Terminal, base station, and wireless communication system

Abstract

This terminal includes a reception unit and a control unit. The reception unit receives, from the base station, a first signal including first information indicating that Cell DTX (Discontinuous Transmission) is enabled that includes an active section and an inactive section. Depending on whether the inactive section of the Cell DTX overlaps a preconfigured resource for receiving a signal from the base station, the control unit controls whether to generate feedback information for the preconfigured resource.

Description

Terminal, base station, and wireless communication system

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

[0002] In the standardization project 3GPP (3rd Generation Partnership project (registered trademark)), NR (New Radio (also referred to as "5G")), which is the fifth generation mobile communication, eMBB (Enhanced Mobile Broadband), Massive MTC (Machine Type Communications), and URLLC (Ultra-Reliable and Low Latency Communications) Technical specifications for communication standards that satisfy the requirements have been formulated (Non-Patent Documents 1 to 13).

[0003] 3GPP employs a hybrid automatic repeat request (HARQ) technique to achieve efficient data transmission. In HARQ, a receiving device requests a transmitting device to retransmit data that could not be correctly decoded in processing at the Layer 1 protocol layer, for example. When a data retransmission request is received, the transmitting device transmits retransmission data corresponding to the retransmission request for the original data that could not be correctly decoded at the receiving device. The receiving device combines the data that could not be correctly decoded with the retransmitted data to decode the data. This achieves highly efficient and highly accurate retransmission control. In addition, in the hybrid automatic repeat request, if the receiving device correctly decodes the data, it transmits ACK (acknowledgement) information, and if the receiving device cannot correctly decode the data, it transmits NACK (negative-acknowledgement) information.

[0004] Furthermore, in 3GPP, NES (Network Energy Savings) technology is being studied to reduce power consumption on the network side (i.e., base station devices, core network devices) (Non-Patent Document 14).

[0005] As one of the technologies for NES, Cell DTX / DRX is being studied to realize discontinuous reception (DRX) and / or discontinuous transmission (DTX) on a cell-by-cell basis. Cell DTX / DRX is a technology in which a base station device sets an active period and an inactive period (or non-active period) on a cell-by-cell basis, and the base station device performs normal transmission and reception only during the active period and restricts transmission and reception during the inactive period, thereby reducing power consumption (Non-Patent Documents 14 to 16).

[0006] It has been agreed that Cell DTX / DRX will be activated using a signal in the Radio Resource Control (RRC) layer or a Physical Downlink Control Channel (PDCCH), which is a downlink control channel (Non-Patent Documents 15 and 16).

[0007] 3GPP TS 38.133 V17.10.03GPP TS 38.201 V17.0.03GPP TS 38.202 V17.3.03GPP TS 38.211 V17.5.03GPP TS 38.212 V17.5.03GPP TS 38.213 V17.6.03GPP TS 38.214 V17.6.03GPP TS 38.215 V17.3.03GPP TS 38.300 V17.5.03GPP TS 38.321 V17.5.03GPP TS 38.322 V17.3.03GPP TS 38.323 V17.5.03GPP TS 38.331 V17.5.03GPP TR 38.864 V18.1.0R2-2306553R1-2306262

[0008] Semi-persistent scheduling (SPS) is a method in which a terminal is configured with resources for receiving signals from a base station in advance and receives signals using the configured resources.

[0009] However, while there may be a situation where Cell DTX / DRX processing and communication using a pre-defined resource such as SPS are performed simultaneously, the details of the processing for such a situation have not been determined, and therefore there is a possibility that Cell DTX / DRX processing is not efficient across the entire wireless communication system.

[0010] In this way, the processing related to Cell DTX / DRX needs to take into consideration a situation in which the processing of Cell DTX / DRX and communication using a pre-configured resource such as SPS are performed simultaneously. Note that the processing related to Cell DTX / DRX includes signal processing including transmission and reception of HARQ feedback information during the period in which Cell DTX / DRX is performed.

[0011] The disclosed technology has been made in view of the above, and aims to provide a method that enables efficient processing related to Cell DTX / DRX.

[0012] In one aspect, a terminal is provided that includes: a receiving unit that receives a first signal including first information indicating that Cell DTX (Discontinuous Transmission) is enabled from a base station; and a control unit that controls whether to generate feedback information for resources depending on whether an inactive interval of Cell DTX and resources preset for receiving signals from the base station overlap.

[0013] It is possible to provide a terminal, a base station, a wireless communication system, etc. that can efficiently perform processing related to Cell DTX / DRX.

