Method performed by terminal or network and device therefor in wireless communication system

Abstract

A terminal according to an embodiment of the present disclosure may: receive information about switching from a first pattern to a second pattern among a plurality of patterns related to transmission of a burst including a plurality of synchronization signal (SS) blocks; and receive at least one second SS block among a plurality of second SS blocks belonging to a second burst related to the second pattern. The terminal may acquire quasi co-location (QCL) information about at least one second SS block on the basis of at least one first SS block among a plurality of first SS blocks belonging to a first burst related to the first pattern.

Description

Method performed by a terminal or network in a wireless communication system and device therefor

[0001] The present disclosure relates to a wireless communication system, and more particularly, to a method and device for performing wireless communication between terminals or networks in a wireless communication system.

[0002] The 5G mobile communications system, the successor to LTE (long-term evolution), is a new, clean-slate mobile communications system characterized by high performance, low latency, and high availability. 5G NR can utilize all available spectrum resources, from low-frequency bands below 1 GHz, to intermediate-frequency bands between 1 GHz and 10 GHz, and high-frequency (millimeter wave) bands above 24 GHz. 6G mobile communications systems are being developed based on the underlying technologies of 5G mobile communications.

[0003] In the existing NR standard, SS / PBCH block (SSB) bursts are periodically established, and within each SSB burst, SSBs of different indices are transmitted through beam sweeping. To facilitate multiplexing of DL / UL signals when other DL / UL signals need to be transmitted and received within an SSB burst, a time gap is established between SSBs of different indices.

[0004] In this way, according to the existing NR standard, the time required to complete the transmission of SSBs within an SSB burst is bound to increase due to the time gap set between SSBs, and this is disadvantageous from the perspective of saving network energy because the time the base station must stay awake increases even when there is no DL / UL traffic or no terminals.

[0005] The technical problem to be achieved in the present disclosure is to provide a method for efficiently performing a wireless signal transmission and reception process and a device therefor. As an example, a plurality of SS (and / or PBCH) burst patterns including an SS (and / or PBCH) burst pattern having a more power-efficient structure and an operation method of a terminal / network related thereto are provided.

[0006] In addition to the technical challenges described above, other technical challenges can be inferred from the description below.

[0007] According to one aspect of the present disclosure, a method performed by a terminal includes receiving information about switching from a first pattern to a second pattern among a plurality of patterns related to transmission of a burst including a plurality of synchronization signal (SS) blocks; and receiving at least one second SS block among a plurality of second SS blocks belonging to a second burst related to the second pattern, wherein the terminal can obtain quasi co-location (QCL) information for the at least one second SS block based on the at least one first SS block among the plurality of first SS blocks belonging to the first burst related to the first pattern.

[0008] The terminal can determine at least one first SS block to provide the QCL information to at least one second SS block based on the linkage between the plurality of first SS blocks and the plurality of second SS blocks.

[0009] The linkage between the plurality of first SS blocks and the plurality of second SS blocks may include a mapping between indices of the plurality of first SS blocks and indices of the plurality of second SS blocks.

[0010] Based on the fact that the SS block index within the first burst matches the SS block index within the second burst, the terminal can determine that the first SS block and the second SS block have a QCL relationship.

[0011] The terminal can determine that the plurality of first SS blocks sorted in SS block index order within the first burst have a QCL relationship with the plurality of second SS blocks sorted in SS block index order within the second burst.

[0012] Information about the above switching may include information about the index of the second pattern or the configuration of the second burst related to the second pattern.

[0013] Information about the configuration of the second burst may include information about indices of the plurality of second SS blocks transmitted within the second burst.

[0014] Information about the above switching can be received via downlink control information (DCI) or a physical downlink shared channel (PDSCH) scheduled by the DCI.

[0015] A first time length from the leading first SS block to the last first SS block within the first burst may be different from a second time length from the leading second SS block to the last second SS block within the second burst.

[0016] A first time gap between the plurality of first SS blocks within the first burst may be different from a second time gap between the plurality of second SS blocks within the second burst.

[0017] According to another aspect of the present disclosure, a non-transitory computer-readable recording medium having recorded thereon a program for performing the method described above may be provided.

[0018] According to another aspect of the present disclosure, a device comprises at least one processor; and at least one memory configured to store instructions that are executed by the at least one processor to cause the at least one processor to perform operations, wherein the operations of the processor include receiving information about a switching from a first pattern to a second pattern among a plurality of patterns related to transmission of a burst including a plurality of synchronization signal (SS) blocks; and receiving at least one second SS block among a plurality of second SS blocks belonging to a second burst related to the second pattern, wherein the device can obtain quasi co-location (QCL) information for the at least one second SS block based on at least one first SS block among the plurality of first SS blocks belonging to the first burst related to the first pattern.

[0019] The above device may be a terminal including a transceiver or a processing device configured to control the terminal.

[0020] According to another aspect of the present disclosure, a method performed by a base station includes transmitting information about switching from a first pattern to a second pattern among a plurality of patterns related to transmission of a burst including a plurality of synchronization signal (SS) blocks; and transmitting at least one second SS block among a plurality of second SS blocks belonging to a second burst related to the second pattern, wherein at least one first SS block among the plurality of first SS blocks belonging to a first burst related to the first pattern can have a quasi co-location (QCL) relationship with the at least one second SS block.

[0021] According to another aspect of the present disclosure, a base station comprises at least one processor; and at least one memory configured to store instructions that are executed by the at least one processor to cause the at least one processor to perform operations, wherein the operations of the processor include transmitting information about switching from a first pattern to a second pattern among a plurality of patterns related to transmission of a burst including a plurality of synchronization signal (SS) blocks; and transmitting at least one second SS block among a plurality of second SS blocks belonging to a second burst related to the second pattern, wherein at least one first SS block among the plurality of first SS blocks belonging to the first burst related to the first pattern can have a quasi co-location (QCL) relationship with the at least one second SS block.

[0022] According to the present disclosure, signal transmission and reception can be efficiently performed in a wireless communication system. For example, a plurality of SS (and / or PBCH) burst patterns including an SS (and / or PBCH) burst pattern having a more power-efficient structure are set / defined, and not only is an SS (and / or PBCH) burst configuration adaptive to a wireless channel environment possible through switching between the plurality of SS (and / or PBCH) burst patterns, but also the channel estimation burden of a terminal due to pattern switching can be alleviated through QCL assumption between different patterns.

[0023] In addition to the technical effects described above, other technical effects can be inferred from the description below.

[0024] Figure 1 illustrates a flexible network topology to which some examples of this specification may be applied.

[0025] FIG. 2 illustrates an example of a communication system applicable to the present disclosure.

[0026] FIG. 3 illustrates an example of a wireless device applicable to the present disclosure.

[0027] FIG. 4 illustrates a communication procedure between a first node (e.g., a terminal) and a second node (e.g., a base station) applicable to the present disclosure.

[0028] Figure 5 illustrates a general functional architecture for an AI / ML model.

[0029] Figure 6 illustrates a communication procedure between a first node (e.g., terminal) and a second node (e.g., base station) to which an AI / ML model is applied.

[0030] FIG. 7 illustrates an electromagnetic spectrum according to one embodiment of the present disclosure.

[0031] FIG. 8 illustrates an example of a procedure for transmitting system information for THz communication to which the present disclosure applies.

[0032] Figure 9 illustrates a beam management procedure applicable to the present disclosure.

[0033] FIG. 10 illustrates an example of a sensing operation according to one embodiment of the present disclosure.

[0034] FIG. 11 illustrates time / frequency resources for sensing operations according to one embodiment of the present specification.

[0035] FIG. 12 illustrates a procedure related to a sensing operation according to one embodiment of the present specification.

[0036] Figure 13 illustrates an example of the operation procedure of a base station supporting NES technology.

[0037] Figure 14 illustrates an example of a procedure for cell DTX / DRX operation.

[0038] Figure 15 illustrates an example of a procedure for CA operation using SSB-less SCell.

[0039] Figure 16 illustrates an example of a conditional handover (CHO) procedure.

[0040] Figure 17 illustrates an example of on-demand SSB transmission.

[0041] Figure 18 illustrates an SSB pattern (SSB burst) when the maximum number of SSB indices is 8.

[0042] Figures 19 to 26 illustrate SSB patterns (SSB bursts) according to various embodiments.

[0043] Figures 27 to 31 illustrate SS burst transmission and PBCH burst transmission according to various embodiments.

[0044] Figure 32 illustrates the operation of a terminal and a base station according to one embodiment.

[0045] Figure 33 illustrates a flow of a method performed by a terminal according to one embodiment.

[0046] Figure 34 illustrates a flow of a method performed by a base station according to one embodiment.

[0047] As used herein, "A or B" can mean "only A," "only B," or "both A and B." In other words, as used herein, "A or B" can be interpreted as "A and / or B." For example, as used herein, "A, B or C" can mean "only A," "only B," "only C," or "any combination of A, B and C."

[0048] As used herein, a slash ( / ) or a comma can mean "and / or." For example, "A / B" can mean "A and / or B." Accordingly, "A / B" can mean "only A," "only B," or "both A and B." For example, "A, B, C" can mean "A, B, or C."

[0049] In this specification, "at least one of A and B" may mean "only A", "only B" or "both A and B". Additionally, in this specification, the expressions "at least one of A or B" or "at least one of A and / or B" may be interpreted identically to "at least one of A and B".

[0050] Additionally, in this specification, “at least one of A, B and C” can mean “only A,” “only B,” “only C,” or “any combination of A, B and C.” Additionally, “at least one of A, B or C” or “at least one of A, B and / or C” can mean “at least one of A, B and C.”

[0051] Additionally, parentheses used herein may mean "for example." Specifically, when "control information (ABC)" is indicated, "ABC" may be described as an example of "control information." For example, "control information" may include DEF as another example. In other words, "control information" in this specification is not limited to "ABC," and "ABC" may be described as an example of "control information." Furthermore, even when indicated as "control information (i.e., ABC)," "ABC" may be described as an example of "control information."

[0052] Additionally, in this specification, terms such as “first,” “second,” etc. are used only for the purpose of distinguishing one component from another component and are not used to limit the components, and do not limit the order or importance between the components unless specifically limited. Accordingly, a first component in one embodiment of this specification may be referred to as a second component in another embodiment, and similarly, a second component in one embodiment may be referred to as a first component in another embodiment.

[0053] In the following explanation, ‘when, if, in case of’ can be replaced with ‘based on’.

[0054] Technical features individually described in a single drawing in this specification may be implemented individually or simultaneously.

[0055] In this specification, a terminal is a user equipment (UE) or a consumer-side device, and may also be referred to as a base station / second node / IAB node / first node that receives / transmits signals from / to a Transmission-Reception Point (TRP). A terminal may correspond to a physical node or a logical node. A terminal may correspond to an endpoint on the user side, or may correspond to an intermediate point between other endpoints. In communication between two points that are not limited to endpoints (including one-to-one / many-to-one / one-to-many / many-to-many communication), a terminal may correspond to a served node. A terminal may be a node with a fixed location, or a node with an unfixed location (or mobile).

[0056] In this specification, a base station (BS) is a device on the network side, and may also be called a second node / IAB node / x-NodeB (x-NodeB, x may be an abbreviation related to radio access technology (RAT)) / Transmission-Reception Point (TRP). A BS may correspond to a physical node or a logical node. A BS may correspond to an endpoint on the network side, or may correspond to an intermediate point between other endpoints. In communication between two points that are not limited to endpoints (including one-to-one / many-to-one / one-to-many / many-to-many communication), a BS may correspond to a serving node. A BS may be a node with a fixed location, or a node with an unfixed location.

[0057] In this specification, higher layer parameters may be set for the terminal, preset, or predefined. For example, the base station may transmit higher layer parameters to the terminal. For example, the terminal may transmit parameters such as capabilities to the base station as higher layer parameters. For example, the higher layer parameters may be transmitted via radio resource control (RRC) signaling or medium access control (MAC) signaling.

[0058] In this specification, the information / state / parameter being “configured or pre-configured” can be interpreted as the information / state / parameter being provided / pre-provided to the terminal through pre-defined signaling (e.g., SIB, MAC, RRC) from the base station. In this specification, the information / state / parameter being “defined or pre-defined” can be interpreted as the information / state / parameter being known in advance or pre-stored at the base station and the terminal without signaling between the base station and the terminal.

[0059] The technology described in this specification can be used in various wireless communication systems such as CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), and SC-FDMA (single carrier frequency division multiple access). CDMA can be implemented with wireless technologies such as UTRA (universal terrestrial radio access) or CDMA2000. TDMA can be implemented with wireless technologies such as GSM (global system for mobile communications) / GPRS (general packet radio service) / EDGE (enhanced data rates for GSM evolution). OFDMA can be implemented with wireless technologies such as IEEE (Institute of Electrical and Electronics Engineers) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, E-UTRA (evolved UTRA), LTE (long term evolution), and 5G NR.

[0060] The technology described in this specification can be implemented with 6G wireless technology and applied to various 6G systems. For example, the 6G system can have key factors such as enhanced mobile broadband (eMBB), ultra-reliable low latency communications (URLLC), massive machine-type communication (mMTC), artificial intelligence (AI) integrated communication, tactile internet, high throughput, high network capacity, high energy efficiency, low backhaul and access network congestion, and enhanced data security.

[0061] <Symbols, Abbreviations, Terms>

[0062] - PDCCH: Physical Downlink Control CHannel

[0063] - DCI: Downlink Control Information

[0064] - PDSCH: Physical Downlink Shared CHannel

[0065] - PUSCH: Physical Uplink Shared CHannel

[0066] - CSI: Channel state information

[0067] - RRM: Radio resource management

[0068] - SCS: Sub-carrier spacing

[0069] - RLM: Radio link monitoring

[0070] - DCI: Downlink Control Information

[0071] - CAP: Channel Access Procedure

[0072] - Ucell: Unlicensed cell

[0073] - TBS: Transport Block Size

[0074] - TDRA: Time Domain Resource Allocation

[0075] - SLIV: Starting and Length Indicator Value (This is an indicator value for the starting symbol index and number of symbols within the slot of the PDSCH and / or PUSCH, and can be set as a component of the entry that constitutes the TDRA field within the PDCCH that schedules the corresponding PDSCH and / or PUSCH.)

[0076] - BWP: BandWidth Part (can be composed of consecutive resource blocks (RBs) on the frequency axis and can correspond to one numerology (e.g., sub-carrier spacing, CP length, slot / mini-slot duration). In addition, multiple BWPs can be configured on one carrier (the number of BWPs per carrier can also be limited), but the number of activated BWPs can be limited to a part of it (e.g., 1) per carrier.)

[0077] - CORESET: COntrol REsourse SET (refers to the time-frequency resource area where PDCCH can be transmitted, and the number of CORESETs per BWP may be limited.)

[0078] - REG: Resource element group

[0079] - SFI: Slot Format Indicator (An indicator indicating the symbol level DL / UL direction within a specific slot(s), transmitted through the group common PDCCH.)

[0080] - COT: Channel occupancy time

[0081] - SPS: Semi-persistent scheduling

[0082] - QCL: Quasi-Co-Location (QCL relationship between two reference signals means that QCL parameters such as Doppler shift, Doppler spread, average delay, delay spread, and Spatial Rx parameter obtained from one reference signal can be applied to another reference signal (or antenna port(s) of the corresponding RS). In the NR system, four QCL types are defined as follows. 'typeA': {Doppler shift, Doppler spread, average delay, delay spread}, 'typeB': {Doppler shift, Doppler spread}, 'typeC': {Doppler shift, average delay}, 'typeD': {Spatial Rx parameter} For any DL RS antenna port(s), the first DL RS is set as a reference for QCL type X (X=A, B, C, or D), and additionally, the second DL RS is set as a reference for QCL type Y (Y=A, B, C, or D but X≠Y). (can be set as a reference for)

[0083] - TCI: Transmission Configuration Indication (A TCI state includes the QCL relationship between one or more DL RSs, such as DM-RS ports of the PDSCH, the DM-RS port of PDCCH, or the CSI-RS port(s) of a CSI-RS resource. For the 'Transmission Configuration Indication' field in the DCI that schedules the PDSCH, the TCI state index corresponding to each code point that constitutes the field is activated by the MAC CE, and the TCI state setting for each TCI state index is set through RRC signaling. In the Rel-16 NR system, the TCI state is set between DL RSs, but in future releases, setting between DL RS and UL RS or UL RS and UL RS may be allowed. Examples of UL RSs include SRS, PUSCH DM-RS, and PUCCH DM-RS.)

[0084] - SRI: SRS resource indicator (Indicates one of the SRS resource index values ​​set in the 'SRS resource indicator' among the fields in the DCI that schedules the PUSCH. When transmitting a PUSCH, the UE can transmit the PUSCH using the same spatial domain transmission filter used for transmitting and receiving the reference signal linked to the corresponding SRS resource. At this time, the reference RS is set by RRC signaling through the SRS-SpatialRelationInfo parameter for each SRS resource, and SS / PBCH block, CSI-RS, or SRS can be set as the reference RS.)

[0085] - TRP: Transmission and Reception Point

[0086] - TAG: Timing advance group

[0087] - PLMN: Public Land Mobile Network

[0088] Figure 1 illustrates a flexible network topology to which some examples of this specification may be applied.

[0089] To compensate for incomplete network coverage areas, a network topology that allows for more flexible and resilient split radio access networks (RANs) may be considered. For this purpose, various nodes, such as IAB nodes, relays, and RF repeaters, as illustrated in the example in Figure 1, may be applied, or NTNs may be integrated. For example, an IAB node may correspond to a node that provides wireless backhaul. For example, a relay may refer to any intermediate point, or in the case of a sidelink relay where a terminal functions as a relay, it may collectively refer to a terminal-to-network (U2N) relay and a terminal-to-terminal (U2U) relay. For example, an RF repeater may correspond to a node that simply performs the function of signal amplification and forwarding, while a network-controlled repeater may not only amplify and forward signals but also adjust transmission and reception settings based on information provided by the network. For example, an NTN node may correspond to a satellite or aircraft that provides NTN coverage that is difficult for terrestrial networks to provide. In addition to these examples, various intermediate points can be introduced to improve the network topology.

[0090] Referring to Figure 1, a split RAN can support the division of a base station into a centralized unit (CU) and one or more distributed units (DUs). The CU and DU can correspond to logical units. The CU can be further divided into a control plane (CP) portion and one or more user plane (UP) portions. Since a failure in the CU-CP affects not only the CU-UP but also the DUs, various intermediate points can be introduced to compensate for this.

[0091] An intermediate point may correspond to a terminal or a base station, depending on its relationship to other nodes. For example, an IAB node may include a mobile-termination (MT) portion and a unit (DU). The MT may connect the IAB node to a donor node. The unit (DU) of an IAB node may serve other terminals or connect to other IAB nodes to provide multi-hop wireless backhaul to the terminal. In other words, an IAB node may correspond to a base station in its relationship to a user-side node, and to a terminal in its relationship to a network-side node.

[0092] In some examples of this specification, the description of a terminal can be equally applied not only to a user-side endpoint, but also to an intermediate point corresponding to a terminal in a relative relationship with a network-side endpoint. Similarly, in some examples of this specification, the description of a base station can be equally applied not only to a network-side endpoint, but also to an intermediate point corresponding to a base station in a relative relationship with a user-side endpoint. However, in most cases where there is no additional description of the operations of three or more entities, the communicating entities in this specification are briefly described as terminals and / or base stations (or first nodes and / or second nodes), and the terms terminal and / or base stations (or first nodes and / or second nodes) are interpreted to include / replace any endpoint or any intermediate point in relation to other nodes.

[0093] That is, in some examples of this specification, for the sake of simplicity of explanation, the subjects of the operation may be referred to as a base station and / or a terminal (or a first node and / or a second node). In addition, the terms base station and / or terminal (or a first node and / or a second node) may also be interpreted / replaced as in the following examples: For example, the base station (or a first node) and the terminal (or a second node) may respectively correspond to the first endpoint and the second endpoint; may respectively correspond to the endpoint and the intermediate point; may respectively correspond to the intermediate point and the endpoint; or may respectively correspond to the first intermediate point and the second intermediate point.

[0094] In this specification, there may be zero or more intermediate points between the base station and the terminal. If intermediate points exist, they may be IAB nodes, relays, RF repeaters, NTN (non-terrestrial network) nodes, or nodes supporting other functions. An intermediate point may be a node with a fixed location or a node with an unfixed location.

[0095] Figure 2 illustrates a communication system applicable to the present disclosure.

