Base station, communication device, 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 addition, as a method of wireless power transfer, there is a method in which a power transfer signal is transmitted from a base station to a terminal. Accordingly, in order to efficiently perform wireless power transfer between a communication device and a base station, provided is a base station that performs wireless power transfer, the base station being characterized by comprising: a transmission unit that transmits, to the communication device, a signal including information pertaining to the output control of a signal for wireless power transfer; and a control unit that controls the output of a signal for wireless power transfer to the communication device in accordance with information pertaining to the output control of the signal for wireless power transfer.

Description

Base station, communication device and communication system

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

[0002] A method known as wireless power supply is a contactless method for supplying power to a communication device, in which a base station transmits a wireless power supply signal to a terminal (Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2023-126716

[0004] For example, when wireless power is supplied using a signal transmitted from a base station to a communication device, the power supply needs of the communication device are not taken into consideration. Therefore, for example, if there is a communication device that highly needs power supply, there is a possibility that sufficient power cannot be supplied to the communication device. Furthermore, if a communication device that highly needs power supply runs out of battery and stops operating, services using wireless communication, including wireless power supply, cannot be provided. As a result, unexpected situations may occur for the owner of the communication device and the surrounding environment of the communication device. Therefore, when wireless power is supplied using a signal transmitted from a communication device such as a base station, it is desirable to efficiently select the power supply depending on, for example, the status of the communication device to be powered. In short, when wireless power is supplied using a signal transmitted from a communication device such as a base station, efficient wireless power supply operation is required.

[0005] The disclosed technology has been made in consideration of the above, and aims to perform efficient operation of wireless power feeding.

[0006] In one aspect, a base station that performs wireless power supply is provided, characterized by having: a transmitting unit that transmits a signal including information regarding output control of a first wireless power supply signal to a communication device; and a control unit that controls output of the wireless power supply signal to the communication device in accordance with the information regarding output control of the wireless power supply signal.

[0007] When the base station performs wireless power feeding, the wireless power feeding can be operated efficiently.

[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 diagram of a communication device in the communication system according to the first embodiment. FIG. 3 is a diagram illustrating an example of a functional configuration diagram of a communication device in the communication system according to the first embodiment. FIG. 4 is a diagram illustrating an example of a procedure for wireless power feeding in the first embodiment. FIG. 5 is a diagram illustrating an example of a procedure for wireless power feeding in the first embodiment. FIG. 6 is a diagram illustrating an example of a procedure for wireless power feeding in the second embodiment. FIG. 7 is a diagram illustrating an example of a communication system according to a third embodiment. FIG. 8 is a diagram illustrating an example of a procedure for wireless power feeding in the third embodiment. FIG. 9 is a diagram illustrating an example of a method for controlling a signal output for wireless power feeding in the third embodiment. FIG. 10 is a diagram illustrating an example of a method for controlling a signal output for wireless power feeding in the third embodiment. FIG. 11 is a diagram illustrating an example of a hardware configuration diagram of a communication device in the communication system. FIG. 12 is a diagram illustrating an example of a hardware configuration diagram 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] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a communication device and a communication system disclosed in the present application will be described in detail below 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, and a communication device 200B. The base station 100 forms a cell C10. When the communication device 200A and the communication device 200B are not distinguished from each other, they may be simply referred to as the communication device 200. Although the communication system 1 shown in FIG. 1 has two communication devices 200, this is not limitative and any number of communication devices may be used. This also applies to the following embodiments. The communication device 200 is an example of another communication device.

[0013] The base station 100 may be, for example, a small radio base station (including a micro radio base station, a femto radio base station, etc.) such as a macro radio base station or a pico radio base station, 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 be configured such that the wireless communication function for performing wireless communication with the communication device 200 and the digital signal processing and control function are separated and configured as separate devices. In this case, the device having the wireless communication function can be called an RRH (Remote Radio Head), and the device having the digital signal processing and control function can 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 aforementioned RRH and BBU, the base station 100 may be separated into, for example, a Central Unit (CU), a Distributed Unit (DU), and an RU (Radio Unit). 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 communicates 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 downlink signals, such as a signal for wireless power feeding, a signal for a random access procedure, a signal for an RRC layer, a downlink data signal, and a downlink control signal, to the communication device 200 .

[0019] The receiving unit 112 can receive uplink signals transmitted from the communication device 200, such as random access procedure signals, RRC layer signals, uplink data signals, and uplink control signals.

[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, a downlink data signal and information related to wireless power feeding. Note that the information related to wireless power feeding is, for example, at least one of information related to whether the communication device 200 supports wireless power feeding, information related to the frequency of a signal for wireless power feeding that is compatible with wireless power feeding of the communication device 200, and information related to the priority of wireless power feeding of the communication device 200.

