Terminal and communication method

Abstract

To provide a terminal and a communication method that reduce power consumption.SOLUTION: In a wireless communication system, a terminal includes a receiving unit that receives, from a base station, downlink control information that instructs both switching of a search space set or a search space set group and skipping of Physical Downlink Control Channel (PDCCH) monitoring during a specified period, and a control unit that executes at least one of switching of a search space set or a search space set group or skipping of PDCCH monitoring during a specified period on the basis of the downlink control information.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a terminal and a communication method in a wireless communication system. [Background technology]

[0002] In the 3GPP (3rd Generation Partnership Project), a wireless communication method called 5G or NR (New Radio) (hereinafter, the wireless communication method is referred to as "NR") is being studied in order to realize a larger system capacity, a higher data transmission speed, a lower latency in wireless sections, etc. In 5G, various wireless technologies and network architectures are being studied in order to meet the requirement of achieving a throughput of 10 Gbps or more while keeping the latency in wireless sections to 1 ms or less (for example, Non-Patent Document 1).

[0003] In addition, NR is considering strengthening power saving in connected mode, such as reducing PDCCH (Physical Downlink Control Channel) monitoring when connected DRX (Discontinuous reception) is set and reducing power during DCI (Downlink Control Information)-based DRX active periods. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] 3GPP TS 38.213 V16.3.0 (2020-09) [Non-Patent Document 2] 3GPP TS 38.331 V16.2.0 (2020-09) Summary of the Invention [Problem to be solved by the invention]

[0005] In order to reduce power consumption, reduction of PDCCH monitoring has been considered, but a specific method for reducing PDCCH monitoring has not been specified.

[0006] The present invention has been made in consideration of the above-mentioned points, and has an object to reduce power consumption in a wireless communication system. [Means for solving the problem]

[0007] According to the disclosed technology, a terminal includes a receiving unit that receives downlink control information from a base station that instructs both switching of a search space set or a search space set group and skipping of PDCCH (Physical Downlink Control Channel) monitoring during a specified period, and a control unit that executes at least one of switching of the search space set or the search space set group or skipping of PDCCH monitoring during the specified period based on the downlink control information. Effect of the Invention

[0008] According to the disclosed technology, a technology for reducing power consumption in a wireless communication system is provided. [Brief description of the drawings]

[0009] [Figure 1] 1 is a diagram illustrating a wireless communication system according to an embodiment of the present invention. [Diagram 2] FIG. 11 is a sequence diagram illustrating an example of monitoring according to an embodiment of the present invention. [Diagram 3] 2 is a diagram illustrating an example of a functional configuration of a base station 10 according to an embodiment of the present invention. [Figure 4] 2 is a diagram illustrating an example of a functional configuration of a terminal 20 according to an embodiment of the present invention. [Diagram 5]2 is a diagram illustrating an example of a hardware configuration of a base station 10 or a terminal 20 according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the embodiment described below is an example, and the embodiment to which the present invention is applied is not limited to the following embodiment.

[0011] In the operation of the wireless communication system according to the embodiment of the present invention, existing technologies are used as appropriate. However, the existing technologies are, for example, existing LTE, but are not limited to existing LTE. In addition, the term "LTE" used in this specification has a broad meaning including LTE-Advanced and systems after LTE-Advanced (e.g., NR) unless otherwise specified.

[0012] In the embodiment of the present invention described below, terms such as SS (Synchronization signal), PSS (Primary SS), SSS (Secondary SS), PBCH (Physical broadcast channel), PRACH (Physical random access channel), PDCCH (Physical Downlink Control Channel), PDSCH (Physical Downlink Shared Channel), PUCCH (Physical Uplink Control Channel), and PUSCH (Physical Uplink Shared Channel) used in existing LTE are used. This is for convenience of description, and similar signals, functions, etc. may be called by other names. In addition, the above-mentioned terms in NR correspond to NR-SS, NR-PSS, NR-SSS, NR-PBCH, NR-PRACH, etc. However, even if a signal is used in NR, it is not necessarily specified as "NR-".

[0013] Furthermore, in the embodiment of the present invention, the duplexing method may be a time division duplex (TDD) method, a frequency division duplex (FDD) method, or another method (for example, flexible duplex, etc.).

[0014] Furthermore, in the embodiment of the present invention, when radio parameters, etc. are "configured," this may mean that predetermined values ​​are pre-configured, or that radio parameters notified from base station 10 or terminal 20 are configured.

[0015] Fig. 1 is a diagram for explaining a wireless communication system in an embodiment of the present invention. As shown in Fig. 1, the wireless communication system in the embodiment of the present invention includes a base station 10 and a terminal 20. Although Fig. 1 shows one base station 10 and one terminal 20, this is an example, and there may be a plurality of each.

[0016] The base station 10 is a communication device that provides one or more cells and performs wireless communication with the terminal 20. The physical resources of a wireless signal are defined in a time domain and a frequency domain, and the time domain may be defined by the number of Orthogonal Frequency Division Multiplexing (OFDM) symbols, and the frequency domain may be defined by the number of subcarriers or the number of resource blocks. Furthermore, a Transmission Time Interval (TTI) in the time domain may be a slot or a subslot, and the TTI may be a subframe.

