Electronic apparatus, control method, and control program

Abstract

To enable simultaneous wireless transmission of information and power without using a special configuration for a power reception-side device.SOLUTION: For example, an electronic apparatus includes: a plurality of antennas 11; a transmitter 13 capable of transmitting, from the plurality of antennas 11, a first radio wave with a beam directed in a first direction and a second radio wave with a beam directed in a second direction different from the first direction; and a controller 16 that controls a transmission weight of the first radio wave so that a null is directed in the second direction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present application relates to an electronic device, a control method, and a control program. [Background technology]

[0002] Patent Document 1 discloses a contactless power supply device that uses a signal obtained by combining multiple high-frequency signals with different frequencies as a power supply signal, sets the wave number of the high-frequency signal according to the amount of power to be supplied to a power receiving means, and phase-modulates the high-frequency signal to achieve simultaneous transmission of power and information. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5570343 Summary of the Invention [Problem to be solved by the invention]

[0004] To achieve simultaneous transmission of power and information, the wireless power required for power supply is much larger than the power required for communication. Therefore, when a wide bandwidth is used for power supply, as in conventional technology, there is a concern that the frequency may affect other systems using adjacent frequencies. To avoid this, it is possible to communicate information using the Orthogonal Frequency Division Multiplexing (OFDM) digital modulation method and insert the power transmission signal into unused null subcarriers in the OFDM signal. However, this requires a special configuration in the power receiving device, such as separating the power signal from the information signal, which may be disadvantageous in terms of power consumption and cost. Therefore, there was room for improvement in technology for simultaneous wireless transmission of information and power without transmitting the power supply signal over a wide bandwidth or requiring a special configuration in the power receiving device. [Means for solving the problem]

[0005] An electronic device according to one aspect includes a plurality of antennas, a transmitting unit capable of transmitting, from the plurality of antennas, a first radio wave with a beam directed in a first direction and a second radio wave with a beam directed in a second direction different from the first direction, and a control unit that controls a transmission weight for the first radio wave so that a null is directed in the second direction.

[0006] A control method according to one aspect is applied to an electronic device having a plurality of antennas and a transmitting unit capable of transmitting, from the plurality of antennas, a first radio wave with a beam directed in a first direction and a second radio wave with a beam directed in a second direction different from the first direction, and includes a step of controlling a transmission weight for the first radio wave so as to direct a null in the second direction.

[0007] A control program according to one aspect is a control program applied to an electronic device having a plurality of antennas and a transmitting unit capable of transmitting, from the plurality of antennas, a first radio wave with a beam directed in a first direction and a second radio wave with a beam directed in a second direction different from the first direction, and causes the electronic device to execute a step of controlling a transmission weight for the first radio wave so as to direct a null in the second direction. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram for explaining an overview of a wireless power transmission system that realizes simultaneous transmission of power and information using an electronic device according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating an example of the configuration of the power transmitting device according to the embodiment. [Figure 3] FIG. 3 is a diagram illustrating functional blocks of the power transmitting device according to the embodiment. [Figure 4] FIG. 4 is a diagram illustrating an example of a sequence of the system according to the embodiment. [Figure 5] FIG. 5 is a diagram illustrating another exemplary configuration of a wireless power transmission system according to an embodiment. [Figure 6] FIG. 6 is a diagram illustrating functional blocks of the power transmitting device and the OFDM signal transmitter according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Several embodiments for implementing the electronic device, control method, control program, etc. according to the present application will be described in detail with reference to the drawings. Note that the present invention is not limited by the following description. Furthermore, the components in the following description include those that can be easily imagined by a person skilled in the art, those that are substantially the same, and those that are within the so-called equivalent range. In the following description, similar components may be assigned the same reference numerals. Furthermore, duplicated descriptions may be omitted. Note that the following description of the electronic device according to the present invention also serves as a description of the control method and control program according to the present invention.

[0010] FIG. 1 is a diagram illustrating an overview of a wireless power transmission system that realizes simultaneous transmission of power and information using an electronic device according to an embodiment. The system 1 illustrated in FIG. 1 includes, for example, a wireless power transmission system capable of microwave transmission (space transmission) wireless power transmission. Wireless power transmission is a mechanism that enables power transmission without using, for example, a cable or a plug. The microwave transmission system 1 uses radio waves (microwaves) for energy transmission, and therefore uses narrowband, unmodulated waves. The system 1 can also transmit power over, for example, multiple frequency bands. In Japan, the multiple frequency bands include, for example, 920 MHz, 2.4 GHz, and 5.7 GHz. In this embodiment, the system 1 can simultaneously improve power supply efficiency appropriate for the situation and ensure safety. The system 1 can be applied to, for example, space solar power generation.

