Power supply system and power supply method

Abstract

To provide a power supply system and a power supply method capable of quickly setting a phase capable of increasing the received power of a power receiving device.SOLUTION: A power supply system includes: a power supply device; and a first power receiving device that receives a power transmission signal transmitted from the power supply device. The power supply device has: an array antenna that has a plurality of antennas capable of transmitting power; and a power transmission control unit that controls a phase of a power transmission signal transmitted from the plurality of antennas to the first power receiving device and controls the power transmission. The plurality of antennas are divided into a plurality of groups, and each of the groups includes the plurality of antennas. Antennas included in N groups (N is an integer equal to or greater than 2) out of the plurality of groups form an antenna subset that transmits the power transmission signal to the first power receiving device, and the first power receiving device selects superordinate N groups having larger received power of the power transmission signal as groups that form the antenna subset.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a power supply system and a power supply method. [Background technology]

[0002] Conventionally, there are power supply devices that include a first detection means for detecting the direction of a power receiving device, a first radiation that wirelessly radiates power in the direction of the power receiving device detected by the first detection means, and a second radiation that wirelessly radiates power while changing the direction of the radiated power within a defined range (see, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2019-083648 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] By the way, conventional power supply equipment does not manage to supply power to a specific power receiving device that requires a large amount of power, while simultaneously supplying power to other power receiving devices when supplying power to multiple power receiving devices.

[0005] Therefore, the objective is to provide a power supply system and power supply method that can simultaneously supply power to specific power receiving devices that require a large amount of power, and to power receiving devices other than those specific devices. [Means for solving the problem]

[0006] A power supply system according to an embodiment of the present invention is a power supply system including a power supply device and a first power receiving device that receives a power transmission signal transmitted from the power supply device, wherein the power supply device includes an array antenna having a plurality of antennas capable of transmitting power, and a power transmission control unit that controls the phase and transmission of the power transmission signal transmitted from the plurality of antennas to the first power receiving device, wherein the plurality of antennas are divided into a plurality of groups, each group includes a plurality of the antennas, and N (N is an integer of 2 or more) of the plurality of groups include antennas that constitute an antenna subset that transmits the power transmission signal to the first power receiving device, and the first power receiving device selects the top N groups with large received power of the power transmission signal as the groups that constitute the antenna subset. [Effects of the Invention]

[0007] This invention provides a power supply system and method that can simultaneously supply power to specific power receiving devices that require a large amount of power, and to power receiving devices other than those specific devices. [Brief explanation of the drawing]

[0008] [Figure 1] This figure shows a power supply system 300 according to an embodiment. [Figure 2A] This figure shows an example of the configuration of specific device 50A. [Figure 2B] This figure shows an example of the data structure of a packet transmitted by the communication unit 59 to the power supply device 100. [Figure 3] This diagram shows the configuration of the control device 140. [Figure 4] This figure shows an example of a WF code table. [Figure 5A] This figure shows an example of index assignment to 64 antenna elements 111. [Figure 5B] This figure shows an example of index assignment to 64 antenna elements 111. [Figure 5C] This figure shows an example of index assignment to 64 antenna elements 111. [Figure 5D] It is a diagram showing an example of the average distance between antenna elements 111 for each group index. [Figure 6A] It is a diagram showing the group indices of four antenna elements 111 in a 2×2 arrangement. [Figure 6B] It is a diagram showing the group indices of four antenna elements 111 in a 2×2 arrangement. [Figure 7] It is a diagram showing an example of a frame structure. [Figure 8] It is a diagram for explaining an example of an optimization process. [Figure 9A] It is a diagram for explaining the optimization of the phase of a power transmission signal received by a specific device 50A. [Figure 9B] It is a diagram for explaining the optimization of the phase of a power transmission signal received by a specific device 50A. [Figure 9C] It is a diagram for explaining the optimization of the phase of a power transmission signal received by a specific device 50A. [Figure 9D] It is a diagram for explaining the optimization of the phase of a power transmission signal received by a specific device 50A. [Figure 10] It is a flowchart showing an example of the processes executed by the control device 140 of the power supply system 300 and the specific device 50A. [Figure 11] It is a diagram for explaining an example of simulation conditions. [Figure 12A] It is a diagram showing an example of a simulation result of received power when transmitting with random beamforming for comparison. [Figure 12B] It is a diagram showing an example of a simulation result of the power supply system 300.

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments to which the power supply system, the power supply system, and the power supply method of the present invention are applied will be described.

[0010] <Embodiment> <Power Supply System 300> Figure 1 shows a power supply system 300 according to an embodiment. The power supply system 300 includes a power supply device 100 and a specific device 50A. The specific device 50A is an example of a power receiving device. The following explanation will use the XYZ coordinate system. Plane view refers to the XY plane view. The power supply system 300 may also include the power supply device 100 and a plurality of devices 50. The plurality of devices 50 include the specific device 50A and a plurality of non-specific devices 50B other than the specific device 50A.

[0011] The power supply device 100 is, for example, placed in an area 10 of a large-scale facility such as a smart factory, a large-scale plant, a logistics center, or a warehouse. The power supply device 100 includes an array antenna 110, a phase shifter 120, a microwave source 130, and a control device 140, and provides contactless power (microwave power supply) to multiple devices 50 located within the area 10. The power supply method of this embodiment is a power supply method realized by the power supply device 100, and is particularly realized by processing performed by the control device 140.

[0012] When the power supply device 100 supplies power to an unspecified number of devices 50, it causes the array antenna 110 to transmit power using beamforming. The multiple antenna elements 111 of the array antenna 110 can transmit power at a transmission phase specified by the power transmission control unit, which will be described later. If the phase of the transmission signals output by the multiple antenna elements 111 is fixed, a standing wave will be generated in the region 10 by the beam formed from the multiple antenna output signals, and devices 50 located at the nodes of the standing wave will receive almost no power. To avoid this situation, the power supply device 100 randomly shifts the phases of the multiple transmission signals output from the multiple antenna elements 111 in a time series so that the nodes of the standing wave do not occur in a specific location for a long period of time. In other words, the nodes of the standing wave are made to move within the region 10. The phase of the transmission signals is shifted according to the time slot. The transmission signal is a signal transmitted from the antenna elements 111 and is an RF (Radio Frequency) signal with a predetermined power. The frequency of the power transmission signal is, for example, 918 MHz.

[0013] Transmitting power using a beam formed by randomly shifting the phases of multiple transmission signals output from multiple antenna elements 111 according to time slots will be referred to as random beamforming below.

[0014] Furthermore, among the multiple devices 50, there may be some devices 50 that require more power to charge their internal batteries 54. For example, a device 50 that consumes more power than other devices 50 and has a low remaining charge in its internal battery 54. Such a device 50 that requires more power is referred to as a specific device 50A. Figure 1 shows one device 50 at a certain point in time as a specific device 50A. Specific device 50A is an example of the first power receiving device.

[0015] The specific device 50A primarily receives power from multiple antenna elements 111 included in antenna subset 110A of the multiple antenna elements 111. This is to charge the battery 54 of the specific device 50A more quickly by transmitting power more intensively than with random beamforming.

