continuous wave filter 204- (m + 1), and the first (m + 1) modulation unit 205. -It is a route to the mth circulator 202-m via (m + 1).

Moreover, all the nth antenna wiring lengths are the same. The n-th antenna wiring length is the length of the wiring between the n-th circulator 202-n and the n-th antenna element 201-n.

Further, the lengths of the wirings from the nth antenna element 201-n to the nth modulation unit 205-n are all the same.

(About the output wave of the second wireless device 20a)
Hereinafter, the time from the reception of the unmodulated continuous wave by the m-th antenna element 201-m to the emission of the unmodulated continuous wave by the (m + 1) th antenna element 201- (m + 1) is referred to as the m-elapsed time. Hereinafter, the time from the reception of the unmodulated continuous wave by the (m + 1) th antenna element 201- (m + 1) to the emission of the unmodulated continuous wave by the mth antenna element 201-m is referred to as the (m + 1) elapsed time.

The path length of the nth path is the same regardless of n, the nth antenna wiring length is the same regardless of n, and the nth modulation unit 205-n is unmodulated through the nth continuous wave filter 204-n. The time for modulating the continuous wave is the same regardless of n. Therefore, all nth elapsed times are the same.

Therefore, the second radio device 20a configured in this way is a van-atter array because all the n-th elapsed times are the same.

The radio wave radiated from the nth antenna element 201-n is an output wave output by the second radio device 20a.

FIG. 10 is a flowchart showing an example of the processing flow in the wireless communication system 1 of the embodiment. Hereinafter, for the sake of simplicity of description, it is assumed that the second wireless device 20 included in the wireless communication system 1 is the second wireless device 20a, but the second wireless device 20 included in the wireless communication system 1 is the second wireless device 20. However, the processing flow is the same. When the second wireless device 20 included in the wireless communication system 1 is the second wireless device 20, it corresponds to the case of N = 1.

The first radio device 10 transmits a data signal and an unmodulated continuous wave (step S101). The second radio device 20a receives the data signal and the unmodulated continuous wave (step S102). Specifically, the data signal and the unmodulated continuous wave reach the nth antenna element 201-n and are received by the nth antenna element 201-n.

The second radio device 20a separates the data signal received in step S102 from the unmodulated continuous wave (step S103). Specifically, the data signal received by the nth antenna element 201-n passes through the nth data signal filter 203-n, and the unmodulated continuous wave received by the nth antenna element 201-n is the nth continuous wave filter. By passing through 204-n, the data signal and the unmodulated continuous wave are separated.

The second radio device 20a demodulates the data signal (step S104). Specifically, the demodulation unit 206a demodulates the data signal that has passed through the nth data signal filter 203-n.
The second radio device 20a modulates the unmodulated continuous wave (step S105). Specifically, the nth modulation unit 205-n modulates the unmodulated continuous wave received by the nth antenna element 201-n and transmitted through the nth continuous wave filter 204-n.

The second radio device 20a radiates an unmodulated continuous wave after being modulated by the nth modulation unit 205-n (step S106). Specifically, the unmodulated continuous wave after being modulated by the m-modulation unit 205-m is radiated from the (m + 1) th antenna element 201- (m + 1). The unmodulated continuous wave after being modulated by the first (m + 1) modulation unit 205- (m + 1) is radiated from the mth antenna element 201-m.

The first radio device 10 receives the radio wave radiated from the second radio device 20a (step S107). Specifically, the first radio device 10 receives the radio wave radiated by the second radio device 20a in step S106.

The second radio device 20a configured as described above includes the nth data signal filter 203-n, the nth continuous wave filter 204-n, the nth modulation unit 205-n, and the demodulation unit 206a, and is the nth. The path length of the path is the same regardless of n, the nth antenna wiring length is the same regardless of n, and the nth modulation unit 205-n is an unmodulated continuous wave transmitted through the nth continuous wave filter 204-n. Since the time to modulate the wave is the same regardless of n, it is possible to receive the data signal and transmit the output wave even though it is a van atta array.

The wireless communication system 1 configured in this way includes a first wireless device 10 and a second wireless device 20a. Therefore, bidirectional communication using the wireless communication system 1 van atta array configured in this way is possible. Specifically, the second radio device 20 configured in this way is capable of frequency division duplex (FDD) using a van-atter array.

