Base station device, terminal device, and wireless communication system

Abstract

A wireless communication system according to the present invention comprises a base station device and a terminal device that wirelessly communicates with the base station device. The base station device transmits a first signal to the terminal device. The terminal device uses a first proportion of received power of the first signal for energy conversion, measures the first signal with a second proportion of the received power of the first signal, and transmits the measurement result of the measurement to the base station device. The base station device determines a transmission parameter of a second signal in accordance with the measurement result and transmits the second signal to the terminal device. The terminal device uses a third proportion of the received power of the second signal for energy conversion and performs processing on the second signal with a fourth proportion of the received power of the second signal.

Description

Base station device, terminal device, and wireless communication system

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

[0002] In recent years, wireless power supply, in which a terminal device converts the energy of a received wireless signal into electrical energy for charging, has been attracting attention in wireless communication systems. Furthermore, there is a technology called power splitting architecture in which the terminal device that receives wireless power splits the received power of the wireless signal, uses one portion for charging, and uses the remaining portion for signal processing such as parsing and decoding the received signal.

[0003] Techniques relating to wireless power supply are described in the following prior art documents.

[0004] Special Publication No. 2023-512675 Publication Special Publication No. 2022-520252

[0005] However, for example, when a certain radio signal transmitted by a base station device is to be subjected to power splitting architecture, the method for determining and notifying the ratio of the received power split in a terminal device has not been determined. If the base station device does not know the ratio of the split, it may not be able to transmit the target radio signal with appropriate transmission power.

[0006] Therefore, one disclosure provides a base station device, a terminal device, and a wireless communication system that can notify the split ratio of received power in a power splitting architecture.

[0007] A wireless communication system having a base station device and a terminal device that communicates wirelessly with the base station device, wherein the base station device transmits a first signal to the terminal device, the terminal device uses a first proportion of the received power of the first signal for energy conversion, measures the first signal at a second proportion of the received power, and transmits the measurement results to the base station device, the base station device determines transmission parameters of a second signal based on the measurement results, and transmits the second signal to the terminal device, and the terminal device uses a third proportion of the received power of the second signal for energy conversion and processes the second signal at a fourth proportion of the received power.

[0008] One disclosure can signal the splitting percentage of received power in a power splitting architecture.

[0009] 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 the processing of signal reception processing S1. FIG. 5 is a diagram showing an example of the sequence of signal reception processing. FIG. 6 is a diagram showing an example of a processing flowchart of first signal reception processing S100. FIG. 7 is a diagram showing an example of a processing flowchart of second signal reception processing S200. FIG. 8 is a diagram showing an example of a processing flowchart of estimation processing S104.

[0010] [First Embodiment] A first embodiment will be described.

[0011] 1 is a diagram showing an example of the configuration of a wireless communication system 10. The wireless communication system 10 includes a base station device 200 and a terminal device 100. The wireless communication system 10 is a system that supports a power splitting architecture in the terminal device 100.

[0012] The base station device 200 is a device that is wirelessly connected to the terminal device 100 and performs wireless communication, and is a communication device capable of wireless communication, such as eNodeB, gNodeB, IAB, Repeater, etc. The base station device 200 configures a communication area A200 where wireless communication is possible.

[0013] The terminal device 100 is a communication device that is wirelessly connected to the base station device 200 and transmits and receives data, and is, for example, a smartphone, a tablet terminal, a personal computer, or a game device. When the terminal device 100 receives a predetermined signal, it performs a power splitting architecture and performs charging processing and signal processing.

[0014] 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, an antenna 240, and a wireless communication circuit 250.

[0015] 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.

[0016] 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.

[0017] The wireless communication circuit 250 is a device that performs wireless communication with the terminal device 100 via the antenna 240. The base station device 200 transmits and receives signals (messages) to and from the terminal device 100 via the wireless communication circuit 250.

[0018] 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.

[0019] The CPU 210 executes the wireless communication control program 221 to configure a control unit and a communication unit and perform wireless communication control processing. The wireless communication control processing is processing for controlling wireless communication with the terminal device 100. In the wireless communication control processing, the base station device 200 establishes a wireless connection with the terminal device 100, transmits signals to the terminal device 100, and receives signals from the terminal device 100.

[0020] The CPU 210 executes a parameter determination module 2211 included in the wireless communication control program 221 to configure a control unit and a communication unit and perform parameter determination processing. The parameter determination processing is processing to determine parameters (transmission parameters) related to transmission such as radio resources of a signal (e.g., PDSCH: Physical Downlink Shared Channel) that transmits data to the terminal device 100. In the parameter determination processing, the base station device 200 determines the parameters based on, for example, a CSI (Channel State Information) report received from the terminal device 100.

