Communication device, base station device, and wireless communication system

Abstract

The present invention has: a reception unit that receives a reference signal transmitted by each of one or more base station devices and measures reception power corresponding to each of the reference signals; and a control unit that, when the total value of the reception power of each of the reference signals is equal to or greater than a terminal first threshold value, transmits a measurement report including the reception power to a first base station device.

Description

Communication device, base station device, and wireless communication system

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

[0002] For example, a smartphone terminal device has a built-in rechargeable battery that needs to be charged periodically. The terminal device is charged, for example, by connecting a wired cable that supplies power and leaving it for a predetermined period of time. However, depending on the frequency of use of the terminal device, this charging method alone may result in insufficient power. Therefore, currently, wireless power supply to terminal devices in wireless communication systems is being considered.

[0003] Wireless power supply is a charging method that uses a wireless signal received by an antenna to generate a current and charge a rechargeable battery without using a wired cable. In wireless power supply in a wireless communication system, for example, a base station device transmits a wireless signal, a terminal device receives the wireless signal, and the terminal device uses the received wireless signal to charge.

[0004] Techniques relating to wireless power supply are described in the following prior art documents.

[0005] JP 2019-140799 A JP 2023-56738 A

[0006] However, in wireless power supply, the timing at which a base station device transmits a radio signal for power supply and the timing at which a terminal device performs power supply processing have not been determined. Depending on the timing at which the radio signal is transmitted and the timing at which the power supply processing starts, there are cases in which power cannot be supplied to a terminal device efficiently.

[0007] Therefore, one disclosure provides a communication device, a base station device, and a wireless communication system that can perform wireless power supply processing at appropriate timing.

[0008] The base station device includes a receiving unit that receives reference signals transmitted by one or more base station devices and measures the received power corresponding to each of the reference signals, and a control unit that transmits a measurement report including the received power to a first base station device when the total value of the received power of each of the reference signals is equal to or greater than a terminal first threshold.

[0009] One aspect of the present invention is to perform wireless power supply processing at appropriate timing.

[0010] FIG. 1 is a diagram showing an example of the configuration of a wireless communication system 10. FIG. 2 is a diagram showing an example of the configuration of a base station device 200. FIG. 3 is a diagram showing an example of the configuration of a terminal device 100. FIG. 4 is a diagram showing an example of a sequence for starting a power supply operation in a wireless power supply process. FIG. 5 is a diagram showing an example of a processing flowchart for a measurement report control process S200. FIG. 6 is a diagram showing an example of a processing flowchart for a power supply determination process S300. FIG. 7 is a diagram showing an example of a method for calculating a power supply expected value. FIG. 8 is a diagram showing an example of a sequence for stopping a power supply operation in a wireless power supply process.

[0011] [First Embodiment] A first embodiment will be described.

[0012] 1 is a diagram showing an example of the configuration of a wireless communication system 10. The wireless communication system 10 includes base station devices 200-1 and 200-2, a terminal device 100, and a network 300. The wireless communication system 10 is a wireless communication system that supports wireless power supply.

[0013] The base station devices 200-1 and 200-2 (hereinafter sometimes referred to as base station device 200) are devices that are wirelessly connected to the terminal device 100 and perform wireless communication, such as eNodeBs and gNodeBs. The base station device 200 supports wireless power supply and is compatible with communication generations such as 5G, NR (New Radio), and 6G. The base station device 200 may be configured as a single device, or may be configured as multiple devices such as a CU (Central Unit) and DU (Distributed Unit).

[0014] Furthermore, the base station device 200 configures a range (for example, a cell) within which wireless communication with the terminal device 100 is possible. The base station devices 200-1 and 2 transmit reference signals so as to reach the terminal device 100 within their own cells (at an output that is expected to be able to be received by the terminal device 100 with a predetermined power or more). The reference signals are transmitted, for example, by each of the base station devices 200-1 and 2 in the same frequency band (within a frequency band of a predetermined width).