[0017] The base station 10 is capable of performing carrier aggregation, which aggregates multiple cells (multiple component carriers (CCs)) to communicate with the terminal 20. In carrier aggregation, one primary cell (PCell, Primary Cell) and one or more secondary cells (SCell, Secondary Cell) are used.

[0018] The base station 10 transmits a synchronization signal, system information, and the like to the terminal 20. The synchronization signal is, for example, NR-PSS and NR-SSS. The system information is, for example, transmitted by NR-PBCH or PDSCH, and is also called broadcast information. As shown in FIG. 1, the base station 10 transmits a control signal or data to the terminal 20 in DL (Downlink), and receives a control signal or data from the terminal 20 in UL (Uplink). Note that, here, what is transmitted by a control channel such as PUCCH or PDCCH is called a control signal, and what is transmitted by a shared channel such as PUSCH or PDSCH is called data, but these names are merely examples.

[0019] The terminal 20 is a communication device equipped with a wireless communication function, such as a smartphone, a mobile phone, a tablet, a wearable terminal, a communication module for M2M (Machine-to-Machine), etc. As shown in Fig. 1, the terminal 20 receives a control signal or data from the base station 10 in DL and transmits a control signal or data to the base station 10 in UL, thereby using various communication services provided by the wireless communication system. The terminal 20 may be called a UE, and the base station 10 may be called a gNB.

[0020] The terminal 20 can perform carrier aggregation, which aggregates multiple cells (multiple CCs) to communicate with the base station 10. In the carrier aggregation, one primary cell and one or more secondary cells are used. Also, a PUCCH-SCell having a PUCCH may be used.

[0021] In addition, NR is considering strengthening power saving in connected mode, such as reducing PDCCH (Physical Downlink Control Channel) monitoring when connected DRX (Discontinuous reception) is set and reducing power during DCI (Downlink Control Information)-based DRX active periods.

[0022] As operations related to reducing the PDCCH monitoring, switching of search space set groups and skipping PDCCH monitoring for a certain period of time are being considered.

[0023] Therefore, switching of a search space set or a search space set group and / or skipping PDCCH monitoring for a certain period may be notified from base station 10 to terminal 20. Furthermore, application start timing and / or end timing and / or application period of switching of a search space set or a search space set group and / or skipping PDCCH monitoring for a certain period may be specified or may be notified from base station 10 to terminal 20.

[0024] 2 is a sequence diagram for explaining an example of monitoring in an embodiment of the present invention. In step S1, the base station 10 transmits information related to PDCCH monitoring reduction to the terminal 20. The information related to PDCCH monitoring reduction may be information that triggers PDCCH monitoring, or may be information related to the application start timing and / or application end timing of the PDCCH monitoring reduction function. In the following step S2, the terminal 20 switches search space sets and / or executes PDCCH monitoring skip, i.e., the PDCCH monitoring reduction function, based on the information related to PDCCH monitoring reduction.

[0025] In the present disclosure, the switching of search space sets or search space set groups and / or skipping PDCCH monitoring for a certain period (including functions similar thereto) are described as PDCCH monitoring reduction functions. The present disclosure may be applied to switching of search space sets or search space set groups and / or skipping PDCCH monitoring for a certain period, or may be applied to other PDCCH monitoring reduction functions other than switching of search space sets or search space set groups and / or skipping PDCCH monitoring for a certain period. The PDCCH monitoring reduction function may correspond to other functions capable of PDCCH monitoring reduction.

[0026] As the PDCCH monitoring reduction function, one or more of 1)-4) shown below may be applied.

[0027] 1) Switching of search space sets or search space set groups may be notified. 2) PDCCH monitoring skip for a certain period of time may be notified. 3) Search space set or search space set group switching and PDCCH monitoring skip for a certain period may be notified at the same time. For example, they may be notified by a single DCI (Downlink Control Information), MAC-CE (Media Access Control - Control Element), etc. 4) Other PDCCH monitoring reduction functions may be notified.

[0028] Switching a search space set or a search space set group may be a function of switching a search space set group, a function of switching a search space set, or a function of switching any of the parameters related to the search space set.

[0029] A PDCCH monitoring skip for a certain period of time may be notified or specified as the length of time for which the PDCCH monitoring skip is performed, or may be notified or specified based on the number of times the PDCCH monitoring skip is performed (i.e., the length of time changes based on the PDCCH monitoring period), or the period for which the PDCCH monitoring skip is performed may be notified or specified based on other operations (e.g., the DRX cycle, etc.).

[0030] In the above step S1, the application start timing or application delay of the PDCCH monitoring function may be notified or specified. For example, the slot and / or symbol at which application starts, the number of slots and / or the number of symbols by which application is delayed, etc. may be notified or specified.

[0031] Also, in the above step S1, the application start timing or application delay may be notified or specified based on the reception timing of an explicit or implicit notification that triggers the PDCCH monitoring reduction function.

[0032] In addition, in the above step S1, the application start timing or the application delay may be notified or specified based on the timing of the ACK transmitted by the terminal 20. The ACK may be either or both of 1) and 2) shown below.

