Method for receiving downlink signals, user equipment, processing equipment and storage medium, and method for transmitting downlink signals, base station, processing equipment and storage medium

Abstract

The UE according to the present invention, when on a first frequency band supporting TN and NTN, can attempt SSB detection based on a first SSB timing pattern defined for the TN; and can attempt SSB detection based on a second SSB timing pattern defined for the NTN. The second SSB timing pattern may include fewer SSB timings than the number of SSB timings in the first SSB timing pattern.

Description

[Technical Field]

[0001] This invention relates to a wireless communication system. [Background technology]

[0002] A variety of devices and technologies have emerged and become widespread, including machine-to-machine (M2M) communication, machine-type communication (MTC), and smartphones and tablet PCs (Personal Computers) that demand high data transmission capacities. Consequently, the amount of data required to be processed on cellular networks is increasing at a very rapid pace. To satisfy this rapidly increasing data processing demand, technologies such as carrier aggregation and cognitive radio, which efficiently utilize more frequency bands, and multiplex antenna and multiplex base station (BS) cooperation technologies, which increase the data transmission capacity within limited frequencies, are being developed.

[0003] In recent years, when providing wireless communication services via terrestrial networks, there has been consideration to supporting wireless communication services via non-terrestrial networks (NTN) in locations where ground connectivity is technically extremely difficult or costly. [Overview of the project] [Problems that the invention aims to solve]

[0004] A solution is needed for accurately and efficiently delivering wireless communication signals to a UE (Union Engine) via an airborne platform or space.

[0005] Furthermore, there is a need for a plan that allows terrestrial networks and NTN to coexist efficiently.

[0006] The technical challenges that this specification aims to address are not limited to those mentioned above, and other technical challenges not mentioned will be clearly understood by those with ordinary skill in the art related to this specification from the detailed description below. [Means for solving the problem]

[0007] In one aspect of this specification, a method is provided for a user device to receive a downlink signal in a wireless communication system. The method includes: attempting to detect a synchronization block (SSB) on a first frequency band supporting a terrestrial network (TN) and a non-terrestrial network (NTN); obtaining time and frequency synchronization with a cell based on the detection of an SSB on the cell; and transmitting a physical random access channel (PRACH) based on the SSB. Attempting to detect the SSB on the first frequency band includes: attempting to detect the SSB based on a first SSB timing pattern defined for the TN; and attempting to detect the SSB based on a second SSB timing pattern defined for the NTN. The second SSB timing pattern includes fewer SSB timings than the number of SSB timings in the first SSB timing pattern.

[0008] In another aspect of this specification, a user device for receiving downlink signals in a wireless communication system is provided. The user device includes: at least one transceiver; at least one processor; and at least one computer memory operably connectable to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations according to some implementations of this specification. The operations include: attempting to detect a synchronization block (SSB) on a first frequency band supporting a terrestrial network (TN) and a non-terrestrial network (NTN); obtaining time and frequency synchronization with a cell based on the detection of an SSB on the cell; and transmitting a physical random access channel (PRACH) based on the SSB. Attempting to detect the SSB on the first frequency band includes: attempting to detect the SSB based on a first SSB timing pattern defined for the TN; and attempting to detect the SSB based on a second SSB timing pattern defined for the NTN. The second SSB timing pattern includes fewer SSB timings than the number of SSB timings in the first SSB timing pattern.

[0009] In yet another aspect of this specification, a processing device is provided. The processing device includes: at least one processor; and at least one computer memory operably connectable to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations according to some implementations of this specification. The operations include: attempting to detect a synchronization block (SSB) on a first frequency band supporting a terrestrial network (TN) and a non-terrestrial network (NTN); obtaining time and frequency synchronization with a cell based on the detection of an SSB on the cell; and transmitting a physical random access channel (PRACH) based on the SSB. Attempting to detect the SSB on the first frequency band includes: attempting to detect the SSB based on a first SSB timing pattern defined for the TN; and attempting to detect the SSB based on a second SSB timing pattern defined for the NTN. The second SSB timing pattern includes fewer SSB timings than the number of SSB timings in the first SSB timing pattern.

[0010] In another aspect of this specification, a computer-readable storage medium is provided. The storage medium stores, when executed, at least one program code containing instructions causing at least one processor to perform an operation, the operation including: attempting to detect a synchronization block (SSB) on a first frequency band supporting a terrestrial network (TN) and a non-terrestrial network (NTN); obtaining time and frequency synchronization with a cell based on the detection of an SSB on the cell; and transmitting a physical random access channel (PRACH) based on the SSB. Attempting to detect the SSB on the first frequency band includes: attempting to detect the SSB based on a first SSB timing pattern defined for the TN; and attempting to detect the SSB based on a second SSB timing pattern defined for the NTN. The second SSB timing pattern includes fewer SSB timings than the number of SSB timings in the first SSB timing pattern.

[0011] In each embodiment of this specification, attempting SSB detection based on the first SSB timing pattern can be performed in a synchronous raster defined for the TN.

[0012] In each embodiment of this specification, attempting SSB detection based on the second SSB timing pattern can be performed in a synchronous raster defined for NTN.

[0013] In each embodiment of this specification, each SSB timing in the first SSB timing pattern and the second SSB timing pattern may correspond to a (candidate) SSB (or (candidate) SSB index) in a synchronization signal (SS) burst transmitted at a predetermined period.

[0014] In each embodiment of this specification, the SSB timing in the first SSB timing pattern can be associated with a (candidate) SSB (or (candidate) SSB index) in a first synchronization signal (SS) burst, and the SSB timing in the second SSB timing pattern can be associated with a (candidate) SSB (or (candidate) SSB index) in a second SS burst.

[0015] In each embodiment of this specification, the second SS burst and the second SS burst may exist in different half-frames.

[0016] In each embodiment of this specification, the first SSB timing pattern may appear in the first period, and the second SSB timing pattern may appear in the second period, which is longer than the first period.

[0017] In each embodiment of this specification, the method or operation may include: attempting SSB detection based on a third SSB timing pattern defined for TN on a second frequency band that does not support NTN.

[0018] The aforementioned problem-solving methods are only a part of the examples provided herein, and a variety of other examples reflecting the technical features of this specification can be derived and understood by those with ordinary skill in the art based on the following detailed explanation. [Effects of the Invention]

[0019] According to some implementations of this specification, wireless communication signals can be efficiently transmitted / received via airborne platforms or in space. This can improve the overall throughput of the wireless communication system.

[0020] Some implementations of this specification can guarantee the continuity of wireless communication services, enhance the reliability of wireless communication services through connectivity between various connection technologies, and improve network resilience and reliability against disasters.

[0021] Some implementations of this specification can support the coexistence of non-terrestrial networks (NTN) and terrestrial networks (TN).

[0022] As demonstrated in some implementations of this specification, the UE can effectively detect synchronization signal blocks (SSBs) even in the presence of both NTN and TN frequency bands.

[0023] The effects described herein are not limited to those mentioned above, and other effects not mentioned herein will be clearly understood by those with ordinary skill in the art relating to this specification from the detailed description below. [Brief explanation of the drawing]

[0024] The accompanying drawings, included as part of the detailed description to aid in understanding the implementation of this specification, provide examples of implementation and illustrate the implementation of this specification together with the detailed description: [Figure 1] This shows an example of a communication system 1 to which the implementation of this specification can be applied. [Figure 2] This block diagram shows an example of a communication device capable of performing the method described herein. [Figure 3] This shows an example of a frame structure usable in a 3GPP-based wireless communication system. [Figure 4] This is an example of a resource grid for slots. [Figure 5] This illustrates multiplex-beam operation in a 3GPP-based system. [Figure 6] This shows an example of SS / PBCH block (SSB) transmission on a cell. [Figure 7] This illustrates the structure of a non-terrestrial network (NTN). [Figure 8] This illustrates the synchronous raster and channel raster used in several implementations. [Figure 9] This illustrates a situation where terrestrial networks (TN) and non-terrestrial networks (NTN) coexist. [Figure 10] This illustrates an SSB structure transmitted via BS. [Figure 11] This document illustrates some aspects of the SSB reception process involved in several implementations of this specification. [Figure 12] This document illustrates the distinction between NTN and TN in relation to some of the implementations of this specification. [Figure 13] This document illustrates the distinction between NTN and TN in relation to other implementations of this specification. [Figure 14] This document illustrates the distinction between NTN and TN in relation to other implementations of this specification. [Figure 15] This document illustrates the distinction between NTN and TN in relation to other implementations of this specification. [Figure 16] This illustrates some of the downlink reception flows involved in the implementation of several aspects of this specification. [Figure 17] This illustrates some of the downlink transmission flows in several implementations of this specification. [Modes for carrying out the invention]

[0025] The implementations described herein will be described in detail below with reference to the accompanying drawings. The detailed description disclosed below, together with the accompanying drawings, is intended to illustrate exemplary implementations of this specification and does not represent the only possible forms in which this specification may be implemented. The following detailed description includes specific details to provide a complete understanding of this specification. However, those skilled in the art will understand that this specification can be implemented even without these specific details.