[0021] 3 is a diagram illustrating an example of the configuration of the terminal device 100. The terminal device 100 includes a CPU 110, a storage 120, a memory 130, an antenna 140, a wireless communication circuit 150, a power splitter 160, an energy harvester 170, and a storage battery 180.

[0022] 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 and a signal reception program 122.

[0023] 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.

[0024] The wireless communication circuit 150 is a device that performs wireless communication with the base station device 200 via the antenna 140. The terminal device 100 transmits and receives signals (messages) to and from the base station device 200 via the wireless communication circuit 150. When receiving a signal, the terminal device 100 receives the signal with the reception power split by the power splitter 160. When transmitting a signal, the terminal device 100 may transmit the signal from the antenna 140 without going through the power splitter 160.

[0025] The power splitter 160 is a device, such as a distributor, that divides the received power of the signal received by the antenna 140 and delivers the divided received power to the energy harvester 170 and the wireless communication circuit 150. The power splitter 160 divides the received power according to a specified ratio, for example, and outputs it to each device.

[0026] The energy harvester 170 is a power generating device that converts received (input) power into direct current. The energy harvester 170 obtains a portion of the received power of the signal from the power splitter 160, converts it into direct current, and charges the storage battery 180. The converted direct current may also be used directly without being charged.

[0027] The storage battery 180 is a battery that stores power for operating the terminal device 100, and is, for example, a lithium ion battery.

[0028] The CPU 110 executes the wireless communication program 121 to configure a terminal control unit and a terminal communication unit and perform wireless communication processing. The wireless communication processing is processing for establishing a wireless connection with the base station device 200 and performing wireless communication. In the wireless communication processing, the terminal device 100 performs wireless communication with the base station device 200, receives signals transmitted by the base station device 200, and transmits signals to the base station device 200.

[0029] The CPU 110 executes the signal reception program 122 to configure a terminal control unit and a terminal communication unit and perform signal reception processing. The signal reception processing is processing performed when a signal transmitted by the base station device 200 is received. The signal reception processing includes, for example, signal processing including signal syntax analysis and decoding of encoded data, and charging processing that generates power using part of the received power of the signal and charges a storage battery.

[0030] The CPU 110 executes a reception power division module 1221 included in the signal reception program 122 to configure a terminal control unit and a terminal communication unit, and perform reception power division processing. The reception power division processing is processing for dividing the reception power of a signal received by the terminal device 100 at a specified ratio.

[0031] The CPU 110 executes the charging module 1222 included in the signal receiving program 122 to configure a terminal control unit and a terminal communication unit and perform charging processing. The charging processing is processing in which power is generated using part of the received power of the signal received by the terminal device 100 and the storage battery is charged.

[0032] The CPU 110 executes the signal module 1223 included in the signal reception program 122 to configure a terminal control unit and a terminal communication unit and perform signal processing. The signal processing is a process of parsing the signal syntax and decoding encoded data. Note that the signal processing is performed using received power other than the received power used in the charging process (the remaining received power used in the charging process).

[0033] <Signal Reception Processing> The signal reception processing S1 will be described. The signal reception processing is processing executed when the terminal device 100 receives a predetermined signal. In the first embodiment, the predetermined signal is a first signal and a second signal. The first signal is, for example, a CSI-RS (Channel State Information - Reference Signal), and the second signal is, for example, a PDSCH.

[0034] 4 is a diagram showing an example of the signal reception process S1. When the terminal device 100 receives a predetermined signal, it performs reception power division process S2.

[0035] The received power division process S2 divides the received signal power into two parts at a predetermined ratio a. The divided received power is used for signal processing S4, and the remaining received power (1-a) is used for charging processing S3.

[0036] The received power NadBm obtained by dividing the received power NdBm of a certain signal by a ratio a can be expressed by, for example, the following equation 1.

[0037] Na = N + 10Log １０ (a) ...Formula 1

[0038] The charging process S3 is a process in which the terminal device 100 generates power using part of the received power of the signal received, and charges the storage battery.

[0039] Signal processing S4 is processing according to the content of the received signal. If the signal is a CSI-RS, for example, measurements are performed according to a reporting policy instructed by the base station device 200, a CSI report is generated, and transmitted to the base station device 200. If the signal is a PDSCH, for example, coded data is decoded and passed to a higher layer.