[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 receiver 212 receives downlink signals, such as a signal for wireless power supply, a signal for a random access procedure, a downlink data signal, and a downlink control signal, transmitted from the base station 100. The received signals may also include a signal such as an RS (Reference Signal) 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, an uplink data signal. The storage unit 230 can also store configuration information (or setting information) related to wireless communication transmitted from the base station 100. The storage unit 230 can also store information related to the priority of power supply in wireless power supply.

[0028] Next, a process in which the base station 100 transmits a signal for wirelessly feeding power to the communication device 200 up to the number of times will be described with reference to Fig. 4. Fig. 4 is a diagram showing an example of a procedure in which the communication device 200 performs wireless power feeding in the first embodiment.

[0029] First, the base station 100 performs processing for establishing an RRC (Radio Resource Control) connection if an RRC connection has not been established with the communication device 200. Note that processing similar to that performed when exchanging data signals between the base station 100 and the communication device 200 will be omitted.

[0030] The transmitter 211 of the communication device 200 transmits a signal including information related to wireless power feeding of the communication device 200 to the base station 100 (step S40). Note that the signal transmitted in step S40 is, for example, an RRC layer signal transmitted when an RRC connection is established. Also, the information related to wireless power feeding of the communication device 200 is included in, for example, UECapabilityInformation. Note that the information related to wireless power feeding of the communication device 200 may not include information related to the priority of wireless power feeding of the communication device 200.

[0031] When the receiver 112 of the base station 100 receives a signal including information regarding wireless power feeding of the communication device 200 (step S40), the control unit 120 of the base station 100 determines whether the communication device 200 supports wireless power feeding (step S41).

[0032] Furthermore, the control unit 120 of the base station 100 may set a priority of wireless power feeding to the communication device 200 in response to a signal including information about wireless power feeding of the communication device 200, and store the priority in the storage unit 130 of the base station 100. Next, the base station 100 determines whether or not the communication device 200 will perform wireless power feeding (step S43). Note that, before step S43, the receiving unit 112 of the base station 100 may receive a signal requesting wireless power feeding from the communication device 200 (step S42).

[0033] If it is determined in step S43 that wireless charging of the communication device 200 is to be performed, the transmitter 111 of the base station 100 transmits a signal for wireless power feeding (step S44). Note that if it is determined in step S43 that wireless charging of the communication device 200 is not to be performed, the signal for wireless power feeding is not transmitted in step S44.

[0034] Here, a control flow in step S43 in which the base station 100 determines whether or not to wirelessly feed power to the communication device 200 will be described with reference to Fig. 5. Fig. 5 is a diagram showing an example of a control flow in the base station 100 according to the first embodiment.

[0035] First, the control unit 120 of the base station 100 determines whether or not wireless power supply to the communication device 200 is necessary (step S43). The method of determination will be described later.

[0036] When the control unit 120 of the base station 100 determines that wireless power feeding is not necessary for the communication device 200 (step S43: No), the base station 100 does not feed wireless power to the communication device 200 (step S53). That is, the control unit of the base station 100 performs a first control on the output of a signal for wireless power feeding to the communication device 200, and controls so as not to transmit the signal for wireless power feeding.

[0037] When the control unit 120 of the base station 100 determines that wireless power feeding is necessary for the communication device 200 (step S43: Yes), the control unit 120 of the base station 100 determines whether the priority of wireless power feeding to the communication device 200 is high (step S50). Note that the priority of wireless power feeding to the communication device 200 is determined to be high when it has a value equal to or greater than a predetermined threshold, for example.

[0038] If the priority of wireless power feeding is not high (step S50: No), the transmitter 111 of the base station 100 performs second control on the output of a signal for wireless power feeding to the communication device 200, and transmits the signal for wireless power feeding (steps S52 and S44). Note that the second control, for example, performs control similar to that when the base station 100 transmits a data signal to the communication device 200. Also, the second control controls the output for wireless power feeding to a set predetermined value. Note that a case where the priority of wireless power feeding is not high includes, for example, a case where the priority of wireless power feeding is not set. Note that the controller 120 of the base station 100 may perform first control so as not to transmit a signal for wireless power feeding to a communication device 200 that does not have a high priority.

[0039] If the priority of wireless power feeding is high (step S50: Yes), the transmitter 111 of the base station 100 performs the third control on the output of the signal for wireless power feeding and transmits the signal for wireless power feeding to the communication device 200 (steps S51 and S44). Note that the method of performing the third control on the output of the signal for wireless power feeding will be described in detail below.

[0040] In this way, the base station 100 can wirelessly feed power to the communication device 200 or not. This procedure may be repeated. The procedure may be repeated, for example, when the necessity of wireless power feeding is changed or when a predetermined time has passed. Performing any one of the first to third controls on the output of a signal for wireless power feeding may be collectively described as controlling the output of a signal for wireless power feeding.

