Terminal and communication method

Abstract

The terminal has: a receiving unit that receives information related to a reference signal; and a control unit that uses the reference signal in an RRC (Radio Resource Control) idle state or an RRC inactive state based on the information.

Description

Technical Field

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

[0002] In NR (New Radio), which is a successor system to LTE (Long Term Evolution), technologies that meet requirements such as a large-capacity system, high data transfer speed, low latency, simultaneous connection of multiple terminals, low cost, and power saving are being studied (for example, Non-Patent Document 1). 5G is a mobile communication system that supports high-frequency bands such as millimeter waves exceeding 10 GHz. Ultra-high-speed wireless data communication in the order of several Gbps can be achieved by using a bandwidth of several hundred MHz, which is significantly wider than that of existing systems such as LTE.

[0003] In NR, reference signals such as TRS (Tracking reference signal) for time synchronization or frequency synchronization and CSI-RS (Channel state information Referencesignal) for channel state estimation are adopted. Regarding these reference signals, information on the reference signals is notified to terminals in the RRC (Radio Resource Control) connected state (RRC_CONNECTED) and used.

[0004] Prior Art Documents

[0005] Non-Patent Documents

[0006] Non-Patent Document 1: 3GPP TS 38.300 V16.0.0 (2019-12) Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] On the other hand, in terminals in the RRC idle state (RRC_IDLE) or RRC inactive state (RRC_INACTIVE), an SSB (SS / PBCH block) is used for time synchronization or frequency synchronization. However, due to the lack of flexibility in resource allocation of the SSB, the position of resources where synchronization can be performed is limited.

[0009] The present invention has been made in view of the above circumstances, and an object thereof is to increase the positions in the time domain where synchronization can be performed in a wireless communication system.

[0010] Means for Solving the Problems

[0011] According to the disclosed technology, there is provided a terminal having: a receiving unit that receives information related to a reference signal; and a control unit that uses the reference signal in an RRC (Radio Resource Control) idle state or an RRC inactive state based on the information.

[0012] Advantageous Effects of the Invention

[0013] According to the disclosed technology, in a wireless communication system, it is possible to increase the number of time-domain positions enabling synchronization. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 FIG. is a diagram showing a structural example of a wireless communication system in an embodiment of the present invention.

[0015] Figure 2 FIG. is a diagram showing an example (1) of resource allocation in an embodiment of the present invention.

[0016] Figure 3 FIG. is a diagram showing an example (2) of resource allocation in an embodiment of the present invention.

[0017] Figure 4 FIG. is a timing diagram for explaining an example (1) of a process related to synchronization in an embodiment of the present invention.

[0018] Figure 5 FIG. is a flowchart for explaining an example (2) of a process related to synchronization in an embodiment of the present invention.

[0019] Figure 6 FIG. is a flowchart for explaining an example (3) of a process related to synchronization in an embodiment of the present invention.

[0020] Figure 7 FIG. is a diagram showing an example of a functional structure of a base station 10 in an embodiment of the present invention.

[0021] Figure 8 FIG. is a diagram showing an example of a functional structure of a terminal 20 in an embodiment of the present invention.

[0022] Figure 9 FIG. is a diagram showing an example of a hardware structure of a base station 10 or a terminal 20 in an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the embodiments described below are merely examples, and the embodiments applying the present invention are not limited to the following embodiments.

[0024] When the wireless communication system according to the embodiment of the present invention operates, existing technologies are appropriately used. However, such existing technologies are, for example, existing LTE, but are not limited to existing LTE. In addition, unless otherwise specified, the term "LTE" used in this specification has a broad meaning including LTE-Advanced and subsequent modes (e.g., NR).

[0025] In addition, in the embodiments 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. These are for ease of description, and signals, functions, etc. identical to these may also be referred to by other names. In addition, the above terms in NR correspond to NR-SS, NR-PSS, NR-SSS, NR-PBCH, NR-PRACH, NR-PDCCH, NR-PDSCH, NR-PUCCH, NR-PUSCH, etc. However, even signals used in NR are not necessarily labeled as "NR-".

[0026] In addition, in the embodiments of the present invention, the duplex mode may be a TDD (Time Division Duplex) mode, an FDD (Frequency Division Duplex) mode, or a mode other than these (e.g., Flexible Duplex, etc.).

[0027] In addition, in the embodiments of the present invention, "configuring" wireless parameters, etc. may be pre-configuring predetermined values or configuring wireless parameters notified from the base station 10 or the terminal 20.

[0028] Figure 1 This is a diagram showing a structural example of a wireless communication system in an embodiment of the present invention. As Figure 1 shown, it includes a base station 10 and a terminal 20. In Figure 1 this, one base station 10 and one terminal 20 are each shown, but this is only an example, and there can be multiple of each. Additionally, the terminal 20 may also be referred to as a "user device". Furthermore, the wireless communication system in this embodiment may also be referred to as an NR-U system.

[0029] 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 the wireless signal are defined by the time domain and the frequency domain. The time domain can be defined by time slots or OFDM symbols, and the frequency domain can be defined by subbands, subcarriers, or resource blocks.

[0030] As Figure 1 shown, the base station 10 sends control information or data to the terminal 20 via DL (Downlink), and receives control information or data from the terminal 20 via UL (Uplink). Both the base station 10 and the terminal 20 are capable of performing beamforming for signal transmission and reception. In addition, both the base station 10 and the terminal 20 are capable of applying communication based on MIMO (Multiple Input Multiple Output) to DL or UL. Furthermore, both the base station 10 and the terminal 20 may communicate via SCell (Secondary Cell) and PCell (Primary Cell) based on CA (Carrier Aggregation).