[0011] In the example shown in FIG. 1 , the system 1 includes a power transmitting device 10 and a power receiving unit 20. The power transmitting device 10 and the power receiving unit 20 communicate a communication signal 210 and a power signal 220 using, for example, spatial multiplexing technology. The spatial multiplexing technology includes, for example, space division multiple access (SDMA). SDMA is a multiple access technology that allows multiple communication entities to share the same communication path without interference. SDMA is a method of spatially dividing a transmission path to allow multiple entities to communicate simultaneously. In the system 1, the power transmitting device 10 simultaneously transmits the communication signal 210 and the power signal 220 to the power receiving unit 20 using spatial multiplexing. The system 1 directs a beam 200A including the power signal 220 toward an antenna 21A connected to a power receiving device 22 to which power is to be transmitted, and directs a beam 200B not including the power signal 220 toward an antenna 21B connected to a transceiver 25. 1, the power transmitting device 10 is an example of an electronic device. The communication signal 210 and the power signal 220 are examples of an information communication signal and a power transmission signal.

[0012] The power transmitting device 10 includes multiple antennas 11. The power transmitting device 10 can use, for example, multiple-input multiple-output (MIMO) antenna technology. In MIMO, antenna elements at each end of a communication circuit are combined to minimize errors and optimize data rates. The power transmitting device 10 is a device that transmits power wirelessly in the system 1. The power transmitting device 10 is a device that can transmit power supply radio waves to the power receiving unit 20. The power transmitting device 10 emits radio waves with a power signal 220 and a communication signal 210 at different adjacent frequencies.

[0013] The power receiving unit 20 is a powered device in the system 1 that receives power transmission radio waves from the power transmitting device 10 to obtain power. The power receiving unit 20 includes various devices such as an IoT (Internet of Things) sensor, a smartphone, a tablet terminal, a laptop personal computer, a drone, an electric vehicle, an electric bicycle, and a game console. In this embodiment, a case will be described in which the power receiving unit 20 is an IoT sensor.

[0014] The power receiving unit 20 includes, for example, antennas 21A and 21B, a power receiving device 22, a battery 23, a sensor unit 24, and a transceiver 25. The power receiving unit 20 is equipped with the antennas 21A and 21B as separate antennas, with a predetermined distance between them. The predetermined distance includes, for example, a distance at which the antennas 21A and 21B are not affected by signals that are not the target of reception, a distance according to the range of directivity control of the power transmitting device 10, etc.

[0015] The antenna 21A is electrically connected to the power receiving device 22. The antenna 21A is, for example, an antenna for receiving power. The antenna 21A emits, for example, radio waves including a specified signal and receives radio waves including a power supply signal from the power transmitting device 10. The antenna 21A supplies the received radio waves to the power receiving device 22.

[0016] The antenna 21B is electrically connected to the transceiver 25. The antenna 21B is, for example, an antenna for information communication. For example, the antenna 21B transmits sensor data including information detected by the sensor unit 24 in accordance with the control of the transceiver 25. The antenna 21B supplies a signal received from the power transmitting device 10 to the transceiver 25.

[0017] The power receiving device 22 transmits a prescribed signal determined between the power receiving device 22 and the power transmitting device 10. The prescribed signal includes, for example, a beacon signal, a pilot signal, etc. The power receiving device 22 can transmit the prescribed signal, for example, at a preset transmission cycle. The power receiving device 22 can transmit the prescribed signal by emitting radio waves including the prescribed signal. The power receiving device 22 can transmit the prescribed signal to the power transmitting device 10, for example, at a predetermined timing. The predetermined timing includes, for example, a timing after a certain time has elapsed, a specified timing, etc.

[0018] The power receiving device 22 is electrically connected to the battery 23. The power receiving device 22 includes, for example, a wireless power receiving device. The power receiving device 22 converts radio waves received by the antenna 21A into direct current and controls charging of the battery 23 using this direct current. The power receiving device 22 converts radio waves into direct current using, for example, a known rectifier circuit.

[0019] The battery 23 includes a rechargeable battery. The battery 23 includes, for example, a battery compatible with Qi (an international standard for wireless power supply). The battery 23 can supply stored power to each unit requiring power in the power receiving device 22. The battery 23 is electrically connected to the sensor unit 24 and the transceiver 25, and supplies power to the sensor unit 24, the transceiver 25, etc.

[0020] The sensor unit 24 includes a plurality of sensors. For example, the plurality of sensors include an acceleration sensor, a direction sensor, a gyro sensor, and the like. The sensor unit 24 can detect the state, changes, and the like of the object to be measured. The sensor unit 24 is electrically connected to the transceiver 25. The sensor unit 24 supplies information indicating the detection result to the transceiver 25.

[0021] The transceiver 25 transmits and receives OFDM signals using the OFDM digital modulation method. The transceiver 25 forms carrier waves (subcarriers) of multiple different frequencies within a frequency band and performs multiplexing by simultaneously transmitting and receiving these subcarriers.

[0022] The transceiver 25 includes, for example, a wireless communication device and a control device. The transceiver 25 emits, via the antenna 21B, radio waves including an OFDM signal indicating the detection result detected by the sensor unit 24. The transceiver 25 executes control of data processing, sensing data acquisition, data management, etc., based on the signal received via the antenna 21B.

[0023] An example of the functional configuration of the power receiving unit 20 according to this embodiment has been described above. Note that the above configuration described using Fig. 1 is merely an example, and the functional configuration of the power receiving unit 20 according to this embodiment is not limited to this example. The functional configuration of the power receiving unit 20 according to this embodiment can be flexibly modified according to specifications and operation.

