Transmission device and transmission method

Abstract

This transmission device comprises: a generation unit that generates an Airy beam by performing phase modulation and Fourier transformation on a signal to be transmitted to at least one reception device; and a control unit that controls an angle at which a side lobe of the Airy beam is emitted by performing coordinate transformation based on linear transformation on a phase distribution of the phase-modulated signal.

Description

Transmitting device and transmission method

[0001] The present invention relates to a transmitting device and a transmitting method.

[0002] Conventionally, there is a known technique in which a transmitting device transmits signals using an Airy beam (see Non-Patent Document 1). An Airy beam is a beam that can be generated by applying a third-order phase change to a two-dimensional plane.

[0003] Figure 9A shows the intensity distribution of the cross-section of the Airy beam in the x-y plane. In Figure 9A, the horizontal axis represents the x-axis and the vertical axis represents the y-axis. In Figure 9A, the main lobe of the Airy beam is generated near the center of the figure. In Figure 9A, side lobes are generated upwards and to the left from the main lobe.

[0004] Figure 9B shows the intensity distribution of the cross-section of the Airy beam in the z-x plane. In Figure 9B, the horizontal axis represents the z axis, and the vertical axis represents the x axis. In Figure 9B, the z axis direction is the propagation direction of the signal transmitted by the transmitter. In Figure 9B, a main lobe is generated such that as the value of the z axis increases, the value near the center of the x axis approaches 0 in a curved manner. In Figure 9B, side lobes are generated in the region above the main lobe.

[0005] Z. Pang, et al. , “Partially coherent quasi-airy beams with controllable acceleration”, Physical Review, A. 102.063519 (2020).

[0006] The Airy beam used in Non-Patent Document 1 has, in addition to the strongest beam (main lobe), a 90-degree spread (side lobes) in the x-y plane, as shown in Figure 9A, which imposes constraints on beam formation.

[0007] For example, if one transmitting device sends a signal to a receiving device using Airy beam, and another transmitting device also sends a signal to that receiving device using Airy beam, the side lobe region of the Airy beam generated by one transmitting device and the side lobe region of the Airy beam generated by the other transmitting device may overlap, potentially degrading the communication quality.

[0008] The present invention aims to provide a technology that can prevent a decrease in communication quality by controlling the side lobe region of the Airy beam generated by the transmitting device.

[0009] One aspect of the present invention is a transmitting device comprising: a generation unit that generates a first Airy beam by performing phase modulation and Fourier transform on a signal to be transmitted to at least one receiving device; and a control unit that controls a first angle for illuminating the first side lobe of the first Airy beam by performing a coordinate transformation based on a linear transformation on the phase distribution of the phase-modulated signal.

[0010] Another aspect of the present invention is a transmission method comprising: a generation process for generating an Airy beam by performing phase modulation and Fourier transform on a signal to be transmitted to at least one receiving device; and a control process for controlling the angle at which the side lobes of the Airy beam are irradiated by performing a coordinate transformation based on a linear transformation on the phase distribution of the phase-modulated signal.

[0011] This invention makes it possible to prevent a decrease in communication quality by controlling the side lobe region of the Airy beam generated by the transmitting device.

[0012] This is a schematic diagram of a communication system according to the first embodiment of the present invention. This is a diagram showing an example of an Airy beam irradiated by a transmitting device according to the first embodiment of the present invention. This is a diagram showing another example of an Airy beam irradiated by a transmitting device according to the first embodiment of the present invention. This is a diagram showing yet another example of an Airy beam irradiated by a transmitting device according to the first embodiment of the present invention. This is a flowchart showing an overview of the processing of a transmitting device according to the first embodiment of the present invention. This is a schematic diagram of a communication system according to the second embodiment of the present invention. This is a flowchart showing an overview of the processing of a transmitting device according to the second embodiment of the present invention. This is a schematic diagram of a communication system according to the third embodiment of the present invention. This is a flowchart showing an overview of the processing of a transmitting device according to the third embodiment of the present invention. This is a diagram showing the intensity distribution of the cross-section of the Airy beam in the x-y plane. This is a diagram showing the intensity distribution of the cross-section of the Airy beam in the z-x plane.

[0013] Hereinafter, several aspects of the present invention will be described with reference to the drawings.

[0014] [First Embodiment] First, a first embodiment of the present invention will be described. Figure 1 is a schematic diagram of a communication system 100a according to the first embodiment of the present invention. The communication system 100a includes a transmitting device 10a and receiving devices 20a-1, 20a-2, and 20a-3.