[0031] The terminal 20 is a communication device with a wireless communication function such as a smartphone, mobile phone, tablet computer, wearable terminal, communication module for M2M (Machine-to-Machine), etc. As Figure 1 shown, the terminal 20 receives control information or data from the base station 10 via DL, and sends control information or data to the base station 10 via UL, thereby utilizing various communication services provided by the wireless communication system.

[0032] Additionally, NR-DC (NR-Dual connectivity) may also be executed. There is a base station 10A as the MN (Master Node) and a base station 10B as the SN (Secondary Node). The base station 10A and the base station 10B are each connected to the core network. The terminal 20 communicates with both the base station 10A and the base station 10B.

[0033] The cell group provided by the base station 10A serving as the MN is referred to as the MCG (Master Cell Group), and the cell group provided by the base station 10B serving as the SN is referred to as the SCG (Secondary Cell Group).

[0034] In NR, there are reference signals such as the TRS (Tracking reference signal) for time synchronization and / or frequency synchronization (tracking), and the CSI-RS (Channel state information Reference signal) for channel state information estimation (including measurement reporting). The information of these reference signals is notified to the terminal 20 in the RRC connected state (RRC_CONNECTED) and utilized. Additionally, the TRS can be defined as the CSI-RS for tracking.

[0035] On the other hand, in the terminal in the RRC idle state (RRC_IDLE) or the RRC inactive state (RRC_INACTIVE), the SSB (SS / PBCH block) is used for time synchronization or frequency synchronization. However, due to the lack of flexibility in the resource configuration of the SSB, the positions of the resources capable of performing synchronization are limited.

[0036] Regarding the TRS and CSI-RS for the terminal 20 in the RRC connected state, information related to resource configuration (such as period, density, position, etc.) can be flexibly set. On the other hand, for the SSB (SS / PBCH block) for the terminal 20 in the RRC idle state or the RRC inactive state, the resource configuration cannot be flexibly set.

[0037] In particular, during multi-beam operation in FR2 (Frequency range 2), etc., multiple TRS / CSI-RS / SSB corresponding to different beams are used. However, since there are fewer candidate positions on the resources that form the positional relationship capable of configuring multiple SSBs, the restrictions related to resource position setting sometimes become more significant.

[0038] Furthermore, the terminal 20 in the RRC idle state or the RRC inactive state needs to perform time / frequency tracking (synchronization) in advance in order to monitor paging information or perform measurements, etc. However, due to the restrictions related to the resource configuration of the SSB, the positions where time / frequency tracking (synchronization) or measurements, etc. can be performed are limited.

[0039] Since the positions where time / frequency tracking (synchronization) or measurement can be performed are limited, for example, the time positions of operations such as monitoring, measuring, and time / frequency tracking (synchronization) of paging information are discrete, and thus the power consumption of the terminal 20 may increase. That is, if the above-described operations can be aggregated as much as possible at continuous timings, the sleep time of the terminal 20 can be increased and the power consumption can be reduced.

[0040] Therefore, information related to the TRS and / or CSI-RS can be notified to the terminal 20 in the RRC idle state or the RRC inactive state. The information related to the TRS and / or CSI-RS can be, for example, the position of the resource. For example, the information related to the TRS and / or CSI-RS can also be notified to the terminal 20 in the RRC idle state or the RRC inactive state through broadcast information. In the following description, "at least one of the TRS and the CSI-RS" is expressed as "TRS / CSI-RS".

[0041] Figure 2 FIG. is an example (1) of resource configuration in an embodiment of the present invention. As Figure 2 shown, the relative position or offset of the TRS / CSI-RS with respect to the resource associated with paging (e.g., the PDCCH monitoring position for paging) can be notified to the terminal 20 in the RRC idle state or the RRC inactive state. This offset can also be the relative position with respect to the PF (Paging Frame).

[0042] Figure 3 FIG. is an example (2) of resource configuration in an embodiment of the present invention. As Figure 3 shown, the relative position or offset of the TRS / CSI-RS with respect to each SSB can be notified to the terminal 20 in the RRC idle state or the RRC inactive state. For example, an offset indicating X time slots ahead of SSB #0 can be notified to the terminal 20. The offsets of the TRS / CSI-RS with respect to each SSB can be the same or different respectively.

[0043] In addition, information related to the resource position of the TRS / CSI-RS can be directly notified to the terminal 20. For example, information indicating the time position based on the period and the offset, the RB (Resource block) position within the BWP (Bandwidth Part), etc. can be notified to the terminal 20.

[0044] In addition, regarding the time position and the frequency position, they can also be specified respectively through the above different options. For example, the time position can be notified to the terminal 20 by specifying the relative position with respect to the paging resource, and the frequency position can be notified to the terminal 20 by specifying the RB position within the BWP.

[0045] Furthermore, for example, in the case where multiple paging resources or multiple SSBs (SSBs with different SSB indices, such as SSB#0, SSB#1,... etc.) corresponding to multiple beams are set, the resource position of the TRS / CSI-RS can be notified as the relative position with respect to each of the multiple paging resources or multiple SSBs. The terminal 20 can assume that the beam of the TRS / CSI-RS is the same as the beam applied to the corresponding paging resource or SSB. That is, Quasi co-location Type D can be assumed between the TRS / CSI-RS and the corresponding paging resource or SSB. Regarding QCL of types different from Type D, QCL can also be assumed between the TRS / CSI-RS and the corresponding paging resource or SSB in the same way.

[0046] Figure 4 It is a timing diagram for explaining Example (1) of the processing related to synchronization in the embodiment of the present invention. In step S11, the terminal 20 is in the RRC idle state or the RRC inactive state. Then, the base station 10 sends the above information related to the TRS / CSI-RS to the terminal 20 as broadcast information, for example (S12). In step S13, the terminal 20 utilizes the TRS / CSI-RS sent from the base station 10 according to the received information related to the TRS / CSI-RS. That is, the terminal 20 in the RRC idle state or the RRC inactive state can perform time synchronization and / or frequency synchronization by utilizing the TRS / CSI-RS sent from the base station 10 according to the received above information related to the TRS / CSI-RS. In addition, the terminal 20 in the RRC idle state or the RRC inactive state can also perform channel estimation and / or measurement by utilizing the TRS / CSI-RS sent from the base station 10 according to the received above information related to the TRS / CSI-RS.