[0014] FIG. 1 is a diagram illustrating an example of a wireless communication system according to a first embodiment. FIG. 2 is a diagram illustrating an example of a functional configuration of a base station. FIG. 3 is a diagram illustrating an example of a functional configuration of a terminal. FIG. 4 is a diagram illustrating an example of a processing sequence of the wireless communication system according to the first embodiment. FIG. 5 is a diagram illustrating an example of processing in a terminal according to the first embodiment. FIG. 6 is a diagram illustrating an example of the relationship between resources set in resource allocation information and active and inactive periods of Cell DTX. FIG. 7 is a diagram illustrating an example of a specification reflecting the processing of the first embodiment. FIG. 8 is a diagram illustrating an example of processing in a terminal according to the second embodiment. FIG. 9 is a diagram illustrating an example of a specification reflecting the processing of the second embodiment. FIG. 10 is a diagram illustrating an example of resources allocated for a base station to transmit a signal. FIG. 11 is a diagram illustrating an example of a specification reflecting the processing of the third embodiment. FIG. 12 is a diagram illustrating an example of a specification reflecting the processing of the third embodiment. FIG. 13 is a diagram illustrating an example of a hardware configuration of a base station in the wireless communication system. FIG. 14 is a diagram illustrating an example of a hardware configuration of a terminal in the wireless communication system.

[0015] The present embodiment will be described in detail below with reference to the drawings. The problems and embodiments in this specification are merely examples and do not limit the scope of the rights of the present application. In particular, even if the expressions used are different, the technology of the present application can be applied as long as they are technically equivalent, and do not limit the scope of the rights. Furthermore, each embodiment can be combined as appropriate within the scope of not causing any contradiction in the processing content.

[0016] Furthermore, the terms used and technical contents described in this specification may be those described in specifications and contributions as standards related to communications, such as 3GPP, as appropriate. Examples of such specifications include those described in Non-Patent Documents 1 to 14.

[0017] Hereinafter, embodiments of a base station, a terminal, and a wireless communication system disclosed in the present application will be described in detail with reference to the accompanying drawings. Note that the disclosed technology is not limited to the following embodiments.

[0018] [Problem] Before describing each embodiment, the problem in the prior art will be described. Please note that this problem was newly discovered by the inventors as a result of careful consideration of the prior art, and was not previously known.

[0019] In a PDSCH (Physical Downlink Shared CHannel) (hereinafter, sometimes referred to as SPS-PDSCH) using SPS (semi-persistent scheduling), if a terminal cannot receive the SPS-PDSCH from a base station using pre-configured resources for transmitting the PDSCH, the terminal generates a NACK as HARQ feedback information. Then, the terminal transmits the generated NACK to the base station as HARQ feedback information.

[0020] Furthermore, during the inactive period of Cell DTX, the base station does not transmit a signal in the cell during the inactive period. Therefore, for example, if the inactive period of Cell DTX overlaps with the resource preset for transmitting the SPS-PDSCH, the base station does not transmit a signal (SPS-PDSCH) using the resource preset for transmitting the SPS-PDSCH.

[0021] On the other hand, since the base station does not transmit the SPS-PDSCH, the terminal cannot receive the SPS-PDSCH from the base station using the resources preset for transmitting the SPS-PDSCH. Therefore, the terminal generates a NACK and transmits the generated NACK as HARQ feedback information.

[0022] Here, during the inactive period of Cell DTX, the base station and the terminal may mutually recognize that the base station will not transmit the SPS-PDSCH, but the generated NACK will be transmitted as HARQ feedback information. As a result, resource utilization efficiency may decrease. In addition, since the terminal side performs processing to generate and transmit HARQ feedback information, and the base station side performs processing associated with receiving the HARQ feedback information, this also affects the power consumption of both the terminal and the base station.

[0023] Although the above description is given using an example in which a downlink signal is transmitted from a base station to a terminal and HARQ feedback information for the downlink signal is transmitted from the terminal to the base station, the same thing may occur when an uplink signal is transmitted from the terminal to the base station and HARQ feedback information for the uplink signal is transmitted from the base station to the terminal.

[0024] To summarize the above, for example, if a Cell DTX / DRX inactive period overlaps with a resource preset for transmitting a signal, a situation may arise in which excessive power consumption occurs. Therefore, processing related to Cell DTX / DRX is required that takes into account the relationship between the Cell DTX / DRX inactive period and the resource preset for transmitting a signal. As described above, this problem was newly discovered by the inventors as a result of careful consideration of the prior art, and was not previously known. Below, each embodiment of the present application that solves this problem will be described in order. First Embodiment

[0025] FIG. 1 is a diagram showing an example of a wireless communication system 1 according to the first embodiment. The wireless communication system 1 includes a base station 100, a terminal 200A, and a terminal 200B. The base station 100 forms a cell C10. When there is no need to distinguish between the terminal 200A and the terminal 200B, they will be simply referred to as terminal 200. The terminal 200 is located within the cell C10.

[0026] The base station 100 may be, for example, a small wireless base station such as a macro wireless base station or a pico wireless base station (including a micro wireless base station, a femto wireless base station, etc.), or may be a wireless base station of various scales, and may be referred to as a wireless communication device, a communication device, a transmitting device, etc. The terminal 200 may be, for example, a wireless terminal such as various devices having a wireless communication function, such as a mobile phone, a smartphone, a PDA (Personal Digital Assistant), a personal computer, a vehicle, an airplane, a drone, or a device (sensor device, etc.) mounted on a robot, AV equipment, home appliances, office equipment, vending machines, other household equipment, industrial equipment, etc., and may be referred to as a wireless communication device, a communication device, a receiving device, a mobile station, etc.