[0015] The terminal device 100 is a communication device, such as a smartphone or a tablet terminal, that wirelessly connects to the base station device 200 and transmits and receives data. The terminal device 100 supports wireless power supply.

[0016] The network 300 is a network that connects the base station devices 200 to each other, and is configured, for example, by the Internet or a core network control device (for example, EPC (Evolved Packet Core)). The base station devices 200-1 and 200-2 communicate with each other via the network 300.

[0017] The base station device 200 transmits a reference signal. The terminal device 100 receives the reference signal and measures the received power. The reference signals measured by the terminal device 100 include, for example, a reference signal transmitted by the base station device 200 with which the terminal device 100 is communicating and a reference signal transmitted by an adjacent base station device 200. The terminal device 100 determines whether to transmit a measurement report using the total received power of the reference signals. The base station device 200 determines whether to start or stop wireless power supply using the received power of the measurement report.

[0018] 2 is a diagram showing an example of the configuration of the base station device 200. The base station device 200 includes a CPU (Central Processing Unit) 210, a storage 220, a memory 230, a wireless communication circuit 250, and a communication circuit 260.

[0019] The storage 220 is an auxiliary storage device that stores programs and data, such as a flash memory, a hard disk drive (HDD), or a solid state drive (SSD). The storage 220 stores a wireless communication control program 221, a power supply determination program 222, and a power supply signal transmission program 223.

[0020] The memory 230 is an area into which the programs stored in the storage 220 are loaded. The memory 230 may also be used as an area in which the programs store data.

[0021] The wireless communication circuit 250 is a device that performs wireless communication with the terminal device 100. The base station device 200 transmits and receives signals (messages) to and from the terminal device 100 via the wireless communication circuit 250. The wireless communication circuit 250 may be used to transmit a power supply signal (a signal used by the terminal device 100 for wireless power supply). The power supply signal may also be transmitted by a circuit (not shown) other than the wireless communication circuit 250 that can transmit wireless signals.

[0022] The CPU 210 is a processor that loads programs stored in the storage 220 into the memory 230, executes the loaded programs, configures each unit, and realizes each process.

[0023] The CPU 210 executes the wireless communication control program 221 to configure a base station control unit and a transmission unit, and to perform wireless communication control processing. The wireless communication control processing is processing for establishing a wireless connection with the terminal device 100 and transmitting and receiving signals via the wireless connection. In the wireless communication control processing, the base station device 200 controls wireless communication.

[0024] The CPU 210 executes the power supply determination program 222 to configure a base station control unit and a transmission unit and perform power supply determination processing. The power supply determination processing is processing that is executed, for example, when a measurement report is received from the terminal device 100, and is processing that determines whether to start power supply based on the measurement results of the terminal device 100. When the base station device 200 determines to start power supply, it thereafter transmits a power supply signal, for example, at a predetermined timing.

[0025] The CPU 210 executes the power supply signal transmission program 223 to configure a base station control unit and a transmission unit, and to perform a power supply signal transmission process. The power supply signal transmission process is, for example, a process of transmitting a power supply signal to the terminal device 100 at a predetermined timing after determining to start power supply.

[0026] 3 is a diagram showing an example of the configuration of the terminal device 100. The terminal device 100 includes a CPU 110, a storage 120, a memory 130, and a wireless communication circuit 150.

[0027] The storage 120 is an auxiliary storage device such as a flash memory, HDD, or SSD that stores programs and data. The storage 120 stores a wireless communication program 121, a measurement report control program 122, and a provisioning operation program 123.

[0028] The memory 130 is an area into which the programs stored in the storage 120 are loaded. The memory 130 may also be used as an area in which the programs store data.

[0029] The wireless communication circuit 150 is a device that performs wireless communication with the base station device 200. The terminal device 100 transmits and receives signals to and from the base station device 200 via the wireless communication circuit 150. The wireless communication circuit 150 may, for example, receive a power supply signal and perform processing related to power supply. The power supply signal may also be received using a communication circuit (not shown) other than the wireless communication circuit 150, for example, having an antenna for receiving the power supply signal, a rectifier circuit, etc.