[0047] Figure 5It is a flowchart of Example (2) for explaining the synchronization-related processing in the embodiments of the present invention. In step S21, the terminal 20 is in the RRC connected state. Next, the base station 10 sends the above-mentioned information related to TRS / CSI-RS to the terminal 20 through various signaling (S22). The various signaling can be, for example, RRC signaling, MAC signaling, or PHY signaling. In step S23, the terminal 20 migrates from the RRC connected state to the RRC idle state or the RRC inactive state. In step S24, the terminal 20 utilizes the TRS / CSI-RS sent from the base station 10 according to the information related to TRS / CSI-RS received in the RRC connected state. The terminal 20 in the RRC idle state or the RRC inactive state can perform time synchronization and / or frequency synchronization by utilizing the TRS / CSI-RS sent from the base station 10 according to the above-mentioned information related to TRS / CSI-RS received in the RRC connected state. In addition, the terminal 20 in the RRC idle state or the RRC inactive state can also perform channel estimation and / or measurement by utilizing the TRS / CSI-RS sent from the base station 10 according to the received above-mentioned information related to TRS / CSI-RS.

[0048] That is, even if the terminal 20 that has migrated to the RRC connected state later migrates to the RRC idle state or the RRC inactive state, it can be assumed that the signal is sent from the base station 10 at the position of the TRS / CSI-RS in the RRC connected state and the processing is performed.

[0049] Regarding the assumption related to the beam (spatial information), even if it migrates to the RRC idle state or the RRC inactive state, the assumption in the RRC connected state can be maintained. That is, the terminal 20 can assume QCL type D between the TRS / CSI-RS in the RRC connected state and the TRS / CSI-RS in the RRC idle state or the RRC inactive state.

[0050] The information related to TRS / CSI-RS sent from the base station 10 in the above step S22 can be information that can be commonly used in the connected state and the idle state or the inactive state. Or, the information related to TRS / CSI-RS sent from the base station 10 in the above step S22 can also be information used in the idle state or the inactive state. That is, different information related to TRS / CSI-RS can be set in the connected state, the idle state, or the inactive state.

[0051] Figure 6This is a flowchart of Example (3) for explaining the synchronization-related processing in the embodiments of the present invention. In step S31, the terminal 20 is in the RRC connected state. Then, the base station 10 sends the above-mentioned TRS / CSI-RS-related information to the terminal 20 through various signaling (S32). The various signaling can be, for example, RRC signaling, MAC signaling, or PHY signaling. In step S33, the terminal 20 migrates from the RRC connected state to the RRC idle state or the RRC inactive state. In step S34, the terminal 20 performs cell selection. In step S35, the terminal 20 uses the TRS / CSI-RS sent from the base station 10 according to the TRS / CSI-RS-related information received in the cell before cell selection. The terminal 20 can perform time synchronization and / or frequency synchronization by using the TRS / CSI-RS sent from the base station 10 according to the received above-mentioned TRS / CSI-RS-related information. In addition, the terminal 20 can also perform channel estimation and / or measurement by using the TRS / CSI-RS sent from the base station 10 according to the received above-mentioned TRS / CSI-RS-related information.

[0052] The cell selection in step S34 can also be cell reselection. In addition, after performing the cell selection in step S34, the base station 10 can also change to another base station 10. In addition, in the case of reselecting a cell, whether to continue using the TRS / CSI-RS-related information can be notified by the network or specified by the specification.

[0053] According to the above embodiments, even when in the RRC idle state or the RRC inactive state, the terminal 20 can increase the position in the time domain where synchronization is possible and perform high-precision time synchronization and / or frequency synchronization by obtaining the TRS / CSI-RS-related information and using the TRS / CSI-RS.

[0054] That is, in a wireless communication system, it is possible to increase the position in the time domain where synchronization is possible.

[0055] (Functional Structure)

[0056] Next, a functional structure example of the base station 10 and the terminal 20 that perform the above-described processing and operations will be described. The base station 10 and the terminal 20 include the functions of implementing the above embodiments. However, the base station 10 and the terminal 20 may each only have a part of the functions in the embodiments.

[0057] <Base Station 10>

[0058] Figure 7 This is a diagram showing an example of the functional structure of the base station 10 in the embodiments of the present invention. As Figure 7As shown, the base station 10 includes a transmission unit 110, a reception unit 120, a setting unit 130, and a control unit 140. Figure 7 The functional structure shown is merely an example. As long as it can perform the operations involved in the embodiments of the present invention, the functional division and the names of the functional units can be arbitrary.

[0059] The transmission unit 110 has a function of generating a signal to be transmitted to the terminal 20 side and transmitting the signal wirelessly. In addition, the transmission unit 110 transmits inter-network node messages to other network nodes. The reception unit 120 includes a function of receiving various signals transmitted from the terminal 20 wirelessly and obtaining, for example, higher layer information from the received signals. In addition, the transmission unit 110 has a function of transmitting NR-PSS, NR-SSS, NR-PBCH, DL / UL control signals, and reference signals, etc. to the terminal 20. In addition, the reception unit 120 receives inter-network node messages from other network nodes. The transmission unit 110 and the reception unit 120 may be combined as a communication unit.

[0060] The setting unit 130 stores preset setting information and various setting information to be transmitted to the terminal 20 in a storage device, and reads them out from the storage device as needed. The content of the setting information is, for example, information required for synchronization, etc.

