Control method, program, and terminal device for performing efficient beam control,

Abstract

This terminal device is configured to: perform first measurement of a prescribed signal that is transmitted by a base station device at a first timing and used for selecting a beam to be used for communicating with the terminal device; if a signal transmitted by the base station device using the same beam as that of the prescribed signal is received at a third timing, perform second measurement based on the signal, the third timing being positioned between the first timing and a second timing corresponding to wireless resources to be used for reporting the result of first measurement; and transmit the result of second measurement to the base station device instead of the result of first measurement if second measurement is performed, or transmit the result of first measurement to the base station device if second measurement is not performed.

Description

Terminal device, control method, and program for performing efficient beam control

[0001] The present invention relates to beam control techniques in cellular communication systems.

[0002] In a fifth-generation (5G) cellular communication system, a base station device and a terminal device can form beams to perform high-capacity communication. In the 5G cellular communication standard, a terminal device measures predetermined signals, such as a Synchronization Signal / Physical Broadcast Channel (SS / PBCH) Block (SSB) and a Channel State Information-Reference Signal (CSI-RS), transmitted in each of a plurality of beams formed by the base station device, and a beam to be used in communication between the base station device and the terminal device is determined based on the measurement results.

[0003] A terminal device reports the radio quality of a predetermined signal from multiple beams formed in a base station device using a physical uplink control channel (PUCCH) in radio resources that the base station device has previously allocated to the terminal device for reporting the radio quality. If the time between the measurement of the predetermined signal and the report is long, a beam that was appropriate at the time of measurement may no longer be appropriate at the time of selection. In other words, for highly accurate beam control, it is important to shorten the time between measurement and report.

[0004] The present invention provides a technique for reducing the time between measuring radio signals for beam selection and reporting the measurement results.

[0005] A terminal device according to one aspect of the present invention has a measurement means that performs a first measurement of a predetermined signal for selecting a beam to be used in communication with the terminal device, which is transmitted by a base station device at a first timing, and performs a second measurement based on the signal when the base station device receives a signal transmitted by the same beam as the predetermined signal at a third timing between the first timing and a second timing corresponding to a radio resource used to report the result of the first measurement; and a transmission means that transmits the result of the second measurement to the base station device instead of the result of the first measurement when the second measurement is performed, and transmits the result of the first measurement to the base station device when the second measurement is not performed.

[0006] According to the present invention, the time between measuring radio signals for beam selection and reporting the measurement results can be reduced.

[0007] Other features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings, in which the same or similar elements are designated by the same reference numerals.

[0008] The accompanying drawings are incorporated in and constitute a part of the specification, illustrate embodiments of the present invention, and, together with the description, are used to explain the principles of the present invention. FIG. 1 is a diagram illustrating an example of the configuration of a wireless communication system. FIG. 2 is a diagram illustrating a conventional example of processing for setting beams that can be used to transmit downlink signals to terminal devices. FIG. 3 is a diagram illustrating an example of the processing flow of the first procedure. FIG. 4A is a diagram illustrating a method for multiplexing measurement results. FIG. 4B is a diagram illustrating a method for multiplexing measurement results. FIG. 4C is a diagram illustrating a method for multiplexing measurement results. FIG. 5 is a diagram illustrating a modified example of the first procedure. FIG. 6 is a diagram illustrating an example of the processing flow of the second procedure. FIG. 7 is a diagram illustrating a modified example of the second procedure. FIG. 8 is a diagram illustrating an example of the hardware configuration of an apparatus. FIG. 9 is a diagram illustrating an example of the functional configuration of a base station apparatus. FIG. 10 is a diagram illustrating an example of the functional configuration of a terminal apparatus.

[0009] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention as claimed, and not all combinations of features described in the embodiments are necessarily essential to the invention. Two or more of the features described in the embodiments may be combined in any desired manner. Furthermore, the same reference numerals are used to designate identical or similar components, and redundant descriptions will be omitted.