[0033] 1) It may be all ACKs that are expected or scheduled to be transmitted by the terminal 20 in the cell. In other words, it may include ACKs for DL ​​data received before and after the notification of the PDCCH monitoring reduction function.

[0034] 2) It may be an ACK for a notification of the PDCCH monitoring reduction function.

[0035] For example, it may be notified or specified that the PDCCH monitoring reduction function is applied immediately after the above-mentioned ACK, or it may be notified or specified that the PDCCH monitoring reduction function is applied a certain time after the above-mentioned ACK.

[0036] In addition, after receiving a notification to trigger the PDCCH monitoring reduction function in the above step S1, whether or not to apply the PDCCH monitoring reduction function may be notified or specified until the timing of the above-mentioned ACK transmitted by the terminal 20.

[0037] For example, it may be notified whether or not to skip PDCCH monitoring from the notification of the PDCCH monitoring reduction function to the timing of the ACK transmitted by the terminal 20, or PDCCH monitoring skip may be applied immediately after the transmission timing of the ACK or after a certain time later.

[0038] For example, it may be notified or specified that the operation up until the timing of the ACK transmission by the terminal 20 is different from the operation immediately after the ACK transmission timing or from a certain time later.

[0039] Regarding the application start timing or application delay of the PDCCH monitoring reduction function, different application start timing or application delay may be specified under different conditions. For example, the application start timing or application delay may be determined based on the type of DCI format, the value of a notified parameter, etc.

[0040] Furthermore, when a plurality of PDCCH monitoring reduction functions are applied, the application start timing or application delay may be specified for each function, or a common application start timing or application delay may be specified.

[0041] In addition, when applying multiple PDCCH monitoring reduction functions, the application start timing of a function may be specified based on the application start / end timing or application period of another function. For example, when PDCCH monitoring skip and search space set or search space set group switching are applied, the application of search space set or search space set group switching may start from the timing when the application of PDCCH monitoring skip ends.

[0042] In addition, in the above step S1, the application period or application end timing of the PDCCH monitoring reduction function may be notified or specified. For example, the number of slots and / or symbols to be applied, and the number of slots and / or symbols at which the application ends may be notified or specified.

[0043] PDCCH monitoring related parameters and / or operations to be applied within a notified or specified period may be notified or specified. For example, a PDCCH monitoring cycle to be applied within a period of several slots may be notified. In addition, other adaptation parameters (e.g., the maximum number of MIMO layers, etc.) may be notified.

[0044] Furthermore, in the above step S1, the application period or application end timing may be notified or specified based on the reception timing of an explicit or implicit notification that triggers the PDCCH monitoring reduction function.

[0045] For example, it may be notified or specified that the application period is X slots or the application end timing is Y slots later based on the reception timing of a notification that triggers the PDCCH monitoring reduction function. In other words, when the application start timing is notified or specified based on the timing of an ACK transmitted by terminal 20, the period during which the function is actually applied may change based on the transmission timing of the ACK.

[0046] Furthermore, the application period or application end timing may be notified or specified based on the timing of the ACK transmitted by the terminal 20 described above.

[0047] For example, the application period of X slots or the application end timing after Y slots may be notified or specified based on the timing of an ACK transmitted by the terminal 20. In other words, when the application start timing is notified or specified based on the timing of receiving a notification that triggers the PDCCH monitoring reduction function by the terminal 20, the period during which the function is actually applied may change based on the transmission timing of the ACK.

[0048] Regarding the application period or end timing of the PDCCH monitoring reduction function, different application periods or end timings may be specified under different conditions. For example, the application period or end timing may be determined based on the type of DCI format, the value of a parameter to be notified, etc.

[0049] Furthermore, when multiple PDCCH monitoring reduction functions are applied, an application period or application end timing may be specified for each function, or a common application period or application end timing may be specified.

[0050] In addition, when applying multiple PDCCH monitoring reduction functions, the application period or application end timing of a function may be specified based on the application start / end timing or application period of another function. For example, when PDCCH monitoring skip and search space set or search space set group switching are applied, the application of the search space set or search space set group switching may be ended at the timing when the application of PDCCH monitoring skip starts.

[0051] According to the above-described embodiment, the terminal 20 can execute the PDCCH monitoring reduction function by being notified or specified of the start and end of application of the PDCCH monitoring reduction function.

[0052] That is, power consumption can be reduced in the wireless communication system.

[0053] (Device configuration) Next, a functional configuration example of the base station 10 and the terminal 20 that execute the processes and operations described above will be described. The base station 10 and the terminal 20 include functions for executing the above-mentioned embodiments. However, the base station 10 and the terminal 20 may each include only one of the functions of the embodiments.

[0054] <Base station 10> Fig. 3 is a diagram showing an example of the functional configuration of the base station 10. As shown in Fig. 3, the base station 10 has a transmitting unit 110, a receiving unit 120, a setting unit 130, and a control unit 140. The functional configuration shown in Fig. 3 is merely an example. As long as the operation according to the embodiment of the present invention can be executed, the functional divisions and the names of the functional units may be any. The transmitting unit 110 and the receiving unit 120 may be called a communication unit.