[0015] The transmitting device 10a comprises a signal generation unit 11a, a wireless transmission unit 12a, an antenna 13a, a phase modulation lens 14a, and a Fourier transform lens 15a. The transmitting device 10a also has a control unit which controls each part of the transmitting device 10a and is composed of a CPU (Central Processing Unit), but this is omitted from the illustration in Figure 1. The transmitting device 10a also has a storage unit which stores data to be transmitted from the transmitting device 10a to the receiving devices 20a-1, 20a-2, and 20a-3, as well as data for driving the transmitting device 10a, but this is also omitted from the illustration in Figure 1.

[0016] The signal generator 11a generates a signal to be transmitted from the transmitting apparatus 10a to the receiving apparatuses 20a-1, 20a-2, and 20a-3, and outputs the generated signal to the wireless transmitter 12a. The wireless transmitter 12a performs processes including carrier wave generation, modulation, frequency conversion, filtering, amplification, and impedance matching on the signal output from the signal generator 11a, and outputs the processed signal to the antenna 13a.

[0017] The antenna 13a converts the signal output by the wireless transmitter 12a into an electromagnetic wave, and radiates the electromagnetic wave into the air as a wireless signal. The phase modulation lens 14a performs third-order phase modulation φ on the electromagnetic wave radiated from the antenna 13a １ is performed. Here, the phase modulation φ １ can be expressed by the following formula (1).

[0018]

[0019] In the formula (1), b0 is a phase constant, k = λ / 2π, and f １ is the focal length of the lens. Furthermore, in the formula (1), x' is represented by the following formula (2), and y' is represented by the following formula (3).

[0020]

[0021]

[0022] In the first embodiment of the present invention, an initial phase change is imparted to the electromagnetic wave radiated from the antenna 13a. With respect to the general cubic initial phase change α(x ３ +y ３ ) provided for generating an Airy beam (where α is a scaling coefficient of the third-order phase term), parameters θ １ and θ ２ (0<θ １ , θ ２ <2π) are used to perform processing for the x-axis and y-axis using the linear transformation matrix A represented by the following formula (4).

[0023]

[0024] Accordingly, by controlling the spread of side lobes in the x'-axis and y'-axis directions starting from 90 degrees, the region where interference occurs can be arbitrarily controlled. This makes it possible to arbitrarily form a region that is not affected by interference, and establish communication.

[0025] In the first embodiment of the present invention, instead of a simple rotation matrix, as shown in the above formula (4), the linear transformation matrix A is θ １ and θ ２ By using the two parameters of , different coordinate rotations can be applied to the x-axis component and the y-axis component respectively, making it possible to narrow or expand the side lobes.

[0026] The Fourier transform lens 15a performs a Fourier transform φ for generating an Airy beam distribution at the focal point on the electromagnetic wave emitted from the phase modulation lens 14a ２ processing. The Fourier transform φ ２ can be expressed by the following formula (5).

[0027]

[0028] The phase modulation lens 14a and the Fourier transform lens 15a are implemented by dielectric lenses or metasurfaces. Note that the phase modulation lens 14a and the Fourier transform lens 15a may also be implemented using a metasurface employing an active element that can adaptively change the phase.

[0029] The phase modulation lens 14a and the Fourier transform lens 15a function as a phase modulation unit. The phase modulation lens 14a and the Fourier transform lens 15a may be implemented by one or a plurality of lenses in which the functions of these lenses are integrated or separated.

[0030] The receiving devices 20a-1, 20a-2, and 20a-3 are located in the z-axis direction (Figure 1), which is the direction of propagation of the electromagnetic waves irradiated by the Fourier transform lens 15a of the transmitting device 10a. In the first embodiment of the present invention, the Airy beam transmitted by the transmitting device 10a is controlled according to the region in which the receiving devices 20a-1, 20a-2, and 20a-3 are located. For example, the Airy beam transmitted by the transmitting device 10a is controlled so that it can be received by the receiving device 20a-1, but not by the receiving device 20a-2.

[0031] Figures 2A, 2B, and 2C show an example of an Airy beam irradiated by a transmitting device 10a according to the first embodiment of the present invention. In Figures 2A, 2B, and 2C, the horizontal axis represents the x-axis and the vertical axis represents the y-axis.

