Terminal equipment, base station equipment, wireless communication system, and wireless communication method

Abstract

To control the transmission power of uplink wireless signals, for example, SRS, at a terminal transmitting and receiving wireless signals to and from a plurality of base stations using the TDD method, based on the path loss between the terminal and the base stations.SOLUTION: A terminal device includes a wireless transmitting / receiving unit that transmits and receives wireless signals using the TDD method to / from a plurality of base stations, and a control unit that controls the transmission power of uplink wireless signals for the plurality of base stations using a weighted average, which is obtained by weighing and averaging path loss between its own terminal device and each of the plurality of base stations.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] Conventionally, in a wireless communication system compliant with the standard specifications of 3GPP (3rd Generation Partnership Project), a reference signal called SRS (Sounding Reference Signal), which is an uplink (from the terminal to the base station) wireless signal, has been used. The transmission power control formula of this SRS is defined in Non-Patent Document 1. In the transmission power control formula of SRS defined in Non-Patent Document 1, the path loss between the terminal and the base station is used.

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, a method for controlling the transmission power of SRS when using SRS in CJT (Coherent joint transmission) of the TDD (Time Division Duplex) system has been studied. In CJT of the TDD system, a UE (User Equipment) communicates with a plurality of transmission and reception points (Multi-TRP). However, when the SRS transmitted by the UE is received by a plurality of transmission and reception points, the path loss between each transmission and reception point and the UE is different. Therefore, when the UE controls the transmission power of SRS, it has been an issue how to determine the path loss between the terminal and the base station in the transmission power control formula of SRS defined in Non-Patent Document 1.

[0005] This invention has been made in consideration of these circumstances, and its purpose is to control the transmission power of uplink radio signals, such as SRS, between the terminal and the base station in a terminal that transmits and receives radio signals with multiple base stations using the TDD method, based on the path loss between the terminal and the base station. [Means for solving the problem]

[0006] One aspect of the present invention includes a wireless transceiver unit that transmits and receives wireless signals to and from a plurality of base stations using a TDD (Time Division Duplex) method, and a control unit that controls the transmission power of the uplink wireless signal to the plurality of base stations using a weighted average value obtained by weighting the path loss between its own terminal device and each of the plurality of base stations. The control unit determines the weights to be used for the weighted average of the path loss based on the measured path loss between each of the plurality of base stations, and transmits the determined weights to the base station to which its terminal device is connected. It is a terminal device. One aspect of the present invention is a terminal device in which the upstream wireless signal is an SRS (Sounding Reference Signal). One aspect of the present invention is a terminal device in which the upstream wireless signal is a PUSCH (Physical Uplink Shared Channel) signal. One aspect of the present invention is a terminal device in which the upstream wireless signal is a PUCCH (Physical Uplink Control Channel) signal.

[0007] One aspect of the present invention comprises a wireless transceiver unit that transmits and receives wireless signals with a terminal that transmits and receives wireless signals with a plurality of base stations using a TDD (Time Division Duplex) method, and a control unit that transmits weights to the terminal that are used for a weighted average used to calculate the path loss when the terminal controls the transmission power of the uplink wireless signal, and the control unit This is based on the reception status of the wireless signal from the terminal at at least one of the multiple base stations. The aforementioned weight decision do It is a base station device. One aspect of the present invention comprises a wireless transceiver unit that transmits and receives wireless signals with a terminal that transmits and receives wireless signals with a plurality of base stations using a TDD (Time Division Duplex) method, and a control unit that receives weights from the terminal used for a weighted average used by the terminal to calculate the path loss when controlling the transmission power of the uplink wireless signal, wherein the weights are based on the measured values ​​of the path loss between the terminal and each of the plurality of base stations. By the aforementioned terminal This is the base station equipment that has been selected. One aspect of the present invention is a base station device in which the uplink radio signal is an SRS (Sounding Reference Signal). One aspect of the present invention is a base station device in which the uplink radio signal is a PUSCH (Physical Uplink Shared Channel) signal. One aspect of the present invention is a base station device in which the uplink radio signal is a PUCCH (Physical Uplink Control Channel) signal.

[0008] One aspect of the present invention comprises a terminal that transmits and receives radio signals to and from a plurality of base stations using a TDD (Time Division Duplex) method, and the plurality of base stations, wherein the terminal controls the transmission power of the uplink radio signal to the plurality of base stations using a weighted average value obtained by weighting the path loss between itself and each of the plurality of base stations. The system includes a control unit, which determines weights to be used for the weighted average of the path loss based on the measured path loss between each of the plurality of base stations, and transmits the determined weights to the base station to which its terminal is connected. It is a wireless communication system.

[0009] One aspect of the present invention is a wireless communication method for a wireless communication system comprising a terminal that transmits and receives wireless signals to and from a plurality of base stations using a TDD (Time Division Duplex) method, wherein the terminal controls the transmission power of the uplink wireless signal to the plurality of base stations using a weighted average value obtained by weighting the path loss between itself and each of the plurality of base stations. The control step includes determining weights to be used for a weighted average of the path loss based on the measured path loss between each of the plurality of base stations, and transmitting the determined weights to the base station to which the terminal is connected. It is a wireless communication method. [Effects of the Invention]

[0010] According to the present invention, in a terminal that transmits and receives radio signals to and from a plurality of base stations by a TDD method, for example, an effect that the transmission power of an uplink radio signal such as SRS can be controlled based on the path loss between the terminal and the base station can be obtained.