[0016] The power transmission from the multiple antenna elements 111 included in antenna subset 110A to the specific device 50A has a phase set for each frame. In Figure 1, antenna subset 110A includes four antenna elements 111. The phase shift of the power transmission signals to antenna subset 110A and the specific device 50A will be described later.

[0017] Of the multiple devices 50, all but the specific device 50A are referred to as non-specific devices 50B. All devices 50 can become the specific device 50A depending on the circumstances. When the battery 54 is sufficiently charged, the specific device 50A will no longer receive concentrated power from the antenna subset 110A and will become a non-specific device 50B. A non-specific device 50B is an example of a second power receiving device. The non-specific device 50B receives power from the antenna elements 111, including the antenna subset 110A, via random beamforming.

[0018] Furthermore, the specific device 50A may be mounted on a remotely manageable mobile vehicle such as an Automatic Guided Vehicle (AGV) or an Autonomous Mobile Robot (AMR), and may be mobile. All of the multiple devices 50 may be mounted on such a mobile vehicle and capable of becoming the specific device 50A depending on the situation, or only some of the multiple devices 50 may be mounted on such a mobile vehicle and capable of becoming the specific device 50A depending on the situation. Below, an example of a configuration in which the specific device 50A is mounted on a mobile vehicle and is mobile will be described.

[0019] The power supply device 100 is a power supply device that enables both power transmission to an unspecified device 50B by random beamforming and power transmission to a specified device 50A from an antenna subset 110A. In the following, unless otherwise specified, the specified device 50A and the unspecified device 50B will simply be referred to as device 50.

[0020] Furthermore, as an example, the following describes a configuration in which the array antenna 110 has 64 antenna elements 111. To simplify the selection process of selecting antenna elements 111 to be included in the antenna subset 110A from among the 64 antenna elements 111, the feeding system 300 divides the 64 antenna elements 111 into 16 groups. Each group has 4 antenna elements 111. Each of the 16 groups is assigned a group index from 1 to 16.

[0021] <Configuration of specific device 50A> Figure 2A shows an example of the configuration of a specific device 50A. The specific device 50A includes an antenna 51, a switch SW, a control unit 52, an RF / DC (Direct Current) conversion unit 53, a battery 54, a quadrature detection unit 55, a channel estimation unit 56, a subset selection unit 57, a potential-receiving phase estimation unit 58, and a communication unit 59. The communication unit 59 includes an antenna 59A.

[0022] Antenna 51 is an antenna for receiving power from one or more antenna elements 111. Antenna 51 outputs the received power to switch SW. Switch SW is switched by control unit 52 to switch the connection destination of antenna 51 to either RF / DC converter 53 or quadrature detection unit 55.

[0023] The control unit 52 switches the switch SW during the optimization period and the power supply period in each frame. During the optimization period, the control unit 52 switches the switch SW to connect to the quadrature detection unit 55, and during the power supply period, it switches the switch SW to connect to the RF / DC conversion unit 53.

[0024] During the optimization period, the control unit 52 instructs the quadrature detection unit 55, channel estimation unit 56, subset selection unit 57, potential-receiving phase estimation unit 58, and communication unit 59 to transmit data representing the potential-receiving phase obtained by the potential-receiving phase estimation unit 58 to the control device 140 of the power supply device 100.

[0025] Furthermore, during the power supply period, the control unit 52 performs charging control to charge the battery 54 with the power received from the antenna element 111 via the antenna 51.

[0026] The battery 54 is, for example, a secondary battery or a capacitor, and charges the power supplied from the antenna 51. The power charged in the battery 54 is used when the switch SW, control unit 52, RF / DC converter 53, quadrature detection unit 55, channel estimation unit 56, subset selection unit 57, potential-receiving phase estimation unit 58, and communication unit 59 operate.

[0027] A power-consuming load may be connected to the battery 54. For example, the load may be a sensor that detects temperature, humidity, etc., in which case the device 50 can be treated as a sensor device. Alternatively, the load may be a power source such as a motor or actuator, and the device 50 may be a device that performs dynamic work.

[0028] Furthermore, if the device 50 is attached to a mobile body, the power charged by the battery 54 can be used to drive power sources such as motors and control units of the mobile body, which is the load.

[0029] The RF / DC converter 53 is a converter (conversion circuit) that converts the power transmission signal (RF signal) received by the antenna 51 into DC power and outputs it to the battery 54.

[0030] The quadrature detection unit 55 demodulates the transmission signal received by the antenna 51 to extract the received sequence and outputs it to the channel estimation unit 56. The received sequence extracted by the quadrature detection unit 55 represents the combined amplitude and phase of the transmission signal received by the antenna 51. The received sequence is an example of demodulation information.

[0031] The channel estimation unit 56 calculates the channel estimate for each group based on the received sequence input from the quadrature detection unit 55 and the WF code for each group. The channel estimate has dimensions corresponding to voltage and phase and is expressed as a complex number. The WF code is a Walsh-Hadamard code, which is an example of a code table. The WF code will be described later using Figure 4.

[0032] The subset selection unit 57 calculates the power received by each group as the square of the absolute value of the channel estimate calculated for each group by the channel estimation unit 56. The subset selection unit 57 also performs a ranking process on the power received by all groups for each frame and selects a predetermined number of the top groups to be included in the antenna subset 110A. The subset selection unit 57 outputs the selection result representing the groups selected to be included in the antenna subset 110A to the potential-receiving phase estimation unit 58.

[0033] The ranking process selects groups up to -15dB below the group with the highest received power for all groups, as an example. For example, the subset selection unit 57 selects multiple groups for each frame that are ranked up to 15dB below the group with the highest received power. The number of groups included in the antenna subset 110A in each frame is determined by the number of groups up to 15dB below the highest received power, and therefore may vary from frame to frame.

[0034] The potential-receiving phase estimation unit 58 calculates the channel estimate value for the group included in the antenna subset 110A based on the selection result input from the subset selection unit 57, and outputs the potential-receiving phase (angle information) represented by the calculated channel estimate value to the communication unit 59 along with the selection result.

[0035] The communication unit 59 transmits the selection result and the received phase output from the received phase estimation unit 58 to the power supply device 100 via the antenna 59A. The selection result output from the received phase estimation unit 58 to the communication unit 59 is the selection result output by the subset selection unit 57 to the received phase estimation unit 58.

[0036] Although the configuration of the specific device 50A was explained using Figure 2A, among the multiple devices 50, devices 50 that do not become the specific device 50A but only function as non-specific devices 50B do not need to have a switch SW, quadrature detection unit 55, channel estimation unit 56, subset selection unit 57, potential-receiving phase estimation unit 58, and communication unit 59, and the control unit 52 only needs to control the charging of the battery 54.

[0037] Before describing the array antenna 110 shown in Figure 1, we will first explain the data structure of the packets transmitted by the communication unit 59 to the power supply device 100 using Figure 2B. Figure 2B shows an example of the data structure of the packets transmitted by the communication unit 59 to the power supply device 100.