[0032] Figure 2A shows the case where the angle of the side lobe of the Airy beam transmitted by the transmitter 10a is not controlled. In other words, in Figure 2A, θ １ = θ ２ This shows the case where the value is 0. In Figure 2A, a main lobe is generated as a point near the center of Figure 2, a first side lobe is generated downward from that main lobe, and a second side lobe is generated to the right from that main lobe.

[0033] Figure 2B shows an example where the angle of the side lobe of the Airy beam transmitted by the transmitter 10a is controlled. Specifically, in Figure 2B, θ １ = π and θ ２ This shows the case where = π. The first side lobe shown in Figure 2A is, in Figure 2B, with the main lobe as the axis, θ １ It is rotating counterclockwise on the x-y plane by π / 6. Also, the second side lobe shown in Figure 2A is, in Figure 2B, around the main lobe as an axis, θ ２ = It is rotating counterclockwise by π on the x-y plane. In Figure 2A, the angle between the first and second side lobes was 90 degrees, but in Figure 2B, the angle between the first and second side lobes is less than 90 degrees.

[0034] Figure 2C shows another example where the angle of the side lobes of the Airy beam transmitted by the transmitter 10a is controlled. Specifically, in Figure 2C, θ １ = π / 6, and θ ２ This shows the case where = 4π / 3. The first side lobe shown in Figure 2A is, in Figure 2C, with the main lobe as the axis, θ １ It is rotating counterclockwise on the x-y plane by π / 6. Also, the second side lobe shown in Figure 2A is, in Figure 2C, around the main lobe as an axis, θ ２ = It is rotating counterclockwise on the x-y plane by 4π / 3. In Figure 2A, the angle between the first and second side lobes was 90 degrees, but in Figure 2C, the angle between the first and second side lobes is greater than 90 degrees.

[0035] Figure 3 is a flowchart illustrating the processing of the transmitting device 10a according to the first embodiment of the present invention. First, the signal generation unit 11a generates a signal to be transmitted from the transmitting device 10a to the receiving devices 20a-1, 20a-2, and 20a-3 (step S101). Next, the wireless transmission unit 12a transmits the signal generated in step S101 as a wireless signal via the antenna 13a (step S102).

[0036] Next, the phase modulation lens 14a modulates the radio signal transmitted in step S102 with respect to its phase (i.e., the phase modulation φ described above). １ ) is performed (step S103). This phase modulation φ １ This is based on how much you want to change the irradiation angles of the first and second side lobes included in the Airy beam, θ １ and θ ２ This is done by setting the following. Next, the Fourier transform lens 15a performs a Fourier transform on the radio signal that has been phase-modulated in step S103 (that is, the Fourier transform φ described above). ２ ) is performed (step S104).

[0037] By performing the process shown in the flowchart in Figure 3, the main lobe and θ １ and θ ２An Airy beam is generated having multiple side lobes with varying angles, and this beam is transmitted from the transmitting device 10a to the receiving devices 20a-1, 20a-2, and 20a-3. In the first embodiment of the present invention, as shown in Figure 2B, by reducing the angle between the first side lobe and the second side lobe, the side lobe region generated by the transmitting device 10a can be controlled to avoid interference with the side lobe regions generated by other transmitting devices, thereby preventing deterioration of communication quality.

[0038] Furthermore, according to the first embodiment of the present invention, the side lobe region generated by the transmitting device 10a can avoid interference with the side lobe region generated by other transmitting devices. Therefore, processing and circuits for restoring the signal when interference occurs and communication quality deteriorates are unnecessary, thus reducing signal processing costs and circuit size. In addition, in the first embodiment of the present invention, as shown in Figure 2C, by increasing the angle between the first side lobe and the second side lobe, it is possible to control communication with multiple receiving devices located over a wide area.

[0039] [Second Embodiment] Next, a second embodiment of the present invention will be described. The fact that the second embodiment is the same as the first embodiment of the present invention will not be explained further.

[0040] Figure 4 is a schematic diagram of a communication system 100b according to a second embodiment of the present invention. The communication system 100b includes a transmitting device 10b and receiving devices 20b-1 and 20b-2. The transmitting device 10b includes a signal generation unit 11b, a wireless transmitting unit 12b, an antenna 13b, a phase modulation lens 14b, a Fourier transform lens 15b, and a phase control unit 16b. The signal generation unit 11b, wireless transmitting unit 12b, antenna 13b, phase modulation lens 14b, and Fourier transform lens 15b in the second embodiment are the same as the signal generation unit 11a, wireless transmitting unit 12a, antenna 13a, phase modulation lens 14a, and Fourier transform lens 15a in the first embodiment, so their descriptions are omitted.