Brief Description of the Drawings

[0011] [Figure 1] It is a block diagram showing a configuration example of a wireless communication system according to an embodiment. [Figure 2] It is a diagram for explaining the path loss in a wireless communication system according to an embodiment. [Figure 3] It is a diagram for explaining a path loss calculation method according to an embodiment. [Figure 4] It is a sequence diagram showing an example of the procedure of a wireless communication method according to an embodiment. [Figure 5] It is a diagram for explaining a path loss calculation method according to an embodiment. [Figure 6] It is a sequence diagram showing an example of the procedure of a wireless communication method according to an embodiment. [Figure 7] It is a diagram for explaining a path loss calculation method according to an embodiment. [Figure 8] It is a sequence diagram showing an example of the procedure of a wireless communication method according to an embodiment. [Figure 9] It is a diagram for explaining a path loss calculation method according to an embodiment. [Figure 10] It is a sequence diagram showing an example of the procedure of a wireless communication method according to an embodiment.

Mode for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration example of a wireless communication system according to an embodiment. The wireless communication system shown in FIG. 1 includes a terminal device UE that transmits and receives wireless signals to and from a plurality of base station devices by a TDD (Time Division Duplex) method, and a plurality of base station devices BS. In the example of FIG. 1, as an example of this embodiment, two base station devices BS (TRP#1, TRP#2) are provided, but three or more base station devices BS (TRP#1, TRP#2, TRP#3, ···) may be provided.

[0013] In the wireless communication system of FIG. 1, CJT (Coherent joint transmission) of the TDD method is performed. As CJT of the TDD method, the terminal device UE communicates with two base station devices BS (TRP#1, TRP#2) that are a plurality of transmission and reception points (Multi-TRP).

[0014] The terminal device UE includes an antenna 10, a wireless transmission and reception unit 11, and a control unit 12. The wireless transmission and reception unit 11 transmits and receives wireless signals via the antenna 10. The wireless transmission and reception unit 11 transmits and receives wireless signals to and from two base station devices BS (TRP#1, TRP#2) by the TDD method. The control unit 12 controls the terminal device UE. The control unit 12 uses a weighted average value obtained by weighted-averaging the path losses between its own terminal device UE and each of the two base station devices BS (TRP#1, TRP#2) to control the transmission power of the uplink wireless signal to the two base station devices BS (TRP#1, TRP#2). The uplink wireless signal is, for example, an SRS (Sounding Reference Signal). The uplink wireless signal is, for example, a PUSCH (Physical Uplink Shared Channel) signal. The uplink wireless signal is, for example, a PUCCH (Physical Uplink Control Channel) signal.

[0015] The functions of the terminal device UE are realized by the terminal device UE being equipped with computer hardware such as a CPU (Central Processing Unit) and memory, and the CPU executing computer programs stored in memory. The terminal device UE may be configured using a general-purpose computer device, or it may be configured as a dedicated hardware device. Furthermore, the terminal device UE may utilize mobile communication terminal devices such as smartphones, or tablet computer devices (tablet PCs).

[0016] The base station device BS comprises an antenna 20, a wireless transceiver unit 21, and a control unit 22. The wireless transceiver unit 21 transmits and receives wireless signals via the antenna 20. The wireless transceiver unit 21 transmits and receives wireless signals to and from the terminal device UE using the TDD method. The control unit 22 controls the base station device BS. The control unit 22 of the base station device BS (Serving cell) connected to the terminal device UE, one of the two base station devices BS (TRP#1, TRP#2), transmits weights to the terminal device UE that are used in the weighted average used to calculate the path loss when the terminal device UE controls the transmission power of the uplink wireless signal. These weights are determined based on the reception status of the wireless signal from the terminal device UE in at least one of the two base station devices BS (TRP#1, TRP#2).

[0017] The functions of the base station equipment (BS) are realized by the fact that the base station equipment (BS) is equipped with computer hardware such as a CPU and memory, and the CPU executes computer programs stored in memory. The base station equipment (BS) may be configured using a general-purpose computer device, or it may be configured as dedicated hardware.

[0018] In the following, subscripts such as "a" may be written as "_a".

[0019] Figure 2 is a diagram illustrating the path loss in the wireless communication system shown in Figure 1. In the situation shown in Figure 2(1), the path loss PL_1 between the terminal device UE and the base station device BS (TRP#1), and the path loss PL_2 between the terminal device UE and the base station device BS (TRP#2) are unaffected by the obstruction. On the other hand, in the situation shown in Figure 2(2), where the terminal device UE has moved, the path loss PL_1' between the terminal device UE and the base station device BS (TRP#1) is unaffected by the obstruction, but the path loss PL_2' between the terminal device UE and the base station device BS (TRP#2) fluctuates rapidly due to the obstruction. Therefore, in this embodiment, in order to reflect the fluctuation of the path loss PL_2' in the transmission power control of SRS, etc., the path loss PL used by the terminal device UE when controlling the transmission power of the uplink wireless signal is calculated by a weighted average of path loss PL_1' and path loss PL_2', and the weight used in this weighted average is weighted more heavily on path loss PL_2' than on path loss PL_1'. Specifically, the path loss PL is calculated using the following equations (1) and (2).

