Communication device, base station, and communication system

Abstract

As a method for performing contactless power transfer to a communication device, there is a method called wireless power transfer. In order to perform wireless power supply efficiently with respect to a communication device which is a device to be supplied with power, provided is a communication device characterized by comprising: a reception unit that receives a first signal, and a second signal which is controlled in accordance with power supply efficiency of the wireless power supply and with time-series data corresponding to the power supply efficiency; a control unit that, when performing the wireless power supply using the first signal, determines the time-series data corresponding to the power supply efficiency of the wireless power supply; and a transmission unit that transmits, to a base station, a third signal including the time-series data.

Description

Communication device, base station, and communication system

[0001] The present invention relates to a communication device, a base station, and a communication system.

[0002] There is a method called wireless power supply as a contactless method for supplying power to a communication device. The wireless power supply method includes a method in which a base station transmits a wireless power supply signal to a communication device to be supplied with power, and a method in which the wireless power supply signal transmitted by the base station is transmitted to the communication device to be supplied with power via a relay device (Patent Document 1).

[0003] Patent No. 7261915

[0004] For example, when a base station and a communication device to be powered are far apart, propagation loss reduces the reception level of the signal from the base station, which can result in low power supply efficiency when using a signal from the base station. Patent Document 1, for example, describes a method in which a base station wirelessly supplies power via a relay device. However, this method requires a relay device, which increases capital investment. Therefore, it is possible to wirelessly supply power using other communication devices located near the communication device to be powered. However, the power supply efficiency varies depending on the locations of the other communication devices located near the communication device to be powered and the communication performance of the other communication devices. Therefore, in order to achieve efficient wireless power supply, it is preferable to be able to select the communication device to be used for wireless power supply.

[0005] The disclosed technology has been made in view of the above, and aims to increase the efficiency of wireless power feeding.

[0006] In one aspect, a communication device is provided, comprising: a receiving unit that receives a first signal and a second signal controlled in accordance with the power supply efficiency of wireless power supply and time series data corresponding to the power supply efficiency; a control unit that determines the time series data corresponding to the power supply efficiency of wireless power supply when wireless power supply is performed using the first signal; and a transmitting unit that transmits a third signal including the time series data to a base station.

[0007] When the communication device performs wireless power feeding, the wireless power feeding can be performed with high efficiency.

[0008] FIG. 1 is a diagram illustrating an example of a communication system according to a first embodiment. FIG. 2 is a diagram illustrating an example of a functional configuration of a base station in the communication system according to the first embodiment. FIG. 3 is a diagram illustrating an example of a functional configuration of a communication device in the communication system according to the first embodiment. FIG. 4 is a diagram illustrating an example of a functional configuration of a communication device in the communication system according to the first embodiment. FIG. 5 is a diagram illustrating an example of a processing sequence of wireless power feeding in the first embodiment. FIG. 6 is a diagram illustrating an example of a time division pattern configuration related to communication of the communication device according to the first embodiment. FIG. 7 is a diagram illustrating an example of a communication system according to a second embodiment. FIG. 8 is a diagram illustrating an example of a processing sequence of wireless power feeding in the second embodiment. FIG. 9 is a diagram illustrating an example of a processing sequence of wireless power feeding in the third embodiment. FIG. 10 is a diagram illustrating an example of a hardware configuration of a base station in the communication system. FIG. 11 is a diagram illustrating an example of a hardware configuration of a communication device in the communication system. FIG. 12 is a diagram illustrating an example of a hardware configuration of a communication device in the communication system.

[0009] The present embodiment will be described in detail below with reference to the drawings. The problems and embodiments in this specification are merely examples and do not limit the scope of the rights of the present application. In particular, even if the expressions used are different, the technology of the present application can be applied as long as they are technically equivalent, and do not limit the scope of the rights. Furthermore, each embodiment can be combined as appropriate within the scope of not causing any contradiction in the processing content.

[0010] Furthermore, the terms used and technical content described in this specification may be appropriately derived from the terms and technical content described in specifications and contributions as standards related to communications, such as 3GPP (registered trademark).

[0011] Hereinafter, embodiments of a communication device, a base station, and a communication system disclosed in the present application will be described in detail with reference to the accompanying drawings. Note that the disclosed technology is not limited to the following embodiments. First Embodiment

[0012] FIG. 1 shows an example of a communication system 1 according to the first embodiment. The communication system 1 includes a base station 100, a communication device 200A, a communication device 200B, a communication device 200C, and a communication device 300. The base station 100 forms a cell C10. When the communication device 200A, the communication device 200B, and the communication device 200C are not to be distinguished from each other, they may be simply referred to as the communication device 200. Although the communication system 1 shown in FIG. 1 includes three communication devices 200, this is not limiting and any number of communication devices may be used. The communication device 200 is an example of another communication device. This also applies to the following embodiments.