[0041] The phase control unit 16b controls the phase modulation lens 14b based on the feedback information transmitted by the feedback unit 24b-1 of the receiving device 20b-1 and the feedback information transmitted by the feedback unit 24b-2 of the receiving device 20b-2.

[0042] In the second embodiment, information on received power is used as feedback information from receiving devices 20b-1 and 20b-2. Specifically, the transmitting device 10b transmits control signals to receiving devices 20b-1 and 20b-2, and receives feedback from the desired receiving device (e.g., receiving device 20b-1) that wants to establish transmission, and from the other receiving device (e.g., receiving device 20b-2) that does not transmit, regarding information on the received power of the transmitted control signals. At this time, the phase control unit 16b controls the θ such that the received power of receiving device 20b-1 that transmits is above a certain specified threshold, and the received power of receiving device 20b-2 that does not transmit is below a specified threshold. １ and θ ２ Increase or decrease it.

[0043] The receiving device 20b-1 comprises an antenna 21b-1, a wireless receiving unit 22b-1, a signal processing unit 23b-1, and a feedback unit 24b-1. The antenna 21b-1 receives the Airy beam emitted from the Fourier transform lens 15b of the transmitting device 10b, converts it from electromagnetic waves into an electrical signal, and outputs it to the wireless receiving unit 22b-1. The wireless receiving unit 22b-1 processes the electrical signal output from the antenna 21b-1, such as amplification, shaping, and down-conversion, and outputs it to the signal processing unit 23b-1. The signal processing unit 23b-1 performs processing such as demodulation and decoding.

[0044] When a control signal is transmitted from the transmitting device 10b and received by the antenna 21b-1, the feedback unit 24b-1 transmits information indicating the received power at that time (such as the received power value) and information indicating whether or not the receiving device 20b-1 wishes to receive a signal from the transmitting device 10b.

[0045] The receiving device 20b-2 includes an antenna 21b-2, a wireless receiving unit 22b-2, a signal processing unit 23b-2, and a feedback unit 24b-2. The antenna 21b-2, wireless receiving unit 22b-2, signal processing unit 23b-2, and feedback unit 24b-2 of the receiving device 20b-2 perform the same processing as the antenna 21b-1, wireless receiving unit 22b-1, signal processing unit 23b-1, and feedback unit 24b-1 of the receiving device 20b-1, so their explanations are omitted.

[0046] Figure 5 is a flowchart illustrating the processing of the transmitting device 10b according to a second embodiment of the present invention. First, the wireless transmitting unit 12b transmits a control signal to the receiving devices 20b-1 and 20b-2 via the antenna 13b, phase modulation lens 14b, and Fourier transform lens 15b (step S201). Next, the phase control unit 16b receives information on the received power of the control signal transmitted in step S201 from the receiving devices 20b-1 and 20b-2 (step S202).

[0047] Next, the phase control unit 16b adjusts the Airy beam side lobes so that the received power of the receiving device that establishes transmission (here, receiving device 20b-1) is above a predetermined threshold (for example, -120 dBm), and the received power of the receiving device that does not establish transmission (here, receiving device 20b-2) is below a predetermined threshold (step S203). Next, the wireless transmission unit 12b retransmits the control signal to the receiving devices 20b-1 and 20b-2 via the antenna 13b, phase modulation lens 14b, and Fourier transform lens 15b (step S204).

[0048] Next, the phase control unit 16b receives information on the received power of the control signal retransmitted in step S204 from the receiving devices 20b-1 and 20b-2 (step S205). Next, the phase control unit 16b determines whether the received power of the receiving device that establishes transmission (here, receiving device 20b-1) is above a predetermined threshold (for example, -120 dBm) and whether the received power of the receiving device that does not establish transmission (here, receiving device 20b-2) is below a predetermined threshold (step S206).

[0049] If the received power of the receiving device that establishes transmission is not above a predetermined threshold, and the received power of the receiving device that does not establish transmission is not below a predetermined threshold, the result in step S206 is NO, and the process in step S203 is repeated. On the other hand, if the received power of the receiving device that establishes transmission is above a predetermined threshold, and the received power of the receiving device that does not establish transmission is below a predetermined threshold, the result in step S206 is YES, and the process shown in the flowchart in Figure 5 is terminated.