[0038] Figure 2B shows that each packet includes a group index and a receiving phase, ranked from 1st to 3rd in terms of received power. As an example, Figure 2B shows the group indices and receiving phases for the 1st to 3rd ranked packets as Group Index #1 and Receiving Phase #1, Group Index #2 and Receiving Phase #2, and Group Index #3 and Receiving Phase #3. If there are groups ranked 4th or lower, the group index and receiving phase will follow the 3rd ranked group index #3 and receiving phase #3.

[0039] <Array Antenna 110> As shown in Figure 1, the array antenna 110 is an example of a two-dimensional antenna grid and includes, as an example, antenna elements 111 arranged in a matrix. For example, there are 64 antenna elements 111, with 8 in the X direction and 8 in the Y direction. The 64 antenna elements 111 are located on the XY plane. As described above, the 64 antenna elements 111 are divided into 16 groups.

[0040] Each antenna element 111 is connected to a microwave source 130 via a power transmission cable 130A, and is supplied with microwave power. Controlled by the control device 140, the antenna elements 111 belonging to multiple groups selected to constitute the antenna subset 110A from among the 16 groups transmit power with an optimized phase toward a specific device 50A, but also secondarily supply power to an unspecified device 50B located near the specific device 50A.

[0041] Antenna elements 111 that are not included in any of the groups selected to constitute the antenna subset 110A transmit power to the unspecified device 50B by random beamforming, but are also secondarily supplied by antenna elements 111 located relatively close to the specific device 50A. The number of groups included in the antenna subset 110A can be any number, as long as there are multiple groups.

[0042] Each group has four antenna elements 111. For example, if four groups are selected to constitute an antenna subset 110A, there will be four antenna subsets 110A, each containing four antenna elements 111. However, by performing the processing described later, it is possible to narrow down the antenna subset 110A that transmits power with an optimized phase toward a specific device 50A to just one. That is, as shown in Figure 1, there is only one antenna subset 110A that transmits power with an optimized phase toward a specific device 50A.

[0043] The antenna element 111 is a rectangular patch antenna in plan view. The antenna element 111 may have a ground plate held at ground potential on the -Z direction side.

[0044] Furthermore, as a specific device 50A moves, the antenna elements 111 constituting the antenna subset 110A are reviewed for each frame, and the antenna elements 111 included in the antenna subset 110A are selected.

[0045] Each antenna element 111 is mounted on the ceiling, pillars, etc., of a large-scale facility such as the smart factory mentioned above. The spacing between each antenna element 111 corresponds, for example, to several wavelengths in the communication frequency of the antenna element 111. The communication frequency of the antenna element 111 is assumed to be in the microwave band, for example, 918 MHz.

[0046] Furthermore, Figure 1 shows, as an example, a state in which a specific device 50A receives power from four of the 64 antenna elements 111 included in the array antenna 110. In this way, the set of multiple antenna elements 111 selected by the control device 140 to supply power to the specific device 50A is called the antenna subset 110A. Antenna elements 111 not included in the antenna subset 110A transmit power by random beamforming while shifting the phase of the transmission signal according to the time slot, and the power transmitted by random beamforming is received by the non-specific device 50B, but is also secondarily received by the specific device 50A.

[0047] Each phase shifter 120 is connected to each antenna element 111 and inserted between each antenna element 111 and the power transmission cable 130A. For ease of explanation, Figure 1 shows a magnified view of one antenna element 111 and the phase shifter 120.

[0048] The phase shifter 120 shifts the transmission phase of the power transmitted from the microwave source 130 via the power transmission cable 130A and outputs it to the antenna element 111. The phase shifter 120 is an example of a phase adjustment unit.

[0049] The microwave source 130 is connected to 64 phase shifters 120 and supplies microwaves of a predetermined power. The microwave source 130 is an example of a radio wave source. The microwave frequency is 918 MHz, for example. Although this description describes a configuration in which the power supply device 100 includes the microwave source 130, it is not limited to microwaves; any radio wave of a predetermined frequency will suffice.

[0050] The control device 140 is an example of a control unit and is a microcomputer having a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), and non-volatile memory, etc., and as an example, discrete wavelet multitone (DWMT) can be used.

[0051] The control device 140 has an antenna 140A and receives a beacon signal from a specific device 50A in which the received phase and selection result are written.

[0052] The control device 140 performs a subset setting process to set the antenna subset 110A based on the selection result received from a specific device 50A, phase control of 64 phase shifters 120 based on the received potential phase received from the specific device 50A, and power output control of the microwave source 130. Phase control of the transmission signals of the antenna elements 111 included in the antenna subset 110A and phase control of the transmission signals of the antenna elements 111 not included in the antenna subset 110A by random beamforming are achieved by phase control in the phase shifters 120.

[0053] <Control device 140> Figure 3 shows the configuration of the control device 140. The control device 140 has a main control unit 141, a power transmission control unit 142, and a memory 143. The main control unit 141 and the power transmission control unit 142 represent the functions of the program executed by the control device 140 as functional blocks. The memory 143 functionally represents the memory of the control device 140.

[0054] The main control unit 141 is a processing unit that oversees the processing of the control device 140, and executes processing other than the processing executed by the power transmission control unit 142.

[0055] The power transmission control unit 142 performs subset setting processing for setting the antenna elements 111 included in the antenna subset 110A based on the selection result received from the specific device 50A, phase control for controlling the phases of the 64 phase shifters 120 based on the received power phase received from the specific device 50A, and output control of the power of the microwave generation source 130.

[0056] When the antenna subset 110A is not set, the power transmission control unit 142 performs power transmission control for transmitting power from all the antenna elements 111. When transmitting power from all the antenna elements 111, the power transmission control unit 142 randomly sets the phases of the power transmission signals of all the antenna elements 111, and performs power transmission control by random beamforming that randomly shifts the phases for each time slot (random mode). Thereby, it is possible to prevent the position where the standing wave of the power transmission signal occurs in the area 10 (see FIG. 1) from being fixed in time, and all the devices 50 can receive power relatively evenly.

[0057] Also, when the antenna subset 110A is constructed, the power transmission control unit 142 performs optimization processing during the optimization period in each frame and power supply processing during the power supply period of each frame. The optimization processing during the optimization period and the power supply processing during the power supply period will be described later.

[0058] The memory 143 stores data, programs, etc. used when the main control unit 141 and the power transmission control unit 142 execute processing. Data representing the phases of the power transmission signals in each time slot is also stored in the memory 143.

[0059] <WH (Walsh-Hadamard) code table> Figure 4 shows an example of a WF code table. Figure 4 shows the code values ​​generated for time slots 1 to 16 for group indices 1 to 16. In Figure 4, code value 1 represents a phase shift of 0 degrees, and code value -1 represents a phase shift of 180 degrees. That is, code value 1 and code value -1 differ in phase shift by 180 degrees (π).