[0030] The CPU 110 is a processor that loads programs stored in the storage 120 into the memory 130, executes the loaded programs, configures each unit, and realizes each process.

[0031] The CPU 110 executes the wireless communication program 121 to configure a control unit and a receiving unit and perform wireless communication processing. The wireless communication processing is processing for wirelessly connecting to the base station device 200 and performing communication.

[0032] The CPU 110 executes the measurement report control program 122 to configure a control unit and a receiving unit and to perform measurement report control processing. The measurement report control processing is processing to receive reference signals transmitted by the base station device 200 in communication (the serving cell) and neighboring base station devices 200, measure the received power, and control whether or not to transmit a measurement report depending on the received power.

[0033] <Wireless Power Supply Processing> The wireless power supply processing will now be described. Fig. 4 is a diagram showing an example of a sequence for starting a power supply operation in the wireless power supply processing. Note that, in the terminal device 100, the base station device 200-1 is the PCell (own cell), and the base station device 200-2 is an adjacent base station device that configures an adjacent cell. Note that, although Fig. 4 shows one adjacent base station device, there may be multiple adjacent base station devices.

[0034] For example, in the initial state, the terminal device 100 turns off the power supply operation (S100).

[0035] The base station device 200 transmits an initial setting to the terminal device 100 (S101). The initial setting includes power supply information related to power supply. The power supply information includes, for example, a terminal first threshold value, a terminal second threshold value, and radio resources (such as frequency bands and transmission timings) of reference signals, which will be described below. The initial setting is transmitted, for example, using broadcast information such as an SIB or an RRC message.

[0036] The terminal device 100 receives the reference signal in accordance with the power supply information (S102, S103). For example, the terminal device 100 may determine that the base station device 200 that transmitted the reference signal has been received with a predetermined power or more within a predetermined period of time is a neighboring base station device, and may include measurement results of the reference signals of the base station device 200 of its own cell (PCell) and the neighboring base station device 200 in a measurement report.

[0037] When the terminal device 100 receives reference signals transmitted, for example, within the same frequency band, from the base station device 200 of its own cell and the adjacent base station device 200, the terminal device 100 performs measurement report control processing (S200).

[0038] 5 is a diagram showing an example of a processing flowchart of the measurement report control process S200. The terminal device 100 calculates the total value of the received power of the reference signal (S200-1).

[0039] The terminal device 100 compares the calculated total value with the terminal first threshold and the terminal second threshold (S200-2).

[0040] If the total value is equal to or greater than the terminal first threshold value ("equal to or greater than the terminal first threshold value" in S200-2), the terminal device 100 checks the power supply operation (the state related to the power supply operation of the terminal device 100) (S200-3). If the power supply operation is ON (No in S200-3), the terminal device 100 does not transmit a measurement report and ends the processing. On the other hand, if the power supply operation is OFF (Yes in S200-3), the terminal device 100 transmits a measurement report including the received power of the reference signal to the base station device of its own cell (S200-4) and ends the processing.

[0041] If the total value is equal to or less than the second terminal threshold value ("equal to or less than the second terminal threshold value" in S200-2), the terminal device 100 checks the power supply operation (S200-5). If the power supply operation is OFF (No in S200-5), the terminal device 100 does not transmit a measurement report and terminates the processing. On the other hand, if the power supply operation is ON (Yes in S200-5), the terminal device 100 transmits a measurement report including the received power of the reference signal to the base station device of its own cell (S200-6) and terminates the processing.

[0042] If the total value is less than the terminal first threshold and greater than the terminal second threshold ("otherwise" in S200-2), the terminal device 100 does not transmit a measurement report and ends the process.

[0043] The measurement report may be, for example, a measurement report or another message. The measurement report may also be transmitted, for example, as an RRC message, a MAC CE, or a CSI.