[0050] In the second embodiment, for receiving device 20b-1, which wishes to communicate with transmitting device 10b, the angle of the side lobes of the Airy beam emitted from transmitting device 10b is controlled so that they reach it. On the other hand, for receiving device 20b-2, which does not wish to communicate with transmitting device 10b, the angle of the side lobes of the Airy beam emitted from transmitting device 10b is controlled so that they do not reach it. As a result, the signal transmitted from transmitting device 10b can be delivered only to receiving devices that wish to communicate with transmitting device 10b, thus preventing unnecessary signal processing by receiving devices that do not wish to communicate with transmitting device 10b.

[0051] [Modified Version of the Second Embodiment] Next, a modified version of the second embodiment of the present invention will be described. The fact that the modified version of the second embodiment is the same as that of the second embodiment will not be explained further.

[0052] In a modified version of the second embodiment of the present invention, the feedback unit 24b-1 of the receiving device 20b-1 (and receiving device 20b-2) transmits to the transmitting device 10b the location information of the receiving device 20b-1 (and receiving device 20b-2) and information indicating whether the receiving device 20b-1 (and receiving device 20b-2) wishes to receive a signal from the transmitting device 10b. The feedback units 24b-1 and 24b-2 of the receiving devices 20b-1 and 20b-2 acquire the location information of the receiving device using GPS (Global Positioning System) or the like.

[0053] In the second embodiment, the transmitting device 10b performed the processing shown in the flowchart in Figure 5, but in the modified version of the second embodiment, the transmitting device 10b differs in that it performs the processing shown in the flowchart in Figure 6.

[0054] Figure 6 is a flowchart illustrating the processing of the transmitting device 10b according to a modification of the second embodiment of the present invention. First, the phase control unit 16b receives position information of the receiving devices 20b-1 and 20b-2 from the receiving devices 20b-1 and 20b-2 (step S301). Next, the phase control unit 16b adjusts the Airy beam side lobes so that receiving devices that establish transmission (e.g., receiving device 20b-1) are in the transmission area of ​​the side lobes, and receiving devices that do not establish transmission (e.g., receiving device 20b-2) are not in the transmission area of ​​the side lobes (step S302).

[0055] After a predetermined time (for example, 0.1 seconds) has elapsed, the phase control unit 16b receives the position information of the receiving devices 20b-1 and 20b-2 again from the receiving devices 20b-1 and 20b-2 (step S303). Next, the phase control unit 16b determines whether a receiving device that establishes transmission (for example, receiving device 20b-1) has entered the transmission area of ​​the sidelobe, and whether a receiving device that does not establish transmission (for example, receiving device 20b-2) has left the transmission area of ​​the sidelobe (step S304). This determination is made using the position information of the transmitting device 10b acquired by GPS or the like, information of the area in which the sidelobe of the Airy beam of the transmitting device 10b is formed, and the position information of the receiving devices 20b-1 and 20b-2 received in step S303.

[0056] If the transmission area of ​​the sidelobe of the transmitting device 10b does not contain a receiving device that establishes transmission (for example, receiving device 20b-1), and does not contain a receiving device that does not establish transmission (for example, receiving device 20b-2), then step S304 is determined to be NO, and the process in step S302 is repeated.

[0057] On the other hand, if a receiving device that establishes transmission (e.g., receiving device 20b-1) is located within the transmission area of ​​the side lobe of the transmitting device 10b, and no receiving devices that do not establish transmission (e.g., receiving device 20b-2) are located within the transmission area of ​​the side lobe of the transmitting device 10b, then the result is determined to be YES in step S304, and the process shown in the flowchart in Figure 6 is terminated.

[0058] In a modified version of the second embodiment of the present invention, the receiving device that wishes to establish transmission and other receiving devices that do not wish to establish transmission are fed back and acquired by the transmitting device 10b. At this time, the transmitting device 10b calculates the angles of the desired receiving device 20b-1 and the other receiving devices 20b-2 from the position information and sets θ so that the beam is not transmitted to the other receiving device 20b-2. １ and θ ２ Increase or decrease it.

