Method and apparatus for transmitting and receiving low power wake-up signal

Abstract

An operating method of a terminal comprises the steps of: receiving configuration information about LP-WUS from a base station; when the terminal is in a sleep state, performing an operation of monitoring the LP-WUS in LP-WUS occasion(s) configured according to the configuration information about the LP-WUS; and switching to an active state when the LP-WUS is detected, wherein the LP-WUS occasion(s) are configured independently of a C-DRX on-duration, and the terminal may perform PDCCH monitoring in the active state.

Description

Method and device for transmitting and receiving low-power wake-up signals

[0001] The present invention relates to a low-power consumption operation method in a mobile communication system, and more particularly, to a method and device for transmitting and receiving a low-power wake-up signal.

[0002] With the advancement of information and communication technology, various wireless communication technologies are being developed. Representative wireless communication technologies include LTE (long term evolution) and NR (new radio), both of which are defined by the 3rd generation partnership project (3GPP) standards. LTE can be one of the 4th generation (4G) wireless communication technologies, and NR can be one of the 5th generation (5G) wireless communication technologies.

[0003] To handle the rapidly increasing amount of wireless data following the commercialization of 4G communication systems (e.g., communication systems supporting LTE), 5G communication systems (e.g., communication systems supporting NR) that use higher frequency bands (e.g., frequency bands higher than 6 GHz) than the frequency bands of 4G communication systems (e.g., frequency bands below 6 GHz) are being considered. 5G communication systems can support enhanced Mobile Broadband (eMBB), Ultra-Reliable and Low Latency Communication (URLLC), and massive Machine Type Communication (mMTC).

[0004] 3GPP is standardizing WUR (Wake-up Radio) and LP-WUS (Low Power Wake-up Signal). WUR and LP-WUS can be used to minimize energy consumption in devices targeting low-power operation. WUR utilizes a low-power radio module separate from the main radio (MR) module to enable devices to wake up by receiving a specific signal even when inactive. LP-WUS serves as a wake-up signal for low-power devices in 5G NR environments. Its low frequency band and simple signal structure can improve energy efficiency and provide long battery life. Both technologies play a crucial role in applications such as the Internet of Things (IoT) and massive machine-to-machine (mMTC), enabling efficient use of network resources and extended device life. Further discussion is needed regarding specific LP-WUS transmission and reception methods and WUR operation methods.

[0005] An object of the present invention to solve the above problems is to provide a device for a method of transmitting and receiving a low power wake-up signal (LP-WUS) in a mobile communication system.

[0006] According to embodiments of the present invention for achieving the above object, a method of a terminal includes: receiving configuration information of a low-power wake-up signal (LP-WUS) from a base station; performing an operation of monitoring LP-WUS in LP-WUS occasion(s) configured according to the configuration information of the LP-WUS when the terminal is in a sleep state; and switching to an active state when the LP-WUS is detected, wherein the LP-WUS occasion(s) are configured independently of a connected discontinuous reception (C-DRX) on-duration, and the terminal can perform physical data control channel (PDCCH) monitoring in the active state.

[0007] The configuration information of the above LP-WUS is received through the main radio (MR) module of the terminal, and the LP-WUS can be monitored through the wake-up radio (WUR) module of the terminal.

[0008] The LP-WUS ocasion(s) may be set at predetermined intervals within and outside the C-DRX on-duration, or may be set at predetermined offsets from the start of the C-DRX on-duration.

[0009] Information about the above-described predetermined cycle may be included in the configuration information of the LP-WUS.

[0010] The above terminal can monitor the LP-WUS in the LP-WUS ocasion(s) set outside the C-DRX on-duration and the LP-WUS ocasion(s) set within the C-DRX on-duration.

[0011] The above LP-WUS can be composed of an OOK (on-off shift keying) sequence or an OFDM-overlaid sequence.

[0012] A timer having a predetermined value is started at the point in time when the terminal transitions to the active state, and when the timer expires, the terminal transitions from the active state to the sleep state, and the timer may be a separate timer from a timer defining C-DRX on-duration.

[0013] The method further includes a step of transmitting a capability report to the base station, wherein the capability report may include information about a time required for the terminal to transition from the sleep state to the active state.

[0014] If the terminal is configured to perform periodic RSRP (reference signal received power) and / or CSI (channel state information) reporting, the terminal may perform the periodic RSRP and / or CSI reporting even in the sleep state.

[0015] The terminal may activate or deactivate the operation of monitoring the LP-WUS based on the measurement result of the channel status or signaling from the base station.

[0016] The signaling is performed based on at least one of a DCI (downlink control information), a MAC-CE (medium access control-control element), or an RRC (radio resource control) message, and when the signaling is received, the terminal can transmit a confirmation message for the signaling to the base station.

[0017] According to embodiments of the present invention for achieving the above object, a method of a base station includes: a step of transmitting configuration information of a low-power wake-up signal (LP-WUS) to a terminal; and a step of performing an operation of transmitting an LP-WUS to the terminal in LP-WUS occasion(s) configured according to the configuration information of the LP-WUS when the terminal is in a sleep state, wherein when the terminal detects the LP-WUS, the terminal is switched to an active state, and the LP-WUS occasion(s) are configured independently of a connected discontinuous reception (C-DRX) on-duration, and the LP-WUS can enable the terminal to perform physical data control channel (PDCCH) monitoring in the active state.

[0018] The LP-WUS ocasion(s) may be set at predetermined intervals within and outside the C-DRX on-duration, or may be set at predetermined offsets from the start of the C-DRX on-duration.

[0019] Information about the above-described predetermined cycle may be included in the configuration information of the LP-WUS.

[0020] The above terminal can monitor the LP-WUS in the LP-WUS ocasion(s) set outside the C-DRX on-duration and the LP-WUS ocasion(s) set within the C-DRX on-duration.

[0021] The method further includes a step of receiving a capability report from the terminal, wherein the capability report may include information about a time required for the terminal to transition from the sleep state to the active state.

[0022] According to embodiments of the present invention for achieving the above object, a terminal includes: at least one processor; a main radio (MR) module; and a wake-up radio (WUR) module, wherein the at least one processor is configured to perform: receiving configuration information of a low-power wake-up signal (LP-WUS) from a base station through the main radio module; performing an operation of monitoring LP-WUS in LP-WUS occasion(s) configured according to the configuration information of the LP-WUS through the wake-up radio module when the terminal is in a sleep state; and performing a step of switching to an active state when the LP-WUS is detected, wherein the LP-WUS occasion(s) are configured independently of a connected discontinuous reception (C-DRX) on-duration, and the terminal can perform physical data control channel (PDCCH) monitoring in the active state.

[0023] The LP-WUS ocasion(s) may be set at predetermined intervals within and outside the C-DRX on-duration, or may be set at predetermined offsets from the start of the C-DRX on-duration.

[0024] The above terminal can monitor the LP-WUS in the LP-WUS ocasion(s) set outside the C-DRX on-duration and the LP-WUS ocasion(s) set within the C-DRX on-duration through the wake-up radio module.

[0025] The at least one processor may enable the terminal to activate or deactivate an operation of monitoring the LP-WUS based on a measurement result of a channel state or signaling from the base station.

[0026] According to embodiments of the present invention, a terminal can appropriately receive LP-WUS using LP-WUR. In particular, by configuring LP-WUS occasion(s) in conjunction with C-DRX settings or configuring LP-WUS occasion(s) independently of C-DRX settings, the existing C-DRX operation can be supplemented to obtain a power saving effect while performing smooth transmission and reception operations. In addition, embodiments of the present invention provide various configuration methods for LP-WUS monitoring operation and activation / deactivation methods of the LP-WUS monitoring operation, so that the LP-WUS monitoring operation of a terminal in a mobile communication system can be appropriately configured and controlled.

[0027] Figure 1 is a conceptual diagram illustrating a first embodiment of a communication system.

[0028] Figure 2 is a block diagram illustrating a first embodiment of a communication node constituting a communication system.

[0029] Figure 3 is a conceptual diagram illustrating a first embodiment of a type 1 frame structure.

[0030] Figure 4 is a conceptual diagram illustrating a first embodiment of a type 2 frame structure.

[0031] FIG. 5 is a conceptual diagram illustrating a first embodiment of a method for transmitting an SS / PBCH block in a communication system.

[0032] FIG. 6 is a conceptual diagram illustrating a first embodiment of an SS / PBCH block in a communication system.

[0033] Fig. 7 is a conceptual diagram illustrating a second embodiment of a method for transmitting an SS / PBCH block in a communication system.

[0034] Figure 8 is a conceptual diagram for explaining the time domain transmission positions of SSBs according to the subcarrier spacing and L.

[0035] Figure 9 is a conceptual diagram illustrating one example for indicating where SSB is actually transmitted via RMSI in the FR2 band.

[0036] FIG. 10a is a conceptual diagram illustrating RMSI CORESET mapping pattern #1 in a communication system, FIG. 10b is a conceptual diagram illustrating RMSI CORESET mapping pattern #2 in a communication system, and FIG. 10c is a conceptual diagram illustrating RMSI CORESET mapping pattern #3 in a communication system.

[0037] Figures 11a to 11c are drawings for explaining examples of various settings of Type 0 CSS slots corresponding to SSB indices.

[0038] FIG. 12 is a conceptual diagram illustrating embodiments of a method for multiplexing a control channel and a data channel in sidelink communication.

[0039] Figure 13 is a conceptual diagram for explaining full-duplex communication in the same band.

[0040] FIG. 14 is a conceptual diagram illustrating an embodiment for explaining a method for multiplexing uplink signals and downlink signals in full-duplex communication.

[0041] FIG. 15 is a conceptual diagram illustrating Option 1, in which LP-WUS replaces Rel-16 DCP in duty-cycle mode according to one embodiment of the present invention.

[0042] Figures 16a to 16c are conceptual diagrams for explaining Option 2 according to one embodiment of the present invention.

[0043] Figure 17 is a conceptual diagram for explaining Option 3 according to one embodiment of the present invention.

[0044] FIG. 18a and FIG. 18b are conceptual diagrams illustrating a combination of Option 1 and Option 3 (more specifically, Option 3-B) according to one embodiment of the present invention.

[0045] FIG. 19a and FIG. 19b are conceptual diagrams illustrating Option 4 according to one embodiment of the present invention.

[0046] FIG. 20 is a conceptual diagram for explaining an operation in which a terminal performs uplink transmission while performing LP-WUS monitoring according to one embodiment of the present invention.

[0047] The present invention is susceptible to various modifications and embodiments. Specific embodiments are illustrated and described in detail in the drawings. However, this is not intended to limit the present invention to specific embodiments, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention.

[0048] While terms such as "first" and "second" may be used to describe various components, these components should not be limited by these terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of the present invention, a first component could be referred to as a "second component," and similarly, a second component could also be referred to as a "first component." The term "and / or" encompasses any combination of multiple related items described herein or any one of multiple related items described herein.

[0049] In the embodiments of the present application, “at least one of A and B” may mean “at least one of A or B” or “at least one of combinations of one or more of A and B.” Furthermore, in the embodiments of the present application, “at least one of A and B” may mean “at least one of A or B” or “at least one of combinations of one or more of A and B.”

[0050] In the embodiments of the present application, (re)transmission may mean “transmission,” “retransmission,” or “transmission and retransmission,” (re)setting may mean “setting,” “resetting,” or “setting and resetting,” (re)connection may mean “connection,” “reconnection,” or “connection and reconnection,” and (re)connection may mean “connection,” “reconnection,” or “connection and reconnection.”

[0051] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

[0052] The terminology used in this application is only used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, it should be understood that the terms "comprise" or "have" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0053] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0054] Hereinafter, with reference to the attached drawings, preferred embodiments of the present invention will be described in more detail. In order to facilitate an overall understanding in describing the present invention, identical reference numerals will be used for identical components in the drawings, and redundant descriptions of identical components will be omitted.

[0055] A communication system to which embodiments of the present invention are applied will be described. The communication system to which embodiments of the present invention are applied is not limited to the scope described below, and embodiments of the present invention can be applied to various communication systems. Here, the term "communication system" can be used interchangeably with "communication network."

[0056] Figure 1 is a conceptual diagram illustrating a first embodiment of a communication system.

[0057] Referring to FIG. 1, the communication system (100) may include a plurality of communication nodes (110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5, 130-6). In addition, the communication system (100) may further include a core network (e.g., a serving-gateway (S-GW), a packet data network (PDN)-gateway (P-GW), a mobility management entity (MME)). If the communication system (100) is a 5G communication system (e.g., a new radio (NR) system), the core network may include an access and mobility management function (AMF), a user plane function (UPF), a session management function (SMF), etc.

[0058] A plurality of communication nodes (110 to 130) can support a communication protocol (e.g., LTE communication protocol, LTE-A communication protocol, NR communication protocol, etc.) specified in the 3GPP (3rd generation partnership project) standard. The plurality of communication nodes (110 to 130) may support CDMA (code division multiple access) technology, WCDMA (wideband CDMA) technology, TDMA (time division multiple access) technology, FDMA (frequency division multiple access) technology, OFDM (orthogonal frequency division multiplexing) technology, Filtered OFDM technology, CP (cyclic prefix)-OFDM technology, DFT-s-OFDM (discrete Fourier transform-spread-OFDM) technology, OFDMA (orthogonal frequency division multiple access) technology, SC (single carrier)-FDMA technology, NOMA (non-orthogonal multiple access) technology, GFDM (generalized frequency division multiplexing) technology, FBMC (filter bank multi-carrier) technology, UFMC (universal filtered multi-carrier) technology, SDMA (space division multiple access) technology, etc. Each of the plurality of communication nodes may have the following structure.

[0059] Figure 2 is a block diagram illustrating a first embodiment of a communication node constituting a communication system.

[0060] Referring to FIG. 2, a communication node (200) may include at least one processor (210), a memory (220), and a transmission / reception device (230) that is connected to a network and performs communication. In addition, the communication node (200) may further include an input interface device (240), an output interface device (250), a storage device (260), etc. Each component included in the communication node (200) may be connected by a bus (270) and communicate with each other.

[0061] However, each component included in the communication node (200) may be connected through an individual interface or individual bus centered around the processor (210), rather than a common bus (270). For example, the processor (210) may be connected to at least one of a memory (220), a transmission / reception device (230), an input interface device (240), an output interface device (250), and a storage device (260) through a dedicated interface.

[0062] The processor (210) can execute program commands stored in at least one of the memory (220) and the storage device (260). The processor (210) may refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor in which methods according to embodiments of the present invention are performed. Each of the memory (220) and the storage device (260) may be configured with at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory (220) may be configured with at least one of a read-only memory (ROM) and a random access memory (RAM).

[0063] Referring again to FIG. 1, the communication system (100) may include a plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) and a plurality of terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6). Each of the first base station (110-1), the second base station (110-2), and the third base station (110-3) may form a macro cell. Each of the fourth base station (120-1) and the fifth base station (120-2) may form a small cell. The fourth base station (120-1), the third terminal (130-3), and the fourth terminal (130-4) may be within the cell coverage of the first base station (110-1). The second terminal (130-2), the fourth terminal (130-4), and the fifth terminal (130-5) may be within the cell coverage of the second base station (110-2). The fifth base station (120-2), the fourth terminal (130-4), the fifth terminal (130-5), and the sixth terminal (130-6) may be within the cell coverage of the third base station (110-3). The first terminal (130-1) may be within the cell coverage of the fourth base station (120-1). The sixth terminal (130-6) may be within the cell coverage of the fifth base station (120-2).