[0060] Using such a code table, the transmitting phase of the 16 groups of antenna elements 111 is shifted, and the group to be included in the antenna subset 110A and the receiving phase are estimated. The number of time slots is set to 16 as an example to allow the phase shift amount of the 16 groups to be changed 16 times. The number of time slots may be less than or more than 16, but it is preferable that it be an integer multiple of the number of groups.

[0061] <Grouping> Figures 5A to 5C show an example of index assignment to 64 antenna elements 111. Figures 5A to 5C show an example of index assignment to 64 antenna elements 111 arranged in an 8x8 pattern in the X and Y directions.

[0062] Figure 5A shows an example of the result of regularly assigning indices from 1 to 64 to 64 antenna elements 111. Indices from 1 to 64 are assigned sequentially from the corner on the -X and +Y sides to the corner on the +X and -Y sides. The same number of indices as the number of antenna elements 111 are required, and since the number of code values ​​is 64 and the code length is 64, the overhead increases. In addition, the amount of computation increases because the receiving side needs to process the received signal sequence of 64 time slots.

[0063] Figures 5B and 5C show the group index assignment results when 64 antenna elements 111 are divided into 16 groups. Since each group contains 4 antenna elements 111, there are 4 identical group indices in Figures 5B and 5C. The transmitting phase of 4 antenna elements 111 with the same group index is set to the same transmitting phase.

[0064] Figure 5B shows the results of assigning group indices to each area, where the 64 antenna elements 111 are divided into four areas (each containing 16 antenna elements in a 4x4 grid) by straight lines parallel to the X and Y axes passing through the centers of the 64 antenna elements 111, and group indices from 1 to 16 are regularly placed as indices for each area.

[0065] Compared to the case in Figure 5A, the number of sign values ​​is reduced to 1 / 4, or 16, thus reducing the overhead by 1 / 4. The minimum distance between antenna elements 111 assigned the same group index is 8.0m, assuming a distance of 2.0m between adjacent antenna elements 111, making them less likely to influence each other.

[0066] However, for example, if four antenna elements 111 with group indices 6, 7, 10, and 11 exist in each area in a 2x2 arrangement, and all four antenna elements 111 are identically arranged, then, for example, if an antenna subset 110A that transmits power with a phase optimized for a specific device 50A includes antenna elements 111 from four groups with group indices 6, 7, 10, and 11, and the four antenna elements 111 are arranged in a 2x2 arrangement, then it is impossible to distinguish the beams obtained by beamforming in the four antenna subsets 110A. In other words, it is impossible to narrow down the antenna subset 110A that transmits power with a phase optimized for a specific device 50A to just one. Therefore, one of the four antenna subsets 110A can transmit power with a phase optimized for a specific device 50A, but the remaining three antenna subsets 110A will transmit beam-shaped power signals towards locations where the specific device 50A does not exist, generating unnecessary strong electric field areas.

[0067] Therefore, in the power supply system 300, 16 group indices are randomly assigned to the 64 antenna elements 111, as shown in Figure 5C. In Figure 5C, antenna elements 111 assigned the same group index maintain a certain distance from each other. For example, if the group indices of the group selected to be included in antenna subset 110A are 12, 6, 5, and 2, and the antenna subset 110A selected to transmit a power transmission signal to a specific device 50A includes four antenna elements 111 arranged in a 2x2 configuration with group indices 12, 6, 5, and 2, as indicated by the dark dots on the +X and +Y sides.

[0068] In this case, as shown in Figure 5C, 16 group indices are randomly assigned to the 64 antenna elements 111. Therefore, the remaining three antenna subsets 110A, as indicated by the faint dots, do not have the four antenna elements 111 with group indices 12, 6, 5, and 2 arranged in a 2x2 configuration.

[0069] Antenna subset 110A, including the 12, 6, 5, 2 in a 2x2 arrangement shown by the dark dots, can transmit a beam-shaped power signal with an optimized transmitting phase directed toward a specific device 50A. More specifically, it can transmit the power signal by random beamforming while maintaining the optimized transmitting phase. However, the three antenna subsets 110A, including the 12, 6, 5, 2 in a light dot arrangement, are not in a 2x2 arrangement, and therefore, even though they include the 12, 6, 5, 2 group indices, the phase of the combined power signal is not optimized, thus suppressing the generation of unnecessary strong electric field areas.

[0070] Furthermore, in each of the remaining three antenna subsets 110A, the transmission signal is transmitted by random beamforming from the antenna elements 111 located around the four antenna elements 111, thereby randomizing the multipath for each time slot, and thus further suppressing the continuation of strong electric fields.

[0071] The reason for setting a large distance between antenna elements 111 that are assigned the same group index is that if the transmission signals transmitted by multiple antenna elements 111 that are assigned the same group index reach the antenna of a specific device 50A in opposite phase, the transmission signals will cancel each other out. However, by increasing the distance, even if the signals are in opposite phase, the amplitude difference becomes larger, making cancellation less likely.

[0072] Figure 5D shows an example of the average distance between antenna elements 111 for each group index. As shown in Figure 5C, when 16 group indices are randomly assigned to 64 antenna elements 111, Figure 5D shows the average distance between two of the four antenna elements 111 in each group. As shown in Figure 5D, a distance of 6.3m or more was obtained for all groups 1 to 16, confirming that sufficient distance is maintained between the four antenna elements 111 in each group.

[0073] As shown in Figure 5C, in order to randomly assign 16 group indices to 64 antenna elements 111, it is necessary to maintain randomness while keeping a sufficient distance between the four antenna elements 111 in each group.

[0074] Furthermore, when randomly assigning 16 group indices to 64 antenna elements 111, in order to suppress the generation of multiple antenna subsets 110A that include antenna elements 111 with group indices 6, 7, 10, and 11, as shown in Figure 5B, the following processing can be performed.

[0075] Figures 6A and 6B show the group indices of four antenna elements 111 arranged in a 2x2 configuration. For example, suppose the group indices of the four antenna elements 111 included in a given 2x2 configuration are X, A, B, and C. In this case, if group index X is replaced with group index Y, the eight 2x2 configuration patterns shown in Figure 6B will not occur. To prevent this, 16 group indices can be randomly assigned to the 64 antenna elements 111. Figure 6B shows eight 2x2 configuration patterns, including those with group indices Y, A, B, and C.

[0076] If at least one of the group indices shown in Figure 6A (a 2x2 arrangement of X, A, B, C) and the eight 2x2 arrangements shown in Figure 6B (group indices Y, A, B, C) is included in the group indices of the 64 antenna elements 111, then when group index X and group index Y are equal, multiple antenna subsets 110A containing the same four group indices will be generated, making it impossible to narrow down to a single antenna subset 110A that transmits power with an optimized phase toward a specific device 50A.

[0077] <Frame Structure> Figure 7 shows an example of a frame structure. The frame duration is, in an example, 50 ms. The frame includes an optimization period and a power supply period. The power supply period is provided after the optimization period.

[0078] The optimization period is the time during which the transmitting phase is set for each of the multiple groups based on the WF code table (Figure 4), and the transmitting phase of the multiple groups included in the antenna subset 110A that transmits the power transmission signal to a specific device 50A is optimized.