[0026] In some cases, known structures and devices may be omitted or illustrated in block diagrams focusing on the core function of each structure and device, in order to avoid ambiguity of the concepts described herein. Furthermore, identical components throughout this specification will be denoted by the same reference numerals.

[0027] The techniques, equipment, and systems described below can be applied to various wireless multiplexing systems.

[0028] For the sake of explanation, the following specifications will be based on communication systems compliant with 3GPP (3rd Generation Partnership Project). However, the technical features of these specifications are not limited to these. For example, even if the following detailed descriptions are based on 3GPP (3rd Generation Partnership Project) LTE or 5G technology, some implementations of these specifications are applicable to any other mobile communication system and future systems (e.g., 6G), with the exception of those specific to 3GPP LTE / 5G.

[0029] For terms and techniques used herein that are not specifically described, please refer to the 3GPP standard documents, e.g., 3GPP TS 23.304, 3GPP TS 23.285, 3GPP TS 23.287, 3GPP TS 24.587, 3GPP TS 36.211, 3GPP TS 36.212, 3GPP TS 36.213, 3GPP TS 36.300, 3GPP TS 36.321, 3GPP TS 36.322, 3GPP TS 36.323, 3GPP TS 36.331, 3GPP TS 37.213, 3GPP TS 38.211, 3GPP TS 38.212, 3GPP TS 38.213, 3GPP TS You can refer to 38.214, 3GPP TS 38.300, 3GPP TS 38.321, 3GPP TS 38.322, 3GPP TS 38.323, and 3GPP TS 38.331, among others.

[0030] In the examples of this specification described later, when a device is described as “assuming,” this may mean that the entity transmitting the channel transmits the channel in a manner that conforms to the “assumment.” The entity receiving the channel may mean that, on the premise that the channel was transmitted in a manner that conforms to the “assumment,” it receives or decodes the channel in a manner that conforms to the “assum.”

[0031] In this specification, a UE may be fixed or mobile and includes various devices that communicate with a BS (base station, BS) to transmit and / or receive user data and / or various control information. A UE may also be called a TE (Terminal Equipment), MS (Mobile Station), MT (Mobile Terminal), UT (User Terminal), etc. In this specification, a BS usually means a fixed station that communicates with a UE and / or other BSs to exchange various data and control information. A BS may also be called by other terms such as ABS (Advanced Base Station), NB (Node-B), eNB (evolved-Node-B), gNB, BTS (Base Transceiver System), Access Point, PS (Processing Server), etc. For convenience of explanation below, base stations will be collectively referred to as BS regardless of the type or version of communication technology.

[0032] In this specification, a node is a fixed point capable of communicating with a UE and transmitting / receiving radio signals. Various forms of BS can be used as nodes, regardless of their name. A node is equipped with at least one antenna. The antenna may be a physical antenna, an antenna port, a virtual antenna, or an antenna group. A node is sometimes referred to as a point.

[0033] On the other hand, 3GPP-based communication systems use the concept of cells to manage radio resources, but cells related to radio resources are distinct from cells in geographical areas. A "cell" in a geographical area can be understood as the coverage over which a node can provide services using a carrier, while a "cell" of radio resources is associated with the bandwidth (BW), which is the frequency range configured by the carrier. Downlink coverage, which is the range over which a node can transmit a valid signal, and uplink coverage, which is the range over which a valid signal can be received from a UE, depend on the carrier that carries the signal. Therefore, a node's coverage may be associated with the coverage of the "cells" of radio resources used by that node. Thus, the term "cell" is used to mean, in some cases, the coverage of services provided by a node; in some cases, the radio resources themselves; and in some cases, the range over which signals using those radio resources can reach with valid strength.

[0034] A “cell” in relation to wireless resources can be defined as a combination of downlink resources (DL resources) and uplink resources (UL resources), i.e., a combination of a DL component carrier (CC) and an UL CC. A cell can be configured as a DL resource alone, or as a combination of DL and UL resources. If carrier aggregation is supported, the linkage between the carrier frequency of the DL resource (or DL ​​CC) and the carrier frequency of the UL resource (or UL CC) can be indicated by system information. Here, the carrier frequency may be the same as or different from the center frequency of each cell or each CC.

[0035] In a wireless communication system, the UE receives information from the BS via the downlink (DL), and the UE transmits information to the BS via the uplink (UL). The information transmitted and / or received by the BS and UE includes data and various control information, and various physical channels exist depending on the type and purpose of the information they transmit and / or receive.

[0036] 3GPP-based communication standards define downlink physical channels corresponding to resource elements that carry information originating from higher layers, and downlink physical signals corresponding to resource elements used by the physical layer but not carrying information originating from higher layers. For example, physical downlink shared channels (PDSCH), physical broadcast channels (PBCH), and physical downlink control channels (PDCCH) are defined as downlink physical channels, while reference signals and synchronization signals are defined as downlink physical signals. A reference signal (RS), also called a pilot, refers to a predefined special waveform signal that is known to both the BS and UE. For example, demodulation reference signals (DMRS) and channel state information RS (CSI-RS) are defined as downlink reference signals. 3GPP-based communication standards define uplink physical channels corresponding to resource elements that carry information originating from higher layers, and uplink physical signals corresponding to resource elements used by the physical layer but not carrying information originating from higher layers. For example, the physical uplink shared channel (PUSCH), physical uplink control channel (PUCCH), and physical random access channel (PRACH) are defined as uplink physical channels, and demodulation reference signals (DMRS) for uplink control / data signals and sounding reference signals (SRS) used for uplink channel measurements are also defined.

[0037] In this specification, PDCCH means a set of time-frequency resources (e.g., resource elements, RE) that carry downlink control information (DCI), and PDSCH means a set of time-frequency resources that carry downlink data. PUCCH, PUSCH, and PRACH respectively mean a set of time-frequency resources that carry uplink control information (UCI), uplink data, and an optional connection preamble. Hereafter, the expression that a UE / BS transmits / receives PUCCH / PUSCH / PRACH is used to mean the same as transmitting / receiving UCI / uplink data / optional connection preamble on or via PUCCH / PUSCH / PRACH, respectively. Furthermore, the expressions "BS / UE transmits / receives PBCH / PDCCH / PDSCH" are used interchangeably with "transmits / receives broadcast information / DCI / downlink data over or via PBCH / PDCCH / PDSCH," respectively.

[0038] In this specification, radio resources (e.g., time-frequency resources) scheduled or set up by a BS for a UE for the transmission or reception of PUCCH / PUSCH / PDSCH may also be referred to as PUCCH / PUSCH / PDSCH resources.

[0039] Since communication equipment receives physical channels and / or physical signals on a cell in the form of radio signals, it is not possible to selectively receive only radio signals containing only specific physical channels or specific physical signals via a radio frequency (RF) receiver, or to selectively receive only radio signals excluding only specific physical channels or physical signals via an RF receiver. In actual operation, communication equipment first receives the radio signal on a cell via an RF receiver, converts the radio signal, which is an RF band signal, into a baseband signal, and decodes the physical signals and / or physical channels within the baseband signal using one or more processors. Therefore, in some implementations of this specification, not receiving a physical signal and / or physical channel may not actually mean that the communication equipment does not receive a radio signal containing such physical signals and / or physical channels at all, but rather that it does not attempt to reconstruct the physical signals and / or physical channels from the radio signal, for example, it does not attempt to decode the physical signals and / or physical channels.

[0040] Figure 1 shows an example of a communication system 1 to which the implementation of this specification can be applied.

[0041] Referring to Figure 1, the communication system 1 to which this specification applies includes wireless equipment, BS, and a network. Here, wireless equipment may mean equipment that communicates using wireless connectivity technologies (e.g., 5G NR (New RAT), LTE (e.g., E-UTRA), WiFi, and 6G to be introduced in the future).