[0055] The transmitting unit 110 has a function of generating a signal to be transmitted to the terminal 20 side and transmitting the signal wirelessly. The receiving unit 120 has a function of receiving various signals transmitted from the terminal 20 and acquiring, for example, information of a higher layer from the received signals. The transmitting unit 110 also has a function of transmitting NR-PSS, NR-SSS, NR-PBCH, DL / UL control signals, DL data, and the like to the terminal 20. The transmitting unit 110 also transmits setting information and the like described in the embodiment.

[0056] The setting unit 130 stores in a storage device setting information that is set in advance and various setting information to be transmitted to the terminal 20, and reads out the information from the storage device as necessary. The control unit 140 performs, for example, resource allocation and overall control of the base station 10. Note that the functional unit related to signal transmission in the control unit 140 may be included in the transmitting unit 110, and the functional unit related to signal reception in the control unit 140 may be included in the receiving unit 120. Furthermore, the transmitting unit 110 and the receiving unit 120 may be called a transmitter and a receiver, respectively.

[0057] <Terminal 20> Fig. 4 is a diagram showing an example of the functional configuration of the terminal 20. As shown in Fig. 4, the terminal 20 has a transmitting unit 210, a receiving unit 220, a setting unit 230, and a control unit 240. The functional configuration shown in Fig. 4 is merely an example. As long as the operation related to the embodiment of the present invention can be executed, the functional divisions and the names of the functional units may be any. The transmitting unit 210 and the receiving unit 220 may be called a communication unit.

[0058] The transmitter 210 creates a transmission signal from the transmission data and transmits the transmission signal wirelessly. The receiver 220 receives various signals wirelessly and acquires a higher layer signal from the received physical layer signal. The transmitter 210 also transmits HARQ-ACK, and the receiver 220 receives the setting information and the like described in the embodiment.

[0059] The setting unit 230 stores various setting information received from the base station 10 by the receiving unit 220 in a storage device, and reads it out from the storage device as necessary. The setting unit 230 also stores setting information that is set in advance. The control unit 240 performs control of the entire terminal 20, etc. Note that a functional unit related to signal transmission in the control unit 240 may be included in the transmitting unit 210, and a functional unit related to signal reception in the control unit 240 may be included in the receiving unit 220. Also, the transmitting unit 210 and the receiving unit 220 may be called a transmitter and a receiver, respectively.

[0060] (Hardware configuration) The block diagrams (FIGS. 3 and 4) used to explain the above embodiments show functional blocks. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized using one device that is physically or logically combined, or may be realized using two or more devices that are physically or logically separated and directly or indirectly connected (e.g., using wires, wirelessly, etc.) and these multiple devices. The functional blocks may be realized by combining the one device or the multiple devices with software.

[0061] Functions include, but are not limited to, judgment, determination, judgment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, consideration, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assignment. For example, a functional block (component) that performs the function of transmission is called a transmitting unit or a transmitter. In either case, as described above, there is no particular limitation on the method of realization.

[0062] For example, the base station 10, the terminal 20, etc. in an embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Fig. 5 is a diagram showing an example of a hardware configuration of the base station 10 and the terminal 20 according to an embodiment of the present disclosure. The above-mentioned base station 10 and the terminal 20 may be physically configured as a computer device including a processor 1001, a storage device 1002, an auxiliary storage device 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, etc.

[0063] In the following description, the term "apparatus" can be interpreted as a circuit, a device, a unit, etc. The hardware configuration of the base station 10 and the terminal 20 may be configured to include one or more of the devices shown in the figure, or may be configured to exclude some of the devices.

[0064] Each function in the base station 10 and the terminal 20 is realized by loading a specific software (program) onto hardware such as a processor 1001, a memory device 1002, etc., so that the processor 1001 performs calculations, controls communications by the communication device 1004, and controls at least one of reading and writing of data in the memory device 1002 and the auxiliary memory device 1003.

[0065] The processor 1001 controls the entire computer by running, for example, an operating system. The processor 1001 may be configured as a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic unit, a register, etc. For example, the above-mentioned control unit 140, control unit 240, etc. may be realized by the processor 1001.

[0066] Moreover, the processor 1001 reads out a program (program code), a software module, data, or the like from at least one of the auxiliary storage device 1003 and the communication device 1004 to the storage device 1002, and executes various processes according to the program. As the program, a program that causes a computer to execute at least a part of the operations described in the above-mentioned embodiment is used. For example, the control unit 140 of the base station 10 shown in FIG. 3 may be realized by a control program stored in the storage device 1002 and operated by the processor 1001. Also, for example, the control unit 240 of the terminal 20 shown in FIG. 4 may be realized by a control program stored in the storage device 1002 and operated by the processor 1001. Although the above-mentioned various processes have been described as being executed by one processor 1001, they may be executed by two or more processors 1001 simultaneously or sequentially. The processor 1001 may be implemented by one or more chips. The program may be transmitted from a network via a telecommunication line.