[0027] The base station 100 is connected to a network device (a higher-level device or another base station) not shown in the figure via a wired connection. Note that the base station 100 may be connected to the network device wirelessly instead of via a wired connection.

[0028] The base station 100 may be configured such that the wireless communication function with the terminal 200 and the digital signal processing and control functions are separated into separate devices. In this case, the device having the wireless communication function can be called an RRH (Remote Radio Head), and the device having the digital signal processing and control functions can be called a BBU (Base Band Unit). The RRHs may be installed extending from the BBU, and they may be connected by a wired connection such as optical fiber. Alternatively, they may be connected wirelessly. Instead of the aforementioned RRH and BBU, the base station 100 may be separated into, for example, a CU (Central Unit), a DU (Distributed Unit), and an RU (Radio Unit). The DU includes, for example, a MAC (Media Access Control) layer function. The DU may also include, for example, a function of an RLC (Radio Link Control) layer. The RU includes at least an RF (Radio Frequency) wireless circuit. The DU and RU may also be integrated into one unit.

[0029] On the other hand, the terminal 200 communicates with the base station 100 via wireless communication.

[0030] If a Radio Resource Control (RRC) connection has not been established between base station 100 and terminal 200, base station 100 performs processing to establish an RRC connection.

[0031] Next, the base station 100 will be described. Fig. 2 is a diagram showing an example of a functional configuration diagram of the base station 100. The base station 100 has a wireless communication unit 110, a control unit 120, a storage unit 130, and a communication unit 140.

[0032] The wireless communication unit 110 is composed of a transmitting unit 111 and a receiving unit 112, and performs wireless communication with the terminal 200. Specifically, the transmitting unit 111 transmits to the terminal 200 downlink signals such as a random access procedure signal, an RRC layer signal, a downlink data signal, and a downlink control signal.

[0033] Furthermore, the receiving unit 112 can receive uplink signals transmitted from the terminal 200, such as signals of a random access procedure, signals of an RRC layer, uplink data signals, and uplink control signals.

[0034] The control unit 120 controls the base station 100. Specifically, the control unit 120 can control the establishment of an RRC connection with the terminal 200, signal processing of signals received by the receiving unit 112, creation of transmission blocks (TBs), mapping of the transmission blocks to radio resources, and the like.

[0035] The storage unit 130 can store, for example, downstream data signals.

[0036] The communication unit 140 connects to and communicates with a network device (e.g., a higher-level device or another base station device) via a wired or wireless connection. The data signal received by the communication unit 140 and intended for the terminal 200 can be stored in the storage unit 130.

[0037] Next, the terminal 200 will be described. Fig. 3 is a diagram showing an example of a functional configuration diagram of the terminal 200. As shown in Fig. 3, the terminal 200 includes a communication unit 210, a control unit 220, and a storage unit 230. These components are connected to each other so as to enable unidirectional or bidirectional input and output of signals and data. The communication unit 210 can be described as being divided into a transmission unit 211 and a reception unit 212.

[0038] The transmitter 211 transmits data signals and control signals by wireless communication via an antenna. Note that the antenna may be common for both transmission and reception. The transmitter 211 transmits uplink signals such as random access procedure signals, RRC layer signals, uplink data signals, and uplink control signals, for example.

[0039] The receiver 212 receives downlink signals such as a random access procedure signal, a downlink data signal, a downlink control signal, etc. transmitted from the base station 100. The received signals may also include reference signals used for channel estimation and demodulation, for example.

[0040] The control unit 220 controls the terminal 200. Specifically, the control unit 220 can control the establishment of an RRC connection with the base station 100, signal processing of signals received by the receiving unit 212, creation of transmission blocks (TBs), mapping of the transmission blocks to radio resources, and the like.

[0041] The storage unit 230 can store, for example, uplink data signals, and can also store configuration information (or setting information) related to wireless communication transmitted from the base station 100.

[0042] Next, processing by the base station 100 and the terminal 200 in the wireless communication system 1 according to the first embodiment will be described using Fig. 4 . Fig. 4 is a diagram showing an example of a processing sequence of the wireless communication system 1 according to the first embodiment. Note that in Fig. 4 , the terminal 200A is a terminal in which resources for downlink signals are configured in advance, and the terminal 200B is a terminal in which resources for downlink signals are not configured in advance. Note that in Fig. 4 , it is assumed that Cell DTX is configured in advance. Note that the Cell DTX configuration is configured in the terminal 200, for example, using a signal in the RRC layer before the sequence shown in Fig. 4 . Note that the Cell DTX configuration is configured using a signal that transmits the same information within the same cell C10, such as an MIB (Material Information Block) or SIB1 (System Information Block 1).