[0024] In this embodiment, the system 1 realizes simultaneous wireless transmission of information and power by controlling the antenna directivity of multiple antennas 11 using the power transmitting device 10. For example, the center frequency of an OFDM signal is called a null subcarrier and is not used as an information communication signal. The system 1 uses a method in which a power transmission signal is inserted into the unused null subcarrier. The system 1 controls (null steering) the information communication antenna 21B of the power receiving unit 20 so that the power signal 220 is combined in antiphase. The system 1 controls (beamforming) the antenna directivity of the power transmission antenna 21A of the power receiving unit 20 so that the power signal 220 is combined in phase. The power transmitting device 10 transmits to the power receiving device 22 a signal in which the power signal 220 is superimposed near the center frequency of the communication signal 210. The power transmitting device 10 transmits to the transceiver 25 a signal in which the communication signal 210 is nulled near the center frequency of the communication signal 210. This allows the system 1 to use the transmission and reception circuits of inexpensive wireless LANs that are widely used for information communication.

[0025] In the system 1, the power transmitting device 10 transmits a signal in which the communication signal 210 and the power signal 220 are superimposed, but the power signal 220 is only combined in reverse phase at the information communication antenna 21B of the communication partner. Therefore, even if another receiving device receives the signal from the power transmitting device 10, the system 1 cannot demodulate the information, which also has the effect of concealing information and preventing eavesdropping.

[0026] Fig. 2 is a diagram illustrating an example of the configuration of a power transmitting device 10 according to an embodiment. As shown in Fig. 2, the power transmitting device 10 includes a plurality of antennas 11, a transmission signal generating unit 12, a transmitting unit 13, a receiving unit 14, a storage unit 15, and a control unit 16. The control unit 16 is electrically connected to the transmission signal generating unit 12, the transmitting unit 13, the receiving unit 14, the storage unit 15, etc. In this embodiment, the power transmitting device 10 will be described as having four plurality of antennas 11, but the number of the plurality of antennas 11 is not limited to this and may be two or more.

[0027] The multiple antennas 11 are configured to enable directivity control (beam forming) through digital signal processing. The multiple antennas 11 form an antenna array. For example, the multiple antennas 11 are configured to each emit the same radio wave and adjust their phases and power intensities to strengthen the radio wave in a specific direction and weaken it by canceling each other out in another direction. The multiple antennas 11 emit radio waves including a transmission signal 200 and receive radio waves including a signal from the power receiving device 22. The multiple antennas 11 supply the received signals to the receiving unit 14. The multiple antennas 11 have a main lobe in the direction of the beam in which the radio wave radiation is at its maximum.

[0028] The transmission signal generation unit 12 generates a power signal 220 by converting a current to be transmitted to the power receiving device 22 into a radio wave. The transmission signal generation unit 12 converts a current from a power source into a radio wave of a transmission frequency to generate a transmission signal 200. The power source includes, for example, a commercial power source, a DC power source, a battery, etc. The transmission signal generation unit 12 generates a communication signal 210 to be transmitted to the transceiver 25. The transmission signal generation unit 12 supplies the communication signal 210 and the power signal 220, which become the generated transmission signal, to the transmission unit 13.

[0029] The transmitter 13 is electrically connected to the multiple antennas 11. The transmitter 13 radiates radio waves including a communication signal 210, a power signal 220, etc. from the multiple antennas 11. The transmitter 13 applies weights corresponding to beams 200A, 200B that can be formed by the multiple antennas 11, thereby radiating the radio waves in specific directions from the multiple antennas 11. The transmitter 13 applies weights instructed by the control unit 16 to the multiple antennas 11.

[0030] The receiving unit 14 is electrically connected to the multiple antennas 11. The receiving unit 14 extracts a received signal from the radio waves received from the power receiving device 22 via the antenna 11. The received signal includes, for example, the above-mentioned specified signal transmitted from the power receiving device 22 via the antenna 21A, a communication signal transmitted from the transceiver 25 via the antenna 21B, etc. The receiving unit 14 supplies the extracted received signal, etc. to the control unit 16, etc.

[0031] The storage unit 15 can store programs and data. The storage unit 15 may include any non-transitory storage medium such as a semiconductor storage medium or a magnetic storage medium. The storage unit 15 may include a combination of a storage medium such as a memory card, an optical disk, or a magneto-optical disk, and a storage medium reader. The storage unit 15 may include a storage device used as a temporary storage area, such as RAM.

[0032] The storage unit 15 can store a control program 15A, vector data 15B, etc. The control program 15A can provide functions for implementing processes related to various operations of the power transmitting device 10. The control program 15A can provide functions related to wireless power transmission, communication control, etc. The vector data 15B includes, for example, data indicating a reception response vector, etc. The reception response vector indicates channel characteristics between transmitting and receiving antennas estimated from a received signal. The reception response vector indicates, for example, channel characteristics for the number of antennas. The reception response vector includes, for example, a vector obtained by combining the amplitude, phase, etc. of each of the multiple antennas 11. The reception response vector includes, for example, a reception response vector corresponding to power and information communication. The vector data 15B includes, for example, information indicating the reception response vectors of the power receiving device 22 and the transceiver 25 estimated based on a received signal.