[0044] As described above, the terminal device 100 transmits a measurement report to the base station device 200 as a trigger for turning on or off the power supply operation. The base station device 200 determines whether to turn on or off the power supply operation according to the received power of the reference signal included in the measurement report.

[0045] Returning to the sequence of Figure 4, in the measurement report control process S200, the terminal device 100 calculates the total value of the received power of reference signal S102 and reference signal S103 (S200-1 in Figure 5), determines that the total value is greater than or equal to the terminal first threshold value ("greater than or equal to terminal first threshold value" in S200-2 in Figure 5), and since the power supply operation is OFF (Yes in S200-3 in Figure 5), transmits a measurement report to the base station device 200-1 (S104, S200-4 in Figure 5).

[0046] When the base station device 200 receives the measurement report (S104), it performs a power supply determination process (S300).

[0047] 6 is a diagram showing an example of a processing flowchart of the power supply determination process S300. The base station device 200 calculates a power supply expected value from the received power of the reference signal included in the measurement report and the amount of radio resources used (S300-1).

[0048] 7 is a diagram showing an example of a method for calculating a power supply expected value. Equation 1 is an equation used when the charging effect in the terminal device 100, including the radio resources used for communication, is used as a judgment criterion. The power supply expected value in Equation 1 is a power value (e.g., a value based on a theoretical value or an actual measurement value) predicted to be generated in the terminal device 100 when power supply processing is performed on both the power supply signal and the signal used for communication. Equation 1 is an equation for calculating the power supply expected value using the RSRP (received power) of the reference signal of each cell and the number of REs (resource elements) corresponding to the system bandwidth of the cell.

[0049] Equation 2 is an equation used when the effect of transmitting a power supply signal from the base station device 200 is used as a judgment criterion. The expected power supply value in Equation 2 is a power value predicted to increase in the terminal device 100 when power supply processing is performed using both the power supply signal and the signal used for communication (a power value that increases from when power supply processing is performed using only the signal used for communication). In addition, the expected power supply value in Equation 2 is a power value predicted to occur in the terminal device 100 when power supply processing is performed using only the power supply signal. Equation 2 calculates the expected power supply value using the RSRP of the reference signal of each cell and the number of REs obtained by subtracting the number of REs used for cell communication from the number of REs corresponding to the system bandwidth of the cell.

[0050] Returning to the processing flowchart of FIG. 6, the base station device 200 compares the calculated power supply expected value with the first base station threshold and the second base station threshold in the power supply determination process S300 (S300-2).

[0051] If the power supply expected value is equal to or greater than the first base station threshold value ("equal to or greater than the first base station threshold value" in S300-2), the base station device 200 transmits a power supply start instruction, which is a message instructing the terminal device 100 to turn on the power supply operation (S300-3), and transmits a power supply signal transmission start instruction, which is a message instructing the adjacent base station device 200 to start transmitting a power supply signal (S300-4), and ends the processing.

[0052] If the expected power supply value is equal to or less than the second base station threshold value ("equal to or less than the second base station threshold value" in S300-2), the base station device 200 transmits a power supply stop instruction, which is a message instructing the terminal device 100 to turn off the power supply operation (S300-5), and transmits a power supply signal transmission stop instruction, which is a message instructing the adjacent base station device 200 to stop transmitting the power supply signal (S300-6), and ends the processing.

[0053] If the expected power supply value is less than the first base station threshold and greater than the second base station threshold ("otherwise" in S300-2), the base station device 200 does not transmit an instruction and ends the process.

[0054] Returning to the sequence of FIG. 4, in the power supply determination process S300, the base station device 200 calculates the power supply expected value (S300-1 in FIG. 6), determines that the power supply expected value is equal to or greater than the base station first threshold value ("equal to or greater than the base station first threshold value" in S300-2 in FIG. 6), and transmits a power supply start instruction to the terminal device 100 (S105, S300-3 in FIG. 6).

[0055] Furthermore, in the power supply determination process S300, the base station device 200 transmits a power supply signal transmission start instruction to the base station device 200-2 (S107, S300-4 in FIG. 6).