[0059] In the second embodiment, for receiving device 20b-1, which wishes to communicate with transmitting device 10b, the angle of the side lobe is controlled so that it falls within the region of the side lobe of the Airy beam emitted from transmitting device 10b. On the other hand, for receiving device 20b-2, which does not wish to communicate with transmitting device 10b, the angle of the side lobe is controlled so that it does not fall within the region of the side lobe of the Airy beam emitted from transmitting device 10b. As a result, the signal transmitted from transmitting device 10b can be delivered only to receiving devices that wish to communicate with transmitting device 10b, thereby preventing unnecessary signal processing by receiving devices that do not wish to communicate with transmitting device 10b.

[0060] [Third Embodiment] Next, a third embodiment of the present invention will be described. The fact that the third embodiment of the present invention is the same as that of the first embodiment of the present invention will not be explained further.

[0061] Figure 7 is a schematic diagram of a communication system 100c according to a third embodiment of the present invention. The communication system 100c includes transmitting devices 10c-1 and 10c-2. Transmitting device 10c-1 includes a signal generation unit 11c-1, a wireless transmission unit 12c-1, an antenna 13c-1, a phase modulation lens 14c-1, a Fourier transform lens 15c-1, and a phase control unit 16c-1. Transmitting device 10c-2 includes a signal generation unit 11c-2, a wireless transmission unit 12c-2, an antenna 13c-2, a phase modulation lens 14c-2, a Fourier transform lens 15c-2, and a phase control unit 16c-2. The signal generation units 11c-1, 11c-2, wireless transmission units 12c-1, 12c-2, antennas 13c-1, 13c-2, phase modulation lenses 14c-1, 14c-2, and Fourier transform lenses 15c-1, 15c-2 in the third embodiment are the same as the signal generation unit 11a, wireless transmission unit 12a, antenna 13a, phase modulation lens 14a, and Fourier transform lens 15a in the first embodiment, so their descriptions are omitted.

[0062] The phase control unit 16c-1 controls the phase modulation lens 14c-1 based on irradiation information acquired from another transmitter 10c-2. In the third embodiment, the transmitter 10c-1 uses the position information of the transmitter 10c-2 and information indicating the area to which the transmitter 10c-2 irradiates with the Airy beam as irradiation information from the other transmitter 10c-2. In the third embodiment, the relative positions of each transmitter 10c-1 and 10c-2 are shared between the transmitters 10c-1 and 10c-2 in advance, and the main lobe, side lobes, or both of the beam transmitted from the transmitter 10c-1 are set such that the main lobe, side lobes, or both of the beam transmitted from the other transmitter 10c-2 do not interfere with each other. １ and θ ２ Increase or decrease it.

[0063] Figure 8 is a flowchart illustrating the processing of the transmitter 10c-1 according to a third embodiment of the present invention. First, the phase control unit 16c-1 of the transmitter 10c-1 receives information about the transmission area of ​​the Airy beam of the other transmitter 10c-2 from the other transmitter 10c-2 (step S401).

[0064] Next, the phase control unit 16c-1 of the transmitter 10c-1 determines whether the transmission area of ​​the Airy beam of the transmitter 10c-1 overlaps with the transmission area of ​​the Airy beam of the other transmitter 10c-2 (step S402). If the transmission area of ​​the Airy beam of the transmitter 10c-1 does not overlap with the transmission area of ​​the Airy beam of the other transmitter 10c-2, the result in step S402 is NO, and the process in step S404, described later, is performed. On the other hand, if the transmission area of ​​the Airy beam of the transmitter 10c-1 overlaps with the transmission area of ​​the Airy beam of the other transmitter 10c-2, the result in step S402 is YES, and the process in step S403 described below is performed.

[0065] In other words, the phase control unit 16c-1 of the transmitter 10c-1 adjusts the Airy beam so that the transmission area of ​​the Airy beam of the transmitter 10c-1 does not overlap with the transmission area of ​​the Airy beam of the other transmitter 10c-2 (step S403). Next, in step S402, the phase control unit 16c-1 of the transmitter 10c-1 determines that the Airy beam of the transmitter 10c-1 does not overlap with the Airy beam of the other transmitter 10c-2, or in step S403, it uses the Airy beam of the transmitter 10c-1 that has been adjusted so that it does not overlap with the Airy beam of the other transmitter 10c-2 to start transmitting a signal to the receiver (step S404).

[0066] According to a third embodiment of the present invention, the Airy beam (particularly the side lobes) irradiated by the transmitting device 10c-1 is adjusted so that it does not overlap with the Airy beam (particularly the side lobes) irradiated by the other transmitting device 10c-2, and then the Airy beam is irradiated from the transmitting device 10c-1 to the receiving device. This prevents interference between the Airy beam irradiated by the transmitting device 10c-1 and the Airy beam irradiated by the other transmitting device 10c-2, thereby improving the communication quality of the communication system 100c.