[0020]

number

[0021]

number

[0022] Equation (1) is a formula for calculating the path loss PL by taking a weighted average of path losses PL_1' and PL_2'. Equation (2) is a formula for calculating the weights W_1' for path loss PL_1' and W_2' for path loss PL_2', which are used in the weighted average in Equation (1). Path losses PL_1 and PL_2 are path losses at a time earlier than path losses PL_1' and PL_2'. In this embodiment, equation (2) above is used as an example of a weight calculation method, but the method is not limited to this, and any weight calculation method can be applied.

[0023] Next, an embodiment of this specification will be described below.

[0024] [Example 1] Embodiment 1 of this embodiment will be described with reference to Figures 3 and 4. Embodiment 1 is an embodiment relating to the transmission power control of an SRS. Note that the weight values ​​shown in Figures 3 and 4 are examples for illustrative purposes.

[0025] Figure 3 is a diagram illustrating the path loss calculation method in Embodiment 1 according to this embodiment. In the situation shown in Figure 3(1), there is no influence from the shielding on the path loss PL_1 between the terminal device UE and the base station device BS (TRP#1), and on the path loss PL_2 between the terminal device UE and the base station device BS (TRP#2). The control unit 12 of the terminal device UE uses the same value "0.5" for both the weight W_1 of path loss PL_1 and the weight W_2 of path loss PL_2, and calculates the path loss PL by weight average using the path loss calculation formula in equation (1) above.

[0026] On the other hand, in the situation shown in Figure 3(2) where the terminal device UE has moved, the path loss PL_1' between the terminal device UE and the base station device BS (TRP#1) is unaffected by the obstruction, but the path loss PL_2' between the terminal device UE and the base station device BS (TRP#2) fluctuates rapidly due to the obstruction. Therefore, in this embodiment, in order to reflect the fluctuation of path loss PL_2' in the SRS transmission power control, the path loss PL used by the terminal device UE when controlling the SRS transmission power is calculated by a weighted average of path loss PL_1' and path loss PL_2', and the weight used in this weighted average is weighted more heavily on path loss PL_2' than on path loss PL_1'. For example, the control unit 22 of the base station device BS (TRP#2) of the "Coordinated cell" calculates the weight W_1' of path loss PL_1' and the weight W_2' of path loss PL_2' using the weight calculation formula of equation (2) above. The control unit 22 notifies the terminal device UE of the calculated weights W_1' "0.3" and W_2' "0.7" via the base station device BS (TRP#1) of the "Serving cell" (weight change instruction). The control unit 12 of the terminal device UE uses the weights W_1' "0.3" and W_2' "0.7" from the weight change instruction to calculate the path loss PL by weighted average using the path loss calculation formula of equation (1) above.

[0027] Figure 4 is a sequence diagram showing an example of the procedure for the wireless communication method in Embodiment 1 according to this embodiment. The wireless communication method in Embodiment 1 according to this embodiment will be described with reference to Figure 4.

[0028] (Step S101) The control unit 22 of the base station equipment BS (TRP#1) of the "Serving cell" requests "UE capability" from the terminal equipment UE.

[0029] (Step S102) The control unit 12 of the terminal device UE responds to the base station device BS (TRP#1) with "UE capability" information in response to the "UE capability" request.

[0030] (Step S103) The control unit 22 of the base station device BS (TRP#1) performs "RRC signaling" to the terminal device UE. In this "RRC signaling," the "weighted average weight" is notified to the terminal device UE as the "SRS resource" in the "SRS configuration" and "SRS resource set." The weighted average weight is the same value "0.5" for both the weight W_1 on the base station device BS (TRP#1) side and the weight W_2 on the base station device BS (TRP#2) side.

[0031] (Step S104) The control unit 12 of the terminal device UE sends a "RRC signaling" response to the base station device BS (TRP#1).

[0032] (Step S105) The control unit 12 of the terminal device UE uses the weight W_1 "0.5" of the path loss PL_1 and the weight W_2 "0.5" of the path loss PL_2 received from the base station device BS (TRP#1) to calculate the path loss PL by weighted average using the path loss calculation formula of equation (1) above. The control unit 12 uses the calculated path loss PL to control the transmission power of the SRS using the transmission power control formula of the SRS in the following equation (3). The wireless transceiver 11 of the terminal device UE transmits the SRS based on the transmission power control of the SRS by the control unit 12.

[0033]

number

[0034] The transmission power control formula for the SRS in equation (3) above is specified in Non-Patent Document 1.

[0035] (Step S106) The control unit 22 of the base station equipment BS(TRP#2) of the "Coordinated cell" checks the reception status of the SRS transmitted from the terminal equipment UE. The control unit 22 of the base station equipment BS(TRP#2) notifies the base station equipment BS(TRP#1) of the "Serving cell" of the confirmed SRS reception status. Here, the path loss "XXdB" and RSSI "XXdBm" on the base station equipment BS(TRP#2) side are notified to the base station equipment BS(TRP#1) of the "Serving cell" as the SRS reception status.