[0041] Furthermore, the base station 100 can appropriately set a priority of wireless power supply to the communication device 200 according to information about the status of the communication device 200. Note that information about the status of the communication device 200 may include, for example, a significant decrease in the remaining battery power of the communication device 200, a disaster occurring (or having occurred) near the communication device 200, or the communication device 200 not requiring wireless power supply due to an emergency. Note that the above-mentioned situations are merely examples and are not limited to the above. Furthermore, a predetermined value may be set as an initial priority value. Furthermore, these priorities may be, for example, not limited to a single value but may be a combination of multiple values ​​(multiple perspectives), and each value (perspective) may be weighted. The base station 100 may determine the level of priority based on a priority value that has been set or according to the setting. Note that even if the base station 100 has already set a priority for the communication device 200, the base station 100 may set the priority again.

[0042] Furthermore, when the control unit 120 of the base station 100 sets the priority of wireless power feeding of the communication device 200, the transmission unit 111 of the base station 100 transmits a signal including information related to the priority setting to the communication device 200. Note that this information is transmitted, for example, by being included in an RRC message such as RRC setup or RRC reconfiguration.

[0043] When the priority of wireless power feeding of the communication device 200 is set, the control unit 120 of the base station 100 may repeat the procedure of wireless power feeding shown in FIG. 4 from step S40.

[0044] Next, a method for determining whether wireless power feeding is necessary or not, and a method for performing a third control on the output of a signal for wireless power feeding, performed by the control unit 120 of the base station 100, will be described.

[0045] First, a method for determining whether wireless power feeding is necessary will be described. As examples of the method for determining whether wireless power feeding is necessary, three methods will be described: a method for constantly charging the communication device 200; a method for the communication device 200 to determine whether wireless power feeding is necessary; and a method for the base station 100 to determine whether wireless power feeding to the communication device 200 is necessary. Note that these methods are merely examples, and other methods may be used as long as they can determine whether wireless power feeding is necessary. The method to be used for determination may be selected as appropriate, and may be different for each communication device to be fed with power, for example. Furthermore, for example, the method may be switched as appropriate even during one wireless power feeding operation.

[0046] A description will be given of a first example of a method for determining whether wireless power feeding is necessary, which is a method for always charging the communication device 200. In other words, the control unit 120 of the base station 100 always performs processing such that the result of the process in step S40 is Yes.

[0047] In the first example, the transmitter 111 of the base station 100 always transmits a wireless power supply signal and a data signal in parallel to the communication device 200 according to a predetermined setting (for example, by dividing them equally), for example. Note that the transmitter 111 of the base station 100 may transmit a signal including information instructing the base station 100 to periodically transmit a signal including information related to priority determination, such as remaining battery capacity, in order to determine the priority of the communication device 200.

[0048] Next, a second method for determining whether wireless power feeding is necessary, in which the communication device 200 determines whether wireless power feeding is necessary, will be described.

[0049] In the second example, when the control unit 120 of the communication device 200 determines that charging is necessary (for example, when the remaining battery power of the communication device 200 is low), the transmission unit 211 of the communication device 200 transmits a signal including information requesting wireless power feeding to the base station 100. Furthermore, when, for example, the remaining battery power becomes equal to or greater than a predetermined threshold, the transmission unit 211 of the communication device 200 transmits a signal including information requesting the stop of wireless power feeding to the base station 100.

[0050] Next, a third example of the method for determining whether wireless power feeding is necessary, in which the base station 100 determines whether wireless power feeding of the communication device 200 is necessary, will be described.

[0051] In a third example, the transmitter 111 of the base station 100 may transmit a signal including information instructing the communication device 200 to transmit predetermined information to the base station 100. The predetermined information is information related to wireless power supply, such as the remaining battery capacity.

[0052] The control unit 120 of the base station 100 determines whether wireless power feeding is required for the communication device 200 based on the received predetermined information of the communication device 200. Note that, for example, when using information on the remaining battery capacity, a predetermined threshold may be prepared and the necessity of wireless power feeding may be determined by comparing the information with the threshold.

[0053] Next, three examples will be described which are methods for performing the third control on the output of the signal for wireless power feeding when the priority of wireless power feeding of the communication device 200 is high. Note that the methods described below are merely examples, and other methods for controlling the output of the signal for wireless power feeding may also be used.

[0054] An example of the first method is to control the transmission output of the signal to be increased.

[0055] The control unit 120 of the base station 100 controls the transmission power of the signal for wireless power feeding to be increased within the range of frequencies supported by the communication device 200 and within the range that complies with the Radio Act or equivalent laws and regulations in the region where the operation is carried out. For example, the control unit 120 performs a process of changing the first setting related to the transmission power of the signal for wireless power feeding to a second setting related to the transmission power. Note that the transmission power according to the second setting is higher than the transmission power according to the first setting. Note that the transmission power according to the first setting may be, for example, the same power as the transmission power of the data signal that the base station 100 transmits to the communication device 200.

[0056] The transmitting unit 111 of the base station 100 increases the transmission power of the signal in accordance with the setting of the transmission power, and then transmits the signal for wireless power feeding to the communication device 200 .