[0033] The control unit 16 includes one or more arithmetic units. Examples of the arithmetic units include, but are not limited to, a central processing unit (CPU), a system-on-a-chip (SoC), a micro control unit (MCU), a field-programmable gate array (FPGA), and a coprocessor. The control unit 16 executes the control program 15A on the arithmetic units, thereby realizing processes related to various operations of the power transmitting device 10. The control unit 16 may implement at least some of the functions provided by the control program 15A using a dedicated integrated circuit (IC).

[0034] The control unit 16 executes the control program 15A to perform antenna directivity control. For example, the control unit 16 controls the transmission weight of a power signal 220 transmitted from a plurality of antennas 11 to a power receiving device 22 and a transceiver 25 that are connected via spatial multiplexing, so that a beam 200A is directed to the antenna 21A (first antenna) of the power receiving device 22 and a null is directed to the antenna 21B (second antenna) of the transceiver 25. For a communication signal 210 transmitted at a different frequency adjacent to the power signal 220, the control unit 16 controls the transmission weight so that a beam is directed to both or either the antenna 21A of the power receiving device 22 and the antenna 21B of the transceiver 25.

[0035] The control unit 16 has functional units such as a first estimation unit 16A, a second estimation unit 16B, and a generation unit 16C. The control unit 16 executes the control program 15A to realize the respective functional units such as the first estimation unit 16A, the second estimation unit 16B, and the generation unit 16C.

[0036] The first estimation unit 16A receives the frequency division multiplexed signal transmitted from the transceiver 25 and estimates the channel characteristics of the frequency components from subcarriers adjacent to unused frequency components in the band. The first estimation unit 16A estimates the reception response vector using a well-known algorithm, for example, as disclosed in Japanese Patent Application Laid-Open No. 2002-43995. The first estimation unit 16A reflects the channel characteristics for the number of antennas 11 in the vector data 15B as reception response vectors for information communication.

[0037] The second estimation unit 16B receives a specified signal transmitted from the power receiving device 22 and estimates the channel characteristics of the frequency component. The second estimation unit 16B estimates the channel characteristics of the center frequency of the specified signal. The specified signal may be an unmodulated wave or a modulated wave such as an OFDM signal. In the case of a modulated wave such as an OFDM signal, the second estimation unit 16B estimates the channel characteristics of the center frequency by, for example, interpolation. The second estimation unit 16B estimates a receiving response vector using, for example, the well-known algorithm described above. The second estimation unit 16B stores the channel characteristics for the number of antennas 11 in vector data 15B as receiving response vectors for power transmission.

[0038] The generation unit 16C generates a power transmission weight and an information communication weight from a power transmission reception response vector and a communication reception response vector based on the estimation results of the first estimation unit 16A and the second estimation unit 16B. The weights can be generated using, for example, a ZF (Zero-Forcing) algorithm or an MMSE (Minimum Mean Square Error) algorithm used in MIMO. The generation unit 16C applies the power transmission weight and the information communication weight to the power signal 220 and the communication signal 210. As a result, the transmission unit 13 multiplies the power signal 220 by the power transmission weight and the communication signal 210 by the signal weight, adds them together, and transmits them.

[0039] An example of generation of transmission weights by the generation unit 16C will be described below. The generation unit 16C sets the reception response vector of the specified signal from the power receiving device 22 to vector h1 shown in equation (1).

number

[0040] The generation unit 16C sets the reception response vector of the signal from the transceiver 25 to vector h2 shown in equation (2).

number

[0041] The generation unit 16C defines the propagation channel matrix H of the vector h1 and the vector h2 as shown in equation (3), where K is the number of antenna elements.

number

[0042] The generation unit 16C generates the transmission weights for power transmission as shown in equation (4) and the transmission weights for information communication as shown in equation (5). α1*(H*H H +σ 2 *I) -1 *z1···(4) α2*z2 (5) Here, α1 and α2 are the transmission power adjustment amounts. H is the complex conjugate transpose of the propagation channel matrix H. z1 and z2 are the complex conjugate vectors of h1 and h2. σ 2 is the noise power. I is the identity matrix.

[0043] An example of the functional configuration of the power transmitting device 10 according to this embodiment has been described above. Note that the above configuration described with reference to Fig. 2 is merely an example, and the functional configuration of the power transmitting device 10 according to this embodiment is not limited to this example. The functional configuration of the power transmitting device 10 according to this embodiment can be flexibly modified according to specifications and operation.

[0044] Fig. 3 is a diagram illustrating functional blocks of the power transmitting device 10 according to the embodiment. In the example shown in Fig. 3, the power transmitting device 10 supports dual multiplexing in which the power receiving device 22 and the transceiver 25 are connected in spatial multiplexing communication using four antennas 11.

[0045] 3, in the power transmitting device 10, signals received by the multiple antennas 11 are supplied to a reception processing unit 10A via a reception circuit 140, and adaptive array processing is used to extract the reception signal from the power receiving device 22 and the reception signal from the transceiver 25. The power transmitting device 10 supplies transmission signals for the power receiving device 22 and the transceiver 25 to a transmission processing unit 10B, and after the transmission directivity is controlled, the signals are combined and transmitted by the multiple antennas 11. The power transmitting device 10 is configured so that connections between the multiple antennas 11 and the transmission circuit 130 and the reception circuit 140 can be selectively switched by a switch SW.