[0036] (Step S107) The control unit 22 of the base station device BS(TRP#1) uses the SRS reception status notified from the base station device BS(TRP#2) (the previous and current path losses PL_2, PL_2' on the base station device BS(TRP#2) side) and its own SRS reception status (the previous and current path losses PL_1, PL_1' on the base station device BS(TRP#1) side) to calculate the weight W_1' of the path loss PL_1' on the base station device BS(TRP#1) side and the weight W_2' of the path loss PL_2' on the base station device BS(TRP#2) side using the weight calculation formula of equation (2) above. The control unit 22 of the base station device BS(TRP#1) transmits the calculated weight W_1' "0.3" and weight W_2' "0.7" to the terminal device UE (weight change instruction).

[0037] (Step S108) The control unit 12 of the terminal device UE uses the weight W_1' "0.3" of the new path loss PL_1' and the weight W_2' "0.7" of the path loss PL_2' received from the base station device BS (TRP#1) to calculate the path loss PL by weighted average using the path loss calculation formula of equation (1) above. The control unit 12 uses the calculated path loss PL to control the transmission power of the SRS using the transmission power control formula of equation (3) above. The wireless transceiver 11 of the terminal device UE transmits the SRS based on the transmission power control of the SRS by the control unit 12.

[0038] According to Example 1, by dynamically changing the weights of the weighted average used to calculate the path loss PL for SRS transmission power control based on the SRS reception status, it is possible to control the SRS transmission power in accordance with fluctuations in path loss.

[0039] [Example 2] Embodiment 2 of this embodiment will be described with reference to Figures 5 and 6. Embodiment 2 is another embodiment relating to the transmission power control of the SRS. Note that the weight values ​​shown in Figures 5 and 6 are examples for illustrative purposes only.

[0040] Figure 5 is a diagram illustrating the path loss calculation method in Example 2 according to this embodiment. In the situation shown in Figure 5(1), there is no influence from the shielding on the path loss PL_1 between the terminal device UE and the base station device BS (TRP#1), and on the path loss PL_2 between the terminal device UE and the base station device BS (TRP#2). The control unit 12 of the terminal device UE uses the same value "0.5" for both the weight W_1 of path loss PL_1 and the weight W_2 of path loss PL_2, and calculates the path loss PL by weight average using the path loss calculation formula in equation (1) above.

[0041] On the other hand, in the situation shown in Figure 5(2) where the terminal device UE has moved, the path loss PL_1' between the terminal device UE and the base station device BS (TRP#1) is unaffected by the obstruction, but the path loss PL_2' between the terminal device UE and the base station device BS (TRP#2) fluctuates rapidly due to the obstruction. Therefore, in this embodiment, in order to reflect the fluctuation of path loss PL_2' in the SRS transmission power control, the path loss PL used by the terminal device UE when controlling the SRS transmission power is calculated by a weighted average of path loss PL_1' and path loss PL_2', and the weight used in this weighted average is weighted more heavily on path loss PL_2' than on path loss PL_1'. The control unit 12 of the terminal device UE uses the measured values ​​of path loss PL_1 and PL_1' on the base station device BS (TRP#1) side and the measured values ​​of path loss PL_2 and PL_2' on the base station device BS (TRP#2) side to calculate the weight W_1' for path loss PL_1' and the weight W_2' for path loss PL_2' using the weight calculation formula of equation (2) above. The control unit 12 notifies the base station device BS (TRP#1) of the "Serving cell" and the base station device BS (TRP#2) of the "Coordinated cell" of the calculated weight W_1' "0.3" and weight W_2' "0.7" (weight change notification). The base station devices BS (TRP#1, #2) reflect the weight change notification (weight W_1' "0.3", weight W_2' "0.7") in power control processing such as the selection of power control commands in a closed loop. The control unit 12 of the terminal device UE uses the calculated weights W_1' "0.3" and W_2' "0.7" to calculate the path loss PL by weighted average using the path loss calculation formula in equation (1) above.

[0042] Figure 6 is a sequence diagram showing an example of the procedure for the wireless communication method in Embodiment 2 of this embodiment. The wireless communication method in Embodiment 2 of this embodiment will be described with reference to Figure 6.

[0043] (Step S201) The control unit 22 of the base station equipment BS (TRP#1) of the "Serving cell" requests "UE capability" from the terminal equipment UE.

[0044] (Step S202) The control unit 12 of the terminal device UE responds to the base station device BS (TRP#1) with "UE capability" information in response to the "UE capability" request.

[0045] (Step S203) The control unit 22 of the base station device BS (TRP#1) performs "RRC signaling" to the terminal device UE. In this "RRC signaling," the "SRS configuration" and "SRS resource set" are notified to the terminal device UE.

[0046] (Step S204) The control unit 12 of the terminal device UE sends a "RRC signaling" response to the base station device BS (TRP#1).