[0096] The communication system (100) of FIG. 2 includes a wireless device (110), a network device (120), and a network (130). Here, the wireless device (110) refers to a device that performs communication using a wireless access technology (e.g., LTE, LTE-A, LTE-A pro, NR, 5G, 5G-A, 6G), and may be referred to as a communication / wireless / 5G / 6G device. Although not limited thereto, the wireless device (110) may include a robot (110a), a vehicle (110b-1, 110b-2), an XR (extended reality) device (110c), a hand-held device (110d), a home appliance (110e), an IoT (Internet of Things) device (110f), and an AI (artificial intelligence) device / server (110g). For example, the vehicle may include a vehicle equipped with a wireless communication function, an autonomous vehicle, a vehicle capable of performing vehicle-to-vehicle communication, etc. Here, the vehicle (110b-1, 110b-2) may include an unmanned aerial vehicle (UAV) (e.g., a drone). The XR device (110c) includes an augmented reality (AR) / virtual reality (VR) / mixed reality (MR) device, and may be implemented in the form of a head-mounted device (HMD), a head-up display (HUD) equipped in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance, a digital signage, a vehicle, a robot, etc. The portable device (110d) may include a smartphone, a smart pad, a wearable device (e.g., a smart watch, smart glasses), a computer (e.g., a laptop, etc.), etc. The home appliance (110e) may include a TV, a refrigerator, a washing machine, etc. The IoT device (110f) may include a sensor, a smart meter, etc. The wireless device (110) may correspond to a terminal (or first node) or an intermediate point.The network device (120) may correspond to a base station (or second node) or another intermediate point. For example, the network device (120) may also be implemented as a wireless device (110), and a specific wireless device (120a) may act as a network device (120) to another wireless device (110).

[0097] Wireless devices (110a to 110f) can be connected to a network (130) via a network device (120). AI technology can be applied to the wireless devices (110a to 110f), and the wireless devices (110a to 110f) can be connected to an AI server (110g) via a network (130). The network (130) can be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR), or a 6G network. The wireless devices (110a to 110f) can communicate with each other via the network device (120) / network (130), but can also communicate directly (e.g., sidelink communication) without going through the network device (120) / network (130). For example, vehicles (110b-1, 110b-2) can communicate directly (e.g., V2V (vehicle to vehicle) / V2X (vehicle to everything) communication). Additionally, IoT devices (110f) (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices (110a to 110f).

[0098] Wireless communication / connection (150a, 150b, 150c) can be established between wireless devices (110a to 110f) / network devices (120), network devices (120) / network devices (120). Here, the wireless communication / connection can be established through various wireless access technologies such as uplink / downlink communication (150a), sidelink communication (150b) (or D2D communication), and communication between network devices (150c) (e.g., relay, IAB (integrated access backhaul)). Through the wireless communication / connection (150a, 150b, 150c), the wireless device and the network device / wireless device, and the network device and the network device can transmit / receive wireless signals to each other. For example, the wireless communication / connection (150a, 150b, 150c) can transmit / receive signals through various physical channels. To this end, based on various descriptions of the present disclosure, at least some of various configuration information setting processes for transmitting / receiving wireless signals, various signal processing processes (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / demapping, etc.), resource allocation processes, etc. may be performed.

[0099] FIG. 3 illustrates an example of a wireless device applicable to the present disclosure.

[0100] Referring to FIG. 3, the wireless device (200) can transmit and receive wireless signals via various wireless access technologies (e.g., LTE, LTE-A, LTE-A pro, NR, 5G, 5G-A, 6G). The wireless device (200) includes at least one processor (202) and at least one memory (204), and may additionally include at least one transceiver (206) and / or at least one antenna (208).

[0101] The processor (202) controls the memory (204) and / or the transceiver (206), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (202) may process information in the memory (204) to generate first information / signal, and then transmit a wireless signal including the first information / signal via the transceiver (206). In addition, the processor (202) may receive a wireless signal including second information / signal via the transceiver (206), and then store information obtained from signal processing of the second information / signal in the memory (204). The memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, the memory (204) may store software code including instructions for performing some or all of the processes controlled by the processor (202), or for performing the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed herein. Here, the processor (202) and the memory (204) may be part of a communication modem / circuit / chip designed to implement wireless communication technology. The transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals via at least one antenna (208). The transceiver (206) may include a transmitter and / or a receiver. The transceiver (206) may be used interchangeably with an RF (radio frequency) unit. In the present disclosure, a wireless device may also mean a communication modem / circuit / chip.

[0102] Hereinafter, the hardware elements of the wireless device (200) will be described in more detail. Although not limited thereto, at least one protocol layer may be implemented by at least one processor (202). For example, at least one processor (202) may implement at least one layer (e.g., a functional layer such as physical (PHY), media access control (MAC), radio link control (RLC), packet data convergence protocol (PDCP), radio resource control (RRC), and service data adaptation protocol (SDAP)). At least one processor (202) may generate at least one Protocol Data Unit (PDU) and / or at least one Service Data Unit (SDU) according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. At least one processor (202) may generate a message, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. At least one processor (202) can generate a signal (e.g., a baseband signal) including a PDU, an SDU, a message, control information, data or information according to the functions, procedures, proposals and / or methods disclosed in this document, and provide the signal to at least one transceiver (206). At least one processor (202) can receive a signal (e.g., a baseband signal) from at least one transceiver (206) and obtain the PDU, SDU, message, control information, data or information according to the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed in this document.

[0103] At least one processor (202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. The at least one processor (202) may be implemented by hardware, firmware, software, or a combination thereof. For example, at least one application specific integrated circuit (ASIC), at least one digital signal processor (DSP), at least one digital signal processing device (DSPD), at least one programmable logic device (PLD), or at least one field programmable gate array (FPGA) may be included in the at least one processor (202). The descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. The descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document may be included in the at least one processor (202), or may be stored in at least one memory (204) and driven by the at least one processor (202). The descriptions, functions, procedures, suggestions, methods and / or flowcharts disclosed in this document may be implemented using firmware or software in the form of code, instructions and / or sets of instructions.

[0104] At least one memory (204) can be connected to at least one processor (202) and can store various forms of data, signals, messages, information, programs, codes, instructions and / or commands. The at least one memory (204) can be configured as a read only memory (ROM), a random access memory (RAM), an erasable programmable read only memory (EPROM), a flash memory, a hard drive, a register, a cache memory, a computer readable storage medium and / or a combination thereof. The at least one memory (204) can be located internally and / or externally to the at least one processor (202). In addition, the at least one memory (204) can be connected to the at least one processor (202) via various technologies such as a wired or wireless connection.

[0105] At least one transceiver (206) can transmit user data, control information, wireless signals / channels, etc., mentioned in the methods and / or flowcharts of this document to at least one other device. At least one transceiver (206) can receive user data, control information, wireless signals / channels, etc. mentioned in the descriptions, functions, procedures, proposals, methods and / or flowcharts disclosed in this document from at least one other device. For example, at least one transceiver (206) can be connected to at least one processor (202) and can transmit and receive wireless signals. For example, at least one processor (202) can control at least one transceiver (206) to transmit user data, control information, or wireless signals to at least one other device. Furthermore, at least one processor (202) can control at least one transceiver (206) to receive user data, control information, or wireless signals from at least one other device. In addition, at least one transceiver (206) may be connected to at least one antenna (208), and at least one transceiver (206) may be configured to transmit and receive user data, control information, wireless signals / channels, etc. mentioned in the descriptions, functions, procedures, proposals, methods and / or operation flowcharts disclosed in this document through at least one antenna (208). In this document, at least one antenna may be a plurality of physical antennas or a plurality of logical antennas (e.g., antenna ports). At least one transceiver (206) may convert the received wireless signals / channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, wireless signals / channels, etc. using at least one processor (202). At least one transceiver (206) may convert the processed user data, control information, wireless signals / channels, etc. from baseband signals to RF band signals using at least one processor (202).For this purpose, at least one transceiver (206) may include an (analog) oscillator and / or filter.

[0106] The components of the wireless device described with reference to FIG. 3 may be referred to by different terms in terms of functionality. For example, the processor (202) may be referred to as a control unit, the transceiver (206) as a communication unit, and the memory (204) as a storage unit. In some cases, the communication unit may be used to mean at least a portion of the processor (202) and the transceiver (206).

[0107] The structure of the wireless device described with reference to FIG. 3 can be understood as the structure of at least a portion of various devices. For example, the structure of the wireless device illustrated in FIG. 3 can be at least a portion of various devices described with reference to FIG. 2 (e.g., a robot (110a), a vehicle (110b-1, 110b-2), an XR device (110c), a portable device (110d), a home appliance (110e), an IoT device (110f), an AI device / server (110g)). Furthermore, according to various embodiments, in addition to the components illustrated in FIG. 3, the device may further include other components.

[0108] For example, the device may be a portable device such as a smartphone, a smart pad, a wearable device (e.g., a smart watch, smart glasses), or a portable computer (e.g., a laptop, etc.). In this case, the device may further include at least one of a power supply unit that supplies power and includes a wired / wireless charging circuit, a battery, etc., an interface unit that includes at least one port for connection with another device (e.g., an audio input / output port, a video input / output port), and an input / output unit for inputting and outputting image information / signals, audio information / signals, data, and / or information input from a user.

[0109] For example, the device may be a mobile device such as a mobile robot, a vehicle, a train, an aerial vehicle (AV), a ship, etc. In this case, the device may further include at least one of a driving unit including at least one of an engine, a motor, a power train, wheels, brakes, and a steering unit of the device, a power supply unit including a wired / wireless charging circuit, a battery, etc. that supplies power, a sensor unit that senses status information, environmental information, and user information of the device or its surroundings, an autonomous driving unit that performs functions such as path maintenance, speed control, and destination setting, and a position measurement unit that obtains location information of the mobile device through a global positioning system (GPS) and various sensors.

[0110] For example, the device may be an XR device such as an HMD, a head-up display (HUD) installed in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance, a digital signage, a vehicle, a robot, etc. In this case, the device may further include at least one of a power supply unit that supplies power and includes a wired / wireless charging circuit, a battery, etc., an input / output unit that obtains control information, data, etc. from the outside and outputs the generated XR object, and a sensor unit that senses status information, environmental information, and user information of the device or the surroundings of the device.

[0111] For example, the device may be a robot that can be classified into industrial, medical, household, military, etc. types depending on the purpose or field of use. In this case, the device may further include at least one of a sensor unit that senses status information, environmental information, and user information of the device or its surroundings, and a driving unit that performs various physical actions, such as moving the robot joints.

[0112] For example, the device may be an AI device such as a TV, a projector, a smartphone, a PC, a laptop, a digital broadcasting terminal, a tablet PC, a wearable device, a set-top box (STB), a radio, a washing machine, a refrigerator, digital signage, a robot, a vehicle, etc. In this case, the device may further include at least one of an input unit that acquires various types of data from the outside, an output unit that generates output related to sight, hearing, or touch, a sensor unit that senses status information, environmental information, and user information of the device or its surroundings, and a training unit that trains a model composed of an artificial neural network using learning data.

[0113] The structure of the wireless device illustrated in FIG. 3 may be understood as a part of a terminal (or first node), or as a part of an intermediate point, or as a part of a base station (or second node). If the device illustrated in FIG. 3 is a base station (or second node), the device may further include a wired transceiver for front haul and / or back haul communications. However, if the front haul and / or back haul communications are based on wireless communications, at least one transceiver (206) illustrated in FIG. 3 may be used for front haul and / or back haul communications, and a wired transceiver may not be included.

[0114] FIG. 4 illustrates a communication procedure between a first node (e.g., a terminal) and a second node (e.g., a base station) applicable to the present disclosure.

[0115] The second node of FIG. 4 supports dynamic spectrum sharing (DSS), which can provide connectivity to both nodes implementing 6G technology and nodes implementing pre-6G wireless communication technologies (e.g., 5G, 4G). That is, the first node of FIG. 4 can implement either 6G technology or pre-6G wireless communication technologies (e.g., 5G, 4G). Furthermore, the first node and / or the second node can support full duplex mode as well as non-overlapping full duplex mode.

[0116] In Fig. 4, for the sake of simplicity of explanation, the first node and the second node are assumed to be a terminal and a base station, respectively, and operations of the terminal (110) and the base station (120) transmitting and / or receiving data and operations performed prior thereto are illustrated. However, the operations of Fig. 4 are not limited to operations between the terminal and the base station, and may be interpreted as operations between the first node and the second node. In addition, although Fig. 4 illustrates direct wireless signal transmission and reception operations between the terminal (110) and the base station (120), one or more intermediate points may exist between the terminal (110) and the base station (120), and wireless signals may be transmitted and received via one or more intermediate points.

[0117] Referring to FIG. 4, the terminal (110) and the base station (120) can perform synchronization (401). For example, the terminal (110) performs an initial cell search operation. Specifically, the terminal (110) can detect a synchronization signal for connection to at least one base station transmitted from the base station (120) according to a predefined rule. Here, the synchronization signal can include a plurality of synchronization signals classified according to structure or purpose (e.g., a first synchronization signal (e.g., a primary synchronization signal), a second synchronization signal (e.g., a secondary synchronization signal), etc.). Through this, the terminal (110) can confirm the boundary of a unit (e.g., a frame, a subframe, a slot, and / or a symbol) constituting a wireless signal transmission of the base station (120) and obtain information (e.g., a cell identifier) ​​about the base station (120).

[0118] The terminal (110) can obtain system information transmitted from the base station (120) (403). The system information is information related to the properties, characteristics, and / or capabilities of the base station (120) required to access the base station (120) and use the service, and can be classified according to the content (e.g., whether it is essential for access), transmission structure (e.g., channel used, whether provided on-demand), etc., and can be classified into, for example, first system information (e.g., master information block (MIB), primary system information), second system information (e.g., system information block (SIB), secondary system information), etc. If necessary, the terminal (110) can transmit a signal requesting system information before receiving the system information. However, the request and provision of system information can be performed after the random access procedure described below.

[0119] The terminal (110) and the base station (120) can perform a random access procedure (405). The terminal (110) can transmit and / or receive at least one message (e.g., a random access preamble, a random access response (RAR) message, etc.) for the random access procedure based on information related to a channel for the random access procedure of the base station (120) obtained through system information (e.g., channel location, channel structure, structure of a supported preamble, etc.). For example, the terminal (110) can transmit a first message (e.g., a preamble, MSG1) through the channel for the random access procedure, receive a second message (e.g., an RAR message, MSG2), transmit a third message (e.g., MSG3) including information related to the terminal (110) (e.g., identification information) to the base station (120) using scheduling information included in the second message, and receive a fourth message (e.g., MSG4) for contention resolution and / or connection establishment. As another example, the first and third messages may be sent and received as one message, or the second and fourth messages may be sent and received as one message.

[0120] The terminal (110) and the base station (120) can perform signaling of control information (407). Here, the control information can be defined in various layers, such as a layer that controls a connection (e.g., a radio resource control (RRC) layer), a layer that handles mapping between logical channels and transport channels (e.g., a media access control (MAC) layer), and a layer that handles physical channels (e.g., a physical (PHY) layer). For example, the terminal (110) and the base station (120) can perform at least one of signaling for establishing a connection, signaling for determining settings related to communication, and signaling for indicating allocated resources.

[0121] The terminal (110) and the base station (120) can transmit and / or receive data (409). In other words, the terminal (110) and the base station (120) can process, transmit, and / or receive data based on signaling of control information. For example, when transmitting data, the terminal (110) or the base station (120) can perform at least one of channel encoding, rate matching, scrambling, constellation mapping, layer mapping, waveform modulation, antenna mapping, and resource mapping on the information bits. Conversely, when receiving data, the terminal (110) or the base station (120) can perform at least one of signal extraction from resources, waveform demodulation for each antenna, signal arrangement considering layer mapping, constellation demapping, descrambling, and channel decoding.

[0122] <6G System Core Technologies>

[0123] The 6G (wireless) system aims to provide (i) very high data rates per device, (ii) a very large number of connected devices, (iii) global connectivity, (iv) very low latency, (v) low energy consumption for battery-free Internet of Things (IoT) devices, (vi) ultra-reliable connectivity, and (vii) connected intelligence with machine learning capabilities. The vision of the 6G system can be divided into four aspects: intelligent connectivity, deep connectivity, holographic connectivity, and ubiquitous connectivity.

[0124] As core implementation technologies of the 6G system, technologies such as artificial intelligence (AI), THz (terahertz) communication, optical wireless technology, FSO backhaul network, massive MIMO technology, blockchain, 3D networking, quantum communication, unmanned aerial vehicles, cell-free communication, wireless information and energy transfer (WIET), integration of sensing and communication, integration of access backhaul networks, holographic beamforming, big data analysis, and large intelligent surface (LIS) can be adopted.

[0125] artificial intelligence

[0126] Incorporating AI into communications can streamline and improve real-time data transmission. AI can use numerous analytics to determine how complex target tasks should be performed. This means AI can increase efficiency and reduce processing delays. Time-consuming tasks such as handovers, network selection, and resource scheduling can be performed instantly using AI. AI can also play a crucial role in machine-to-machine (M2M), machine-to-human, and human-to-machine communications. Furthermore, AI can facilitate rapid communication in brain-computer interfaces (BCIs). AI-based communication systems can be supported by metamaterials, intelligent structures, intelligent networks, intelligent devices, intelligent cognitive radios, self-sustaining wireless networks, and machine learning.

[0127] The following describes a functional framework for AI / ML operations.

[0128] Below, to explain AI (or AI / ML) more specifically, the terms can be defined as follows.

[0129] - Data collection: Data collected from network nodes, management entities, or terminals as a basis for AI model training, data analysis, and inference.

[0130] - AI Model: A data-driven algorithm that applies AI technology to generate a set of outputs containing predictive information and / or decision parameters based on a set of inputs.

[0131] - AI / ML Training: An online or offline process of training an AI model by learning features and patterns that best represent the data and obtain a trained AI / ML model for inference.

[0132] - AI / ML Inference: The process of making predictions or inducing decisions based on collected data and the AI ​​model using a trained AI model.

[0133] Life Cycle Management (LCM) procedures for AI / ML models (i.e., model training, model deployment, model inference, model monitoring, model updates, etc.) can be divided into functionality-based LCM and model-based LCM. In functionality-based LCM, AI / ML models may not be identified by the network, and the network can direct the activation / deactivation / fallback / switching of AI / ML functionality. In model-ID (identifier)-based LCM, AI / ML models can be identified by the network, and the network / terminal can activate / deactivate / select / switch AI / ML models based on the model ID.

[0134] Figure 5 illustrates a general functional architecture for an AI / ML model.

[0135] In particular, Figure 5 illustrates a general functional architecture relevant to both Functionality-based LCM and Model-based LCM. Some of the functions or some of the data / information / command flows (i.e., arrows) illustrated in Figure 5 may be omitted.

[0136] Referring to FIG. 5, a general functional framework can be configured to include a data collection function (10), a model training function (20), a management function (30), an inference function (40), and a model storage function (50).

[0137] The Data Collection function (10) is a function that provides input data to the Model Training function (20), Management function (30), and Inference function (40). The Data Collection function (10) can perform data preparation based on raw data and provide input data processed through data preparation. Examples of raw data may include received data / measurement data from terminals or other network entities, inference / output of AI / ML models, etc. The Data Collection function (10) may be performed by a single entity (e.g., terminal, network node, etc.) or may be performed by multiple entities.

[0138] Here, training data (11) refers to data required as input for the AI / ML Model Training function (20). Monitoring data (12) refers to data required as input for the Management (30) of the AI / ML model or AI / ML function. Inference data (13) refers to data required as input for the AI / ML Inference function (30).

[0139] The Model Training function (20) is a function that performs AI / ML model training, validation, and testing, which can generate model performance metrics that can be used as part of the AI / ML model testing procedure. The Model Training function (20) can perform data preparation (e.g., data pre-processing and cleaning, forming, and transformation) based on the Training Data (11) transferred from the Data Collection function (10), if necessary.

[0140] Trained / Updated Model (21): If there is a Model Storage function (50), it is used to pass a trained, validated and tested AI / ML model to the Model Storage function (50) or to pass an updated version of the model to the Model Storage function (50).

[0141] The Management function (30) is a function that supervises the operation of the AI / ML model or AI / ML function. In addition, the Management function (30) may perform decisions to ensure appropriate inference operations based on data received from the Data Collection function (10) (i.e., Monitoring Data (12)) and / or data received from the Inference function (40) (i.e., Inference Output (41)).

[0142] Management Instruction (32) is information required as input to manage the Inference function (40). The relevant information may include selection / (de)activation / switching of an AI / ML model or AI / ML-based function, and may also include fallback to non-AI / ML operations (i.e., not relying on the inference process).

[0143] A Model Transfer / Delivery Request (33) can be used to request model(s) from Model Storage (50).

[0144] A Performance Feedback / Retraining Request (31) refers to information required as input to the Model Training function (20) (e.g., for the purpose of (re)training or updating the model).