[0013] The base station 100 may be, for example, a small radio base station such as a macro radio base station or a pico radio base station (including a micro radio base station, a femto radio base station, etc.), or may be a radio base station of various scales, and may be referred to as a radio communication device, a communication device, a transmitting device, etc. The communication device 200 may be, for example, a radio terminal such as a mobile phone, a smartphone, a PDA (Personal Digital Assistant), a personal computer, a vehicle, an IoT (Internet of Things) device, or any of various devices or equipment (sensor devices, etc.) having a radio communication function, and may be referred to as a radio communication device, a receiving device, a mobile station, etc.

[0014] The base station 100 is also connected to a network device (higher-level device) such as a core network (not shown) via a wired or wireless connection.

[0015] The base station 100 may have a wireless communication function for performing wireless communication with the communication device 200 and the communication device 300, and a digital signal processing and control function, which are separated into separate devices. In this case, the device having the wireless communication function may be called an RRH (Remote Radio Head), and the device having the digital signal processing and control function may be called a BBU (Base Band Unit). The RRHs are installed extending from the BBU, and they may be connected by wire or wirelessly via optical fiber or the like. Instead of the RRHs and BBUs described above, the base station 100 may be separated into, for example, a Central Unit (CU), a Distributed Unit (DU), and a Radio Unit (RU). The DU includes, for example, a MAC (Media Access Control) layer function. The DU may also have the functionality of, for example, an RLC (Radio Link Control) layer. The RU includes at least an RF wireless circuit. The DU and RU may also be integrated into one unit.

[0016] On the other hand, the communication device 200 and the communication device 300 communicate with the base station 100 via wireless communication.

[0017] Next, the base station 100 will be described. Fig. 2 is an example of a functional configuration diagram of the base station 100 in the communication system 1 of the first embodiment. As shown in Fig. 2, the base station 100 includes a wireless communication unit 110, a control unit 120, a storage unit 130, and a communication unit 140. These components are connected to each other so as to enable input and output of signals and data in one direction or two directions. The wireless communication unit 110 can be described as being divided into a transmission unit 111 and a reception unit 112.

[0018] The transmitter 111 transmits downstream signals, such as a random access procedure signal, a downstream data signal, a downstream control signal, etc., to the communication device 200 and the communication device 300 .

[0019] The receiving unit 112 can receive upstream signals transmitted from the communication device 200 and the communication device 300, such as a random access procedure signal, an upstream data signal, an upstream control signal, and the like.

[0020] The communication unit 140 also connects to and communicates with network devices (for example, higher-level devices, other communication devices) via wired or wireless connections.

[0021] The control unit 120 controls the base station 100. Specifically, the control unit 120 can control signal processing of signals received by the receiving unit 112, creation of transmission blocks (TBs), mapping of the transmission blocks to radio resources, and the like.

[0022] The storage unit 130 can store, for example, information related to a downlink data signal and wireless power feeding. The information related to wireless power feeding is, for example, information related to the power feeding efficiency of wireless power feeding performed by the communication device 300.

[0023] Next, the communication device 200 will be described. Fig. 3 is an example of a functional configuration diagram of the communication device 200 in the communication system 1 of the first embodiment. As shown in Fig. 3, the communication device 200 includes a communication unit 210, a control unit 220, and a storage unit 230. These components are connected to each other so as to enable input and output of signals and data in one direction or two directions. The communication unit 210 can be described as being divided into a transmission unit 211 and a reception unit 212.

[0024] The transmitter 211 transmits, for example, data signals and control signals by wireless communication via an antenna. The antenna may be shared with the receiver 212. The transmitter 211 transmits, for example, upstream signals such as a random access procedure signal, an upstream data signal, and an upstream control signal.

[0025] The receiving unit 212 receives downlink signals, such as a random access procedure signal, a downlink data signal, a downlink control signal, etc., transmitted from the base station 100. The received signals may also include signals such as a reference signal (RS) used for channel estimation and demodulation.

[0026] The control unit 220 controls the communication device 200. Specifically, the control unit 220 can control signal processing of signals transmitted from the base station 100 and received by the receiving unit 212, creation of transmission blocks (TBs), mapping of the transmission blocks to radio resources, and the like.

[0027] The storage unit 230 can store, for example, uplink data signals, and can also store configuration information (or setting information) related to wireless communication transmitted from the base station 100.

[0028] Next, the communication device 300 will be described. Fig. 4 is an example of a functional configuration diagram of the communication device 300 in the communication system 1 of the first embodiment. As shown in Fig. 4, the communication device 300 includes a communication unit 310, a control unit 320, a storage unit 330, and a wireless power supply unit 340. These components are connected to each other so as to enable unidirectional or bidirectional input and output of signals and data. Note that the communication unit 310 can be described as being divided into a transmission unit 311 and a reception unit 312.