[0057] This allows the base station 100 to transmit a wireless power supply signal with high transmission power to the communication device 200 with high priority, thereby enabling efficient power supply to the communication device 200 with high priority.

[0058] A second example method is to increase the time allocated to wireless power transmission signals per given time period.

[0059] The base station 100 may transmit signals to communication devices using a time division pattern such as TDD (Time Division Duplex), in which case the base station 100 transmits a different signal for each unit time.

[0060] When it is desired to efficiently wirelessly feed power to a communication device 200 with a high priority, the control unit 120 of the base station 100 sets the allocation time of a wireless power feeding signal to be transmitted to the communication device 200 per predetermined time period to be increased. Note that the initial time division pattern may be a predetermined pattern such as, for example, equally allocating the time to each communication device that the base station 100 is communicating with.

[0061] The transmitting unit 211 of the communication device 200 transmits a signal for wireless power feeding to the communication device 200 during the increased allocated time period that has been set.

[0062] A third example method is to utilize the polarization of the signal.

[0063] First, the transmitter 111 of the base station 100 transmits a signal for performing in-phase addition of the power of two signals for wireless power feeding transmitted in orthogonal polarization to the communication device 200. The signal for performing in-phase addition of the power of two signals for wireless power feeding transmitted in orthogonal polarization is, for example, an RS.

[0064] The control unit 220 of the communication device 200 performs settings for in-phase addition of the power of two wireless power feeding signals transmitted in orthogonal polarizations.

[0065] The control unit 120 of the base station 100 sets the wireless power supply signals for the communication device 200 with a high priority so that the signals are simultaneously transmitted to the communication device 200 using two orthogonal polarized waves in the same band.

[0066] The transmitter 111 of the base station 100 transmits two orthogonally polarized signals for wireless power feeding to the communication device 200 .

[0067] This allows the base station 100 to efficiently supply power to the communication devices 200 with high priority. If the base station 100 does not use this method, for example, the base station 100 does not transmit a signal for wireless power supply using orthogonal polarization.

[0068] As a result, the base station 100 can efficiently wirelessly feed power to the high-priority communication device 200. Note that the three examples described above are merely illustrative, and other methods may be used as long as they provide equivalent effects.

[0069] As described above, the base station 100 determines whether or not wireless power feeding is required for the communication device 200. Then, the base station 100 controls the output of a signal for wireless power feeding in accordance with information related to the priority of wireless power feeding for the communication device 200. By controlling in this manner, for example, the base station 100 can efficiently operate wireless power feeding. Embodiment 2

[0070] In the first embodiment, an example has been described in which the base station 100 determines whether wireless power feeding is necessary for the communication device 200, and controls the output of a signal for wireless power feeding in accordance with information related to the priority of wireless power feeding for the communication device 200. In the second embodiment, a case in which the base station 100 wirelessly feeds power to the communication device 200A and the communication device 200B will be described. Note that in the second embodiment, the communication system 1, the base station 100, and the communication device 200 are the same as those in the first embodiment, and therefore description thereof will be omitted. Furthermore, in the second embodiment, description of the same parts of the procedure of the wireless power feeding method performed by the base station 100 to the communication device 200 as those in the first embodiment will be omitted.

[0071] A control flow for wirelessly feeding power to a communication device 200 in a base station 100 according to the second embodiment will be described with reference to Fig. 6. Fig. 6 is a diagram showing an example of a control flow of the base station 100 according to the second embodiment. Note that processes similar to those described in Fig. 5 are given the same step numbers, and descriptions thereof may be omitted.

[0072] First, the control unit 120 of the base station 100 determines whether or not wireless power feeding to the communication device 200 is necessary (step S43).

[0073] If wireless power feeding is not necessary for the communication device 200 (step S43: No), the base station 100 does not feed wireless power to the communication device 200 (step S53). That is, the control unit 120 of the base station 100 performs a first control on the output of a signal for wireless power feeding to the communication device 200A, and controls so as not to transmit the signal for wireless power feeding.

[0074] If wireless power feeding is required for communication device 200A and communication device 200B (step S43: Yes), control unit 120 of base station 100 determines whether the priority of wireless power feeding for communication device 200A and communication device 200B that require wireless power feeding is high (step S50). Note that the setting of the priority is similar to, for example, the content described in embodiment 1. Note that in FIG. 6, the priority of communication device 200A is assumed to be higher than the priority of communication device 200B. Furthermore, in step S43, a determination is made for each of communication device 200A and communication device 200B.

[0075] If the priority of the communication device 200 is not higher than the reference priority (step S50: No), the base station 100 performs a second control on the output of the signal for wireless power feeding to the communication device 200 (step S52), and transmits the signal for wireless power feeding to the communication device 200 (step S44). Note that the determination in step S50 is made for each of the communication device 200A and the communication device 200B.