[0145] The Inference function (40) is a function that provides output from the process of applying an AI / ML model or AI / ML function using data (i.e., Inference Data (13)) provided by Data Collection (10) as input. Data preparation (e.g., data preprocessing and cleaning, formatting, and transformation) may also be performed based on the Inference Data (13) delivered by Data Collection (10). If necessary, the Inference function (40) may also perform data preparation (e.g., data preprocessing and cleaning, forming, and transformation) based on the Inference Data (13) provided by Data Collection function (10).

[0146] Inference Output (41) is data used in the Management function (30) to monitor the performance of an AI / ML model or AI / ML function. Inference Output (41) may include the inference output of the AI / ML model generated by the Inference function (30), and the details of the inference output may vary depending on the use case.

[0147] The Model Storage function (50) stores a learned / updated model that can be used to perform the Inference function (40). The Model Storage function (50) illustrated in FIG. 5 can be used as a reference point (if any) when applicable to protocol termination, model transmission / delivery, and related processes. Furthermore, the Model Storage function (50) is merely an example and is not intended to limit the storage location of actual AI / ML models, and may be omitted.

[0148] Model Transfer / Delivery (51) is used to transfer AI / ML models to inference functions.

[0149] The level of cooperation can be defined as follows depending on the capability of AI / ML functions between multiple nodes, and variations due to combination of multiple levels or separation of any one level are also possible.

[0150] Cat 0a) No collaboration framework: AI / ML algorithms are purely implementation-based and do not require any changes to the wireless interface.

[0151] Cat 0b) This level corresponds to a framework with a modified wireless interface tailored to efficient implementation-based AI / ML algorithms, but without collaboration.

[0152] Category 1) involves inter-node support to improve the AI / ML algorithms of each node. For example, this applies when a specific node receives support from another node (for training, adaptation, etc.) and vice versa. At this level, model exchange between network nodes is not required.

[0153] Category 2) Joint AI / ML tasks can be performed across multiple nodes. This level requires the exchange of AI / ML model commands or network nodes.

[0154] FIG. 5 is a diagram illustrating an overall functional framework for an AI / ML model, and not all functions and / or all data / information / command signals illustrated in FIG. 5 may be performed within a specific node, but only some of them may be performed.

[0155] AI / ML models can be divided into one-side models and two-side models depending on whether training and / or inference are performed on a single node or jointly / sequentially on multiple nodes.

[0156] A one-side model can refer to an AI / ML model in which inference is performed entirely by a single node (e.g., a terminal or network). Here, AI / ML model training can also be performed entirely by a single node. AI / ML model training and inference can be performed by the same node, or they can be performed by separate nodes.

[0157] A two-side model can refer to an AI / ML model in which joint inference is performed across multiple nodes (e.g., terminals and networks). Joint inference refers to inference being performed jointly across multiple nodes. For example, the first part of the inference may be performed by a first node, and the remaining part by a second node. Two-side models can be categorized into several types depending on the training method of the AI / ML model, as follows:

[0158] - First type: AI / ML models can be trained on a single node. In this case, joint training can be performed. The trained model can then be distributed to other nodes / objects.

[0159] - Second type: Joint training of AI / ML models can be performed on multiple nodes / entities (e.g., networks and terminals). Joint training can mean that model generation (e.g., CSI generation part) and model reconstruction (CSI compression by sub-use case) are trained in the same loop for forward activation and backward gradient. In this type, joint training can include both simultaneous training (i.e., model generation training and model reconstruction training are performed simultaneously) and sequential training (i.e., model reconstruction training is performed after model generation training).

[0160] - Third type: Separate training of AI / ML models can be performed on multiple nodes (e.g., networks and terminals). Separate training may mean that training begins sequentially on one node and continues on other nodes. In this case, the first node first performs the AI / ML model and shares the training data with the second node. The second node can then use the shared training data to perform the AI / ML model. For example, training for the CSI generation part may be performed by the terminal, while CSI reconstruction may be performed by the network.

[0161] Figure 6 illustrates a communication procedure between a first node (e.g., terminal) and a second node (e.g., base station) to which an AI / ML model is applied.

[0162] The operations described below can be described / interpreted based on the AI / ML model proposed in this specification, as shown in Fig. 6 below, even without separate mention (i.e., without explicit mention of being by / based on / for the AI / ML model). In addition, unless specifically limited, the AI / ML model can correspond to a one-side model in which inference is entirely performed by a single node, or a two-side model in which joint inference is performed by multiple nodes.

[0163] First signaling (601): In the description below, the signaling (e.g., information / data / channel / signal, etc.) or set of signaling between a specific node (e.g., terminal, network, etc.) and another node may be interpreted as the signaling or set of signaling of the first signaling (601) used to perform an operation based on an AI / ML model, even if not otherwise mentioned. For example, it may correspond to training data for training (i.e., generation and / or reconstruction) the AI / ML model of FIG. 5, or correspond to inference data used for inference of the AI / ML model, or correspond to feedback for the AI / ML model, etc. If signaling between nodes is not required prior to an operation based on an AI / ML model in the present specification, the first signaling (601) may be omitted. If a one-side model is used in the present specification, the one-way / two-way signaling (set) in the present specification may correspond to the signaling of the first signaling (601). In addition, when a two-side model is used in this specification, the one-way / two-way signaling in this specification may correspond to the first signaling (601), and also, a repetitive signaling operation may correspond to the first signaling (601).

[0164] For example, in AI / ML model-based beam management (BM), if a base station predicts (i.e., infers) beam(s) with good quality based on an AI / ML model, the base station can receive quality / intensity information for multiple beams from a terminal. Furthermore, if a terminal predicts (i.e., infers) beam(s) with good quality based on an AI / ML model, the terminal can receive multiple beams from the base station.

[0165] AI / ML model-based operation (602): In the description below, an operation (e.g., calculation, selection, prediction, etc.) in a specific node (e.g., terminal, network, etc.) or a joint operation (e.g., calculation, selection, prediction, etc.) in multiple nodes (e.g., terminal, network, etc.) may correspond to an AI / ML model-based operation (602) based on one or more functions in the functional framework of the AI / ML model, even if not mentioned separately. For example, it may correspond to training (i.e., generation and / or reconstruction) of the AI / ML model of FIG. 5 or inference of the AI / ML model, etc. When a one-side model is used, an operation performed by a single node in the present specification may correspond to an AI / ML model-based operation (602), and also, when a two-side model is used, a joint operation performed by multiple nodes in the present specification may correspond to an AI / ML model-based operation (602).

[0166] For example, in an AI / ML model-based BM, the base station can use quality / intensity information for multiple beams received from the terminal as inference data to predict (i.e., infer) beam(s) with good quality based on the AI / ML model. Furthermore, the terminal can measure multiple beams received from the base station and use the measurement results as inference data to predict (i.e., infer) beam(s) with good quality based on the AI / ML model.

[0167] Second signaling (603): In the description below, signaling (e.g., information / data / channel / signal, etc.) or a set of signaling between a specific node (e.g., terminal, network, etc.) and another node may be interpreted as a second signaling (603) or a set of signaling generated due to (as a result of) an operation based on an AI / ML model, even if not otherwise mentioned. For example, it may correspond to an output resulting from inference of the AI / ML model in FIG. 5. If signaling between nodes is not required as a result of an operation based on an AI / ML model in this specification, the second signaling (603) may be omitted. If a one-side model is used in this specification, a one-way / two-way signaling (set) in this specification may correspond to the second signaling (603). In addition, when a two-side model is used in this specification, the one-way / two-way signaling in this specification may correspond to the second signaling (603), and also, a repetitive signaling operation may correspond to the second signaling (603).

[0168] For example, in an AI / ML model-based BM, the base station can transmit to the terminal the beam(s) predicted based on the AI / ML model as candidates so that the terminal can determine the optimal beam. Furthermore, the terminal can report to the base station the beam(s) predicted based on the AI / ML model to request the base station to transmit the candidate beams as candidates for determining the optimal beam.

[0169] THz communication (terahertz communication)

[0170] Data rates can be increased by increasing bandwidth. This can be achieved by utilizing sub-THz communications with wide bandwidths and applying advanced massive MIMO technology. THz waves, also known as sub-millimeter waves, typically refer to the frequency range between 0.1 THz and 10 THz, with corresponding wavelengths ranging from 0.03 mm to 3 mm. The 100 GHz to 300 GHz band (sub-THz band) is considered a key part of the THz spectrum for cellular communications. Adding the sub-THz band to the mmWave band will increase the capacity of 6G cellular communications. Among the defined THz bands, 300 GHz to 3 THz lies in the far infrared (IR) frequency band. While part of the optical band, the 300 GHz to 3 THz band lies at the boundary of the optical band, immediately following the RF band. Therefore, this 300 GHz to 3 THz band exhibits similarities to RF.

[0171] Figure 7 illustrates the electromagnetic spectrum according to one embodiment of the present disclosure. The embodiment of Figure 7 can be combined with various embodiments of the present disclosure. Key characteristics of THz communications include (i) a widely available bandwidth to support very high data rates, and (ii) high path loss at high frequencies (highly directional antennas are essential). The narrow beamwidth generated by the highly directional antenna reduces interference. The small wavelength of THz signals allows for a much larger number of antenna elements to be integrated into devices and base stations operating in this band. This enables the use of advanced adaptive array techniques to overcome range limitations.

[0172] Transmitting system information (i.e., information related to the properties, characteristics, and / or capabilities of a BS required to use a service, such as MIB, SIB, etc.) in the THz frequency band may be inefficient because, as the beam width becomes narrower in high frequency bands, more beam sweeps must be performed to cover the entire area of ​​the cell. In particular, transmitting system information in this manner is even more inefficient when there are not many users in the cell. Accordingly, a system information transmission procedure such as that illustrated in FIG. 8 may be used.

[0173] Figure 8 illustrates an example of a procedure for transmitting system information for THz communications to which the present disclosure applies. While this example was developed with THz in mind, it is also applicable to 6G communication environments where THz is not applicable. Furthermore, the procedure illustrated in Figure 8 can be combined with various embodiments of the present disclosure described below. For example, the embodiments described below can be performed based on system information acquired through the procedure illustrated in Figure 8.

[0174] Referring to FIG. 8, the base station can transmit system information of cell #1 through cell #2 (801). That is, the base station provides at least two cells, cell #1 uses a THz frequency band, and cell #2 uses a non-THz frequency band. Here, the system information can include at least one information / state / parameter / setting generated in each of a higher layer and a physical layer. For example, the at least one information / state / parameter / setting generated in the higher layer can include at least one of an SFN, control information setting for SIB1 (e.g., PDCCH configuration for SIB1, etc.), information related to cell selection / entry (e.g., cell barring, cell re-selection, etc.), and subcarrier spacing, and the at least one information / state / parameter / setting generated in the physical layer can include at least one of an SFN, a half frame indicator, and an SSB index. However, this is merely an example, and system information may include information / status / parameters / settings related to Cell #1 / Cell #2 generated from various types of physical layers / upper layers. For this purpose, as an example, Cell #1 and Cell #2 may have a relationship as a secondary cell and a primary cell.

[0175] The UE can acquire synchronization for cell #1 (803). Synchronization can be acquired by detecting a synchronization signal. Typically, synchronization is acquired before receiving system information. However, since the system information for cell #1 is received from cell #2, synchronization acquisition for cell #1 can be performed after receiving the system information. For example, the UE can acquire synchronization based on the system information. However, unlike FIG. 8, in another example, synchronization acquisition can be performed before step 801.

[0176] The UE may transmit a signal for accessing cell #1 (805). For example, the signal may include information for accessing cell #1 (e.g., a random access preamble). The structure of the signal and the resources for transmitting the signal (e.g., a channel) may be identified through system information. Thereafter, the UE and the base station may perform an access procedure for cell #1 and communicate (807). During this process, operations according to various embodiments described below may be performed.

[0177] The procedure described with reference to FIG. 8 may be performed when UE (801) first accesses cell #1 of the base station. Alternatively, a similar procedure may be performed when UE (801) hands over to cell #1 of the base station. However, in the case of handover, the system information of cell #1 may be received from a cell of a base station other than cell #2 of the base station.

[0178] Communications in the THz band are expected to experience extremely severe path loss, and to overcome this, terminals and base stations must use extremely sharp beams. The use of sharp beams means that terminals and base stations must perform beam control in addition to beamforming, and the number of beams used increases significantly. Consequently, it takes a very long time to align the transmit and receive beams between the base station and terminals. Furthermore, if the beam alignment between the base station and terminals is misaligned due to the movement or movement of the terminals, frequent re-alignment of the beams is required, which can lead to link instability. Accordingly, a beam management procedure, as illustrated in FIG. 9 below, may be employed.

[0179] FIG. 9 illustrates a beam management procedure applicable to the present disclosure. FIG. 9 illustrates an example of a procedure for searching and / or selecting beams for THz communication, but is not limited to a THz environment, and the present disclosure is applicable to a 6G communication environment. In addition, the procedure illustrated in FIG. 9 can be combined with various embodiments of the present disclosure described below. Here, a beam may be interpreted as 'spatial (setting) information', 'spatial domain filter', 'spatial domain transmission filter', 'spatial domain reception filter', or / and a term having an equivalent technical meaning that can distinguish the beam (e.g., Reference signal, SSB (Synchronization Signal Block) Index, TRP (transmission reception point), panel, cell, TP (transmission point), base station, control resource related information (e.g., CORESET (control resource set) related information, etc.).

[0180] Referring to FIG. 9, a base station can configure resources for beam management (901). Here, the resources can include at least one of time-frequency resources, channels, and spatial resources (e.g., antenna ports). For example, the base station can utilize a beam search signal (BSS) that is transmitted spatially separated from existing downlink signals / channels for beam search. Here, the BSS can be transmitted based on a dedicated port for beam search. The dedicated port can be a different port from a port for transmitting existing downlink signals / channels (e.g., synchronization signals (e.g., SSB, etc.), data channels (e.g., PDSCH, etc.)). BSS is a term defined for convenience of explanation, and the technical concept according to the present embodiment is not limited to the term BSS itself. That is, a signal transmitted based on a dedicated port defined / configured for beam search can be included in the technical concept according to the present embodiment.

[0181] The base station can transmit measurement signals using multiple transmission beams (903). For example, the measurement signals can include at least one of a reference signal and a synchronization signal. At this time, the measurement signals can be transmitted as many times as the number of beams that require measurement, and can be transmitted using a multi-beam transmission method that forms multiple beams simultaneously to reduce sweeping time. Here, the multi-beam transmission can be performed based on at least one of a multi-panel, a sub-array, and a true time delay (TTD).

[0182] The UE may transmit a feedback signal to the base station (905). The feedback signal indicates at least one beam selected by the UE. The UE may select at least one preferred beam based on the received measurement signals. The UE and the base station may communicate (907). At this time, the UE and the base station may communicate using the previously selected beam. If channel reciprocity is established, the transmission beam of the UE may also be determined through operations 903 and 905, and thus the transmission of the UE may also be performed using the beam selected in operation 905. If channel reciprocity is not established, a procedure including transmission of measurement signals by the UE and transmission of a feedback signal by the base station may be performed first to determine the transmission beam of the UE. In operation 907, operations according to various embodiments described below may be performed.

[0183] Integrated Sensing and Communication (ISAC)

[0184] Wireless sensing is a technology that uses radio frequencies to determine the instantaneous linear velocity, angle, distance (range), etc. of an object, thereby obtaining information about the characteristics of the environment and / or objects within the environment. Because radio frequency sensing does not require a networked device to connect to the object, it can provide a service for object positioning without a device. The ability to obtain range, velocity, and angle information from radio frequency signals can enable a wide range of new capabilities, such as various object detection, object recognition (e.g., vehicles, humans, animals, UAVs), and high-precision localization, tracking, and activity recognition. Wireless sensing services can provide information to a variety of industries (e.g., drones, smart homes, V2X, factories, railways, public safety, etc.), enabling applications such as intruder detection, assisted vehicle steering and navigation, trajectory tracking, collision avoidance, traffic management, and health and traffic management. In some cases, wireless sensing can utilize non-3GPP type sensors (e.g., radar, cameras) to further support 3GPP-based sensing. For example, the operation of wireless sensing services, i.e., sensing operations, may depend on the transmission, reflection, and scattering of wireless sensing signals. Therefore, wireless sensing offers an opportunity to enhance existing communication systems from a communication network to a wireless communication and sensing network.

[0185] FIG. 10 illustrates an example of a sensing operation according to an embodiment of the present disclosure. The embodiment of FIG. 10 can be combined with various embodiments of the present disclosure. Specifically, FIG. 10(a) illustrates an example of sensing using a sensing receiver and a sensing transmitter located at the same location (e.g., monostatic sensing), and FIG. 10(b) illustrates an example of sensing using a separated sensing receiver and sensing transmitter (e.g., bistatic sensing).

[0186] For example, in a wireless communication system based on a 6G network of the present specification, referring to FIG. 10(a), the sensing transmitter and the sensing receiver may be configured to be included in a single base station (i.e., the same base station) or a single terminal (i.e., the same terminal). Alternatively, referring to FIG. 10(b), the sensing transmitter and the sensing receiver may be configured to be included in different base stations, different terminals, or each terminal and base station.

[0187] In this regard, the following six types of sensing modes can be defined based on whether the sensing transmitter and sensing receiver are included in the base station or the terminal, respectively.

[0188] - Mode 1: A mode in which the sensing transmitter and sensing receiver are contained in a single base station (e.g., base station-based sensing mode in monostatic mode).

[0189] - Second mode: A mode in which the sensing transmitter is included in a first base station and the sensing receiver is included in a second base station different from the first base station (e.g., base station-based sensing mode in bistatic mode).

[0190] - Mode 3: A mode in which the sensing transmitter is included in the base station and the sensing receiver is included in the terminal (e.g., base station-terminal sensing mode).

[0191] - Mode 4: A mode in which the sensing transmitter is included in the terminal and the sensing receiver is included in the base station (e.g., terminal-base station sensing mode).

[0192] - Mode 5: A mode in which the sensing transmitter and sensing receiver are contained in a single terminal (e.g., terminal-based sensing mode in monostatic mode).

[0193] - 6th mode: A mode in which the sensing transmitter is included in a first terminal and the sensing receiver is included in a second terminal different from the first terminal (e.g., terminal-based sensing mode in bistatic mode).

[0194] In a wireless communication system based on a 6G network of the present specification, one or more of the six types of sensing modes described above may be utilized independently / in combination.

[0195] In relation to the sensing operation in FIG. 10, the sensing transmitter may transmit a sensing signal for sensing one or more objects (and / or an environment around the objects). For example, the sensing signal may correspond to a radio (frequency) signal defined to be transmittable by a base station / terminal in a wireless communication system based on a 6G network of the present specification. The sensing receiver may receive a signal scattered / reflected by one or more objects (and / or an environment around the objects) from a sensing signal transmitted from the sensing transmitter. In the sensing receiver, sensing data may be derived from the scattered / reflected signals, and sensing results may be generated / obtained through processing of the sensing data. Here, the sensing results may include characteristic information (e.g., location, distance, speed, angle, etc.) about one or more objects (and / or the environment around the objects). The sensing results generated / obtained in this way may be utilized for wireless sensing services (e.g., detection, tracking, etc. of objects and / or environments) provided in the wireless communication system based on the 6G network of the present specification, or may be provided / disclosed to a trusted third party.

[0196] Additionally, the sensing operation in FIG. 10 is described as a representative example of the operation in a wireless communication system based on a 6G network, but can be extended and applied to cases where terminals / base stations / signals based on networks of previous generations (e.g., 4G, 5G, etc.) are utilized.

[0197] Additionally, with respect to the wireless sensing described herein, in a wireless communication system based on a 6G network of the present specification, time / frequency resources for sensing operations and time / frequency resources for general communications (e.g., UL / DL / sidelink-based communications, etc.) may be scheduled / configured separately.

[0198] FIG. 11 illustrates time / frequency resources for sensing operations according to one embodiment of the present disclosure. The embodiment of FIG. 11 may be combined with various embodiments of the present disclosure.

[0199] Referring to FIG. 11, time / frequency resources (hereinafter, sensing resources) for the aforementioned sensing operation (e.g., sensing operation based on FIG. 10) can be set / allocated separately from time / frequency resources (hereinafter, communication resources) for general communication.

[0200] For example, as illustrated in FIG. 11, sensing resources can be set / allocated in units of symbols in the time domain and / or resource blocks in the frequency domain. Resources other than those for which the sensing resources are set / allocated can be utilized as resources for general communication. That is, sensing resources and communication resources can be set / allocated based on a time-division multiplexing (TDM) scheme and / or a frequency-division multiplexing (FDM) scheme in terms of the operation of the base station / terminal. Additionally or alternatively, unlike what is illustrated in FIG. 10, sensing resources can also be set / allocated based on other units in the time domain (e.g., slots, frames, absolute time (ms, us), etc.) and / or other units in the frequency domain (e.g., subcarriers, carriers, absolute frequencies (MHz, GHz), etc.).