[0061] As described in the embodiments, the control unit 140 performs control related to synchronization. The functional units related to signal transmission in the control unit 140 may be included in the transmission unit 110, and the functional units related to signal reception in the control unit 140 may be included in the reception unit 120.

[0062] <Terminal 20>

[0063] Figure 8 is a diagram showing an example of the functional structure of the terminal 20 in the embodiments of the present invention. As Figure 8 shown, the terminal 20 includes a transmission unit 210, a reception unit 220, a setting unit 230, and a control unit 240. Figure 8 The functional structure shown is merely an example. As long as it can perform the operations involved in the embodiments of the present invention, the functional division and the names of the functional units can be arbitrary.

[0064] The transmitting unit 210 has a function of generating a transmission signal based on transmission data and transmitting the transmission signal wirelessly. The receiving unit 220 receives various signals wirelessly and obtains a higher-layer signal from the received physical layer signal. In addition, the receiving unit 220 has a function of receiving NR-PSS, NR-SSS, NR-PBCH, DL / UL / SL control signals, etc. transmitted from the base station 10. In addition, for example, in D2D communication, the transmitting unit 210 transmits PSCCH (Physical Sidelink Control Channel), PSSCH (Physical Sidelink Shared Channel), PSDCH (Physical Sidelink Discovery Channel), PSBCH (Physical Sidelink Broadcast Channel), etc. to another terminal 20, and the receiving unit 220 receives PSCCH, PSSCH, PSDCH, or PSBCH, etc. from another terminal 20. The transmitting unit 210 and the receiving unit 220 may be combined into a communication unit.

[0065] The setting unit 230 stores various setting information received by the receiving unit 220 from the base station 10 or the terminal 20 in the storage device, and reads it out from the storage device as needed. In addition, the setting unit 230 also stores preset setting information. The content of the setting information is, for example, information required for synchronization.

[0066] As described in the embodiments, the control unit 240 performs control related to synchronization. The functional unit related to signal transmission in the control unit 240 may be included in the transmitting unit 210, and the functional unit related to signal reception in the control unit 240 may be included in the receiving unit 220.

[0067] (Hardware Structure)

[0068] The block diagrams ( Figure 7 and Figure 8 ) used in the description of the above embodiments show blocks in terms of functions. These functional blocks (structural parts) are implemented by any combination of at least one of hardware and software. In addition, there is no particular limitation on the implementation method of each functional block. That is, each functional block may be implemented using a single device physically or logically combined, or two or more physically or logically separated devices may be directly or indirectly (e.g., using wired, wireless, etc.) connected and these multiple devices may be used to implement it. The functional block may also be implemented by combining software with the above-mentioned single device or the above-mentioned multiple devices.

[0069] Functionally, it has functions such as judging, deciding, determining, calculating, computing, processing, deriving, investigating, searching, confirming, receiving, sending, outputting, accessing, solving, selecting, choosing, establishing, comparing, imagining, expecting, regarding as, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating (mapping), assigning, etc., but not limited thereto. For example, a functional block (structural part) that enables sending to function is called a transmitting unit or a transmitter. In short, as described above, there is no particular limitation on the implementation method.

[0070] For example, the base station 10, the terminal 20, etc. in an embodiment of the present disclosure can also function as a computer that processes the wireless communication method of the present disclosure. Figure 9 FIG. is an example showing the hardware structure of the base station 10 and the terminal 20 in an embodiment of the present disclosure. Physically, the above-mentioned base station 10 and terminal 20 can also be 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.

[0071] In addition, in the following description, the term "device" can be replaced with "circuit", "equipment (device)", "unit", etc. The hardware structure of the base station 10 and the terminal 20 can be configured to include one or more of the illustrated devices, or can also be configured not to include some of the devices.

[0072] Each function in the base station 10 and the terminal 20 is implemented by the following method: a predetermined software (program) is read into hardware such as the processor 1001 and the storage device 1002, so that the processor 1001 performs operations and controls at least one of the communication of the communication device 1004 or the reading and writing of data in the storage device 1002 and the auxiliary storage device 1003.

[0073] The processor 1001, for example, operates the operating system to control the entire computer. The processor 1001 can also be composed of a central processing unit (CPU: Central Processing Unit) including an interface with peripheral devices, a control device, an arithmetic device, registers, etc. For example, the above-mentioned control unit 140, control unit 240, etc. can also be implemented by the processor 1001.

[0074] In addition, the processor 1001 reads out a program (program code), software module, data, etc. from at least one of the auxiliary storage device 1003 and the communication device 1004 to the storage device 1002, and executes various processes accordingly. As the program, a program that causes a computer to execute at least a part of the operations described in the above-described embodiments is used. For example, Figure 7 The control unit 140 of the base station 10 shown can also be implemented by a control program stored in the storage device 1002 and operating in the processor 1001. In addition, for example, Figure 8 The control unit 240 of the terminal 20 shown can also be implemented by a control program stored in the storage device 1002 and operating in the processor 1001. Regarding the above-described various processes, although it has been described that the above-described various processes are executed by one processor 1001, the above-described various processes can also be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 can also be installed by one or more chips. In addition, the program can also be transmitted from a network via a telecommunication line.

[0075] The storage device 1002 is a computer-readable recording medium, and can be constituted by at least one of, for example, a ROM (Read Only Memory), an EPROM (Erasable Programmable ROM), an EEPROM (Electrically Erasable Programmable ROM), a RAM (Random Access Memory), etc. The storage device 1002 can also be referred to as a register, a cache, a main memory (main storage device), etc. The storage device 1002 can store a program (program code), a software module, etc. that can be executed in order to implement the communication method according to one embodiment of the present disclosure.