[0064] Here, each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may be referred to as a NodeB (NB), an evolved NodeB (eNB), a gNB, an advanced base station (ABS), a high reliability-base station (HR-BS), a base transceiver station (BTS), a radio base station, a radio transceiver, an access point, an access node, a radio access station (RAS), a mobile multihop relay-base station (MMR-BS), a relay station (RS), an advanced relay station (ARS), a high reliability-relay station (HR-RS), a home NodeB (HNB), a home eNodeB (HeNB), a road side unit (RSU), a radio remote head (RRH), a transmission point (TP), a transmission and reception point (TRP), etc.

[0065] Each of the plurality of terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) may be referred to as a user equipment (UE), terminal equipment (TE), advanced mobile station (AMS), high reliability-mobile station (HR-MS), terminal, access terminal, mobile terminal, station, subscriber station, mobile station, portable subscriber station, node, device, on board unit (OBU), etc.

[0066] Meanwhile, each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may operate in a different frequency band or may operate in the same frequency band. Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may be connected to each other via an ideal backhaul link or a non-ideal backhaul link, and may exchange information with each other via the ideal backhaul link or the non-ideal backhaul link. Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may be connected to the core network via the ideal backhaul link or the non-ideal backhaul link. Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) can transmit a signal received from the core network to the corresponding terminal (130-1, 130-2, 130-3, 130-4, 130-5, 130-6), and can transmit a signal received from the corresponding terminal (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) to the core network.

[0067] Additionally, each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may support MIMO transmission (e.g., single user (SU)-MIMO, multi user (MU)-MIMO, massive MIMO, etc.), coordinated multipoint (CoMP) transmission, carrier aggregation (CA) transmission, transmission in an unlicensed band, device to device communication (D2D) (or, proximity services (ProSe)), Internet of Things (IoT) communication, dual connectivity (DC), etc. Here, each of the plurality of terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) can perform an operation corresponding to the base station (110-1, 110-2, 110-3, 120-1, 120-2) and an operation supported by the base station (110-1, 110-2, 110-3, 120-1, 120-2). For example, the second base station (110-2) can transmit a signal to the fourth terminal (130-4) based on the SU-MIMO scheme, and the fourth terminal (130-4) can receive a signal from the second base station (110-2) by the SU-MIMO scheme. Alternatively, the second base station (110-2) can transmit signals to the fourth terminal (130-4) and the fifth terminal (130-5) based on the MU-MIMO method, and each of the fourth terminal (130-4) and the fifth terminal (130-5) can receive signals from the second base station (110-2) based on the MU-MIMO method.

[0068] Each of the first base station (110-1), the second base station (110-2), and the third base station (110-3) can transmit a signal to the fourth terminal (130-4) based on the CoMP scheme, and the fourth terminal (130-4) can receive a signal from the first base station (110-1), the second base station (110-2), and the third base station (110-3) based on the CoMP scheme. Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) can transmit and receive a signal with terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) within its cell coverage based on the CA scheme. Each of the first base station (110-1), the second base station (110-2), and the third base station (110-3) can control D2D between the fourth terminal (130-4) and the fifth terminal (130-5), and each of the fourth terminal (130-4) and the fifth terminal (130-5) can perform D2D under the control of the second base station (110-2) and the third base station (110-3).

[0069] Meanwhile, a communication system can support three types of frame structures. The Type 1 frame structure can be applied to a frequency division duplex (FDD) communication system, the Type 2 frame structure can be applied to a time division duplex (TDD) communication system, and the Type 3 frame structure can be applied to an unlicensed band-based communication system (e.g., a licensed assisted access (LAA) communication system).

[0070] Figure 3 is a conceptual diagram illustrating a first embodiment of a type 1 frame structure.

[0071] Referring to FIG. 3, a radio frame (300) may include 10 subframes, and a subframe may include 2 slots. Accordingly, the radio frame (300) may include 20 slots (e.g., slot #0, slot #1, slot #2, slot #3, slot #18, slot #19). The length (Tf) of the radio frame (300) may be 10 ms (milliseconds), the subframe length may be 1 ms, and the slot length (Tslot) may be 0.5 ms. Here, Ts may indicate a sampling time and may be 1 / 30,720,000 s (second).

[0072] A slot may be composed of multiple OFDM symbols in the time domain and multiple resource blocks (RBs) in the frequency domain. A RB may be composed of multiple subcarriers in the frequency domain. The number of OFDM symbols constituting a slot may vary depending on the configuration of a cyclic prefix (CP). CPs can be classified into normal CPs and extended CPs. When a normal CP is used, a slot may be composed of 7 OFDM symbols, in which case a subframe may be composed of 14 OFDM symbols. When an extended CP is used, a slot may be composed of 6 OFDM symbols, in which case a subframe may be composed of 12 OFDM symbols.

[0073] Figure 4 is a conceptual diagram illustrating a first embodiment of a type 2 frame structure.

[0074] Referring to FIG. 4, a radio frame (400) may include two half frames, and a half frame may include five subframes. Therefore, a radio frame (400) may include ten subframes. The length (Tf) of the radio frame (400) may be 10 ms. The length of a half frame may be 5 ms. The length of a subframe may be 1 ms. Here, Ts may be 1 / 30,720,000 s.

[0075] The radio frame (400) may include a downlink subframe, an uplink subframe, and a special subframe. Each of the downlink subframe and the uplink subframe may include two slots. The slot length (Tslot) may be 0.5 ms. Among the subframes included in the radio frame (400), each of subframe #1 and subframe #6 may be a special subframe. For example, when the downlink-uplink switching period is 5 ms, the radio frame (400) may include two special subframes. Alternatively, when the downlink-uplink switching period is 10 ms, the radio frame (400) may include one special subframe. The special subframe may include a downlink pilot time slot (DwPTS), a guard period (GP), and an uplink pilot time slot (UpPTS).

[0076] The downlink pilot time slot can be considered a downlink period and can be used for cell search, time and frequency synchronization acquisition, channel estimation, etc. of the terminal. The guard period can be used to solve the interference problem of uplink data transmission caused by the delay in downlink data reception. In addition, the guard period can include the time required for switching from downlink data reception operation to uplink data transmission operation. The uplink pilot time slot can be used for uplink channel estimation, time and frequency synchronization acquisition, etc. The transmission of a physical random access channel (PRACH) or a sounding reference signal (SRS) can be performed in the uplink pilot time slot.

[0077] The lengths of each of the downlink pilot time slot, guard interval, and uplink pilot time slot included in the special subframe can be variably adjusted as needed. In addition, the number and location of each of the downlink subframes, uplink subframes, and special subframes included in the radio frame (400) can be changed as needed.

[0078] In a communication system, a transmission time interval (TTI) may be a basic time unit for transmitting encoded data through a physical layer. A short TTI may be used to support low-latency requirements in a communication system. The length of a short TTI may be less than 1 ms. A conventional TTI with a length of 1 ms may be referred to as a base TTI or a regular TTI. That is, a base TTI may consist of one subframe. To support transmission in a basic TTI unit, signals and channels may be configured on a subframe basis. For example, a cell-specific reference signal (CRS), a physical downlink control channel (PDCCH), a physical downlink shared channel (PDSCH), a physical uplink control channel (PUCCH), and a physical uplink shared channel (PUSCH) may exist in each subframe.

[0079] On the other hand, synchronization signals (e.g., primary synchronization signal (PSS), secondary synchronization signal (SSS)) can exist every 5 subframes, and physical broadcast channel (PBCH) can exist every 10 subframes. In addition, radio frames can be distinguished by SFN, and SFN can be used to define transmission of signals whose transmission period is longer than one radio frame (e.g., paging signals, reference signals for channel estimation, signals indicating channel state information, etc.). The period of SFN can be 1024.

[0080] In an LTE system, the PBCH may be a physical layer channel used to transmit system information (e.g., master information block (MIB)). The PBCH may be transmitted every 10 subframes. That is, the transmission period of the PBCH may be 10 ms, and the PBCH may be transmitted once in a radio frame. The same MIB may be transmitted over four consecutive radio frames, and the MIB may change after four consecutive radio frames depending on the circumstances of the LTE system. The transmission period of the same MIB may be referred to as a "PBCH TTI," and the PBCH TTI may be 40 ms. That is, the MIB may change for each PBCH TTI.

[0081] The MIB can be composed of 40 bits. Of the 40 bits that make up the MIB, 3 bits can be used to indicate the system bandwidth, 3 bits can be used to indicate information related to the physical hybrid ARQ (automatic repeat request) indicator channel (PHICH), 8 bits can be used to indicate the SFN, 10 bits can be set as reserved bits, and 16 bits can be used for the CRC (cyclic redundancy check).

[0082] The SFN that distinguishes a radio frame can be composed of a total of 10 bits (B9 to B0), and among the 10 bits, the most significant bit (MSB) 8 bits (B9 to B2) can be indicated by the PBCH (i.e., MIB). The 8 MSB bits (B9 to B2) of the SFN indicated by the PBCH (i.e., MIB) can be the same during four consecutive radio frames (i.e., PBCH TTI). The two least significant bit (LSB) bits (B1 to B0) of the SFN can change during four consecutive radio frames (i.e., PBCH TTI) and may not be explicitly indicated by the PBCH (i.e., MIB). The two LSB bits (B1 to B0) of the SFN can be implicitly indicated by a scrambling sequence for the PBCH (hereinafter, referred to as "PBCH scrambling sequence").

[0083] A gold sequence initialized with a cell ID as the PBCH scrambling sequence can be used, and the PBCH scrambling sequence can be initialized every four consecutive radio frames (i.e., PBCH TTI) according to mod(SFN,4). A PBCH transmitted in a radio frame corresponding to an SFN in which the LSB 2 bits (B1 to B0) are set to "00" can be scrambled by the gold sequence initialized with the cell ID. Thereafter, gold sequences generated according to mod(SFN,4) can be used to scramble a PBCH transmitted in a radio frame in which the LSB 2 bits (B1 to B0) of the SFN are "01", "10", and "11".

[0084] Therefore, a terminal that acquires a cell ID during the initial cell search process can implicitly find out the values ​​of the LSB 2 bits (B1 to B0) of the SFN (e.g., "00", "01", "10", "11") through the PBCH scrambling sequence during the decoding process of the PBCH (i.e., MIB). The terminal can use the LSB 2 bits (B1 to B0) of the SFN identified based on the PBCH scrambling sequence and the MSB 8 bits (B9 to B2) of the SFN indicated by the PBCH (i.e., MIB) to identify the SFN (i.e., the entire bits (B9 to B0) of the SFN).

[0085]

[0086] Evolving mobile communication networks beyond LTE must meet technical requirements to support a wider range of service scenarios, beyond the traditional focus on high transmission speeds. Recently, the International Telecommunication Union (ITU-R) defined key performance indicators (KPIs) and requirements for IMT-2020, the official name for 5G mobile communications. These can be summarized as high transmission speeds (eMBB, enhanced Mobile Broadband), low transmission latency (URLLC, Ultra Reliable Low Latency Communication), and massive machine type communication (mMTC). According to the ITU-R's anticipated schedule, the goal is to allocate frequencies for IMT-2020 in 2019 and complete international standard approval by 2020.

[0087] 3GPP is developing a 5G standard based on a new radio access technology (RAT) that meets the IMT-2020 requirements. According to 3GPP's definition, the new radio access technology is a radio access technology that is not backward compatible with existing 3GPP radio access technologies. New wireless communication systems after LTE that adopt this radio access technology are referred to as NR (New Radio) in this specification.

[0088] One of the key differences between NR and existing 3GPP systems like CDMA and LTE is its ability to utilize a wide range of frequency bands to increase transmission capacity. In this regard, the ITU-hosted World Radio Conference (WRC-15) has set the 24.25-86 GHz band as a candidate frequency band for IMT-2020 as an agenda item for the next WRC-19. 3GPP is considering bands from sub-1 GHz to 100 GHz as candidate NR bands.

[0089] Among the waveform technologies being discussed for NR, OFDM (Orthogonal Frequency Division Multiplexing), Filtered OFDM, GFDM (Generalized Frequency Division Multiplexing), FBMC (Filter Bank Multi-Carrier), and UFMC (Universal Filtered Multi-Carrier) are candidates. Although each has its own advantages and disadvantages, CP (Cyclic prefix)-based OFDM and SC-FDMA (Single Carrier-Frequency Division Multiple Access) are still effective methods for 5G systems due to their relatively low implementation complexity at the transmitter and receiver and MIMO (Multiple-Input Multiple-Output) scalability. However, in order to flexibly support various 5G usage scenarios, a method of simultaneously accommodating different waveform parameters on a single carrier without a guard band can be considered. For this purpose, Filtered OFDM or GFDM, which have a frequency spectrum with small out-of-band emissions (OOB), may be suitable.

[0090] For convenience of explanation, the present invention assumes CP-based OFDM as the waveform technology for wireless access. However, this is merely for convenience of explanation, and the various embodiments of the present invention are not limited to any specific waveform technology. Generally, the category of CP-based OFDM technologies also includes Filtered OFDM and Spread Spectrum OFDM (e.g., DFT-spread OFDM).

[0091]

[0092] The subcarrier spacing of a communication system (e.g., an OFDM-based communication system) can be determined based on factors such as carrier frequency offset (CFO). CFO can be caused by the Doppler effect, phase drift, etc., and can increase in proportion to the operating frequency. Therefore, to prevent performance degradation of the communication system due to CFO, the subcarrier spacing can increase in proportion to the operating frequency. On the other hand, as the subcarrier spacing increases, the CP overhead can increase. Therefore, the subcarrier spacing can be set based on channel characteristics according to the frequency band, radio frequency (RF) characteristics, etc.

[0093] NR systems consider various numerologies. For example, the subcarrier spacing in a communication system can be set to 15 kHz, 30 kHz, 60 kHz, or 120 kHz. The subcarrier spacing in an LTE system can be 15 kHz, while in an NR system, the subcarrier spacing can be 1, 2, 4, or 8 times the existing 15 kHz subcarrier spacing. When the subcarrier spacing increases by exponential multiples of the existing subcarrier spacing, the frame structure can be easily designed.

[0094] Communication systems can support a wide frequency band (e.g., hundreds of megahertz to tens of gigahertz). Because the diffraction and reflection characteristics of radio waves are poor in high-frequency bands, propagation loss (e.g., path loss, reflection loss, etc.) in high-frequency bands can be greater than propagation loss in low-frequency bands. Consequently, the cell coverage of a communication system supporting a high-frequency band may be less than that of a communication system supporting a low-frequency band. To address this issue, beamforming based on multiple antenna elements can be used to increase cell coverage in communication systems supporting high-frequency bands.

[0095] Beamforming methods may include digital beamforming, analog beamforming, and hybrid beamforming. In a communication system using a digital beamforming method, beamforming gain can be obtained by using multiple RF paths based on a digital precoder or codebook. In a communication system using an analog beamforming method, beamforming gain can be obtained by using analog RF devices (e.g., phase shifters, power amplifiers (PAs), variable gain amplifiers (VGAs), etc.) and antenna arrays.