[0056] When the terminal device 100 receives the power supply start instruction (S105), it turns on the power supply operation (S106).

[0057] The base station device 200-1 and the base station device 200-2 that has received the power supply transmission start instruction start transmitting power supply signals, and transmit the power supply signals at predetermined timings, for example (S108, S109).

[0058] When the terminal device 100 receives a power supply signal while the power supply operation is ON (S108, S109), the terminal device 100 performs a power supply process (S110) and charges the battery of the terminal device 100 itself.

[0059] 8 is a diagram showing an example of a sequence for stopping the power supply operation in the wireless power supply process, in which the power supply operation of the terminal device 100 is assumed to be ON.

[0060] The terminal device 100 receives a reference signal in accordance with the power supply information (S151, S152).

[0061] When the terminal device 100 receives reference signals from the base station device 200 of its own cell and the neighboring base station device 200, the terminal device 100 performs measurement report control processing (S200).

[0062] In the measurement report control process S200, the terminal device 100 calculates the total value of the received power of the reference signal S151 and the reference signal S152 (S200-1 in Figure 5), determines that the total value is less than or equal to the terminal second threshold value ("less than or equal to the terminal second threshold value" in S200-2 in Figure 5), and since the power supply operation is ON (Yes in S200-5 in Figure 5), transmits a measurement report to the base station device 200-1 (S153, S200-6 in Figure 5).

[0063] When the base station device 200 receives the measurement report (S153), it performs a power supply determination process (S300).

[0064] In the power supply determination process S300, the base station device 200 calculates the power supply expected value (S300-1 in Figure 6), determines that the power supply expected value is less than or equal to the base station second threshold value ("less than or equal to the base station second threshold value" in S300-2 in Figure 6), and transmits a power supply stop instruction to the terminal device 100 (S154, S300-5 in Figure 6).

[0065] Furthermore, in the power supply determination process S300, the base station device 200 transmits a power supply signal transmission stop instruction to the base station device 200-2 (S156, S300-6 in FIG. 6).

[0066] When the terminal device 100 receives the power supply stop instruction, it turns off the power supply operation (S155).

[0067] The base station device 200-1 and the base station device 200-2 that has received the power supply transmission stop instruction stop transmitting the power supply signal.

[0068] In the above-described sequence ( FIG. 4 ), the total value of received power in the terminal device 100 is equal to or greater than the terminal first threshold, and the expected power supply value in the base station device 200 is equal to or greater than the base station first threshold, but even if the total value of received power in the terminal device 100 is equal to or greater than the terminal first threshold, there are cases in which the expected power supply value in the base station device 200 does not become equal to or greater than the base station first threshold. Also, in the above-described sequence FIG. 8 , the total value of received power in the terminal device 100 is equal to or less than the terminal second threshold, and the expected power supply value in the base station device 200 is equal to or less than the base station second threshold, but even if the total value of received power in the terminal device 100 is equal to or less than the terminal second threshold, there are cases in which the expected power supply value in the base station device 200 does not become equal to or less than the base station second threshold.

[0069] Furthermore, the first terminal threshold, the second terminal threshold, the first base station threshold, and the second base station threshold may be determined according to, for example, the charging efficiency of the terminal device 100. The charging efficiency is the ratio of the power supplying power to the received power of the wireless signal, and is obtained as Y / X, for example, if a wireless signal of X [mW] is received and a power supplying power of Y [mW] is obtained.

[0070] <Regarding ON / OFF of Power Supply Operation> As described above, the terminal device 100 has a state in which the power supply operation is ON and a state in which the power supply operation is OFF.

[0071] The state in which the power supply operation is ON is, for example, a state in which the terminal device 100 receives a power supply signal and performs power supply processing. When the power supply operation is ON, the terminal device 100 stops processing related to data reception, such as reception processing of a PDCCH, but performs reception processing necessary for measurement reporting, such as reception of a reference signal.