[0029] The transmitter 311 transmits, for example, data signals and control signals by wireless communication via an antenna. The antenna may be shared with the receiver 312. The transmitter 311 transmits, for example, upstream signals such as a random access procedure signal, an upstream data signal, and an upstream control signal.

[0030] The receiving unit 312 receives downlink signals, such as a random access procedure signal, a downlink data signal, and a downlink control signal, transmitted from the base station 100. The receiving unit 312 also receives, for example, a data signal transmitted from the communication device 200 to the base station 100 as a signal for wireless power feeding. The received signal may also include, for example, a signal such as an RS (Reference Signal) used for channel estimation and demodulation.

[0031] The control unit 320 controls the communication device 300. Specifically, the control unit 320 can control signal processing of signals transmitted from the base station 100 and received by the receiving unit 312, creation of transmission blocks (TBs), mapping of the transmission blocks to radio resources, and the like.

[0032] The storage unit 330 can store, for example, uplink data signals. The storage unit 330 can also store configuration information (or setting information) related to wireless communication transmitted from the base station 100. The storage unit 330 can also store information related to the efficiency of wireless power feeding. Note that the information related to the efficiency of wireless power feeding is, for example, time-series data corresponding to the calculated efficiency of wireless power feeding and the measurement times of the efficiencies of wireless power feeding corresponding to each of the efficiencies of wireless power feeding.

[0033] The wireless power supply unit 340 receives, for example, a signal transmitted from the communication device 200 to the base station 100 as a signal for wireless power supply via the receiving unit 312, converts the signal into, for example, DC power, and supplies the power.

[0034] Next, a method for wireless power feeding by the communication device 300 using a signal transmitted from the communication device 200 to the base station 100 will be described with reference to Fig. 5 and Fig. 6. Fig. 5 shows an example of a sequence for wireless power feeding in the first embodiment.

[0035] First, the transmitter 111 of the base station 100 transmits to each of the communication devices 200 and 300 a signal including information for configuring time division into a period during which the communication device 200 or 300, which is the transmission target, performs data communication and a period during which no data communication is performed (e.g., a period during which wireless power is supplied) (step S50). Using the information included in the signal transmitted in step S50, the base station 100 can configure the time division pattern shown in FIG. 6 for the communication devices 200 and 300. This signal including information for configuring time division is an example of a sixth signal. FIG. 6 illustrates an example of a time division pattern configuration for each of the communication devices 200 and 300. In FIG. 6, communication ON indicates a period during which data communication is performed, and communication OFF indicates a period during which no data communication is performed. Also, in FIG. 6, each of the intervals T1 to T8 is configured, for example, by one slot or one subframe. 6, the control unit 120 of the base station 100 sets the communication periods for the communication device 200 and the communication device 300 so that the periods do not overlap. Also, the control unit 120 of the base station 100 may set the communication periods for the communication device 200 to T8 so that the periods are equal to each other. Note that the communication devices 200 to be the transmission targets may be, for example, only communication devices 200 located within a predetermined range from the communication device 300 (for example, within a range where the communication device 300 can receive a signal transmitted from the communication device 200 to the base station 100 as a wireless power supply signal).

[0036] Next, the control unit 220 of the communication device 200 and the control unit 320 of the communication device 300 receive from the base station 100 a signal including information for time division into communication periods and non-communication periods, and set the communication periods and non-communication periods according to the information (step S51). Note that the information for time division only needs to include, for example, a time division pattern configuration corresponding to each of the communication devices 200 and 300 that are the transmission targets, and does not need to include the time division pattern configurations of all of the communication devices 200 and 300 that are the transmission targets. Furthermore, the control unit 320 of the communication device 300 sets, for example, the wireless power supply unit 340 of the communication device 300 to be able to wirelessly supply power during the non-communication periods (step S51).

[0037] Next, the transmitter 211 of the communication device 200 transmits a data signal to the base station 100 during the communication period set by the control unit 220 of the communication device 200 (step S52). Note that this data signal is an example of a first signal.

[0038] Furthermore, the receiving unit 312 of the communication device 300 receives the data signal transmitted by the communication device 200 to the base station 100 (the data signal transmitted by the communication device 200 in step S52) as a signal for wireless power feeding, and the wireless power feeding unit 340 of the communication device 300 converts the power of the received data signal into, for example, DC power and wirelessly feeds power (step S53). For example, the wireless power feeding unit 340 of the communication device 300 receives the data signal transmitted by the communication device 200B in section T2 of FIG. 6 as a wireless power feeding signal and wirelessly feeds power. Furthermore, the control unit 320 of the communication device 300 calculates the efficiency of wireless power feeding using the received signal for wireless power feeding (e.g., the efficiency of conversion to DC power) for each predetermined time period (e.g., the section in which the communication device 200 performs data communication), and stores the calculated efficiency in the storage unit 330 of the communication device 300 together with time-series data corresponding to the measurement time (step S54). In measuring the efficiency of wireless power transfer, for example, the efficiency of wireless power transfer may be averaged or quantized at each measurement interval, and used as the efficiency of wireless power transfer at that time. Furthermore, for example, a timestamp may be added when the efficiency of wireless power transfer is calculated, and the timestamp may be used as time-series data for the efficiency of the wireless power transfer. Furthermore, the power transfer efficiency value may be set such that the efficiency of the wireless power transfer with the highest value is set to 1, and the efficiency values ​​of the other wireless power transfers are expressed as relative values.