[0076] The auxiliary storage device 1003 is a computer-readable recording medium, and can be constituted by at least one of, for example, an optical disc such as a CD-ROM (Compact Disc ROM), a hard disk drive, a floppy disk, a magneto-optical disc (for example, a compact disc, a digital versatile disc, a Blu-ray (registered trademark) disc, a smart card, a flash memory (for example, a card, a stick, a key drive (Key drive)), a Floppy (registered trademark) disk, a magnetic stripe, etc. The above-described recording medium can be, for example, a database, a server, and other appropriate media including at least one of the storage device 1002 and the auxiliary storage device 1003.

[0077] The communication device 1004 is hardware (a transceiver device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as a network device, a network controller, a network card, a communication module, etc. For example, the communication device 1004 may also be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc. to implement at least one of frequency-division duplexing (FDD: Frequency Division Duplex) and time-division duplexing (TDD: Time Division Duplex). For example, a transceiver antenna, an amplifier unit, a transceiver unit, a transmission path interface, etc. may also be implemented by the communication device 1004. The transceiver unit may also be physically or logically separately installed by a transmission unit and a reception unit.

[0078] 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 an input from the outside. The output device 1006 is an output device (e.g., a display, a speaker, an LED lamp, etc.) that performs an output to the outside. In addition, the input device 1005 and the output device 1006 may also be integrally formed (e.g., a touch panel).

[0079] 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 for each device.

[0080] In addition, the base station 10 and the terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP: Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), an FPGA (Field Programmable Gate Array), etc., and a part or all of each functional block may also be implemented by this hardware. For example, the processor 1001 may also be implemented using at least one of these hardwares.

[0081] (Summary of the Embodiment)

[0082] As described above, according to an embodiment of the present invention, there is provided a terminal having: a reception unit that receives information related to a reference signal; and a control unit that uses the reference signal in an RRC (Radio Resource Control) idle state or an RRC inactive state based on the information.

[0083] According to the above structure, even when in the RRC idle state or the RRC inactive state, the terminal 20 can increase the time domain positions capable of synchronization and perform highly accurate time synchronization and / or frequency synchronization by obtaining information related to the TRS / CSI-RS and using the TRS / CSI-RS. That is, in a wireless communication system, the time domain positions capable of synchronization can be increased.

[0084] The receiving unit may also receive the information related to the reference signal in the RRC idle state or the RRC inactive state. According to this structure, even when in the RRC idle state or the RRC inactive state, the terminal 20 can increase the time domain positions capable of synchronization and perform highly accurate time synchronization and / or frequency synchronization by obtaining information related to the TRS / CSI-RS and using the TRS / CSI-RS.

[0085] The information may also include the relative position of the reference signal with respect to the resource associated with paging, or the relative position of the reference signal with respect to the synchronization signal. According to this structure, even when in the RRC idle state or the RRC inactive state, the terminal 20 can efficiently obtain information related to the TRS / CSI-RS.

[0086] The control unit may also assume that the resource associated with paging or the synchronization signal "notified of the relative position with respect to the reference signal" and the reference signal are QCL (quasi co-location). According to this structure, even when in the RRC idle state or the RRC inactive state, the terminal 20 can efficiently obtain QCL information related to the TRS / CSI-RS.

[0087] The receiving unit may also receive the information related to the reference signal in the RRC connected state. According to this structure, even when in the RRC idle state or the RRC inactive state, the terminal 20 can use the information related to the TRS / CSI-RS obtained in the RRC connected state.

[0088] In addition, according to an embodiment of the present invention, there is provided a communication method executed by a terminal, wherein the terminal performs the following steps: a receiving step of receiving information related to a reference signal; and a control step of using the reference signal in the RRC (Radio Resource Control) idle state or the RRC inactive state according to the information.

[0089] According to the above structure, even when the terminal 20 is in the RRC idle state or the RRC inactive state, it can increase the time domain positions that can be synchronized and perform highly accurate time synchronization and / or frequency synchronization by obtaining information related to the TRS / CSI-RS and using the TRS / CSI-RS. That is, in a wireless communication system, it is possible to increase the time domain positions that can be synchronized.

[0090] (Supplement of the Embodiment)

[0091] The embodiments of the present invention have been described above, but the disclosed invention is not limited to such embodiments, and those skilled in the art should understand various variations, modifications, alternatives, substitution examples, etc. Specific numerical examples have been used to facilitate the understanding of the invention, but these numerical values are merely examples and any appropriate arbitrary values can be used as long as not specifically indicated. The distinction of the items in the above description is not essential for the present invention, and the matters described in two or more items can be combined as needed, or the matters described in one item can be applied to the matters described in another item (as long as there is no contradiction). The boundaries of the functional units or processing units in the functional block diagram do not necessarily correspond to the boundaries of physical components. The operations of multiple functional units can be performed by one physical component, or the operation of one functional unit can be performed by multiple physical components. Regarding the processing procedures described in the embodiments, the order of processing can be switched without contradiction. For the convenience of explaining the processing, the base station 10 and the terminal 20 are described using functional block diagrams, but such devices can also be implemented by hardware, software, or a combination thereof. The software that operates through the processor of the base station 10 according to the embodiments of the present invention and the software that operates through the processor of the terminal 20 according to the embodiments of the present invention can also be stored in a random access memory (RAM), a flash memory, a read-only memory (ROM), an EPROM, an EEPROM, a register, a hard disk drive (HDD), a removable disk, a CD-ROM, a database, a server, and other appropriate arbitrary storage media, respectively.

[0092] In addition, the notification of information is not limited to the forms / embodiments described in the present disclosure, and other methods can also be used. For example, the notification of information can be implemented through physical layer signaling (e.g., DCI (Downlink Control Information), UCI (Uplink Control Information)), high layer signaling (e.g., RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling, broadcast information (MIB (Master Information Block), SIB (System Information Block)), other signals, or a combination thereof. In addition, RRC signaling can also be referred to as an RRC message. For example, it can also be an RRC Connection Setup message, an RRC Connection Reconfiguration message, etc.