[0096] Because digital beamforming requires expensive digital-to-analog converters (DACs) or analog-to-digital converters (ADCs) and transceiver units corresponding to the number of antenna elements, the complexity of antenna implementation may increase to increase beamforming gain. In communication systems using analog beamforming, since multiple antenna elements are connected to a single transceiver unit through phase shifters, the complexity of antenna implementation may not increase significantly even when the beamforming gain is increased. However, the beamforming performance of communication systems using analog beamforming may be lower than that of communication systems using digital beamforming. Furthermore, since the phase shifter in communication systems using analog beamforming is controlled in the time domain, frequency resources may not be used efficiently. Therefore, a hybrid beamforming method that combines digital and analog methods may be used.

[0097] When cell coverage is increased by using beamforming, not only the control channel and data channel of each terminal, but also the common control channel and common signal (e.g., reference signal, synchronization signal) for all terminals belonging to the cell coverage can be transmitted based on the beamforming method. When transmitting the common control channel and signal to all terminals while increasing cell coverage by applying beamforming, it is difficult to transmit the common control channel and signal to the entire cell coverage with a single transmission, and the common control channel and signal must be transmitted through multiple beams several times over a certain period of time. This transmission over multiple periods of time while switching multiple beams is called beam sweeping. When transmitting the common control channel and signal by applying beamforming, this beam sweeping operation is absolutely necessary.

[0098]

[0099] A terminal accessing the system can obtain downlink frequency / time synchronization and cell ID information using a synchronization signal, and then obtain uplink synchronization and form a radio link through a random access procedure. At this time, in the NR system, a SS / PBCH (synchronization block / physical broadcast channel) block can also be transmitted using a beam sweeping method. The SS / PBCH block can be composed of a PSS, an SSS, a PBCH, etc., and the PSS, SSS, and PBCH within the SS / PBCH block can be configured using a TDM (time division multiplexing) method. The SS / PBCH block may also be referred to as an "SS block (SSB)." One SS / PBCH block can be transmitted using N consecutive OFDM symbols. Here, N can be an integer greater than or equal to 4. The base station can periodically transmit the SS / PBCH block, and the terminal can obtain frequency / time synchronization, a cell ID, system information, etc. based on the SS / PBCH block received from the base station. SS / PBCH blocks can be transmitted as follows:

[0100] FIG. 5 is a conceptual diagram illustrating a first embodiment of a method for transmitting an SS / PBCH block in a communication system.

[0101] Referring to FIG. 5, one or more SS / PBCH blocks within an SS / PBCH block burst set may be transmitted in a beam sweeping manner. Up to L SS / PBCH blocks may be transmitted within one SS / PBCH block burst set. L may be an integer greater than or equal to 2 and may be defined in the 3GPP standard. L may vary depending on the system frequency domain. SS / PBCH blocks within an SS / PBCH block burst set may be positioned consecutively or distributedly. Consecutive SS / PBCH blocks may be referred to as an "SS / PBCH block burst." An SS / PBCH block burst set may be repeated periodically, and system information (e.g., MIB) transmitted via the PBCH of SS / PBCH blocks within an SS / PBCH block burst set may be the same. SS / PBCH block index, SS / PBCH block burst index, OFDM symbol index, slot index, etc. can be explicitly or implicitly indicated by PBCH.

[0102] FIG. 6 is a conceptual diagram illustrating a first embodiment of an SS / PBCH block in a communication system.

[0103] Referring to FIG. 6, the arrangement order within the SS / PBCH block may be "PSS *?*→? SSS →? PBCH". Within the SS / PBCH block, the PSS, SSS, and PBCH may be configured in a TDM manner. In a symbol where the SSS is located, the PBCH may be arranged in frequency resources higher than and lower than the SSS. When the maximum number of SS / PBCH blocks is 8 in a frequency band below 6 GHz, the index of the SS / PBCH block may be identified based on a demodulation reference signal (DMRS) (hereinafter referred to as "PBCH DMRS") used for demodulation of the PBCH. When the maximum number of SS / PBCH blocks is 64 in a frequency band above 6 GHz, among the 6 bits indicating the index of the SS / PBCH block, the 3 LSB bits may be identified based on the PBCH DMRS, and the remaining 3 MSB bits may be identified based on the PBCH payload.

[0104] The maximum system bandwidth supported by an NR system may be 400 MHz. The maximum bandwidth supported by a terminal may vary depending on its capabilities. Therefore, a terminal may perform an initial access procedure (e.g., an initial connection procedure) using a portion of the system bandwidth of an NR system that supports wideband. To support the access procedure for terminals that support various bandwidths, SS / PBCH blocks may be multiplexed along the frequency axis within the system bandwidth of a wideband NR system. In this case, SS / PBCH blocks may be transmitted as follows.

[0105] Fig. 7 is a conceptual diagram illustrating a second embodiment of a method for transmitting an SS / PBCH block in a communication system.

[0106] Referring to FIG. 7, a wideband component carrier (CC) may include multiple bandwidth parts (BWPs). For example, a wideband CC may include four BWPs. A base station may transmit an SS / PBCH block in each of BWPs #0 to #3 belonging to the wideband CC. A terminal may receive an SS / PBCH block in one or more BWPs among BWPs #0 to #3 and perform an initial access procedure using the received SS / PBCH block.

[0107] After detecting an SS / PBCH block, the terminal can obtain system information (e.g., remaining minimum system information (RMSI)) and perform a cell access procedure based on the system information. The RMSI can be transmitted through a PDSCH scheduled by a PDCCH. Configuration information of a CORESET (control resource set) on which a PDCCH including scheduling information of a PDSCH on which the RMSI is transmitted can be transmitted through a PBCH within the SS / PBCH block. A plurality of SS / PBCH blocks can be transmitted over the entire system bandwidth, and among the plurality of SS / PBCH blocks, one or more SS / PBCH blocks can be SS / PBCH blocks associated with an RMSI. The remaining SS / PBCH blocks may not be associated with an RMSI. An SS / PBCH block associated with an RMSI can be defined as a "cell-defining SS / PBCH block." The terminal can perform a cell search procedure and an initial access procedure using the cell-defining SS / PBCH block. SS / PBCH blocks not associated with RMSI may be used for synchronization and / or measurement procedures in the corresponding BWP. The BWP in which the SS / PBCH block is transmitted may be limited to one or more BWPs within a wide bandwidth.

[0108] RMSI can be obtained by performing "an operation of obtaining configuration information of CORESET from a SS / PBCH block (e.g., PBCH) --> an operation of detecting PDCCH based on the configuration information of CORESET --> an operation of obtaining scheduling information of PDSCH from PDCCH --> an operation of receiving RMSI via PDSCH." The transmission resource of PDCCH can be set by the configuration information of CORESET. The RMSI CORESET mapping pattern can be defined as follows. The RMSI CORESET can be a CORESET used for transmitting and receiving RMSI.

[0109] Figure 8 is a conceptual diagram for explaining the time domain transmission positions of SSBs according to the subcarrier spacing and L.

[0110] The time domain locations where SSB is transmitted can be defined differently depending on the subcarrier spacing and L value. In the symbol(s) where SSB is not transmitted within a slot, short UL transmissions such as Uplink Control Information (UCI) can be performed. In SSB transmissions with large subcarrier spacing (e.g., 120 kHz or 240 kHz SCS), a gap can be set in the middle of consecutive slots containing SSB to allow long UL transmissions such as URLLC traffic to be performed at least every 1 ms.

[0111] As in the example of FIG. 8, a gap for UL transmission may be set after 8 slots containing SSBs with a 120 kHz subcarrier spacing, and a gap for UL transmission may be set after 16 slots containing SSBs with a 240 kHz subcarrier spacing.

[0112] As described above, the transmission possible locations are set so that up to L SSB transmissions are possible within an SSB burst set, and the L value has different values ​​depending on the frequency domain. For example, in FR1, up to 4 SSB transmissions are possible between 0 and 3 GHz, up to 8 SSB transmissions are possible thereafter, and up to 64 SSB transmissions are possible in FR2. At this time, depending on the environment, the system may transmit actual SSBs at all L locations or use only some of L for actual SSB transmission. At this time, when a terminal receiving data receives data at a location where SSB transmission is possible, the terminal determines whether to rate-match the received data based on whether actual SSB transmission is performed at the location. At this time, information about the location where the SSB is actually transmitted can be transmitted to the terminal through RMSI and / or UE-specific RRC signaling. When transmitted via RMSI, when L=4 or 8, the location where the actual SSB is transmitted is indicated as '1' through bitmap information, and the location where the SSB is not transmitted is indicated as '0'. When L=64, 64 location information is transmitted in a compressed form of 16 bits. More specifically, L=64 SSBs are divided into 8 groups of 8 each, and 8 SSBs within a group are represented by 8-bit bitmaps, and each of the 8 groups is represented by an 8-bit bitmap, so that the bitmap is composed of 16 bits in total. Therefore, all groups have the same SSB transmission pattern within the group.

[0113] Figure 9 is a conceptual diagram illustrating one example for indicating where SSB is actually transmitted via RMSI in the FR2 band.

[0114] The parameter ssb-PositionsInBurst, which indicates transmission positions, consists of two parameters: inOneGroup and groupPresence, each of which consists of 8 bits. Among these, inOneGroup indicates whether each SSB within the group is transmitted using an 8-bit bitmap, and groupPresence indicates whether each group is transmitted. At this time, the groups signaled as being transmitted through groupPresence (indicated by a '1' in the 8-bit bitmap) all have SSB transmission positions with the same pattern signaled by inOneGroup. By signaling in this way, transmission positions can be signaled with 16 bits out of 64 possible SSB transmission positions, which reduces signaling overhead. However, the signaled transmission positions may differ from the actual transmission positions. For example, even if the patterns of the first and third groups in FIG. 9 are actually operated differently, this cannot be signaled. Therefore, to solve this problem, the actual transmission positions of the SSBs are additionally signaled using a 64-bit bitmap through UE-specific RRC signaling. When the information is transmitted through UE-specific RRC signaling, it is transmitted as a full bitmap regardless of the L value.

[0115] As described above, RMSI reception is achieved through a series of processes: detecting PDCCH through CORESET configuration information transmitted through PBCH, obtaining RMSI scheduling information through this, and then receiving PDSCH accordingly. At this time, the control channel resource area where PDCCH can be transmitted is set through RMSI CORESET configuration information, which can have three major patterns as follows.

[0116] FIG. 10a is a conceptual diagram illustrating RMSI CORESET mapping pattern #1 in a communication system, FIG. 10b is a conceptual diagram illustrating RMSI CORESET mapping pattern #2 in a communication system, and FIG. 10c is a conceptual diagram illustrating RMSI CORESET mapping pattern #3 in a communication system.

[0117] Referring to FIGS. 10A to 10C, one RMSI CORESET mapping pattern among RMSI CORESET mapping patterns #1 to #3 can be used, and detailed settings can be completed according to one RMSI CORESET mapping pattern. In RMSI CORESET mapping pattern #1, SS / PBCH block, CORESET (e.g., RMSI CORESET), and PDSCH (e.g., RMSI PDSCH) can be configured in a TDM manner. RMSI PDSCH can mean PDSCH on which RMSI is transmitted. In RMSI CORESET mapping pattern #2, CORESET (e.g., RMSI CORESET) and PDSCH (e.g., RMSI PDSCH) can be configured in a TDM manner, and PDSCH (e.g., RMSI PDSCH) can be configured in an SS / PBCH block and an FDM (frequency division multiplexing) manner. In RMSI CORESET mapping pattern #3, CORESET (e.g., RMSI CORESET) and PDSCH (e.g., RMSI PDSCH) can be configured in TDM manner, and CORESET (e.g., RMSI CORESET) and PDSCH (e.g., RMSI PDSCH) can be configured in SS / PBCH block and FDM manner.

[0118] In the frequency band below 6 GHz, only RMSI CORESET mapping pattern #1 can be used. In the frequency band above 6 GHz, all of RMSI CORESET mapping patterns #1, #2, and #3 can be used. The numerology of the SS / PBCH block can be different from the numerology of "RMSI CORESET and RMSI PDSCH". Here, the numerology can be subcarrier spacing. In RMSI CORESET mapping pattern #1, any combination of numerologies can be used. In RMSI CORESET mapping pattern #2, any combination of "SS / PBCH block, RMSI CORESET / PDSCH = 120 kHz, 60 kHz or 240 kHz, 120 kHz" can be used. In RMSI CORESET mapping pattern #3, the combination of "SS / PBCH block, RMSI CORESET / PDSCH = 120kHz, 120kHz" can be used.

[0119] According to the combination of the numerology of the SS / PBCH block and the numerology of the RMSI CORESET / PDSCH, one RMSI CORESET mapping pattern may be selected from RMSI CORESET mapping patterns #1-3. Configuration information of the RMSI CORESET may include tables A and B. Table A may indicate the number of RBs (resource blocks) of the RMSI CORESET, the number of symbols of the RMSI CORESET, and the offset between the RB of the SS / PBCH block (e.g., a start RB or an end RB) and the RB of the RMSI CORESET (e.g., a start RB or an end RB). Table B may indicate the number of search space sets per slot, the offset of the RMSI CORESET, and the OFDM symbol index in each of the RMSI CORESET mapping patterns. Table B may indicate information for configuring a monitoring occasion of the RMSI PDCCH. Each of Table A and Table B may be composed of multiple tables. For example, Table A may include Tables 13-1 to 13-8 as specified in TS 38.213, and Table B may include Tables 13-9 to 13-13 as specified in TS 38.213. The size of each of Table A and Table B may be 4 bits.

[0120] In case of pattern #1 among the three patterns for RMSI CORESET setting illustrated in FIGS. 10a to 10c, the terminal monitors Type 0 CSS in two consecutive slots, and the position of the start slot for Type 0 CSS monitoring is can be calculated by the following mathematical formula 1.

[0121]

[0122]

[0123] In mathematical expression 1, is a parameter indicating the subcarrier spacing. The subcarrier spacing is 15 kHz. =0 is indicated by the subcarrier spacing of 30 kHz. =1 is indicated by the subcarrier spacing of 60 kHz. =2 is indicated by the subcarrier spacing of 120 kHz. =Indicated by 3. Indicates the SSB index of the SSB received by the terminal from the base station (or the SSB transmitted by the base station to the terminal), and in case of operation in an unlicensed band, the SSB index Instead, the SSB candidate index of the SSB received by the terminal from the base station (or the SSB transmitted by the base station to the terminal) can be used. is within the radio frame Indicates the number of slots having a subcarrier spacing corresponding to and are configurable parameters for the scheduling flexibility of the base station. Specifically, when calculating the location of a Type 0 CSS slot, Indicates the offset between the SSB and Type 0 CSS slots, Determines whether there is overlap between Type 0 CSS monitoring slots when monitoring in two consecutive slots. can be set to one of the values ​​1 / 2, 1, and 2. The degree of overlap between two Type 0 CSS slots corresponding to one SSB index can be set differently.

[0124] Figures 11a to 11c are drawings for explaining examples of various settings of Type 0 CSS slots corresponding to SSB indices.