[0039] Next, the transmitter 311 of the communication device 300 transmits to the base station 100, during the data communication period set by the controller 320 of the communication device 300, a signal including data on the measured efficiency of wireless power feeding and time-series data corresponding to each of the measured efficiencies of wireless power feeding (step S55). Note that, for example, the data on the efficiency of wireless power feeding to be transmitted to the base station 100 may be data on the efficiency of wireless power feeding within a predetermined range (for example, a relative value of 0.5 or more with respect to the maximum efficiency, or only the highest value, etc.). Note that the signals transmitted in step S55 are examples of the third signal and the fifth signal.

[0040] The control unit 120 of the base station 100 selects a communication device 200 that will have high efficiency of wireless power feeding to the communication device 300, based on the data on the efficiency of wireless power feeding received from the communication device 300, the time-series data corresponding to each of the efficiencies of wireless power feeding, and the set data on the period during which data communication is performed for the communication device 200 (step S56). Note that the control unit 120 of the base station 100 can associate the data on the efficiency of wireless power feeding with each of the communication devices 200, based on the time-series data and the set data on the period during which data communication is performed for the communication device 200.

[0041] Furthermore, a method for selecting a communication device 200 with high wireless power feeding efficiency is, for example, to select a communication device 200 with the highest wireless power feeding efficiency value. Furthermore, the control unit 120 of the base station 100 may select a communication device 200 with high wireless power feeding efficiency by taking into account, in addition to the data on the efficiency of wireless power feeding, for example, the remaining battery capacity of each communication device 200 (e.g., whether the remaining battery capacity is high) and whether it is possible to adjust the transmission power when transmitting a data signal (e.g., increase the transmission power).

[0042] For the sake of explanation, the following processing will be described assuming that the base station 100 has selected the communication device 200A from the communication devices 200A, 200B, and 200C. Note that the base station 100 is not limited to selecting the communication device 200A, and may select another communication device 200.

[0043] Next, the control unit 120 of the base station 100 determines setting information for controlling the transmission parameters of the data signal transmitted by the selected communication device 200A to the base station 100 so as to increase the efficiency of wireless power supply to the communication device 300 (step S56). Note that the transmission parameters include, for example, the transmission power and transmission timing of the data signal, the waveform of the data signal, etc.

[0044] The transmitter 111 of the base station 100 transmits to the target communication device 200A a signal including setting information for the parameters of the data signal that the communication device 200A transmits to the base station 100 (step S57).

[0045] The transmitter 211 of the communication device 200A transmits a data signal to the base station 100 based on the setting information of the parameters of the received data signal (step S58). The data signal transmitted in step S58 is an example of the second signal and the fourth signal. The base station 100 may transmit a signal including information about the timing at which the communication device 200A transmits the data signal to the base station 100 to the communication device 300, for example, in the section from after step S56 to before step S58, and the communication device 300 may be configured to perform wireless power feeding only at the timing at which the communication device 200A transmits the data signal (or in a predetermined section including the timing at which the communication device 200A transmits the data signal).

[0046] The receiving unit 312 of the communication device 300 receives the data signal transmitted by the communication device 200A (the data signal transmitted by the communication device 200A in step S58) as a wireless power supply signal, and the wireless power supply unit 340 of the communication device 300 converts the received wireless power supply signal into, for example, DC power and supplies power (step S59).

[0047] Through the series of processes from step S50 to step S59, the communication device 300 transmits to the base station 100 a signal including data on the efficiency of wireless power supply and time-series data corresponding to each of the efficiencies of wireless power supply, and wireless power supply is performed using a signal from the communication device 200 selected by the base station 100, thereby enabling wireless power supply with high power supply efficiency.

[0048] This series of operations may be repeated, for example, at predetermined intervals. In this case, the series of operations can be repeatedly executed by performing the same processes as steps S53 to S59 on the data signal received by the communication device 300 for wireless power supply in step S59. Furthermore, when repeatedly performing the processes, the control unit 120 of the base station 100 may transmit a signal including information on time division between communication periods and non-communication periods, with the number of communication devices 200 as transmission targets being different each time. For example, the control unit 120 may limit the transmission targets to communication devices 200 whose previous wireless power supply efficiency value is equal to or greater than a certain value (e.g., a relative value equal to or greater than 0.5). Furthermore, for example, communication devices 200 that were not included in the previous process may be added as transmission targets.