[0010] Fig. 1 shows an example of the configuration of a wireless communication system according to this embodiment. The wireless communication system is, for example, a cellular communication system conforming to the fifth generation (5G) cellular communication standard of the Third Generation Partnership Project (3GPP (registered trademark)), and is configured to include a base station device 101 and a terminal device 111. Note that Fig. 1 shows only one base station device and one terminal device, but it goes without saying that a large number of base station devices and a large number of terminal devices may exist.

[0011] The base station device 101 can form multiple beams and provide communication services to the terminal device 111 using some of the multiple beams. The base station device 101 selects one of the multiple beams and transmits a downlink signal to the terminal device 111 using the selected beam. Note that if a different beam is used, the characteristics of the transmission path between the terminal device 111 and the base station device 101 will differ, and the decoding process of the downlink signal to be performed in the terminal device 111 will also differ. For this reason, when transmitting a downlink signal, the base station device 101 notifies the terminal device 111 of which beam the signal was transmitted using, using downlink control information (DCI). Here, since the base station device 101 can configure multiple beams, in a situation where all of the beams can be used, it is not possible to uniquely identify the beam used to transmit the downlink signal using the limited number of DCI bits. For this reason, a beam that can be used to transmit a downlink signal to the terminal device 111 can be selected from the multiple beams available to the base station device 101 and configured in advance in the terminal device 111. The flow of this process will be described using FIG. 2.

[0012] It is assumed that the base station device 101 has notified the terminal device 111 in advance of configuration information for the terminal device 111 to measure and report the radio quality (channel state information (CSI)) of a predetermined signal for selecting a beam to be used between the base station device 101 and the terminal device 111, which is transmitted by the base station device 101 using each beam. This configuration information is notified, for example, using a radio resource control (RRC) message such as an RRC Reconfiguration message. Thereafter, the base station device 101 can instruct the terminal device 111 to measure the radio quality (S201). This measurement instruction is transmitted to the terminal device 111, for example, using a medium access control element (MAC CE) or DCI. It is noted that the measurement and reporting instructions may be issued together with the configuration information. That is, upon receiving the configuration information from the base station device 101, the terminal device 111 may perform measurement and reporting based on the configuration information without receiving a separate instruction. The terminal device 111 measures the radio quality of a reference signal, such as at least one of an SSB (Synchronization Signal / Physical Broadcast Channel (SS / PBCH) Block) and a CSI-RS (Channel State Information-Reference Signal), transmitted from the base station device 101 (S202, S203). After performing the measurement, the terminal device 111 transmits the measurement result to the base station device 101 via a pre-configured physical uplink control channel (PUCCH) (S204).

[0013] The base station device 101 uses the result of the report received in S204 to determine one or more beams to be enabled (made available) for downlink signal transmission to the terminal device 111 from among multiple beams that the base station device 101 can use for transmitting downlink signals (S205). Each of the multiple beams that the base station device 101 can form is associated with a Transmission Configuration Indication (TCI). Then, the beams that can be used for transmitting downlink signals to the terminal device 111 are set by enabling a TCI state that indicates the state of the TCI. For example, the TCI state of a beam heading in a direction significantly different from the direction of the terminal device 111 is disabled, and the TCI state of at least some of the beams heading toward the direction of the terminal device 111 is enabled. Each TCI can be associated with a reference signal to be measured. For example, in the example of FIG. 1, TCI0 ​​to TCI8 may be associated with CSI-RS, and TCI9 to TCI11 may be associated with SSB. Note that TCIn means TCI stateid=n. A different reference signal is associated with each of multiple TCIs having different TCI stateids. That is, CSI-RS based on different radio resources (frequency and time resources) or sequences may be associated with TCI0 ​​to TCI8, and SSB based on different radio resources or sequences may be associated with TCI9 to TCI11. The base station device 101 notifies the terminal device 111 of configuration information for these reference signals, and the terminal device 111 can measure these reference signals based on the configuration information. Furthermore, when the base station device 101 and the terminal device 111 communicate using multiple cells, the TCIs used by each cell may be associated with reference signals provided by another cell, rather than with reference signals provided by the cell. In this case, information for identifying which cell's TCI is associated with which reference signal provided by which cell can be notified to the terminal device 111.