[0201] Additionally or alternatively, in connection with the setting / allocation / scheduling of resources for general communication as described herein, the relationship between the resources and the aforementioned sensing resources may need to be considered. For example, when setting / allocating resources for general communication according to the embodiment(s) of the present disclosure, the resources may be set / allocated to rate-match or puncture the resource region corresponding to the sensing resource. For example, when scheduling resources for general communication according to the embodiment(s) of the present disclosure, the resources may be scheduled so as not to overlap with the resource region corresponding to the sensing resource. If the resources for general communication according to the embodiment(s) of the present disclosure and the resource region corresponding to the sensing resource are set / allocated / scheduled to overlap, one or both operations may be dropped, skipped, or postponed based on priorities, predefined rules, etc. That is, in the embodiment(s) of the present specification, it may be desirable that resources related to general communication (e.g., resources for signals / channels related to UL / DL / Sidelink-based data / control, etc.) are set / allocated / scheduled so as not to overlap with the sensing resources described above.

[0202] Additionally, various channel modeling methods may be applied in connection with the wireless sensing described herein. Channel modeling related to sensing may refer to configuring a path for transmitting and receiving sensing signals and / or scattered / reflected signals, taking into account the object being sensed and / or the environment in which the object resides. Channel modeling may be related to the performance / requirements of sensing in wireless communication systems, and thus may be an important factor in validating the sensing function.

[0203] Channels related to sensing can be divided into channels between objects (e.g., targets of interest) and sensing transmitters / receivers, and channels between the environment to which the object belongs and sensing transmitters / receivers. In this regard, channel modeling related to sensing can be divided based on sensing mode (e.g., the six types of modes described above), whether there is an object / environment, and / or sensing scenarios. For example, channel modeling for a target in a base station / terminal-based monostatic sensing mode, channel modeling for a target in a base station / terminal-based bistatic sensing mode, channel modeling for the environment in a base station / terminal-based monostatic sensing mode, and channel modeling for the environment in a base station / terminal-based bistatic sensing mode can be configured and optimized differently. For example, when various sensing scenarios are classified, channel modeling for detection, location, and tracking scenarios, channel modeling for motion recognition, and channel modeling for imaging / environment reconstruction scenarios can be divided, etc. Additionally, channel modeling related to sensing may be based on statistical channel modeling techniques and / or deterministic channel modeling techniques. For example, modeling for sensing in a wireless communication system based on a 6G network of the present disclosure may be based on stochastic geometric channel modeling techniques and / or hybrid with ray tracing channel modeling techniques. Here, the stochastic geometric channel model may be based on various statistical characteristics of the channel state. Furthermore, the hybrid channel model may be based on both ray tracing techniques and stochastic techniques.In a hybrid approach, channels for objects requiring high accuracy and consistency (e.g., targets of interest) can be modeled using ray tracing techniques, while channels for the environment can be modeled using probabilistic techniques.

[0204] FIG. 12 illustrates a procedure related to a sensing operation according to one embodiment of the present disclosure. The embodiment of FIG. 12 may be combined with various embodiments of the present disclosure.

[0205] For example, in a wireless communication system based on a 6G network of the present specification, in the case of a sensing operation in which a terminal participates, the base station may need to confirm (1205) the capability of the terminal for the sensing operation. In this regard, the terminal may be configured to report capability information on whether it supports the sensing operation to the base station. Additionally or alternatively, if the terminal is defined in advance in the standard as supporting the sensing operation, the procedure may be omitted. In addition, in the case of a sensing operation in which only the base station participates, the base station may be configured to report capability information on whether it supports the sensing operation to an entity that configures / controls its sensing operation (e.g., a network entity at an upper level / layer of the base station).

[0206] For example, the base station can perform signaling with the terminal to exchange configuration information related to the sensing operation. For example, the base station can set / instruct the terminal about the mode of the sensing operation (e.g., based on the six types of modes described above), the subject of the sensing operation (e.g., sensing transmitter, sensing receiver), the resource of the sensing operation (e.g., sensing resource as in FIG. 11), the target of utilizing the sensing result (e.g., type of wireless sensing service based on 6G network, trusted third party), channel modeling for sensing (e.g., channel between the base station / terminal and object / environment), etc. (1210). For example, the base station can also set / instruct such information from a network entity at an upper level / layer of the base station.

[0207] For example, the base station and / or the terminal may perform a sensing operation based on the set / instructed information (1215). For example, the base station and / or the terminal may, as a sensing transmitter and / or a sensing receiver, perform procedures such as transmitting a sensing signal, receiving a scattered / reflected signal, deriving sensing data, obtaining a sensing result through processing the sensing data, and providing the sensing result, as in FIG. 9 described above. As an example, in the operation of the base station / terminal described herein, the sensing result provided through the sensing operation may be utilized.

[0208] < Network Energy Saving, NES >

[0209] Network Energy Saving Technology of Rel-18

[0210] Energy conservation at base stations is a key consideration in wireless communication systems, including 3GPP, as it can contribute to building eco-friendly networks by reducing carbon emissions and reducing operational expenditures (OPEX) for telecommunications companies. In particular, the introduction of 5G communications will require higher transmission rates, necessitating base stations to be equipped with more antennas and provide services over wider bandwidths and frequency bands. Consequently, recent studies have shown that base station energy costs have reached as high as 20% of total OPEX. Accordingly, 5G systems are adopting various technologies to reduce energy consumption, known as network energy savings (NES), and the standardization of related technologies will continue.

[0211] Depending on the application of NES technology, the base station can perform operations such as controlling on / off for a certain duration in the time domain, controlling transmission / reception resources for UE-common or UE-specific signals / channels, changing the amount of frequency domain resources, controlling transmission power, or turning on / off antenna ports, transmission-reception points (TRPs), etc. in the spatial domain.

[0212] Figure 13 illustrates an example of the operation procedure of a base station supporting NES technology.

[0213] Referring to Fig. 13, the base station can identify the NES solution(s) to be applied (1305). The NES solution(s) may be related to control of signal transmission and reception (e.g., on / off), beam operation, handover procedures, channel measurement and reporting, etc. The NES solution(s) to be applied may be adaptively selected or predefined based on the current situation (e.g., cell load level, characteristics of connected terminals, etc.). The base station that identified the NES solution(s) can perform signaling for the NES (1310). The specific signaling procedure may vary depending on the identified NES solution(s). For example, the base station may transmit common information about the NES solution(s), transmit configuration information necessary for NES operation to at least one terminal, or transmit control information regarding the progress of the NES operation to at least one terminal. In addition, the base station may receive capability information related to the NES from at least one terminal. Thereafter, the base station performs operations for the NES. At this time, the base station can perform operations for the NES based on the previously performed signaling (1315). That is, based on the system information, configuration information, and control information transmitted through the signaling, the base station can turn on / off the transmission and reception of specific signals, turn on / off elements in the spatial domain, or adjust resources for the transmission and reception of measurement signals.

[0214] Through a procedure similar to that in Fig. 13, NES technology can be implemented. Examples of NES solutions that can be implemented through a procedure similar to that in Fig. 13 are as follows.

[0215] - Intra-system energy saving solution: A RAN node can request a neighboring RAN node to switch at least one SSB beam into its inactive cell, or can perform paging using a limited set of beams to an inactive terminal (e.g., a stationary terminal).

[0216] - Inter-system energy saving solution: NG-RAN nodes that own capacity booster cells can autonomously transition those cells to an inactive state.

[0217] - SSB-less SCell solution: If SSB or SMTC (SSB-based RRM measurement timing configuration) configuration is not provided for the SCell, the UE can obtain timing reference and AGC source from another serving cell. In FR1 or FR2, the base station can configure intra-band CA or inter-band CA including the SCell without SSB transmission, in which case the SSB / SIB transmission can be triggered by the WUS (wake up signal) of the UE. Accordingly, since the period of common channels / signals such as SSB is increased, the base station can stay in the sleep state for a longer time.

[0218] - Cell DTX / DRX solution: In order to reduce the downlink transmission / uplink reception activity time of the base station, a periodic cell DTX / DRX pattern (e.g., active and inactive periods) can be commonly set for terminals within a cell having the corresponding feature. Here, the cell DTX pattern and the cell DRX pattern can be set and activated separately, and up to two cell DTX / DRX patterns can be set per MAC entity. When cell DTX is set and activated, at least one of monitoring for SPS opportunities or monitoring PDCCH can be stopped during the cell DTX inactivity period. When cell DRX is set and activated, at least one of transmission on CG resources or SR transmission can be stopped during the cell DRX inactivity period. Cell DTX / DRX can be activated / deactivated via RRC signaling or L1 group common signaling.

[0219] Parameters such as active duration and cycle may be configured for cell DTX / DRX. The active duration is the period during which the UE receives a PDCCH or SPS opportunity and waits to transmit SR or CG, and the cycle specifies the periodic repetition of the active duration and inactive duration. When both cell DTX and cell DRX are configured, parameters such as active duration and cycle are common. If the base station recognizes an emergency call or a public safety-related service (e.g., MPS or MCS), the network may release or deactivate the cell DTX / DRX configuration so as not to affect the service. In addition, at least some overlap is required between the active duration of the connected mode DRX of the UE and the active duration of the cell DTX / DRX. For example, the connected mode DRX cycle of the UE may be a multiple of the cell DTX / DRX cycle, or vice versa.

[0220] - Conditional handover (CHO) solution: A CHO procedure performed in a way that the execution of the handover is determined by the UE is used while the NES technology is applied (e.g., when the cell activates or deactivates cell DTX / DRX). In this case, the UE can use an NES-specific CHO event to initiate CHO for a candidate cell, and the reception of a DCI that activates the CHO condition(s) set by the NES event indication can be applied as an additional triggering condition for this.

[0221] - Spatial and power domain adaptation solution: To support the gNB for transceiver muting and / or transmit power adaptation, the UE may be configured to report multiple CSI entries in a CSI report based on multiple sub-configurations. Each sub-configuration corresponds to a spatial domain adaptation pattern (e.g., a subset of available spatial elements) and / or a power offset between a data channel (e.g., PDSCH) and CSI-RS. Depending on the application of the spatial and power domain adaptation solution, the CSI configuration, measurement, and / or reporting behavior may be affected.

[0222] Cell DTX / DRX

[0223] To operate a base station in sleep mode for a relatively long period of time without frequent wake-ups, a base station DTX / DRX has been proposed for NES purposes. The base station can reduce energy consumption by utilizing DTX transmission under low system load conditions by setting a cell DTX and setting the on-duration of the C-DRX of terminals within the active period of the cell DTX. Figure 14 illustrates an example of a procedure for cell DTX / DRX operation.

[0224] Referring to FIG. 14, the base station transmits system information to the terminal (1401), and the terminal checks information related to cell DTX / DRX (1402). For example, the system information may include MIB, SIB1, etc. In relation to NES technology, the MIB may include information related to cell barring (e.g., cellBarred), and the SIB1 may include information related to the cell barring status (e.g., cellBarredNES). Specifically, if cellBarred included in the MIB is set to a value indicating that it is not barred (e.g., notBarred), the terminal may determine that the cell is not barred, regardless of whether it supports NES cell DTX / DRX. Conversely, if cellBarred included in the received MIB is set to a value indicating that the cell is barred (e.g., barred), a terminal that does not support NES cell DTX / DRX may determine that the cell is barred. However, if the terminal has the capability to support NES cell DTX / DRX, the terminal checks SIB1 to determine the cell barring status. If cellBarred of MIB is set to barred and cellBarredNES is absent in SIB1, the terminal supporting NES cell DTX / DRX can treat the cell as barred and perform cell reselection to another cell. On the other hand, if cellBarred of MIB is set to barred and cellBarredNES is included in SIB1, the terminal supporting NES cell DTX / DRX can determine that the cell is not barred.

[0225] In the case of FIG. 14, it is assumed that the terminal has the capability to support NES cell DTX / DRX, and the cellBarred of the MIB is set to notBarred, or the cellBarred of the MIB is barred and cellBarredNES is included in SIB1. Accordingly, the terminal performs a random access procedure to connect to the base station (1403), and can perform communication thereafter. At this time, the base station performs a cell DTX / DRX operation and transmits configuration information related to the cell DTX / DRX operation to the terminal (1404). The configuration information related to the cell DTX / DRX operation (e.g., CellDTXDRX-Config) includes at least one parameter related to the cell DTX / DRX, and may include, for example, at least one of an on-duration timer, a cycle start offset, a slot offset, a configuration type (e.g., DTX, DRX, or DTX-DRX), and an activation state of the DTX / DRX (e.g., active, inactive). Additionally, the configuration information may further include information for receiving and interpreting cell DRX / DRX-related control information (e.g., DCI-related information).

[0226] Thereafter, the base station transmits control information related to cell DTX / DRX to the terminal (1405). The control information related to cell DTX / DRX may include DCI having a designated format (e.g., format 2_9). If an operation for a serving cell according to at least one of the cell DTX operation and the cell DRX operation is configured by configuration information (e.g., cellDTXDRX-Config), the terminal may check a set of search spaces (e.g., a set of Type3-PDCCH CSS) for monitoring a PDCCH conveying control information of a designated format during an active time through a higher layer parameter (e.g., SearchSpace), and may obtain a location of information about the serving cell within the control information through a higher layer parameter (e.g., positionInDCI-cellDTRX). Then, the terminal may obtain control information based on the identified set of search spaces and location.

[0227] Control information related to cell DTX / DRX may be used to indicate activation or deactivation of cell DTX and / or cell DRX, and / or to provide an NES-mode indicator, and may include, for example, at least one block including a cell DTX / DRX indicator and an NES-mode indicator. In this case, when the serving cell is configured as a SUL (supplementary uplink) carrier, the indication of activation or deactivation of cell DRX by the cell DTX / DRX indicator may be applied to both the UL carrier and the SUL carrier.

[0228] Thereafter, the terminal and the base station can perform communication based on the cell DTX / DRX (1406). Specifically, the base station can turn on / off the transmission and reception of signals according to the settings related to the cell DTX / DRX, and accordingly, the terminal can selectively monitor the signal from the base station. During the DTX-OFF, the base station enters a sleep mode to reduce energy consumption. At this time, the base station DTX cycle can be aligned with the cycle of the terminal DRX. The base station DTX-ON can completely cover the DRX-ON of the terminal. Furthermore, the base station can align the transmission of Xn / NG and the transmission of Uu for the purpose of NES. The DTX / DRX mechanism triggers the switching of reference signal resource set groups, and the base station can perform a dormancy-like behavior of sparsely transmitting or not transmitting SSB, SIB, and CSI-RS to reduce energy consumption. The terminal can sparsely receive or not receive a downlink signal / channel depending on the settings of the base station. Once the base station DTX / DRX operation is triggered, during the DTX / DRX OFF period, the terminal can discontinuously receive the corresponding CSI-RS, SSB, or PDCCH.

[0229] SSB-less SCell

[0230] Figure 15 illustrates an example of a procedure for CA operation using SSB-less SCell.

[0231] Referring to FIG. 15, the base station transmits configuration information for the SCell to the terminal. That is, the base station transmits configuration information for CA to provide a service to the terminal through CA operation. Here, the CA operation may be intra-band CA or inter-band CA. For example, the configuration information for the SCell may include information related to SCell addition (e.g., sCellToAddModList), and specifically, may include a cell index, a physical cell identifier, information related to DL-UL configuration, information related to BWP, information related to cell DTX / DRX, information related to downlink frequency (e.g., FrequencyInfoDL), etc. Then, the terminal may determine the configuration for the CA operation and perform communication using the PCell and SCell of the base station. At this time, the terminal may confirm that the SCell is an SSB-less SCell based on the information related to the downlink frequency included in the configuration information, and may check the related parameters. For example, a terminal can determine that an SCell is an SSB-less SCell by checking for the presence of a parameter indicating that it is an SSB-less SCell (e.g., SSBlessSCell), and can determine the timing reference and AGC source for the SCell based on information about the reference cell (e.g., referenceCell). In the case of Fig. 15, the reference cell may be a PCell. Therefore, the terminal can use the PCell as a timing reference and AGC source for communication on the SCell.

[0232] Conditional Hand Over (CHO)

[0233] Figure 16 illustrates an example of a Conditional Handover (CHO) procedure. The order of the operations illustrated in Figure 16 may vary depending on the case.

[0234] Referring to FIG. 16, the base station transmits configuration information for CHO to the terminal (1601). The configuration information for CHO may include information related to conditional reconfiguration (e.g., ConditionalReconfiguration, CondReconfigToAddModList) and information related to configuration for reporting (e.g., ReportConfigNR). Here, the information related to configuration for reporting may include information related to events related to reporting, identifiers of the events (e.g., condEventId), information indicating whether it is an NES-specific CHO event (e.g., nesEvent), etc. In the example of FIG. 16, event information indicating that it is an NES-specific CHO event is received.

[0235] The base station transmits information for enabling an NES-specific CHO execution condition to the terminal (1602). The information for enabling the NES-specific CHO execution condition may be transmitted via control information of a specified format (e.g., DCI format 2_9). The information for enabling the NES-specific CHO execution condition may be referred to as an NES-mode indicator, for example, as 1-bit information, which indicates enabling the NES-specific CHO execution condition when a related upper layer parameter (e.g., nesEvent) is set and the serving cell of the related block in the corresponding DCI is a primary cell.

[0236] Thereafter, the terminal performs a measurement (1603) and transmits a measurement report to the base station (1604). The base station determines a CHO based on the measurement report and performs signaling for a handover request with the neighboring base stations indicated by the measurement report (1606). The base station determines the neighboring base stations that have confirmed admission through signaling as candidate base stations and transmits information about the candidate base stations to the terminal (1607). Accordingly, the terminal evaluates the CHO execution conditions for the candidate base stations (1608). Accordingly, when a candidate cell satisfying the condition is determined, the terminal detaches from the old cell and synchronizes to the new cell (1609). At this time, since the terminal has previously received event information indicating that it is a NES-specific CHO event and also received information enabling the NES-specific CHO execution condition, it can determine whether the event is satisfied. In other words, if a NES-mode indicator is received through a lower layer and conditional triggering configuration information (e.g., condTriggerConfig) includes information (e.g., nesEvent) indicating that the event is a NES-specific CHO event, the terminal can determine that the event associated with the corresponding measurement identifier (e.g., measId) is satisfied, and thus determine that the CHO execution condition is satisfied.

[0237] NES Enhancement

[0238] 3GPP NR release 19 will discuss NES enhancements, with (1) On-demand SSB, (2) On-demand SIB1 transmission, and (3) adaptation of common signal / channel transmissions being considered as key targets.

[0239] (1) On-demand SSB

[0240] A method to reduce energy consumption by having a base station transmit SSB on a specific cell through an on-demand SSB process and not transmit SSB on that cell when an on-demand SSB process is not available can be discussed. In the existing NR system, SSB must be transmitted periodically and constantly for purposes such as time / frequency synchronization or RRM measurement, making it difficult to reduce energy consumption even when the base station has no data to receive or send. Considering this, the base station can reduce base station energy consumption by not performing SSB transmission until the on-demand SSB process is involved and then performing SSB transmission. The on-demand SSB process can be triggered using one of the following methods:

[0241] 1) The terminal requests SSB transmission from the base station by transmitting an uplink signal / channel (e.g., PRACH, PUCCH, PUSCH, SRS in the NR system).

[0242] 2) Requesting SSB transmission from base station (or TRP) #1 to base station (or TRP) #2 through an interface between base stations (e.g., Xn interface in NR system) or backhaul signaling.

[0243] 3) Signaling whether SSB transmission is possible for the corresponding Scell ​​through Scell ​​activation / deactivation signaling.

[0244] Considering coexistence with existing NR terminals, Release 19 is limited to on-demand SSB operation for connected mode terminals and SCells. However, in future releases or next-generation communication systems, on-demand SSB operation (for SSB transmission on PCell) considering inactive or idle mode terminals or initially connected terminals may be defined. In addition, carrier aggregation (CA) including the SCell can be applied to both intra-band CA and inter-band CA, and the SSB on the SCell transmitted through the on-demand SSB process can be utilized for at least functionality such as time / frequency synchronization, L1 / L3 measurement, and SCell activation.