[0042] Wireless devices, though not limited to these, may include robots 100a, transport devices 100b-1, 100b-2, 100b-3, 100b-4, XR (eXtended Reality) devices 100c, handheld devices 100d, home appliances 100e, IoT (Internet of Things) devices 100f, and AI devices / servers 400. For example, transport devices may include ground transport devices with wireless communication capabilities, autonomous transport devices, and transport devices capable of communicating with each other. Here, transport devices may include UAVs (Unmanned Aerial Vehicles) (e.g., drones) and UAMs (Urban Air Mobility) (e.g., unmanned aerial traffic). XR devices may include AR (Augmented Reality) / VR (Virtual Reality) / MR (Mixed Reality) devices. Mobile devices may include smartphones, smart pads, wearable devices (e.g., smartwatches, smart glasses), and computers (e.g., notebook computers). Home appliances may include TVs, refrigerators, washing machines, etc. IoT devices may include sensors, smart meters, etc. For example, BS and networks may be implemented as wireless devices, and certain wireless devices may act as BS / network nodes for other wireless devices.

[0043] Wireless devices 100a to 100f can be connected to the network via BS200. Artificial Intelligence (AI) technology is applied to wireless devices 100a to 100f, and wireless devices 100a to 100f can be connected to the AI ​​server 400 via the network. Wireless devices 100a to 100f may communicate with each other via BS200 / network, but they can also communicate directly without going through BS / network (e.g., sidelink communication). For example, transport devices 100b-1, 100b-2, 100b-3, and 100b-4 can communicate directly (e.g., V2V (Vehicle to Vehicle) / V2X (Vehicle to everything) communication). In addition, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices 100a to 100f.

[0044] Wireless communication / connection can be performed between wireless devices 100a-100f / BS200-BS200 / wireless devices 100a-100f. In this wireless communication / connection, uplink / downlink communication (UL / DL) and sidelink communication (SL) (or D2D communication) can be performed by various wireless connection technologies (e.g., 5G NR). Through wireless communication / connection (UL / DL, SL), wireless devices and BS / wireless devices can transmit / receive wireless signals from each other. To this end, at least some of the following can be performed based on the various proposals herein: various configuration information setting processes for the transmission / reception of wireless signals, various signal processing processes (e.g., channel coding / decoding, modulation / demodulation, resource mapping / demapping, etc.), and resource allocation processes.

[0045] Figure 2 is a block diagram showing an example of a communication device capable of implementing the method according to this specification. Referring to Figure 2, the first wireless device 100 and the second wireless device 200 can transmit / receive wireless signals by various wireless connection technologies. Here, {first wireless device 100, second wireless device 200} can correspond to {wireless device 100x, BS200} and / or {wireless device 100x, wireless device 100x} in Figure 1.

[0046] The first radio device 100 and the second radio device 200 each include one or more processors 102, 202 and one or more memories 104, 204, and may further include one or more transceivers 106, 206 and / or one or more antennas 108. The processors 102, 202 can control the memories 104, 204 and / or the transceivers 106, 206 and be configured to implement the functions, procedures and / or methods described / proposed below. For example, the processors 102, 202 can process information in the memories 104, 204 to generate first information / signals, and then transmit a radio signal containing the first information / signals via the transceivers 106, 206. Alternatively, the processors 102, 202 can receive a radio signal containing second information / signals via the transceivers 106, 206, and then store the information obtained from the signal processing of the second information / signals in the memories 104, 204. Memories 104 and 204 are connected to processors 102 and 202 and can store various information related to the operation of processors 102 and 202. For example, memories 104 and 204 can store software code that includes instructions for executing some or all of the processes controlled by processors 102 and 202, or for executing the procedures and / or methods described / proposed below. Here, processors 102 and 202 and memories 104 and 204 may be part of a communication modem / circuit / chip designed to implement wireless communication technology. Transceivers 106 and 206 are connected to processors 102 and 202 and can transmit and / or receive wireless signals via one or more antennas 108 and 208. Transceivers 106 and 206 may include a transmitter and / or receiver.

[0047] Without limiting itself, one or more protocol layers can be implemented by one or more processors 102, 202. For example, one or more processors 102, 202 can implement one or more layers (e.g., a physical (PHY) layer, a medium access control (MAC) layer, a radio link control (RLC) layer, a packet data convergence protocol (PDCP) layer, a radio resource control (RRC) layer, a service data adaptation protocol (SDAP) layer, and other functional layers). One or more processors 102, 202 can generate one or more protocol data units (PDUs) and / or one or more service data units (SDUs) according to the functions, procedures, proposals and / or methods disclosed herein. One or more processors 102, 202 can generate messages, control information, data, or information according to the functions, procedures, proposals and / or methods disclosed herein. One or more processors 102, 202 can generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information in accordance with the functions, procedures, suggestions, and / or methods disclosed herein and provide them to one or more transceivers 106, 206. One or more processors 102, 202 can receive signals (e.g., baseband signals) from one or more transceivers 106, 206 and acquire PDUs, SDUs, messages, control information, data, or information in accordance with the functions, procedures, suggestions, and / or methods disclosed herein.

[0048] One or more processors 102, 202 may be referred to as a controller, microcontroller, microprocessor, or microcomputer. One or more processors 102, 202 can be implemented by hardware, firmware, software, or a combination thereof, and the firmware or software can be implemented to include modules, procedures, functions, etc. Firmware or software configured to perform the functions, procedures, proposals and / or methods disclosed herein may be contained in one or more processors 102, 202 or stored in one or more memories 104, 204 and driven by one or more processors 102, 202. The functions, procedures, proposals and / or methods disclosed herein can be implemented using firmware or software in the form of code, instructions and / or sets of instructions.

[0049] One or more memory units 104, 204 are connected to one or more processors 102, 202 and can store various forms of data, signals, messages, information, programs, code, instructions, and / or commands. One or more memory units 104, 204 can be located inside and / or outside of one or more processors 102, 202. Furthermore, one or more memory units 104, 204 can be connected to one or more processors 102, 202 via various technologies such as wired or wireless connections.

[0050] One or more transceivers 106, 206 can transmit / receive user data, control information, radio signals / channels, etc., as referred to in the methods and / or operation flowcharts disclosed herein, etc., to and from one or more other devices. Furthermore, one or more processors 102, 202 can control one or more transceivers 106, 206 to transmit / receive user data, control information, or radio signals to and from one or more other devices. In addition, one or more transceivers 106, 206 can be connected to one or more antennas 108, 208, and can be configured to transmit and / or receive user data, control information, radio signals / channels, etc., as referred to in the functions, procedures, proposals, methods and / or operation flowcharts disclosed herein, etc. In this specification, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). Furthermore, one or more transceivers 106, 206 can convert received user data, control information, radio signals / channels, etc. from RF band signals to baseband signals for processing using one or more processors 102, 202. One or more transceivers 106, 206 can convert user data, control information, radio signals / channels, etc. processed by one or more processors 102, 202 from baseband signals to RF band signals. For this purpose, one or more transceivers 106, 206 may include (analog) oscillators and / or filters.

[0051] In this specification, at least one memory 104, 204 can store instructions or programs, and the instructions or programs can be configured to cause at least one processor 102, 202, which is operably connected to the at least one memory, to perform some of the actions described herein in certain embodiments or implementations when executed.

[0052] In this specification, a computer-readable (non-transitory) storage medium can store at least one instruction or computer program, and the at least one instruction or computer program can be configured, when executed by at least one processor, to cause the at least one processor to perform some of the embodiments or operations described herein.

[0053] Figure 3 shows an example of a frame structure that can be used in a 3GPP-based wireless communication system.

[0054] The frame structure in Figure 3 is merely an example, and the number of subframes, slots, and symbols in a frame can be varied. In some wireless communication systems, OFDM numerology (e.g., subcarrier spacing, SCS) can be set differently among multiple cells aggregated under a single UE. This allows the duration (absolute time) of time resources (e.g., subframes, slots, or transmission time intervals, TTI) consisting of the same number of symbols to be set differently among the aggregated cells. Here, symbols can include OFDM symbols (or cyclic prefix-orthogonal frequency division multiplexing, CP-OFDM) symbols, SC-FDMA symbols (or discrete Fourier transform-spread-OFDM (DFT-s-OFDM) symbols). In this specification, symbols, OFDM-based symbols, OFDM symbols, CP-OFDM symbols, and DFT-s-OFDM symbols are interchangeable.