[0093] Each of the forms / embodiments described in the present disclosure can also be applied to at least one of 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), CDMA 2000, UMB (UltraMobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, UWB (Ultra-WideBand), Bluetooth (registered trademark), systems using other appropriate systems, and next-generation systems extended therefrom. In addition, multiple systems (e.g., a combination of at least one of LTE and LTE-A and 5G, etc.) can also be combined and applied.

[0094] For the processing procedures, time sequences, flows, etc. of the various forms / embodiments described in this specification, the order can be changed without contradiction. For example, for the methods described in this disclosure, the order of illustration indicates the elements of various steps, but is not limited to the specific order indicated.

[0095] In this specification, specific actions assumed to be performed by the base station 10 may sometimes be performed by its upper node depending on the situation. In a network composed of one or more network nodes having the base station 10, it is obvious that various actions performed for communicating with the terminal 20 can be performed by at least one of the base station 10 and other network nodes other than the base station 10 (for example, MME or S-GW is considered, but not limited to these). In the above, the case where there is one other network node other than the base station 10 is illustrated, but the other network nodes may also be a combination of multiple other network nodes (for example, MME and S-GW).

[0096] The information, signals, etc. described in this disclosure can be output from a higher layer (or a lower layer) to a lower layer (or a higher layer). They can also be input or output via multiple network nodes.

[0097] The input or output information, etc. can be stored in a specific location (for example, memory), or can be managed using a management table. The input or output information, etc. can be rewritten, updated, or appended. The output information, etc. can also be deleted. The input information, etc. can also be sent to other devices.

[0098] The determination in this disclosure can be made by a value represented by 1 bit (0 or 1), can also be made by a Boolean value (true or false), and can also be made by a numerical comparison (for example, comparison with a predetermined value).

[0099] For software, regardless of whether it is called software, firmware, middleware, microcode, hardware description language, or by other names, it should be broadly interpreted as referring to commands, command sets, code, code segments, program code, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, processes, functions, etc.

[0100] In addition, software, commands, information, etc. can be transmitted and received via a transmission medium. For example, in the case of transmitting software from a website, server, or other remote source using at least one of wired technologies (such as coaxial cables, fiber optic cables, twisted pairs, digital subscriber line (DSL), etc.) and wireless technologies (such as infrared rays, microwaves, etc.), at least one of these wired technologies and wireless technologies is included in the definition of the transmission medium.

[0101] The information, signals, etc. described in the present disclosure can also be represented using any one of a variety of different technologies. For example, the data, commands, instructions, information, signals, bits, symbols, chips, etc. that may be involved in the above description as a whole can be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination of these.

[0102] In addition, the terms described in the present disclosure and the terms required to understand the present disclosure can be replaced with terms having the same or similar meanings. For example, at least one of a channel and a symbol can also be a signal (signaling). In addition, a signal can also be a message. In addition, a component carrier (CC) can also be referred to as a carrier frequency, a cell, a frequency carrier, etc.

[0103] The terms "system" and "network" used in the present disclosure can be used interchangeably.

[0104] In addition, the information, parameters, etc. described in the present disclosure can be represented using absolute values, relative values with respect to a predetermined value, or can also be represented using corresponding other information. For example, wireless resources can also be indicated by an index.

[0105] The names used for the above parameters are non-restrictive in any aspect. Furthermore, the mathematical formulas, etc. using these parameters are sometimes different from the content explicitly disclosed in the present disclosure. Since various channels (such as PUCCH, PDCCH, etc.) and information elements can be identified by all appropriate names, the various names assigned to these various channels and information elements are non-restrictive in any aspect.

[0106] In the present disclosure, terms such as "Base Station (BS)", "radio base station", "base station device", "fixed station", "NodeB", "eNodeB (eNB)", "gNodeB (gNB)", "access point", "transmission point", "reception point", "transmission / reception point", "cell", "sector", "cell group", "carrier", "component carrier" can be used interchangeably. Sometimes, terms such as macro cell, small cell, femto cell, pico cell, etc. are also used to refer to the base station.

[0107] A base station can accommodate one or more (e.g., 3) 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 provide communication services through a base station subsystem (e.g., a small indoor base station (RRH: Remote Radio Head)). Terms such as "cell" or "sector" refer to a part or the whole of the coverage area of at least one of the base station and the base station subsystem that provides communication services within the coverage range.

[0108] In the present disclosure, terms such as "Mobile Station (MS)", "user terminal", "User Equipment (UE)", "terminal" can be used interchangeably.

[0109] For a mobile station, those skilled in the art sometimes also use the following terms to refer to it: subscriber station, mobile unit, subscriber unit, radio 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 appropriate terms.

[0110] At least one of the base station and the mobile station may also be referred to as a transmitting device, a receiving device, a communication device, etc. In addition, 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.), a moving body that moves in an unmanned manner (e.g., a drone, a self-driving car, etc.), or a robot (humanoid or non-humanoid). In addition, at least one of the base station and the mobile station also includes a device that does not necessarily move during the 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.

[0111] In addition, the base station in the present disclosure may be replaced by a user terminal. For example, with respect to a structure in which communication between the base station and the user terminal is replaced by communication between a plurality of terminals 20 (e.g., it may also be referred to as D2D (Device-to-Device), V2X (Vehicle-to-Everything), etc.), various forms / embodiments of the present disclosure may also be applied. In this case, it may also be configured such that the terminal 20 has the functions of the above-described base station 10. In addition, terms such as "uplink" and "downlink" may also be replaced by terms corresponding to inter-terminal communication (e.g., "side"). For example, an uplink channel, a downlink channel, etc. may also be replaced by a side channel.