[0245] (2) On-demand SIB1 transmission

[0246] A method to reduce energy consumption by having the base station transmit SIB1 for a specific cell through the on-demand SIB1 process and not transmit SIB1 for the cell when there is no on-demand SIB1 process can be discussed. In the existing NR system, SIB1 containing system information, random access information, etc. for initial access or idle mode terminals to access a cell had to be provided periodically, so it was difficult to reduce energy consumption even when the base station had no data to receive or send. Considering this, the base station can reduce base station energy consumption by not performing SIB1 transmission until the on-demand SIB1 process is accompanied and then performing SIB1 transmission. The on-demand SIB1 process can trigger the base station's SIB1 transmission by the terminal transmitting an uplink signal / channel (e.g., PRACH in the NR system). Specifically, the following scenarios can be considered but may not be limited to the following scenarios.

[0247] 1) Scenario 1: As in (a) of Fig. 17, when a UE receives an SSB (and / or other downlink signal / channel) from a cell#1 and recognizes that SIB1 is not transmitted on the cell#1, the UE can trigger SIB1 transmission by transmitting a signal requesting SIB1 (for convenience, the signal is referred to as a WUS (wake-up signal)) based on information provided in the SSB (and / or other downlink signal / channel) and / or predetermined information. The base station that receives the WUS can transmit a specific DL signal / channel on cell#1 in response thereto, and (or) transmit SIB1 on cell#1 (without transmitting the DL signal / channel).

[0248] 2) Scenario 2: As in (b) of Fig. 17, a terminal may attempt to camp on cell#2 when it receives an SSB (and / or other downlink signal / channel such as SIB1) from a cell#1 and recognizes that SIB1 is not transmitted on the corresponding cell#2. The terminal may trigger SIB1 transmission for cell#2 by transmitting a signal requesting SIB1 (i.e., WUS) on cell#1 based on information provided in the received SSB (and / or other downlink signal / channel such as SIB1) and / or predetermined information. The base station receiving the WUS may transmit a specific DL signal / channel (on cell#1 or cell#2) in response thereto, and may transmit SIB1 for cell#2 on cell#1 or cell#2 (or without transmitting the DL signal / channel).

[0249] 3) Scenario 3: As in (c) of Fig. 17, a terminal that receives an SSB (and / or other downlink signal / channel such as SIB1) from a cell#1 and recognizes that SIB1 is not transmitted on the corresponding cell#2 may attempt to camp on cell#2. The terminal may trigger SIB1 transmission for cell#2 by transmitting a signal requesting SIB1 (i.e., WUS) on cell#2 based on information provided in the received SSB (and / or other downlink signal / channel such as SIB1) and / or predetermined information. The base station that receives the WUS may transmit a specific DL signal / channel (on cell#1 or cell#2) in response thereto, and may transmit SIB1 for cell#2 on cell#1 or cell#2 (or without transmitting the DL signal / channel).

[0250] (3) adaptation of common signal / channel transmissions

[0251] Methods for reducing energy consumption by modulating the transmission of common signals / channels such as SSB, PRACH, and paging by the base station can be discussed. While completely disabling SSB can significantly reduce the energy consumption of the base station, the absence of SSB, which performs functions such as time / frequency synchronization and RRM measurement, may not guarantee stable operation for the corresponding cell from the UE's perspective. Considering this, energy savings at the base station can be achieved by varying the SSB transmission pattern (e.g., transmission period, period per SSB candidate index(es), SSB candidate index(es) transmitted within a transmission period, transmission power, etc.) depending on the situation.

[0252] In the case of PRACH resources, since the base station cannot know when the terminal will transmit the PRACH in the case of contention-based random access, energy consumption may increase because the base station always attempts to receive within the configured PRACH resources. Considering this, energy of the base station can be saved by applying a method to adjust the amount of PRACH resources (e.g., adjusting the period of PRACH resources, adjusting the amount of resources through instructions such as pre-configuring PRACH resource set #1 and set #2 and turning on only one set or both sets, or providing the corresponding RACH resource amount uniformly or non-uniformly for each SSB index).

[0253] In the case of paging, previously, paging frames (PF) and / or paging occasions (PO) were distributed along the time axis within a DRX cycle (or paging cycle), and the terminal attempted to receive paging at a specific PF / PO derived from its ID-based formula. From the base station's perspective, if paging was to be transmitted to multiple terminals simultaneously, it may have to wake up frequently to transmit paging. To reduce base station energy consumption due to this, it is possible to consider arranging PFs and / or POs for paging reception as close to the time axis as possible or arranging different frequency resources within the same time.

[0254] Adaptive synchronization signal / channel operation

[0255] Based on the above-described discussion, this specification discloses an adaptive operation method of a synchronization signal (or synchronization channel) that can be used in a next-generation wireless communication system.

[0256] For communication between a base station and a terminal, the base station can transmit a synchronization signal (SS), and the terminal can obtain time and / or frequency synchronization by receiving the SS. In the 5G NR system, the SS consists of a primary SS (PSS) and a secondary SS (SSS), and the terminal can obtain physical cell ID information through the combination of the PSS and SSS.

[0257] Even in 6G communication standards, an SS may include at least one PSS and / or at least one SSS. For example, information that may be provided / obtained through an SS may include some or all of the following: physical cell ID, TRP ID, and beam index information.

[0258] Before describing the proposed new SS transmission structure, we first briefly describe SS in the existing 5G system. In a 5G NR system, the PBCH is transmitted across 4 OFDM symbols along with the PSS / SSS, and the corresponding block is called an SSB (SS / PBCH block). The PBCH can include timing information such as the system frame number (SFN), half frame indicator, and SSB index; PRB grid information such as the sub-carrier offset; sub-carrier spacing / CORESET / Type0-PDCCH CSS set information for PDCCH reception that schedules the SIB1 PDSCH; DMRS type A position information; cell barring information; and CRC. The UE can obtain time / frequency synchronization and physical cell ID-related information through the PSS / SSS, and additional timing information and information necessary for SIB1 reception through the PBCH. Based on this information, the UE can receive SIB1, obtain DL / UL BWP and random access procedure-related information, attach to the corresponding cell, and initiate communication.

[0259] Table 1 is part of the 5G NR standard document TS 38.213 Rel.18.

[0260]

[0261]

[0262]

[0263]

[0264] As shown in Table 1, the 5G NR standard defines the location of SSB by classifying cases according to sub-carrier spacing (SCS). In addition, depending on the frequency range (FR) and / or frequency band and / or whether it is paired spectrum (e.g., FDD) or unpaired spectrum (e.g., TDD) and / or whether shared spectrum channel access is applied or not (e.g., unlicensed band or licensed band), L max (This refers to the maximum SSB index or number of SSB beams, and is denoted as L_max for convenience below) and N max (This refers to the maximum number of candidate SSB indices, and is denoted as N_max for convenience below) The value is defined differently.

[0265] For example, for FR2, the L_max value is 64. For FR1 and 15 kHz SSB, the L_max value is 4 in the band below 3 GHz and 8 in the band above 3 GHz. For FR1 and 30 kHz SSB, 1) for FDD, the L_max value is 4 in the band below 3 GHz and 8 in the band above 3 GHz, and 2) for TDD, the L_max value is 4 in the band below 1.88 GHz and 8 in the band above 1.88 GHz.

[0266] For Case A / C in Table 1 above, it is stated that the symbol index starts from the half frame boundary, and the SSB is located from the symbol index of {2,8}+14n.

[0267] As an example, Fig. 18 illustrates Case A / C SSB pattern when L_max=8. Referring to Fig. 18, one slot consists of 14 symbols, and 0 / 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / A / B / C / D represent symbol index 0 / 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 10 / 11 / 12 / 13, respectively. In addition, P represents PSS, and S represents time / frequency domain in which SSS is transmitted (i.e., PSS / SSS are 1 symbol / 12 PRBs each). In addition, the symbol following PSS, the frequency domains above / below the symbol including SSS, and the channel transmitted in the symbol following SSS represent PBCH, and the numbers 1 to 8 written in the PBCH represent SSB indexes.

[0268] Meanwhile, in Fig. 18, each grid at different left / right positions in the time domain may equally mean 1 symbol, but each grid at different upper / lower positions in the frequency domain may not mean a frequency resource unit of the same size. For example, when 1 SSB is composed of a total of 240 subcarriers (e.g., 20 RBs), the grid to which the PSS( / SSS) is mapped (and grids at the same frequency position as the corresponding grid) may include 127 subcarriers, but the grid immediately below or above the grid to which the PSS( / SSS) is mapped (and grids at the same frequency position as the corresponding grid) may include 56 or 57 subcarriers. In addition, for convenience, the PBCH channel and the PBCH DMRS are not separately illustrated in Fig. 18.

[0269] In this way, in the time domain direction, the grids represent the same time resources (e.g., symbols), but in the frequency domain direction, different upper / lower position grids can represent sets of frequency resources (e.g., subcarrier sets or RB sets) with different numbers of elements, and this can be applied not only to FIG. 18 but also to the SSB transmission example drawings described below.

[0270] Considering that transmission of not only SSB but also DL control / data signals / channels or UL control / data signals / channels can be multiplexed within a single slot, a time gap (e.g., symbol gap and / or slot gap) is introduced between SSBs.

[0271] However, even for base stations with no traffic or associated terminals, it may not be efficient from the standpoint of base station energy consumption to always perform SSB transmission for terminals that may attempt initial connection. For example, if L_max=8 and 15 kHz SCS, and an SSB burst consisting of 8 SSB indices is transmitted as shown in Fig. 18, the base station RF must always be turned on for SSB transmission for 4 msec every 20 msec, which is the default periodicity, even if there is no data traffic to send.

[0272] To address these shortcomings, this specification considers SSB / SSB burst examples for reducing the energy consumption of such base stations. In the examples described below, slots and symbols represent upper and lower time resource units of different lengths, respectively. A slot is a time resource having a first length, and a symbol may be replaced with a time resource having a second length that is shorter than the first length. For example, the first length may be related to a TTI.

[0273] In the prior art / contribution / standard, the terms SSB burst / block and SS burst / block have been used interchangeably to refer to the SS+PBCH block structure. Therefore, the terms SSB burst / block and SS burst / block have been understood to have virtually the same meaning, and both assume that the PBCH is included in the burst / block. However, in some embodiments of the present specification, the terms SS burst / block or SSB / SSB burst may refer to SS excluding PBCH (e.g., PSS / SSS), in which case, PBCH burst / block may refer to a PBCH (excluding SS) structure. Meanwhile, a PBCH block included in a PBCH burst may also be simply referred to as PBCH.

[0274] Hereinafter, examples of SSB (including / excluding PBCH) transmission [SSB Example #y] that can be used for [Proposal #x] described below will be described first. The described [SSB Example #y] are only intended to aid in understanding [Proposal #x], and the application of [Proposal #x] is not necessarily construed as presupposing the application of [SSB Example #y]. In addition, in the description below, the distinction of [SSB Example #y] and / or the distinction of [Proposal #x] and the indices x and y assigned to each are only for the convenience of explanation and do not necessarily mean that each index is implemented in an independent form, and depending on the implementation, at least some of them may be implemented in a combined form or each may be implemented individually.

[0275] [SSB Example #1] Minimizing the gap between SSBs while reusing the NR SSB structure as much as possible.

[0276] SSB Example #1 assumes that the NR SSB structure is reused as much as possible, with one SSB consisting of 4 symbols. However, the sequence of PSS / SSS / PBCH DM-RS, the configuration of PBCH payload, the time / frequency axis location of PSS / SSS / PBCH (within SSB), and / or the size of frequency resources occupied by PSS / SSS / PBCH may differ from those defined in the existing 5G NR standard.

[0277] [SSB Example #1-1] Configure L_max SSBs by minimizing the gap between SSBs.

[0278] Figure 19 illustrates an example of SSB transmission based on SSB Example # 1-1.

[0279] Referring to Fig. 19, a maximum of 3 SSBs are set for each Slot related to an SSB burst, and the SSBs can be consecutive within the same slot without a time gap. Through this method, the number of slots that L_max SSBs span on the time axis can be reduced. Compared to the SSB burst configuration as shown in Fig. 18, the energy consumption of the base station can be reduced by reducing the time it takes for the base station to transmit L_max SSBs from 4 msec per SSB period to 3 msec or less. For example, when an SSB burst is transmitted for each SSB period, the time taken from the first SSB transmission to the last SSB transmission of the SSB burst can be reduced to 3 msec or less in the method of Fig. 19, compared to 4 msec in the case of Fig. 18.

[0280] Additionally, by leaving some symbols for each slot empty (without SSB mapping), there is an advantage that DL control / data signals / channels or UL control / data signals / channels can be transmitted through those symbols.

[0281] In Fig. 19, a slot structure consisting of 14 symbols is assumed and a structure in which the first two symbols are empty is considered. However, the two symbols to which SSB is not mapped may be the last symbols in the slot or any two symbols within the 14 symbols. In addition, Proposal #1-1 can be extended to a slot structure consisting of a number of symbols different from 14 symbols.

[0282] Figure 20 illustrates another example of SSB transmission based on SSB Example # 1-1.

[0283] Compared to Figure 19, in Figure 20, all symbols in the slot associated with the SSB burst are used for SSB transmission, and there are no symbols that are not mapped to SSBs and are left empty. Therefore, no time gap is established between SSBs. Furthermore, if no time gap is established at all, a single SSB (e.g., SSB #4) may be transmitted across a slot boundary.

[0284] By positioning the SSBs without a symbol gap, as shown in Fig. 20, the number of slots spanned by L_max SSBs on the time axis can be reduced. Compared to the SSB burst configuration as shown in Fig. 18, the energy consumption of the base station can be reduced by reducing the time it takes for the base station to transmit L_max SSBs from 4 msec to 3 msec or less per SSB period. Compared to spanning approximately 40 slots when L_max=64, as in Case D, applying this method allows 64 SSBs to be transmitted by spanning only 19 slots.

[0285] Although Fig. 20 assumes a slot structure consisting of 14 symbols, it can be extended to slot structures consisting of a different number of symbols than 14. Furthermore, while the starting position of the SSB burst is proposed as the first symbol of slot n, it can also be extended to start from any arbitrary symbol.

[0286] [SSB Example #1-2] A method to configure N_max (>L_max) candidate SSBs, which are more than L_max, by minimizing the gap between SSBs, and to transmit actual transmissions less than L_max.

[0287] Reducing the gap between SSBs can save energy at the base station by reducing the time it takes to transmit the entire SSB burst. If there is a (DL) control / data signal / channel that needs to be transmitted at the same time as the SSBs without a time gap, the (DL) control / data must be FDM'd and transmitted at the same time as the SSBs. In this case, since the beam of the (DL) control / data signal / channel must change every time the SSB index changes, multiplexing may not be easy. For example, assuming that SSB indices 1 / 2 / 3 are all transmitted in slot n of FIG. 19, if there was a PDSCH transmitted on symbols 6 / 7 / 8 / 9 of slot n (from the base station's perspective), the PDSCH would have the same beam as SSB index 2, but from symbol 10 onwards, the beam must be changed to match SSB index 3, making it difficult to continuously transmit the PDSCH from symbol 10 (following symbols 6 / 7 / 8 / 9).

[0288] In this way, there may be a trade-off relationship between the energy saving reduction effect of the base station and the multiplexing efficiency.

[0289] Taking this into account, according to one embodiment, N_max candidate SSBs, which are more than L_max, can be configured in advance, and transmission of at most L_max SSBs can be restricted. The base station can select and transmit SSBs less than or equal to L_max by minimizing the gap between SSBs as in SSB Example #1-1 among N_max candidate SSBs (if it is expected that there will be many cases with low traffic or if saving base station energy consumption is a priority), or can select and transmit SSBs less than or equal to L_max by applying a certain degree of symbol / slot gap between SSBs (if it is considered that most cases are frequency bands with high traffic or if multiplexing efficiency between SSBs and other signals / channels is a priority).

[0290] Figure 21 illustrates an example of SSB transmission based on proposal #1-2.

[0291] Referring to Fig. 21, it can be defined that 3 SSBs can be positioned within one slot, up to a total of N_max (12 in the example). In this state, the base station can select and transmit up to L_max SSBs among the N_max SSBs. For example, if SSB index 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 is selected, the base station energy saving effect can be obtained in the same way as in Fig. 19, and if SSB index 1 / 3 / 4 / 6 / 7 / 9 / A / C is selected, the multiplexing efficiency can be improved in a similar way as in Fig. 18.

[0292] In Fig. 21, a slot structure consisting of 14 symbols is assumed and a structure in which the first two symbols are empty is considered, but the two symbols may be the last symbols in the slot or any two symbols in the 14 symbols, and the structure may be extended to a slot structure consisting of a number of symbols different from 14 symbols.

[0293] Figure 22 illustrates another example of SSB transmission based on proposal #1-2.

[0294] Compared to Fig. 21, in Fig. 22, all symbols of a slot related to an SSB burst are associated with candidate SSB(s), and there is no symbol that is not associated with any candidate SSB, so there is no symbol that is always left empty and not mapped to an SSB. However, if the candidate SSB is not selected, there may be cases where actual SSB transmission is not performed on the symbol associated with it and it is left empty. In addition, in Fig. 22, one candidate SSB (e.g., SSB #4) may be located across a slot boundary.

[0295] Referring to Fig. 22, it can be defined that SSBs can be positioned without a symbol gap between SSBs, up to a total of N_max (14 in the example). In this state, the base station can select and transmit up to L_max SSBs among N_max SSBs. For example, if SSB index 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 is selected, the base station energy saving effect can be obtained in the same way as in Fig. 20, and if SSB index 1 / 3 / 5 / 7 / 8 / A / C / E is selected, the multiplexing efficiency can be improved in a similar way as in Fig. 18.

[0296] Although Fig. 22 assumes a slot structure consisting of 14 symbols, it can be extended to slot structures consisting of a different number of symbols than 14. Furthermore, while the starting position of the SSB burst is proposed as the first symbol of slot n, it can also be extended to a method where it starts from any arbitrary symbol.

[0297] Meanwhile, in proposal #1-2, by defining N_max candidate SSBs, which are more than L_max, at least one of the following may need to be additionally considered.

[0298] - A larger number of PBCH DM-RS sequences may be required to indicate an increased SSB index. For example, when SSB index information is provided based on PBCH DM-RS sequence information, a larger number of PBCH DM-RS sequences may be required due to the increased SSB index.

[0299] - The number of bits in the field indicating the SSB index in the PBCH payload may increase. For example, if L_max is 8, 3 bits are needed to indicate the SSB index in the PBCH payload, but if N_max is 14, 4 bits may be needed to indicate the SSB index in the PBCH payload. For example, when a field providing SSB index information is included in the PBCH payload (e.g., MIB), the size of the field may increase due to an increase in the SSB index.

[0300] - The amount of information indicating the actual transmitted SSB index can be increased through cell-specific higher layer signaling such as SIB and / or UE-specific higher layer signaling. For example, if L_max is 8, an 8-bit bitmap can be used to indicate which SSB index is actually transmitted, but if N_max is 14, a 14-bit bitmap (where the lowest / highest SSB index can be mapped to the LSB and the highest / lowest SSB index can be mapped to the MSB) can be used to indicate which SSB index is actually transmitted, and in this case, the maximum number of SSB indices signaled as '1' through the 14-bit bitmap can be limited to L_max.

[0301] - When a terminal receives a PDSCH including SIB1 (or receives a PDSCH before receiving signaling about which SSB among N_max SSB indices is actually transmitted), it may not know which SSB among N_max SSB indices is actually transmitted, and therefore it may receive the PDSCH assuming that resources of all N_max candidate SSBs are not available.

[0302] Meanwhile, considering a frame structure in which the CP length changes every 0.5 msec (e.g., in normal CP 15 kHz, the CP length of symbol 0 / 7 is 160 T_s, while the CP length of the remaining symbols is 144 T_s, where T_s can mean "basic time unit for LTE" as defined in TS 38.211 specification in relation to OFDM modulation), it may not be desirable in terms of implementation complexity of a terminal attempting an initial connection to have a symbol with a changing CP in the middle of an SSB (e.g., the first symbol of a slot in existing NR or a symbol of a slot with a different CP length set). To address this, a constraint may be imposed that an SSB burst structure such as in FIG. 19 / FIG. 21 is applied to the first SCS (e.g., 30 kHz SCS) or higher, or an SSB burst structure such as in FIG. 20 / FIG. 22 is applied to the second SCS (e.g., 60 kHz SCS) or higher. For example, whether it is allowed to include symbols with different CP lengths (e.g., whether it is allowed to map SSBs starting from the first symbol of a slot or to map SSBs across slot boundaries) may be determined based on the SCS.

[0303] When the SSB burst structure proposed in SSB Example #1 is applied, the UE can assume that SSBs of the structure are transmitted at the default periodicity (the SSB cycle assumed when the UE is not explicitly signaled with SSB periodicity information, e.g., 20 msec) upon initial connection. When a specific SSB is detected, the UE can obtain the index of the SSB through the PBCH DM-RS and / or PBCH payload and recognize the slot / symbol index (i.e., as defined in the specification) where the index is transmitted, thereby determining the frame boundary.