[0049] As described above, the base station 100 receives signals including data on the efficiency of wireless power feeding and time-series data corresponding to each of the efficiencies of wireless power feeding from the communication devices 300, and determines the communication devices 200 to be used for wireless power feeding. Then, the communication devices 300 perform wireless power feeding using signals transmitted from the communication devices 200 determined by the base station 100. In this way, it is possible to increase the efficiency of wireless power feeding of the communication devices 300. Note that the base station 100 may control the determined communication devices 200 so as to increase the efficiency of wireless power feeding of the communication devices 300. Embodiment 2

[0050] In the first embodiment, an example has been described in which the base station 100 receives, from the communication device 300, a signal including data on the efficiency of wireless power feeding and time-series data corresponding to each of the efficiencies of wireless power feeding, and determines the communication device 200 to which wireless power is to be fed to the communication device 300. In the second embodiment, a case will be described in which the base station 100A and the base station 100B are configured to efficiently feed wireless power to the communication device 300. Note that in the second embodiment, the base station 100, the communication device 200, and the communication device 300 are the same as in the first embodiment, and therefore description thereof will be omitted. Furthermore, in the second embodiment, description of the same parts of the processing procedure of the wireless power feeding method performed by the base station 100 to the communication device 200 and the communication device 300 as in the first embodiment will be omitted.

[0051] 7 is an example of a communication system 2 according to the second embodiment. The communication system 2 includes a base station 100A, a base station 100B, a communication device 200, and a communication device 300. The base station 100A forms a cell C10A, and the base station 100B forms a cell C10B. When the base station 100A and the base station 100B are not distinguished from each other, they can be simply referred to as the base station 100, and their functions are the same as those of the base station 100 according to the first embodiment. The base station 100A and the base station 100B are connected by wire or wirelessly, and can communicate with each other.

[0052] The processing flow of the wireless communication system in the second embodiment will be described with reference to Fig. 8. Fig. 8 shows an example of a sequence of wireless power feeding in the second embodiment. In Fig. 8, the same parts as those in Fig. 5 are given the same reference numerals and will not be described again.

[0053] First, the transmitter 111 of the base station 100 transmits, to each of the communication devices 200 and 300, a signal including information for setting the communication device 200 or 300 to be the transmission target to perform time division into a period in which the communication device 200 or 300 performs data communication and a period in which the communication device 200 or 300 does not perform data communication (steps S50 and S81). This signal including information for setting the time division is an example of a sixth signal. The controller 120 of the base station 100 may, for example, set the communication periods for the communication devices 200 and 300 so that the periods do not overlap. Alternatively, the controller 120 of the base station 100 may, for example, set the communication periods for the communication devices 200 and 300 so that the communication periods are the same. The communication devices 200 to be the transmission target may, for example, only be communication devices 200 located within a predetermined range from the communication device 300 (e.g., within a range in which the communication device 300 can receive a signal transmitted from the communication device 200 to the base station 100 as a wireless power supply signal).

[0054] Note that base station 100A targets communication devices 200A and 300 for transmission, and base station 100B targets communication device 200B for transmission. When setting a period for communication, for example, one of base stations 100 (for example, base station 100A having communication device 300 in its cell) may set a period for communication between communication device 200 and communication device 300 that are targets for transmission from base station 100. In this case, for example, base station 100A transmits a signal including settings corresponding to communication device 200 included in the cell of base station 100B to base station 100B (step S80), and base station 100B transmits to the target communication device 200 in accordance with the signal (step S81).

[0055] Next, the control unit 220 of the communication device 200 and the control unit 320 of the communication device 300 receive from the base station 100 a signal including information for time division into communication periods and non-communication periods, and set the communication periods and non-communication periods according to the information (step S51). Also, the wireless power supply unit 340 of the communication device 300 sets the wireless power supply unit 340 so that wireless power supply can be performed during the non-communication periods, for example (step S51).

[0056] Next, the transmitter 211 of the communication device 200 transmits a data signal to the corresponding base station 100 during the communication period set by the control unit 220 of the communication device 200 (step S52). The data signal transmitted in step S52 is an example of a first signal.

[0057] Furthermore, the receiving unit 312 of the communication device 300 receives the data signal transmitted by the communication device 200 to the base station 100 (the data signal transmitted by the communication device 200 in step S52) as a signal for wireless power feeding, and the wireless power feeding unit 340 of the communication device 300 converts the power of the received data signal into, for example, DC power to wirelessly feed power (step S53). Furthermore, as in the first embodiment, the control unit 320 of the communication device 300 calculates the efficiency of wireless power feeding using the received signal for wireless power feeding (for example, the efficiency of conversion to DC power) for each predetermined time period (for example, the period during which the communication device 200 performs data communication), associates the calculated efficiency with time-series data corresponding to the measurement time, and stores the calculated efficiency in the storage unit 330 of the communication device 300 (step S54).