[0125] Referring to Fig. 11a, =1 / 2, the Type 0 CSS slots (e.g., slot #m, slot #m+1) corresponding to two SSB indices (e.g., SSB index #0, SSB index #1) are set to overlap completely. The Type 0 CSS slots (e.g., slot #m+1, slot #m+2) corresponding to the next two SSB indices (e.g., SSB index #2, SSB index #3) are set to overlap with the previous slots in only one slot.

[0126] Referring to Fig. 11b, If =1, the first slot of two consecutive slots corresponding to each SSB index is set to overlap the second slot of two slots corresponding to the previous SSB index.

[0127] Referring to Fig. 11c, =2, two consecutive slots corresponding to each SSB index are set so as not to overlap with slots corresponding to other SSB indices.

[0128]

[0129] In the NR system, PDSCH can be mapped to the time domain according to PDSCH mapping type A or B. PDSCH mapping types A and B can be defined as shown in Table 1 below.

[0130]

[0131]

[0132] Type A (i.e., PDSCH mapping type A) may be slot-based transmission. When Type A is used, the position of the start symbol of the PDSCH may be set to one of {0, 1, 2, 3}. When Type A and a normal CP are used, the number of symbols constituting the PDSCH (e.g., the duration of the PDSCH) may be set to one of 3 to 14 within a symbol boundary. Type B (i.e., PDSCH mapping type B) may be non-slot-based transmission. When Type B is used, the position of the start symbol of the PDSCH may be set to one of 0 to 12. When Type B and a normal CP are used, the number of symbols constituting the PDSCH (e.g., the duration of the PDSCH) may be set to one of {2, 4, 7} within a symbol boundary. A DMRS (hereinafter referred to as "PDSCH DMRS") for demodulating a PDSCH (e.g., data) may be determined based on an ID indicating a PDSCH mapping type (e.g., Type A, Type B) and a length. The ID may be defined differently depending on the PDSCH mapping type.

[0133]

[0134] As the NR phase 1 standardization is finalized in Rel-15 and phase 2 standardization begins in Rel-16, new features are being discussed in the NR system. One of the most representative features is NR-U (Unlicensed). NR-U is a technology that supports operation in unlicensed spectrum used for purposes such as Wi-Fi in order to increase network capacity by increasing the utilization of limited frequency resources. It was standardized as LTE-LAA (Licensed-Assisted Access) technology in Rel-13 and has continued to evolve through LTE-eLAA (Enhanced LAA) in Rel-14 and LTE-FeLAA (Futher Enhanced LAA) in Rel-15. Following the SI for NR-U, standardization work is also underway through WI in Rel-16.

[0135] In the NR-U system, the terminal can determine whether a signal is transmitted from the base station based on the DRS (Discovery Reference Signal) received from the base station, just like in the general NR system. In the NR-U system in SA (Stand-Alone) mode, the terminal can obtain synchronization and / or system information based on the DRS. In the NR-U system, the DRS can be transmitted according to the regulations of the unlicensed band (e.g., transmission band, transmission power, transmission time, etc.). For example, according to the Occupied Channel Bandwidth (OCB) regulations, the signal can be configured and / or transmitted so as to occupy 80% of the total channel bandwidth (e.g., 20 MHz).

[0136] In an NR-U system, a communication node (e.g., a base station, a terminal) may perform LBT (Listen Before Talk) before transmitting a signal and / or channel for coexistence with other systems. The signal may be a synchronization signal, a reference signal (e.g., DRS, DMRS, CSI (channel state information)-RS, PT (phase tracking)-RS, SRS (sounding reference signal)), etc. The channel may be a downlink channel, an uplink channel, a sidelink channel, etc. In embodiments, the signal may mean "signal," "channel," or "signal and channel." LBT may be an operation to check whether a signal is transmitted by another communication node. If it is determined by LBT that there is no transmission signal (e.g., if LBT is successful), the communication node may transmit a signal in an unlicensed band. If it is determined by LBT that there is a transmission signal (e.g., if LBT fails), the communication node may not transmit a signal in the unlicensed band. Communication nodes can perform LBT according to various categories before transmitting a signal. The LBT category may vary depending on the type of transmitted signal.

[0137]

[0138] Meanwhile, NR V2X (vehicular-to-everything) communication technology is being discussed at the NR standardization meeting. NR V2X communication technology, based on device-to-device (D2D) communication technology, can support communication between vehicles, between vehicles and infrastructure, and between vehicles and pedestrians. Technologies to reduce power consumption and improve reliability for NR V2X communication are also being discussed.

[0139] NR V2X communication (e.g., sidelink communication) can be performed according to three transmission methods (e.g., unicast, broadcast, and groupcast). When the unicast method is used, a PC5-RRC connection can be established between a first terminal (e.g., a transmitting terminal that transmits data) and a second terminal (e.g., a receiving terminal that receives data), and the PC5-RRC connection can mean a logical connection for a pair between a source ID of the first terminal and a destination ID of the second terminal. The first terminal can transmit data (e.g., sidelink data) to the second terminal. When the broadcast method is used, the first terminal can transmit data to all terminals. When the groupcast method is used, the first terminal can transmit data to a group consisting of multiple terminals (e.g., a groupcast group). In SL communication (e.g., SL-U communication), a transmitting terminal may mean a terminal that transmits data, and a receiving terminal may mean a terminal that receives data.

[0140] When a unicast method is used, the second terminal can transmit feedback information (e.g., ACK (acknowledgement) or NACK (negative ACK)) regarding data received from the first terminal to the first terminal. In the embodiments below, the feedback information may be referred to as "HARQ-ACK", "feedback signal", "PSFCH (physical sidelink feedback channel) signal", etc. If an ACK is received from the second terminal, the first terminal can determine that the data has been successfully received by the second terminal. If a NACK is received from the second terminal, the first terminal can determine that the second terminal has failed to receive the data. In this case, the first terminal can transmit additional information to the second terminal based on a hybrid automatic repeat request (HARQ) method. Alternatively, the first terminal can improve the probability of data reception by the second terminal by retransmitting the same data to the second terminal.

[0141] For sidelink communication, transmission of a data channel for data transmission and a control channel containing scheduling information for data resource allocation may be required. In sidelink communication, the data channel may be a Physical Sidelink Shared Channel (PSSCH), and the control channel may be a Physical Sidelink Control Channel (PSCCH). The data and control channels may be multiplexed in resource domains (e.g., time and frequency resource domains).

[0142] FIG. 12 is a conceptual diagram illustrating embodiments of a method for multiplexing a control channel and a data channel in sidelink communication.

[0143] Referring to FIG. 12, sidelink communication can support Option 1A, Option 1B, Option 2, and Option 3. If Option 1A and / or Option 1B are supported, control channels and data channels can be multiplexed in the time domain. If Option 2 is supported, control channels and data channels can be multiplexed in the frequency domain. If Option 3 is supported, control channels and data channels can be multiplexed in the time and frequency domains. Sidelink communication can natively support Option 3.

[0144] In sidelink communications (e.g., NR-V2X sidelink communications), a basic unit of resource configuration may be a subchannel. A subchannel may be defined by time and frequency resources. For example, a subchannel may be composed of multiple symbols (e.g., OFDM symbols) in the time domain and multiple resource blocks (RBs) in the frequency domain. A subchannel may be referred to as an RB set. Within a subchannel, data channels and control channels may be multiplexed based on Option 3.

[0145] In sidelink communication (e.g., NR-V2X sidelink communication), transmission resources can be allocated based on Mode 1 or Mode 2. When Mode 1 is used, a base station can allocate sidelink resources for data transmission to a transmitting terminal within a resource pool, and the transmitting terminal can transmit data to a receiving terminal using the sidelink resources allocated by the base station. Here, the transmitting terminal may be a terminal that transmits data in sidelink communication, and the receiving terminal may be a terminal that receives data in sidelink communication.

[0146] When Mode 2 is used, a transmitting terminal can autonomously select sidelink resources to be used for data transmission by performing a resource sensing operation (e.g., a resource sensing procedure) and / or a resource selection operation (e.g., a resource selection procedure) within a resource pool. The base station can configure a resource pool for Mode 1 and a resource pool for Mode 2 to the terminal(s). The resource pool for Mode 1 can be configured independently from the resource pool for Mode 2. Alternatively, a common resource pool can be configured for Mode 1 and Mode 2.

[0147] When Mode 1 is used, the base station can schedule resources used for sidelink data transmission to a transmitting terminal, and the transmitting terminal can transmit sidelink data to a receiving terminal using the resources scheduled by the base station. Therefore, resource collisions between terminals can be prevented. When Mode 2 is used, the transmitting terminal can select any resource by performing a resource sensing operation and / or a resource selection operation, and can transmit sidelink data using any selected resource. Since the above-described procedure is performed based on the individual resource sensing operation and / or resource selection operation of each transmitting terminal, collisions between the selected resources may occur.

[0148]

[0149] A terminal with reduced capability (hereinafter referred to as a "RedCap terminal") can operate in a specific usage environment. The capability of a RedCap terminal may be lower than that of a new radio (NR) normal terminal, and may be higher than the capabilities of each of an LTE-MTC (machine type communication) terminal, an NB (narrow band)-IoT (internet of things) terminal, and an LPWA (Low Power Wide Area) terminal. The basic capabilities of a RedCap terminal and the technology to support them were introduced in NR Rel-17. For example, there may be terminals that require "high data rate and low latency conditions" (e.g., surveillance cameras) and / or terminals that require "low data rate, high latency conditions, and high reliability" (e.g., wearable devices). To support the above-mentioned terminals, the maximum carrier bandwidth in FR1 may be reduced from 100 MHz to 20 MHz, and in FR2, the maximum carrier bandwidth may be reduced from 400 MHz to 100 MHz. The number of receive antennas in a RedCap terminal may be smaller than that of a typical NR terminal. When the carrier bandwidth and number of receive antennas are reduced, the reception performance of the RedCap terminal may be reduced, and thus the coverage of the RedCap terminal may be reduced. Therefore, new technologies that take this into account have been introduced.

[0150] Additionally, NR Rel-17 discussed extending the existing 52.6 GHz frequency band to support NR system operation in higher frequency bands than 52.6 GHz. As the frequency band in which a communication system operates increases, frequency offset error and phase noise may increase. For robust operation in such environments, the use of large SCS may be necessary. In the FR2 band, 60 kHz SCS and / or 120 kHz SCS may be supported, and additionally, 480 kHz SCS and / or 960 kHz SCS may be supported. In addition, "physical layer signal and channel design" and "physical layer procedures" according to the new SCS may be required. Regarding the initial access procedure, 120 kHz SSB and / or 240 kHz SSB may be supported in the FR2 band, and additionally, 480 kHz SSB and / or 960 kHz SSB may be supported. Here, 120kHz SSB may refer to SSB transmitted on a radio resource to which 120kHz SCS is applied, and 240kHz SSB may refer to SSB transmitted on a radio resource to which 240kHz SCS is applied. Therefore, to support the new SCS, new features such as an "initial BWP setup method" and an "SSB burst aggregation pattern" have been introduced.

[0151]

[0152] Bidirectional communication (duplex) between communication nodes (e.g., base stations and terminals) can be performed based on a half-duplex or full-duplex method. According to the half-duplex method, a communication node can perform only one of the operations of transmitting a signal and receiving a signal at a time. In other words, a communication node may not perform the transmission and reception operations simultaneously. According to the full-duplex method, a communication node can perform the transmission and reception operations simultaneously or at different times. Full-duplex communication can be easily performed in a frequency division duplex (FDD) system (e.g., a system using an FDD carrier, a paired spectrum, etc.). A communication node can perform the transmission and reception operations in separate frequency domains (e.g., an uplink carrier and a downlink carrier). Therefore, interference between signals in the separate frequency domains can be very small. On the other hand, in TDD systems (e.g., systems using TDD carriers, unpaired spectrum, etc.), communication nodes may perform transmission and reception operations within a common frequency domain (e.g., a carrier commonly used for uplink and downlink transmission), and when transmission and reception operations are performed simultaneously, the transmission signal may interfere with the reception signal. Therefore, a self-interference cancellation technology may be required to perform full-duplex communication in a TDD system. Full-duplex communication in a TDD system may be referred to as in-band full-duplex communication. On the other hand, half-duplex communication can be easily performed in both FDD and TDD systems because it does not have the aforementioned interference problem.

[0153] Figure 13 is a conceptual diagram for explaining full-duplex communication in the same band.

[0154] Referring to FIG. 13, a base station (1301) can perform bidirectional communication with terminals (1302, 1303) based on a full-duplex method. That is, the base station (1301) can perform a transmission operation and a reception operation at the same time. On the other hand, the terminals (1302, 1303) can perform only one of the transmission operation and the reception operation at a time. For example, the base station (1301) can transmit a downlink signal to a first terminal (1302) at time t1, and simultaneously receive an uplink signal from a second terminal (1303) at time t1. The downlink signal and the uplink signal can be transmitted in the same band (e.g., within the same carrier). In this case, the downlink signal can act as self-interference to the uplink signal reception of the base station. The base station can improve the reception performance of the uplink signal by removing or alleviating the self-interference in advance before detecting the uplink signal from the received signal.

[0155] In addition, the uplink signal transmitted by the second terminal (1303) may interfere with the downlink signal reception of the first terminal (1302). Interference between uplink signals and downlink signals (e.g., uplink signals and downlink signals transmitted and received from different nodes (i.e., the first terminal and the second terminal)) may be referred to as cross-link interference. When the distance between the first terminal (1302) and the second terminal (1303) is close, or when the reception beam direction of the first terminal (1302) is similar to the transmission beam direction of the second terminal (1303), the strength of the cross-link interference that the uplink signal has on the downlink transmission may be large. Therefore, the downlink signal reception performance of the first terminal (1302) may deteriorate. In particular, when the first terminal (1302) does not have the ability to remove the cross-link interference, the performance deterioration may be more severe.

[0156] To address the above-described cross-link interference problem between terminals, in the same band full-duplex communication, uplink and downlink signals may be transmitted in different resource domains (e.g., time-frequency resource domains). For example, uplink and downlink signals transmitted in the same band (e.g., the same carrier) may be transmitted in different time resource domains. Alternatively, uplink and downlink signals transmitted in the same band (e.g., the same carrier) may be transmitted simultaneously (e.g., at the same time), and in this case, the uplink and downlink signals may be transmitted in different frequency domains.

[0157] FIG. 14 is a conceptual diagram illustrating an embodiment for explaining a method for multiplexing uplink signals and downlink signals in full-duplex communication.

[0158] Referring to FIG. 14, uplink signals and downlink signals within one serving cell (or carrier) may be multiplexed and transmitted using different resources (e.g., different time-frequency resources). For example, a first downlink signal (1401), a second downlink signal (1402) (or a first uplink signal (1403)), and a second uplink signal (1404) may be transmitted using different time resources (i.e., time division multiplexing (TDM) may be performed). As another example, the first uplink signal (1403) and the second downlink signal (1402) may be transmitted in the same time resource and different frequency resources (i.e., frequency division multiplexing (FDM) may be performed).