[0304] [SSB Example #2] Reduce the number of symbols occupied by one SSB by reducing the time / frequency resources allocated for PBCH.

[0305] In SSB Example #2, we propose a method to reduce the number of symbols occupied by one SSB by reducing the time and / or frequency resources allocated for PBCH compared to the NR SSB structure.

[0306] The above description may be referred to to help understanding Proposal #2, unless explicitly stated to have been changed in Proposal #2 or if it conflicts with the previous proposal. For example, as in SSB Example #1, in Proposal #2, the sequence of PSS / SSS / PBCH DM-RS and / or PBCH payload configuration and / or time / frequency axis position of PSS / SSS / PBCH (within SSB) and / or size of frequency resource occupied by PSS / SSS / PBCH may be different from those defined in the existing 5G NR standard.

[0307] [SSB Example #2-1] Configure L_max SSBs by minimizing the gap between SSBs.

[0308] Figure 23 illustrates an example of SSB transmission based on SSB Example #2-1.

[0309] Referring to Fig. 23, a structure can be introduced in which one SSB is composed of a total of three OFDM symbols. By positioning four SSBs (without a time gap) within one slot, the number of slots spanned by L_max SSBs on the time axis can be reduced. Compared to the SSB burst configuration as in Fig. 18, the energy consumption of the base station can be reduced by reducing the time taken for the base station to transmit L_max SSBs from 4 msec per SSB period to less than 2 msec. In addition, by leaving some symbols empty in each slot, there is an advantage in that DL control / data signals / channels or UL control / data signals / channels can be transmitted through the corresponding symbols.

[0310] Meanwhile, by providing a symbol gap between the PSS and SSS within the same SSB, there may be a performance improvement effect when utilizing the carrier frequency offset (CFO) using the PSS / SSS. For example, the PSS can be located at symbols 2 / 5 / 8 / 11, and the corresponding SSS can be located at symbols 4 / 7 / 10 / 13, respectively. In addition, to match the number of RBs allocated for the PBCH to a level similar to the PBCH of FIG. 18, the RB(s) around the PSS can be utilized to transmit the PBCH, or the total number of RBs in the SSB (or PBCH) region can be increased to 20 or more.

[0311] In Fig. 23, a slot structure consisting of 14 symbols is assumed and a structure in which the first two symbols are empty is considered, but the two symbols may be the last symbols in the slot or any two symbols in the 14 symbols, and the structure may be extended to a slot structure consisting of a number of symbols different from 14 symbols.

[0312] Figure 24 illustrates another example of SSB transmission based on SSB Example #2-1.

[0313] As shown in Fig. 24, a structure can be introduced in which one SSB is composed of a total of two OFDM symbols. At this time, by positioning four SSBs in one slot, the number of slots spanned by L_max SSBs on the time axis can be reduced. Compared to the SSB burst configuration as shown in Fig. 18, the energy consumption of the base station can be reduced by reducing the time taken for the base station to transmit L_max SSBs from 4 msec per SSB period to less than 2 msec. In addition, by leaving some symbols empty in each slot, there is an advantage in that DL control / data signals / channels or UL control / data signals / channels can be transmitted through the corresponding symbols.

[0314] At this time, in order to match the number of RBs allocated for PBCH to a level similar to the PBCH of Fig. 18, RB(s) around PSS can be used as PBCH or the total number of RBs in the SSB (or PBCH) area can be increased to 20 or more.

[0315] In Fig. 24, a slot structure consisting of 14 symbols is assumed and a structure of 2 empty symbols - 2 SSBs - 2 empty symbols - 2 SSBs - 2 empty symbols is considered, but any 6 symbols within the 14 symbols can be configured as empty symbols, and 4 or more 2-symbol SSBs can be located within one slot, and it can be extended to a slot structure consisting of a number of symbols different from 14 symbols.

[0316] [SSB Example #2-2] By minimizing the gap between SSBs, N_max (>L_max) candidate SSBs are configured, which is more than L_max, and actual transmission is performed with L_max or less.

[0317] As explained in SSB Example #1-2, there is a trade-off relationship between the energy saving reduction effect of the base station and the multiplexing efficiency. Considering this, the method of pre-configuring N_max candidate SSBs, which is more than L_max, and limiting the transmission of at most L_max SSBs can also be applied to the SSB burst structure based on SSB Example #2-1. Among the N_max candidate SSBs, the base station can select and transmit SSBs less than or equal to L_max by minimizing the gap between SSBs as in SSB Example #2-1 (if it is expected that there will be many cases with low traffic or if it prioritizes saving base station energy consumption), or (if it considers that it is mostly a frequency band with high traffic or if it prioritizes multiplexing efficiency between SSBs and other signals / channels) it can select and transmit SSBs less than or equal to L_max by applying a certain symbol / slot gap between SSBs.

[0318] Figure 25 illustrates an example of SSB transmission based on SSB Example # 2-2.

[0319] Referring to Fig. 25, it can be defined that 4 SSBs are positioned within one slot, and up to a total of N_max (16 in the example) candidate SSBs are possible. In this state, the base station can select and transmit up to L_max SSBs among the N_max candidate SSBs. For example, if SSB index 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 is selected, the base station energy saving effect can be obtained as in Fig. 23, and if SSB index 1 / 3 / 5 / 7 / 9 / B / D / F is selected, the multiplexing efficiency can be improved.

[0320] By providing a symbol gap between the PSS and SSS, there may be a performance improvement effect when utilizing the PSS / SSS for carrier frequency offset (CFO). For example, the PSS can be located at symbols 2 / 5 / 8 / 11, and the corresponding SSS can be located at symbols 4 / 7 / 10 / 13, respectively. In addition, to match the number of RBs allocated for the PBCH to a level similar to the PBCH in FIG. 18, the RB(s) around the PSS can be utilized as the PBCH, or the total number of RBs in the SSB (or PBCH) region can be increased to 20 or more.

[0321] In Fig. 25, a slot structure consisting of 14 symbols is assumed and a structure in which the first two symbols are empty is considered, but the two symbols may be the last symbols in the slot or any two symbols in the 14 symbols, and the structure may be extended to a slot structure consisting of a number of symbols different from 14 symbols.

[0322] Figure 26 illustrates another example of SSB transmission based on SSB Example # 2-2.

[0323] Referring to Fig. 26, it can be defined that SSBs can be positioned without a symbol gap between SSBs, and up to a total of N_max (16 in the example) candidate SSBs can be possible. In this state, the base station can select and transmit up to L_max SSBs among the N_max candidate SSBs. For example, if SSB index 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 is selected, the base station energy saving effect can be obtained as in Fig. 24, and if SSB index 1 / 3 / 5 / 7 / 9 / B / D / F is selected, the multiplexing efficiency can be improved.

[0324] At this time, in order to match the number of RBs allocated for PBCH to a level similar to the PBCH of Fig. 18, RB(s) around PSS can be used as PBCH or the total number of RBs in the SSB (or PBCH) area can be increased to 20 or more.

[0325] In Fig. 26, a slot structure consisting of 14 symbols is assumed and a structure of 2 empty symbols - 2 SSBs - 2 empty symbols - 2 SSBs - 2 empty symbols is considered, but any 6 symbols within 14 symbols can be configured as empty symbols, and 4 or more 2-symbol SSBs can be located within one slot, and it can be extended to a slot structure consisting of a number of symbols different from 14 symbols.

[0326] In SSB Example #2-2, by defining N_max candidate SSBs, which are more than L_max, we may need to additionally consider at least one of the following:

[0327] - A larger number of PBCH DM-RS sequences may be required to indicate an increased SSB index. For example, when SSB index information is provided based on PBCH DM-RS sequence information, a larger number of PBCH DM-RS sequences may be required due to the increased SSB index.

[0328] - The number of bits in the field indicating the SSB index in the PBCH payload may increase. For example, if L_max is 8, 3 bits are needed to indicate the SSB index in the PBCH payload, but if N_max is 16, 4 bits may be needed to indicate the SSB index in the PBCH payload. For example, when a field providing SSB index information is included in the PBCH payload (e.g., MIB), the size of the field may increase due to an increase in the SSB index.

[0329] - The amount of information indicating the actual transmitted SSB index can be increased through cell-specific higher layer signaling such as SIB and / or UE-specific higher layer signaling. For example, if L_max is 8, an 8-bit bitmap can be used to indicate which SSB index is actually transmitted, but if N_max is 16, a 16-bit bitmap (where the lowest / highest SSB index can be mapped to the LSB and the highest / lowest SSB index can be mapped to the MSB) can be used to indicate which SSB index is actually transmitted, and in this case, the maximum number of SSB indices signaled as '1' through the 16-bit bitmap can be limited to L_max.

[0330] - When a terminal receives a PDSCH including SIB1 (or receives a PDSCH before receiving signaling about which SSB among N_max SSB indices is actually transmitted), it may not know which SSB among N_max SSB indices is actually transmitted, and therefore it may receive the PDSCH assuming that resources of all N_max candidate SSBs are not available.

[0331] Meanwhile, considering the frame structure in which the CP length changes every 0.5 msec, it may not be desirable in terms of the implementation complexity of the terminal attempting the initial connection to have a symbol with a different CP located in the middle of an SSB. To this end, instead of the SSB burst structure as in Fig. 23 / Fig. 25 (e.g., a structure in which SSB starts from symbol 2 / 5 / 8 / 11), in the case of 15 kHz SCS (or for commonality, in the case of other SCS), a structure in which SSB starts from symbol 1 / 4 / 8 / 11 within each slot may be introduced.

[0332] Additionally, the information required in the PBCH payload may be different between CD-SSB (abbreviation for cell-defining-SSB, which refers to an SSB that provides a CORESET and search space configuration on which a SIB1 PDCCH that schedules a SIB1 PDSCH can be transmitted) and NCD-SSB (abbreviation for non-cell-defining-SSB, which refers to an SSB that does not provide a CORESET and search space configuration on which a SIB1 PDCCH that schedules a SIB1 PDSCH can be transmitted). For example, CORESET / Type0-PDCCH CSS set information is required through the PBCH in CD-SSB, but such information may not be carried through the PBCH in NCD-SSB. Accordingly, the PBCH resource area constituting the NCD-SSB can be defined smaller than the PBCH resource area constituting the CD-SSB. For example, an SSB burst structure such as FIG. 23 / FIG. 25 can be applied for the CD-SSB, and an SSB burst structure such as FIG. 24 / FIG. 26 can be applied for the NCD-SSB.

[0333] When the SSB burst structure proposed in SSB Example #2 is applied, the UE can assume that SSBs of the structure are transmitted at the default periodicity (the SSB cycle assumed when the UE has not explicitly received SSB periodicity-related information, e.g., 20 msec) upon initial connection. When a specific SSB is detected, the UE can obtain the index of the SSB through the PBCH DM-RS and / or PBCH payload and recognize the slot / symbol index (e.g., defined in the standard) where the index is transmitted, thereby determining the frame boundary.

[0334] [SSB Example #3] Separate operation of SS-burst consisting of PSS / SSS and PBCH-burst consisting of PBCH

[0335] As mentioned above, SS burst / block may mean SS (excluding PBCH), and PBCH burst / block may mean PBCH (excluding SS) structure.

[0336] In this way, in SSB Example #3, a method is proposed to individually operate an SS-burst composed of PSS / SSS, etc. and a PBCH-burst composed of PBCH.

[0337] For example, option 1) can reduce energy consumption of the base station by always transmitting the SS-burst, but transmitting the PBCH-burst only when requested by the terminal (e.g., via PRACH) (conveniently called the on-demand PBCH procedure). Fig. 30 illustrates an example of the on-demand PBCH procedure.

[0338] Alternatively, option 2) the SS burst is transmitted at a relatively short period and the PBCH burst is transmitted at a relatively long period (conveniently referred to as PBCH-burst periodicity adaptation), thereby reducing the energy consumption of the base station. Fig. 31 illustrates an example of PBCH-burst periodicity adaptation. In Fig. 31, the SS burst can be transmitted across two slots, and the period of the PBCH burst can be set to be longer than the period of the SS burst. For example, multiple SS bursts can be transmitted within one PBCH burst period.

[0339] As in SSB Example #1, the sequence of PSS / SSS / PBCH DM-RS and / or PBCH payload configuration and / or time axis position of PSS / SSS / PBCH and / or size of frequency resource occupied by PSS / SSS / PBCH may be different from those defined in the existing 5G NR standard.

[0340] As in Option 1, an SS-burst being always transmitted could mean that all SS blocks that make up the SS burst are always transmitted (always-on), but it could also mean that the SS burst contains at least one always-on SS block.

[0341] As in Option 2, the fact that the PBCH-burst is transmitted only when there is a UE request may mean that the entire SS blocks constituting the PBCH burst are transmitted on-demand by the UE, but it may also mean that the PBCH burst contains at least one on-demand PBCH block.

[0342] As described below, an SS block may be associated with at least one PBCH block, or conversely, a PBCH block may be associated with at least one SS block. The associated SS block and PBCH burst may be related to at least one of the same QCL assumption, the same beam, and / or the same spatial filter.

[0343] The proposed on-demand procedure-based operation is not only applicable to examples where SS burst and PBCH burst are provided separately (in the time domain) (e.g., FIGS. 28 to 31), but can also be applied to the SSB burst structure of the existing NR and / or the SSB burst structure of the SSB examples #1 / 2 above. For example, while maintaining the basic structure and resource allocation form of the SSB burst structure of the existing NR / SSB burst of proposals #1 / #2, the on / off of the PBCH within the SSB burst can be determined depending on whether the UE requests the PBCH. If the PBCH is off / omitted within the SSB burst, it can be referred to as an SS burst. If the PBCH is on / mapped within the SSB burst, it can be interpreted that the SSB burst includes not only the SS burst but also the PBCH burst.

[0344] Fig. 27 is an example for explaining the provision of PBCH within an SSB burst in an on-demand manner. Fig. 27 is a form in which only the PBCH is turned off / omitted from the SSB burst of Fig. 18. That is, Fig. 27 refers to Fig. 18, which is the SSB burst structure of the existing NR, as the simplest example, but when the on-demand PBCH procedure is applied to proposals #1 / #2, an SSB burst in which only the PBCH is turned off / omitted from the SSB bursts of Figs. 19 to 26 described above is provided, and then, based on a terminal request, an SSB burst in a form in which the PBCH is turned on / mapped as shown in Figs. 19 to 26 can be provided.

[0345] Referring to Fig. 27, (if there is no request from the terminal), the PBCH may not be transmitted and only SSBs other than the PBCH may be transmitted. For example, resources for signals / channels for PBCH request purposes may be determined based on information (e.g., cell index) contained in the SS B that is predefined or transmitted. When the base station receives a PBCH request from the terminal through the corresponding resource, the base station may transmit the PBCH for a set period of time starting from a set period of time (as shown in Fig. 18). When the terminal receives only SSBs other than the PBCH, the terminal may transmit signals / channels for PBCH request purposes through the set resource and receive the PBCH after a set period of time to perform the initial access process.

[0346] The operation based on PBCH-burst periodicity adaptation can also be applied to the existing NR SSB burst structure and / or the SSB burst structure proposed in the SSB examples #1 / 2 above. For example, the SS-burst can be transmitted in a first period (e.g., a 20 msec period) and the PBCH-burst can be transmitted in a second period (e.g., a 40 msec period) that is longer than the first period. In a case where both the SS-burst and the PBCH-burst are transmitted (e.g., a common multiple of the first and second periods), the SSB burst can be transmitted as in FIG. 18, and in a case where only the SS-burst is transmitted and the PBCH-burst is not transmitted, the SSB burst can be transmitted as in FIG. 27.

[0347] In this way, the on-demand procedure can be applied to the SSB burst structure of the existing NR and / or the SSB burst structure proposed in the SSB examples #1 / 2 above, but in this case, since the PSS / SSS and PBCH are TDM / FDM within one SSB, even if it is a PBCH-less SSB burst, several symbol gaps (e.g., basic inter-SSB symbol gaps and / or additional symbol gaps due to PBCH less) are generated between SS-bursts. Since it is difficult for the base station to transition to a sleep state due to these symbol gaps alone, it may be efficient to operate the SS-burst and PBCH-burst separately, thereby transmitting only the SS-burst and allowing the base station to operate in energy saving mode. Both the on-demand procedure and the PBCH-burst periodicity adaptation-based operation can be applied to the SSB burst structure proposed below.

[0348] Figure 28 illustrates an example of separately operating SS-burst and PBCH-burst based on proposal #3.

[0349] Referring to Fig. 28, a structure can be introduced in which an SS block corresponding to one beam or SS index is composed of a total of two OFDM symbols. In Fig. 28, for convenience, it is assumed that one SS block is composed of one PSS and one SSS, but it is not limited thereto, and one SS block can be composed of at least one PSS, or at least one SSS, or at least one PSS and at least one SSS. By positioning four SS block indices within one slot, the number of slots that L_max SS blocks span on the time axis can be reduced. Compared to the SSB burst configuration as in Fig. 18, in Fig. 18, the time taken by the base station to transmit L_max SSBs was 4 msec per SSB period, but in Fig. 28, by reducing it to 2 msec or less in L_max SS blocks (SS blocks constituting an SS burst), the energy consumption of the base station can be reduced. Additionally, by leaving some symbols for each slot empty (e.g., symbols between SS blocks #2 and #3 and / or start / end symbols within a slot), there is an advantage in that DL control / data signals / channels or UL control / data signals / channels can be transmitted through those symbols.

[0350] In Fig. 28, a slot structure consisting of 14 symbols is assumed and a structure of 2 empty symbols - 2 SS blocks - 2 empty symbols - 2 SS blocks - 2 empty symbols is considered, but any 6 symbols within the 14 symbols can be configured as empty symbols, more than 4 2-symbol SS blocks can be located within one slot, and it can be extended to a slot structure consisting of a number of symbols different from 14 symbols. In addition, by providing a symbol gap between the PSS and the SSS, a performance improvement effect can be obtained when using the PSS / SSS for carrier frequency offset (CFO). As an example of forming a symbol gap between the PSS and the SSS, the PSS can be located at symbols 2 / 3 / 8 / 9, and the SSS corresponding to symbols 4 / 5 / 10 / 11 can be located, respectively. When forming a symbol gap between PSS and SSS, the SS block may be composed of PSS(s) or may be composed of SSS(s), and a PSS block and an SSS block may form a pair and be linked to (at least) one PBCH block.

[0351] In Fig. 28, a PBCH burst can be transmitted separately from an SS burst (on-demand), and for convenience, it is assumed that a PBCH burst includes 8 PBCH blocks.

[0352] As explained in the above SSB examples #1-2, there is a trade-off relationship between the base station's energy saving reduction effect and multiplexing efficiency. Considering this, a method of pre-configuring N_max candidate SS blocks, which is more than L_max, and limiting the transmission of up to L_max SS blocks can also be applied to the SSB burst structure based on the SSB example #3. Specifically, as shown in FIG. 29, an SS-burst can be configured without a symbol gap between SS blocks, but up to N_max (14 in the example) candidate SS blocks can be allowed in total. In this state, the base station can select up to L_max SS blocks among the N_max candidate SS blocks for transmission. For example, if SS block indexes 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 are selected, the base station's energy saving effect can be obtained, and if SS block indexes 2 / 3 / 5 / 6 / 9 / 10 / 12 / 13 are selected, the multiplexing efficiency can be improved similarly to FIG. 28.

[0353] Although Fig. 29 assumes a slot structure consisting of 14 symbols, it can be extended to slot structures consisting of a different number of symbols than 14. Furthermore, although the starting position of the SS burst is proposed as the first symbol of slot n, it can also be extended to a method of starting from any arbitrary symbol.

[0354] Even if the SS blocks constituting the SS-burst exist up to N_max indices, the PBCH index constituting the corresponding PBCH-burst can be limited to L_max. This is because only up to L_max SS blocks are transmitted, so the PBCH constituting the PBCH-burst can also operate even if only the up to L_max number of PBCH blocks exist. In Fig. 29, the PBCH burst can be transmitted separately from the SS burst (on-demand), and for convenience, it is assumed that L_max is 8, that is, the PBCH burst includes 8 PBCH blocks.

[0355] In a method such as that of FIG. 28 or FIG. 29, a performance improvement effect can be obtained when using a carrier frequency offset (CFO) using a PBCH DM-RS by providing a symbol / slot gap within the time domain constituting one PBCH index. For example, PBCH index k can be positioned at symbol n / n+2, and PBCH index k+1 can be positioned at symbol n+1 / n+3. Symbol / slot gaps can also be applied between PBCH indices. In order to match the number of RBs allocated for the PBCH to a similar level as the PBCH of FIG. 18, the total number of RBs in the PBCH-burst can be increased to 20 or more.