[0043] The transmitter 111 of the base station 100 transmits a signal including resource allocation information to the terminal 200A (step S10). The signal including the resource allocation information is, for example, a second signal. The second signal is, for example, a signal of the RRC layer. The resource allocation information is an example of the second information.

[0044] When receiving a signal including resource allocation information from base station 100 (step S10), receiving unit 212 of terminal 200A sets a configuration according to the resource allocation information. Then, when setting of the configuration according to the resource allocation information to base station 100 is completed, transmitting unit 211 of terminal 200A transmits a response signal to the signal including the resource allocation information. The configuration according to the resource allocation information will be described later.

[0045] The transmitter 111 of the base station 100 transmits a signal including information for validating resources set in the resource allocation information (step S30). The signal including information for validating resources set in the resource allocation information is an example of a third signal. The third signal is, for example, a PDCCH (Physical Downlink Control Channel). The information for validating resources set in the resource allocation information is also an example of the third information. When the controller 220 of the terminal 200A receives the signal including information for validating resources set in the resource allocation information, the controller 220 controls the receiver 220 to receive downlink signals using resources according to the resource allocation information.

[0046] Next, the transmitter 111 of the base station 100 transmits a signal including information indicating that Cell DTX is to be enabled to the terminals 200A and 200B in the cell C10 (step S40). The signal including the information indicating that Cell DTX is to be enabled is an example of a first signal. The first signal is, for example, a physical layer signal (e.g., PDCCH) or an RRC layer signal that can be transmitted to multiple terminals 200. The information indicating that Cell DTX is to be enabled is an example of first information. Then, when Cell DRX is enabled, the base station 100 performs a first process in the cell C10, which is a process corresponding to Cell DTX (step S50). The first process is, for example, a process of transmitting a signal to the terminal 200 in the cell C10 during an active period (Active period), and not transmitting a signal to the terminal 200 in the cell C10 during an inactive period (Inactive period or Non-active period).

[0047] Furthermore, when Cell DTX is enabled, terminal 200B performs a third process that is a process according to Cell DTX (step S70). Specifically, for example, terminal 200B performs control to monitor signals via cell C10 during the active period of Cell DTX, and performs control not to monitor signals via cell C10 during the inactive period.

[0048] Furthermore, when Cell DTX is enabled, terminal 200A performs a second process that is a process corresponding to Cell DTX (step S60). Specifically, in addition to the third process, terminal 200A performs a process of controlling whether to generate feedback information for overlapping resources depending on whether the inactive period and the resources set in the enabled resource allocation information overlap. Specifically, for example, when the inactive period and the resources set in the enabled resource allocation information overlap, terminal 200A does not generate feedback information for the overlapping resources.

[0049] Here, an example of the second process that differs from the third process will be described with reference to Fig. 5 and Fig. 6. Fig. 5 is a diagram showing an example of an operation flow in terminal 200A. Fig. 6 is a diagram showing an example of the relationship between resources set in resource allocation information and active and inactive periods of Cell DTX.

[0050] The control unit 220 of the terminal 200A enables Cell DTX for the cell C10 (step S61). The control unit 220 of the terminal 200A determines whether the current interval is an inactive interval (step S62).

[0051] For example, as shown in FIG. 6 , among the time intervals A1 to A10, the active intervals of Cell DTX are time intervals A1 to A4, and the inactive intervals of Cell DTX are time intervals A5 to A10. Furthermore, the time intervals A1 to A10 are an example of a configuration according to resource allocation information, and among the time intervals A1 to A10, time intervals A3, A6, and A9 indicate resources pre-allocated for signal transmission. The time interval is, for example, any unit on the time axis, such as a slot, a subframe, or a frame. Then, in step S62, for example, in the case of the time intervals A1 to A4, the current interval is determined to be an active interval, and in the case of the time intervals A5 to A10, the current interval is determined to be an inactive interval. The signal transmitted using the pre-allocated resources is, for example, SPS-PDSCH.

[0052] If the time interval is an active interval (step S62: No), the control unit 220 of the terminal 200A performs a signal reception process using the set resource. For example, the control unit 220 controls the receiving unit 212 to receive a signal from the base station 100 during the time interval A3 in FIG. 6 .

[0053] Then, control unit 220 of terminal 200A generates HARQ feedback information according to the result of the reception processing, and transmits the generated HARQ feedback information (step S64). For example, when data decoding is successful, control unit 220 of terminal 200A generates ACK as HARQ feedback information, and when data cannot be received or when data decoding fails, generates NACK as HARQ feedback information. Note that HARQ feedback information is an example of feedback information.

[0054] If the time interval is an inactive interval (step S62: Yes), control unit 220 of terminal 200A controls so as not to perform signal reception processing using the configured resources. For example, control unit 220 controls so as not to cause receiver 212 to receive signals from base station 100 during time intervals A6 and A9 in Fig. 6 . Furthermore, in step S65, since reception processing is not performed, control unit 220 controls so as not to generate HARQ feedback information associated with the reception processing.