[0079] Optimizing the transmission phases of multiple groups included in the antenna subset 110A that transmits a transmission signal to a specific device 50A means aligning the phases (receiving phases) when the transmission signals transmitted by the antenna elements 111 of multiple groups selected by the specific device 50A as groups included in the antenna subset 110A are received by the antenna 51 of the specific device 50A. This is because aligning the receiving phases of multiple transmission signals maximizes the power received by the specific device 50A. Note that aligning the phases does not necessarily mean that the phases are exactly the same, but also includes a state that is approximately equal to the state of being exactly the same. In a strict sense, aligning the phases is not always easy, and for example, if the phase difference is around ±5%, it is acceptable to consider the phases as aligned.

[0080] As explained using Figure 5C, in this example, each group contains four antenna elements 111, so the transmission phase is optimized in the four antenna subsets 110A. However, since the antenna elements 111 of the group included in antenna subset 110A are arranged in a 2x2 configuration in only one of the four antenna subsets 110A, it is possible to narrow down the antenna subset 110A that transmits power with a phase optimized for a specific device 50A to just one.

[0081] The feeding period is the period during which the feeding process is performed to transmit power signals from multiple groups of antenna elements 111, with the phase of the transmission signals transmitted by multiple groups of antenna elements 111 optimized during the optimization process in the optimization period. During the feeding period, random beamforming is performed on multiple groups of antenna elements 111 included in antenna subset 110A, while maintaining the relationship between the transmitting phases of multiple groups included in antenna subset 110A, which was obtained during the optimization process in the optimization interval within the same frame. For multiple groups of antenna elements 111 not included in antenna subset 110A, random beamforming is performed without any particular relationship between the transmitting phases of each group of antenna elements 111. Note that for multiple groups of antenna elements 111 not included in antenna subset 110A, random beamforming may be performed without any particular relationship between the transmitting phases of multiple antenna elements 111, regardless of the group.

[0082] <Optimization of the potential transmission phase> From each antenna element 111, a power transmission signal transmitted with a common (identical) transmission phase for each group undergoes a phase shift according to the path difference and reaches the antenna 51 of the specific device 50A.

[0083] The quadrature detection unit 55 demodulates the transmission signal received by the antenna 51 to obtain the received sequence r(l) (l = 1, …, N S Extract the time slot. l is the index of the time slot, and the maximum value is Ns. Here, as an example, Ns is 16.

[0084] The channel estimation unit 56 calculates the estimated channel value for each group based on the received sequence input from the quadrature detection unit 55 and the WF code for each group (see Figure 4). The WF code for each group is W = w(g, l), (g = 1, …, N G ) g is the group index, and N G This is the maximum value of the group index. Here, as an example, N G It is 16.

[0085] The channel estimation unit 56 calculates the channel estimate h for the group of group index g according to the following equation (1): g Calculate.

[0086]

number

[0087] The subset selection unit 57 selects the channel estimate h g The square of the absolute value of is the received power p received by the antenna 51 of specific device 50A from the antenna element 111 of group index g. R, g It is calculated according to the following formula (2).

[0088]

number

[0089] Furthermore, the subset selection unit 57 performs a ranking process for the received power of all groups for each frame and selects a predetermined number of top-ranking groups to be included in the antenna subset 110A. Specifically, as an example, it selects groups up to -15dB from the group with the highest received power. The subset selection unit 57 outputs the selection result, which represents the groups selected to be included in the antenna subset 110A, to the potential-receiving phase estimation unit 58.

[0090] The potential-receiving phase estimation unit 58 estimates the channel values ​​h of multiple groups included in the antenna subset 110A based on the selection result input from the subset selection unit 57. s This is calculated according to equation (3) below. Here, s is the group index of the multiple groups included in antenna subset 110A.

[0091] For example, as shown in FIG. 5C, when the antenna subset 110A includes four groups with group indices g of 12, 6, 5, and 2, the group indices s of the plurality of groups included in the antenna subset 110A are 12, 6, 5, and 2.

[0092] Channel estimation value h s is the channel estimation value for the group with group index s. The channel estimation value h s is calculated for each group with group index s.

[0093]

Number

[0094] The power reception phase estimation unit 58 calculates the power reception phase Δθs when the antenna 51 of the specific device 50A receives power from the antenna element 111 of the group with group index s according to the following equation (4) based on the channel estimation value h represented by equation (3). s The power reception phase estimation unit 58 outputs the power reception phase for each group with group index s to the communication unit 59 together with the selection result (group index s). The communication unit 59 transmits the selection result and the reception phase for each group with group index s to the power supply device 100.

[0095]

Number

[0096] The power reception phase estimation unit 58 outputs the power reception phase for each group with group index s to the communication unit 59 together with the selection result (group index s). The communication unit 59 transmits the selection result and the reception phase for each group with group index s to the power supply device 100.

[0097] The power transmission control unit 142 sets the initial value of the transmitting phase of the antenna element 111 of the group with group index s to φs according to equation (5) below, based on the selection result and received phase returned from the specific device 50A. In this way, the transmitting phase of the antenna element 111 of the group included in the antenna subset 110A is optimized. The transmitting phase φs (initial value) is set for each group of group index s. If the group index s is 12, 6, 5, or 2, the transmitting phase φs corresponding to the group index is set for each of the groups with group index s of 12, 6, 5, or 2.

[0098]

number

[0099] In this way, by optimizing the transmission phase of the antenna elements 111 of the group included in antenna subset 110A, the transmission signals transmitted from the antenna elements 111 of the group with group index s are in phase when the antenna 51 of the specific device 50A receives power, and the received power is maximized.

[0100] <Optimization Process> Figure 8 illustrates an example of the optimization process. Figure 8 shows the optimization period, power supply period, and time slots within one frame. The optimization process involves Ns time slots. The power supply period begins at time slot Ns+1 and is longer than the optimization period, but is shown here in a simplified manner.

[0101] The group index g of the group of antenna elements 111 included in the array antenna 110 is set from 1 to N. G Let's assume that in time slot 1, the group index g is 1 to N. G The transmitting phase of the antenna element 111 is θ1 to θN G Set to this. In this state, start transmitting the power transmission signal. Note that the transmission potential phases θ1 to θN G This is an arbitrary potential-transmitting phase.

[0102] From time slot 2 onward, the transmitting phase of each group of antenna elements 111 is set according to the WH code table. For example, in time slot 2, the transmitting phase of the antenna elements 111 of groups with even group index g is shifted by 180 degrees (+π) relative to the transmitting phase in time slot 1. In this way, the transmitting phase of each group of antenna elements 111 is shifted according to the WH code table for each time slot. Note that in time slots 1 to Ns, the transmitting phase of the antenna elements 111 of group index 1 is fixed at θ1.

[0103] Furthermore, during the power supply period, it is assumed that the four groups included in antenna subset 110A are group indices 1 to 4. Also, the group indices g of the groups not included in antenna subset 110A are assigned as 5, ..., N. G Let's assume that.