[0047] (Step S205) The control unit 12 of the terminal device UE calculates the path loss PL by weighted average using the path loss calculation formula of equation (1) above, with weight W_1 "0.5" of path loss PL_1 and weight W_2 "0.5" of path loss PL_2. The values ​​of weights W_1 and W_2 "0.5" are default values. The control unit 12 controls the transmission power of the SRS using the calculated path loss PL and the transmission power control formula of the SRS of equation (3) above. The wireless transceiver 11 of the terminal device UE transmits the SRS with the transmission power controlled by the control unit 12.

[0048] (Step S206) Each base station device BS (TRP#1, TRP#2) transmits a downlink reference signal.

[0049] (Step S207) The control unit 12 of the terminal device UE measures the path loss PL_1' on the base station device BS(TRP#1) side by receiving the downlink reference signal transmitted from the base station device BS(TRP#1), and measures the path loss PL_2' on the base station device BS(TRP#2) side by receiving the downlink reference signal transmitted from the base station device BS(TRP#2). The control unit 12 uses the previous and current measured values ​​of path loss PL_1 and PL_1' on the base station device BS(TRP#1) side, and the previous and current measured values ​​of path loss PL_2 and PL_2' on the base station device BS(TRP#2) side, to calculate the weight W_1' of the path loss PL_1' on the base station device BS(TRP#1) side and the weight W_2' of the path loss PL_2' on the base station device BS(TRP#2) side using the weight calculation formula of equation (2) above. The control unit 12 calculates the path loss PL by weighted average using the path loss calculation formula of equation (1) above, with the newly calculated path loss PL weight W_1' "0.3" and the path loss PL weight W_2' "0.7". The control unit 12 controls the transmission power of the SRS using the calculated path loss PL and the SRS transmission power control formula of equation (3) above. The wireless transceiver 11 of the terminal device UE transmits the SRS with the SRS transmission power controlled by the control unit 12. As an example of this embodiment, the SRS includes a weight change notification that includes the new weights W_1' "0.3" and W_2' "0.7". This allows the SRS to notify each base station device BS (TRP#1, TRP#2) of the weight change and the new weights W_1' "0.3" and W_2' "0.7". In addition, the terminal device UE may, separately from the SRS, notify the base station device BS (TRP#1) of the "Serving cell" and the base station device BS (TRP#2) of the "Coordinated cell" of a weight change notification including the new weights W_1' "0.3" and W_2' "0.7".

[0050] According to Example 2, by dynamically changing the weights of the weighted average used to calculate the path loss PL for SRS transmission power control based on the reception status of the downstream reference signal, SRS transmission power control can be performed in accordance with fluctuations in path loss.

[0051] [Example 3] Embodiment 3 of this embodiment will be described with reference to Figures 7 and 8. Embodiment 3 is an embodiment relating to the transmission power control of the PUSCH signal. Note that the weight values ​​shown in Figures 3 and 4 are examples for illustrative purposes.

[0052] Figure 7 is a diagram illustrating the path loss calculation method in Example 3 of this embodiment. In the situation shown in Figure 7(1), there is no influence from the shielding on the path loss PL_1 between the terminal device UE and the base station device BS (TRP#1), and on the path loss PL_2 between the terminal device UE and the base station device BS (TRP#2). The control unit 12 of the terminal device UE uses the same value "0.5" for both the weight W_1 of path loss PL_1 and the weight W_2 of path loss PL_2, and calculates the path loss PL by weighted average using the path loss calculation formula in equation (1) above.

[0053] On the other hand, in the situation shown in Figure 7(2) where the terminal device UE has moved, the path loss PL_1' between the terminal device UE and the base station device BS(TRP#1) is unaffected by the obstruction, but the path loss PL_2' between the terminal device UE and the base station device BS(TRP#2) fluctuates rapidly due to the obstruction. Therefore, in this embodiment, in order to reflect the fluctuation of path loss PL_2' in the transmission power control of the PUSCH signal, the path loss PL used by the terminal device UE when controlling the transmission power of the PUSCH signal is calculated by a weighted average of path loss PL_1' and path loss PL_2', and the weight used in this weighted average is weighted more heavily on path loss PL_2' than on path loss PL_1'. For example, the control unit 22 of the base station device BS(TRP#1) of the "Serving cell" calculates the weight W_1' of path loss PL_1' and the weight W_2' of path loss PL_2' using the weight calculation formula of equation (2) above. The control unit 22 notifies the terminal device UE of the calculated weights W_1' "0.3" and W_2' "0.7" (weight change instruction). The control unit 12 of the terminal device UE uses the weights W_1' "0.3" and W_2' "0.7" from the weight change instruction to calculate the path loss PL by weighted average using the path loss calculation formula of equation (1) above.

[0054] Figure 8 is a sequence diagram showing an example of the procedure for the wireless communication method in Embodiment 3 of this embodiment. The wireless communication method in Embodiment 3 of this embodiment will be described with reference to Figure 8.

[0055] (Step S301) The control unit 22 of the base station equipment BS (TRP#1) of the "Serving cell" requests "UE capability" from the terminal equipment UE.