[0055] As described above, in the first embodiment, when a Cell DTX inactivation interval overlaps with a configured resource, terminal 200 does not transmit HARQ feedback information for the resource. Therefore, terminal 200 does not generate or transmit HARQ feedback information, which can reduce, for example, power consumption in terminal 200. Furthermore, when a Cell DTX inactivation interval overlaps with a configured resource, base station 100 does not receive HARQ feedback information for the resource. Therefore, base station 100 does not perform processing associated with receiving HARQ feedback information, which can reduce, for example, power consumption in base station 100. In other words, it is possible to efficiently perform processing related to Cell DTX / DRX.

[0056] It should be noted that the first embodiment can be reflected in the specifications, for example, as shown in Figure 7. Figure 7(A) is a diagram showing an example in which the processing of the first embodiment is reflected in the specifications (TS38.213). For example, Figure 7(A) is a first example in which the processing of the first embodiment is reflected in the specifications (TS38.213), and Figure 7(B) is a second example in which the processing of the first embodiment is reflected in the specifications (TS38.213). The difference between the first example and the second example is whether or not there is a description regarding the PDCCH, which corresponds to the third signal in Figure 4. Embodiment 2

[0057] In the first embodiment, an example has been described in which terminal 100 controls not to generate HARQ feedback information when the inactive interval of Cell DTX overlaps with the configured resource. In the second embodiment, control will be described in which it is determined whether or not to generate HARQ feedback information in accordance with the third signal described in the first embodiment. Note that in the second embodiment, the radio communication system, the base station, and the terminal are the same as those in the first embodiment, and therefore description thereof will be omitted.

[0058] Fig. 8 is a diagram showing an example of an operation flow in terminal 200A in embodiment 2. Fig. 8 is a diagram showing an example of processing in the terminal in embodiment 2. Note that Fig. 8 shows processing included in the second processing shown in Fig. 4, and explanations of parts that overlap with Fig. 5 will be omitted.

[0059] If the time interval is an inactive interval (step S62: Yes), the control unit 220 of the terminal 200A determines whether the signal received in step S40 is a specific type of signal (step S66). Note that the specific type of signal is, for example, a signal of the RRC layer. Also, for example, a signal different from the specific type of signal is, for example, a PDCCH.

[0060] If the signal is a specific type of signal (step S66: Yes), the process of step S65 is performed. If the signal is not a specific type of signal (step S66: No), the processes of steps S63 and S64 are performed. Note that if the process of step S63 is performed via step S66, for example, no signal is received in time interval A6, and therefore, in the process of step S64, a NACK is generated as the HARQ feedback information.

[0061] As described above, in the second embodiment, when the Cell DTX inactivation interval overlaps with the configured resources, the terminal 200 controls whether to generate and transmit HARQ feedback depending on the type of signal that enables Cell DTX. This control allows control not to generate and transmit HARQ feedback for a specific type of signal. On the other hand, for signals other than the specific type of signal, conventional control can be performed. For example, when the signal that enables Cell DTX is an RRC layer signal, control is performed not to generate and transmit HARQ feedback. This makes it possible to control not to perform processing associated with reception of HARQ feedback information in the base station 100, thereby reducing power consumption in the terminal 200 and the base station 100, for example. In other words, it becomes possible to efficiently perform processing related to Cell DTX / DRX. For example, when the signal for enabling Cell DTX is a physical layer signal (e.g., PDCCH), the HARQ feedback generation and transmission is controlled in consideration of the possibility that the terminal may fail to receive the physical layer signal for enabling or disabling Cell DTX, thereby avoiding the terminal being unable to respond to the transmission from the base station and the HARQ feedback information when it fails to receive the physical layer signal for disabling Cell DTX.

[0062] The second embodiment can be reflected in the specifications, for example, as shown in Fig. 9. Fig. 9 is a diagram showing an example in which the processing of the second embodiment is reflected in the specifications (TS38.213). Embodiment 3

[0063] In the first embodiment, an example has been described in which terminal 100 controls not to generate HARQ feedback information when the inactive interval of Cell DTX overlaps with the configured resource. In the second embodiment, control has been described in which it is determined whether or not to generate HARQ feedback information in accordance with a third signal. In the third embodiment, an example will be described in which a HARQ-ACK codebook is used as HARQ feedback information. Note that the wireless communication system, base station, and terminal are the same as those in the first embodiment, and therefore description thereof will be omitted.

[0064] The HARQ-ACK codebook will now be described. The HARQ-ACK codebook is a method of multiplexing ACK / NACK information from multiple slots or multiple carriers into one signal (e.g., in a PUCCH or PUSCH) and transmitting it as HARQ feedback information. There are, for example, three types of HARQ-ACK codebooks.

[0065] The first type of HARQ-ACK codebook is a semi-static method, which generates HARQ ACK / NACK for a downlink signal reception position set based on an RRC signal, for example.