[0159] The base station can receive the above uplink signals and transmit downlink signals. For example, the base station can transmit the second downlink signal to a terminal (e.g., a first terminal) and simultaneously receive the first uplink signal from another terminal (e.g., a second terminal). At this time, the second downlink signal can act as self-interference (or cross-link interference) on the base station's reception of the first uplink signal. In addition, the first uplink signal can act as cross-link interference on the first terminal's reception of the second downlink signal. However, according to the present embodiment, the frequency domain in which the first uplink signal is transmitted and the frequency domain in which the second downlink signal is transmitted can be separated from each other, and when the frequency domains are sufficiently far apart, the above-described cross-link interference can be alleviated. Here, the first terminal and the second terminal can be the first terminal (1402) and the second terminal (1403) as exemplified in FIG. 13, respectively.

[0160] In the embodiment of FIG. 14, the time period in which simultaneous transmission of uplink signals and downlink signals is allowed as described above may be referred to as a sub-band full-duplex (SBFD) period hereinafter.

[0161] In Rel-18, the beginning of 5G-Advanced, research is being conducted on full-duplex communication methods to increase spectral efficiency, enhance uplink performance, and reduce latency. More specifically, base stations can perform both transmission and reception operations simultaneously, while terminals can perform only one of the two operations at a time. Research is also underway on sub-band full-duplex (SBFD) communication methods, in which frequency resources for uplink and downlink resources are separated during the time period when simultaneous transmission of uplink and downlink signals between terminals and base stations is permitted.

[0162]

[0163] In 3GPP Rel-16, when long C-DRX (connected-DRX (discontinuous reception)) is configured for a UE, the UE can be configured to monitor PDCCH (e.g., DCI format 2_6) before the start of the DRX on-duration cycle. If the PDCCH monitored by the UE indicates wake-up (=1), the UE wakes up, switches to the active state, and performs an operation (e.g., PDCCH monitoring). On the other hand, if the PDCCH monitored by the UE indicates sleep (=0), the UE can maintain the sleep state to reduce power consumption. This power saving technique was introduced by using DCI including a CRC (cyclic redundancy check) scrambled by PS-RNTI, and is called DCP (DCI with CRC scrambled by PS-RNTI).

[0164] In addition, in 3GPP Rel-18, research was conducted on a technology to switch a terminal from a sleep state to an active state by detecting a low-power wake-up signal (LP-WUS) using a low-power wake-up receiver (LP-WUR) instead of PDCCH monitoring. A terminal switched to an active state through LP-WUS detection can perform PDCCH monitoring and / or data transmission and reception. While the LP-WUR performs monitoring operations for LP-WUS detection, the main receiver (MR) of the terminal can remain in a sleep state. Accordingly, the power consumption of the terminal can be further reduced compared to the DCP power saving technique of the existing Rel-16.

[0165] Based on the research described above, 3GPP Rel-19 is working on technical specifications related to LP-WUS design. This work may include standardization of operation in RRC IDLE mode, RRC INACTIVE mode, and RRC CONNECTED mode. This disclosure primarily proposes methods and procedures related to RRC CONNECTED mode operation of LP-WUS in Rel-19.

[0166] The operating modes of LP-WUR for LP-WUS monitoring can be broadly divided into two. The first is the duty-cycled WUR mode, in which LP-WUR periodically becomes active and performs LP-WUS monitoring. The second is the continuous WUR mode, in which LP-WUR always remains active and performs LP-WUS monitoring.

[0167] In general, duty-cycle WUR mode can offer greater power savings than continuous WUR mode, which performs monitoring at all times, because it only monitors at set times. However, duty-cycle WUR mode requires continuous recognition and maintenance of slot and / or radio frame numbers to ensure monitoring is performed only at set times. This can potentially increase latency compared to continuous WUR mode.

[0168] The detailed description of the present disclosure described below is primarily based on the duty-cycle WUR mode. However, various embodiments of the present disclosure can be equally applied to the continuous WUR mode.

[0169]

[0170] Option 1

[0171] In RRC CONNECTED mode, LP-WUS can support various operations and can basically replace the C-DRX operation linked to Rel-16 DCP operation (Option 1 in the description below). Wake-up / sleep indication, which was performed through PDCCH monitoring in Rel-16 DCP method, can be performed using LP-WUS.

[0172] More specifically, a terminal configured with C-DRX can perform LP-WUS monitoring using LP-WUR before the start of the C-DRX on-duration cycle. At this time, if LP-WUS is detected, the terminal can wake up, switch to an active state, and operate in normal mode. On the other hand, if LP-WUS is not detected, the terminal can continue to maintain a sleep state during the C-DRX on-duration cycle to reduce power consumption.

[0173] FIG. 15 is a conceptual diagram illustrating Option 1, in which LP-WUS replaces Rel-16 DCP in duty-cycle mode according to one embodiment of the present invention.

[0174] Referring to FIG. 15, the LP-WUR of the terminal can perform LP-WUS monitoring in an LP-WUS occasion (1501) where the LP-WUS can be transmitted. If LP-WUS is detected (1511), the terminal can wake up, switch to the active state of C-DRX, and perform an operation (1512). On the other hand, if LP-WUS is not detected, the terminal can maintain a sleep state to reduce power consumption.

[0175] In this case, the terminal can perform monitoring for LP-WUS ocasion(s) from the time point at which a specific offset is applied from the start time point (1502) of the C-DRX on-duration. The LP-WUS ocasion(s) can be set as a time interval requiring monitoring or can be preset as the number thereof. Alternatively, the LP-WUS ocasion(s) can be set via separate parameters. For example, it is also possible to set via the periodicity and time interval or number (e.g., the number of LP-WUS monitoring) of the LP-WUS ocasion(s), and at this time, it is desirable to consider the C-DRX setting period, etc. More specifically, it is desirable that the period of the LP-WUS ocasion(s) be set to be the same as the C-DRX period or to be set to a multiple of the C-DRX period.

[0176] Specifically, if the cycle of the LP-WUS ordering is set to be the same as the C-DRX cycle, separate signaling for the cycle of the LP-WUS ordering may not be required. On the other hand, if the LP-WUS cycle is set to a multiple of the C-DRX cycle, the operation indicated through the LP-WUS can be applied equally to all C-DRX sections within the LP-WUS cycle. For example, if the LP-WUS cycle is set to M times the C-DRX cycle (where M is a natural number greater than or equal to 2), the UE can perform an operation according to the same LP-WUS instruction in M ​​C-DRX sections included in the LP-WUS cycle.

[0177] When LP-WUS indicates wake-up, the terminal may wake up and perform PDCCH monitoring in M ​​C-DRX intervals. On the other hand, when LP-WUS indicates 'sleep-on' or LP-WUS is not detected, the terminal may not perform PDCCH monitoring in M ​​C-DRX intervals.

[0178] The LP-WUR of a terminal can monitor LP-WUS occasions corresponding to a given time or number. The last monitored LP-WUS occasion can be the last monitorable LP-WUS occasion, considering the time required for the terminal to transition to an active state (the time gap in FIG. 15).

[0179] Alternatively, a specific LP-WUS monitoring operation can be configured for each terminal group. The LP-WUS sequence transmitted in the specific LP-WUS monitoring operation can be expressed as a bitmap, and the bitmap can indicate whether each terminal in the group should wake up. A specific terminal can determine whether to wake up based on a bit at a specific position in the bitmap. In this case, the position of the bit corresponding to a specific terminal in the bitmap can be preset and included in the LP-WUS configuration information.

[0180] The time required for a terminal to transition to an active state (wake-up delay) can vary depending on several factors. For example, wake-up delay includes LP-WUS processing time, transition time for MR ramp-up, and MR time and frequency synchronization time, and may vary depending on the terminal's capabilities. A terminal can report its wake-up delay through the capability reporting process, and the wake-up delay may vary depending on the subcarrier spacing of the signal.

[0181] Additionally, the time required for a terminal to transition from various sleep states (e.g., ultra-deep sleep mode, deep sleep mode, light sleep mode, micro sleep mode) to an active state may vary depending on the terminal's state. The terminal can report the time required to transition to an active state to the base station through a capability report. The base station can set an appropriate offset and time gap based on the values ​​reported by the terminal.

[0182] After the terminal reports multiple time values ​​required to transition to the active state, the terminal can select a sleep state to maintain while performing LP-WUS monitoring by considering the configured offset and time interval. For example, it can be assumed that the terminal reports the time required to transition from the micro sleep state to the active state as A ms and the time required to transition from the light sleep state to the active state as B ms (B>A). In this case, if the base station sets the time interval as X ms (A < X < B), the terminal can select the micro sleep state instead of the light sleep state as a sleep state to maintain during LP-WUS monitoring.

[0183] Even among terminals, the time required to transition to an active state may vary. The base station can receive capability reports from multiple terminals regarding the time required to transition to an active state and, taking this into account, can set offsets and time intervals that can support multiple terminals simultaneously. For example, the base station can set the offset and time interval based on the largest time required to transition to an active state reported by multiple terminals. Meanwhile, if the time required to transition to an active state differs significantly among terminals, the base station can group terminals that require similar transition times, taking this time difference into account, and set the offset and time interval for each terminal group based on the largest transition time within the group.

[0184] After reporting information about the time required to transition from a sleep state to an active state (i.e., wake-up delay) to the base station through a capability report, the terminal can additionally transmit UE assistant information (UAI) to the base station. The UAI may include additional information that the base station can consider when setting offsets and time intervals based on the wake-up delay reported through the capability report. For example, if a terminal reports a specific wake-up delay value through a capability report, but the terminal is actually capable of supporting a shorter wake-up delay, the terminal can inform the base station of this value through the UAI. In this case, the base station can set the offset and time interval based on the shorter wake-up delay than the wake-up delay reported through the capability report based on the UAI received from the terminal.

[0185] The assistance information included in the UAI may be provided in the form of an index indicating at least one of a plurality of wake-up delay values ​​or an index indicating a capability level. In this case, the size of the index may indicate the wake-up delay or the capability level, and a small index value may indicate a small wake-up delay or a high capability level, or conversely, a small index value may indicate a large wake-up delay or a low capability level. Alternatively, the terminal may transmit an actually supportable wake-up delay value through the UAI instead of an index. This wake-up delay value may be configured in units of symbols, slots, subframes, or radio frames, or may also be expressed as an absolute time value in units of milliseconds.

[0186] The above-described LP-WUS monitoring ocasion settings, time interval settings according to terminal capability reports, and terminal sleep mode determination, etc. are not limited to the operation of Option 1, and can be applied to all options and embodiments of the present disclosure.

[0187] In the operation of Option 1, if the LP-WUS can indicate two states, wake-up and sleep, similar to the Rel-16 DCP, when an LP-WUS indicating wake-up is detected, the terminal can wake up and transition to the active state, and when an LP-WUS indicating sleep is detected, the terminal can remain in the sleep state. Alternatively, the LP-WUS may indicate only one state, either wake-up or sleep. In this case, the state indicated by the LP-WUS can be preset through system information or RRC signaling per terminal. In this way, the state(s) indicated by the sequence of the LP-WUS are not only applied to the operation of Option 1, but can be equally applied to the operations of all options to which the LP-WUS is applied.

[0188] Separate configuration may be required for cases where LP-WUS is not detected. More specifically, if LP-WUS is not detected, the terminal may be configured to transition from C-DRX On-Duration to Active state. Alternatively, the terminal may be configured in advance to remain in Sleep state even if LP-WUS is not detected.

[0189] Alternatively, the terminal can be configured to transition from C-DRX on-duration to the active state even if LP-WUS is not detected. In this case, the terminal can transition to the active state not only when LP-WUS is detected and instructs wake-up, but also when LP-WUS is not detected. Conversely, the terminal can be configured to remain in a sleep state in C-DRX on-duration even if LP-WUS is not detected. If this behavior is not configured in advance, the terminal can always transition from C-DRX on-duration to the active state by default.

[0190] If an entry condition for performing LP-WUS monitoring operation is preset, the terminal may maintain a sleep state in C-DRX on-duration and not perform PDCCH monitoring if LP-WUS is not detected while performing LP-WUS monitoring by satisfying the condition. On the other hand, if an exit condition is satisfied while performing LP-WUS monitoring, the terminal may always switch to an active state in C-DRX on-duration and perform PDCCH monitoring. Additionally, if Rel-16 DCP operation is configured, the terminal may perform a wake-up operation according to the Rel-16 DCP configuration.

[0191] In addition, when periodic RSRP (reference signal received power) reporting and / or periodic CSI (channel state information) reporting are configured to overlap with DRX on-duration, additional parameter settings may be required to consider when to maintain sleep state in DRX on-duration depending on LP-WUS detection and signaling. For example, even when the UE maintains sleep state in DRX on-duration depending on LP-WUS detection and signaling, the UE may be configured to perform periodic RSRP reporting and / or CSI reporting. On the other hand, when these parameters are not configured, the UE may not perform periodic RSRP reporting and / or CSI reporting while maintaining sleep state in DRX on-duration. The above-described parameters may be configured individually for each report type, or may be configured to be configured as a single parameter and applied equally to all reports.

[0192] Additionally, in addition to parameters for LP-WUS operation (e.g., period, offset, monitoring occasion, time interval, etc.), information regarding the time and frequency resources on which LP-WUS operates can be preset. This information can be transmitted to the terminal via system information or terminal-specific RRC signaling.

[0193] The parameters and configuration information for the above-described LP-WUS and LP-WUS ocasion(s) can be received from the base station via the MR module of the terminal, and the reception of such parameters and configuration information can be performed in the same manner for other Options (Option 2, Option 3, Option 4) to be described below.

[0194]

[0195] Option 2

[0196] In another operation mode, LP-WUS ocasion(s) may be set outside of C-DRX on-duration. In this case, transition to active state of the terminal may be instructed even in a time interval other than C-DRX on-duration, and LP-WUS ocasion(s) may be set regardless of C-DRX on-duration to instruct transition to active state of the terminal in a specific time interval regardless of C-DRX on-duration, and in this case, PDCCH monitoring according to existing C-DRX on-duration may not be performed while performing LP-WUS monitoring ('Option 2' in the description below).

[0197] More specifically, the terminal may follow the existing C-DRX operation during the C-DRX on-duration, or follow the Rel-16 DCP method or the method of Option 1 described above. Additionally, the terminal may monitor LP-WUS outside the on-duration, and if LP-WUS is detected, the terminal may switch to the active state and monitor the PDCCH even outside the on-duration.

[0198] In addition to the method of Option 1, the LP-WUS occasion(s) for performing PDCCH monitoring by transitioning to an active state outside of on-duration may be commonly configured with the same parameter(s) as the duty-cycle and related configuration values ​​(e.g., time location, periodicity, time duration, offset, etc.) for the LP-WUS occasion(s) of Option 1 and may apply the same LP-WUS sequence. Alternatively, the LP-WUS occasion(s) for performing PDCCH monitoring by transitioning to an active state outside of on-duration may be separately configured with different parameter(s) from the LP-WUS occasion(s) of Option 1 and may apply the same LP-WUS sequence or different LP-WUS sequences.

[0199] At this time, the terminal transitioned to the active state can perform PDCCH monitoring and perform data transmission and reception operations according to the scheduling information provided on the PDCCH. The terminal transitioned to the active state by LP-WUS can return to the sleep state after a certain period of time to reduce power consumption. Conditions for the terminal to return from the active state to the sleep state can be separately set.