[0076] If the priority of the communication device 200 is high (step S50: Yes), the control unit 120 of the base station 100 performs a third control on the output of signals for wireless power supply to all communication devices 200 with high priority or above a threshold, and determines whether or not it is possible to transmit signals for wireless power supply (step S60).

[0077] When the base station 100 is able to perform the third control on the output of the wireless power feeding signal to all of the communication devices 200 with high priority and transmit the wireless power feeding signal (step S60: Yes), the control unit 120 of the base station 100 performs the third control on the output of the wireless power feeding signal to the communication devices 200 (step S51). Then, the transmission unit 111 of the base station 100 transmits the wireless power feeding signal (step S44). For example, when it is determined that both the communication device 200A and the communication device 200B have high priority, the control unit 120 performs the third control on the wireless power feeding signal to be transmitted to each of the communication devices 200A and 200B.

[0078] If the base station 100 performs the third control on the output of wireless power supply signals for all communication devices 200 with high priority and is unable to transmit wireless power supply signals (step S60: No), the control unit 120 of the base station 100 compares the wireless power supply priorities of the communication devices 200 and determines whether the communication device 200 has a higher priority than the other communication devices (step S61). For example, the control unit 120 compares the priorities of the communication devices 200A and 200B. Note that, for example, if the third control is possible for only one of the communication devices 200A and 200B, the control unit 120 of the base station 100 determines in step S61 that the communication device 200A has a higher priority. On the other hand, the control unit 120 of the base station 100 determines in step S61 that the communication device 200B does not have a higher priority. Alternatively, in step S61, the control unit 120 of the base station 100 may determine that a predetermined number of the communication devices with the highest priority have a higher priority. For example, if there are five communication devices 200 and the third control can be executed for two of the communication devices 200, the control unit 120 of the base station 100 determines that the top two communication devices 200 have high priority among the five communication devices 200. Note that a case where it is not possible to control the output of a wireless power feeding signal to transmit the wireless power feeding signal to all of the communication devices 200 may occur, for example, when there is a functional limit of the base station 100.

[0079] Furthermore, when the priorities of communication device 200A and communication device 200B are equal, control unit 120 of base station 100 determines communication device 200 that will perform a third control on the output of signals for wireless power supply according to a predetermined setting (e.g., a setting to select randomly, a setting to apply round robin, etc.).

[0080] If the priority of the communication device 200 is higher than that of the other communication devices (step S61: Yes), the control unit 120 of the base station 100 performs a third control on the output of a signal for wireless power feeding to the communication device 200 (step S51). The transmitter 111 then transmits the signal for wireless power feeding (step S44). If the priority of the communication device 200 is not higher (lower) than that of the other communication devices (step S61: No), the control unit 120 of the base station 100 performs a second control on the output of the signal for wireless power feeding. The transmitter 111 then transmits the signal for wireless power feeding (step S44). Note that the base station 100 may not transmit a signal for wireless power feeding to the other communication device 200 (perform a first control on the output of the signal for wireless power feeding) due to, for example, functional limitations of the base station 100.

[0081] The setting of the priority of the communication device 200 by the control unit 120 of the base station 100 is the same as in the first embodiment.

[0082] As described above, in the second embodiment, the base station 100 can compare the priorities of the plurality of communication devices 200 and control the output of the signal for wireless power feeding to the communication devices 200. Therefore, it is possible to perform an efficient operation of wireless power feeding. Embodiment 3

[0083] In the first embodiment, an example was described in which the base station 100 determines whether wireless power feeding is necessary for the communication device 200, and controls the output of a signal for wireless power feeding in accordance with information related to the priority of wireless power feeding for the communication device 200. In the second embodiment, a case in which the base station 100 wirelessly feeds power to a plurality of communication devices 200 was described. In the third embodiment, a case in which a plurality of base stations 100 wirelessly feed power to a single communication device 200 will be described. Note that in the third embodiment, the base station 100 and the communication device 200 are similar, so description thereof will be omitted. Furthermore, in the third embodiment, description of the same parts of the procedure of the wireless power feeding method performed by the base station 100 to the communication device 200 as in the first and second embodiments will be omitted.

[0084] FIG. 7 shows an example of a communication system 2 according to a third embodiment. The communication system 2 includes a base station 100A, a base station 100B, a communication device 200A, and a communication device 200B. The base station 100A forms a cell C10A. 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 may simply be referred to as the base station 100. When the communication device 200A and the communication device 200B are not distinguished from each other, they may simply be referred to as the communication device 200. Although only two base stations 100 are shown in the figure, the number is not limited to two. This also applies to the following embodiments. In this embodiment, the base station 100 wirelessly feeds power to the communication device 200A. However, the communication device 200 may be within the range of the cells C10A and C10B, and is not limited to the communication device 200A. The base station 100B is, for example, an example of another base station 100.

[0085] Next, a method in which the base station 100 wirelessly supplies power to the communication device 200A will be described with reference to Fig. 8. Note that in Fig. 8, descriptions of the same processes as in Fig. 5 will be omitted. Also, in Fig. 8, the communication device 200A corresponds to the communication device 200 in Fig. 5.