[0014] Then, the base station device 101 transmits to the terminal device 111 a MAC CE including information specifying one or more beams determined to be enabled for downlink signal transmission to the terminal device 111 (S206). The base station device 101 may notify the terminal device 111 of a TCI stateid specifying one or more beams to be enabled. The base station device 101 may notify the terminal device 111 of information such as a bitmap indicating enabled or disabled as the TCI state corresponding to each of multiple beams formed by the base station device 101. Thereafter, when transmitting a downlink signal (e.g., a physical downlink shared channel (PDSCH) or a physical downlink control channel (PDCCH)) to the terminal device 111, the base station device 101 selects a beam to be used from the one or more beams determined to be enabled in S205. Then, the base station device 101 includes information specifying the beam to be used in DCI in the PDCCH to be transmitted when transmitting the downlink signal, and transmits the DCI to the terminal device 111 (S207).

[0015] In this way, to set a downlink beam, the terminal device 111 needs to receive a CSI measurement and report instruction from the base station device 101, report the CSI, and receive designation of one or more beams determined to be activated based on the results of the report. Thus, a certain amount of time is required to set an appropriate beam between the base station device 101 and the terminal device 111. Furthermore, if the time between measurement and actual communication is long, the radio environment at the time of measurement may differ significantly from that at the time of communication. In this case, the beam to be used may not be selected appropriately, resulting in reduced communication efficiency.

[0016] In view of the above circumstances, the present embodiment provides a method for shortening the time from measurement to selection and use of a beam. More specifically, the present embodiment provides a procedure for shortening the time from measurement in S202 to reporting in S204, for example.

[0017] (Processing Flow) In a first procedure, when the terminal device 111 has an opportunity to transmit an uplink signal at a timing earlier than a preset timing, the terminal device 111 transmits at least a portion of the measurement results of the reference signal transmitted from the base station device 101 at that opportunity. For example, the terminal device 111 determines whether a second radio resource is available for transmitting the uplink signal at a second timing after the reference signal measurement timing and before the first timing corresponding to the (preset) first radio resource used for reporting the measurement. Then, the terminal device 111 transmits at least a portion of the measurement results using the second radio resource, provided that the second radio resource is available. For example, the terminal device 111 can transmit all of the measurement results using the second radio resource. This can shorten the time difference between the timing at which the terminal device 111 measures the reference signal and the timing at which the report is made, enabling communication using an appropriate beam between the base station device 101 and the terminal device 111. Note that the terminal device 111 may not transmit anything using the first radio resource. Alternatively, the terminal device 111 may transmit a small amount of information, such as information indicating whether the radio quality (for at least some of the multiple beams) has improved or deteriorated, to the base station device 101 using the second radio resource, and then transmit the remaining information (e.g., information indicating the value of the radio quality) to the base station device 101 using another radio resource thereafter. Here, the other radio resource after the second radio resource may be the first radio resource preconfigured for measurement reporting, or may be another radio resource. For example, when a third radio resource that is later than the second radio resource but earlier than the first radio resource is available for uplink communication, the terminal device 111 may transmit part of the measurement results to the base station device 101 using the second radio resource, and transmit the remaining information to the base station device 101 using the third radio resource.In addition, for example, if the difference between the first timing and the second timing is less than a predetermined value (if there is not a large difference), the terminal device 111 may not report the measurement results at the second timing, but may report the measurement results at the first timing, which is the original reporting timing.

[0018] The preset first radio resource is, for example, a PUCCH preset for measurement reporting. On the other hand, the second radio resource is a PUCCH or a physical uplink shared channel (PUSCH) that is not preset for measurement reporting. As an example, the terminal device 111 can use, as the second radio resource, a radio resource for transmitting a composite automatic repeat request acknowledgement (HARQ-ACK) to the base station device 101 after receiving a PDSCH from the base station device 101. An example of the flow of this process is shown in FIG. 3. In this process example, the terminal device 111 measures a reference signal such as an SSB or CSI-RS transmitted from the base station device 101 (S202, S203), and then receives a PDSCH (S301) that generates a HARQ-ACK transmission before the preset radio resource (S204) for transmitting the measurement result to the base station device 101. In response to receiving this PDSCH, the terminal device 111 transmits a HARQ-ACK, and at the same time, transmits at least a part of the measurement result (S302). Note that the terminal device 111 transmits the measurement result in radio resources that can be used to transmit this HARQ-ACK, but may transmit the measurement result in resources that are different in frequency or time from the radio resources on which the HARQ-ACK is actually transmitted. Furthermore, the terminal device 111 can multiplex at least a part of the measurement result onto the HARQ-ACK to be transmitted by modulating the HARQ-ACK to be transmitted using information indicating the measurement result.