[0055] Referring to FIG. 3, uplink and downlink transmissions are organized by frames. Each frame has a period of T f =(Δf max *N f / 100)*T c =10 ms, where T is the basic time unit c =1 / (Δf max *N f ), Δf max =480 * 10 3 Hz, and N f =4096. For reference, the sampling time T s =1 / (Δf ref *N f,ref ), Δf ref =15 * 10 3 Hz, and N f,ref =2048. T c and T s have a relationship of constant κ = Ts / Tc = 64. A frame is composed of 10 sub - frames, and the period T sf of a single sub - frame is 1 ms. A sub - frame is further divided into slots, and the number of slots in a sub - frame depends on the sub - carrier spacing. Each slot can be composed of N slot symb symbols based on the cyclic prefix (CP). For example, in some scenarios, for normal CP, each slot is composed of 14 OFDM symbols, and for extended CP, each slot is composed of 12 OFDM symbols. The said numerology depends on the exponentially scalable sub - carrier spacing Δf = 2 u *15 kHz. The following table shows the number of OFDM symbols per slot (N u *15 kHz with respect to normal CP), the number of slots per frame (N slot symb ), and the number of slots per sub - frame (N frame,u slot ) for sub - carrier spacing Δf = 2subframe,u slot ) indicates.

[0056] [Table 1]

[0057] The following table shows the subcarrier interval △f=2 for extended CP. u *This shows the number of OFDM symbols per slot, the number of slots per frame, and the number of slots per subframe at 15kHz.

[0058] [Table 2]

[0059] Given a subcarrier interval setting u, the slots are arranged in increasing order within the subframe, n. u s ∈{0,...,n subframe,u slot As {-1}, and in increasing order within the frame, n us,f ∈{0,...,n frame,u slot It is numbered as -1}.

[0060] In the following, the smallest unit of time for scheduling uplink, downlink, and sidelink transmissions will be referred to as a slot, and the implementation of this specification will be described accordingly. However, in some wireless communication systems, the smallest unit of time for scheduling may be referred to by other terms. For example, in LTE-based systems, the smallest unit of time for scheduling transmissions is called a subframe or transmission time interval (TTI), while in NR-based systems, the smallest unit of time for scheduling is called a slot.

[0061] Figure 4 illustrates a resource grid of slots. Slots are multiple (for example, N) in the time domain. slot symbIncludes the symbol of ). For each neurology (e.g., subcarrier interval) and carrier, a common resource block (CRB) N is indicated by higher-level signaling (e.g., radio resource control (RRC) signaling). start,u grid Starting from, N size,u grid,x *N RB sc Individual subcarriers and N subframe,u symb A resource grid of N OFDM symbols is defined. Here, N size,u grid,x is the number of resource blocks (RBs) in the resource grid, where the subscript x is DL for downlinks and UL for uplinks. RB sc This is the number of subcarriers per RB, and in 3GPP-based wireless communication systems, N RB sc It is usually 12. There is one resource grid for a given antenna port p, subcarrier spacing setting u, and transmission direction (DL or UL). Carrier bandwidth N for subcarrier spacing setting u size,u gridThis is provided to the UE by higher-level parameters from the network (e.g., RRC parameters). Each element in the resource grid for the antenna port p and subcarrier spacing setting u is called a resource element (RE), and each resource element can be mapped to one complex-valued symbol. Each resource element in the resource grid is uniquely identified by index k in the frequency domain and index l in the time domain, which indicates the symbol position relative to a reference point. RBs can be classified into common resource blocks (CRBs) and physical resource blocks (PRBs). CRBs are numbered upwards from 0 in the frequency domain for the subcarrier spacing setting u. The center of subcarrier 0 in CRB0 for subcarrier spacing setting u coincides with "point A", which is the common reference point of the resource block grid. PRBs for subcarrier spacing setting u are defined within the bandwidth part (BWP), from 0 to N size,u BWP,i-1 The numbers are numbered up to, where i is the number of the bandwidth part. Common resource block n u CRB and physical resource block n within bandwidth part i PRB The relationship is as follows: n u PRB =n u CRB +N start,u BWP,i , here, N start,u BWP,i This is a common resource block in which the bandwidth part starts relative to CRB0. BWP contains multiple contiguous RBs in the frequency domain. For example, BWP is a given neural u within BWPi on a given carrier. iThis is a subset of consecutive CRBs defined for a given component carrier. A carrier wave can contain up to N (e.g., 5) BWPs. A UE can be configured to have one or more BWPs on a given component carrier wave. Data communication is performed via activated BWPs, and only a predetermined number (e.g., 1) of the BWPs configured on the UE can be activated on that carrier wave.

[0062] In a 3GPP-based system, a control resource set (CORESET) can be defined and / or configured, which is a set of time-frequency resources that a UE can use to monitor PDCCHs. One or more CORESETs can be configured on the UE. A CORESET consists of a set of physical resource blocks (PRBs) having durations for one to three OFDM symbols. The PRBs and CORESET durations that make up the CORESET can be provided to the UE via higher-level (e.g., RRC) signaling. Within the configured CORESET, a set of PDCCH candidates is monitored according to the search space set. In this specification, “monitoring” means decoding each PDCCH candidate according to the DCI format being monitored (so-called blind decoding). The master information block (MIB) on the PBCH provides the UE with PDCCH monitoring parameters (e.g., CORESET#0 settings) for scheduling PDSCHs carrying system information block 1 (SIB1). PBCH can also indicate that no associated SIB1 exists, in which case UE can receive instructions for other frequencies to search for an associated SSB with SIB1, in addition to the frequency range in which it can be assumed that no SSB associated with SIB1 exists. CORESET#0, which is a CORESET for scheduling at least SIB1, can be set via MIB or dedicated RRC signaling.

[0063] The set of PDCCH candidates monitored by the UE is defined in terms of PDCCH search space sets. A search space set may be a common search space (CSS) set or a UE-specific search space (USS) set. Each CORESET setting is associated with one or more search space sets, and each search space set is associated with one CORESET setting.

[0064] Figure 5 illustrates the operation of multiplexed beams in a 3GPP-based system.

[0065] 5G and subsequent 3GPP-based systems can utilize ultra-high frequency bands, such as millimeter frequency bands above 6 GHz, to transmit data to a large number of users while maintaining a high transmission rate using a wide frequency band. However, due to the use of extremely high frequency bands, millimeter frequency bands have frequency characteristics in which signal attenuation with distance occurs very rapidly. Therefore, when using a band of at least 6 GHz or higher, 3GPP-based systems use narrow beam transmission technology to compensate for the rapid radio wave attenuation characteristics. This is achieved by concentrating energy in a specific direction rather than transmitting the signal in all directions (omni-direction), thereby solving the problem of reduced coverage due to rapid radio wave attenuation. However, if a service is provided using only one narrow beam, the range that a single BS can service becomes narrow. Therefore, BS combines multiple narrow beams to provide service as a wider beam.

[0066] Figure 6 shows an example of SS / PBCH block (SSB) transmission on a cell.

[0067] In a 3GPP-based system, each SSB is associated with a specific beam. For example, different SSBs can be transmitted in different spatial directions (using different beams spanning the cell's coverage area) during a half-frame. The possible time positions of SSBs within a half-frame are determined by the subcarrier interval, and the periodicity of the half-frame in which the SSBs are transmitted is set by the network. Multiple SSBs can be transmitted within the carrier frequency span. Different indices of SSBs transmitted / detected on a single cell can correspond to different BS (wide) Tx beams. In a 3GPP-based system, multi-beam operation is based on beam switching / beam scanning, which transmits / receives signals while changing the beam direction over time. For example, assuming that the BS supports up to N transmission beams, beam sweeping can be performed to transmit synchronous signal blocks (SSBs) consisting of PSS, SSS, and PBCH for each of up to N beam directions (see SSB beam sweeping in Figure 5). A set of SSBs in a beam sweep is specifically referred to as an SS burst set or SS burst. The number of SSBs in an SS burst set represents the number of beams related to the beam sweep. Numerous SSB patterns are defined depending on the frequency bandwidth and subcarrier spacing (SCS). In this specification, SSB patterns are sometimes referred to as SSB timing patterns. For a half-frame of an SSB, the first (OFDM) symbol index s for a candidate SSB can be determined according to the SCS of the SSB as follows, where index 0 corresponds to the first symbol of the first slot in the half-frame. In some scenarios, the SSB patterns shown in the table below can be used.

[0068] [Table 3]

[0069] In the table above, FR indicates the frequency range; for example, FR1 corresponds to the frequency range 410MHz to 7125MHz, and FR2 corresponds to the frequency range 24250MHz to 52600MHz. As can be seen from the table above, the number of SSBs in an SSB burst set may differ depending on the frequency range and SCS. The number of candidate SSBs in a half-frame is numbered from 0 to L' in ascending order of time. max It can be indexed down to -1. max If L' is the maximum number of SSB indices in a cell or the maximum number of SSBs transmitted within a half frame, then in the case of operation without shared spectral channel connections, L' max =L max In the case of operation with shared spectral channel connections, L' max and L max This can differ. For example, in the case of operation where there is a shared spectral channel connection in FR1, L' max =10 and 15kHz SCS for SSB, and L' max = For SSB of 20 and 30 kHz SCS, L max It can be defined as =8.