[0040] 5 is a diagram showing an example of a sequence of signal reception processing. Note that the first signal is CSI-RS and the second signal is PDSCH. Also, the proportion of reception power used for signal processing when receiving CSI-RS is a1, and the proportion of reception power used for signal processing when receiving PDSCH is a2.

[0041] Furthermore, the determination of the ratios a1 and a2 may be initiated by the base station device 200 (hereinafter, may be referred to as base station-initiated) or by the terminal device 100 (hereinafter, may be referred to as terminal-initiated). The sequence is the same in either case. Therefore, after explaining the sequence using Figure 5, the differences in the information elements of each message in the base station-initiated and terminal-initiated cases will be explained.

[0042] <1. Sequence> The base station apparatus 200 transmits RRC (Radio Resource Control) to the terminal apparatus 100 (S10). The RRC transmitted in process S10 includes, for example, a configuration (setting information) related to a CSI report.

[0043] Furthermore, the base station device 200 transmits RRC, MAC-CE (Medium Access Control - Control Element), or DCI (Downlink Control Information) to the terminal device 100 (S11). The RRC, MAC-CE, and DCI transmitted in process S11 include, for example, an instruction to transmit a CSI report.

[0044] The base station device 200 transmits the CSI-RS to the terminal device 100 at a predetermined timing (S12). The CSI-RS is a signal for performing CSI measurement and generating a CSI report, and is a first signal that is the target of signal reception processing.

[0045] When the terminal device 100 receives the CSI-RS (S12), it performs first signal reception processing S100. The first signal reception processing S100 is signal reception processing that is executed when the terminal device 100 receives a first signal.

[0046] 6 is a diagram showing an example of a processing flowchart of the first signal reception processing S100. The terminal device 100 divides the received power of the signal in accordance with the ratio a1 (S101).

[0047] The terminal device 100 performs signal processing using the received power divided at the rate a1.

[0048] The terminal device 100 decodes the received first signal (S102).

[0049] The terminal device 100 measures the received power after division (S103).

[0050] The terminal device 100 estimates the received power of the second signal after division (S104). Details of the process S104 for estimating the received power of the second signal will be described later.

[0051] The terminal device 100 creates a report corresponding to the first signal (S105) and transmits the report to the base station device 200. The report is, for example, a CSI report, and is generated in accordance with a configuration (setting information) related to the CSI report included in the RRC.

[0052] On the other hand, the terminal device 100 performs charging processing using the remaining received power (for example, 1-a1) of the received power divided by the ratio a1.

[0053] The terminal device 100 generates power using the received power (S106).

[0054] The terminal device 100 charges the generated power into the storage battery (S107).

[0055] The terminal device 100 executes the signal processing and the charging processing, and ends the first signal reception processing.

[0056] Returning to the sequence in FIG. 5, in the signal processing of the first signal reception processing S100, the terminal device 100 performs CSI measurement and transmits a CSI report to the base station device 200 (S13).

[0057] Upon receiving the CSI report (S13), the base station apparatus 200 performs a parameter determination process S300. The parameter determination process S300 is a process for determining parameters (e.g., frequency, transmission power, etc.) of downlink resources (e.g., PDSCH) according to the content of the CSI report.

[0058] The base station device 200 transmits the DCI to the terminal device 100 (S14). The DCI transmitted in process S14 includes control information such as downlink data transmission (for example, parameters).

[0059] Then, the base station apparatus 200 transmits the PDSCH including the downlink data to the terminal apparatus 100 using the determined parameters (S15).

[0060] When the terminal device 100 receives the PDSCH (S15), it performs second signal reception processing S200. The second signal reception processing S200 is signal reception processing that is executed when the terminal device 100 receives a second signal.

[0061] 7 is a diagram showing an example of a processing flowchart of the second signal reception processing S200. The terminal device 100 divides the received power of the signal in accordance with the ratio a2 (S201).

[0062] The terminal device 100 performs signal processing using the received power divided at the rate a2.

[0063] The terminal device 100 decodes the received second signal (S202).

[0064] The terminal device 100 passes the data included in the signal to an upper layer (S203).

[0065] On the other hand, the terminal device 100 performs charging processing using the remaining received power (for example, 1-a2) of the received power divided at the rate a2.

[0066] The terminal device 100 generates power using the received power (S204).

[0067] The terminal device 100 charges the generated power into the storage battery (S205).

[0068] The terminal device 100 executes the signal processing and the charging processing, and ends the second signal reception processing.

[0069] Here, the process S104 for estimating the received power of the second signal after division will be described. Fig. 8 is a diagram showing an example of a processing flowchart of the estimation process S104.