[0019] 4A to 4C show examples of HARQ-ACK modulation. For example, as shown in FIG. 4A, the terminal device 111 changes the subcarrier on which the HARQ-ACK is transmitted based on information indicating the measurement result. That is, the terminal device 111 can transmit the information indicating the measurement result by frequency-modulating the HARQ-ACK. The base station device 101 can identify which subcarrier the HARQ-ACK information is transmitted on and demultiplex the information indicating the measurement result and the HARQ-ACK information to obtain each piece of information. Note that FIG. 4A shows an example in which different subcarriers are used when the radio quality of the measurement result has decreased compared to the previously reported value and when it has not. However, more detailed information on the measurement result may also be multiplexed. In this case, the number of available subcarriers is increased, and the terminal device 111 selects one or more subcarriers from the group of subcarriers to use for transmitting the HARQ-ACK, and transmits the selected subcarriers. Here, by associating the subcarrier selection pattern with the information to be transmitted, the terminal device 111 transmits HARQ-ACK using the subcarriers corresponding to the information to be transmitted.Then, the base station device 101 can acquire information on the measurement result according to the pattern on which subcarriers the HARQ-ACK is transmitted.In one example, the terminal device 111 can transmit information on the measurement result by varying the subcarriers on which the HARQ-ACK is transmitted over time in a specific pattern.

[0020] Furthermore, as shown in FIG. 4B, the terminal device 111 may multiplex the measurement result information onto the HARQ-ACK by changing the frequency and time resource for transmitting the HARQ-ACK. That is, the terminal device 111 may multiplex the measurement result information onto the HARQ-ACK by index modulation. In this case, multiple patterns of frequencies and time resources that can be used for transmitting the HARQ-ACK are prepared, and the measurement result information is notified from the terminal device 111 to the base station device 101 depending on which pattern is used. Furthermore, for example, as shown in FIG. 4C, the measurement result information may be multiplexed with the HARQ-ACK by changing (phase modulating) the phase of the constellation on the IQ (in-phase-quadrature) plane of the HARQ-ACK. In the example of Figure 4C, the HARQ-ACK is expressed by +1 or -1, and when information indicating quality degradation is multiplexed, the phase of the HARQ-ACK is changed by 45 degrees on the IQ plane, and when other information is multiplexed, the phase of the HARQ-ACK is changed by -45 degrees on the IQ plane. Note that not only the phase value but also the amplitude value may be changed.

[0021] Alternatively, the value transmitted by the HARQ-ACK may be spread by a code with a predetermined number of bits, and the spreading code used for the spreading may correspond to the measurement result information. That is, the terminal device 111 identifies a code corresponding to the measurement result information from among available codes, and spreads (code-modulates) the HARQ-ACK information using that code. The terminal device 111 may then transmit the spread code using radio resources available for transmitting the HARQ-ACK. In this way, the terminal device 111 can multiplex and transmit the measurement result information onto the HARQ-ACK using various methods. Note that the radio resources available for transmitting the HARQ-ACK are an example of radio resources available for transmitting the measurement result information, and the measurement result information may be transmitted (e.g., multiplexed) using other radio resources available for transmitting uplink signals.