[0112] Similarly, the user terminal in the present disclosure may be replaced by a base station. In this case, it may also be configured such that the base station has the functions of the above-described user terminal.

[0113] As used in this disclosure, terms such as "determining" and "deciding" sometimes include a variety of actions. For example, "determining" and "deciding" may include regarding matters that have been judged, calculated, computed, processed, derived, investigated, looked up, searched, or inquired (e.g., searched in a table, database, or other data structure), ascertained as matters that have been "determined" or "decided". In addition, "determining" and "deciding" may include regarding matters that have been received (e.g., receiving information), transmitted (e.g., transmitting information), input, output, accessed (e.g., accessing data in memory) as matters that have been "determined" or "decided". In addition, "determining" and "deciding" may include regarding matters that have been resolved, selected, chosen, established, compared, etc. as matters that have been "determined" or "decided". That is, "determining" and "deciding" may include matters that are regarded as having "determined" or "decided" any action. In addition, "determining (deciding)" may also be replaced by "assuming", "expecting", "considering", etc.

[0114] Terms such as "connected" and "coupled" or any variations of these terms are intended to represent all direct or indirect connections or couplings between two or more elements, and may include cases where there is one or more intermediate elements between the two elements that are "connected" or "coupled" to each other. The coupling or connection between elements may be a physical coupling or connection, a logical coupling or connection, or a combination of these. For example, "access" may be used to replace "connected". In the context of this disclosure, it can be considered that two elements are "connected" or "coupled" to each other using at least one of one or more wires, cables, and printed electrical connections, and as some non-limiting and non-inclusive examples, electromagnetic energy having wavelengths in the radio frequency domain, microwave region, and optical (both visible and invisible) region is used to "connect" or "couple" to each other.

[0115] A reference signal can be abbreviated as RS (Reference Signal), or can be called a pilot according to the applied standard.

[0116] In the present disclosure, the description such as "according to" does not mean "only according to" unless otherwise clearly described. In other words, the description such as "according to" means both "only according to" and "at least according to".

[0117] Any reference to elements using terms such as "first", "second", etc. used in the present disclosure does not entirely limit the quantity or order of these elements. These terms can be used in the present disclosure as a simple method for distinguishing between two or more elements. Therefore, the reference to the first element and the second element does not mean that only two elements can be adopted or that the first element must precede the second element in any form.

[0118] The "unit" in the structure of each of the above devices can also be replaced with a "section", "circuit", "equipment", etc.

[0119] When the terms "include", "including" and their variants are used in the present disclosure, these terms mean inclusive in the same way as the term "comprising". And, the term "or" used in the present disclosure does not refer to exclusive or.

[0120] A radio frame can be composed of one or more frames in the time domain. In the time domain, each of the one or more frames can be called a subframe. A subframe can be further composed of one or more time slots in the time domain. A subframe can also have a fixed time length (e.g., 1 ms) independent of the numerology.

[0121] The numerology can be communication parameters applied to at least one of transmission and reception of a certain signal or channel. The numerology can represent, for example, at least one of subcarrier spacing (SCS: SubCarrier Spacing), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI: Transmission Time Interval), number of symbols per TTI, radio frame structure, specific filtering processing performed by the transceiver in the frequency domain, specific windowing processing performed by the transceiver in the time domain, etc.

[0122] A time slot can be composed of one or more symbols (such as OFDM (Orthogonal Frequency Division Multiplexing) symbols, SC-FDMA (Single Carrier Frequency Division Multiple Access) symbols, etc.) in the time domain. A time slot can be a time unit based on a parameter set.

[0123] A time slot can contain multiple mini-slots. Each mini-slot can be composed of one or more symbols in the time domain. In addition, a mini-slot can also be referred to as a sub-slot. A mini-slot can be composed of a smaller number of symbols than a time slot. The PDSCH (or PUSCH) transmitted in units of time larger than a mini-slot can be called PDSCH (or PUSCH) mapping type A. The PDSCH (or PUSCH) transmitted using a mini-slot can be called PDSCH (or PUSCH) mapping type B.

[0124] A radio frame, a sub-frame, a time slot, a mini-slot, and a symbol all represent time units when transmitting signals. A radio frame, a sub-frame, a time slot, a mini-slot, and a symbol can be respectively referred to by corresponding other names.

[0125] For example, 1 sub-frame can also be referred to as a transmission time interval (TTI: Transmission Time Interval), multiple consecutive sub-frames can also be referred to as a TTI, 1 time slot or 1 mini-slot can also be referred to as a TTI. That is, at least one of a sub-frame and a TTI can be a sub-frame (1 ms) in the existing LTE, or a period shorter than 1 ms (for example, 1 - 13 symbols), or a period longer than 1 ms. In addition, the unit representing a TTI can be referred to not as a sub-frame, but as a time slot, a mini-slot, etc.

[0126] Here, a TTI is, for example, the minimum time unit for scheduling in wireless communication. For example, in an LTE system, a base station performs scheduling to allocate radio resources (such as the bandwidth and transmission power that can be used in each terminal 20) to each terminal 20 in units of a TTI. In addition, the definition of a TTI is not limited to this.

[0127] A TTI can be the transmission time unit for data packets (transport blocks), code blocks, codewords, etc. after channel coding, or the processing unit for scheduling, link adaptation, etc. In addition, when a TTI is given, the actual time interval (such as the number of symbols) to which a transport block, a code block, a codeword, etc. are mapped can be shorter than the TTI.

[0128] In addition, when 1 time slot or 1 mini time slot is referred to as a TTI, more than one TTI (i.e., more than one time slot or more than one mini time slot) can constitute the minimum time unit for scheduling. Furthermore, the number of time slots (number of mini time slots) that constitute the minimum time unit for scheduling can be controlled.