[0046] In the power transmitting device 10, signals received by a plurality of antennas 11 are supplied to a reception processing unit 10A via a switch SW and a receiving circuit 140. The power transmitting device 10 supplies received signals from both or either of the power receiving device 22 and the transceiver 25 to a plurality of multipliers, and also supplies the received signals to a reception weight generation unit 16D and an estimation unit 160. The estimation unit 160 includes the first estimation unit 16A and second estimation unit 16B described above.

[0047] In the power transmitting device 10, the receiving weight generation unit 16D outputs weights for the signals received at each antenna 11 and supplies the weights to a plurality of multipliers. The receiving response vector estimation algorithm used in the estimation unit 160 may be a well-known algorithm used in MIMO or the like.

[0048] The power transmitting device 10 multiplies signals received by multiple antennas 11 by corresponding weights using multiple multipliers, and adds the results using an adder. The power transmitting device 10 outputs the array output from the adder as a received signal from the reception processing unit and supplies it to the reception weight generation unit 16D. The power transmitting device 10 supplies a known reference signal to the reception weight generation unit 16D and the estimation unit 160. The power transmitting device 10 converges the reception weight vector in real time so as to reduce the square of the error between the array output from the adder and the known reference signal. This allows the power transmitting device 10 to converge the reception directivity from a specific power receiving device 22 and transceiver 25 and extract the reception signal from the power receiving device 22 and transceiver 25.

[0049] The power transmitting device 10 calculates reception response vectors for the power receiving device 22 and the transceiver 25 based on the reception signals received by the multiple antennas 11 by the estimation unit 160 and a known reference signal, and supplies the calculated vectors to the generation unit 16C of the transmission processing unit 10B. The power transmitting device 10 generates a power transmission weight and a data communication weight from the power transmission reception response vector and the communication reception response vector. For each of the multiple antennas 11, the power transmitting device 10 multiplies the power signal 220 by the power transmission weight and multiplies the communication signal 210 by the signal weight, and transmits the sum of these transmission signals from the multiple antennas 11 via the transmission circuit 130.

[0050] The power transmitting device 10 supplies a receiving response vector consisting of components of an antenna combination corresponding to the power receiving device 22 and the transceiver 25 to the generating unit 16C, and generates a transmission weight vector based on the receiving response vector. The power transmitting device 10 multiplies the power signal 220 and the communication signal 210 by transmission weights constituting the transmission weight vector using multiple multipliers, adds these signals together using an adder, and transmits the resulting transmission signal from the multiple antennas 11 via the transmitting circuit 130.

[0051] Fig. 4 is a diagram showing an example of a sequence of the system 1 according to the embodiment. In the example shown in Fig. 4, the system 1 includes a power transmitting device 10 and a power receiving unit 20 provided in a radio wave propagation environment.

[0052] The transceiver 25 of the power receiving unit 20 transmits the OFDM signal to the power transmitting device 10 (step S11). For example, the transceiver 25 transmits the OFDM signal to the power transmitting device 10 by emitting radio waves including an OFDM signal for information communication indicating the detection result detected by the sensor unit 24 from the antenna 21B.

[0053] When the power transmitting device 10 receives the OFDM signal via the multiple antennas 11, it estimates a reception response vector for information communication (step S12). Because the center frequency of the OFDM signal is a null subcarrier, the channel characteristics estimated by the power transmitting device 10 do not include this channel characteristic. Therefore, the power transmitting device 10 estimates the channel characteristics of the center frequency from other adjacent subcarriers by interpolation or the like. The power transmitting device 10 reflects the channel characteristics for the number of antennas 11 as reception response vectors for information communication in the vector data 15B of the storage unit 15.

[0054] The power receiving device 22 of the power receiving unit 20 transmits the regulation signal to the power transmitting device 10 (step S13). For example, the power receiving device 22 transmits the regulation signal to the power transmitting device 10 by emitting radio waves including the regulation signal from the antenna 21A in accordance with the transmission period.

[0055] When the power transmitting device 10 receives the specified signal via the multiple antennas 11, it estimates a reception response vector for power transmission (step S14). If the specified signal is an unmodulated wave, the power transmitting device 10 estimates the channel characteristics of the center frequency from the specified signal, or if the specified signal is an OFDM signal, from other subcarriers adjacent to the specified signal by interpolation or the like. The power transmitting device 10 reflects the channel characteristics for the number of antennas 11 in the vector data 15B as reception response vectors for power transmission.

[0056] The power transmitting device 10 generates a transmission weight so as to direct a beam of the power transmission signal toward the power receiving device 22 and a null toward the transceiver 25 (step S15). The power transmitting device 10 generates a weight for power transmission and a weight for information communication from the reception response vector for power transmission and the reception response vector for communication in the vector data 15B. When generating a transmission weight for spatial multiplexing technology in wireless communication, the weight used at the time of reception may be copied and used as is, assuming that signals from multiple users are received simultaneously. However, in the system 1 according to the embodiment, there is no guarantee that the specified signal for power transmission and the wireless signal from the transceiver 25 are transmitted at the same time. For this reason, the power transmitting device 10 generates a weight for power transmission and a weight for information communication using the reception response vector.