In the second radio device 20a configured in this way, one demodulation unit 206a demodulates the data signal received by the four or more even-numbered antenna elements 201. Therefore, the second wireless device 20a configured in this way can suppress the increase in size of the device.

(Modification example)
The demodulation units 206 and 206a may demodulate the data signal by the diversity reception method. Hereinafter, the demodulation unit 206 will be specifically described for the sake of simplicity. When the power of the first data signal and the power of the second data signal are different, the demodulation unit 206 may demodulate only the data signal having high power. The first data signal is a data signal received by the first antenna element 211-1. The second data signal is a data signal received by the second antenna element 201-2. The demodulation unit 206 may demodulate only the high power data signal by any method as long as it can demodulate only the high power data signal. For example, the demodulation unit 206 may demodulate only high-power data signals by the selective synthesis method.

The situation where the power of the first data signal and the power of the second data signal are different occurs, for example, when the direction in which the data signal arrives at the second radio device 20 is not the front. The data signal is the front surface of the second radio device 20 when the data signal is radiated from a light source located on the perpendicular bisector of the straight line connecting the first antenna element 211-1 and the second antenna element 201-2. Comes from.
When the direction in which the data signal arrives at the second radio device 20 is not the front, the time when the data signal reaches the first antenna element 201-1 and the time when the data signal reaches the second antenna element 201-2. Is different.

The first radio device 10 may transmit a pilot signal. When the first radio device 10 transmits a pilot signal, the demodulators 206 and 206a may perform channel estimation using the pilot signal. Further, in such a case, the demodulation units 206 and 206a may calculate the weight and execute the maximum ratio synthesis by executing the eigenvalue decomposition of the correlation matrix of the received radio waves.

The second wireless device 20a does not necessarily have to include only one demodulation unit 206a, and may include a plurality of demodulation units 206a. For example, the second radio device 20a may include one demodulation unit 206a for each pair of antenna elements 201 of the mth antenna element 201-m and the second (m + 1) antenna element 201- (m + 1). ..

The 2 × N antenna elements 201 may be positioned in any position as long as they are positioned in an array shape. The 2 × N antenna elements 201 may be located, for example, in a linear array or in a planar array. The array shape means that 2 × N antenna elements 201 are regularly arranged.

The distance between the m-th antenna element 201-m and the (m + 1) th antenna element 201- (m + 1) (hereinafter referred to as "m-th antenna distance") may be less than the wavelength λ. In such a case, as in the case where the distance d between the first antennas is less than the wavelength λ, the output in the direction of propagating to the first radio device 10 is higher than when the distance between the mth antennas is greater than or equal to the wavelength λ. The wave intensity is strong.
Further, as in the case where the distance d between the first antennas is less than the wavelength λ, when the distance between the mth antennas is less than the wavelength λ / 2, the generation of great tein gloves is suppressed.

The second wireless device 20 and the second wireless device 20a are examples of wireless devices. Note that step S101 is an example of a transmission step. Note that step S102 is an example of the first reception step. Note that step S103 is an example of a separation step. Note that step S104 is an example of a demodulation step. Note that step S105 is an example of a modulation step. Note that step S106 is an example of a radiation step. Note that step S107 is an example of the second reception step.

All or part of the functions of the first wireless device 10 and the second wireless devices 20 and 20a are ASIC (Application Specific Integrated Circuit), PLD (Programmable Logic Device), FPGA (Field Programmable Gate Array), etc. It may be realized by using the hardware of. The program may be recorded on a computer-readable recording medium. The computer-readable recording medium is, for example, a flexible disk, a magneto-optical disk, a portable medium such as a ROM or a CD-ROM, or a storage device such as a hard disk built in a computer system. The program may be transmitted over a telecommunication line.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and includes designs and the like within a range that does not deviate from the gist of the present invention.