[0056] (Step S302) The control unit 12 of the terminal device UE responds to the base station device BS (TRP#1) with "UE capability" information in response to the "UE capability" request.

[0057] (Step S303) The control unit 22 of the base station device BS(TRP#1) performs "RRC signaling" to the terminal device UE. In this "RRC signaling," the "transmit power control" and "weighted average weight" are notified to the terminal device UE. The "weighted average weight" is the same value "0.5" for both the weight W_1 on the base station device BS(TRP#1) side and the weight W_2 on the base station device BS(TRP#2) side.

[0058] (Step S304) The control unit 12 of the terminal device UE sends a "RRC signaling" response to the base station device BS (TRP#1).

[0059] (Step S305) The control unit 12 of the terminal device UE uses the weight W_1 "0.5" of the path loss PL_1 and the weight W_2 "0.5" of the path loss PL_2 received from the base station device BS (TRP#1) to calculate the path loss PL by weighted average using the path loss calculation formula of equation (1) above. The control unit 12 uses the calculated path loss PL to control the transmission power of the PUSCH signal using the PUSCH signal transmission power control formula of equation (4) below. The wireless transceiver 11 of the terminal device UE transmits the PUSCH signal by controlling the transmission power of the PUSCH signal by the control unit 12.

[0060]

number

[0061] The transmission power control formula for the PUSCH signal in equation (4) above is specified in Non-Patent Document 1.

[0062] (Step S306) The control unit 22 of the base station equipment BS(TRP#2) of the "Coordinated cell" checks the reception status of the PUSCH signal transmitted from the terminal equipment UE. The control unit 22 of the base station equipment BS(TRP#2) notifies the base station equipment BS(TRP#1) of the "Serving cell" of the confirmed reception status of the PUSCH signal. Here, the path loss "XXdB" and RSSI "XXdBm" on the base station equipment BS(TRP#2) side are notified to the base station equipment BS(TRP#1) of the "Serving cell" as the reception status of the PUSCH signal.

[0063] (Step S307) The control unit 22 of the base station device BS(TRP#1) uses the reception status of the PUSCH signal notified from the base station device BS(TRP#2) (the previous and current path losses PL_2, PL_2' on the base station device BS(TRP#2) side) and the reception status of its own PUSCH signal (the previous and current path losses PL_1, PL_1' on the base station device BS(TRP#1) side) to calculate the weight W_1' of the path loss PL_1' on the base station device BS(TRP#1) side and the weight W_2' of the path loss PL_2' on the base station device BS(TRP#2) side using the weight calculation formula of equation (2) above. The control unit 22 of the base station device BS(TRP#1) transmits the calculated weight W_1' "0.3" and weight W_2' "0.7" to the terminal device UE (weight change instruction).

[0064] (Step S308) The control unit 12 of the terminal device UE uses the weight W_1' "0.3" of the new path loss PL_1' and the weight W_2' "0.7" of the path loss PL_2' received from the base station device BS (TRP#1) to calculate the path loss PL by weighted average using the path loss calculation formula of equation (1) above. The control unit 12 uses the calculated path loss PL to control the transmission power of the PUSCH signal using the transmission power control formula of the PUSCH signal of equation (4) above. The wireless transceiver 11 of the terminal device UE transmits the PUSCH signal based on the transmission power control of the PUSCH signal by the control unit 12.

[0065] According to Example 3, by dynamically changing the weights of the weighted average used to calculate the path loss PL for controlling the transmission power of the PUSCH signal based on the reception status of the PUSCH signal, the transmission power of the PUSCH signal can be controlled in accordance with fluctuations in the path loss.

[0066] [Example 4] Embodiment 4 of this embodiment will be described with reference to Figures 9 and 10. Embodiment 4 is another embodiment relating to the transmission power control of the PUSCH signal. Note that the weight values ​​shown in Figures 9 and 10 are examples for illustrative purposes only.

[0067] Figure 9 is a diagram illustrating the path loss calculation method in Embodiment 4 according to this embodiment. In the situation shown in Figure 9(1), there is no influence from the shielding on the path loss PL_1 between the terminal device UE and the base station device BS (TRP#1), and on the path loss PL_2 between the terminal device UE and the base station device BS (TRP#2). The control unit 12 of the terminal device UE uses the same value "0.5" for both the weight W_1 of path loss PL_1 and the weight W_2 of path loss PL_2, and calculates the path loss PL by weight average using the path loss calculation formula in equation (1) above.