[0070] SSB(s) are transmitted periodically from 5ms to 160ms. The UE performing the initial connection to the network takes 20ms (for example, assuming two frames; in other words, for an initial cell connection, the UE can assume that half frames containing SSB appear with a periodicity of two frames).

[0071] Referring again to Figure 5, the UE can use the wide reception (Rx) beam to measure the power of the SSB received from the BS transmission (Tx) beam and select its preferred beam. For example, the UE can select one SSB from the detected / received SSBs. 3GPP-based systems define specific mappings between SSBs and random access channel (RACH) timings (occasions) to allow the network to know which beam the UE has selected. RACH timings are the time and frequency resources available for transmitting RACH preambles. Information on how many SSBs can be mapped to a single RACH timing, and how many preamble indices can be mapped to a single SSB, can be provided to the UE by the network. For example, if the network configures the number of SSBs per RACH timing to be 1 / N, one SSB is associated with N RACH timings (where N is a positive integer), and if the network configures the number of SSBs per RACH timing to be N, N preamble indices are mapped to a single SSB. The UE selects an SSB from among the SSBs it detects / receives on the cell, and selects and transmits a RACH timing based on the selected SSB. The BS can recognize which SSB the UE has selected from among the SSBs transmitted on the cell by detecting the RACH timing, including PRACH, from the UE through BS Rx beam sweeping. Based on the SSB selected by the UE, the BS can determine the BS Tx beam for communication with the UE.

[0072] For finer beam tuning, CSI-RS can be transmitted. The beam sweeper (BS) can refine the beam using CSI-RS transmission in a narrower beam around the BS Tx beam, determined based on the RACH timing at which PRACH is detected from the UE (see CSI-RS beam sweeping in Figure 5). The UE can measure the power of the CSI-RS received from these narrow BS Tx beams and report to the BS which of the narrow BS Tx beams it prefers. For example, the UE can measure the CSI-RS on a CSI-RS resource to select at least one CSI-RS resource and report to the BS the CSI-RS resource indicator (CRI) and the reference signal received power (RSRP) of the selected CSI-RS resource. The BS can determine a BS Tx narrow beam based on the CRI and / or RSRP reported by the UE, and by repeatedly transmitting CSI-RS through the BS Tx narrow beam (see P3 CSI-RS beam sweeping in Figure 5), the UE can perform Rx beam sweeping to find a suitable UE Rx beam. The UE can find a suitable UE Rx beam by measuring the power of the CSI-RS received at each UE Rx beam.

[0073] The UE can detect beam failures using CSI-RS / SSB. For example, if the L1-RSRP for a beam to be connected falls below a predetermined limit, the UE determines it is a beam failure and searches for other candidate beams with better quality. After a predetermined number of beam failure detections, a beam failure recovery (BFR) procedure is triggered with the candidate beam. The network can provide the UE with the SSB identifier (ID) transmitted by the cell, which is used when determining a candidate beam for BFR, and the preamble index used when performing BRF to select a candidate beam identified by the SSB. After a predetermined number of beam failure detections, the UE transmits a BFR request to the network by transmitting a PRACH associated with the SSB ID, and the network provides the UE with a random access response (RAR) to the BFR request.

[0074] Upon PDSCH reception, the UE can assume, in relation to the Doppler shift, Doppler spread mean delay, delay spread, and spatial Rx parameters, that the DM-RS port of the PDSCH is quasi-co-located (QCL) with the associated SSB. A transmission configuration indicator (TCI) state can be set / indicated for the PDCCH / PDSCH. The TCI state may include quasi-co-location (QCL) information. For example, the UE can be configured to have M TCI-state settings, provided through higher-level parameters by the BS, so that it can decode the PDSCH according to the detected PDCCH which has a DCI relating to the UE and a given serving cell. Each TCI-state includes one or two downlink reference signals (DL RS) and parameters that set up a QCL relationship between the DM-RS port of the PDSCH, the DM-RS port of the PDCCH, or the CSI-RS port of a CSI-RS resource. The aforementioned QCL relationship is set by the higher-level parameter qcl-type1 for the first DL RS and (if set) the higher-level parameter qcl-type2 for the second DL RS. The QCL type corresponding to each DL RS is given by the higher-level parameter qcl-type in QCL-Info and can take one of the following values.

[0075] - 'typeA':{Doppler shift, Doppler spread, average delay, delay spread}

[0076] - 'typeB':{Doppler shift, Doppler spread}

[0077] - 'typeC':{Doppler shift, average delay}

[0078] - 'typeD':{Spatial Rx parameter}

[0079] Figure 7 illustrates the structure of a non-terrestrial network (NTN).

[0080] In recent years, discussions have progressed on enabling 3GPP-based systems to support non-terrestrial networks (NTNs). An NTN is any network, including non-terrestrial flying objects. Enabling wireless communication via NTNs within 3GPP-based systems will ensure connectivity for wireless communication services, enhance the reliability of wireless communication services through connectivity between various connectivity technologies, and improve the resilience and reliability of networks in the event of disasters. For convenience of explanation, the following terms will be used below.

[0081] - NTN: A radio connectivity network consisting of BS (Bridge Service) that provides non-terrestrial radio access using NTN payloads and NTN gateways mounted on NTN transport equipment in airborne or spaceborne environments.

[0082] - NTN Gateway: An Earth-based station located on the Earth's surface that provides connectivity to NTN payloads using feeder links. The NTN Gateway is a transport network layer (TNL) node.

[0083] - NTN Payload: A network node located on a satellite or high-altitude platform station that provides connectivity between service links and feeder links, or provides high-altitude platform connectivity.

[0084] - Service Link: A wireless link between the NTN payload and the UE (User Environment).

[0085] - Feeder link: A wireless link between the NTN gateway and the NTN payload.

[0086] - Satellite: A space-borne transport device that orbits the Earth carrying an NTN payload.

[0087] - NTN Cell: A cell that provides a service link between the UE and the NTN payload.

[0088] Referring to Figure 7, the NTN gateway is connected via a feeder link to an NTN payload mounted on a satellite or high altitude platform system (HAPS), etc. The NTN payload is connected to the UE via a service link. The NTN gateway can be connected to the core network of a 3GPP-based system.

[0089] The NTN payload transmits radio protocols received from the UE (via the service link) to the NTN gateway (via the feeder link), and transmits radio protocols received from the NTN gateway (via the feeder link) back to the UE (via the feeder link). An NTN gateway can service a large number of NTN payloads, and an NTN payload can be serviced by a large number of NTN gateways. In NTN terms, a tracking area corresponds to a fixed geographical area, and each mapping can be configured in a wireless connectivity network.

[0090] The following three types of service links are supported:

[0091] - Earth-fixed service link: A service link (for example, a GSO satellite) that is provided by a beam(s) that continuously cover the same geographical area.

[0092] - Quasi-Earth-fixed service link: A service link supplied by a beam(s) that covers one geographical area during a limited period and another geographical area during a different period (for example, in the case of an NGSO that generates a steerable beam).

[0093] - Earth-moving service link: A service link whose coverage area is supplied by a beam(s) that glides along the Earth's surface (for example, in the case of NGSO satellites that generate fixed or non-steerable beams).

[0094] NTN can include satellite communication networks, air-to-ground networks, UAV networks, etc. One of the key concepts in NTN is that NTN cells are provided by NGSO (non-geostationary orbit) satellites that periodically orbit the Earth. Each satellite has its own orbit, which is included in satellite position estimation information. Based on satellite position estimation information, the network can predict feeder link switchovers and manage UE mobility and radio resource control. BS providing NTN connectivity can broadcast orbital trajectory information or coordinate-related position estimation information for NTN payloads. EphemerisInfo can provide satellite position estimation in position and velocity state vector format, or in orbital parameter format. The following table illustrates the EphemerisInfo information elements broadcast by BS and describes the fields of EphemerisInfo IE.

[0095] [Table 4]

[0096] [Table 5]

[0097] Satellite communication networks can include LEO (low Earth orbit) satellites, MEO (medium Earth orbit) satellites, and GEO (geosynchronous Earth orbit) satellites, as follows:

[0098] [Table 6]

[0099] The following is an example of an NTN deployment scenario.

[0100] [Table 7]

[0101] Figure 8 illustrates the synchronous raster and channel raster used in several implementations.