[0066] The second type of HARQ-ACK codebook is a dynamic method, which generates HARQ ACK / NACK only for downlink signals that are actually scheduled in downlink control information and actually transmitted from the base station.

[0067] The third type of HARQ-ACK codebook is a one-shot method, in which downlink control information triggers HARQ feedback for all configured cells (or serving cells) or a subset of configured cells (or serving cells) and / or HARQ processes.

[0068] <HARQ Feedback Using First Type HARQ-ACK Codebook> HARQ feedback using the first type HARQ-ACK codebook performed by terminal 200 in embodiment 3 will be described with reference to Fig. 10. Fig. 10 is a diagram showing an example of resources allocated for a base station to transmit a signal.

[0069] As shown in FIG. 10 , it is assumed that base station 100 has configured cells A, B, and C for terminal 200. Cell B is, for example, cell C10. Here, it is assumed that SPS-PDSCH resources are configured for cell B. Cell DTX is enabled for cell B. Cell A has time intervals B1-B6 formed from interval n to interval n+5, with time interval B3 indicating the location of resources preset for transmitting downlink signals. Time interval B6 indicates the time interval in which the terminal transmits HARQ feedback. Cell B has time intervals C1-C6 formed from interval n to interval n+5, with time interval C2 indicating the location of resources preset for transmitting downlink signals. Cell C has time intervals D1-D6 formed from interval n to interval n+5, with time interval D4 indicating the location of resources preset for transmitting downlink signals.

[0070] In the case of Fig. 10, terminal 200 uses, for example, the method described in embodiment 1 for cell B. That is, since time intervals C1-C6 are inactive intervals for cell B, terminal 200 does not perform processing to generate HARQ feedback for time interval C2. Therefore, the HARQ feedback information transmitted from terminal 200 in time interval B6 includes ACK / NACK information corresponding to the reception processing in time interval B3 and ACK / NACK information corresponding to the reception processing in time interval D4.

[0071] Terminal 200 may generate HARQ feedback only for the SPS-PDSCH. In this case, HARQ feedback is not generated for configured SPS-PDSCH resources that overlap with the Cell DTX inactivation interval. For example, terminal 200 does not perform processing to generate HARQ feedback for time interval C2. Therefore, the HARQ feedback information transmitted from terminal 200 in time interval B6 includes ACK / NACK information corresponding to the reception processing in time interval B3 and ACK / NACK information corresponding to the reception processing in time interval D4.

[0072] Note that in cell B of FIG. 10 , HARQ feedback may be generated using the method of embodiment 2. In short, terminal 200 controls whether to generate ACK or NACK information for resources in time interval C2 depending on the type of signal including information for enabling Cell DTX. For example, if the signal for enabling Cell DTX is an RRC layer signal, control is performed so that HARQ feedback is not generated and transmitted. For example, if the signal for enabling Cell DTX is a physical layer signal (e.g., PDCCH), control is performed so that HARQ feedback is generated and transmitted. Note that if ACK or NACK information for resources in time interval C2 is generated, terminal 200 transmits HARQ feedback information including, for example, three pieces of ACK or NACK information.

[0073] Terminal 200 may generate HARQ feedback only for the SPS-PDSCH. In this case, terminal 200 controls whether to generate ACK or NACK information for configured SPS-PDSCH resources that overlap with the Cell DTX inactivation interval, depending on the type of signal including information for enabling Cell DTX. For example, if the signal for enabling Cell DTX is an RRC layer signal, terminal 200 does not perform processing to generate HARQ feedback for time interval C2. For example, if the signal for enabling Cell DTX is a physical layer signal (e.g., PDCCH), terminal 200 controls to generate and transmit HARQ feedback. Terminal 200 performs processing to generate HARQ feedback for time interval C2. Therefore, in time interval B6, the HARQ feedback information transmitted from terminal 200 includes ACK / NACK information corresponding to the receiving processing in time interval B3, ACK / NACK information corresponding to the receiving processing in time interval C2, and ACK / NACK information corresponding to the receiving processing in time interval D4.

[0074] Terminal 200 may generate HARQ feedback only for retransmission signals. For example, in FIG. 10, terminal 200 assumes that time intervals B3 and C2 are resources for transmitting retransmission signals, and time interval D4 is a resource preset for transmitting downlink signals. Note that cell B is an inactive interval, but base station 100 can transmit signals in response to retransmission signals. Therefore, it is possible to receive the retransmitted signal in time interval C2.

[0075] In this case, the HARQ feedback information transmitted from terminal 200 in time interval B6 will include ACK or NACK information corresponding to the receiving processing in time interval B3 and ACK or NACK information corresponding to the receiving processing in time interval C2.

[0076] The HARQ feedback information transmitted from terminal 200 may include ACK or NACK information for signals excluding retransmission signals performed in the inactive period in cell B. In short, terminal 200 generates ACK or NACK for signals received in cell A and cell C, and controls cell B to generate ACK or NACK depending on the type of signal to be received (whether it is a retransmission signal or not).