[0068] On the other hand, in the situation shown in Figure 9(2) where the terminal device UE has moved, the path loss PL_1' between the terminal device UE and the base station device BS (TRP#1) is unaffected by the obstruction, but the path loss PL_2' between the terminal device UE and the base station device BS (TRP#2) fluctuates rapidly due to the obstruction. Therefore, in this embodiment, in order to reflect the fluctuation of path loss PL_2' in the transmission power control of the PUSCH signal, the path loss PL used by the terminal device UE when controlling the transmission power of the PUSCH signal is calculated by a weighted average of path loss PL_1' and path loss PL_2', and the weight used in this weighted average is weighted more heavily on path loss PL_2' than on path loss PL_1'. The control unit 12 of the terminal device UE uses the measured values ​​of path loss PL_1 and PL_1' on the base station device BS (TRP#1) side and the measured values ​​of path loss PL_2 and PL_2' on the base station device BS (TRP#2) side to calculate the weight W_1' for path loss PL_1' and the weight W_2' for path loss PL_2' using the weight calculation formula of equation (2) above. The control unit 12 notifies the base station device BS (TRP#1) of the "Serving cell" of the calculated weight W_1' "0.3" and weight W_2' "0.7" (weight change notification). The base station device BS (TRP#1) reflects the weight change notification (weight W_1' "0.3", weight W_2' "0.7") in power control processing such as the selection of power control commands in the closed loop. The control unit 12 of the terminal device UE uses the calculated weights W_1' "0.3" and W_2' "0.7" to calculate the path loss PL by weighted average using the path loss calculation formula in equation (1) above.

[0069] Figure 10 is a sequence diagram showing an example of the procedure for the wireless communication method in Embodiment 4 of this embodiment. The wireless communication method in Embodiment 4 of this embodiment will be described with reference to Figure 10.

[0070] (Step S401) The control unit 22 of the base station equipment BS (TRP#1) of the "Serving cell" requests "UE capability" from the terminal equipment UE.

[0071] (Step S402) The control unit 12 of the terminal device UE responds to the base station device BS (TRP#1) with "UE capability" information in response to the "UE capability" request.

[0072] (Step S403) The control unit 22 of the base station equipment BS (TRP#1) performs "RRC signaling" to the terminal equipment UE. In this "RRC signaling," "transmit power control" is notified to the terminal equipment UE.

[0073] (Step S404) The control unit 12 of the terminal device UE sends a "RRC signaling" response to the base station device BS (TRP#1).

[0074] (Step S405) The control unit 12 of the terminal device UE calculates the path loss PL by weighted average using the path loss calculation formula of equation (1) above, with weight W_1 "0.5" of path loss PL_1 and weight W_2 "0.5" of path loss PL_2. The values ​​of weights W_1 and W_2 "0.5" are default values. The control unit 12 controls the transmission power of the PUSCH signal using the calculated path loss PL and the transmission power control formula of the PUSCH signal of equation (4) above. The wireless transceiver 11 of the terminal device UE transmits the PUSCH signal based on the transmission power control of the PUSCH signal by the control unit 12.

[0075] (Step S406) Each base station device BS (TRP#1, TRP#2) transmits a downlink reference signal.

[0076] (Step S407) The control unit 12 of the terminal device UE measures the path loss PL_1' on the base station device BS(TRP#1) side by receiving the downlink reference signal transmitted from the base station device BS(TRP#1), and measures the path loss PL_2' on the base station device BS(TRP#2) side by receiving the downlink reference signal transmitted from the base station device BS(TRP#2). Using the previous and current measured values ​​of path loss PL_1 and PL_1' on the base station device BS(TRP#1) side, and the previous and current measured values ​​of path loss PL_2 and PL_2' on the base station device BS(TRP#2) side, the control unit 12 calculates the weight W_1' of the path loss PL_1' on the base station device BS(TRP#1) side and the weight W_2' of the path loss PL_2' on the base station device BS(TRP#2) side using the weight calculation formula of equation (2) above. The control unit 12 uses the newly calculated path loss PL_1' weight W_1' "0.3" and path loss PL_2' weight W_2' "0.7" to calculate the path loss PL by weighted average using the path loss calculation formula of equation (1) above. The control unit 12 uses the calculated path loss PL to control the transmission power of the PUSCH signal using the PUSCH signal transmission power control formula of equation (4) above. The wireless transceiver 11 of the terminal device UE transmits the PUSCH signal based on the transmission power control of the PUSCH signal by the control unit 12. As an example of this embodiment, the PUSCH signal includes a weight change notification that includes the new weights W_1' "0.3" and W_2' "0.7". This allows the PUSCH signal to notify each base station device BS (TRP#1, TRP#2) of the weight change and the new weights W_1' "0.3" and W_2' "0.7". In addition, the terminal device UE may, separately from the PUSCH signal, notify the base station device BS (TRP#2) of the "Coordinated cell" via the base station device BS (TRP#1) of the "Serving cell" of a weight change notification including the new weights W_1'"0.3" and W_2'"0.7".

[0077] According to Example 4, by dynamically changing the weights of the weighted average used to calculate the path loss PL for controlling the transmission power of the PUSCH signal based on the reception status of the downstream reference signal, the transmission power of the PUSCH signal can be controlled in accordance with fluctuations in path loss.

[0078] Furthermore, the above-described embodiments 3 and 4 are also applicable to the PUCCH signal. The transmission power control formula for the PUCCH signal is shown in equation (5). The transmission power control formula for the PUCCH signal in equation (5) is specified in Non-Patent Literature 1.

[0079]

number

[0080] In the embodiment described above, two base station devices BS (TRP#1, TRP#2) were used as an example of multiple transmission / reception points (Multi-TRP), but this can also be applied to three or more base station devices BS (TRP#1, TRP#2, TRP#3, ...).