[0022] For example, when radio resources for transmitting user data are allocated to the terminal device 111, the terminal device 111 may transmit the measurement results using the radio resources. That is, when radio resources for transmitting a PUSCH to the base station device 101 are allocated at an earlier timing than the radio resources preset for reporting the measurement results, the terminal device 111 reports the measurement results using the radio resources for PUSCH transmission. FIG. 5 shows an example of the processing flow in this case. The base station device 101 allocates radio resources for PUSCH transmission to the terminal device 111 at an earlier timing than the radio resources preset for reporting the measurement results (S204). The base station device 101 transmits a PDCCH for the allocation (S501). Then, the terminal device 111 transmits a measurement report to the base station device 101 together with user data in the radio resources for PUSCH transmission (S502). The terminal device 111 may transmit the measurement report using a MAC CE, or may transmit the measurement report as user data.

[0023] In addition, for example, when both a radio resource for PUCCH (e.g., for HARQ-ACK) and a radio resource for PUSCH exist at a timing earlier than the preset radio resource for the measurement report, the terminal device 111 may determine which of them to use based on the data amount of the measurement report. That is, when transmitting a measurement report with a small amount of data, such as, for example, a decrease in radio quality, the terminal device 111 may determine to use the radio resource for PUCCH, and when transmitting a measurement report with a relatively large amount of data, such as a value indicating radio quality (e.g., reference signal received power (RSRP) or reference signal received quality (RSRQ)). Furthermore, the terminal device 111 may transmit some information using the radio resource for PUCCH and the remaining information using the radio resource for PUSCH. Furthermore, the terminal device 111 may transmit some information using the radio resource for PUCCH or the radio resource for PUSCH at a timing earlier than the preset radio resource, and transmit the remaining information using the preset radio resource.

[0024] The base station device 101 receives at least a portion of the information on the measurement results at a timing earlier than the preset radio resource, and can use the information to set the beam to be used for communication with the terminal device 111. For example, when the base station device 101 receives a report that the radio quality of a specific beam has deteriorated, the base station device 101 can prevent the beam from being used for communication with the terminal device 111 for at least a certain period of time (for example, until detailed information arrives). Furthermore, when the base station device 101 receives detailed information on the measurement results for a specific beam, it can perform control such as beam selection in the same manner as conventionally.

[0025] In the second procedure, when the base station device 101 transmits a downlink signal (PDSCH) to the terminal device 111 after transmitting a reference signal for beam selection and before the timing corresponding to the radio resource preset for reporting the measurement result of the reference signal, the terminal device 111 performs measurement based on the downlink signal and notifies the base station device 101 of the measurement result. An example of the flow of this process is shown in FIG. 6. The base station device 101 transmits SSB and CSI-RS (S202), and the terminal device 111 measures the radio quality of these reference signals (S203). Then, before the timing of the radio resource preset for measuring the radio quality (S204), the base station device 101 transmits a downlink signal (PDSCH) including user data to the terminal device 111 (S601). The terminal device 111 measures the radio quality using, for example, a demodulation reference signal (DM-RS) transmitted together with the PDSCH (S602). The terminal device 111 performs measurement on the downlink signal transmitted using the beam instructed by the base station device 101 to report the measurement of the reference signal. That is, the beam used for the measurement in S203 and the beam used for the measurement in S602 are the same beam. The terminal device 111 then transmits the radio quality measured in S602, instead of the radio quality measured in S203, to the base station device 101 using radio resources preset for the measurement report in S203 (S204). This allows the base station device 101 to be notified of the measurement results performed at a timing closer to the measurement report timing, even if the timing of the measurement report remains the same as in the past. In this case, the base station device 101 performs control such as beam selection using the received measurement results, as in the past.

[0026] Furthermore, the first procedure and the second procedure may be used in combination. FIG. 7 shows an example of the processing flow in this case. After receiving the measurement configuration and measurement instruction, the terminal device 111 performs a first measurement (S202, S203) on the reference signal to be measured (SSB or CSI-RS) and a second measurement (S601, S602) on other downlink signals (e.g., DM-RS associated with PDSCH). When an opportunity to transmit an uplink signal is obtained at a timing earlier than the radio resource pre-configured for reporting the first measurement, the base station device 101 transmits at least a portion of the measurement results of the second measurement to the base station device 101 at that opportunity (S301, S302). This allows the base station device 101 to quickly and appropriately set a beam to be used for communication with the terminal device 111. Note that the example in FIG. 7 shows an example in which the measurement results are multiplexed with HARQ-ACK, but various modifications of the first procedure, such as using MAC CE as in FIG. 5, can naturally be applied.