[0077] Note that the HARQ feedback using the first type HARQ-ACK codebook in the third embodiment can be reflected in the specifications by being as shown in Figure 11. Note that Figure 11 is a diagram showing an example in which the processing of the third embodiment is reflected in the specifications (TS38.213). For example, Figure 11 (A) specifies in the specifications (TS38.213) that when HARQ feedback is generated only for the SPS-PDSCH, HARQ feedback information (e.g., ACK or NACK) is not generated for the SPS-PDSCH in the active interval. Also, Figure 11 (B) is an example in which the specifications (TS38.213) specify that when control information indicates a retransmission, HARQ report information is generated only for the retransmission signal.

[0078] <HARQ Feedback Using Second Type HARQ-ACK Codebook> HARQ feedback using the second type HARQ-ACK codebook performed by terminal 200 in the third embodiment will be described.

[0079] The control unit 220 of the terminal 200 excludes signals (e.g., SPS-PDSCH) scheduled to be transmitted using resources in the Cell DTX inactive interval (in other words, outside the DTX active time) from the scope of HARQ feedback information, and generates HARQ feedback information generated for resources in the Cell DTX active interval and transmits it all together.

[0080] As described in the second embodiment, control unit 220 of terminal 200 may determine whether to generate HARQ feedback information for resources of the Cell DTX inactive interval, depending on the type of signal including information for enabling Cell DTX. For example, if the signal for enabling Cell DTX is an RRC layer signal, control unit 220 controls not to generate and transmit HARQ feedback. For example, if the signal for enabling Cell DTX is a physical layer signal (e.g., PDCCH), control unit 220 controls to generate and transmit HARQ feedback.

[0081] The HARQ feedback using the second type HARQ-ACK codebook in the third embodiment can be reflected in the specifications by being as shown in Fig. 12. Fig. 12 is a diagram showing an example in which the processing of the third embodiment is reflected in the specifications (TS38.213).

[0082] <HARQ Feedback Using Third Type HARQ-ACK Codebook> HARQ feedback using the third type HARQ-ACK codebook, performed by terminal 200 in the third embodiment, will be described.

[0083] The control unit 220 of the terminal 200 excludes signals (e.g., PDSCH) scheduled to be transmitted using resources in the Cell DTX inactive interval (in other words, outside the DTX active time) from the scope of HARQ information, and generates HARQ feedback information generated for resources in the Cell DTX active interval and transmits the information collectively.

[0084] As described in the second embodiment, control unit 220 of terminal 200 may determine whether to generate HARQ feedback information for resources of the Cell DTX inactive interval, depending on the type of signal including information for enabling Cell DTX. For example, if the signal for enabling Cell DTX is an RRC layer signal, control unit 220 controls not to generate and transmit HARQ feedback. For example, if the signal for enabling Cell DTX is a physical layer signal (e.g., PDCCH), control unit 220 controls to generate and transmit HARQ feedback.

[0085] As described above, terminal 200 controls generation of HARQ feedback information using the methods described in embodiment 1 and embodiment 2. Terminal 200 can then transmit only the generated HARQ feedback information as a single piece of feedback information. Furthermore, base station 100 can receive only the generated HARQ feedback information as a single piece of feedback information and recognize the signals corresponding to each piece of HARQ feedback information included in the received single piece of feedback information. Therefore, base station 100 can perform retransmission control and the like without being affected by HARQ feedback information that is not generated under the control of terminal 200.

[0086] As described above, in the third embodiment, terminal 200 can use the methods described in the first and second embodiments even when integrating multiple pieces of HARQ feedback information into a single piece of feedback information and transmitting it. Therefore, when a Cell DTX inactive period overlaps with a configured resource, terminal 200 controls whether to generate and transmit HARQ feedback for the resource. By controlling in this way, for example, when HARQ feedback information is not generated for the resource, it is possible to reduce the amount of information included in a single piece of feedback information. Hardware configuration of each device in each embodiment

[0087] The hardware configuration of each device in the wireless communication system of each embodiment will be described with reference to FIGS.

[0088] Fig. 13 is a diagram showing an example of the hardware configuration of base station 100. As shown in Fig. 13, base station 100 has, as hardware components, for example, an RF (Radio Frequency) circuit 320 equipped with an antenna 310, a CPU (Central Processing Unit) 330, a DSP (Digital Signal Processor) 340, a memory 350, and a network IF (Interface) 360. CPU 330 is connected via a bus so as to enable input and output of various signals and data signals. The memory 350 includes at least one of a RAM (Random Access Memory) such as an SDRAM (Synchronous Dynamic Random Access Memory), a ROM (Read Only Memory), and a flash memory, and stores programs, control information, and data signals.