[0081] According to this embodiment, in a terminal that transmits and receives radio signals with multiple base stations using the TDD method, the transmission power of uplink radio signals such as SRS can be controlled based on the path loss between the terminal and the base station.

[0082] Furthermore, this will enable improvements in overall service quality, such as in wireless networks, and will contribute to Goal 9 of the United Nations-led Sustainable Development Goals (SDGs): "Build resilient infrastructure, promote sustainable industrialization and foster innovation."

[0083] Although embodiments of the present invention have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments, and design modifications and the like are also included within the scope of the gist of the present invention.

[0084] Alternatively, computer programs for realizing the functions of each of the above-mentioned devices may be recorded on a computer-readable recording medium, and the programs recorded on this recording medium may be loaded into a computer system and executed. Note that the term "computer system" here may include hardware such as an operating system and peripheral devices. Furthermore, "computer-readable recording media" refers to writable non-volatile memory such as flexible disks, magneto-optical disks, ROMs, and flash memory, portable media such as DVDs (Digital Versatile Discs), and storage devices such as hard disks built into computer systems.

[0085] Furthermore, "computer-readable recording media" also includes volatile memory (such as DRAM (Dynamic Random Access Memory)) within computer systems that act as servers or clients when programs are transmitted via networks such as the Internet or communication lines such as telephone lines, which retain programs for a certain period of time. Furthermore, the above program may be transmitted from a computer system that stores the program in a memory device or the like to another computer system via a transmission medium or by transmission waves within the transmission medium. Here, the "transmission medium" used to transmit the program refers to a medium that has the function of transmitting information, such as a network (communication network) like the Internet or a communication line (communication line) like a telephone line. Furthermore, the above program may be intended to implement some of the functions described above. It may also be a so-called differential file (differential program) that can implement the aforementioned functions in combination with programs already recorded in the computer system. [Explanation of Symbols]

[0086] UE...Terminal equipment, BS...Base station equipment, 10,20...Antenna, 11,21...Wireless transceiver unit, 12,22...Control unit

Claims

1. A wireless transceiver unit that transmits and receives wireless signals between multiple base stations using the TDD (Time Division Duplex) method, The system includes a control unit that controls the transmission power of the uplink radio signal to the multiple base stations using a weighted average value obtained by weighting the path loss between its own terminal device and each of the multiple base stations, The control unit determines the weights to be used for the weighted average of the path loss based on the measured path loss between it and each of the plurality of base stations, and transmits the determined weights to the base station to which its terminal device is connected. Terminal device.

2. The aforementioned upstream wireless signal is an SRS (Sounding Reference Signal). The terminal device according to claim 1.

3. The aforementioned uplink wireless signal is a PUSCH (Physical Uplink Shared Channel) signal. The terminal device according to claim 1.

4. The aforementioned uplink wireless signal is a PUCCH (Physical Uplink Control Channel) signal. The terminal device according to claim 1.

5. A wireless transceiver unit that transmits and receives wireless signals between multiple base stations and a terminal that transmits and receives wireless signals using the TDD (Time Division Duplex) method, The terminal comprises a control unit that transmits weights to the terminal that are used in a weighted average used to calculate the path loss when the terminal controls the transmission power of the uplink wireless signal, The control unit determines the weight based on the reception status of the radio signal from the terminal at at least one of the plurality of base stations. Base station equipment.

6. A wireless transceiver unit that transmits and receives wireless signals between multiple base stations and a terminal that transmits and receives wireless signals using the TDD (Time Division Duplex) method, The terminal comprises a control unit that receives weights from the terminal used in a weighted average for calculating path loss, which the terminal uses to control the transmission power of the uplink wireless signal, The weight is determined by the terminal based on the measured path loss between the terminal and each of the plurality of base stations. Base station equipment.

7. The aforementioned upstream wireless signal is an SRS (Sounding Reference Signal). The base station device according to any one of claims 5 or 6.

8. The aforementioned uplink wireless signal is a PUSCH (Physical Uplink Shared Channel) signal. The base station device according to any one of claims 5 or 6.

9. The aforementioned uplink wireless signal is a PUCCH (Physical Uplink Control Channel) signal. The base station device according to any one of claims 5 or 6.

10. A terminal that transmits and receives wireless signals between multiple base stations using the TDD (Time Division Duplex) method, The plurality of base stations and, The terminal includes a control unit that controls the transmission power of the uplink radio signal to the multiple base stations using a weighted average value obtained by weighting the path loss between itself and each of the multiple base stations, The control unit determines the weights to be used for the weighted average of the path loss based on the measured path loss between each of the plurality of base stations, and transmits the determined weights to the base station to which its terminal is connected. Wireless communication system.

11. A wireless communication method for a wireless communication system comprising a terminal that transmits and receives wireless signals with multiple base stations using the TDD (Time Division Duplex) method, and the multiple base stations, The terminal includes a control step of controlling the transmission power of the uplink radio signal to the plurality of base stations using a weighted average value obtained by weighting the path loss between itself and each of the plurality of base stations, The control step involves determining weights to be used for the weighted average of the path loss based on the measured path loss between each of the plurality of base stations, and transmitting the determined weights to the base station to which the terminal is connected. Wireless communication method.

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