[0067] The storage device 1002 is a computer-readable recording medium, and may be configured by at least one of, for example, a Read Only Memory (ROM), an Erasable Programmable ROM (EPROM), an Electrically Erasable Programmable ROM (EEPROM), a Random Access Memory (RAM), etc. The storage device 1002 may also be called a register, a cache, a main memory (primary storage device), etc. The storage device 1002 can store a program (program code), software modules, etc. that are executable to implement a communication method according to an embodiment of the present disclosure.

[0068] The auxiliary storage device 1003 is a computer-readable recording medium, and may be, for example, at least one of an optical disk such as a CD-ROM (Compact Disc ROM), a hard disk drive, a flexible disk, a magneto-optical disk (e.g., a compact disk, a digital versatile disk, a Blu-ray (registered trademark) disk), a smart card, a flash memory (e.g., a card, a stick, a key drive), a floppy (registered trademark) disk, a magnetic strip, etc. The above-mentioned storage medium may be, for example, a database, a server, or other suitable medium including at least one of the storage device 1002 and the auxiliary storage device 1003.

[0069] The communication device 1004 is hardware (transmission and reception device) for performing communication between computers via at least one of a wired network and a wireless network, and is also called, for example, a network device, a network controller, a network card, a communication module, etc. The communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc., in order to realize at least one of Frequency Division Duplex (FDD) and Time Division Duplex (TDD). For example, a transmission and reception antenna, an amplifier unit, a transmission and reception unit, a transmission line interface, etc. may be realized by the communication device 1004. The transmission and reception unit may be implemented as a transmission unit and a reception unit that are physically or logically separated from each other.

[0070] The input device 1005 is an input device (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that accepts input from the outside. The output device 1006 is an output device (e.g., a display, a speaker, an LED lamp, etc.) that performs output to the outside. The input device 1005 and the output device 1006 may be integrated into one device (e.g., a touch panel).

[0071] In addition, each device such as the processor 1001 and the storage device 1002 is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or may be configured using different buses between each device.

[0072] Furthermore, the base station 10 and the terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), a field programmable gate array (FPGA), etc., and some or all of the functional blocks may be realized by the hardware. For example, the processor 1001 may be implemented using at least one of these pieces of hardware.

[0073] (Summary of the embodiment) As described above, according to an embodiment of the present invention, a terminal is provided which includes a receiving unit that receives downlink control information from a base station that instructs both switching of a search space set or a search space set group and skipping of PDCCH monitoring during a specified period, and a control unit that executes at least one of switching of the search space set or the search space set group or skipping of PDCCH monitoring during the specified period based on the downlink control information.

[0074] With the above configuration, it is possible to reduce power consumption in a wireless communication system.

[0075] In the above configuration, the receiving unit may receive delay information from the base station indicating a time for delaying the start of switching of the search space set or search space set group, and the control unit may perform switching of the search space set or search space set group after the time indicated by the delay information from the reception of the downlink control information.

[0076] In the above configuration, the time from reception of the downlink control information to start of skipping the PDCCH monitoring may be different from the time from reception of the downlink control information to start of switching the search space set or search space set group.

[0077] In the above configuration, the downlink control information includes a parameter instructing switching of the search space set or search space set group and skipping of PDCCH monitoring during the specified period, and the specified period may differ depending on the value of the parameter.

[0078] In the above configuration, the receiving unit may receive information indicating a period for skipping the PDCCH monitoring from the base station, and the control unit may determine the specified period based on the period indicated by the information and the value of the parameter.

[0079] Furthermore, according to an embodiment of the present invention, a communication method executed by a terminal includes a receiving unit that receives downlink control information from a base station, the downlink control information instructing both switching of a search space set or a search space set group and skipping of PDCCH (Physical Downlink Control Channel) monitoring during a specified period, and a control unit that executes at least one of switching of the search space set or the search space set group or skipping of PDCCH monitoring during the specified period based on the downlink control information.

[0080] With the above configuration, terminal 20 can execute the PDCCH monitoring reduction function, which means that power consumption can be reduced in the wireless communication system.

[0081] (Supplementary embodiment) Although the embodiment of the present invention has been described above, the disclosed invention is not limited to such an embodiment, and those skilled in the art will understand various modifications, modifications, alternatives, replacements, and the like. Although the description has been given using specific numerical examples to facilitate understanding of the invention, unless otherwise specified, those numerical values ​​are merely examples and any appropriate values ​​may be used. The division of items in the above description is not essential to the present invention, and matters described in two or more items may be used in combination as necessary, and matters described in one item may be applied to matters described in another item (as long as there is no contradiction). The boundaries of functional units or processing units in the functional block diagram do not necessarily correspond to the boundaries of physical parts. The operations of multiple functional units may be physically performed by one part, or the operations of one functional unit may be physically performed by multiple parts. The order of the processing procedures described in the embodiment may be changed as long as there is no contradiction. For convenience of the processing description, the base station 10 and the terminal 20 have been described using functional block diagrams, but such devices may be realized by hardware, software, or a combination thereof. The software operated by the processor possessed by the base station 10 in accordance with an embodiment of the present invention and the software operated by the processor possessed by the terminal 20 in accordance with an embodiment of the present invention may each be stored in a random access memory (RAM), flash memory, read only memory (ROM), EPROM, EEPROM, register, hard disk (HDD), removable disk, CD-ROM, database, server or any other suitable storage medium.