[0200] As one of the conditions for a terminal to transition from an active state to a sleep state, the terminal may start a timer when transitioning to the active state. When the timer expires after a set period of time, the terminal may transition from the active state to the sleep state. If the terminal receives an additional PDCCH before the timer expires, the terminal may perform an operation according to the scheduling information of the corresponding PDCCH. In this case, the timer may be extended. The timer may be extended until the operation according to the PDCCH scheduling information is completed, or may be extended according to a specific time interval set in advance.

[0201] The above-described timer may be the same as the timer used in the existing C-DRX operation. Additionally, it may be a timer set separately for the LP-WUS operation. As another condition, a terminal that has been switched to the active state by LP-WUS may maintain the state and switch back to the sleep state through additional signaling. At this time, the additional signaling indicating the switch to the sleep state may be an LP-WUS sleep indicator that is distinct from the LP-WUS wake-up indicator. Alternatively, DCI-based PDCCH skipping introduced in Rel-17 to save power of the terminal may be applied. A similar PDCCH-based indication may also be used.

[0202] More specifically, PDCCH skipping can be indicated through a PDCCH monitoring adaptation field of DCI transmitted via PDCCH. If the corresponding DCI field is set to 1 bit, the field set to '0' may indicate that PDCCH skipping is not applied, and the field set to '1' may indicate that PDCCH monitoring is not to be performed during a time interval (e.g., the number of slots per subcarrier interval) previously set through RRC signaling, etc. If the corresponding DCI field is set to 2 bits, the field set to '00' may indicate that PDCCH skipping is not to be applied, and the field set to '01' may indicate that PDCCH monitoring is not to be performed during a time interval corresponding to the first value among the set time interval values. The field set to '10' may indicate that PDCCH monitoring may not be performed during a time interval corresponding to the second value among the set time interval values. A field set to '11' may indicate that PDCCH monitoring will not be performed during the time interval corresponding to the third value among the configured time interval values. If the preset time interval values ​​are limited to two, '11' may not be used and may be used as a reserved value.

[0203] When LP-WUS operation and PDCCH skipping operation are performed in conjunction, the base station can set the PDCCH monitoring adaptation field of DCI to 2 bits. At this time, the values ​​of the time intervals set in advance so that PDCCH monitoring is not performed can be set to a maximum of 2. The unused and reserved value '11' can be utilized as a value to indicate transition to sleep state after performing LP-WUS monitoring in wake-up state.

[0204] Alternatively, the existing PDCCH skipping operation may be applied as is. For example, the terminal may not perform PDCCH monitoring during the designated time interval according to the existing PDCCH skipping operation. Instead, the terminal may perform LP-WUS monitoring during the designated time interval. In this case, if LP-WUS is detected during the LP-WUS monitoring process, the terminal may suspend PDCCH skipping even within the designated time interval. Thereafter, the terminal may transition to the active state and resume PDCCH monitoring.

[0205] When the terminal detects LP-WUS in LP-WUS occasion(s) set outside of the C-DRX on-duration and switches to the active state, PDCCH monitoring may be performed by a pre-set timer. In this case, if the on-duration time period set by the timer overlaps with the existing C-DRX on-duration time period, the terminal may stop the corresponding PDCCH monitoring operation and perform the operation according to the existing C-DRX setting. When the above-described Option 1 or Rel-16 DCP operation is set, the operation in the C-DRX may be performed according to the corresponding operation method.

[0206] Alternatively, if LP-WUS occasion(s) are configured outside of the C-DRX on-duration (i.e., if Option 2 operation mode is configured), the UE may not transition to the Active state from the existing C-DRX on-duration. In this case, the UE transitioned to the Active state by LP-WUS detection performs PDCCH monitoring according to a preset timer, and may continue to perform PDCCH monitoring even if the time period configured by the timer overlaps with the existing C-DRX on-duration.

[0207] When it overlaps with the C-DRX on-duration time period, the PDCCH monitoring operation to be performed by the UE can be configured in advance through system information provided to the UE or UE-specific RRC signaling. In addition, it can also be implicitly determined depending on whether other Options are configured in addition to the Option 2 operation. For example, when other Options are additionally configured in addition to the Option 2 operation, in order to prevent conflicts with the Options, PDCCH monitoring can be stopped regardless of whether the timer has completed when it overlaps with the C-DRX on-duration time period.

[0208] Figures 16a to 16c are conceptual diagrams for explaining Option 2 according to one embodiment of the present invention.

[0209] Referring to FIGS. 16A to 16C, the terminal may monitor LP-WUS ocasion(s) outside of the C-DRX on-duration. If LP-WUS is detected, the terminal may transition to the active state. After a certain period of time has elapsed according to a timer that starts after transitioning to the active state, the terminal may transition back to the sleep state.

[0210] FIG. 16a illustrates a case where LP-WUS ocasion(s) are set to be constant regardless of whether C-DRX is set or regardless of C-DRX on-duration, FIG. 16b illustrates a case where LP-WUS ocasion(s) are set only outside C-DRX on-duration, and FIG. 16c illustrates a case where, in addition to the LP-WUS ocasion(s) for Option 1, separate LP-WUS ocasion(s) are set for wake-up of a terminal outside C-DRX on-duration.

[0211] Referring to FIG. 16a, even if the LP-WUS occasion(s) are set to a constant regardless of whether C-DRX is present, the terminal can perform LP-WUS monitoring only outside of the C-DRX on-duration. That is, LP-WUS monitoring may not be performed during the time period overlapping with the C-DRX on-duration. In the Option 2 operation, when the terminal performs PDCCH monitoring after waking up by LP-WUS and switching to the active state, if the corresponding PDCCH monitoring time overlaps with the C-DRX on-duration, the terminal may stop PDCCH monitoring.

[0212] When Option 1 and Option 2 are set together, the terminal can perform PDCCH monitoring even after being woken up by LP-WUS of Option 2 and switched to the active state. However, the existing PDCCH monitoring operation may be stopped at an appropriate time for LP-WUS monitoring according to Option 1. Alternatively, the terminal may perform LP-WUS monitoring regardless of C-DRX on-duration. Even if the time period for performing PDCCH monitoring according to the timer after switching to the active state by LP-WUS overlaps with the C-DRX on-duration, the terminal can continuously perform PDCCH monitoring without stopping.

[0213] In the embodiments of FIGS. 16A to 16C, a terminal that has transitioned to an active state may transition to a sleep state by a timer. However, as described above, the terminal may also transition to a sleep state by conditions other than the timer. In the above embodiments, on-duration may refer to the active time during which PDCCH monitoring is performed. On the other hand, outside of on-duration may refer to a time outside of the active time.

[0214] Referring to FIG. 16c, the duty cycles and related configuration values ​​(e.g., time location, periodicity, time duration, offset, etc.) for the LP-WUS occasion(s) according to Option 1 (i.e., LP-WUS occasion(s) for DRX wake-up) and the LP-WUS occasion(s) applied to Option 2 (i.e., additional LP-WUS occasion(s) for wake-up outside of DRX on-duration) can be set through the same parameters. In this case, the same LP-WUS sequence can be applied. In addition, the same LP-WUS sequence can be applied by setting different parameters to have different values, or different LP-WUS sequences can be applied. More specifically, when Option 2 is additionally set to Option 1, the period of Option 2 can be set to be the same as the period of Option 1 without separate configuration. Option When applying the same cycle as the cycle of 1, the starting point of the LP-WUS occasion for LP-WUS monitoring of each cycle can be set as an offset (offset in Fig. 16c) with respect to the end point of the C-DRX on-duration.

[0215] When multiple LP-WUS occasions are set, the starting point of the LP-WUS occasion can be set as a combination of a separate periodicity (periodicity in Fig. 16c) and the number of LP-WUS occasions or the end point of LP-WUS monitoring. That is, the setting can be a combination of {starting point, separate period, number} or {starting point, separate period, end point}. When Option 2 is set separately from Option 1, the LP-WUS period for Option 2 and the offset indicating the start point of PDCCH monitoring from the period can be set separately.

[0216]

[0217] Option 3

[0218] Unlike Option 2 above, LP-WUS ocasion(s) may be set within the C-DRX on-duration. In this case, the terminal may be instructed to transition to the active state within the C-DRX on-duration ('Option 3' in the description below).

[0219] More specifically, the terminal may remain in a sleep state even during C-DRX on-duration. However, if the terminal detects an LP-WUS while monitoring LP-WUS occasion(s), it may transition to an active state. The terminal that has transitioned to an active state may transition back to a sleep state under various conditions, similar to the method described above in Option 2.

[0220] Figure 17 is a conceptual diagram for explaining Option 3 according to one embodiment of the present invention.

[0221] Referring to FIG. 17, LP-WUS occasion(s) can be set within the C-DRX on-duration. In this case, the terminal can maintain a sleep state even during the C-DRX on-duration and monitor LP-WUS. When LP-WUS is detected, the terminal can be switched to an active state. The embodiment of FIG. 17 shows an example in which a terminal switched to an active state is switched to a sleep state by a timer. However, as described above, the terminal can also be switched to a sleep state by conditions other than a timer.

[0222] In Option 3 operation mode, C-DRX on-duration may refer to the time for which the drx-onDuration timer is set. In this case, the existing terminal must perform PDCCH monitoring operation. However, a terminal configured in Option 3 operation mode may not perform PDCCH monitoring and instead monitor LP-WUS. Only when LP-WUS is detected, the terminal may switch to the active state and perform PDCCH monitoring (hereinafter referred to as 'Option 3-A').

[0223] Alternatively, in Option 3 operation mode, C-DRX on-duration may mean on-duration according to the C-DRX configuration, but the drx-onDuration timer is not set. In this case, the terminal does not perform PDCCH monitoring as before. However, it can monitor LP-WUS, and can switch to the active state and perform PDCCH monitoring only when LP-WUS is detected (hereinafter referred to as 'Option 3-B').

[0224] A terminal that switches to an active state upon LP-WUS detection performs PDCCH monitoring according to a preset timer. At this time, if the C-DRX on-duration is exceeded, the terminal may stop PDCCH monitoring. Alternatively, even if the C-DRX on-duration is exceeded, the terminal may continue to perform PDCCH monitoring according to the timer. When the C-DRX on-duration is exceeded, which PDCCH monitoring operation the terminal will perform can be configured in advance through system information or UE-specific RRC signaling. In addition, it may be implicitly determined depending on whether other Options are configured in addition to the Option 3 operation. For example, if other Options are additionally configured in addition to the Option 3 operation, in order to prevent operation conflicts with other Options, when the C-DRX on-duration is exceeded, the terminal may stop PDCCH monitoring regardless of whether the timer has expired.

[0225] The above Option 3 operation mode can only be applied to C-DRX on-duration. Therefore, the existing Option 1 operation mode can be applied outside of on-duration.

[0226] More specifically, the Option 1 operation mode is applied to operations related to C-DRX, and active state transition or sleep state maintenance can be performed in C-DRX on-duration. In addition, if the terminal transitions to the active state in C-DRX on-duration (or if the drx-onDuration timer starts), Option 3-A can be additionally applied to perform only LP-WUS monitoring instead of PDCCH monitoring.

[0227] Alternatively, Option 3-B can be additionally applied even when the terminal is in sleep state (when the drx-onDuration timer has not started) in C-DRX on-duration according to Option 1 operation mode. In this case, the terminal performs LP-WUS monitoring and can temporarily switch to active state when necessary.

[0228] FIG. 18a and FIG. 18b are conceptual diagrams illustrating a combination of Option 1 and Option 3 (more specifically, Option 3-B) according to one embodiment of the present invention.

[0229] Referring to FIGS. 18a and 18b, Option 1 may be applied in operations linked with C-DRX. If C-DRX maintains a sleep state, Option 3-B may additionally be applied in the on-duration. Power consumption of the terminal can be reduced through the Option 1 operation mode. In addition, even if the sleep state is maintained in the C-DRX on-duration, a slight increase in power consumption may be expected by performing LP-WUS monitoring in the LP-WUS occasion(s) within the C-DRX on-duration. However, this allows for a faster response to data transmission and reception that may occur suddenly, and as a result, the effect of reducing latency can be obtained.

[0230] Referring to Fig. 18a, the duty cycles and related setting values ​​(e.g., time position, period, time length, offset, etc.) for LP-WUS ocasion(s) according to Option 1 and LP-WUS ocasion(s) according to Option 3-B can be set via the same parameters. In this case, the same LP-WUS sequence can be applied. On the other hand, referring to Fig. 18b, the duty cycles and related setting values ​​for LP-WUS ocasion(s) according to Option 1 and the duty cycles and related setting values ​​for LP-WUS ocasion(s) according to Option 3-B can have different values ​​and can be set individually via different parameters. In this case, the same LP-WUS sequence can be applied, or different LP-WUS sequences can be applied.

[0231] In the embodiments of FIGS. 18a and 18b, a case in which Option 1 and Option 3-B are combined is described. However, a method in which Option 1 and Option 3-A are combined can also be applied.

[0232] As described above, when two or more Options are used in combination, it can be assumed that the operation of Option 1 is applied by default. Therefore, when the Options are independently set through different parameters, it is preferable that a parameter set for setting the operation mode of another Option (e.g., Option 2, Option 3-A, or Option 3-B) is optionally added to the parameter set for setting the operation mode of Option 1.

[0233] More specifically, when Option 3 (Option 3-A or Option 3-B) is additionally set to Option 1, the cycle of Option 3 can be set to be the same as the cycle of Option 1 without a separate setting. When the same cycle as the cycle of Option 1 is applied, the start time of the LP-WUS ocassion for LP-WUS monitoring for each cycle can be set to be the same as the on-duration start time of the C-DRX. Alternatively, it can be set by applying an offset to the on-duration start time.

[0234] When multiple LP-WUS occasions are set, a combination of a separate cycle from the start time of the LP-WUS occasion and the number of LP-WUS occasions or the end time of LP-WUS monitoring can be set. Specifically, a combination of {start time, separate cycle, number} or {start time, separate cycle, end time} can be set.

[0235] The above-described method is applicable only within the C-DRX on-duration. However, in cases where the on-duration is short (e.g., a short drx-onDuration timer), the time required to transition from sleep mode to active mode may occupy a majority of the on-duration. This may render PDCCH monitoring via LP-WUS monitoring inefficient.

[0236] So only if the length of the on-duration is greater than a certain threshold (e.g., the drx-onDuration timer It may be desirable to apply the method (threshold value). In this case, a specific threshold value may be defined in advance in the specification or may be set in advance by being included in the LP-WUS configuration information.

[0237]

[0238] Option 4

[0239] LP-WUS can operate independently without linking with C-DRX. That is, the terminal can remain in sleep state or switch to active state depending on whether LP-WUS is detected, regardless of whether C-DRX is set ('Option 4' in the description below).

[0240] More specifically, if a terminal detects LP-WUS in an LP-WUS occasion while in a sleep state, regardless of whether C-DRX is set, it can transition to an active state. A terminal that transitions to an active state can perform PDCCH monitoring and perform data transmission and reception operations based on scheduling information. In addition, a terminal that transitions to an active state by LP-WUS can return to a sleep state under various conditions, in the same manner as described in Option 2.