[0067] In the third embodiment of the present invention, the case in which the transmitting device 10c-1 performs the processing shown in the flowchart of Figure 8 and the transmitting device 10c-2 does not perform the processing shown in the flowchart of Figure 8 has been described, but the invention is not limited to this. For example, the transmitting device 10c-2 may perform the processing shown in the flowchart of Figure 8, and the transmitting device 10c-1 may not perform the processing shown in the flowchart of Figure 8.

[0068] Alternatively, instead of the transmitting devices 10c-1 and 10c-2 performing the processing shown in the flowchart in Figure 8, a higher-level device of the transmitting devices 10c-1 and 10c-2 may adjust the Airy beam irradiated by transmitting device 10c-1 and the Airy beam transmitted by transmitting device 10c-2 so as not to interfere with each other, and notify the transmitting devices 10c-1 and 10c-2 of the adjustment result from the higher-level device, so that the transmitting devices 10c-1 and 10c-2 start irradiating with the Airy beam based on the notification result.

[0069] Furthermore, at least some of the functions of the transmitting and receiving devices in the first, second, and third embodiments described above, and the modified version of the second embodiment, may be implemented by a computer. In that case, the functions may be implemented by recording a program for implementing these functions on a computer-readable recording medium, loading the program recorded on this recording medium into a computer system, and executing it. Here, "computer system" includes hardware such as an OS (Operating System) and peripheral devices. Furthermore, "computer-readable recording medium" refers to portable media such as flexible disks, magneto-optical disks, ROMs (Read Only Memory), CD-ROMs, and storage devices such as hard disks built into a computer system. In addition, "computer-readable recording medium" may also include those that dynamically hold programs for a short period of time, such as communication lines when transmitting programs via networks such as the Internet or communication lines such as telephone lines, and those that hold programs for a certain period of time, such as volatile memory inside a computer system that acts as a server or client in such cases. Furthermore, the above program may be for the purpose of realizing some of the functions described above, or it may be able to realize the above functions in combination with a program already recorded in the computer system, or it may be realized using a programmable logic device such as an FPGA.

[0070] Although several embodiments of the present invention have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments and includes designs and the like that do not depart from the spirit of the invention.

[0071] The present invention can be applied to transmitting devices and transmitting methods that require preventing a decrease in communication quality by controlling the side lobe region of the Airy beam generated by the transmitting device.

[0072] 10a, 10b, 10c-1, 10c-2... Transmitting device, 11a, 11b, 11c-1, 11c-2... Signal generation unit, 12a, 12b, 12c-1, 12c-2... Wireless transmitting unit, 13a, 13b, 13c-1, 13c-2... Antenna, 14a, 14b, 14c-1, 14c-2... Phase modulation lens (also called generation unit), 15a, 15b, 15c-1, 15c-2... Fourier transform lens (also called generation unit), 16b, 16c-1, 16c-2... Phase control unit (also called control unit), 20a-1, 20a-2, 20a-3, 20b-1, 20b-2... Receiving device, 21b-1, 21b-2... Antenna, 22b-1, 22b-2... Wireless receiving unit, 23b-1, 23b-2... Signal processing unit, 24b-1, 24b-2... Feedback unit, 100a, 100b, 100c... Communication system

Claims

1. A transmitting device comprising: a generation unit that generates a first Airy beam by performing phase modulation and Fourier transform on a signal to be transmitted to at least one receiving device; and a control unit that controls a first angle for illuminating the first side lobe of the first Airy beam by performing a coordinate transformation based on a linear transformation on the phase distribution of the phase-modulated signal.

2. The transmitting device according to claim 1, wherein the control unit controls the first angle based on at least one of the position information of the at least one receiving device and the received power information of the at least one receiving device.

3. The transmitting device according to claim 1, wherein the generation unit generates the first Airy beam based on irradiation information of the second Airy beam generated by another transmitting device, so as not to overlap with the second Airy beam.

4. A transmission method comprising: a generation process that generates an Airy beam by performing phase modulation and Fourier transform on a signal to be transmitted to at least one receiving device; and a control process that controls the angle at which the side lobes of the Airy beam are irradiated by performing a coordinate transformation based on a linear transformation on the phase distribution of the phase-modulated signal.

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