[0058] Next, during the period for performing data communication set by the control unit 320 of the communication device 300, the transmission unit 311 of the communication device 300 transmits, to the base station 100A, signals including data on the measured efficiency of wireless power feeding and time-series data corresponding to each of the measured efficiencies of wireless power feeding, as in the first embodiment (step S55). Note that the signals transmitted in step S55 are examples of the third signal and the fifth signal.

[0059] The control unit 120 of the base station 100A selects a communication device 200 that will increase the efficiency of wireless power feeding to the communication device 300, based on the data on the efficiency of wireless power feeding received from the communication device 300, the time-series data corresponding to each of the wireless power feeding efficiencies, and the data on the set period for performing data communication for the communication device 200 (step S56). Note that the control unit 120 of the base station 100A can associate the data on the efficiency of wireless power feeding with each of the communication devices 200, based on the time-series data and the data on the set period for performing data communication for the communication device 200. Note that the method of selecting a communication device 200 that can increase the efficiency of wireless power feeding is the same as in the first embodiment.

[0060] For the sake of explanation, the following processing will be described on the assumption that the base station 100A has selected the communication device 200B from the communication devices 200A and 200B. When the base station 100A selects the communication device 200A, the communication device 300 can perform wireless power feeding with high power feeding efficiency by performing processing similar to steps S57 to S59 (see FIG. 5) in the first embodiment, although this is not shown in FIG. 8.

[0061] Next, the control unit 120 of the base station 100A determines setting information for controlling transmission parameters of a data signal transmitted by the selected communication device 200 to the base station 100B so as to increase the efficiency of wireless power supply to the communication device 300 (step S56). The transmission parameters include, for example, the transmission power, transmission timing, and waveform of the data signal. The base station 100A may only select the communication device 200, and the transmission parameters may be set by the base station 100B.

[0062] The transmitter 111 of the base station 100A transmits a signal including information instructing the base station 100B that has the communication device 200B within its cell to transmit a signal including parameter setting information (step S82), and transmits the signal including the parameter setting information to the communication device 200B selected by the received base station 100B (step S83).

[0063] The transmitter 212 of the communication device 200B transmits a data signal to the base station 100B based on the setting information of the parameters of the received data signal (step S58). Note that the data signal transmitted in step S58 is an example of the second signal and the fourth signal.

[0064] The receiving unit 312 of the communication device 300 receives the data signal transmitted by the communication device 200B (the data signal transmitted by the communication device 200B in step S58) as a wireless power supply signal, and the wireless power supply unit 340 of the communication device 300 converts the received wireless power supply signal into, for example, DC power and supplies power (step S59).

[0065] As described above, in the second embodiment, the plurality of base stations 100 receive signals including data on the efficiency of wireless power feeding and time-series data corresponding to each of the efficiencies of wireless power feeding from the communication devices 300, and determine the communication devices 200 to be used for wireless power feeding. Then, the communication devices 300 perform wireless power feeding using the signals transmitted from the communication devices 200 determined by the base stations 100. In this manner, it is possible to increase the efficiency of wireless power feeding of the communication devices 300. Note that the base station 100 may control the determined communication devices 200 so as to increase the efficiency of wireless power feeding of the communication devices 300. Embodiment 3

[0066] In the first embodiment, an example has been described in which the base station 100 receives, from the communication device 300, a signal including data on the efficiency of wireless power feeding and time-series data corresponding to each of the efficiencies of wireless power feeding, and determines a communication device 200 to wirelessly feed power to the communication device 300. In the second embodiment, an example has been described in which the base station 100 receives, from the communication device 300, a signal including data on the efficiency of wireless power feeding and time-series data corresponding to each of the efficiencies of wireless power feeding, and performs processing to control the communication device 200 so that the communication device 300 can efficiently feed wireless power, in combination with a set period in which the communication device 200 will communicate. In the third embodiment, a case will be described in which the base station 100 performs processing to control the multiple communication devices 200 so that the communication device 300 can efficiently feed wireless power. In the third embodiment, the communication system 1, the base station 100, the communication device 200, and the communication device 300 are the same as in the first embodiment, and therefore description thereof will be omitted. In the third embodiment, the same parts of the processing procedure of the wireless power feeding method that the base station 100 performs on the communication device 200 and the communication device 300 as those in the first embodiment will not be described.

[0067] The processing flow of the wireless communication system according to the third embodiment will be described with reference to Fig. 9. Fig. 9 shows an example of a sequence of wireless power feeding according to the third embodiment. In Fig. 9, the same parts as those in Fig. 5 are given the same reference numerals and will not be described again.

[0068] The control unit 120 of the base station 100 selects a plurality of communication devices 200 that can maximize the efficiency of wireless power feeding to the communication device 300, based on the data on the efficiency of wireless power feeding received from the communication device 300, the time-series data corresponding to each of the efficiencies of wireless power feeding, and the data on the set period for performing data communication for the communication device 200 (step S90). Note that when selecting a plurality of communication devices 200, the number of communication devices to be selected may be any number equal to or greater than two.