[0241] FIG. 19a and FIG. 19b are conceptual diagrams illustrating Option 4 according to one embodiment of the present invention.

[0242] Referring to FIGS. 19a and 19b, the terminal can monitor the configured LP-WUS occasion(s) at any time regardless of whether C-DRX is configured, and can switch to the active state when LP-WUS is detected.

[0243] Figure 19a illustrates an example in which a terminal that has transitioned to an active state is transitioned back to a sleep state by a timer. Conversely, Figure 19b illustrates an example in which a terminal that has transitioned to an active state is transitioned to a sleep state by a separate indicator (e.g., Rel-17 PDCCH skipping).

[0244]

[0245] Enable / disable and activate / deactivate LP-WUS operation

[0246] After information related to LP-WUS operation (e.g., LP-WUS monitoring-related settings, etc.) is set, LP-WUS operation can be enabled or disabled depending on the system situation. At this time, the enabling and disabling settings can be explicitly performed through separate indicators. For example, it can be indicated through DCI, MAC CE, system information (e.g., cell-specific RRC), or UE-specific RRC signaling.

[0247] Alternatively, enabling or disabling LP-WUS operation can be implicitly performed by determining whether LP-WUS monitoring is enabled. Specifically, if configuration information for LP-WUS monitoring is transmitted, the terminal can determine that LP-WUS monitoring is enabled, and if configuration information is not transmitted, the terminal can determine that LP-WUS monitoring is disabled.

[0248] After LP-WUS operation is enabled, it can be activated or deactivated depending on the base station conditions. In RRC CONNECTED mode, the terminal can perform various measurements, such as RRM (radio resource measurement) measurements, through MR instead of LP-WUR. This allows the terminal to more accurately monitor channel conditions, etc., and flexibly adjust the activation and deactivation of LP-WUS operation based on these conditions.

[0249] For example, when channel conditions deteriorate, LP-WUS may have relatively limited coverage compared to the existing downlink channel, potentially making reception unguaranteed. In such situations, LP-WUS operation can be disabled to prevent malfunctions due to LP-WUS reception failure.

[0250] Activation and deactivation of LP-WUS can be explicitly indicated via RRC, MAC CE, or DCI signaling. In this case, a 1-bit indicator indicating activation or deactivation can be used. Alternatively, activation or deactivation can be implicitly set based on specific conditions.

[0251] Among explicit instruction methods, RRC signaling can be difficult to adapt to channel conditions due to its difficulty in dynamic signaling. In contrast, MAC CE or DCI signaling allows for more adaptive response than RRC signaling. When signaling using DCI, the information can be transmitted via a terminal-specific PDCCH or a common PDCCH.

[0252] In the case of a UE-specific PDCCH, it can be monitored through a UE-specific search space (or cell-specific search space). In this case, a bit field can be added to the DCI transmitting UE scheduling information (e.g., DCI format 0_X or DCI format 1_X, etc.) to signal a 1-bit instruction indicating activation or deactivation of the LP-WUS operation. When activation or deactivation of the LP-WUS operation is indicated through the DCI transmitting UE scheduling information, the UE can perform an operation according to the corresponding scheduling information and then activate or deactivate the LP-WUS operation after a predetermined period of time.

[0253] In the case of a common PDCCH, DCI (e.g., DCI format 2_X, etc.) monitored through a cell-specific search space can be individually activated and deactivated by adding a bit field consisting of multiple bits to each terminal or terminal group by allocating 1 bit to each terminal or terminal group.

[0254] In the conditional method, the terminal can activate or deactivate the LP-WUS operation when the measured value satisfies or does not satisfy a specific threshold condition set in advance during the channel status monitoring process such as RSRP, RSSI, RSRQ, SINR measurement. For example, if the RSRP measurement value falls below a specific threshold set in advance, the channel status may be determined to be poor and LP-WUS reception cannot be guaranteed, and the LP-WUS operation may be deactivated. In this case, the terminal can continue to monitor PDCCH through MR without performing the LP-WUS monitoring operation. Accordingly, the power consumption of the terminal may increase, but malfunction due to LP-WUS reception failure can be prevented. Afterwards, if the RSRP measurement value recovers to above a specific threshold, the LP-WUS operation can be activated to reduce the power consumption of the terminal.

[0255] The channel state measurements, such as the RSRP described above, may be measured by LP-WUR or MR, or may be measured by both LP-WUR and MR. More specifically, if the channel state measurements are performed only through LP-WUR, in order to disable (or exit) the LP-WUS monitoring operation, the LP-WUS monitoring operation may be disabled when the LP-WUR measurement value is lower than a certain threshold, and the MR operation may be woken up to switch to the MR operation mode.

[0256] When the MR is in operation, in order to activate (or enter) the LP-WUS monitoring operation, if the channel state measurement value measured by the MR is higher than a certain threshold, the channel state can be judged to be sufficiently good, so the MR operation can be switched to sleep mode and the LP-WUS monitoring operation can be activated. In addition, the channel state measurement value measured by the LP-WUR can be additionally considered in the judgment in addition to the channel state measurement value measured by the MR.

[0257] Even if the channel state measurement by MR is sufficiently good, the measurement by LP-WUR may be bad. However, since LP-WUS monitoring is performed through LP-WUR, LP-WUS monitoring can be activated only when the channel state measurement measured by LP-WUR as well as MR is better than a certain threshold. In this case, the threshold value compared to the channel state measurement by MR and the threshold value compared to the channel state measurement by LP-WUR can be set differently. In addition, it can be set based on a specific threshold value and offset for either of the two (LP-WUR or MR).

[0258] In the case of LP-WUR, it can be divided into OOK (on-off keying) based LP-WUR (OOK-based LP-WUR) and OFDM-based LP-WUR (OFDM-based LP-WUR) depending on the type. OOK-based LP-WUR is a type that can receive only OOK symbols, and OFDM-based LP-WUR is a type that can receive both OOK symbols and OFDM symbols. Since channel state measurement performance may differ depending on the receiver type, it may be desirable to set a threshold value for each LP-WUR type. In addition, the threshold value for disabling the LP-WUS monitoring operation may be set differently from the threshold value for activating the LP-WUS monitoring operation.

[0259] Alternatively, a timer can be used to determine whether LP-WUS operation is enabled or disabled. For example, a timer can be started when LP-WUS operation is enabled, and automatically disabled after a preset period of time. If LP-WUS is detected during LP-WUS operation, the timer can be reset and restarted to extend the LP-WUS operation. Alternatively, the expiration time of an existing timer can be extended to continue the LP-WUS operation.

[0260] Another timer-based method is to disable the LP-WUS operation if LP-WUS detection is not performed for a certain period of time based on the timer while the LP-WUS operation is enabled, assuming that the channel condition is poor and LP-WUS reception is difficult. In this case, PDCCH monitoring can be performed through MR after the LP-WUS operation is disabled. On the other hand, if LP-WUS is detected while the timer is running, the activation time of the LP-WUS operation can be extended by resetting or extending the timer.

[0261] Conditions (e.g., threshold values) or timer values ​​for activating or deactivating the above LP-WUS operation can be set in advance through system information or terminal-specific RRC signaling.

[0262] The above-described methods can be applied not only to activating and deactivating LP-WUS operations, but also to enabling and disabling the LP-WUS function itself.

[0263] If LP-WUS is detected and PDCCH monitoring is initiated, LP-WUS operation may be disabled. Alternatively, LP-WUS operation may continue regardless of whether PDCCH monitoring is performed. Even if LP-WUS is not detected during LP-WUS operation, LP-WUS operation may be disabled when performing uplink transmissions such as preset Configured Grant (CG) PUSCH, SRS transmission, or downlink reception such as Semi-Persistent Scheduling (SPS), measurement, etc.

[0264] Even when LP-WUS operation is disabled, LP-WUS operation can be re-enabled after a specific period of time determined by a timer or when a PDCCH skipping command is received.

[0265] Even when the LP-WUS monitoring operation is disabled, it can be enabled upon request from the terminal. When the terminal completes a transmission and reception operation and no further transmission or reception operation is expected, the terminal can request the base station to enable the LP-WUS monitoring operation to reduce power consumption. The terminal can request the enabling of the LP-WUS monitoring operation through UCI, MAC CE, or RRC signaling, and the request can be transmitted through an uplink signal and channel such as PRACH, SRS, SR, PUCCH, or PUSCH.

[0266] More specifically, for PRACH, it may be appropriate to use a Contention-Free Random Access (CFRA) scheme for specific random access occasions (ROs). To achieve this, specific ROs and PRACH preambles are allocated to UEs, and this information can be preset via system information or UE-specific RRC signaling.

[0267] For SRS or SR, specific SRS or SR resources can be configured to enable LP-WUS operation. This can also be configured in advance via system information or terminal-specific RRC signaling.

[0268] Additionally, for UCI, MAC CE, or RRC signaling transmitted via PUCCH or PUSCH, an indicator (e.g., a 1-bit indicator) for requesting LP-WUS operation enablement may be included in the UCI, MAC CE, or RRC signaling and transmitted.

[0269]

[0270] The coverage of LP-WUS can be assumed to be the same as the coverage of PDCCH for paging, or it can be assumed to be the same as the coverage of Msg3 PUSCH. If the coverage of LP-WUS is assumed to be the same as the coverage of PDCCH for paging, LP-WUS can be considered to cover the entire cell. On the other hand, if the coverage of LP-WUS is assumed to be the same as the coverage of Msg3 PUSCH, LP-WUS can be considered to not cover the entire cell but only a part of it. If LP-WUS does not cover the entire cell but only a part of it, a UE outside the coverage of LP-WUS may not be able to receive LP-WUS and thus may not be able to operate in power saving mode. In addition, if a UE operating in power saving mode is outside the coverage of LP-WUS, it may not be able to switch from sleep to active state in C-DRX on-duration because it may not be able to receive LP-WUS. In such a situation, the terminal may not be able to perform data transmission and reception operations at an appropriate time, resulting in a decrease in data transmission and reception efficiency.

[0271] Therefore, in cases where LP-WUS does not cover the entire cell, the base station can configure and use Rel-16 DCP and LP-WUS simultaneously as a way to resolve this. More specifically, a terminal within the LP-WUS coverage can determine whether to transition from C-DRX On-Duration to the Active state through LP-WUS monitoring (i.e., Option 1 operation mode). On the other hand, a terminal outside the LP-WUS coverage can determine whether to transition from C-DRX On-Duration to the Active state through PDCCH monitoring including a wake-up / sleep indication (i.e., Rel-16 DCP).

[0272] A UE outside the LP-WUS coverage area may not be able to distinguish whether the reason for not receiving an LP-WUS is because it is outside the LP-WUS coverage area or because the LP-WUS was not transmitted. Therefore, it may be desirable for a UE outside the LP-WUS coverage area to perform both LP-WUS monitoring and PDCCH (e.g., PDCCH format 2_6) monitoring of Rel-16 DCP. Alternatively, depending on the situation, it may be more appropriate for a UE outside the LP-WUS coverage area to perform only PDCCH monitoring of Rel-16 DCP.

[0273] Whether the terminal performs only LP-WUS monitoring, both LP-WUS monitoring and PDCCH monitoring of Rel-16 DCP, or only PDCCH monitoring of Rel-16 DCP can be determined based on various values ​​measured by the terminal (e.g., RSRP, RSSI, RSRQ, SNR, SINR, etc.). More specifically, it can be determined based on whether these values ​​satisfy a specific threshold (e.g., whether the measured value is greater than or equal to the threshold). In this case, the specific threshold can be defined in advance, or an appropriate value can be set according to the system environment and transmitted to the terminal. Alternatively, it can be set in advance through system information or terminal-specific RRC signaling.

[0274] Alternatively, the terminal can sequentially monitor the PDCCH of LP-WUS and Rel-16 DCP. More specifically, the terminal may first monitor LP-WUS, and if LP-WUS is detected, perform PDCCH monitoring of Rel-16 DCP via MR. At this time, if the PDCCH indicates wake-up (=1), the terminal can switch to the active state and perform operations such as PDCCH monitoring. On the other hand, if the PDCCH indicates sleep (=0), the terminal can maintain the sleep state to reduce power consumption.

[0275] If the coverage of LP-WUS is smaller than the entire cell coverage, terminals within LP-WUS coverage can determine whether to monitor the PDCCH of the Rel-16 DCP through LP-WUS monitoring. However, terminals outside LP-WUS coverage may not be able to distinguish between cases where LP-WUS is not transmitted and thus not detected and cases where it is outside LP-WUS coverage and thus not detected.

[0276] To address this, it may be desirable to set the default behavior to remain in a sleep state when LP-WUS is detected. For example, regardless of LP-WUS coverage, a terminal that detects LP-WUS can remain in its existing sleep state. Conversely, a terminal that does not detect LP-WUS can perform PDCCH monitoring in the Rel-16 DCP method via MR.

[0277] In this case, a terminal within the LP-WUS coverage can determine an action based on whether LP-WUS is detected. If LP-WUS is detected, the terminal remains in a sleep state and does not perform PDCCH monitoring of the Rel-16 DCP. On the other hand, if LP-WUS is not detected, the terminal can perform PDCCH monitoring of the Rel-16 DCP through MR and determine whether to switch from C-DRX on-duration to the active state. A terminal outside the LP-WUS coverage cannot detect LP-WUS and therefore only performs PDCCH monitoring of the Rel-16 DCP, which can be used to determine whether to switch from C-DRX on-duration to the active state.

[0278] In case LP-WUS is not detected due to insufficient LP-WUS coverage or other various circumstances, the base station may need to verify that the LP-WUS operation is being performed correctly by the terminal (or group of terminals) to prevent malfunctions. In addition, since the LP-WUS operation in the RRC CONNECTED state is likely to operate in a terminal-specific mode, it may be necessary to verify that the time, frequency, and code resources set for each terminal are being used appropriately without waste. Accordingly, a terminal capable of transmitting and receiving via MR in the RRC CONNECTED state can transmit a confirmation message to the base station when the LP-WUS operation is activated or deactivated by the base station.

[0279] If the activation or deactivation of LP-WUS operation is set via higher-layer signaling, such as RRC or MAC CE, the UE can replace the acknowledgement message using HARQ ACK / NACK feedback information for PDSCH reception containing higher-layer information. For example, if the UE reports ACK information for a PDSCH containing higher-layer information (such as RRC or MAC CE) indicating LP-WUS activation or deactivation, the base station can determine that the UE has correctly received the indication information.

[0280] When the LP-WUS operation is activated or deactivated via the PDCCH, the HARQ ACK / NACK feedback information can be used to replace the confirmation message. For example, if the terminal transmits an ACK signal for the PDCCH, the base station can determine that the terminal has correctly received the LP-WUS operation activation or deactivation indicator. This method is mainly applicable when the LP-WUS operation activation or deactivation is indicated via a common PDCCH that can be monitored by multiple terminals. In this case, it is desirable to configure the HARQ ACK / NACK feedback of the terminal or terminal group to be distinguished at the base station in order to individually report whether a specific terminal or terminal group has successfully received the corresponding PDCCH.