[0082] Furthermore, the notification of information is not limited to the aspects / embodiments described in the present disclosure, and may be performed using other methods. For example, the notification of information may be performed by physical layer signaling (e.g., Downlink Control Information (DCI), Uplink Control Information (UCI)), higher layer signaling (e.g., Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information (Master Information Block (MIB), System Information Block (SIB)), other signals, or a combination of these. Furthermore, the RRC signaling may be called an RRC message, and may be, for example, an RRC Connection Setup message, an RRC Connection Reconfiguration message, or the like.

[0083] Each aspect / embodiment described in the present disclosure may be applied to at least one of systems using LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), FRA (Future Radio Access), NR (new Radio), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, UWB (Ultra-WideBand), Bluetooth (registered trademark), and other suitable systems, and next-generation systems extended based on these. In addition, a combination of multiple systems (e.g., a combination of at least one of LTE and LTE-A and 5G, etc.) may be applied.

[0084] The steps, sequences, flow charts, etc. of each aspect / embodiment described herein may be reordered unless inconsistent. For example, the methods described in this disclosure present elements of various steps using an example order, and are not limited to the particular order presented.

[0085] In this specification, a specific operation performed by the base station 10 may be performed by its upper node in some cases. In a network consisting of one or more network nodes having the base station 10, it is clear that various operations performed for communication with the terminal 20 may be performed by at least one of the base station 10 and other network nodes other than the base station 10 (e.g., MME or S-GW, etc., but are not limited to these). Although the above example illustrates a case in which there is one other network node other than the base station 10, the other network node may be a combination of multiple other network nodes (e.g., MME and S-GW).

[0086] The information or signals described in the present disclosure may be output from a higher layer (or a lower layer) to a lower layer (or a higher layer), or may be input / output via multiple network nodes.

[0087] The input and output information may be stored in a specific location (e.g., memory) or may be managed using a management table. The input and output information may be overwritten, updated, or added to. The output information may be deleted. The input information may be transmitted to another device.

[0088] In the present disclosure, the determination may be made based on a value represented by one bit (0 or 1), a Boolean value (true or false), or a numerical comparison (e.g., comparison with a predetermined value).

[0089] Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0090] Additionally, software, instructions, information, etc. may be transmitted or received over a transmission medium. For example, if the software is transmitted from a website, server, or other remote source using wired and / or wireless technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL)), and / or wireless technologies (such as infrared, microwave, etc.), then these wired and / or wireless technologies are included within the definition of transmission media.

[0091] The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, the data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0092] In addition, the terms described in this disclosure and the terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, at least one of a channel and a symbol may be a signal (signaling). Also, a signal may be a message. Also, a component carrier (CC) may be called a carrier frequency, a cell, a frequency carrier, etc.

[0093] As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0094] In addition, the information, parameters, etc. described in the present disclosure may be represented using absolute values, may be represented using relative values ​​from a predetermined value, or may be represented using other corresponding information. For example, a radio resource may be indicated by an index.

[0095] The names used for the above-mentioned parameters are not limiting in any way. Moreover, the formulas using these parameters may differ from those explicitly disclosed in this disclosure. The various channels (e.g., PUCCH, PDCCH, etc.) and information elements may be identified by any suitable names, and therefore the various names assigned to these various channels and information elements are not limiting in any way.

[0096] In the present disclosure, terms such as "base station (BS)", "radio base station", "base station", "fixed station", "NodeB", "eNodeB (eNB)", "gNodeB (gNB)", "access point", "transmission point", "reception point", "transmission / reception point", "cell", "sector", "cell group", "carrier", "component carrier", etc. may be used interchangeably. A base station may also be referred to by terms such as a macro cell, a small cell, a femto cell, a pico cell, etc.

[0097] A base station can accommodate one or more (e.g., three) cells. When a base station accommodates multiple cells, the entire coverage area of ​​the base station can be divided into multiple smaller areas, and each smaller area can also be provided with communication services by a base station subsystem (e.g., a small indoor base station (RRH: Remote Radio Head). The term "cell" or "sector" refers to a part or the entire coverage area of ​​a base station and / or a base station subsystem that provides communication services in this coverage.

[0098] In this disclosure, the terms "Mobile Station (MS)", "user terminal", "User Equipment (UE)", "terminal", etc. may be used interchangeably.

[0099] A mobile station may also be referred to by those skilled in the art as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable terminology.

[0100] At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a communication device, etc. At least one of the base station and the mobile station may be a device mounted on a moving body, the moving body itself, etc. The moving body may be a vehicle (e.g., a car, an airplane, etc.), an unmanned moving body (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). At least one of the base station and the mobile station may include a device that does not necessarily move during communication operation. For example, at least one of the base station and the mobile station may be an IoT (Internet of Things) device such as a sensor.