[0057] The power transmitting device 10 transmits the power signal 220 and the communication signal 210 based on the generated transmission weights (step S16). The power transmitting device 10 multiplies the power signal 220 by the power transmission weight, multiplies the communication signal 210 by the signal weight, adds these together, and transmits them. As a result, the power transmitting device 10 radiates radio waves including the communication signal 210 and the power signal 220 from the multiple antennas 11 toward the power receiving device 22, and controls the directivity of the power signal 220 from the multiple antennas 11 toward the antenna 21B connected to the transceiver 25 so that the power signal 220 is synthesized in antiphase.

[0058] The power receiving device 22 charges the battery 23 based on the received power signal 220 (step S17). For example, the power receiving device 22 converts the radio waves received by the antenna 21A into a direct current, and charges the battery 23 using this direct current.

[0059] The transceiver 25 executes processing based on the received communication signal 210 (step S18). For example, the transceiver 25 executes processing such as communication control, sensing by the sensor unit 24, and data management.

[0060] In the system 1, the power transmitting device 10 does not need to direct a null to the antenna 21A connected to the power receiving device 22 for the radio waves of the communication signal 210, and communication is possible even if the reception level of the communication signal 210 is lower than that of the power signal 220, so the radio waves of the communication signal 210 do not necessarily need to direct a beam to the transceiver 25. For this reason, the power transmitting device 10 of the system 1 may prioritize the transmission weight for power transmission and generate a transmission weight for information communication so as to reduce the impact on power transmission.

[0061] The transmission weight for power transmission generally has a different weight amplitude for each antenna 11 in order to control the direction of the null, and the weight for information communication is superimposed only on the antenna 11 with a small weight amplitude. This allows the power transmitting device 10 to simultaneously transmit power and information without being affected by limitations on the instantaneous maximum output due to the performance of the transmission amplifier, even when the power transmission signal and the information communication signal are superimposed.

[0062] The power transmitting device 10 can control the transmission weight of the power signals 220 transmitted from the multiple antennas 11 to the power receiving device 22 and the transceiver 25 that are connected via spatial multiplexing, so as to direct a beam to the antenna 21A of the power receiving device 22 and a null to the antenna 21B of the transceiver 25. This allows the power transmitting device 10 to simultaneously supply power to the power receiving device 22 and communicate with the transceiver 25. As a result, the power transmitting device 10 can achieve simultaneous wireless transmission of information and power without using a special configuration in the power receiving device 22 that separates the power signals 220 and the communication signals 210.

[0063] The power transmitting device 10 can control the transmission weight of the power signals 220 transmitted from the multiple antennas 11 to the power receiving device 22 and the transceiver 25 that are spatially multiplexed connected, so as to direct a null to the antenna 21B of the transceiver 25. This allows the system 1 to use an inexpensive wireless LAN (Local Area Network) or the like as the transceiver 25, thereby simplifying the configuration of the power receiving side.

[0064] The power transmitting device 10 receives a frequency division multiplexed signal transmitted from the transceiver 25 and estimates the channel characteristics of a frequency component that is not used in the band from subcarriers adjacent to the frequency component. The power transmitting device 10 receives a specified signal transmitted from the power receiving device 22 and estimates the channel characteristics of the frequency component. The power transmitting device 10 generates a weight for power transmission and a weight for information communication from a receiving response vector for power transmission and a receiving response vector for communication based on the estimation results. As a result, the power transmitting device 10 generates a transmission weight according to the channel characteristics of the radio waves from the power receiving device 22 and the transceiver 25, and therefore, it is possible to accurately direct a null for the power signal 220 to the antenna 21B of the transceiver 25.

[0065] The power transmitting device 10 can superimpose a transmission weight for information communication on the antenna 11 when the amplitude of the transmission weight for power transmission is equal to or lower than a predetermined level. When the power signal 220 and the communication signal 210 are superimposed and transmitted, it is necessary to consider the amplitude of the transmission weight of the power signal 220, the amplitude of the transmission weight of the communication signal 210, and also the instantaneous power of the communication signal 210 because the communication signal 210 is a modulated wave. The predetermined level includes, for example, a threshold (level) for determining whether performance degradation occurs due to the characteristics of the transmitting amplifier even when the transmission weight of the communication signal 210 and the instantaneous maximum power of the communication signal 210 are taken into consideration. Even when the communication signal 210 and the power signal 220 are superimposed, the power transmitting device 10 can simultaneously transmit power and information without being affected by limitations on the instantaneous maximum output due to the performance of the transmitting amplifier.

[0066] In the above-described system 1, the power transmitting device 10 uses a reception weight when receiving an OFDM signal and a transmission weight when transmitting an OFDM signal that is common to all subcarriers, but different weights may be used for each subcarrier.