[0070] The terminal device 100 calculates the received power of the first signal before division using the divided received power and the ratio a1 (S104-1).

[0071] The terminal device 100 estimates the received power of the second signal before division, using the received power of the first signal before division and the transmission power offset between the first signal and the second signal (S104-2).

[0072] The terminal device 100 calculates the received power of the second signal after division using the received power of the second signal before division and the ratio a2 (S104-3), and ends the process.

[0073] The estimated received power of the second signal after division may be used, for example, to determine (including estimation and assumption) the ratio a1, measure CSI, and so on.

[0074] 2. Ratio Notification Methods The following describes the terminal-led and base station-led methods.

[0075] <2.1 Case of Base Station Initiative> In the case of base station initiative, the ratio a1 and the ratio a2 are notified from the base station device 200 to the terminal device 100.

[0076] The messages that can include the ratio a1 are RRC(S10), RRC(S11), MAC-CE(S11), and DCI(S11). In the case of RRC(S10), an information element regarding the ratio a1 is added to the configuration (setting information) related to the CSI report. In the case of RRC(S11), MAC-CE(S11), and DCI(S11), an information element regarding the ratio a1 is added to the instruction to transmit the CSI report.

[0077] The ratio a1 may be set in both the configuration (setting information) related to the CSI report and the instruction to transmit the CSI report, or may be set in only one of them. For example, when it is set in both, the terminal device 100 uses the latest (most recently received) ratio a1.

[0078] Messages that can include the ratio a2 are RRC(S10), RRC(S11), MAC-CE(S11), DCI(S11), and DCI(S14). In the case of RRC(S10), an information element regarding the ratio a2 is added to the configuration (setting information) related to the CSI report. In the case of RRC(S11), MAC-CE(S11), and DCI(S11), an information element regarding the ratio a2 is added to the instruction for transmitting the CSI report. In the case of DCI(S14), an information element regarding the ratio a2 is added to the information related to downlink data transmission.

[0079] The ratio a2 may be set to all of the configuration (setting information) related to the CSI report, the instruction to transmit the CSI report, and the information related to downlink data transmission, or may be set to only one or two of them. For example, if multiple ratios a2 are set, the terminal device 100 uses the latest (most recently received) ratio a2.

[0080] Furthermore, when setting the ratio a2 for information regarding downlink data transmission (when transmitting in DCI (S14)), the base station apparatus 200 may determine the ratio a2 taking into consideration the results of the CSI report.

[0081] 2.2 Terminal-Initiated Case In the terminal-initiated case, the ratios a1 and a2 are notified from the terminal device 100 to the base station device 200 .

[0082] The message in which the ratio a1 can be included is the CSI report (S13). In this case, an information element regarding the ratio a1 is added as an information element of the CSI report. Note that the ratio a1 is the ratio actually used by the terminal device 100.

[0083] The message in which the ratio a2 can be included is the CSI report (S13). In this case, an information element on the ratio a2 is added as an information element of the CSI report. Note that the ratio a2 is a ratio that the terminal device 100 plans to use (decided to use) when receiving the second signal, and is an unused ratio.

[0084] The base station device 200 can instruct the terminal device 100 to use a different rate a2 from the notified rate a2. In this case, the base station device 200 notifies information about the rate a2 in the DCI (S14). The information about the rate a2 is, for example, the value of the rate a2 that the terminal device 100 should use. Also, the information about the rate a2 may be, for example, information about the difference from the rate a2 notified by the terminal device 100. Furthermore, the information about the rate a2 may be, for example, a range of the rate a2 that the terminal device 100 should use.

[0085] 3. Relationship Between CSI Report and Ratio a1 and Ratio a2> The terminal device 100 generates a CSI report in accordance with the reporting mode instructed by the base station device 200, based on the estimated received power of the PDSCH after division.

[0086] In the case of the base station initiative, the base station device 200 generates a CSI report corresponding to the ratio a1 and the ratio a2 specified.

[0087] In the multi-CSI mode, multiple ratios a2 can be set at the initiative of the base station, and in this case, CSI reports corresponding to the multiple ratios a2 are generated.

[0088] In the EH (charging) priority mode, in which the base station takes the initiative to prioritize charging, multiple ratios a2 can be set. In this case, for example, the lowest ratio a2 among CQIs (Channel Quality Indicators) exceeding a specific threshold is selected, and a CSI report corresponding to the selected ratio a2 is generated.

[0089] <Process S104 for Estimating Received Power of Second Signal> The process S104 for estimating received power of the second signal will now be described. Fig. 8 is a diagram showing an example of a processing flowchart of the process S104 for estimating received power of the second signal.