[0027] (Device Configuration) FIG. 8 shows an example of the hardware configuration of the base station device 101 and the terminal device 111 according to this embodiment. In one example, the base station device 101 and the terminal device 111 are configured to include a processor 801, a ROM 802, a RAM 803, a storage device 804, and a communication circuit 805. The processor 801 is a computer configured to include one or more processing circuits, such as a general-purpose CPU (Central Processing Unit) or an ASIC (Application Specific Integrated Circuit), and performs the overall processing of the device and each of the above-mentioned processes by reading and executing programs stored in the ROM 802 or the storage device 804. The ROM 802 is a read-only memory that stores information such as programs and various parameters related to the processing performed by the base station device 101 and the terminal device 111. The RAM 803 functions as a workspace when the processor 801 executes a program and is also a random access memory that stores temporary information. The storage device 804 is configured, for example, by a removable external storage device. The communication circuit 805 is configured, for example, by a circuit for wireless communication of 5G or a successor standard. While FIG. 8 illustrates one communication circuit 805, the base station device 101 and the terminal device 111 may have multiple communication circuits. For example, the base station device 101 and the terminal device 111 may have wireless communication circuits for 5G and a successor standard, respectively, and a common antenna for these circuits. The base station device 101 and the terminal device 111 may also have separate antennas suitable for each standard. The base station device 101 may also have a wired communication circuit used when communicating with other base station devices or nodes in the core network. The terminal device 111 may also have a communication circuit compliant with a wireless communication standard other than a cellular communication standard, such as a wireless local area network (LAN) or Bluetooth (registered trademark). The base station device 101 and the terminal device 111 may have separate communication circuits 805 for each of the multiple available frequency bands, or may have a common communication circuit 805 for at least some of the frequency bands.

[0028] FIG. 9 is a diagram illustrating an example of the functional configuration of a base station device 101 according to this embodiment. The base station device 101 includes, as its functions, a reference signal transmitter 901, a report setting unit 902, a communication processing unit 903, a report receiving unit 904, and a beam setting unit 905. Note that FIG. 9 illustrates only functions particularly related to this embodiment, and does not illustrate various other functions that the base station device 101 may have. For example, the base station device 101 naturally has other functions that base station devices compliant with 5G and subsequent standards generally have. The functional blocks in FIG. 9 are illustrated schematically, and each functional block may be integrated or further subdivided. Each function in FIG. 9 may be realized, for example, by a processor 801 executing a program stored in a ROM 802 or a storage device 804, or by a processor within a communication circuit 805 executing predetermined software. Since the details of the processing performed by each functional unit have been described above, the description will not be repeated here, and only the general functions will be outlined.