[0102] A UE attempting to connect to the network performs a cell search, which is the process by which the UE obtains time and frequency synchronization with the cell and discovers the physical layer cell identity (PCI) of the cell. During the cell search operation, which is performed when the power is turned on, the UE obtains the necessary information required to connect to the cell using the SSB. Performing the cell search, the UE attempts to find the SSB by moving through the frequency domain, assuming a synchronization raster. The synchronization raster shows the possible frequency locations of the SSB that can be used by the UE to obtain system information when explicit signaling of the SSB location is not present. In LTE, the frequency domain location of the PSS / SSS is always fixed around the carrier center frequency (see Figure 8(a)). In contrast, in NR, a set of possible frequency locations for the SSB is defined based on the frequency band, called the synchronization raster, and the UE needs to search for the SSB based on the synchronization raster. Unlike LTE, where the UE searches for PSS / SSS at all carrier raster locations, in NR, a sparser synchronization raster is defined for the UE (see Figure 8(b)). Therefore, in NR, the UE only needs to search for SSB with a sparser synchronization raster compared to LTE. The carrier raster is also called the channel raster, and the channel raster indicates possible carrier locations. The global frequency channel raster is defined by the radio frequency (RF) frequency F REFDefine a set. The RF reference frequency is used for signaling to identify the positions of RF channels, SSB blocks, and other elements. The global frequency raster is used to define all frequencies from 0 to 100 GHz. In NR, the RF reference frequency is the NR absolute radio frequency channel number (NR-ARFCN) and the RF reference frequency F in MHz REF is given by the following formula: F REF =F REF-Offs +ΔF Global (N REF -N REF-Offs ). Here, ΔF Global is the granularity of the frequency raster, N REF is the NR-ARFCN, and F REF-Offs and N REF-Offs are given by the following table.

[0103]

Table 8

[0104] The channel raster defines a subset of RF reference frequencies that can be used to identify RF channel positions in the uplink and downlink.

[0105] The global synchronization raster is defined for all frequencies, and the frequency position of the SSB is defined as SS with the global synchronization channel number (GSCN) of that number REF . For all frequency ranges, the parameters defining the SS REF and GSCN are defined, for example, in the following table.

[0106]

Table 9

[0107] The synchronization rasters for each bandwidth are given, for example, by the table below. The distances between applicable GSCN entries are shown in the table below.<Step size> It is given by.

[0108] [Table 10]

[0109] The notes shown in Table 10 have the following meanings:

[0110] - NOTE 1: The SSB pattern is defined in 3GPP TS 38.213.

[0111] - NOTE 2: Available SS raster entries are GSCN={6432, 6443, 6457, 6468, 6479, 6493, 6507, 6518, 6532, 6543}

[0112] - NOTE 3: The following GSCNs are acceptable for operation within bandwidth n46: GSCN={8996, 9010, 9024, 9038, 9051, 9065, 9079, 9093, 9107, 9121, 9218, 9232, 9246, 9260, 9274, 9288, 9301, 9315, 9329, 9343, 9357, 9371, 9385, 9402, 9416, 9430, 9444, 9458, 9472, 9485, 9499, 9513}

[0113] - NOTE 4: The following GSCNs are acceptable for operation within bandwidth n96: GSCN={9548, 9562, 9576, 9590, 9603, 9617, 9631, 9645, 9659, 9673, 9687, 9701, 9714, 9728, 9742, 9756, 9770, 9784, 9798, 9812, 9826, 9840, 9853, 9867, 9881, 9895, 9909, 9923, 9937, 9951, 9964, 9978, 9992, 10006, 10020, 10034, 10048, 10062, 10076, 10090, 10103, 10117, 10131, 10145, 10159, 10173, 10187, 10201, 10214, 10228, 10242, 10256, 10270, 10284, 10298, 10312, 10325, 10339, 10353}

[0114] - NOTE 5: Available SS raster entries are GSCN=5032, 5043, 5054}

[0115] - NOTE 6: Available SS raster entries are GSCN={4707, 4715, 4718, 4729, 4732, 4743, 4747, 4754, 4761, 4768, 4772, 4782, 4786, 4793}

[0116] Referring to Tables 9 and 10, for n35, the UE can perform cell searches while increasing GSCN=6125 by 1 each time.

[0117] Cell selection is performed based on the cell-defining SSB (CD-SSB) where the synchronous raster is located. The SSB is referred to as a CD-SSB if it is associated with remaining minimum system information (RMSI) (e.g., SIB1), for example, if the MIB carried by the PBCH within the SSB contains parameters for the transmission of the PDCCH that schedules the RMSI. The UE can explore the frequency band and identify the strongest cell based on the SSB for each carrier frequency, and can select the cell to perform the initial connection.

[0118] Figure 9 illustrates a situation where terrestrial networks (TN) and non-terrestrial networks (NTN) coexist.

[0119] Referring to Figure 9, when a UE is serviced by a TN BS, the UE reception (RX) beam is directed towards the ground, and when a UE is serviced by an NTN BS, the UE RX beam is directed towards the sky. For frequency bands in which NTN and TN can coexist, the UE has no prior information about the BS type during the initial connection. In this case, during the initial connection, the UE does not know whether its RX beam for SSB reception should be formed toward a TN-BS or an NTN-BS, so the UE will arbitrarily select the RX beam direction. If the arbitrarily selected RX beam direction is inappropriate, performance degradation may occur because cell search will take more time. Therefore, a method for distinguishing between NTN and TN is required for coexistence. The implementation of this specification for distinguishing between NTN and TN based on SSB structure will be described below.

[0120] Figure 10 illustrates an SSB structure transmitted by BS.

[0121] Referring to Figure 10, the SSB transmitted by BS consists of PSS and SSS, each occupying one OFDM symbol and 127 subcarriers, and PBCH, which spans across three OFDM symbols and 240 subcarriers but leaves an unused portion in the middle for SSB on one OFDM symbol.

[0122] Furthermore, considering that the requirements for direct communication between UEs differ from those for communication between BSs and UEs, the sidelink SS and sidelink PBCH transmitted by the UE have a different structure from the SSB transmitted by the BS. For example, the sidelink synchronization signal transmitted by the UE consists of a sidelink PSS (S-PSS) and a sidelink SSS (S-SSS), each occupying two OFDM symbols and 127 subcarriers. The physical sidelink broadcast channel (PSBCH) includes the associated DM-RS and occupies nine and seven OFDM symbols respectively for the regular and extended CP cases.

[0123] In the case of NTN, since SSB is transmitted by a satellite-based satellite-based satellite, the requirements for NTN SSB and TN SSB will likely be the same. Therefore, in some implementations of this specification, it can be assumed that the same form of SSB transmitted to NTN as the SSB transmitted to TN by the satellite-based satellite is also transmitted to NTN.

[0124] Figure 11 illustrates some of the SSB reception processes involved in several implementations of this specification.

[0125] A UE attempting SSB detection (for cell search for cell selection / re-selection), or performing SSB monitoring for connected or configured serving cells, may attempt SSB detection under a Type A SSB assumption (e.g., legacy SSB (see Figure 6 and Table 3)) for operating bands that support only TN (S1101, Yes) (S1103a), and under an SSB assumption relating to some implementations of this specification (hereinafter, Type B SSB assumption) for operating bands where NTN and TN coexist (S1101, No) (S1103b). For example, in the case of frequency bands that support the coexistence of NTN and TN, the UE may assume a legacy SSB pattern or a new SSB pattern relating to some implementations of this specification. In some implementations of this specification, for candidate SSBs for TN among the candidate SSBs using the new SSB pattern, monitoring can be performed with the UE Rx beam(s) directed toward the ground, and for candidate SSBs for NTN among the candidate SSBs using the new SSB pattern, monitoring can be performed with the UE Rx beam(s) directed toward the sky.

[0126] Figure 12 illustrates the NTN / TN distinction in some implementations of this specification.

[0127] > Alt 1. NTN-specific SSB and TN-specific SSB can be distinguished by different synchronization rasters. For example, a TN-specific synchronization raster and an NTN-specific synchronization raster are defined. The UE can attempt SSB detection using the UE Rx beam(s) pointed towards the ground for the TN-specific synchronization raster, and use the UE Rx beam(s) pointed towards the air for the NTN-specific synchronization raster.

[0128] >> Alt 1-1. Synchronized rasters are defined for NTN and TN in different ranges of GSCN. Referring to Figure 12(a), different initial GSCNs are defined for NTN and TN respectively for the same operating bandwidth, and synchronized rasters can be defined with step sizes increasing by N. Referring to Table 10, for example, for an operating bandwidth n40, 5762- <2> -5989 is defined as the GSCN range, and 5763- is designated for NTN. <2> The GSCN range of -5989 is defined as the synchronous raster. In some implementations, it is defined for each operating bandwidth as exemplified in Table 10.<Step size> Twice that is due to Alt 1-1<Step size> It can be used as such.