1 ... wireless communication system, 10 ... first wireless device, 101 ... data transmitter, 102 ... modulated wave transmitter, 103 ... receiver, 20, 20a ... second wireless device, 201 ... antenna element, 202 ... circulator, 203. … Data signal filter, 204… Continuous wave filter, 205… Modulation section, 206, 206a… Demodulation section

Claims (8)

A data transmission unit that transmits a data signal that is a modulated radio wave, a modulated wave transmission unit that transmits an unmodulated continuous wave that is an unmodulated radio wave that has a frequency different from that of the data signal, and a radio wave reception unit. A first radio device including a receiving unit, and
A second radio device that receives the data signal and the unmodulated continuous wave, and
Equipped with
The second wireless device is
The 2 × N antenna elements of the first (2 × N) antenna element that receive the data signal and the unmodulated continuous wave, and
A data signal filter that transmits radio waves of the frequency of the data signal,
A continuous wave filter that transmits radio waves of the unmodulated continuous wave frequency,
A demodulation unit that demodulates the data signal that has passed through the data signal filter,
A modulation unit that modulates the unmodulated continuous wave that has passed through the continuous wave filter, and
Equipped with
The 2 × N antenna elements are located in an array, and the mth antenna element (m is an odd number of 1 or more (2 × N) or less) and the (m + 1) antenna element are symmetrical with respect to the center of the array. An antenna element located at a position
The unmodulated continuous wave received by the m-th antenna element is modulated by the modulation unit after passing through the continuous wave filter, modulated by the modulation unit, and then radiated from the (m + 1) antenna element.
The unmodulated continuous wave received by the (m + 1) antenna element is modulated by the modulation unit after passing through the continuous wave filter, modulated by the modulation unit, and then radiated from the m antenna element.
The time from when the m-th antenna element receives the unmodulated continuous wave to when the unmodulated continuous wave is radiated after the first (m + 1) antenna element is modulated is defined as the m-elapsed time. m + 1) All nth n. The elapsed time is the same,
The first radio device receives the unmodulated continuous wave after being modulated by the second radio device, and receives the unmodulated continuous wave.
The timing at which the data transmission unit transmits the data signal and the timing at which the modulated wave transmission unit transmits the unmodulated continuous wave are simultaneous.
The timing at which the m-th antenna element receives the data signal and the timing at which the unmodulated continuous wave is received are simultaneous.
Wireless communication system. The second radio device, as the data signal filter, is an nth data signal filter that transmits radio waves of the frequency of the data signal received by the nth antenna element (n is an integer of 1 or more (2 × N) or less). Equipped with
The second radio device includes, as the continuous wave filter, an nth continuous wave filter that transmits a radio wave having a frequency of the unmodulated continuous wave received by the nth antenna element.
The second radio device includes, as the modulation unit, an nth modulation unit that modulates the unmodulated continuous wave that has passed through the nth continuous wave filter.
The wireless communication system according to claim 1, wherein the demodulation unit demodulates the data signal that has passed through the nth data signal filter. The distance between the m-th antenna element and the (m + 1) antenna element is less than the wavelength of the unmodulated continuous wave in the space in which the unmodulated continuous wave propagates.
The wireless communication system according to claim 1 or 2. The period in which the nth modulation unit modulates the unmodulated continuous wave is defined as the nth modulation period, and all the nth modulation periods are the same.
The wireless communication system according to claim 2. A wireless communication method performed by the wireless communication system according to claim 1.
The first radio device included in the wireless communication system transmits a data signal which is a modulated radio wave and an unmodulated continuous wave which is a radio wave having a frequency different from the data signal and is an unmodulated continuous wave. Send step and
A first reception step in which the second wireless device included in the wireless communication system receives the data signal and the unmodulated continuous wave,
A separation step in which the second radio device separates the data signal from the unmodulated continuous wave,
A demodulation step in which the second radio device demodulates the data signal,
A modulation step in which the second radio device modulates the unmodulated continuous wave,
A radiation step in which the second radio device radiates the unmodulated continuous wave after being modulated in the modulation step.
A second reception step in which the first radio device receives the unmodulated continuous wave radiated in the radiation step, and a second reception step.
Wireless communication method with. A modulated wave that transmits the data signal transmitted by the data transmission unit that transmits the data signal, which is a modulated radio wave, and an unmodulated continuous wave, which is a radio wave having a frequency different from that of the data signal and is not modulated. The 2 × N antenna elements of the first (2 × N) antenna element that receive the unmodulated continuous wave transmitted by the transmitter , and