[0069] Next, the control unit 120 of the base station 100 determines setting information for controlling transmission parameters of data signals transmitted to the base station 100 by the selected communication devices 200 so as to increase the efficiency of wireless power supply to the communication devices 300 (step S90). The transmission parameters include, for example, the transmission power and transmission timing of the data signals, and the waveform of the data signals.

[0070] The transmitter 111 of the base station 100 transmits to the target communication device 200 a signal including setting information for parameters of a data signal that the determined communication device 200 will transmit to the base station 100 (step S91).

[0071] The transmitter 211 of the communication device 200 transmits a data signal to the base station 100 based on the setting information of the parameters of the received data signal (step S92). Note that the data signal transmitted in step S92 is an example of the second signal and the fourth signal.

[0072] The receiving unit 312 of the communication device 300 receives the data signal transmitted by the communication device 200 (the data signal transmitted by the communication device 200 in step S93) as a wireless power supply signal, and the wireless power supply unit 340 of the communication device 300 converts the received wireless power supply signal into, for example, DC power and supplies power (step S93). As a result, for example, by the base station 100 controlling the communication devices 300 to simultaneously receive data signals received as wireless power supply signals by a plurality of communication devices 200, the wireless power supply signal can be amplified when received, thereby improving the efficiency of wireless power supply.

[0073] As described above, the base station 100 receives signals including data on the efficiency of wireless power feeding and time-series data corresponding to each efficiency of wireless power feeding from the communication device 300, and determines a plurality of communication devices 200 to use for wireless power feeding. Then, the communication device 300 performs wireless power feeding using signals transmitted from the plurality of communication devices 200 determined by the base station 100. In this way, the wireless power feeding efficiency of the communication device 300 can be increased.

[0074] It is also possible to appropriately combine and implement embodiment 2 and embodiment 3. For example, it is conceivable that a certain base station 100 selects a plurality of communication devices 200 (including communication devices 200 outside its cell) and transmits to another base station 100 a signal including information instructing the other base station 100 to transmit a signal including transmission parameter setting information to a communication device 200 present in the cell of the other base station 100. As described above, it is also possible for a plurality of base stations 100 to control a plurality of communication devices 200. Hardware configuration of each device in each embodiment

[0075] The hardware configuration of each device in the communication system 1 of each embodiment will be described with reference to FIGS.

[0076] Fig. 10 is a diagram showing an example of the hardware configuration of base station 100. As shown in Fig. 10, base station 100 has, as hardware components, for example, an RF (Radio Frequency) circuit 420 equipped with an antenna 410, a CPU (Central Processing Unit) 430, a DSP (Digital Signal Processor) 440, a memory 450, and a network IF (Interface) 460. The CPU is connected via a bus so as to enable input and output of various signals and data signals. The memory 450 includes at least one of a RAM (Random Access Memory) such as an SDRAM (Synchronous Dynamic Random Access Memory), a ROM (Read Only Memory), and a flash memory, and stores programs, control information, and data signals.

[0077] The correspondence between the functional configuration of the base station 100 shown in Fig. 2 and the hardware configuration of the base station 100 shown in Fig. 10 will be described. The transmitter 111, receiver 112 (or wireless communication unit 110), and communication unit 140 are realized by, for example, an RF circuit 420, or an antenna 410 and an RF circuit 420. The control unit 120 is realized by, for example, a CPU 430, a DSP 440, a memory 450, a digital electronic circuit (not shown), etc. Examples of digital electronic circuits include an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), and an LSI (Large Scale Integration). The storage unit 130 is realized by, for example, the memory 450. The communication unit 110 and the communication unit are realized by the network IF 460, for example.

[0078] It should be noted that base station 100 can generate a plurality of data signals to be transmitted in a plurality of subbands, and the filters for generating these signals may be configured independently for each subband.

[0079] Fig. 11 is a diagram showing an example of the hardware configuration of communication device 200. As shown in Fig. 11, communication device 200 has, as hardware components, an RF circuit 520 including an antenna 510, a CPU 530, and a memory 540. Communication device 200 may further have a display device such as an LCD (Liquid Crystal Display) connected to CPU 530. Memory 540 includes at least one of a RAM such as an SDRAM, a ROM, and a flash memory, and stores programs, control information, and data signals.

[0080] The correspondence between the functional configuration of the communication device 200 shown in Fig. 3 and the hardware configuration of the communication device 200 shown in Fig. 11 will be described. The transmitter 211 and receiver 212 (or communication unit 210) are realized by, for example, an RF circuit 520, or an antenna 510 and an RF circuit 520. The control unit 220 is realized by, for example, a CPU 530, a memory 540, a digital electronic circuit (not shown), etc. Examples of the digital electronic circuit include an ASIC, an FPGA, and an LSI. The storage unit 230 is realized by, for example, the memory 540.