[0356] Conversely, instead of reducing the number of RBs allocated for the PBCH (e.g., reducing the total number of RBs in a PBCH burst to less than 20), an approach could be used to increase the number of symbols spanned by the PBCH burst (or the number of symbols per PBCH block).

[0357] Additionally, PBCH repetition may be introduced to improve PBCH performance and reliability. For example, each PBCH block within a PBCH burst may be repeated R (>1) times. For example, within a PBCH burst, PBCH block #1 may be mapped R times, and PBCH block #2 may be mapped R times. Alternatively, R blocks for each PBCH block index may be interleaved.

[0358] Currently, NR's PSS / SSS only includes cell index information. However, by operating the PBCH burst separately, additional information may need to be included in the SS block. Specifically, some or all of the following information may be signaled via a separate signal / channel composed of SSS (and / or PSS) and FDM (and / or TDM) (or by utilizing the PSS / SSS sequence).

[0359] - Index of each SS block: When a (PBCH-less) SS-burst is configured as above, it may be difficult for the UE to know the index of each SS block. The SS block index may be needed for purposes such as obtaining a frame boundary, obtaining the QCL relationship between the SS block index and the PBCH index, determining the resources of the on-demand PBCH request signal / channel corresponding to the SS block index, or finding the location of the PBCH index from a specific SS block index.

[0360] - In which order the SS block is transmitted: As shown in FIG. 29, candidate SS block indices may exist up to N_max, but additional signaling may be required to know the corresponding PBCH index (PBCH block index). For example, if SS block index 2 transmitted through symbol 2 / 3 in slot n in FIG. 29 is actually the SS block that the base station is transmitting for the first time in the SS-burst, the base station can signal that SS block index 2 is the first transmitted SS block. The terminal receiving the signaling can recognize that PBCH index 1 is linked to SS block index 2 (i.e., QCL relationship). The signaling can also be introduced when SS block indices exist up to L_max, as shown in FIG. 28. In this case, the base station may signal a number less than L_max (=K, K <L_max)의 SS block들을 전송 중이라면 L_max개가 아닌 K개의 PBCH 블록들만으로 PBCH burst를 구성할 수 있으므로, PBCH-burst를 전송하는 에너지 소모를 줄일 수 있다. 혹은, 해당 SS block index와 링크된 PBCH index를 시그널링 할 수 있다. 일 예로, SS block index n으로부터, 해당 값이 m이라고 시그널링 받은 단말은, 해당 SS block index n과 링크된 PBCH index는 m임을 인지할 수 있다.

[0361] - PBCH-burst location information: When the location of the PBCH-burst can be determined relatively from the location of the SS-burst or absolutely by utilizing a frame boundary, etc., as described below, the necessary parameters can be signaled.

[0362] - Information about the resources of a signal / channel (e.g., PRACH) for a PBCH-burst request: Some or all of the information configuring the resources of the signal / channel may be signaled. For convenience, we assume requests are made in PBCH burst units, but requests may also be made in PBCH block units.

[0363] - Information about PBCH-burst transmission: (In case of on-demand procedure-based operation) whether PBCH-burst is being transmitted (e.g., whether PBCH-burst transmission is enabled) can be signaled. If the UE receives signaling that it is not transmitting, it can expect PBCH reception by transmitting a signal / channel for PBCH-burst request, and if it receives signaling that it is transmitting, it can expect PBCH reception at the defined / signaled PBCH-burst position. Alternatively, if the UE receives signaling that it is not transmitting, it can not expect PBCH reception at the PBCH-burst position (additionally, it can attempt detection / (re)selection for other cells), and if it receives signaling that it is transmitting, it can expect PBCH reception at the defined / signaled PBCH-burst position. In the case of on-demand procedure-based operation, the time period (and periodicity) during which the PBCH will be transmitted after a PBCH-burst request can be signaled. After transmitting the signal / channel for the PBCH-burst request, the UE can expect that the PBCH will be transmitted by the base station during the corresponding time period (and periodicity) from a predetermined time point. Information about the transmission pattern (e.g., periodicity, offset, etc.) of the currently transmitting PBCH-burst can be signaled. For example, in the case of PBCH-burst periodicity adaptation-based operation, the PBCH-burst periodicity can be signaled in terms of how large (or small) it is compared to the SS-burst periodicity, or the period (and / or offset) value. In addition, in the case of a NCD (non-cell defining)-SS Block, it can be signaled that the PBCH-burst is not transmitted (or that it is an NCD-SS Block).When it is signaled that it is an NCD-SS Block, the terminal may recognize that the amount of time / frequency resources corresponding to each PBCH index is different depending on whether it is an NCD-SS Block or a CD (cell defining)-SS Block, or it may recognize that there is no PBCH burst if it is an NCD-SS Block and that there is a PBCH burst if it is a CD-SS Block. In this case, it can be signaled to distinguish whether the PBCH burst is not transmitted due to an NCD-SSB or because it was not triggered through a PBCH burst request.

[0364] - Flag bit(s) indicating whether cell barring is present: The terminal can quickly determine whether cell barring is present by receiving only SS-burst.

[0365] - Power offset between SS-burst and PBCH-burst: The power offset value can be predefined or explicitly signaled through the SS-burst. In addition, the power offset between the PSS / SSS constituting the SS-burst and "a separate signal / channel that is FDM (and / or TDM) with the SSS (and / or PSS)" can be predefined. The power offset here can mean EPRE (energy per resource element).

[0366] SS-burst and PBCH-burst can be transmitted in TDM / FDM, and the location of the PBCH-burst can be determined relatively from the location of the SS-burst (e.g., Opt 1) or absolutely using frame boundaries, etc. (e.g., Opt 2). The PBCH-burst location information can be applied to both on-demand procedure-based and PBCH-burst periodicity adaptation-based operations.

[0367] 1) Opt 1 (the position of the PBCH-burst is determined relatively from the position of the SS-burst): The time offset value from a specific (e.g., lowest) index (start) symbol position of the SS-burst to a specific (e.g., lowest) index (start) symbol position of the PBCH-burst may be predefined or signaled from the base station. For example, in an SSB burst structure such as FIG. 28, a terminal that detects SS block index 4 can identify the position of SS block index 1, and after identifying the starting symbol position of PBCH index 1 by applying the time offset value from the corresponding SS block index 1, recognize the position of the corresponding PBCH index 4, and receive PBCH index 4, which is in a QCL relationship with SS block index 4. Alternatively, the time offset value between SS block index m and PBCH index n may be predefined (in this case, m may be n) or signaled from the base station.

[0368] 2) Opt 2 (the position of the PBCH-burst is absolutely determined using frame boundary, etc.): The time offset value from the frame boundary to which a specific (eg, lowest) index of the SS-burst belongs to the position of a specific (eg, lowest) index (start) symbol of the PBCH-burst (or the frame boundary to which the specific (eg, lowest) index PBCH belongs) can be defined in advance or signaled from the base station.

[0369] Meanwhile, if N_max candidate SS Blocks are set / defined, which is more than L_max, at least one of the following may need to be additionally considered.

[0370] - The amount of information indicating the actual transmitted SS block index can be increased through cell-specific higher layer signaling such as SIB and / or UE-specific higher layer signaling. For example, if N_max is 14, the actual transmitted SS block index can be indicated through a 14-bit bitmap (where the lowest / highest SS block index can be mapped to the LSB and the highest / lowest SS block index can be mapped to the MSB), and the maximum number of SS block indices for which '1' is signaled through the 14-bit bitmap can be limited to L_max.

[0371] - When the terminal receives a PDSCH including SIB1 (or receives the PDSCH before receiving signaling about which SS block among N_max SS block indices is actually transmitted), since it may not know which SS block among N_max SS block indices is actually transmitted, the terminal may receive the PDSCH assuming that all N_max candidate SS block resources are not available. In addition, the terminal may receive the PDSCH assuming that all L_max PBCH-burst resources are not available, or if the terminal recognizes that a PBCH-burst is transmitted based on signaling from the SS-burst, the terminal may receive the PDSCH assuming that the PBCH-burst resource is not available, and if the terminal recognizes that the PBCH-burst is not transmitted, the terminal may receive the PDSCH assuming that the PBCH-burst resource is available.

[0372] For example, the SS block index(es) actually transmitted can be signaled via cell-specific higher layer signaling such as SIB and / or UE-specific higher layer signaling. If L_max candidate SS blocks are defined as in FIG. 28, the corresponding information can be signaled via the L_max-bitmap. If the value corresponding to the k-th bit of L_max is '1', the UE can recognize that the transmission is for the k-th SS block index and PBCH index, and can assume that the resource corresponding to the SS block index and PBCH index (or the entire slot including the resource) is not available for DL ​​signal reception (other than the SS block) or that UL signal transmission is not performed (including the preceding / successive resources of the resource).

[0373] When N_max candidate SS blocks are defined as in Fig. 29, the corresponding information can be signaled through the N_max-bitmap. If the value corresponding to the kth bit of N_max is '1' and the '1' is the nth '1' in the bitmap information, the terminal can recognize that the transmission is for the kth SS block index and the nth PBCH index (not the kth), and can assume that the resource corresponding to the SS block index and PBCH index (or the entire slot including the resource) is not available for DL ​​signal reception (not the SS block) or that UL signal transmission (including the preceding / successive resources of the resource) is not performed. For example, when N_max=14 and the bitmap information is '1010 1100 0000 00', if k=3 (since the '1' corresponding to k=3 is the second '1' in the bitmap information), n=2.

[0374] Even if L_max candidate SS blocks are defined as in Fig. 28, if the base station has a number less than L_max (=K, K <L_max)의 SS block들을 전송 중이라면 L_max개가 아닌 K개의 PBCH들만으로 PBCH burst를 구성한다면 도 29과 유사한 방법이 적용될 수 있다. 예를 들어, L_max-bitmap을 통해 실제 전송되는 SS block index(들)의 정보가 시그널링될 수 있다. 이 때, L_max의 k번째 bit에 대응되는 값이 '1'이고 해당 '1'이 bitmap 정보에서 n번째 '1'이면 k번째 SS block index및 (k번째가 아닌) n번째 PBCH index에 대해 전송임을 단말은 인지할 수 있고, 해당 SS block index 및 PBCH index에 대응되는 자원(혹은 해당 자원이 포함된 slot 전체)에 대해 (SSB가 아닌) DL 신호 수신을 위해 available하지 않다고 가정하거나 (해당 자원의 선행 / 후행 자원을 포함하여) UL 신호 전송을 수행하지 않는다고 가정할 수 있다.

[0375] Meanwhile, considering a frame structure in which the CP length changes every 0.5 msec, it may not be desirable in terms of the implementation complexity of the terminal attempting the initial access to have a symbol with a different CP located in the middle of an SS block (or PBCH). To this end, in the SS burst structure as in Fig. 29, in the case of 15 kHz SCS (or other SCS for commonality), a structure may be introduced in which no SS block is defined for symbol 6 / 7 within each slot, or 6 SS blocks are defined within each slot, and each SS block starts from symbol 1 / 3 / 5 / 8 / 10 / 12 (or symbol 1 / 3 / 5 / 7 / 9 / 11). In addition, in the case of the PBCH constituting the PBCH-burst, it may be designed so that the CP does not change in the middle of the symbols corresponding to a single PBCH index.

[0376] In addition, the information required in the PBCH payload may be different for each of the CD-SS block and the NCD-SS block. For example, while CORESET / Type0-PDCCH CSS set information is required for the PBCH related to the CD-SS block, the information may not need to be carried for the PBCH related to the NCD-SS block. Therefore, the PBCH resource area related to the NCD-SS block can be defined smaller than the PBCH resource area related to the CD-SS block. For example, the PBCH of the PBCH-burst related to the CD-SS block can be configured with 2 symbols for each index, and the PBCH of the PBCH-burst related to the NCD-SS block can be configured with 1 symbol for each index.

[0377] When providing CORESET information through PBCH, multiplexing pattern information between SSB and CORESET may be included. Here, the TDM / FDM pattern between SSB and CORESET may refer to the multiplexing pattern between PBCH-burst and CORESET. That is, FDM may refer to X PRBs (the corresponding X value may be defined in advance or signaled through PBCH) starting from the point where the frequency axis offset is applied based on a specific RE / RB of PBCH index n as a resource of CORESET linked to the corresponding PBCH index n.

[0378] When SSB Example #3 is applied, the terminal can assume that SS-bursts of the corresponding structure are transmitted at the default periodicity (the SS block period assumed when the terminal has not explicitly received SS block periodicity-related information, e.g., 20 msec) upon initial connection. The terminal can obtain the index of the corresponding SS block by receiving the SS-burst and recognize the slot / symbol index (i.e., defined in the specification) where the corresponding index is transmitted, thereby determining the frame boundary. In the case of on-demand procedure-based operation, the terminal can obtain the signal / channel resources for requesting an on-demand PBCH based on the SS-burst and / or predefined information. After transmitting the signal / channel for the PBCH-burst request, the terminal can receive the PBCH for the corresponding time interval (at the corresponding period) from a predetermined time point. In the case of PBCH-burst periodicity adaptation-based operation, the terminal can obtain the resource information of the PBCH-burst based on the SS-burst and / or predefined information. The terminal can receive the PBCH from the corresponding resource. Thereafter, the terminal can obtain additional timing information and information required for SIB1 reception through the PBCH DM-RS and / or PBCH payload.

[0379] Next, we propose an adaptive SS block / burst transmission that can be applied in various environments, including the environments to which the above-described SSB examples apply.

[0380] When a combination of specific SSB (or SS block) index(es) is fixedly transmitted, there is a disadvantage that the benefit may be biased toward either energy saving of the base station or increased multiplexing efficiency. For example, in the example described through FIG. 21, if Opt1) SSB index 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 is selected and transmitted, the base station energy saving effect can be obtained, and if Opt2) SSB index 1 / 3 / 4 / 6 / 7 / 9 / A / C is selected and transmitted, the multiplexing efficiency with other potentially transmittable channels can be improved. If the number of terminals currently connected to the base station is small, it may be advantageous to operate SSB like Opt 1 for energy saving effect, and conversely, it may be advantageous to operate SSB like Opt 2 considering multiplexing efficiency.

[0381] Therefore, we would like to propose a method for adapting SSB indices (or SS block indices or PBCH-burst indices) that constitute an SSB burst (or SS-burst or PBCH-burst) and a specific signaling method.

[0382] [Proposal #1] Signaling of SSB indices (or SS block indices or PBCH-burst indices) that constitute an SSB burst (or SS-burst or PBCH-burst).

[0383] When a set of SSB indices (or SS block indices or PBCH burst indices) that constitute one SSB burst (or SS-burst or PBCH-burst) is called a pattern, one or more such patterns can be defined / set. In this specification, the term "pattern" can be expressed / replaced with other terms including "configuration", "indication", "mode", "sub-configuration", "subset", "selection", "mask", or "sub-sampling".

[0384] For example, the network can set / instruct the terminal to set / instruct the pattern index value to be applied. For example, if pattern 1 is composed of SSB index 1 / 2 / 3 / 4 and pattern 2 is composed of SSB index 2 / 4 / 6 / 8, and it is defined / set in advance, then SSB index adaptation that configures SSB can be performed by signaling (e.g., directly using the pattern index) which pattern among pattern 1 or pattern 2 is to be applied. When the terminal receives signaling for pattern 1, it can assume that an SSB burst composed of SSB index 1 / 2 / 3 / 4 is transmitted from the base station, and when it receives signaling for pattern 2, it can assume that an SSB burst composed of SSB index 2 / 4 / 6 / 8 is transmitted from the base station.

[0385] In this specification, the SSB index can be replaced with the SS block index, and the proposed methods can be applied even when there are two or more patterns. Furthermore, in this specification, the number of SSB indices constituting one SSB burst may be the same or different for each pattern.

[0386] Alternatively, the SSB index (or SS block index or PBCH-burst index)(s) corresponding to each pattern can be directly signaled. For example, when the base station determines that pattern 1 is composed of SSB index 1 / 2 / 3 / 4 and pattern 2 is composed of SSB index 2 / 4 / 6 / 8, SSB index adaptation constituting the SSB can be performed by signaling the SSB index(es) constituting each pattern. Specifically, by signaling '11110000' for the bitmap information composed of the entire 8-bit, the base station can inform the terminal that it is pattern 1, and by signaling '01010101', the base station can inform the terminal that it is pattern 2. When the terminal receives signaling for pattern 1 (e.g., bitmap information of '11110000'), it can assume that an SSB burst composed of SSB indices 1 / 2 / 3 / 4 is transmitted from the base station, and when it receives signaling for pattern 2 (e.g., bitmap information of '01010101'), it can assume that an SSB burst composed of SSB indices 2 / 4 / 6 / 8 is transmitted from the base station. The SSB index corresponding to each bit constituting the bitmap can be a single SSB index or can be one or more SSB indices. The mapping method can be defined in advance, or the mapping relationship can be set in advance (by RRC signaling).

[0387] The above pattern index signaling or SSB index signaling can be transmitted through all or part of the following methods.

[0388] - (UE group-common or UE-specific or broadcast or multicast) DCI: For example, the signaling may be transmitted in DCI for scheduling system information (e.g., scrambled with SI-RNTI). Or the signaling may be transmitted in DCI for scheduling paging (or paging-related) messages (e.g., scrambled with P-RNTI or PEI-RNTI). Or the signaling may be transmitted in DCI transmitted during a random access procedure (e.g., scrambled with RA-RNTI or TC-RNTI). Or the signaling may be transmitted in DCI for scheduling UE-specific data (e.g., scrambled with C-RNTI).

[0389] - (UE group-common or UE-specific or broadcast or multicast) PDSCH: For example, the signaling may be transmitted through a PDSCH carrying cell-specific higher layer signaling such as SIB. Or the signaling may be transmitted through a PDSCH carrying a paging message. Or the signaling may be transmitted through a PDSCH transmitted during a random access procedure. Or the signaling may be transmitted through a PDSCH carrying UE-specific higher layer signaling (or MAC-CE or DL-SCH).

[0390] In the above pattern index signaling or SSB index signaling, the serving cell / carrier / BWP through which the DL signal / channel including the signaling is transmitted and the serving cell / carrier / BWP through which the SSB burst to which the signaling is applied is transmitted may be the same or different. In different cases, the SSB burst to which the signaling is applied may be transmitted on a non-serving cell or a neighboring cell or a different carrier within the same serving cell or a different BWP within the same serving cell. In addition, the DL signal / channel including the signaling may include pattern index or SSB index signaling (for each or a common SSB burst) for SSB burst(s) transmitted on one or more serving cells / carriers / BWPs.

[0391] An agreement may be required between the UE and the eNB regarding the distance from the time point (T1) when the DL signal / channel including the pattern index signaling or SSB index signaling as described above is transmitted to the time point when the first SSB burst to which the signaling is applied is received. T1 may be the start / end boundary of the symbol / CORESET / slot / subframe / half-frame / frame that includes the DL signal / channel, and the transmission of the SSB burst to which the signaling is applied may start from the first SSB burst transmission occasion after X symbols / slots / msec / subframes / half-frames / frames from T1. Here, the value of X may be predefined or may be a value set by the eNB. For example, when there is an SSB burst transmitted when SFN (system frame number) mod 4 = 0, it is assumed (from the perspective of the UE that received the SSB burst to which pattern 1 is applied at SFN index 0) that the DL signal / channel was received by the UE in a specific slot n belonging to SFN index 2, and the DL signal / channel indicated pattern 2. If X=2 slots, the terminal can assume that pattern 2 is applied from the SSB burst transmitted at SFN index 4, which is the first SSB burst transmission occasion after slot n+2.

[0392] As another example, cell DTX operation and SSB burst pattern can be operated in conjunction.

[0393] For example, SSB burst pattern a may be applied during a specific cell DTX active period, and SSB burst pattern b may be applied during a non-active period. The SSB burst pattern applied to each period may be predefined or configured by the base station. The terminal may assume that after cell DTX configuration and / or activation through DCI, an SSB burst corresponding to SSB burst pattern a is transmitted during the active period, and SSB burst pattern b is transmitted during the non-active period. Alternatively, when multiple cell DTX patterns can be configured, the SSB burst pattern for each pattern may be linked and operated.

[0394] For example, SSB burst pattern c may be linked to cell DTX pattern 1, and SSB burst pattern d may be linked to cell DTX pattern 2. The SSB burst pattern applied to each cell DTX pattern may be predefined or configured by the base station. The terminal may assume that after cell DTX pattern 1 is configured and / or activated via DCI, an SSB burst corresponding to SSB burst pattern c is transmitted (during an active period), and after cell DTX pattern 2 is configured and / or activated via DCI, an SSB burst corresponding to SSB burst pattern d is transmitted (during an active period).