[0281] For example, if a specific terminal or terminal group reports ACK information and another specific terminal or terminal group reports NACK information, the base station may determine that the terminal or terminal group reporting the NACK information did not correctly receive the activation or deactivation information. Even if ACK or NACK information is not reported, the base station may determine that PDCCH reception has failed, and may consider that the terminal or terminal group did not correctly receive the activation or deactivation information. Alternatively, if the LP-WUS operation is activated or deactivated through the PDCCH including the terminal's downlink scheduling information, the terminal may replace the confirmation message using HARQ ACK / NACK feedback information for the data received according to the scheduling information.

[0282] In this case, if the terminal reports ACK information, the base station can determine that the terminal not only successfully received data but also correctly received LP-WUS activation or deactivation instruction information. On the other hand, if the terminal reports NACK information, the base station can determine that data reception failed but LP-WUS activation or deactivation instruction information was correctly received. Similarly, if LP-WUS operation activation or deactivation is indicated through a PDCCH including uplink scheduling information of the terminal, and the terminal performs uplink transmission according to the uplink scheduling information, the base station can determine that the terminal correctly received the LP-WUS operation instruction information.

[0283] If the LP-WUS operation is activated or deactivated based on a pre-established condition (e.g., a measurement value or a timer), it is necessary to report to the base station when the condition is satisfied and the LP-WUS operation is activated or deactivated. At this time, information for reporting (e.g., a confirmation message) can be transmitted through uplink channels and signals such as PRACH, PUCCH, PUSCH, SR, and SRS in the form of UCI, MAC CE, or RRC signaling.

[0284] After the LP-WUS operation is activated, it may also be necessary for the LP-WUR to report whether the LP-WUS detection was successful. In this case, it may be desirable for the LP-WUS sequence to indicate a state other than wake-up or sleep (e.g., the initiation or starting point of the LP-WUS operation). When the LP-WUS operation of a terminal is activated, the base station may preferentially transmit to the terminal an LP-WUS sequence indicating the initiation or starting point of the LP-WUS operation, instead of a sequence indicating the wake-up or (if supported) sleep state. The terminal detecting this may report it to the base station via the uplink channel and signal according to the method described above.

[0285] In the invention described above, the entity that performs the operation such as switching to an active state, maintaining a sleep state, or switching to an active state and then returning to a sleep state depending on whether LP-WUS is detected may be a terminal or a group of terminals. These operation entities may be preset by the system. If each terminal performs the operation individually, the LP-WUS sequence may indicate the RNTI value or UE ID of each terminal. In this case, the effect of improving power consumption of each terminal may be significant, but since signaling must be performed for each terminal, signaling overhead may increase significantly.

[0286] When grouping multiple terminals and performing operations for each terminal group, the LP-WUS sequence may represent a pre-configured UE group ID or a portion of the MSB (most significant bits) of the UE ID. This method may have a lower power consumption improvement effect than performing signaling for each individual terminal, but allows for more efficient signaling. When the LP-WUS sequence represents a UE group ID, each LP-WUS sequence may be set to correspond to each UE group ID, and additionally, a specific LP-WUS sequence may be set to correspond to all UE group IDs. When the LP-WUS sequence represents a portion of the MSB of the UE ID, all terminals whose MSB of the terminal ID matches the LP-WUS sequence may be determined to have detected LP-WUS. For example, if the UE ID consists of 16 bits and the LP-WUS sequence signals only 12 bits, all terminals (up to 16 terminals separated by 4 LSB bits) whose MSB 12 bits of the UE ID match the LP-WUS sequence can be determined to have detected LP-WUS. Afterwards, depending on the settings, actions such as transitioning to active state, maintaining sleep state, or transitioning to active state and then returning to sleep state can be performed.

[0287] Methods for performing terminal grouping include a grouping method by CN (Core Network) that assigns terminal groups by considering terminal characteristics (e.g., mobility pattern, paging probability, etc.), a grouping method based on UE ID that groups terminals with similar UE ID values, or a method for performing terminal grouping through mathematical operations such as modulo operations.

[0288] When the LP-WUS sequence is transmitted as a combination of an OOK sequence and an OFDM-overlaid sequence, it may be desirable to map the MSB of the entire information to the OOK sequence. In this case, a terminal that can only detect the OOK sequence can detect only the MSB of the entire information, determine that it corresponds to itself, and wake up. However, because it relies solely on the MSB information, it is possible that more terminals will wake up than originally intended.

[0289] Meanwhile, terminals capable of detecting OFDM-overlapping sequences can detect both the OOK sequence and the OFDM-overlapping sequence, acquire complete information, and then determine whether to wake up. Therefore, only a more specific and limited number of terminals are awakened than when detecting only the OOK sequence.

[0290] In this way, when the MSB of the entire information is mapped to the OOK sequence and the remaining information is mapped to the OFDM-overlapping sequence and transmitted, some unnecessary terminals may wake up due to terminals that only detect the OOK sequence and wake up. However, this method can prevent situations where terminals that should wake up do not wake up due to incorrect information transmission.

[0291] Alternatively, the OFDM-overlap sequence can be transmitted as a repetition of the information transmitted via the OOK sequence. In this case, the OFDM-based LP-WUR terminal can receive both the OOK sequence and the OFDM-overlap sequence, which can improve reception performance. Alternatively, the information transmitted via the OOK sequence can be transmitted only through some of the preceding OFDM-overlap sequences. In this case, the OFDM-based LP-WUR terminal can acquire relevant information faster than the OOK-based LP-WUR terminal.

[0292] In order to perform LP-WUS operations by distinguishing terminals or terminal groups, different LP-WUS monitoring occasions(es) can be set for different terminals or terminal groups, or different time and frequency resources can be allocated. Alternatively, if LP-WUS can have multiple OOK patterns, different LP-WUS OOK patterns corresponding to RNTI, UE ID, UE group ID, or part of UE ID can be assigned to each terminal or terminal group. These methods can be used alone or in combination to perform differentiated LP-WUS operations by terminal or terminal group.

[0293] Additionally, in the present invention, all settings related to LP-WUS operation can be set statically, semi-statically, or dynamically through system information, terminal-specific RRC signaling, or control information transmitted through a control channel.

[0294] During the LP-WUS operation, uplink transmissions may be performed by the terminal rather than by the base station scheduling, such as SR, PRACH, CG PUSCH, and CSI reporting, or may be preset by the base station. In such cases, it may be desirable for the terminal to switch to an active state and perform uplink transmission regardless of whether or not the base station detects LP-WUS transmitted.

[0295] The terminal can initiate a wake-up operation of the MR for transitioning to the active state, regardless of LP-WUS, at an appropriate time, considering the uplink transmission timing and the time required to transition to the active state. After completing the uplink transmission, the terminal can return to the sleep state and perform LP-WUS monitoring operations.

[0296] At this time, the offset value from the point in time when the LP-WUS monitoring operation for uplink transmission is stopped and the active state transition begins until the actual uplink transmission is performed, and the offset value from the point in time when the LP-WUS monitoring operation is started again after the uplink transmission is completed, may be the same or different. The offset value may be predefined in the specification as a specific value, or may be set through system information or RRC signaling. In addition, the terminal may implement wake-up operations and transitions to sleep states.

[0297] FIG. 20 is a conceptual diagram for explaining an operation in which a terminal performs uplink transmission while performing LP-WUS monitoring according to one embodiment of the present invention.

[0298] Referring to FIG. 20, when a terminal performs LP-WUS monitoring and uplink transmission is required by the terminal rather than by base station scheduling, the terminal may skip LP-WUS monitoring from an appropriate time considering the uplink transmission timing and the time required for active state transition for this (e.g., MR wake-up time), perform MR wake-up, and then perform uplink transmission through the MR. The terminal that has completed uplink transmission may switch to a sleep state and resume LP-WUS monitoring operation. In this case, the terminal that has switched to an active state for uplink transmission may perform not only uplink transmission but also PDCCH monitoring.

[0299] In addition to uplink transmission, when the terminal must perform downlink reception without separate scheduling, such as measurement through fixed or semi-fixed CSI-RS, SSB, etc., or SPS, it is desirable for the terminal to perform downlink reception by switching to the active state regardless of whether LP-WUS transmitted from the base station is detected. The terminal can initiate the wake-up operation of the MR for active state transition regardless of LP-WUS at an appropriate time considering the downlink reception time and the time required for active state transition. After completing downlink reception, the terminal can switch back to the sleep state and resume LP-WUS monitoring operation.

[0300] At this time, the offset value from the point in time when the LP-WUS monitoring operation for downlink reception is stopped and the transition to the active state is started until the actual downlink reception is performed, and the offset value until the point in time when the LP-WUS monitoring operation is performed again after the downlink reception is completed, may be the same or different. This offset value may be predefined in the specification as a specific value, or may be set through system information or RRC signaling. In addition, the terminal may implement wake-up operations and transitions to the sleep state.

[0301] The transition time illustrated in the above embodiment refers to the time required to wake up the MR to perform a transmission / reception operation via the MR, or the time required to switch the MR to a sleep state after the MR transmission / reception is completed. This can be applied equally to all embodiments other than the present embodiment, but has been omitted for the sake of brevity of explanation.

[0302] The operations of the method according to an embodiment of the present invention can be implemented as a computer-readable program or code on a computer-readable recording medium. A computer-readable recording medium includes any type of recording device that stores information readable by a computer system. Furthermore, a computer-readable recording medium can be distributed across network-connected computer systems, allowing the computer-readable program or code to be stored and executed in a distributed manner.

[0303] Additionally, the computer-readable recording medium may include hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, etc. The program instructions may include not only machine language codes produced by a compiler, but also high-level language codes that can be executed by a computer using an interpreter, etc.

[0304] While some aspects of the present invention have been described in the context of a device, they may also represent a description of a corresponding method, wherein a block or device corresponds to a method step or a feature of a method step. Similarly, aspects described in the context of a method may also be described as a corresponding block or item or a feature of a corresponding device. Some or all of the method steps may be performed by (or using) a hardware device, such as, for example, a microprocessor, a programmable computer, or an electronic circuit. In some embodiments, at least one or more of the most important method steps may be performed by such a device.

[0305] In embodiments, a programmable logic device (e.g., a field-programmable gate array) may be used to perform some or all of the functions of the methods described herein. In embodiments, the field-programmable gate array may operate in conjunction with a microprocessor to perform one of the methods described herein. In general, the methods are preferably performed by some hardware device.

[0306] Although the present invention has been described above with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various modifications and changes may be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below.

Claims

1. By the terminal's operating method, A step of receiving setting information of a low-power wake-up signal (LP-WUS) from a base station; When the terminal is in a sleep state, a step of performing an operation of monitoring the LP-WUS in the LP-WUS ocasion(s) set according to the setting information of the LP-WUS; and If the above LP-WUS is detected, a step of switching to an active state is included, The above LP-WUS occasion(s) are set independently from the C-DRX (connected discontinuous reception) on-duration, and the terminal performs PDCCH (physical data control channel) monitoring in the active state. How the terminal operates.

2. In claim 1, The configuration information of the above LP-WUS is received through the main radio (MR) module of the terminal, and the LP-WUS is monitored through the wake-up radio (WUR) module of the terminal. How the terminal operates.

3. In claim 1, LP-WUS ocasion(s) are set at predetermined intervals within and outside the C-DRX on-duration, or are set with a predetermined offset from the start time of the C-DRX on-duration. How the terminal operates.

4. In claim 3, Information about the above-mentioned predetermined cycle is included in the setting information of the LP-WUS. How the terminal operates.

5. In claim 3, The terminal monitors the LP-WUS in the LP-WUS ocasion(s) set outside the C-DRX on-duration and the LP-WUS ocasion(s) set within the C-DRX on-duration. How the terminal operates.

6. In claim 1, The above LP-WUS is composed of an OOK (on-off shift keying) sequence or an OFDM-overlaid sequence. How the terminal operates.

7. In claim 1, A timer with a predetermined value is started at the time when the terminal switches to the active state, and when the timer expires, the terminal switches from the active state to the sleep state, and the timer is a separate timer from a timer defining C-DRX on-duration. How the terminal operates.

8. In claim 1, It further includes a step of transmitting a capability report to the base station, The above capability report includes information about the time required for the terminal to transition from the sleep state to the active state. How the terminal operates.

9. In claim 1, If the terminal is configured to perform periodic RSRP (reference signal received power) and / or CSI (channel state information) reporting, the terminal performs the periodic RSRP and / or CSI reporting even in the sleep state. How the terminal operates.

10. In claim 1, The terminal activates or deactivates the operation of monitoring the LP-WUS based on the measurement result of the channel status or signaling from the base station. How the terminal operates.

11. In claim 10, The signaling is performed based on at least one of DCI (downlink control information), MAC-CE (medium access control-control element), or RRC (radio resource control) message, and when the signaling is received, the terminal transmits a confirmation message for the signaling to the base station. How the terminal operates.

12. As a method of operation of the base station, A step of transmitting setting information of a low-power wake-up signal (LP-WUS) to the terminal; and When the terminal is in a sleep state, a step of performing an operation of transmitting LP-WUS to the terminal in LP-WUS ocasion(s) set according to the setting information of the LP-WUS is included. When the terminal detects the LP-WUS, the terminal switches to an active state, and the LP-WUS occasion(s) are set independently from a C-DRX (connected discontinuous reception) on-duration, and the LP-WUS causes the terminal to perform PDCCH (physical data control channel) monitoring in the active state. How the base station operates.

13. In claim 12, LP-WUS ocasion(s) are set at predetermined intervals within and outside the C-DRX on-duration, or are set with predetermined offsets from the start of the C-DRX on-duration. How the base station operates.

14. In claim 13, Information about the above-mentioned predetermined cycle is included in the setting information of the LP-WUS. How the base station operates.

15. In claim 12, The terminal monitors the LP-WUS in the LP-WUS ocasion(s) set outside the C-DRX on-duration and the LP-WUS ocasion(s) set within the C-DRX on-duration. How the base station operates.

16. In claim 12, It further includes a step of receiving a capability report from the terminal, The above capability report includes information about the time required for the terminal to transition from the sleep state to the active state. How the base station operates.

17. At the terminal, At least one processor; main radio (MR) module; and Includes a wake-up radio (WUR) module, At least one processor of the terminal: A step of receiving setting information of a low-power wake-up signal (LP-WUS) from a base station through the main radio module; When the terminal is in a sleep state, a step of performing an operation of monitoring the LP-WUS in the LP-WUS ocasion(s) set according to the setting information of the LP-WUS through the wake-up radio module; and If the above LP-WUS is detected, a step for switching to an active state is performed, The above LP-WUS occasion(s) are set independently from the C-DRX (connected discontinuous reception) on-duration, and the terminal performs PDCCH (physical data control channel) monitoring in the active state. Terminal.

18. In claim 17, LP-WUS ocasion(s) are set at predetermined intervals within and outside the C-DRX on-duration, or are set with a predetermined offset from the start time of the C-DRX on-duration. Terminal.

19. In claim 18, The terminal monitors the LP-WUS in the LP-WUS ocasion(s) set outside the C-DRX on-duration and the LP-WUS ocasion(s) set within the C-DRX on-duration through the wake-up radio module. Terminal.

20. In claim 17, The at least one processor activates or deactivates an operation of monitoring the LP-WUS based on a measurement result of a channel state or a signaling from the base station. Terminal.

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