[0029] The reference signal transmission unit 901 transmits reference signals, such as SSB and CSI-RS, used to select a beam to be used in communication with the terminal device 111. Furthermore, when transmitting a PDSCH, the reference signal transmission unit 901 transmits a DM-RS for demodulating the PDSCH. The report setting unit 902 sets radio resources for the terminal device 111 to report measurement results of SSB, CSI-RS, and the like transmitted in each of a plurality of beams formed by the base station device 101. The report setting unit 902 notifies the terminal device 111 of the radio resource settings. The communication processing unit 903 performs communication processing with the terminal device 111. For example, the communication processing unit 903 transmits a downlink signal (PDSCH) to the terminal device 111 and performs processing to receive a HARQ-ACK for the PDSCH. The communication processing unit 903 performs communication processing, for example, to transmit a control signal, such as a DM-RS, along with the PDSCH. Furthermore, the communication processing unit 903 executes communication processing to allocate radio resources to the terminal device 111 for transmitting an uplink signal (PUSCH) and receive a radio signal from the terminal device 111 via the radio resources. The report receiving unit 904 receives measurement result information from the terminal device 111. For example, the report receiving unit 904 receives the measurement results in pre-configured radio resources for reporting SSB or CSI-RS measurement results. Furthermore, when the terminal device 111 is able to use uplink radio resources corresponding to a timing earlier than the pre-configured radio resources, the report receiving unit 904 can monitor the radio resources and determine whether a measurement result report from the terminal device 111 has arrived. For example, when a PDSCH is transmitted to the terminal device 111, and the report receiving unit 904 determines that a HARQ-ACK for the PDSCH is transmitted at a timing earlier than the pre-configured radio resources, the report receiving unit 904 can monitor whether a measurement report has been multiplexed onto the HARQ-ACK and received. When the measurement report is multiplexed into the HARQ-ACK, the report receiving unit 904 performs demultiplexing processing to separate and acquire the measurement report and the HARQ-ACK information.Furthermore, when the report receiving unit 904 determines that a radio resource for transmitting a PUSCH has been allocated to the terminal device 111 at a timing earlier than the preset radio resource, the report receiving unit 904 can determine whether a measurement report has been received in that radio resource. For example, when a MAC CE for a measurement report is received in the radio resource for the PUSCH, the report receiving unit 904 can receive the measurement report by decoding the MAC CE. The beam setting unit 905 performs setting processing such as selecting a beam that can be used with the terminal device 111 based on the measurement result of the radio quality in the terminal device 111 received by the report receiving unit 904.

[0030] FIG. 10 is a diagram illustrating an example of the functional configuration of a terminal device 111 according to this embodiment. The terminal device 111 includes, for example, a measurement unit 1001 and a measurement result reporting unit 1002 as its functions. Note that FIG. 10 only illustrates functions particularly related to this embodiment, and various other functions that the terminal device 111 may have are omitted from the illustration. For example, the terminal device 111 naturally has other functions that terminal devices compliant with 5G or subsequent standards generally have. The functional blocks in FIG. 10 are illustrated schematically, and each functional block may be integrated or further subdivided. Each function in FIG. 10 may be realized, for example, by the processor 801 executing a program stored in the ROM 802 or the storage device 804, or by a processor within the communication circuit 805 executing predetermined software. Since the details of the processing performed by each functional unit have been described above, the description will not be repeated here, and only the general functions will be outlined.

[0031] The measurement unit 1001 performs radio quality measurement based on a reference signal transmitted from the base station device 101. For example, in response to receiving a measurement instruction, the measurement unit 1001 measures the reception quality (e.g., RSRP or RSRQ) of SSB or CSI-RS transmitted in at least some of the multiple beams formed by the base station device 101. Furthermore, in one embodiment, when the measurement unit 1001 receives a downlink signal in a beam in which the measurement of the reception quality of SSB or CSI-RS has been performed before reporting the measurement result, the measurement unit 1001 may measure the reception quality of the downlink signal. The measurement result reporting unit 1002 reports the radio quality measured by the measurement unit 1001 to the base station device 101. For example, the measurement result reporting unit 1002 may transmit a signal reporting the measurement result in a radio resource for reporting preset by the base station device 101. Furthermore, if a second radio resource available for transmitting an uplink signal exists at a timing earlier than the preset first radio resource for reporting, the measurement result reporting unit 1002 may transmit a measurement result report using the second radio resource. The method for reporting the measurement result using the second radio resource is as described above, and therefore the description will not be repeated here. The measurement result reporting unit 1002 may transmit a portion of the measurement result using the second radio resource and transmit the remaining portion using the first radio resource or a third radio resource different from the first and second radio resources. In one example, the measurement result reporting unit 1002 multiplexes the measurement result with a HARQ-ACK, which is a response to the reception of the PDSCH, at a timing earlier than the preset radio resource. The measurement result reporting unit 1002 may also report the remaining portion of the measurement result using a radio resource for the PUSCH, which is similarly assigned at a timing earlier than the preset radio resource. For example, if the measurement result reporting unit 1002 is able to report all measurement results at a timing earlier than the preset radio resource, the measurement result reporting unit 1002 may not need to use the preset radio resource.Furthermore, for example, if measurement section 1001 performs a second measurement of the radio quality of DM-RS or the like after performing a first measurement of the radio quality of SSB or CSI-RS and before reporting the measurement, measurement result reporting section 1002 may report only the result of the second measurement and not the result of the first measurement. Furthermore, measurement result reporting section 1002 may report both the result of the second measurement and the result of the first measurement to base station apparatus 101.