[0129] A TTI having a time length of 1 ms can also be referred to as a normal TTI (TTI in LTE Rel.8 - 12), a normal TTI, a long TTI, a normal subframe, a long subframe, a time slot, etc. A TTI shorter than a normal TTI can be called a shortened TTI, a short TTI, a partial or fractional TTI, a shortened subframe, a short subframe, a mini time slot, a sub - time slot, a time slot, etc.

[0130] In addition, for a long TTI (e.g., a normal TTI, a subframe, etc.), it can be replaced with a TTI having a time length exceeding 1 ms, and for a short TTI (e.g., a shortened TTI, etc.), it can be replaced with a TTI having a TTI length less than that of the long TTI and having a TTI length of 1 ms or more.

[0131] A resource block (RB) is a resource allocation unit in the time domain and the frequency domain. In the frequency domain, it can contain one or more consecutive sub - carriers. The number of sub - carriers contained in an RB can be the same regardless of the parameter set, for example, it can be 12. The number of sub - carriers contained in an RB can also be determined according to the parameter set.

[0132] Furthermore, the time domain of an RB can contain one or more symbols and can be the length of 1 time slot, 1 mini time slot, 1 subframe, or 1 TTI. 1 TTI, 1 subframe, etc. can be composed of one or more resource blocks respectively.

[0133] In addition, one or more RBs can be referred to as a physical resource block (PRB), a sub - carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, etc.

[0134] Furthermore, a resource block can be composed of one or more resource elements (RE). For example, 1 RE can be a radio resource area of 1 sub - carrier and 1 symbol.

[0135] A bandwidth part (BWP) (which may be referred to as a partial bandwidth or the like) may represent a subset of consecutive common resource blocks (RB) used for a certain parameter set in a certain carrier. Here, the common RB may be determined by the index of the RB based on the common reference point of the carrier. The PRB may be defined in a certain BWP and numbered within that BWP.

[0136] The BWP may include a BWP for UL (UL BWP) and a BWP for DL (DL BWP). One or more BWPs may be set for a UE within one carrier.

[0137] At least one of the set BWPs may be active, and it may not be assumed that the UE transmits and receives a predetermined signal / channel outside the active BWP. In addition, in the present disclosure, “cell”, “carrier”, etc. may be replaced with “BWP”.

[0138] The structures such as the above-mentioned radio frames, subframes, time slots, mini time slots, and symbols are merely examples. For example, the number of subframes included in a radio frame, the number of time slots per subframe or radio frame, the number of mini time slots included in a time slot, the number of symbols included in a time slot or mini time slot, the number of RBs, the number of subcarriers included in an RB, and the number of symbols, symbol length, cyclic prefix (CP) length, etc. within a TTI may be changed in various ways.

[0139] In the present disclosure, for example, in cases where articles are added through translation such as a, an, and the in English, the present disclosure may also include cases where the nouns following these articles are in the plural form.

[0140] In the present disclosure, an expression such as “A is different from B” may also mean “A and B are mutually different”. In addition, this expression may also mean “A and B are each different from C”. Expressions such as “separation” and “combination” may be interpreted in the same way as “different”.

[0141] Each form / embodiment described in the present disclosure may be used alone, may be combined, or may be switched according to execution. In addition, the notification of predetermined information is not limited to being explicit (for example, notification of “is X”), and may also be implicit (for example, without notification of the predetermined information).

[0142] In addition, in the present disclosure, TRS / CSI-RS is an example of a reference signal. SSB is an example of a synchronization signal.

[0143] As described above, the present disclosure has been described in detail. However, for those skilled in the art, it should be clear that the present disclosure is not limited to the embodiments described in the present disclosure. The present disclosure can be implemented in the form of modifications and changes without departing from the gist and scope of the present disclosure determined by the claims. Therefore, the purpose of the description of the present disclosure is to illustrate, and it has no restrictive meaning for the present disclosure.

[0144] Reference Numeral Description

[0145] 10: Base Station;

[0146] 110: Transmitting Unit;

[0147] 120: Receiving Unit;

[0148] 130: Setting Unit;

[0149] 140: Control Unit;

[0150] 20: Terminal;

[0151] 210: Transmitting Unit;

[0152] 220: Receiving Unit;

[0153] 230: Setting Unit;

[0154] 240: Control Unit;

[0155] 1001: Processor;

[0156] 1002: Storage Device;

[0157] 1003: Auxiliary Storage Device;

[0158] 1004: Communication Device;

[0159] 1005: Input Device;

[0160] 1006: Output Device.

Claims

1. A terminal, comprising: a receiving unit that receives information related to a Tracking Reference Signal (TRS) from a base station in a Radio Resource Control (RRC) idle state or an RRC inactive state; and a control unit that determines a time position based on the period and offset of the TRS and a position of a Resource Block (RB) according to the information, wherein the receiving unit receives the TRS at the time position and the RB position in the RRC idle state or the RRC inactive state.

2. A communication method performed by a terminal, wherein, The communication method has the following steps: In the radio resource control idle state, i.e., the RRC idle state, or the radio resource control inactive state, i.e., the RRC inactive state, receive information related to the tracking reference signal, i.e., the TRS, from the base station; Based on the information, determine the time position based on the period and offset of the TRS, and the position of the resource block, i.e., the RB; And In the RRC idle state or the RRC inactive state, receive the TRS at the time position and the position of the RB.

3. A wireless communication system including a terminal and a base station, wherein, The base station sends information related to the tracking reference signal, i.e., the TRS; The terminal receives information related to the TRS in the radio resource control idle state, i.e., the RRC idle state, or the radio resource control inactive state, i.e., the RRC inactive state; The terminal determines the time position based on the period and offset of the TRS, and the position of the resource block, i.e., the RB, according to the information; The terminal receives the TRS at the time position and the position of the RB in the RRC idle state or the RRC inactive state.

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