[0067] In the above-described system 1, the case where the power transmitting device 10 and the power receiving unit 20 are in a one-to-one relationship has been described, but the present invention is not limited to this. For example, the system 1 may be in a one-to-multiple relationship between the power transmitting device 10 and the power receiving unit 20.

[0068] In the above-described system 1, the power transmitting device 10 uses the same antenna 11 for both receiving the OFDM signal for information communication and transmitting power, but the present invention is not limited to this. For example, the system 1 may use a separate antenna on the power transmitting side for transmitting the OFDM signal for information communication.

[0069] Fig. 5 is a diagram illustrating another configuration example of a wireless power transmission system according to an embodiment. Fig. 6 is a diagram illustrating functional blocks of a power transmitting device 10 and an OFDM signal transmitter 30 according to an embodiment.

[0070] 5 includes a power transmitting device 10, a power receiving unit 20, and an OFDM signal transmitter 30. The power transmitting device 10 and the OFDM signal transmitter 30 are electrically connected. In the system 1A, the power transmitting device 10 radiates a power signal 220 from an antenna 11 to the power receiving unit 20. At this time, the power transmitting device 10 directs a beam 200A toward an antenna 21A connected to a power receiving device 22 to which power is to be transmitted, and simultaneously directs a null beam toward an antenna 21B connected to a transceiver 25. The OFDM signal transmitter 30 radiates a communication signal 210 from an antenna 31 and transmits the communication signal 210 to the transceiver 25 of the power receiving unit 20. In this way, the power transmitting device 10 realizes simultaneous transmission of power and information between the power transmitting device 10 and the power receiving unit 20 using the power signal 220 and the communication signal 210.

[0071] As shown in Fig. 6, in the power transmitting device 10, an estimation unit 160 including a first estimation unit 16A and a second estimation unit 16B calculates reception response vectors for the power receiving device 22 and the transceiver 25 according to received signals received by the multiple antennas 11 and a known reference signal, and supplies the calculated reception response vectors to a generation unit 16C of a transmission processing unit 10B. The power transmitting device 10 generates power transmission weights from the reception response vectors for power transmission and the reception response vectors for communication. The power transmitting device 10 transmits transmission signals obtained by multiplying a power signal 220 by the power transmission weight for each of the multiple antennas 11 via a transmission circuit 130 from the multiple antennas 11. The power transmitting device 10 transmits a communication signal 210 via an antenna 31 connected to an OFDM signal transmitter 30.

[0072] The OFDM signal transmitter 30 is electrically connected to the antenna 31 and includes an OFDM transmission unit 32. The OFDM transmission unit 32 emits radio waves including a communication signal 210 from the power transmitting device 10 from the antenna 31. The OFDM signal transmitter 30 may or may not synchronize its own signal with the signal transmission from the power transmitting device 10.

[0073] As a result, the system 1A does not need to consider the transmission weight of the communication signal 210 in the power transmitting device 10, and therefore can enable the simultaneous transmission of power and information without being affected by limitations on the instantaneous maximum output caused by the performance of the transmitting amplifier.

[0074] In spatial multiplexing technology for wireless communication, directivity is controlled so that the power signal 220 reaches only the power transmission antenna 21A and the communication signal 210 reaches only the information communication antenna 21B, but this is not limited to the present embodiment, system 1, and system 1A described above. The power transmitting device 10 controls the power signal 220 so that it does not leak into the transceiver 25, but the communication signal 210 may leak into the power receiving device 22. In other words, the spatial multiplexing technology in this embodiment is a different technology from the spatial multiplexing technology for wireless communication.

[0075] In the above-described embodiment, the system 1 and the system 1A are described as being an electronic device in which the power transmitting device 10 is an electronic device, but the present invention is not limited to this. The electronic device may be realized, for example, by a control device that controls a power supply device capable of emitting power supply radio waves, a computer built into the power supply device, or the like. Furthermore, the system 1 and the system 1A are described as being wireless power transmission systems, but the present invention is not limited to this. For example, the system 1 and the system 1A can be applied to a system that performs wireless communication in a radio wave propagation environment, or the like.

[0076] Characteristic embodiments have been described to fully and clearly disclose the technology claimed in the appended claims. However, the appended claims should not be limited to the above-described embodiments, but should be construed to embody all modifications and alternative configurations that may be conceived by those skilled in the art within the scope of the basic concepts set forth herein. Those skilled in the art can make various modifications and alterations to the contents of the present disclosure based on the present disclosure. Therefore, these modifications and alterations are within the scope of the present disclosure. For example, in each embodiment, each functional unit, each means, each step, etc. may be added to other embodiments as long as there is no logical contradiction, or may be replaced with each functional unit, each means, each step, etc. of other embodiments. Furthermore, in each embodiment, multiple functional units, each means, each step, etc. may be combined into one or divided into separate units. Furthermore, the above-described embodiments of the present disclosure are not limited to faithful implementation of each described embodiment, and may be implemented by combining each feature or omitting some features as appropriate.