[0129] >> Alt 1-2. Synchronized rasters for NTN (candidate) SSB (multiple possible) and synchronized rasters for TN (candidate) SSB (multiple possible) can be distinguished by even / odd GSCN. For example, referring to Figure 12(b), it can be specified that TN uses a synchronized raster defined in an even (or odd) GSCN, and NTN uses a synchronized raster defined in an odd (or even) GSCN.

[0130] >> Alt 1-3. Synchronized rasters for NTN (candidate) SSB (multiple possible) and TN (candidate) SSB (multiple possible) can use lower (or upper) GSCNs and upper (or lower) GSCNs. For example, referring to Figure 12(c), it can be specified that TN uses a synchronized raster defined in the GSCN belonging to the first half of the GSCN of the operating bandwidth, and NTN uses a synchronized raster defined in the GSCN belonging to the remaining half of the GSCN of the said operating bandwidth. Referring to Table 10, for example, 5672- for operating bandwidth n40 <1> Of the GSCN range of -5989 <5762> - <1> The GSCN range of -5875 is used for TN. <5876> - <1> The GSCN range -5989 can be specified as being used for NTN.

[0131] Figures 13 and 14 illustrate the NTN / TN distinction according to other realizations of this specification. In particular, Figures 13 and 14 illustrate some realizations of this specification that distinguish NTN / TN using different SSB (timing) patterns.

[0132] > Alt 2-1.SSB-level association

[0133] Each (candidate) SSB (timing) within an SS burst can be defined to be associated with NTN or TN. For example, each (candidate) SSB (timing) within an SS burst is associated with NTN or TN according to one of the following. The UE can attempt SSB detection using UE Rx beam(s) facing the ground for candidate SSB timings (multiple possible) for TN, and attempt SSB detection using UE Rx beam(s) facing the sky for candidate SSB timings (multiple possible) for NTN.

[0134] In some realizations, the gap T between the SSB for TN and the SSB for NTN gap is designed to be larger than the beam switching delay T switch required for beam switching.

[0135] In some realizations, the time gap between SSBs transmitted at different times can be designed to have different values depending on whether the SSB is associated with TN or NTN. For example, the gap between SSBs for TN is T gap,1 and the gap between SSBs for NTN is T gap,2 and the gap between an SSB for TN and an SSB for NTN is T gap,3 are designed as such. At this time, the time gaps T gap,1 , T gap,2 , T gap,3 are the beam switching delays required in their respective situations, for example T switch,1 , T switch,2 , T switch,3Each of these factors can be taken into consideration when designing.

[0136] >> Alt 2-1-1. Each (candidate) SSB (timing) within an SS burst is associated with either NTN or TN based on its odd / even candidate SSB index. For example, referring to Figure 13(a), a (candidate) SSB (timing) with an even candidate SSB index can be designated for TN, and a (candidate) SSB (timing) with an odd candidate SSB index can be designated for NTN. Or, the reverse may be applied.

[0137] >> Alt 2-1-2. Each (candidate) SSB (timing) within an SS burst is associated with NTN or TN based on the consecutive SSB portion. For example, referring to Figure 13(a), L within an SSB burst max The first L among the (candidate) SSBs max / Two consecutive (candidate) SSBs are for TN, the remaining L max Two consecutive (candidate) SSBs can be specified for NTN use. Alternatively, they may be specified in reverse.

[0138] > Alt 2-2.SS Burst - Level Related

[0139] Each SS burst is associated with either NTN or TN. During the period for TN SS bursts, the UE may attempt SSB detection using UE Rx beams directed towards the ground, and during the period for NTN SS bursts, it may attempt SSB detection using UE Rx beams directed towards the air.

[0140] >> Alt 2-2-1. SS bursts appear at predetermined intervals, but SS burst associations can be defined for each interval. For example, in the case of a frequency band defined so that SS bursts are transmitted at a period of P ms, referring to Figure 14(a), the SS burst timing corresponding to the aforementioned interval is associated with TN, and the second SS burst timing is associated with NTN, so that SS bursts associated with TN and SS bursts associated with NTN appear alternately. In this case, the TN SS burst and the NTN SS burst will each be transmitted at 2*P ms on the aforementioned frequency band.

[0141] >> Alt 2-2-2. Referring to Figure 10, the SS burst in the first half-frame of a frame can be specified to be associated with TN, and the SS burst in the second half-frame of the same frame can be specified to be associated with NTN. Or, it may be specified the other way around. Referring to Figure 14(b), a half-frame with an SS burst for TN and another half-frame with an SS burst for NTN can be transmitted with a period of P ms.

[0142] Figure 15 illustrates an example of the NTN / TN distinction in other implementations of this specification.

[0143] > Alt 3. Use of different SSB transmission cycles

[0144] Two different SSB transmission periods can be defined for TN and NTN. In Figure 15, T p TN This indicates the SSB period for TN, T p NTN This indicates the SSB period for NTN. When different SSB transmission periods are used for TN and NTN, the SSB timings for TN and NTN may or may not overlap. If the SSB timings for TN and NTN overlap in time, the following can be considered.

[0145] >> Alt 3-1.TN can be prioritized. Referring to Figure 15, the UE can prioritize the SSB for TN and attempt SSB detection when the timings overlap. For example, if the SSB timing of TN and NTN overlap in time, the UE can attempt SSB detection using the UE Rx beam(s) directed towards the ground.

[0146] >> Alt 3-2. NTN can be prioritized. Referring to Figure 15, the UE can prioritize the NTN SSB and attempt SSB detection in the event of overlapping timings. For example, if the TN SSB timing and the NTN SSB timing overlap in time, the UE can attempt SSB detection using the UE Rx beam(s) directed into the air.

[0147] >> It's possible that the implementation of Alt 3-3.UE will be left to others.

[0148] A UE performing an initial cell (re)search does not know the half-frame boundary of the cell until it detects an SSB on the cell, and can therefore attempt SSB detection by randomly switching the UE Rx beam. The UE can then learn the half-frame boundary after an SSB is detected for a particular UE Rx beam, and can subsequently perform beam refinement to determine a more accurate UE Rx beam. According to Alt 1 described above, the UE can clearly distinguish between TN BS transmission beams and NTN BS transmission beams using a synchronous raster, and can clearly distinguish between TN UE receiving beams and NTN UE receiving beams, or attempt to receive SSB(s) together. Regarding some implementations of Alt 2 or Alt 3 described above, the UE can attempt SSB detection by randomly changing the UE Rx beam(s) while considering the expected SSB(timing) pattern until it acquires the frame boundary.

[0149] In some implementations of this specification, the UE can detect an SSB and obtain an MIB from the received PBCH, and from the received MIB, it can also explicitly obtain information about whether it is TN or NTN as part of the information about the cell associated with the currently detected SSB.

[0150] In TN (Telescope Networks), due to the diverse terrain and features on the ground, there can be a variety of LOS (line-of-sight) and NLOS (non-line-of-sight) paths that the downlink signal may take, requiring the BS (Bridge System) to use a variety of beams to transmit SSB (Solid State Bus). In contrast, in NTN (Non-Telescope Networks), communication services are provided to ground-based UEs (Underground Users) by aerial BS, so the number of possible paths that the downlink signal may take may be smaller compared to a TN environment. Therefore, NTN may require fewer BS TX beams than TN for adequate communication services. Accordingly, in some implementations of this specification described above, the maximum number of candidate SSBs for TN within each SS burst (referred to as an SSB (timing) pattern) L max_TN and the maximum number of candidate SSBs for NTN L max_NTN They may differ.

[0151] In some implementations of this specification, transmitting a signal / channel in a transmission beam (UE or BS) can be expressed as transmitting the signal / channel in a spatial domain transmission filter. In some implementations of this specification, receiving a signal / channel in a reception beam (UE or BS) can be expressed as receiving the signal / channel using a spatial domain reception filter. For example, transmission using the same transmission beam may mean transmission using the same spatial domain transmission filter, and reception using the same reception beam may mean reception using the same spatial domain reception filter.

[0152] Figure 16 illustrates some of the downlink reception flows involved in several implementations of this specification.