[0086] If the priority of wireless power feeding of the communication device 200A is not high (step S50: No), the control unit 120 of the base station 100A performs a second control on the output of a signal for wireless power feeding to the communication device 200A (step S53). Then, the transmission unit 111 transmits the signal for wireless power feeding (step S82). Note that a case where the priority of wireless power feeding is not high also includes, for example, a case where the priority of wireless power feeding is not set. Furthermore, if the second control is performed, step S82 is the same as step S44 in FIG. 5.

[0087] If the priority of wireless power feeding of the communication device 200A is high (step S50: Yes), the control unit 120 of the base station 100A performs a fourth control on the output of a signal for wireless power feeding to the communication device 200A (step S81). Then, the transmission unit 111 of the base station 100A transmits the signal for wireless power feeding (step S82). Note that the fourth control is a process that includes the third control. Furthermore, performing any one of the first, second, and fourth controls on the output of a signal for wireless power feeding may be collectively described as controlling the output of a signal for wireless power feeding.

[0088] Details of the fourth control will now be described with reference to Fig. 9. Fig. 9 is a diagram showing an example of a control flow of the base station 100A in embodiment 3. Note that in Fig. 9, steps S91 to S95 and step S51 may be collectively referred to as the fourth control.

[0089] The control unit 120 of the base station 100A determines whether or not another base station 100 is to be used for wireless power supply to the communication device 200A (step S91).

[0090] If it is determined that another base station 100 is not to be used (step S91: No), the control unit 120 of the base station 100A performs a third control (step S51). Then, the transmission unit 111 of the base station 100A transmits a signal for wireless power feeding to the communication device 200A (step S96). Note that in this case, step S96 is the same process as step S44 in FIG. 5.

[0091] In the following description, the base station 100 that wirelessly feeds power to the communication device 200 together with the base station 100A is referred to as the base station 100B.

[0092] If it is determined that another base station 100 is to be used (step S91: Yes), the transmitter 111 of the base station 100A transmits a signal to the base station 100B instructing it to wirelessly feed power to the communication device 200A and including information about the wireless power feeding (step S92). Note that the destination base station 100 is not limited to the base station 100B, as long as it is able to wirelessly feed power to the communication device 200A. Note that information necessary for wireless power feeding is, for example, information about the timing of transmitting an RS to the communication device 200A.

[0093] The receiving unit 112 of the base station 100A receives, from the base station 100B, a signal including information on the determination result as to whether or not joint wireless power feeding to the communication device 200A is possible (step S93).

[0094] The control unit 120 of the base station 100A determines whether the base station 100B can jointly wirelessly feed power to the communication device 200A (step S94).

[0095] If the base station 100B cannot jointly wirelessly feed power to the communication device 200A (step S94: No), the control unit 120 of the base station 100A performs a third control on the output of a signal for wireless power feeding (step S51). Then, the transmission unit 111 of the base station 100A transmits a signal for wireless power feeding to the communication device 200A (step S96). Note that step S96 is the same process as step S44 in FIG. 5.

[0096] If it is possible to use another base station 100 (step S94: Yes), wireless power feeding is performed using a plurality of base stations 100 (step S95).

[0097] Here, wireless power feeding using a plurality of base stations 100 will be described with reference to Fig. 10. Fig. 10 is a diagram showing an example of a signal flow in a communication system 2 in embodiment 3. In Fig. 10, the same processes as those in Fig. 9 are given the same reference numerals, and descriptions thereof will be omitted. Fig. 10 also shows an example in which a plurality of base stations 100, including a base station 100A and a base station 100B, wirelessly feed power to a communication device 200A.

[0098] The base station 100A selects the base station 100B together with itself as the base station 100 that will wirelessly feed power to the communication device 200A (step S100). Then, the transmitter 111 of the base station 100A transmits a signal to the base station 100B indicating that it will wirelessly feed power to the communication device 200A and including information about the wireless power feeding (step S92).

[0099] The control unit 120 of the base station 100B receives a signal instructing wireless power supply to the communication device 200A and including information necessary for the wireless power supply, and determines whether or not it is possible to jointly supply wireless power to the communication device 200A (step S101).

[0100] In FIG. 10, the following description will be given on the assumption that it is determined in step S101 that wireless power supply is possible.

[0101] The receiving unit 112 of the base station 100A receives from the base station 100B a signal including information on the determination result as to whether or not joint wireless power feeding is possible to the communication device 200A (step S93). Note that in Fig. 10, it is assumed that the signal includes information indicating that wireless power feeding is possible. Therefore, in step S94, the control unit 120 of the base station 100A determines that the base station 100B can jointly wirelessly feed power to the communication device 200A.