[0089] The correspondence between the functional configuration of the base station 100 shown in Fig. 2 and the hardware configuration of the base station 100 shown in Fig. 13 will be described. The transmitter 111 and receiver 112 (or wireless communication unit 110) are realized by, for example, an RF circuit 320, or an antenna 310 and an RF circuit 320. The control unit 120 is realized by, for example, a CPU 330, a DSP 340, a memory 350, a digital electronic circuit (not shown), etc. Examples of the digital electronic circuit include an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), and an LSI (Large Scale Integration). The storage unit 130 is realized by, for example, the memory 350. The communication unit 140 is realized by, for example, the network IF 360 .

[0090] It should be noted that base station 100 may generate a plurality of data signals to be transmitted in a plurality of subbands, and the filters that generate these signals may be configured independently for each subband.

[0091] Fig. 14 is a diagram showing an example of the hardware configuration of terminal 200. As shown in Fig. 14, terminal 200 has, as hardware components, an RF circuit 420 including an antenna 410, a CPU 430, and a memory 440. Terminal 200 may further have a display device such as an LCD (Liquid Crystal Display) connected to CPU 430. Memory 440 includes at least one of a RAM such as an SDRAM, a ROM, and a flash memory, and stores programs, control information, and data signals.

[0092] The correspondence between the functional configuration of the terminal 200 shown in Fig. 3 and the hardware configuration of the terminal 200 shown in Fig. 14 will be described. The transmitter 211 and receiver 212 (or communication unit 210) are realized by, for example, an RF circuit 420, or an antenna 410 and an RF circuit 420. The control unit 220 is realized by, for example, a CPU 430, a memory 440, a digital electronic circuit (not shown), etc. Examples of the digital electronic circuit include an ASIC, an FPGA, and an LSI. The storage unit 230 is realized by, for example, the memory 440.

[0093] The embodiments may be combined as appropriate within a range that does not cause any contradiction.

[0094] In each embodiment, examples of a base station and a terminal are described, but the disclosed technology is not limited to this and can be applied to various devices such as electronic devices mounted on automobiles, trains, airplanes, artificial satellites, etc., electronic devices transported by drones, etc., robots, AV equipment, home appliances, office equipment, vending machines, and other household equipment.

[0095] Furthermore, although the embodiments have been described using fifth-generation mobile communications as an example, the application of the disclosed technology is not limited to this. For example, the disclosed technology may be applied to mobile communications of different generations, such as sixth and seventh generations.

[0096] 1 Wireless communication system 100 Base station C10 Cell 110 Wireless communication unit 111 Transmitter 112 Receiver 120 Control unit 130 Memory unit 140 Communication unit 200 200A 200B Terminal 210 Communication unit 211 Transmitter 212 Receiver 220 Control unit 230 Memory unit 310 Antenna 320 RF circuit 330 CPU 340 DSP 350 Memory 360 Network IF 410 Antenna 420 RF circuit 430 CPU 440 Memory

Claims

1. A terminal comprising: a receiving unit that receives a first signal including first information indicating that Cell DTX (Discontinuous Transmission) is enabled from a base station; and a control unit that controls whether or not to generate feedback information for the resources depending on whether an inactive period of the Cell DTX and resources previously set for receiving a signal from the base station overlap.

2. The terminal according to claim 1, wherein the first signal is a signal transmitted from the base station to one or more terminals within a cell, including the terminal.

3. The terminal according to claim 1, wherein the receiving unit receives a second signal including second information for setting the resources from the base station, and the control unit sets the resources in accordance with the second information.

4. The terminal according to claim 1, wherein the receiving unit receives a third signal including third information that is information for enabling the resource from the base station, and the control unit controls to enable reception of signals on the resource and perform processing on the resource in accordance with the third information.

5. The terminal according to claim 1, wherein the control unit controls so as not to generate feedback information for the overlapping resources when the first signal is a specific type of signal, and controls so as to generate feedback information for the overlapping resources when the first signal is a signal other than the specific type of signal.

6. The terminal according to claim 5, wherein the specific type of signal is a signal of an RRC layer, and the first signal is a signal different from the specific type of signal is a PDCCH.

7. The terminal according to claim 1, further comprising a transmission unit that generates the feedback information for resources excluding the overlapping resources among the resources, and transmits the feedback information.

8. A base station comprising: a transmitter that transmits a first signal including first information indicating that Cell DTX (Discontinuous Transmission) is enabled to a terminal; and a receiver that receives feedback information for the resources, the feedback information being generated depending on whether or not an inactive period of the Cell DTX overlaps with a resource that is preset for the terminal to receive a signal.

9. The base station according to claim 8, further comprising: a control unit configured to perform control so as not to perform reception processing on the feedback information for the overlapping resources.

10. A wireless communication system comprising: a base station that transmits a first signal including first information indicating that Cell DTX (Discontinuous Transmission) is enabled; and a terminal that receives the first signal and controls whether or not to generate feedback information for the resources depending on whether an inactive period of the Cell DTX overlaps with a resource that is preset for receiving a signal from the base station.

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