[0090] The terminal device 100 calculates the received power of the first signal before division using the received power of the first signal after division and the ratio a1 (S104-1). Note that, for example, if the received power of the signal can be measured directly, the measured value may be used.

[0091] The terminal device 100 estimates the received power of the second signal before division using the received power of the first signal before division and the transmission power offset of the first signal and the second signal (S104-2). For example, the PDSCH may have a lower transmission power than the CSI-RS due to the transmission power offset.

[0092] The terminal device 100 calculates the received power of the second signal after division using the received power of the second signal before division and the ratio a2 (S104-3), and ends the process.

[0093] In the first embodiment, the base station device 200 can determine downlink data transmission parameters that do not reduce the accuracy of data reception at the terminal device 100 by taking into account the division of received power in CSI measurement and PDSCH scheduling.

[0094] Furthermore, in the first embodiment, the ratios a1 and a2 can be set and notified for various messages, which makes it possible to appropriately respond to changes in wireless quality, for example.

[0095] [Other Embodiments] The first signal and the second signal do not necessarily both need to be target signals for the power splitting architecture. The terminal device 100 and the base station device 200 only need to notify the proportion of the target signals. Furthermore, the terminal device 100 and the base station device 200 may notify which signals are to be targeted for the power splitting architecture. For example, which signals are to be targeted may be determined depending on the time of day or wireless quality.

[0096] Furthermore, the first signal and the second signal may be signals other than those shown in the first embodiment. In that case, the signal processing will be processing according to the type of each signal and the content of the message.

[0097] 10: Wireless communication system 100: Terminal device 110: CPU 120: Storage 121: Wireless communication program 122: Signal reception program 1221: Received power division module 1222: Charging module 1223: Signal module 130: Memory 140: Antenna 150: Wireless communication circuit 160: Power splitter 170: Energy harvester 180: Storage battery 200: Base station device 210: CPU 220: Storage 221: Wireless communication control program 2211: Parameter determination module 230: Memory 240: Antenna 250: Wireless communication circuit

Claims

1. A wireless communication system having a base station device and a terminal device that communicates wirelessly with the base station device, wherein the base station device transmits a first signal to the terminal device, the terminal device uses a first proportion of the received power of the first signal for energy conversion, measures the first signal at a second proportion of the received power, and transmits the measurement results to the base station device, the base station device determines transmission parameters of a second signal based on the measurement results and transmits the second signal to the terminal device, and the terminal device uses a third proportion of the received power of the second signal for energy conversion and processes the second signal at a fourth proportion of the received power.

2. The wireless communication system according to claim 1, wherein the base station device transmits measurement control information regarding the measurement to the terminal device before transmitting the first signal, and the measurement control information includes the first ratio.

3. The wireless communication system according to claim 1, wherein the base station device transmits instruction control information to the terminal device before transmitting the first signal, the instruction control information including the first ratio.

4. The wireless communication system according to claim 1, wherein the base station device transmits downlink control information including the transmission parameters to the terminal device before transmitting the second signal, and the downlink control information includes the third ratio.

5. The wireless communication system according to claim 2, wherein the measurement control information includes the third ratio.

6. The wireless communication system according to claim 3, wherein the instruction control information includes the third ratio.

7. The wireless communication system according to claim 1, wherein the measurement result includes the first ratio.

8. The wireless communication system according to claim 1, wherein the measurement result includes the third ratio.

9. A base station device in a wireless communication system having a base station device and a terminal device that communicates wirelessly with the base station device, the base station device comprising: a communication unit that transmits a first signal and a second signal to the terminal device; and a control unit that determines transmission parameters of the second signal according to measurement results of the first signal in the terminal device, wherein a first proportion of the received power of the first signal in the terminal device is used for energy conversion, the first signal is measured at a second proportion of the received power, and a third proportion of the received power of the second signal in the terminal device is used for energy conversion, and processing of the second signal is performed at a fourth proportion of the received power.

10. A terminal device in a wireless communication system having a base station device and a terminal device that communicates wirelessly with the base station device, the terminal device comprising: a terminal communication unit that receives a first signal and a second signal from the base station device; and a terminal control unit that uses a first proportion of the received power of the first signal for energy conversion and measures the first signal at a received power other than a second proportion, wherein the terminal communication unit transmits the measurement results to the base station device; the terminal control unit uses a third proportion of the received power of the second signal for energy conversion and processes the second signal at a received power of a fourth proportion, and the transmission parameters of the second signal are determined by the base station device according to the measurement results.

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