[0101] Furthermore, the base station in the present disclosure may be read as a user terminal. For example, each aspect / embodiment of the present disclosure may be applied to a configuration in which communication between a base station and a user terminal is replaced with communication between a plurality of terminals 20 (which may be called, for example, D2D (Device-to-Device) or V2X (Vehicle-to-Everything)). In this case, the terminal 20 may be configured to have the functions of the base station 10 described above. Furthermore, terms such as "uplink" and "downlink" may be read as terms corresponding to terminal-to-terminal communication (for example, "side"). For example, an uplink channel, a downlink channel, etc. may be read as a side channel.

[0102] Similarly, a user terminal in the present disclosure may be read as a base station. In this case, the base station may be configured to have the functions of the above-mentioned user terminal.

[0103] As used in this disclosure, the terms "determining" and "determining" may encompass a wide variety of actions. "Determining" and "determining" may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up, search, inquiry (e.g., searching in a table, database, or other data structure), ascertaining, and the like. "Determining" and "determining" may also include receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in a memory), and the like. In addition, "judgment" and "decision" can include considering resolving, selecting, choosing, establishing, comparing, etc., to be a "judgment" or "decision." In other words, "judgment" and "decision" can include considering some action to be a "judgment" or "decision." In addition, "judgment" can be interpreted as "assuming," "expecting," "considering," etc.

[0104] The terms "connected," "coupled," or any variation thereof, refer to any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, "connected" may be read as "access." As used in this disclosure, two elements may be considered to be "connected" or "coupled" to each other using at least one of one or more wires, cables, and printed electrical connections, as well as electromagnetic energy having wavelengths in the radio frequency range, microwave range, and optical (both visible and invisible) range, as some non-limiting and non-exhaustive examples.

[0105] The reference signal may be abbreviated as RS (Reference Signal) and may be called a pilot depending on the applicable standard.

[0106] As used in this disclosure, the phrase "based on" does not mean "based only on," unless expressly stated otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

[0107] Any reference to an element using a designation such as "first," "second," etc., used in this disclosure does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements. Thus, a reference to a first and a second element does not imply that only two elements may be employed or that the first element must precede the second element in some way.

[0108] The "means" in the configuration of each of the above devices may be replaced with "part," "circuit," "device," etc.

[0109] When the terms "include," "including," and variations thereof are used in this disclosure, these terms are intended to be inclusive, similar to the term "comprising." Further, when used in this disclosure, the term "or" is not intended to be an exclusive or.

[0110] A radio frame may be composed of one or more frames in the time domain. Each of the one or more frames in the time domain may be called a subframe. A subframe may further be composed of one or more slots in the time domain. A subframe may have a fixed time length (e.g., 1 ms) that is independent of numerology.

[0111] The numerology may be communication parameters that apply to the transmission and / or reception of a signal or channel, such as, for example, at least one of a subcarrier spacing (SCS), a bandwidth, a symbol length, a cyclic prefix length, a transmission time interval (TTI), a number of symbols per TTI, a radio frame structure, a particular filtering operation that the transceiver performs in the frequency domain, a particular windowing operation that the transceiver performs in the time domain, etc.

[0112] A slot may be composed of one or more symbols (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol, a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol, etc.) in the time domain. A slot may be a time unit based on numerology.

[0113] A slot may include multiple minislots. Each minislot may be composed of one or multiple symbols in the time domain. A minislot may also be called a subslot. A minislot may be composed of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a minislot may be called PDSCH (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called PDSCH (or PUSCH) mapping type B.

[0114] A radio frame, a subframe, a slot, a minislot, and a symbol each represent a time unit for transmitting a signal. The radio frame, the subframe, the slot, the minislot, and the symbol may each be referred to by a different name.

[0115] For example, one subframe may be called a transmission time interval (TTI), multiple consecutive subframes may be called a TTI, or one slot or one minislot may be called a TTI. That is, at least one of the subframe and the TTI may be a subframe (1 ms) in the existing LTE, a period shorter than 1 ms (for example, 1-13 symbols), or a period longer than 1 ms. Note that the unit expressing the TTI may be called a slot, a minislot, or the like, instead of a subframe.

[0116] Here, TTI refers to, for example, the minimum time unit for scheduling in wireless communication. For example, in an LTE system, a base station performs scheduling to allocate wireless resources (such as frequency bandwidth and transmission power that can be used by each terminal 20) to each terminal 20 in TTI units. Note that the definition of TTI is not limited to this.

[0117] The TTI may be a transmission time unit for a channel-encoded data packet (transport block), a code block, a code word, etc., or may be a processing unit for scheduling, link adaptation, etc. When a TTI is given, the time interval (e.g., the number of symbols) in which a transport block, a code block, a code word, etc. are actually mapped may be shorter than the TTI.

[0118] In addition, when one slot or one minislot is called TTI, one or more TTIs (i.e., one or more slots or one or more minislots) may be the minimum time unit of scheduling. Also, the number of slots (minislots) constituting the minimum time unit of scheduling may be controlled.