[0102] After the control unit 120 of the base station 100A determines that the base station 100B can jointly wirelessly feed power to the communication device 200A, the transmission unit 111 of the base station 100A transmits a signal such as an RS to the communication device 200A (step S102A). Also, after determining in step S101 that joint wireless power feeding is possible, the transmission unit 111 of the base station 100B transmits a signal such as an RS to the communication device 200A (step S102B).

[0103] The receiving unit 212 of the communication device 200A receives signals such as RSs from the base stations 100A and 100B (steps S102A and S102B).

[0104] The control unit 220 of the communication device 200A determines a PMI (Precoding Matrix Indicator) for receiving data signals with the base station 100A and the base station 100B, and a PMI for receiving signals for wireless power feeding, in accordance with the signals received in steps S102A and S102B (step S103). The PMI for receiving data signals is, for example, a power-based PMI. The PMI for receiving signals for wireless power feeding is, for example, a capacity-based PMI.

[0105] The communication device 200A transmits a signal including the two determined PMIs (the PMI for the communication device 200A and the PMI for the communication device 200B) to the base station 100A (step S104). Note that the signal may be transmitted to the base station 100B, or may be transmitted to both the base station 100A and the base station 100B.

[0106] When the base station 100A receives the two PMIs, it performs phase control of the signal according to the two PMIs and sets the communication device 200A to transmit the signal (step S105). If the base station 100B does not receive a signal including information about the two PMIs, the base station 100A transmits a signal including information about phase control of the signal according to the PMI to the base station 100B (step S106).

[0107] In addition, the base station 100B performs signal phase control according to information regarding signal phase control in accordance with the PMI received from the base station 100 (or the two PMIs received from the communication device 200A), and sets the communication device 200A to transmit a signal (step S107).

[0108] The base station 100A and the base station 100B transmit a wireless power supply signal and / or a data signal, the phase of which is controlled in accordance with the setting of the signal phase control according to the PMI, so that the communication device 200A can simultaneously receive the signal and / or the data signal (steps S108A and S108B). Note that, at this time, steps S108A and S108B are the same processes as step S44 in FIG. 5.

[0109] As a result, the signals for wireless power feeding from the base station 100 are added in phase when received by the communication device 200A, and efficient wireless power feeding can be achieved.

[0110] The setting of the priority of the communication device 200 by the control unit 120 of the base station 100 is performed as needed, as described above. The procedure after setting is also the same.

[0111] The above series of procedures allows the base station 100A and the base station 100B to efficiently wirelessly feed power to the communication device 200A. Furthermore, the communication device 200A may use the received wireless power feeding signal and / or data signal to re-determine a PMI for transmitting and receiving the wireless power feeding signal and / or a PMI for receiving the data signal, and transmit the PMI to the base station 100. In this case, the base station 100A and the base station 100B update the phase control settings in accordance with the received PMI, and transmit signals using the updated settings.

[0112] As described above, in the third embodiment, the plurality of base stations 100 controls the output of the signal for wireless power supply in response to the signal from the communication device 200, thereby enabling efficient operation of wireless power supply to the communication device 200. Embodiment 4

[0113] In the first embodiment, an example was described in which the base station 100 determines whether wireless power feeding is necessary for the communication device 200 and controls the output of a signal for wireless power feeding in accordance with information related to the priority of wireless power feeding for the communication device 200. In the second embodiment, a case was described in which the base station 100 wirelessly feeds power to a plurality of communication devices 200. In the third embodiment, a case was described in which the base station 100A and the base station 100B control the output of a signal for wireless power feeding to the communication device 200 to perform efficient wireless power feeding. In the fourth embodiment, a case in which the base station 100A and the base station 100B wirelessly feed power to the communication device 200A and the communication device 200B will be described. Note that in the fourth embodiment, descriptions of the communication system 2, the base station 100, the communication device 200, and the procedure of the wireless power feeding method performed by the base station 100 to the communication device 200, which are the same as those in the first, second, and third embodiments, will be omitted.

[0114] The control unit 120 of the base station 100 determines whether wireless power feeding is necessary for the communication device 200 within its own cell. The method of determination is the same as that described in the first embodiment, and therefore will not be described here. Note that, for example, the control unit 120 of a certain base station 100 may notify other base stations 100 of information on the result of the determination as to whether wireless power feeding is necessary for the communication device 200.

[0115] The control unit 120 of the base station 100 determines the priority of wireless power feeding for the communication device 200 that requires wireless power feeding, as in the third embodiment. Note that, for example, information about the priority of wireless power feeding for the communication device 200 determined by the control unit 120 of a certain base station 100 may be notified to another base station 100.

[0116] The control unit 120 of the base station 100 sets the second control for the output of the signal for wireless power feeding for the communication devices 200 with low priority, as in the case of embodiment 2. Note that, for example, when there are a large number of communication devices 200 with high priority, the first control may be performed so as not to feed wireless power.

[0117] The control unit 120 of the base station 100 performs the fourth control on the output of the signal for wireless power feeding described in the third embodiment for the communication device 200 with a high priority.