An nth data signal filter that transmits the data signal received by the nth antenna element (n is an integer of 1 or more (2 × N) or less) and
The nth continuous wave filter that transmits the radio wave of the frequency of the unmodulated continuous wave received by the nth antenna element, and the nth continuous wave filter.
The nth modulation unit that modulates the unmodulated continuous wave that has passed through the nth continuous wave filter, and the nth modulation unit.
A demodulation unit that demodulates the data signal that has passed through the nth data signal filter, and
Equipped with
The 2 × N antenna elements are located in an array, and the mth antenna element (m is an odd number of 1 or more (2 × N) or less) and the (m + 1) antenna element are symmetrical with respect to the center of the array. An antenna element located at a position
The unmodulated continuous wave received by the m-th antenna element is modulated by the m-modulation unit after passing through the m-th continuous wave filter, and after being modulated by the m-modulation unit, the (m + 1) antenna. Emitted from the element
The unmodulated continuous wave received by the (m + 1) antenna element is modulated by the (m + 1) modulation unit after passing through the (m + 1) continuous wave filter, and is modulated by the (m + 1) modulation unit. After that, it is radiated from the m-th antenna element.
The time from when the m-th antenna element receives the unmodulated continuous wave to when the unmodulated continuous wave is radiated after the first (m + 1) antenna element is modulated is defined as the m-elapsed time. m + 1) All nth n. The elapsed time is the same ,
The timing at which the data transmission unit transmits the data signal and the timing at which the modulated wave transmission unit transmits the unmodulated continuous wave are simultaneous.
The timing at which the m-th antenna element receives the data signal and the timing at which the unmodulated continuous wave is received are simultaneous.
Wireless communication device. A data transmission unit that transmits a data signal that is a modulated radio wave, a modulated wave transmission unit that transmits an unmodulated continuous wave that is an unmodulated radio wave that has a frequency different from that of the data signal, and a radio wave reception unit. A first radio device including a receiving unit, and
A second radio device that is a van-atter array that receives the data signal and the unmodulated continuous wave, and
Equipped with
The second wireless device is
A data signal filter that transmits radio waves of the frequency of the data signal,
A continuous wave filter that transmits radio waves of the unmodulated continuous wave frequency,
A demodulation unit that demodulates the data signal that has passed through the data signal filter,
A modulation unit that modulates the unmodulated continuous wave that has passed through the continuous wave filter, and
Equipped with
The second radio device radiates the unmodulated continuous wave after being modulated by the modulation unit.
The first radio device receives the unmodulated continuous wave after being modulated by the second radio device, and receives the unmodulated continuous wave.
The timing at which the data transmission unit transmits the data signal and the timing at which the modulated wave transmission unit transmits the unmodulated continuous wave are simultaneous.
The timing at which the m-th antenna element receives the data signal and the timing at which the unmodulated continuous wave is received are simultaneous.
Wireless communication system. The second radio device is located in an array, and the m-th antenna element (m is an odd number of 1 or more (2 × N) or less) and the (m + 1) antenna element are located symmetrically with respect to the center of the array. Equipped with a positioned antenna element,
The second radio device, as the data signal filter, is an nth data signal filter that transmits radio waves of the frequency of the data signal received by the nth antenna element (n is an integer of 1 or more (2 × N) or less). Equipped with
The second radio device includes, as the continuous wave filter, an nth continuous wave filter that transmits a radio wave having a frequency of the unmodulated continuous wave received by the nth antenna element.
The second radio device includes, as the modulation unit, an nth modulation unit that modulates the unmodulated continuous wave that has passed through the nth continuous wave filter.
The demodulation unit demodulates the data signal that has passed through the nth data signal filter.
The unmodulated continuous wave received by the m-th antenna element is modulated by the m-modulation unit after passing through the m-th continuous wave filter, and after being modulated by the m-modulation unit, the (m + 1) antenna. Emitted from the element
The unmodulated continuous wave received by the (m + 1) antenna element is modulated by the (m + 1) modulation unit after passing through the (m + 1) continuous wave filter, and is modulated by the (m + 1) modulation unit. After that, it is radiated from the m-th antenna element.
The time from when the m-th antenna element receives the unmodulated continuous wave to when the unmodulated continuous wave is radiated after the first (m + 1) antenna element is modulated is defined as the m-elapsed time. m + 1) All nth n. Elapsed time is the same,
The wireless communication system according to claim 7.

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