[0032] With the above configuration, it is possible to reduce the time from when the terminal device 111 measures a signal from the base station device 101 to when it reports the results of that measurement. As a result, it is possible for the base station device 101 to more appropriately select a beam to be used for communication with the terminal device 111. This makes it possible to contribute to Goal 9 of the United Nations-led Sustainable Development Goals (SDGs), which is to "Develop resilient infrastructure, promote sustainable industrialization, and foster innovation."

[0033] The invention is not limited to the above-described embodiment, and various modifications and variations are possible within the scope of the gist of the invention.

[0034] This application claims priority based on Japanese Patent Application No. 2023-167841, filed on September 28, 2023, the entire contents of which are incorporated herein by reference.

Claims

1. A terminal device comprising: a measurement means for performing a first measurement of a predetermined signal for selecting a beam to be used in communication with the terminal device, the predetermined signal being transmitted by a base station device at a first timing; and performing a second measurement based on the signal when the base station device receives a signal transmitted by the same beam as the predetermined signal at a third timing between the first timing and a second timing corresponding to a radio resource used to report the result of the first measurement; and a transmission means for transmitting the result of the second measurement to the base station device instead of the result of the first measurement when the second measurement has been performed, and for transmitting the result of the first measurement to the base station device when the second measurement has not been performed.

2. The terminal device according to claim 1, wherein the measurement means, in the second measurement, measures a demodulation reference signal (DM-RS) transmitted from the base station device together with a physical downlink shared channel (PDSCH).

3. The terminal device according to claim 1, wherein the measurement means measures at least one of an SSB (Synchronization Signal / Physical Broadcast Channel (SS / PBCH) Block) and a CSI-RS (Channel State Information-Reference Signal) transmitted from the base station device in the first measurement.

4. The terminal device of claim 1, wherein the transmitting means transmits at least a portion of the results of the first measurement or the second measurement using other radio resources based on the fact that other radio resources can be used to transmit information other than the results of the first measurement and the second measurement to the base station device between the third timing and the second timing.

5. The terminal device according to claim 4, wherein the transmitting means multiplexes at least a portion of the result of the first measurement or the second measurement with a composite automatic repeat request acknowledgement (HARQ-ACK) for a physical downlink shared channel (PDSCH) received from the base station device, and transmits the multiplexed result in the other radio resources available for transmitting the HARQ-ACK.

6. The terminal device according to claim 5, wherein the transmitting means performs multiplexing by modulating the HARQ-ACK using at least a portion of the result of the first measurement or the second measurement.

7. The terminal device of claim 5, wherein the transmitting means transmits a portion of the result of the first measurement or the second measurement in the other radio resource usable for transmitting the HARQ-ACK, and transmits a remaining portion of the result of the first measurement or the second measurement in a radio resource at a later timing than the other radio resource.

8. The terminal device according to claim 4, wherein the transmitting means transmits at least a part of the result of the first measurement or the second measurement using a medium access control element (MAC CE) in the other radio resources allocated by the base station device for the transmission of a physical uplink shared channel (PUSCH) by the terminal device.

9. A control method executed by a terminal device, comprising: performing a first measurement of a predetermined signal for selecting a beam to be used in communication with the terminal device, the predetermined signal being transmitted by a base station device at a first timing; performing a second measurement based on the predetermined signal when the base station device receives a signal transmitted by the same beam as the predetermined signal at a third timing between the first timing and a second timing corresponding to a radio resource used to report the result of the first measurement; transmitting the result of the second measurement to the base station device instead of the result of the first measurement when the second measurement has been performed, and transmitting the result of the first measurement to the base station device when the second measurement has not been performed.

10. A program for causing a computer installed in a terminal device to execute the control method according to claim 9.

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