[0118] Furthermore, when the base station 100 performs the fourth control on the output of a signal for wireless power feeding to a communication device 200 with a high priority, for example, the communication device 200A, the base station 100 may transmit a signal including information indicating this to a communication device 200 that can communicate with the communication device 200A. The base station 100 that receives this signal may select not to feed wireless power to the communication device 200A by performing the second control or the first control on the signal output, even if it has determined that the fourth control should be performed on the output of the signal for wireless power feeding.

[0119] The setting of the priority of the communication device 200 by the control unit 120 of the base station 100 is performed as needed, as in the case of the first, second and third embodiments. The procedure after the setting is also the same.

[0120] As described above, in the fourth embodiment, in a situation where there are a plurality of base stations 100 and a plurality of communication devices 200, the plurality of base stations 100 can efficiently wirelessly feed power to the communication devices 200 by selecting a wireless power feeding method according to the state of the communication devices 200 and controlling the output of signals for wireless power feeding. Hardware configuration of each device in each embodiment

[0121] The hardware configuration of each device in the communication system 1 and the communication system 2 according to each embodiment will be described with reference to FIGS.

[0122] Fig. 11 is a diagram showing an example of the hardware configuration of base station 100. As shown in Fig. 11, 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.

[0123] 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. 11 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, for example, the network IF 460 .

[0124] 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.

[0125] Fig. 12 is a diagram showing an example of the hardware configuration of communication device 200. As shown in Fig. 12, 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.

[0126] 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 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. Symbol explanation

[0127] 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 Communication device 210 Communication unit 211 Transmitter 212 Receiver 220 Control unit 230 Memory unit 410 Antenna 420 RF circuit 430 CPU 440 DSP 450 Memory 460 Network IF 510 Antenna 520 RF circuit 530 CPU 540 Memory

Claims

1. A base station that performs wireless power feeding, comprising: a transmitter that transmits a signal including information regarding output control of a first wireless power feeding signal to a communication device; and a controller that controls output of the wireless power feeding signal to the communication device in accordance with the information regarding output control of the first wireless power feeding signal.

2. The base station according to claim 1, wherein the information relating to output control of the first wireless power supply signal includes information relating to priority in wireless power supply to the communication device.

3. The base station according to claim 1, further comprising a receiving unit that receives a signal including information relating to output control of a signal for second wireless power supply from the communication device.

4. The base station according to claim 3, wherein the information relating to output control of the second wireless power supply signal includes information indicating that the communication device is compatible with wireless power supply.

5. The base station according to claim 3, wherein the information relating to output control of the second wireless power supply signal includes information relating to a frequency band supported by the communication device in wireless power supply.

6. The base station according to claim 3, wherein the information relating to output control of the second wireless power supply signal includes information relating to priority in wireless power supply to the communication device.

7. The base station according to claim 3, wherein the control unit changes the priority in wireless power feeding of the communication device according to information relating to output control of the signal for the second wireless power feeding to a priority in wireless power feeding of the communication device according to information relating to output control of the signal for the first wireless power feeding.

8. The base station according to claim 1 or 3, wherein the transmitting unit transmits the wireless power supply signal, the output of which is controlled, to the communication device.

9. The base station according to claim 8, wherein the transmitting unit transmits the two wireless power supply signals in the form of orthogonal polarizations.

10. The base station according to claim 8, wherein the receiving unit receives a signal including information regarding phase control of the signal for wireless power supply from the communication device, and the information regarding phase control of the signal for wireless power supply is information regarding phase control of the signal for wireless power supply transmitted from a plurality of base stations to the communication device.

11. The base station according to claim 10, wherein the control unit controls the phase of the signal for wireless power supply in accordance with information relating to phase control of the signal for wireless power supply transmitted by the plurality of base stations.

12. The base station according to claim 11, wherein the transmitting unit transmits to the plurality of base stations a signal including information regarding phase control of the signal for wireless power supply that is transmitted from the plurality of base stations to the communication device.

13. A base station that performs wireless power feeding, comprising: a receiving unit that receives, from one of a plurality of base stations, a signal including information regarding phase control of a wireless power feeding signal that is transmitted to a communication device by a plurality of communication devices; a control unit that controls the phase of the wireless power feeding signal for the communication device in accordance with the information regarding phase control; and a transmitting unit that transmits the phase-controlled wireless power feeding signal to the communication device.

14. A communication device capable of receiving a signal for wireless power supply, comprising: a receiving unit that receives a signal including information relating to output control of the signal for wireless power supply; and a memory unit that stores information relating to output control of the signal for wireless power supply.

15. A communication system comprising: a base station that performs wireless power supply; and a communication device that can receive a signal for wireless power supply, wherein the base station transmits a signal including information related to output control of the signal for wireless power supply to the communication device; and controls the output of the signal for wireless power supply to the communication device in accordance with the information related to output control of the signal for wireless power supply.

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