[0081] 12 is a diagram showing an example of the hardware configuration of communication device 300. As shown in FIG. 12, communication device 300 has, as hardware components, an RF circuit 620 including an antenna 610, a CPU 630, and a memory 640. Communication device 300 may further have a display device such as an LCD (Liquid Crystal Display) connected to CPU 630. Memory 640 includes at least one of a RAM such as an SDRAM, a ROM, and a flash memory, and stores programs, control information, and data signals.

[0082] The correspondence between the functional configuration of the communication device 200 shown in Fig. 3 and the hardware configuration of the communication device 200 shown in Fig. 12 will be described. The transmitter 311 and receiver 312 (or the communication unit 210), and the wireless power supply unit 340 are realized, for example, by an RF circuit 620, or an antenna 610 and an RF circuit 620. The control unit 320 is realized, for example, by a CPU 630, a memory 640, a digital electronic circuit (not shown), etc. Examples of the digital electronic circuit include an ASIC, an FPGA, and an LSI. The storage unit 330 is realized, for example, by the memory 640. Symbol explanation

[0083] 1 2 Communication system 100 100A 100B Base station 110 Wireless communication unit 111 Transmitter 112 Receiver 120 Control unit 130 Memory unit 140 Communication unit C10 C10A C10B Cell 200 200A 200B 200C 300 Communication device 210 Communication unit 211 Transmitter 212 Receiver 220 Control unit 230 Memory unit 310 Communication unit 311 Transmitter 312 Receiver 320 Control unit 330 Memory unit 340 Wireless power supply unit 410 Antenna 420 RF circuit 430 CPU 440 DSP 450 Memory 460 Network IF 510 Antenna 520 RF circuit 530 CPU 540 Memory 610 Antenna 620 RF circuit 630 CPU 640 Memory

Claims

1. A communication device comprising: a receiver that receives a first signal, a power supply efficiency of a first wireless power supply, and a second signal controlled in accordance with first time series data corresponding to the power supply efficiency of the first wireless power supply; a controller that determines the first time series data corresponding to the power supply efficiency of the first wireless power supply when wireless power is supplied using the first signal; and a transmitter that transmits a third signal including the first time series data to a base station.

2. The communication device according to claim 1, wherein the receiving unit receives an uplink signal transmitted from another communication device to a base station as the first signal used for wireless power supply.

3. The communication device according to claim 1, characterized in that the receiving unit receives an uplink signal controlled in accordance with the power supply efficiency of the first wireless power supply and the first time series data, which is transmitted to a base station by another communication device, as the second signal to be used for wireless power supply.

4. The communication device according to claim 1, wherein the receiving unit receives a fourth signal controlled in accordance with a second wireless power supply efficiency and second time series data corresponding to the second wireless power supply efficiency; the control unit, when wireless power supply is performed using the second signal, determines the second time series data corresponding to the second wireless power supply efficiency; and the transmitting unit transmits a fifth signal including the second time series data to a base station.

5. The communication device according to claim 1, wherein the power supply efficiency of the first wireless power supply is the efficiency of converting the first signal into DC power.

6. The communication device according to claim 1, wherein the first time-series data uses a timestamp when the power supply efficiency of the first wireless power supply is determined.

7. The communication device according to claim 1, wherein the receiving unit receives a sixth signal including information regarding the timing of transmitting a signal from the communication device to a base station, and the transmitting unit transmits the third signal to the base station at a timing based on the sixth signal.

8. A base station comprising: a receiving unit that receives a first signal including time series data according to the power supply efficiency of wireless power supply from a first communication device; a control unit that selects a second communication device according to the time series data; and a transmitting unit that transmits a third signal to the second communication device.

9. The base station according to claim 8, wherein the transmitting unit transmits a signal including information regarding the timing of transmitting a signal to the base station to a plurality of communication devices including the first communication device and the second communication device.

10. The base station according to claim 9, wherein the control unit determines, from among the plurality of communication devices, a communication device corresponding to the power supply efficiency of the wireless power supply based on information relating to the power supply efficiency of the wireless power supply, the time series data, and the transmission timing of the signal.

11. The base station according to claim 10, wherein the control unit selects the other communication device based on the power supply efficiency of the wireless power supply, the time-series data, and the states of the plurality of communication devices.

12. A communication system comprising a communication device that performs wireless power feeding, another communication device, and a base station, wherein the other communication device transmits a first signal to the base station, the communication device receives the first signal as a signal for wireless power feeding, determines time series data corresponding to power feeding efficiency by wireless power feeding, and transmits a second signal including the time series data to the base station, the base station transmits a third signal to the other communication device that includes information regarding signal control according to the time series data, the other communication device transmits a fourth signal to the base station that is controlled based on the information regarding signal control according to the time series data, and the communication device receives the fourth signal as a signal for wireless power feeding.

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