[0119] A TTI having a time length of 1 ms may be called a normal TTI (TTI in LTE Rel. 8-12), a normal TTI, a long TTI, a normal subframe, a normal subframe, a long subframe, a slot, etc. A TTI shorter than a normal TTI may be called a shortened TTI, a short TTI, a partial or fractional TTI, a shortened subframe, a short subframe, a minislot, a subslot, a slot, etc.

[0120] In addition, a long TTI (e.g., a normal TTI, a subframe, etc.) may be interpreted as a TTI having a time length exceeding 1 ms, and a short TTI (e.g., a shortened TTI, etc.) may be interpreted as a TTI having a TTI length shorter than the TTI length of a long TTI and equal to or greater than 1 ms.

[0121] A resource block (RB) is a resource allocation unit in the time domain and the frequency domain, and may include one or more consecutive subcarriers in the frequency domain. The number of subcarriers included in an RB may be the same regardless of the numerology, for example, 12. The number of subcarriers included in an RB may be determined based on the numerology.

[0122] In addition, the time domain of the RB may include one or more symbols and may be one slot, one minislot, one subframe, or one TTI in length. Each of one TTI, one subframe, etc. may be composed of one or more resource blocks.

[0123] Note that one or more RBs may be called a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, or the like.

[0124] Furthermore, a resource block may be composed of one or more resource elements (REs). For example, one RE may be a radio resource region of one subcarrier and one symbol.

[0125] A Bandwidth Part (BWP), which may also be referred to as a fractional bandwidth, may represent a subset of contiguous common resource blocks (RBs) for a numerology on a carrier, where the common RBs may be identified by an index of the RBs relative to a common reference point of the carrier. PRBs may be defined in a BWP and numbered within the BWP.

[0126] The BWP may include a BWP for UL (UL BWP) and a BWP for DL ​​(DL BWP). For the terminal 20, one or more BWPs may be set within one carrier.

[0127] At least one of the configured BWPs may be active, and the terminal 20 may not expect to transmit or receive a predetermined signal / channel outside the active BWP. Note that the terms "cell", "carrier", and the like in this disclosure may be replaced with "BWP".

[0128] The above-mentioned structures of radio frames, subframes, slots, minislots, symbols, etc. are merely examples. For example, the number of subframes included in a radio frame, the number of slots per subframe or radio frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in an RB, the number of symbols in a TTI, the symbol length, the cyclic prefix (CP) length, etc. may be changed in various ways.

[0129] In this disclosure, where articles have been added due to translation, such as a, an, and the in English, the disclosure may include that the nouns following these articles are in the plural form.

[0130] In the present disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "coupled" may also be interpreted in the same way as "different."

[0131] Each aspect / embodiment described in this disclosure may be used alone, in combination, or switched according to execution. In addition, notification of predetermined information (e.g., notification that "X is the case") is not limited to being done explicitly, but may be done implicitly (e.g., not notifying the predetermined information).

[0132] Although the present disclosure has been described in detail above, it is clear to those skilled in the art that the present disclosure is not limited to the embodiments described in the present disclosure. The present disclosure can be implemented in modified and altered forms without departing from the spirit and scope of the present disclosure as defined by the claims. Therefore, the description of the present disclosure is intended to be illustrative and does not have any limiting meaning on the present disclosure. [Explanation of symbols]

[0133] 10 base station 110 Transmitter 120 Receiving unit 130 Setting section 140 Control section 20 Terminals 210 Transmitter 220 Receiving unit 230 Setting section 240 Control Unit 1001 Processor 1002 Storage device 1003 Auxiliary storage device 1004 Communication equipment 1005 Input Device 1006 Output device

Claims

1. A receiver that receives downlink control information from a base station, the downlink control information instructing both switching of a search space set or a search space set group and skipping of a PDCCH (Physical Downlink Control Channel) monitoring during a predetermined period; A terminal comprising: a control unit that performs at least one of switching the search space set or search space set group, or skipping PDCCH monitoring during the specified period based on the downlink control information.

2. The receiving unit receives delay information indicating a time for delaying a start of switching of the search space set or the search space set group from the base station; The terminal according to claim 1 , wherein the control unit switches the search space set or the search space set group after a time indicated by the delay information has elapsed since reception of the downlink control information.

3. The terminal according to claim 1 , wherein a time from reception of the downlink control information to start of skipping the PDCCH monitoring is different from a time from reception of the downlink control information to start of switching of the search space set or the search space set group.

4. the downlink control information includes a parameter instructing switching of the search space set or the search space set group and skipping of PDCCH monitoring during the predetermined period, The terminal of claim 1 , wherein the predetermined period of time varies depending on the value of the parameter.

5. The receiving unit receives information indicating a period during which the PDCCH monitoring is skipped from the base station, The terminal according to claim 4 , wherein the control unit determines the predetermined period based on a period indicated by the information and a value of the parameter.

6. A communication method performed by a terminal, comprising: A receiver that receives downlink control information from a base station, the downlink control information instructing both switching of a search space set or a search space set group and skipping of a PDCCH (Physical Downlink Control Channel) monitoring during a predetermined period; A control unit that performs at least one of switching the search space set or search space set group, or skipping PDCCH monitoring during the specified period based on the downlink control information.

Images