[0104] For the antenna elements 111 of the group indices 1 to 4 included in antenna subset 110A, the transmitting phase of the antenna elements 111 of the group indices 1 to 4 is set to the optimized transmitting phases φ1 to φ4, and random beamforming is performed while maintaining the optimized relationship between the transmitting phases φ1 to φ4. As an example, random beamforming is performed while maintaining the optimized relationship between the transmitting phases φ1 to φ4 by shifting the transmitting phase of the antenna elements 111 of the group indices 1 to 4 by Δ1, Δ2, Δ3, ... for each time slot.

[0105] Furthermore, during the power supply period, random beamforming is performed on antenna elements 111 of groups not included in antenna subset 110A, without any particular relationship between the transmitting phases of multiple antenna elements 111 within each group. The power supply period is an example of a power supply period. Note that for multiple groups of antenna elements 111 not included in antenna subset 110A, random beamforming may be performed regardless of the group, without any particular relationship between the transmitting phases of multiple antenna elements 111.

[0106] <Potential receiving phase of the power transmission signal for a specific device (50A)> Figures 9A to 9D illustrate the optimization of the phase of the transmission signal received by a specific device 50A. The I axis is the real axis, and the Q axis is the imaginary axis.

[0107] Figure 9A shows the transmission phases θ1 to θ4 of the power transmission signal transmitted from the antenna elements 111 of group indices 1 to 4 in time slot 1 of the optimization interval. Since the transmission phases θ1 to θ4 are arbitrary transmission phases, for clarity, all transmission phases θ1 to θ4 are set to 0 degrees. The four vectors (1) to (4) in Figure 9A represent the power transmission signal transmitted from the antenna elements 111 of group indices 1 to 4 as vectors.

[0108] Figure 9B shows the received potential phase when the antenna 51 of the specific device 50A receives the transmitted power signals θ1 to θ4 shown in Figure 9A. At antenna 51, the transmitted power signals transmitted from antenna elements 111 of group indices 1 to 4 are combined, but they are shown separately in Figure 9B. The four vectors (1) to (4) in Figure 9B represent the transmitted power signals transmitted from antenna elements 111 of group indices 1 to 4 and received by antenna 51 as vectors.

[0109] As shown in Figure 9B, the receiving phases when the antenna 51 of the specific device 50A receives the power transmission signal transmitted from the antenna elements 111 of group indices 1 to 4 are Δθ1 to Δθ4.

[0110] In such cases, to optimize the power transmission signals sent from the antenna elements 111 of group indices 1 to 4, the received potential phases should be aligned when the power transmission signals sent from the antenna elements 111 of group indices 1 to 4 are received by the antenna 51 of the specific device 50A.

[0111] Here, as shown in Figure 9C, if we assume that the optimized values ​​of the transmission signals sent from the antenna elements 111 of group indices 1 to 4 are φ1 to φ4, then we should set φ1 = -Δθ1, φ2 = -Δθ2, φ3 = -Δθ3, and φ4 = -Δθ4. The four vectors (1) to (4) in Figure 9C represent the transmission signals sent from the antenna elements 111 of group indices 1 to 4 as vectors.

[0112] When the power transmission signals φ1 to φ4 are optimized in this way and power is started during the power supply period, the received potential phase when the antenna 51 of the specific device 50A receives power will all coincide at 0 degrees, as shown in Figure 9D. The four vectors (1) to (4) in Figure 9D represent the power transmission signals transmitted from the antenna elements 111 of group indices 1 to 4 and received by the antenna 51 as vectors.

[0113] For the sake of clarity, the transmission phases θ1 to θ4 are all set to 0 degrees in this explanation. As shown in Figure 9D, the receiving phases when the antenna 51 of the specific device 50A receives power all coincide at 0 degrees. However, if, for example, the transmission phases θ1 to θ4 are all 45 degrees, then the receiving phases when the antenna 51 of the specific device 50A receives power will all coincide at 45 degrees.

[0114] In this way, as shown in Figure 9D, the angles of vectors (1) to (4) when the antenna 51 of the specific device 50A receives power can be aligned. That is, the power received by the specific device 50A can be maximized.

[0115] <Flowchart> Figure 10 is a flowchart illustrating an example of the processing performed by the control device 140 and the specific device 50A of the power supply system 300. Although the control device 140 and the specific device 50A perform processing separately, here they are described as a series of processes within the power supply system 300. The processing shown in Figure 10 is performed within a single frame and is performed similarly in each frame.

[0116] The power transmission control unit 142 of the power supply device 100 simultaneously transmits power transmission signals from all groups of antenna elements 111 (step S1). For example, power transmission is performed repeatedly over time slots 1 to Ns shown in Figure 8.

[0117] The channel estimation unit 56 of the specific device 50A calculates channel estimates for each group (step S2).

[0118] The subset selection unit 57 of the specific device 50A calculates the received power for each group based on the channel estimate, performs a ranking process based on the received power of all groups, and selects the group to be included in the antenna subset 110A (step S3).

[0119] The potential-receiving phase estimation unit 58 of the specific device 50A calculates the potential-receiving phase for each group included in the antenna subset 110A (step S4).

[0120] The potential-receiving phase estimation unit 58 of the specific device 50A transmits the potential-receiving phase for each group and the selection result to the communication unit 59 (step S5).

[0121] The power transmission control unit 142 of the power supply device 100 transmits a power transmission signal using random beamforming while maintaining an optimized transmission phase from the group of antenna elements 111 included in antenna subset 110A, and also transmits power using random beamforming from the group of antenna elements 111 not included in antenna subset 110A (step S6). As a result, the group of antenna elements 111 included in antenna subset 110A transmits a power transmission signal while shifting the optimized transmission phase by a predetermined phase for each time slot, while the group of antenna elements 111 not included in antenna subset 110A transmits a power transmission signal with a random transmission phase for each time slot.

[0122] The specific device 50A and the non-specific device 50B receive the power transmission signal via the antenna 51 (step S7).

[0123] When the processing in step S7 is completed, the frame ends (step S8). Once processing within a single frame is complete in step S8, the flow returns to step S1.

[0124] <Simulation> Figure 11 illustrates an example of simulation conditions. As an example, a simulation was performed in which 64 antenna elements 111 arranged in an 8x8 array were used to supply power to a specific device 50A. The specific device 50A moves along the trajectory of the dotted circle at a speed of 2.0 m / sec. The distance between antenna elements 111 is 2 m, the height of each antenna element 111 is 2.5 m, the time slot length is 0.5 ms (milliseconds), and the frame length is 50 ms.

[0125] In the simulation of the power supply system 300, the power received by all groups was ranked for each frame, and based on the ranking results, multiple antenna elements 111 included in antenna subset 110A were selected. Power was transmitted to the multiple antenna elements 111 included in antenna subset 110A using random beamforming while maintaining an optimized transmission phase relationship, and power was transmitted to the antenna elements 111 not included in antenna subset 110A using random beamforming. The amount of power received by a specific device 50A was then simulated.