[0072] The state in which the power supply operation is OFF is, for example, a state in which the terminal device 100 does not receive a power supply signal (or receives a power supply signal) and does not perform power supply processing (it is possible to perform power supply processing using a signal other than the power supply signal). When the power supply operation is OFF, the terminal device 100 starts (resumes) the reception processing of the PDCCH that was stopped, for example.

[0073] [Other Embodiments] The determination of switching the power supply operation ON / OFF may take into account, for example, the communication state of the terminal device 100. For example, the determination in process S200-3 of FIG. 5 may be replaced with "the terminal device is not communicating with another communication device, and the power supply operation is OFF." In other words, the terminal device 100 may perform an operation not to start the power supply operation when the terminal device 100 is communicating. Note that the terminal device 100 may determine that the terminal device is not communicating when, for example, the amount of data accumulated in the uplink and downlink buffers is zero.

[0074] Similarly, the base station device 200 may determine whether or not to transmit a power supply start instruction, taking into consideration the communication state of the terminal device 100 .

[0075] In addition, in the above-described embodiments, "greater than or equal to," "less than or equal to," "less than," and "larger than" may be read as "greater than," "less than," "less than or equal to," and "greater than or equal to," respectively.

[0076] 10: Wireless communication system 100: Terminal device 110: CPU 120: Storage 121: Wireless communication program 122: Measurement report control program 123: Supply operation program 130: Memory 150: Wireless communication circuit 200: Base station device 210: CPU 220: Storage 221: Wireless communication control program 222: Power supply determination program 223: Power supply signal transmission program 230: Memory 250: Wireless communication circuit 260: Communication circuit 300: Network

Claims

1. A communications device having: a receiving unit that receives reference signals transmitted by one or more base station devices and measures the received power corresponding to each of the reference signals; and a control unit that transmits a measurement report including the received power to a first base station device when the total value of the received power of each of the reference signals is equal to or greater than a terminal first threshold.

2. The communication device of claim 1, wherein when the first base station device receives the measurement report, if the expected power supply value of the communication device is equal to or greater than a base station first threshold, the first base station device transmits a power supply start instruction to instruct the communication device to start power supply.

3. The communication device according to claim 2, wherein, when the control unit receives the power supply start instruction, the control unit generates power by receiving a power supply signal transmitted by the one or more base station devices, and starts a power supply process to charge a rechargeable battery in the device with the generated power.

4. The communication device according to claim 1, wherein the control unit transmits the measurement report when the total value is equal to or less than a second terminal threshold value.

5. A communication device as described in claim 4, wherein when the first base station device receives the measurement report, if the expected power supply value of the communication device is equal to or less than a base station second threshold, the first base station device transmits a power supply stop instruction to the communication device to stop power supply.

6. The communication device according to claim 3, wherein the power supply expected value is a value corresponding to an amount of power generated by the communication device receiving the power supply signal.

7. The communication device according to claim 3, wherein the power supply expected value is a value corresponding to an amount of power generated by receiving the power supply signal and a signal used for communication.

8. A base station device comprising: a transmitter for transmitting a reference signal; a receiver for receiving a measurement report including a received power of the reference signal from a communication device, the measurement report including a base station device other than the base station device; and a base station control unit for transmitting a power supply start instruction to the communication device to start power supply if, upon receiving the measurement report, the power supply expected value of the communication device is equal to or greater than a base station first threshold value.

9. The base station device according to claim 8, wherein, when transmitting the power supply start instruction, the base station control unit transmits a power supply signal transmission instruction to instruct other base station devices included in the measurement report to transmit a power supply signal, and starts transmitting the power supply signal to the communication device.

10. A wireless communication system having one or more base station devices and a communication device, wherein each of the one or more base station devices transmits a reference signal, the communication device measures the received power of the reference signal, and when a total value of the received power of each of the reference signals is equal to or greater than a terminal first threshold, transmits a measurement report including the received power to a first base station device, and when the first base station device receives the measurement report and the power supply expected value of the communication device is equal to or greater than a base station first threshold, transmits a power supply start instruction to instruct the communication device to start power supply.