[0395] The base station can also configure cell barring for each terminal differently depending on the SSB burst pattern. For example, when SSB burst pattern 1 is applied, the base station operates in a mode that maximizes energy savings, so cell barring can be configured / signaled to prevent terminals without operating capabilities for this mode (or NES mode) from accessing the cell. Conversely, when SSB burst pattern 2 is applied, the base station operates in a mode that maximizes multiplexing efficiency, so cell barring can be not configured / signaled in this mode (or non-NES mode).

[0396] [Proposal #2] A specific embodiment and QCL assumption method for adapting the SSB indices (or SS block indices or PBCH-burst indices) that constitute an SSB burst (or SS-burst or PBCH-burst).

[0397] Next, for the SSB burst structures in SSB examples #1 / 2 / 3, we propose examples of operating the SSB burst pattern differently, and propose a method for the terminal to assume QCL between SSB indices according to the pattern.

[0398] [QCL method #1] When changing from pattern a to pattern b, the QCL relationship is maintained between the SSB index(es) belonging to pattern a and the same SSB index(es) (belonging to pattern b), and for the remaining SSB index(es), the QCL relationship may be the same in the order of the index (e.g., ascending / descending), or the QCL relationship may not be assumed.

[0399] For example, when changing from pattern 1 to pattern 2, it is assumed that SSB indexes belonging to pattern 1 are 1 / 2 / 3 / 4 and SSB indexes belonging to pattern 2 are 2 / 4 / 6 / 8. The terminal can assume that the common index SSB index 2 / 4 maintains the QCL relationship. For example, the terminal can assume that SSB index 2 (or SSB index 4) of SSB burst pattern 1 and SSB index 2 (or SSB index 4) of SSB burst pattern 2 are in a QCL relationship. The terminal can assume that non-common indexes, for example, SSB indexes 1 / 3 of pattern 1 and SSB indexes 6 / 8 of pattern 2, are in a QCL relationship in the order of the indexes (Alt-1) or that there is no QCL relationship (Alt-2). For Alt-1, the terminal can assume that SSB index 1 (or SSB index 3) of SSB burst pattern 1 and SSB index 6 (or SSB index 8) of SSB burst pattern 2 are in a QCL relationship. If SSB index X belonging to pattern a and SSB index Y belonging to pattern b are in a QCL relationship, it may mean that combining and / or measurement using SSB index X and SSB index Y together is possible. Conversely, if there is no QCL relationship between SSB index X belonging to pattern a and SSB index Y belonging to pattern b, it may mean that combining and / or measurement using SSB index X and SSB index Y together is not possible.

[0400] [QCL method #2] When changing from pattern a to pattern b, the QCL relationship may be the same in terms of the index order (e.g., ascending / descending order) between the SSB index(es) belonging to pattern a and the SSB index(es) belonging to pattern b, or the QCL relationship may not be assumed.

[0401] For example, when changing from pattern 1 to pattern 2, it is assumed that the SSB indexes belonging to pattern 1 are 1 / 2 / 3 / 4 and the SSB indexes belonging to pattern 2 are 2 / 4 / 6 / 8. At this time, the terminal can assume that the SSB indexes 1 / 2 / 3 / 4 belonging to pattern 1 and the SSB indexes 2 / 4 / 6 / 8 belonging to pattern 2 are in a QCL relationship in the order of the indexes (Alt-1), or the terminal can assume that there is no QCL relationship (Alt-2). In the case of Alt-1, the terminal can assume that the SSB index 1 (or SSB index 2 / 3 / 4) of SSB burst pattern 1 and the SSB index 2 (or SSB index 4 / 6 / 8) of SSB burst pattern 2 are in a QCL relationship (respectively in order). If SSB index X belonging to pattern a and SSB index Y belonging to pattern b have a QCL relationship, it may mean that combining and / or measurement using SSB index X and SSB index Y together is possible. Conversely, if there is no QCL relationship between SSB index X belonging to pattern a and SSB index Y belonging to pattern b, it may mean that combining and / or measurement using SSB index X and SSB index Y together is not possible.

[0402] <SSB 예시#1을 활용한 SSB burst pattern >

[0403] For example, referring to Fig. 22, assume Pattern 1 and Pattern 2 as follows.

[0404] - Pattern 1 (e.g., for base station energy saving): SSB index 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 of Fig. 22

[0405] - Pattern 2 (e.g., to increase multiplexing efficiency): SSB index 1 / 3 / 5 / 7 / 8 / A / C / E of Fig. 22

[0406] When changing from Pattern 1 to Pattern 2:

[0407] - Application of QCL method #1: The terminal can assume that SSB index 1 (or SSB index 3 / 5 / 7 / 8) of SSB burst pattern 1 and SSB index 1 (or SSB index 3 / 5 / 7 / 8) of SSB burst pattern 2 are in a QCL relationship. For non-common indices, for example, SSB indexes 2 / 4 / 6 of pattern 1 and SSB indexes A / C / E of pattern 2, the terminal can assume that (Alt-1) they are in a QCL relationship in the order of the indexes, or (Alt-2) they have no QCL relationship. In the case of Alt-1, the terminal can assume that SSB index 2 (or SSB index 4 / 6) of SSB burst pattern 1 and SSB index A (or SSB index C / E) of SSB burst pattern 2 are in a QCL relationship.

[0408] - Application of QCL method #2: The terminal can assume that SSB indexes 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 belonging to SSB burst pattern 1 and SSB indexes 1 / 3 / 5 / 7 / 8 / A / C / E belonging to SSB burst pattern 2 are in a QCL relationship in the respective index order (Alt-1), or the terminal can assume that there is no QCL relationship (Alt-2). In the case of Alt-1, the terminal can assume that SSB index 1 (or SSB index 2 / 3 / 4 / 5 / 6 / 7 / 8) of SSB burst pattern 1 and SSB index 1 (or SSB index 3 / 5 / 7 / 8 / A / C / E) of SSB burst pattern 2 are in a QCL relationship (respectively in that order).

[0409] <SSB 예시#2를 활용한 SSB burst pattern>

[0410] For example, referring to Figure 25, assume Pattern 1 and Pattern 2 as follows.

[0411] - Pattern 1 (e.g., for base station energy saving): SSB index 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 of Fig. 25

[0412] - Pattern 2 (e.g., to increase multiplexing efficiency): SSB index 1 / 3 / 5 / 7 / 9 / B / D / F of Fig. 25

[0413] When changing from Pattern 1 to Pattern 2:

[0414] - Application of QCL method #1: The terminal can assume that SSB index 1 (or SSB index 3 / 5 / 7) of SSB burst pattern 1 and SSB index 1 (or SSB index 3 / 5 / 7) of SSB burst pattern 2 are in a QCL relationship. For non-common indices, for example, SSB indexes 2 / 4 / 6 / 8 of pattern 1 and SSB indexes 9 / B / D / F of pattern 2, the terminal can assume that (Alt-1) they are in a QCL relationship in the order of the indexes, or (Alt-2) they have no QCL relationship. In the case of Alt-1, the terminal can assume that SSB index 2 (or SSB index 4 / 6 / 8) of SSB burst pattern 1 and SSB index 9 (or SSB index B / D / F) of SSB burst pattern 2 are in a QCL relationship.

[0415] - Application of QCL method #2: The terminal can assume that SSB indexes 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 belonging to SSB burst pattern 1 and SSB indexes 1 / 3 / 5 / 7 / 9 / B / D / F belonging to SSB burst pattern 2 are in a QCL relationship in the order of the indexes (Alt-1), or the terminal can assume that there is no QCL relationship (Alt-2). In the case of Alt-1, the terminal can assume that SSB index 1 (or SSB index 2 / 3 / 4 / 5 / 6 / 7 / 8) of SSB burst pattern 1 and SSB index 1 (or SSB index 3 / 5 / 7 / 9 / B / D / F) of SSB burst pattern 2 are in a QCL relationship (respectively in order).

[0416] <SSB 예시#3을 활용한 SSB burst pattern >

[0417] For example, referring to Fig. 29, assume Pattern 1 and Pattern 2 as follows.

[0418] - Pattern 1 (e.g., for base station energy saving): SSB index 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 of Fig. 29

[0419] - Pattern 2 (e.g., to increase multiplexing efficiency): SSB index 2 / 3 / 5 / 6 / 9 / 10 / 12 / 13 of Figure 29

[0420] When changing from Pattern 1 to Pattern 2:

[0421] - Application of QCL method #1: The terminal can assume that SSB index 2 (or SSB index 3 / 5 / 6) of SSB burst pattern 1 and SSB index 2 (or SSB index 3 / 5 / 6) of SSB burst pattern 2 are in a QCL relationship. For non-common indices, for example, SSB indexes 1 / 4 / 7 / 8 of pattern 1 and SSB indexes 9 / 10 / 12 / 13 of pattern 2, the terminal can assume that (Alt-1) they are in a QCL relationship in the order of the indexes, or (Alt-2) they have no QCL relationship. In the case of Alt-1, the terminal can assume that SSB index 1 (or SSB index 4 / 7 / 8) of SSB burst pattern 1 and SSB index 9 (or SSB index 10 / 12 / 13) of SSB burst pattern 2 are in a QCL relationship. In this case, only the common SS block index maintains the link relationship with the PBCH index, and the remaining SS block indices can be mapped to the PBCH index in order. For example, in case of SSB burst pattern 1, SS block index 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 and PBCH index 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 are linked in order, respectively (for example, it is assumed by the terminal that the corresponding SS block and the corresponding PBCH (block) are in a QCL relationship), and in case of SSB burst pattern 2, SS-burst 2 / 3 / 5 / 6 / 9 / 10 / 12 / 13 and PBCH index 2 / 3 / 5 / 6 / 1 / 4 / 7 / 8 can be linked in order, respectively (for example, it can be assumed by the terminal that they are in a QCL relationship).

[0422] - Application of QCL method #2: The terminal can assume that SSB indexes 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 belonging to SSB burst pattern 1 and SSB indexes 2 / 3 / 5 / 6 / 9 / 10 / 12 / 13 belonging to SSB burst pattern 2 are in a QCL relationship in the respective index order (Alt-1), or the terminal can assume that there is no QCL relationship (Alt-2). In the case of Alt-1, the terminal can assume that SSB index 1 (or SSB index 2 / 3 / 4 / 5 / 6 / 7 / 8) of SSB burst pattern 1 and SSB index 2 (or SSB index 3 / 5 / 6 / 9 / 10 / 12 / 13) of SSB burst pattern 2 are in a QCL relationship (respectively in the respective order). In this case, the SS block indexes belonging to each SSB burst pattern can be mapped to the PBCH index in the respective order. For SSB burst pattern 1, SS block index 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 and PBCH index 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 are linked in order, respectively (e.g., it is assumed by the terminal that they are in a QCL relationship), and for SSB burst pattern 2, SS-burst 2 / 3 / 5 / 6 / 9 / 10 / 12 / 13 and PBCH index 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 can be linked in order, respectively (e.g., it is assumed by the terminal that they are in a QCL relationship).

[0423] At this time, the relative position of the PBCH-burst compared to the SS-burst can be set / defined differently for each pattern.

[0424] Figure 32 illustrates the operation of a terminal and a base station according to one embodiment.

[0425] Referring to FIG. 32, as in Proposal #1, the base station can set at least two SSB burst patterns and set the SSB index(es) that constitutes the SSB burst for each pattern (A05). In addition, the base station can signal that the set Pattern 1 will be used.

[0426] The terminal can receive the SSB burst assuming that the SSB index(es) corresponding to the pattern 1 is included in the SSB burst (A10).

[0427] The base station may transmit signaling indicating a change to pattern 2 (A15).

[0428] A terminal receiving the signaling can receive the SSB burst, assuming that the SSB index(es) corresponding to pattern 2 is included in the SSB burst (A20). At this time, as proposed in Proposal #2, the terminal can perform combining and / or measurement between SSB indices by utilizing the QCL relationship between different patterns.

[0429] According to the present disclosure, a setting method, a signaling method, and a QCL method are supported to support switching between an SSB burst pattern for energy saving of a base station and an SSB burst pattern for efficient communication, thereby enabling a base station to perform SSB burst transmission suitable for a specific situation.

[0430] Figure 33 illustrates a flowchart of a method performed by a terminal according to one embodiment. Figure 33 is an implementation example of at least some of the above-described proposals, and reference may be made to the previously described content unless otherwise stated.

[0431] Referring to FIG. 33, the terminal can receive information about switching from a first pattern to a second pattern among a plurality of patterns related to transmission of a burst including a plurality of SS (synchronization signal) blocks (B05).

[0432] The terminal can receive at least one second SS block among a plurality of second SS blocks belonging to a second burst related to the second pattern (B10).

[0433] The terminal may receive at least one second SS block based on quasi co-location (QCL) information. For example, the terminal may obtain quasi co-location (QCL) information for at least one second SS block based on at least one first SS block among a plurality of first SS blocks belonging to a first burst related to the first pattern.

[0434] The terminal can determine at least one first SS block to provide the QCL information to at least one second SS block based on the linkage between the plurality of first SS blocks and the plurality of second SS blocks.

[0435] The linkage between the plurality of first SS blocks and the plurality of second SS blocks may include a mapping between indices of the plurality of first SS blocks and indices of the plurality of second SS blocks.

[0436] Based on the fact that the SS block index within the first burst matches the SS block index within the second burst, the terminal can determine that the first SS block and the second SS block have a QCL relationship.

[0437] The terminal can determine that the plurality of first SS blocks sorted in SS block index order within the first burst have a QCL relationship with the plurality of second SS blocks sorted in SS block index order within the second burst.

[0438] Information about the above switching may include information about the index of the second pattern or the configuration of the second burst related to the second pattern.

[0439] Information about the configuration of the second burst may include information about indices of the plurality of second SS blocks transmitted within the second burst.

[0440] Information about the above switching can be received via downlink control information (DCI) or a physical downlink shared channel (PDSCH) scheduled by the DCI.

[0441] A first time length from the leading first SS block to the last first SS block within the first burst may be different from a second time length from the leading second SS block to the last second SS block within the second burst.

[0442] A first time gap between the plurality of first SS blocks within the first burst may be different from a second time gap between the plurality of second SS blocks within the second burst.

[0443] Figure 34 illustrates a flowchart of a method performed by a base station according to one embodiment. Figure 34 is an implementation example of at least some of the above-described proposals, and reference may be made to the previously described content unless otherwise stated.

[0444] Referring to FIG. 34, a base station can transmit information about switching from a first pattern to a second pattern among a plurality of patterns related to transmission of a burst including a plurality of synchronization signal (SS) blocks (C05).

[0445] The base station can transmit at least one second SS block among a plurality of second SS blocks belonging to a second burst related to the second pattern (C10).

[0446] At least one first SS block among the plurality of first SS blocks belonging to the first burst related to the first pattern may have a QCL (quasi co-location) relationship with the at least one second SS block.

[0447] At least one first SS block having a QCL relationship with at least one second SS block can be determined based on the linkage between the plurality of first SS blocks and the plurality of second SS blocks.

[0448] The linkage between the plurality of first SS blocks and the plurality of second SS blocks may include a mapping between indices of the plurality of first SS blocks and indices of the plurality of second SS blocks.

[0449] Based on the SS block index within the first burst matching the SS block index within the second burst, the first SS block and the second SS block may have a QCL relationship.

[0450] The plurality of first SS blocks arranged in the SS block index order within the first burst may sequentially have a QCL relationship with the plurality of second SS blocks arranged in the SS block index order within the second burst.

[0451] Information about the above switching may include information about the index of the second pattern or the configuration of the second burst related to the second pattern.

[0452] Information about the configuration of the second burst may include information about indices of the plurality of second SS blocks transmitted within the second burst.

[0453] Information about the above switching may be transmitted via DCI (downlink control information) or PDSCH (physical downlink shared channel) scheduled by the DCI.

[0454] A first time length from the leading first SS block to the last first SS block within the first burst may be different from a second time length from the leading second SS block to the last second SS block within the second burst.

[0455] A first time gap between the plurality of first SS blocks within the first burst may be different from a second time gap between the plurality of second SS blocks within the second burst.

[0456] The embodiments described above are combinations of components and features of the present disclosure in a predetermined form. Each component or feature should be considered optional unless explicitly stated otherwise. Each component or feature may be implemented without being combined with other components or features. Furthermore, it is also possible to form embodiments of the present disclosure by combining some components and / or features. The order of operations described in the embodiments of the present disclosure may be changed. Some components or features of one embodiment may be included in another embodiment or may be replaced with corresponding components or features of another embodiment. It is self-evident that claims that do not have an explicit citation relationship in the patent claims may be combined to form embodiments or incorporated as new claims through post-application amendments.

[0457] It will be apparent to those skilled in the art that the present disclosure may be embodied in other specific forms without departing from the scope of the present disclosure. Therefore, the above detailed description should not be construed as limiting in any respect, but rather as illustrative. The scope of the present disclosure should be determined by a reasonable interpretation of the appended claims, and all modifications within the scope of equivalents of the present disclosure are intended to be included within the scope of the present disclosure.

[0458] The present disclosure may be used in a terminal, base station, or other equipment of a wireless mobile communication system.

Claims

1. There is a method performed by a terminal, Receiving information about switching from a first pattern to a second pattern among a plurality of patterns related to transmission of a burst including a plurality of SS (synchronization signal) blocks; and Receiving at least one second SS block among a plurality of second SS blocks belonging to a second burst related to the second pattern, A method in which the terminal obtains QCL (quasi co-location) information for at least one second SS block based on at least one first SS block among a plurality of first SS blocks belonging to a first burst related to the first pattern.

2. In paragraph 1, A method wherein the terminal determines at least one first SS block to provide the QCL information to at least one second SS block based on a linkage between the plurality of first SS blocks and the plurality of second SS blocks.

3. In paragraph 2, A method wherein the linkage between the plurality of first SS blocks and the plurality of second SS blocks includes a mapping between indices of the plurality of first SS blocks and indices of the plurality of second SS blocks.

4. In paragraph 1, A method wherein the terminal determines that the first SS block and the second SS block have a QCL relationship based on the SS block index within the first burst matching the SS block index within the second burst.

5. In the first paragraph, the terminal, A method for determining that the plurality of first SS blocks sorted in the order of SS block indexes within the first burst have a QCL relationship with the plurality of second SS blocks sorted in the order of SS block indexes within the second burst.

6. In paragraph 1, A method wherein the information about the switching includes information about the index of the second pattern or the configuration of the second burst related to the second pattern.

7. In paragraph 6, A method wherein information about the configuration of the second burst includes information about indices of the plurality of second SS blocks transmitted within the second burst.

8. In paragraph 1, A method in which information about the above switching is received through DCI (downlink control information) or PDSCH (physical downlink shared channel) scheduled by the DCI.

9. In paragraph 1, A method wherein a first time length from a leading first SS block to a last first SS block within the first burst is different from a second time length from a leading second SS block to a last second SS block within the second burst.

10. In paragraph 1, A method wherein a first time gap between the plurality of first SS blocks within the first burst is different from a second time gap between the plurality of second SS blocks within the second burst.

11. A non-transitory computer-readable recording medium having recorded thereon a program for performing the method described in paragraph 1.

12. In the device, at least one processor; and At least one memory configured to store instructions that are executed by said at least one processor to cause said at least one processor to perform operations, The operations of the above processor are: Receiving information about switching from a first pattern to a second pattern among a plurality of patterns related to transmission of a burst including a plurality of SS (synchronization signal) blocks; and Receiving at least one second SS block among a plurality of second SS blocks belonging to a second burst related to the second pattern, A device that obtains QCL (quasi co-location) information for at least one second SS block based on at least one first SS block among a plurality of first SS blocks belonging to a first burst related to the first pattern.

13. In paragraph 12, A device wherein the above device is a terminal including a transceiver or a processing device configured to control the terminal.

14. In a method performed by a base station, Transmitting information about switching from a first pattern to a second pattern among a plurality of patterns related to transmission of a burst including a plurality of SS (synchronization signal) blocks; and comprising transmitting at least one second SS block among a plurality of second SS blocks belonging to a second burst related to the second pattern; A method, wherein at least one first SS block among a plurality of first SS blocks belonging to a first burst related to the first pattern has a QCL (quasi co-location) relationship with at least one second SS block.

15. At the base station, at least one processor; and At least one memory configured to store instructions that are executed by said at least one processor to cause said at least one processor to perform operations, The operations of the above processor are: Transmitting information about switching from a first pattern to a second pattern among a plurality of patterns related to transmission of a burst including a plurality of SS (synchronization signal) blocks; and comprising transmitting at least one second SS block among a plurality of second SS blocks belonging to a second burst related to the second pattern; A base station, wherein at least one first SS block among a plurality of first SS blocks belonging to a first burst related to the first pattern has a QCL (quasi co-location) relationship with at least one second SS block.

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