[0126] Furthermore, for comparison, we also simulated the amount of power received by a specific device 50A when, instead of grouping the 64 antenna elements 111, we assigned a different index from 1 to 64 to each antenna element 111, provided 64 time slots in the optimization section, and transmitted power using random beamforming in the power supply section.

[0127] Figure 12A shows an example of simulation results for received power when transmitting power using a comparative random beamforming method. In Figure 12A, the horizontal axis represents time, and the vertical axis represents received power (dBm). When transmitting power using a comparative random beamforming method, the received power is approximately 0 dBm during the first 30 ms of each 50 ms frame, which corresponds to the optimization interval. The time slot length is 0.5 ms, and there are 64 time slots, so the optimization interval required 32 ms. The latter half of each frame, where a received power of approximately 5 dBm is obtained, corresponds to the power supply interval, but it is less than 20 ms, confirming that the optimization interval requires a long time.

[0128] Figure 12B shows an example of the simulation results for the power supply system 300. In Figure 12B, the horizontal axis represents time, and the vertical axis represents the received power (dBm).

[0129] As shown in Figure 12B, the period at the beginning of each frame where the received power is approximately 0 dBm is about 6 ms, which corresponds to the optimization interval. Compared to the comparative random beamforming shown in Figure 12A, the optimization interval is shortened to about 1 / 4, and the period during which a received power of approximately 5 dBm is obtained is approximately twice as long. Furthermore, although one group contains four antenna elements 111, the received power obtained is approximately the same as that in the feed interval of the comparative random beamforming shown in Figure 12A. Therefore, it was confirmed that the feed interval can be lengthened, and the received power of a specific device 50 A per unit time can be increased.

[0130] <Effects> The power supply system 300 includes a power supply device 100 and a specific device 50A that receives a power transmission signal transmitted from the power supply device 100. The power supply device 100 includes an array antenna 110 having a plurality of antenna elements 111 capable of transmitting power, and a power transmission control unit 142 that controls the phase of the power transmission signal transmitted from the plurality of antenna elements 111 to the specific device 50A and controls the power transmission. The plurality of antenna elements 111 are divided into a plurality of groups, each group containing a plurality of antenna elements 111. Antenna elements 111 included in N (N is an integer of 2 or more) of the plurality of groups form an antenna subset 110A that transmits a power transmission signal to the specific device 50A. The specific device 50A selects the top N groups with the largest received power of the power transmission signal as the groups that make up the antenna subset 110A. In this way, the multiple antenna elements 111 are divided into multiple groups, and the top N groups with large received power of the transmitted signal are selected as the groups to construct the antenna subset 110A, so that a phase that can increase the received power of a specific device 50A can be quickly set.

[0131] Therefore, it is possible to provide a power supply system 300 that can quickly set a phase that can increase the power received by a specific device 50A.

[0132] Furthermore, the power transmission control unit 142 transmits power signals from multiple antenna elements 111 while shifting the phase of the power transmission signals over multiple time slots, based on a code table in which code values ​​are randomly set over multiple time slots for each group. The specific device 50A receives the power transmission signals transmitted from the multiple antenna elements 111 over multiple time slots, and the specific device 50A determines the received power for each group. The specific device then selects the top N groups with the largest received power for each group to form the antenna subset 110A. In this way, the transmission phase can be randomly set for each group based on the code table, and the top N groups with the largest received power for each group are selected to form the antenna subset 110A. This makes it easy to set the transmission phase for each group and to easily select groups that can supply more power to the specific device 50A.

[0133] Furthermore, the specific device 50A obtains channel estimates for each group based on demodulation information obtained by demodulating the received transmission signal and code values ​​across multiple time slots included in the code table. Based on the N channel estimates for the N groups, the specific device 50A determines the receiving phase when it receives a transmission signal from each of the N groups, and notifies the transmission control unit 142 of the receiving phases for the N groups. The transmission control unit 142 then controls the transmitting phase for each group so that the receiving phases of the N groups are aligned when the specific device 50A receives power from the N groups, based on the receiving phases for the N groups notified by the specific device 50A. Based on the channel estimates, the receiving phase when the specific device 50A receives a transmission signal from each group can be easily determined, and the transmission control unit 142 can easily control the transmitting phase for each group so that the receiving phases of the specific device 50A are aligned, based on the notified receiving phases.

[0134] The power transmission control unit 142 determines the initial values ​​of the transmitting phases for N groups based on the receiving phases for N groups notified by the specific device 50A, and controls the transmitting phase of each group by adding a common random phase shift amount to the N initial values ​​for each time slot, so that the receiving phases are aligned when the specific device 50A receives power from the N groups. Therefore, the N groups can easily achieve random beamforming while maintaining the relationship between the initial values ​​of the N transmitting phases.

[0135] Furthermore, the system includes an unspecified device 50B that receives a power transmission signal from the power supply device 100, and the power transmission control unit 142 randomly sets the transmission phase of the antennas included in groups other than N groups out of the multiple groups for each time slot. Therefore, the unspecified device 50B can transmit power by random beamforming from the antenna elements 111 of groups not included in the antenna subset 110A.

[0136] Furthermore, the position of the non-specific device 50B is fixed. Therefore, the power transmission signal by random beamforming can be efficiently and evenly received from the group of antenna elements 111 that are not included in the antenna subset 110A.

[0137] Furthermore, the specific device 50A is mobile. Therefore, by setting initial values ​​for N transmission phases for N groups in each frame in accordance with the movement, random beamforming that maintains the relationship between the initial values ​​of the N transmission phases in each frame can efficiently supply power to the mobile specific device 50A.

[0138] The power supply method is a power supply method in a power supply system 300 including a power supply device 100 and a specific device 50A that receives a power transmission signal transmitted from the power supply device 100, wherein the power supply device 100 includes an array antenna 110 having a plurality of antenna elements 111 capable of transmitting power, and a power transmission control unit 142 that controls the phase of the power transmission signal transmitted from the plurality of antenna elements 111 to the specific device 50A and controls the power transmission, wherein the plurality of antenna elements 111 are divided into a plurality of groups, each group containing a plurality of antenna elements 111, and antennas included in N (N is an integer of 2 or more) of the plurality of groups form an antenna subset 110A that transmits a power transmission signal to the specific device 50A, and the specific device 50A selects the top N groups with large received power of the power transmission signal as the groups that constitute the antenna subset 110A. In this way, the multiple antenna elements 111 are divided into multiple groups, and the top N groups with large received power of the transmitted signal are selected as the groups to construct the antenna subset 110A, so that a phase that can increase the received power of a specific device 50A can be quickly set.

[0139] Therefore, it is possible to provide a power supply method that can quickly set a phase that can increase the power received by a specific device 50A.

[0140] Although exemplary embodiments of the power supply system, power supply system, and power supply method of the present invention have been described above, the present invention is not limited to the specifically disclosed embodiments, and various modifications and changes are possible without departing from the scope of the claims.