[0153] A UE can perform some of the implementations of this specification with respect to the reception of downlink signals. A UE may include at least one transceiver; at least one processor; and at least one computer memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform some of the implementations of this specification. A processing device for a UE may include at least one processor; and at least one computer memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform some of the implementations of this specification. A computer-readable (non-temporary) storage medium may store at least one computer program that, when executed by the at least one processor, includes instructions that cause the at least one processor to perform some of the implementations of this specification. A computer program or computer program product may be recorded on at least one computer-readable (non-temporary) storage medium and, when executed, include instructions that cause (at least one processor) to perform some of the implementations of this specification. In the UE, the processing device, the computer-readable (non-temporary) storage medium, and / or the computer program product, the operation may include: attempting to detect a synchronization block (SSB) on a first frequency band supporting a terrestrial network (TN) and a non-terrestrial network (NTN) (S1601); and, based on the detection of the SSB on the cell, obtaining time and frequency synchronization with the cell (S1603). In some implementations, the UE may transmit a physical random access channel (PRACH) based on the SSB.Attempting SSB detection on the first frequency band includes: attempting SSB detection based on a first SSB timing pattern defined for the TN; and attempting SSB detection based on a second SSB timing pattern defined for the NTN, wherein the second SSB timing pattern may contain fewer SSB timings than the number of SSB timings in the first SSB timing pattern (S1603). The first SSB timing pattern may correspond to a set of SSBs for the TN in a half-frame or SS burst, an SS burst for the TN, or an SSB period for the TN, as described in Alt 1 to Alt 3.

[0154] In some implementations, attempting SSB detection based on the first SSB timing pattern can be performed in a synchronous raster defined for the TN. In some implementations, attempting SSB detection based on the second SSB timing pattern can be performed in a synchronous raster defined for the NTN.

[0155] In some implementations, each SSB timing in the first SSB timing pattern and the second SSB timing pattern can correspond to a (candidate) SSB (or (candidate) SSB index) in a synchronization signal (SS) burst transmitted at a predetermined period.

[0156] In some implementations, the SSB timing in the first SSB timing pattern is associated, respectively, with a (candidate) SSB (or (candidate) SSB index) in a first synchronization signal (SS) burst, and the SSB timing in the second SSB timing pattern is associated, respectively, with a (candidate) SSB (or (candidate) SSB index) in a second SS burst. In some implementations, the second SS bursts may exist in different half-frames.

[0157] In some implementations, the first SSB timing pattern may appear in the first period, and the second SSB timing pattern may appear in the second period, which is longer than the first period.

[0158] In some implementations, the operation may include: attempting SSB detection based on a third SSB timing pattern defined for TN on a second frequency band that does not support NTN.

[0159] Figure 17 illustrates some of the downlink transmission flows involved in several implementations of this specification.

[0160] A BS can perform some of the operations relating to the implementations of this specification with respect to the transmission of downlink signals. A BS may include at least one transceiver; at least one processor; and at least one computer memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform some of the operations relating to this specification. A processing device for a BS may include at least one processor; and at least one computer memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform some of the operations relating to this specification. A computer-readable (non-temporary) storage medium may store at least one computer program that, when executed by the at least one processor, includes instructions that cause the at least one processor to perform some of the operations relating to this specification. A computer program or computer program product may be recorded on at least one computer-readable (non-temporary) storage medium and, when executed, include instructions that cause (at least one processor) to perform some of the operations relating to this specification. In the BS, the processing device, the computer-readable (non-temporary) storage medium, and / or the computer program product, the operation may include: if the BS is a TN BS (S1701, Yes), transmitting the SSB over the cell according to an SSB timing pattern defined for TN according to some implementations herein (see Synchronized Raster for TN, SSB for TN, SS Burst for TN, SSB Period for TN, etc., as described in Alt 1 to Alt 3) (S1703a).The operation described above can transmit SSB over the cell according to an SSB timing pattern defined for NTN according to some implementations of this specification (see Synchronous Raster for NTN, SSB for NTN, SS Burst for NTN, SSB Period for NTN, etc., as described in Alt 1 to Alt 3) if the BS is an NTN BS (S1701, No).

[0161] As described above, the examples disclosed herein are provided so that a person of ordinary skill in the art relating to this specification can embody and implement this specification. While the examples of this specification have been used as a reference above, a person of ordinary skill in the art will understand that these examples can be modified and altered in various ways. Therefore, this specification is not limited to the examples provided herein, but seeks to provide the broadest possible scope consistent with the principles and novel features disclosed herein.

[0162] The implementation of this specification can be used in BS, UE, or other equipment in wireless communication systems.

Claims

1. In a wireless communication system, this refers to the user device receiving a downlink signal. Attempting to detect synchronization blocks (SSB) on a first frequency band supporting terrestrial networks (TN) and non-terrestrial networks (NTN); Based on the detection of SSB on the cell, to obtain time and frequency synchronization with the cell; and This includes transmitting a physical random access channel (PRACH) based on the aforementioned SSB, Attempting to detect the SSB on the first frequency band is: Attempting SSB detection based on a first SSB timing pattern defined for the aforementioned TN; and This includes attempting SSB detection based on a second SSB timing pattern defined for the aforementioned NTN, The second SSB timing pattern includes fewer SSB timings than the number of SSB timings in the first SSB timing pattern. Method for receiving downlink signals.

2. Attempting SSB detection based on the first SSB timing pattern is performed in a synchronous raster defined for the TN, Attempting SSB detection based on the second SSB timing pattern is performed in the synchronous raster defined for the NTN. The method for receiving a downlink signal according to claim 1.

3. Each SSB timing in the first SSB timing pattern and the second SSB timing pattern corresponds to an SSB in a synchronization signal (SS) burst transmitted at a predetermined period. The method for receiving a downlink signal according to claim 1.

4. The SSB timing in the first SSB timing pattern is appropriately associated with the SSB in the first synchronization signal (SS) burst. The SSB timings within the second SSB timing pattern are respectively associated with the SSBs within the second SSB burst. The aforementioned second SS burst and the aforementioned second SS burst exist in different half-frames. The method for receiving a downlink signal according to claim 1.

5. The first SSB timing pattern appears in the first cycle. The second SSB timing pattern appears in a second period that is longer than the first period. The method for receiving a downlink signal according to claim 1.

6. This includes attempting SSB detection based on a third SSB timing pattern on a second frequency band that does not support the aforementioned NTN, The method for receiving a downlink signal according to claim 1.

7. In a wireless communication system, a user device receives a downlink signal. At least one transceiver; At least one processor; and It includes at least one computer memory that is operablely connected to the at least one processor and, when executed, stores instructions that cause the at least one processor to perform an operation, The aforementioned operation is: Attempting to detect synchronization blocks (SSB) on a first frequency band supporting terrestrial networks (TN) and non-terrestrial networks (NTN); Based on the detection of SSB on the cell, to obtain time and frequency synchronization with the cell; and This includes transmitting a physical random access channel (PRACH) based on the aforementioned SSB, Attempting to detect the SSB on the first frequency band is: Attempting SSB detection based on a first SSB timing pattern defined for the aforementioned TN; and This includes attempting SSB detection based on a second SSB timing pattern defined for the aforementioned NTN, The second SSB timing pattern includes fewer SSB timings than the number of SSB timings in the first SSB timing pattern. User equipment.

8. A processing device in a wireless communication system, At least one processor; and It includes at least one computer memory that is operablely connected to the at least one processor and, when executed, stores instructions that cause the at least one processor to perform an operation, The aforementioned operation is: Attempting to detect synchronization blocks (SSB) on a first frequency band supporting terrestrial networks (TN) and non-terrestrial networks (NTN); Based on the detection of SSB on the cell, to obtain time and frequency synchronization with the cell; and This includes transmitting a physical random access channel (PRACH) based on the aforementioned SSB, Attempting to detect the SSB on the first frequency band is: Attempting SSB detection based on a first SSB timing pattern defined for the aforementioned TN; and This includes attempting SSB detection based on a second SSB timing pattern defined for the aforementioned NTN, The second SSB timing pattern includes fewer SSB timings than the number of SSB timings in the first SSB timing pattern. Processing device.

9. A computer-readable storage medium, The storage medium stores at least one program code that, when executed, causes at least one processor to perform an action, and the action is: Attempting to detect synchronization blocks (SSB) on a first frequency band supporting terrestrial networks (TN) and non-terrestrial networks (NTN); Based on the detection of SSB on the cell, to obtain time and frequency synchronization with the cell; and This includes transmitting a physical random access channel (PRACH) based on the aforementioned SSB, Attempting to detect the SSB on the first frequency band is: Attempting SSB detection based on a first SSB timing pattern defined for the aforementioned TN; and This includes attempting SSB detection based on a second SSB timing pattern defined for the aforementioned NTN, The second SSB timing pattern includes fewer SSB timings than the number of SSB timings in the first SSB timing pattern. Memory media.

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