[0077] [Appendix 1] A plurality of antennas; a control unit that controls transmission weights for power transmission signals transmitted from the plurality of antennas to the power transmission receiving device and the information signal transceiver so that a beam is directed to a first antenna of the power transmission receiving device and a null is directed to a second antenna of the information signal transceiver; a transmitter capable of transmitting the power transmission transmission signal using the transmission weight; In an electronic device comprising: The control unit a first estimation unit that receives a frequency division multiplexed signal transmitted from the information signal transceiver and estimates channel characteristics of the frequency component from subcarriers adjacent to a frequency component that is not used in a band; a second estimation unit that receives a specified signal transmitted from the power transmission receiving device and estimates channel characteristics of the frequency component; a generation unit that generates a power transmission weight from a power transmission reception response vector and a communication reception response vector based on the estimation results of the first estimation unit and the second estimation unit; An electronic device comprising: [Appendix 2] Electronic devices and a power receiving unit that is powered by radio waves received from the electronic device; Equipped with The electronic device includes: A plurality of antennas; a control unit that controls transmission weights for power transmission signals transmitted from the plurality of antennas to the power transmission receiving device and the information signal transceiver so that a beam is directed to a first antenna of the power transmission receiving device and a null is directed to a second antenna of the information signal transceiver; a transmitter capable of transmitting the power transmission transmission signal using the transmission weight; In an electronic device comprising: The control unit a first estimation unit that receives a frequency division multiplexed signal transmitted from the information signal transceiver and estimates channel characteristics of the frequency component from subcarriers adjacent to a frequency component that is not used in a band; a second estimation unit that receives a specified signal transmitted from the power transmission receiving device and estimates channel characteristics of the frequency component; a generation unit that generates a power transmission weight from a power transmission reception response vector and a communication reception response vector based on the estimation results of the first estimation unit and the second estimation unit; Equipped with The power receiving unit is the first antenna for receiving the power transmission signal from the electronic device; a second antenna separated by a predetermined distance from the first antenna and configured to receive the information communication signal occupying a different frequency band from the power transmission signal; A power transmission system comprising: [Appendix 3] An electronic device having a plurality of antennas, controlling transmission weights of power transmission signals transmitted from the plurality of antennas to the power transmission receiving device and the information signal transceiver so that a beam is directed to a first antenna of the power transmission receiving device and a null is directed to a second antenna of the information signal transceiver; transmitting the power transmission transmission signal to a transmitter using the transmission weight; receiving a frequency division multiplexed signal transmitted from the information signal transceiver, and estimating channel characteristics of the frequency component from subcarriers adjacent to unused frequency components in a band; receiving a specified signal transmitted from the power transmission receiving device and estimating channel characteristics of the frequency component; generating a power transmission weight from a power transmission reception response vector and a communication reception response vector based on the estimation result; A control method comprising: [Appendix 4] An electronic device having a plurality of antennas, controlling transmission weights of power transmission signals transmitted from the plurality of antennas to the power transmission receiving device and the information signal transceiver so that a beam is directed to a first antenna of the power transmission receiving device and a null is directed to a second antenna of the information signal transceiver; transmitting the power transmission transmission signal to a transmitter using the transmission weight; receiving a frequency division multiplexed signal transmitted from the information signal transceiver, and estimating channel characteristics of the frequency component from subcarriers adjacent to unused frequency components in a band; receiving a specified signal transmitted from the power transmission receiving device and estimating channel characteristics of the frequency component; generating a power transmission weight from a power transmission reception response vector and a communication reception response vector based on the estimation result; A control program that executes the above. [Explanation of symbols]

[0078] 1 System 10 Power transmission equipment 11 Antenna 12 Transmission signal generator 13 Transmitter 14 Receiving unit 15 Storage section 15A Control Program 15B Vector Data 16 Control Unit 16A 1st estimation part 16B 2nd estimation part 16C generation part 20 Power receiving unit 21A, 21B Antenna 22 Power receiving device 23 Battery 24 Sensor unit 25 Transceiver 200A, 200B beam 210 Communication Signals 220 Power Signals

Claims

1. A plurality of antennas; a transmitter capable of transmitting, from the plurality of antennas, a first radio wave whose beam is directed in a first direction and a second radio wave whose beam is directed in a second direction different from the first direction; a control unit that controls a transmission weight of the first radio wave so that a null is directed in the second direction.

2. The electronic device according to claim 1 , wherein the first radio wave and the second radio wave are radio waves of different adjacent frequencies.

3. The control unit The electronic device according to claim 1 , further comprising: a transmission weight in the transmitting unit controlled so as to direct a beam of the second radio wave in the second direction.

4. The transmission unit The electronic device according to claim 1 , wherein the first radio wave and the second radio wave are transmitted simultaneously.

5. A control method applied to an electronic device including a plurality of antennas and a transmitter capable of transmitting, from the plurality of antennas, a first radio wave with a beam directed in a first direction and a second radio wave with a beam directed in a second direction different from the first direction, the control method comprising: A control method including a step of controlling a transmission weight of the first radio wave so as to orient a null in the second direction.

6. A control program applied to an electronic device including a plurality of antennas and a transmitter capable of transmitting, from the plurality of antennas, a first radio wave with a beam directed in a first direction and a second radio wave with a beam directed in a second direction different from the first direction, The electronic device includes: a control program that executes a step of controlling a transmission weight of the first radio wave so as to direct a null in the second direction;

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