[0141] The following items are further disclosed regarding the embodiments described above. (Item 1) Power supply device and A first power receiving device that receives a power transmission signal transmitted from the aforementioned power supply device. A power supply system including, The power supply device is An array antenna having multiple antennas capable of transmitting power, A power transmission control unit that controls the phase of the power transmission signal transmitted from the plurality of antennas to the first power receiving device and performs power transmission control. It has, The aforementioned multiple antennas are divided into multiple groups, Each group includes a plurality of the aforementioned antennas, N (where N is an integer of 2 or more) antennas from among the aforementioned groups constitute an antenna subset that transmits the power transmission signal to the first power receiving device. The first power receiving device is a power supply system that selects the top N groups with large received power of the power transmission signal as groups to constitute the antenna subset. (Item 2) The power transmission control unit transmits the power transmission signal from the multiple antennas while shifting the phase of the power transmission signal over the multiple time slots, based on a code table in which code values ​​are randomly set over multiple time slots for each group. The power supply system according to item 1, wherein the first power receiving device determines the received power for each group when the first power receiving device receives the power transmission signals transmitted from the plurality of antennas over the plurality of time slots, and selects the top N groups with the largest received power for each group as groups to construct the antenna subset. (Item 3) The first power receiving device, Based on the demodulated information obtained by demodulating the received transmission signal and the code values ​​across the multiple time slots included in the code table, a channel estimate is obtained for each group. Based on the N channel estimates for the N groups, the receiving phase when the first power receiving device receives the power transmission signal from each of the N groups is determined. The receiving phase for the N groups is notified to the power transmission control unit, The power supply system according to item 2, wherein the power transmission control unit controls the power transmission phase for each of the N groups based on the power receiving phase for the N groups notified by the first power receiving device, so that the power receiving phases are aligned when the first power receiving device receives power from the N groups. (Item 4) The power supply system according to item 3, wherein the power transmission control unit determines the initial value of the transmitting phase for the N groups based on the receiving phase for the N groups notified by the first power receiving device, and controls the transmitting phase for each group so that the receiving phase is aligned when the first power receiving device receives power from the N groups by adding a common random phase shift amount to the N initial values ​​for the N groups for each time slot. (Item 5) The system further includes a second power receiving device that receives a power transmission signal transmitted from the aforementioned power supply device, The power transmission control unit randomly sets the transmission phase of antennas belonging to N groups other than the aforementioned group for each time slot, according to any one of items 2 to 4 of the power transmission control unit. (Item 6) The power supply system described in item 5, wherein the position of the second power receiving device is fixed. (Item 7) The first power receiving device is a portable power supply system as described in any one of items 1 to 6. (Item 8) Power supply device and A first power receiving device that receives a power transmission signal transmitted from the aforementioned power supply device. A power supply method in a power supply system including, The power supply device is An array antenna having multiple antennas capable of transmitting power, A power transmission control unit that controls the phase of the power transmission signal transmitted from the plurality of antennas to the first power receiving device and performs power transmission control. It has, The aforementioned multiple antennas are divided into multiple groups, Each group includes a plurality of the aforementioned antennas, N (where N is an integer of 2 or more) antennas from among the aforementioned groups constitute an antenna subset that transmits the power transmission signal to the first power receiving device. A power supply method in which the first power receiving device selects the top N groups of the transmission signal with the largest received power as groups that constitute the antenna subset. [Explanation of symbols]

[0142] 10 areas 50 devices 50A Specific Devices 50B Unspecified device 51 Antenna SW Switch 52 Control Unit 53 RF / DC Conversion Section 54 batteries 55. Quadrature detection section 56 Channel Estimation Unit 57 Subset Selection Section 58 Power reception phase estimator 59 Communications Department 100 Power supply device 110 Array Antenna 110A Antenna Subset 111 Antenna elements 120 Phase Shifter 130 Microwave Sources 140 Control device 141 Main Control Unit 142 Power transmission control unit 143 memory

Claims

1. Power supply device and A first power receiving device that receives a power transmission signal transmitted from the aforementioned power supply device. A power supply system including, The power supply device is An array antenna having multiple antennas capable of transmitting power, A power transmission control unit that controls the potential transmission phase of the power transmission signal transmitted from the plurality of antennas to the first power receiving device and performs power transmission control. It has, The aforementioned multiple antennas are divided into multiple groups, Each group includes a plurality of the aforementioned antennas, N (where N is an integer of 2 or more) antennas from among the plurality of groups constitute an antenna subset that transmits the power transmission signal to the first power receiving device. The first power receiving device is a power supply system that selects the top N groups with the largest received power of the power transmission signal as groups to constitute the antenna subset.

2. The power transmission control unit transmits the power transmission signal from the plurality of antennas while shifting the power transmission phase of the power transmission signal over the plurality of time slots, based on a code table in which code values ​​are randomly set over a plurality of time slots for each group. The power supply system according to claim 1, wherein the first power receiving device determines the received power for each group when the first power receiving device receives the power transmission signals transmitted from the plurality of antennas over the plurality of time slots, and selects the top N groups with the largest received power for each group as groups to construct the antenna subset.

3. The first power receiving device is Based on the demodulated information obtained by demodulating the received transmission signal and the code values ​​across the multiple time slots included in the code table, a channel estimate is obtained for each group. Based on the N channel estimates for the N groups, the receiving phase when the first power receiving device receives the power transmission signal from each of the N groups is determined. The receiving phase for the N groups is notified to the power transmission control unit, The power supply system according to claim 2, wherein the power transmission control unit controls the power transmission phase for each of the N groups based on the power receiving phase for the N groups notified by the first power receiving device, so that the power receiving phases are aligned when the first power receiving device receives power from the N groups.

4. The power supply system according to claim 3, wherein the power transmission control unit determines the initial value of the transmitting phase for the N groups based on the receiving phase for the N groups notified by the first power receiving device, and controls the transmitting phase for each group by adding a common random phase shift amount to the N initial values ​​for the N groups for each time slot, so that the receiving phase is aligned when the first power receiving device receives power from the N groups.

5. The system further includes a second power receiving device that receives the power transmission signal transmitted from the power supply device, The power transmission control unit randomly sets the power transmission phase of the antennas included in the group other than N of the plurality of groups for each time slot, according to any one of claims 2 to 4.

6. The power supply system according to claim 5, wherein the position of the second power receiving device is fixed.

7. The power supply system according to claim 1, wherein the first power receiving device is movable.

8. Power supply device and A first power receiving device that receives a power transmission signal transmitted from the aforementioned power supply device. A power supply method in a power supply system including, The power supply device is An array antenna having multiple antennas capable of transmitting power, A power transmission control unit that controls the potential transmission phase of the power transmission signal transmitted from the plurality of antennas to the first power receiving device and performs power transmission control. It has, The aforementioned multiple antennas are divided into multiple groups, Each group includes a plurality of the aforementioned antennas, N (where N is an integer of 2 or more) antennas from among the plurality of groups constitute an antenna subset that transmits the power transmission signal to the first power receiving device. A power supply method in which the first power receiving device selects the top N groups with the largest received power of the power transmission signal as groups that constitute the antenna subset.

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