Method and apparatus for transmitting or receiving low power-synchronization signal group in wireless communication system

Abstract

Disclosed are a method and apparatus for transmitting or receiving a low power-synchronization signal (LP-SS) group in a wireless communication system. The method according to an embodiment of the present disclosure may comprise the steps of: receiving, by a terminal, one or more first synchronization signals (SSs) from a network within a first time interval; and receiving, by the terminal, one or more second synchronization signals (SSs) from the network within a second time interval. A resource location of one or more of the second time interval or the one or more second SSs may be on the basis of a resource location of one or more of the first time interval or the one or more first SSs.

Description

Method and device for transmitting or receiving a low-power synchronization signal group in a wireless communication system

[0001] The present disclosure relates to a wireless communication system, and more particularly, to a method and apparatus for transmitting or receiving a low power-synchronization signal (LP-SS) group in a wireless communication system.

[0002] The fifth generation (5G) wireless communication system, the successor to 4G LTE (long-term evolution), is a new, clean-slate mobile communication system characterized by high performance, low latency, and high availability. 5G NR (New Radio) can utilize all available spectrum resources, from low-frequency bands below 1 GHz, to intermediate-frequency bands between 1 GHz and 10 GHz, and to high-frequency (or millimeter wave) bands above 24 GHz. 6G wireless communication systems are being developed based on the underlying technologies of 5G wireless communication.

[0003] The 6G wireless communication system is being developed with the goals of (i) very high data rates per device, (ii) a very large number of connected devices, (iii) global connectivity, (iv) very low latency, (v) reduced energy consumption of 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. Considering the requirements of the 6G system, such as a peak data rate of 1 Tbps per device, an end-to-end latency of 1 ms, a maximum spectrum efficiency of 100 bps / Hz, support for mobility of 1000 km / h, satellite integration, artificial intelligence (AI), autonomous vehicles, extended reality (XR), and haptic communication, various technologies are being researched.

[0004] The technical problem of the present disclosure is to provide a method and device for transmitting or receiving a low power-synchronization signal (LP-SS) group based on reference time / frequency resources in a wireless communication system.

[0005] The technical problems to be achieved in the present disclosure are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present disclosure belongs from the description below.

[0006] A method according to one aspect of the present disclosure may include the steps of: receiving, by a terminal, one or more first synchronization signals (SS) from a network within a first time interval; and receiving, by the terminal, one or more second synchronization signals (SS) from the network within a second time interval. A resource location of one or more of the second time intervals or the one or more second SSs may be based on a resource location of one or more of the first time intervals or the one or more first SSs.

[0007] A method according to an additional aspect of the present disclosure may include the steps of: transmitting, by a base station, one or more first synchronization signals (SS) to a terminal within a first time interval; and transmitting, by the base station, one or more second synchronization signals (SS) to the terminal within a second time interval. A resource location of one or more of the second time intervals or one or more of the second SSs may be based on a resource location of one or more of the first time intervals or one or more of the first SSs.

[0008] According to the present disclosure, a method and device for transmitting or receiving a low power-synchronization signal (LP-SS) group based on reference time / frequency resources in a wireless communication system can be provided.

[0009] The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects that are not mentioned will be clearly understood by a person having ordinary skill in the art to which the present disclosure pertains from the description below.

[0010] The accompanying drawings, which are incorporated in and are part of the detailed description to aid in understanding the present disclosure, provide embodiments of the present disclosure and, together with the detailed description, describe the technical features of the present disclosure.

[0011] Figure 1 illustrates a flexible network topology to which some examples of the present disclosure may be applied.

[0012] FIG. 2 illustrates an example of a communication system to which some examples of the present disclosure may be applied.

[0013] FIG. 3 illustrates an example of a wireless device to which some examples of the present disclosure may be applied.

[0014] FIG. 4 exemplarily illustrates a communication procedure between a first node and a second node to which some examples of the present disclosure may be applied.

[0015] FIG. 5 illustrates a functional framework for AI operations to which some examples of the present disclosure may be applied.

[0016] FIG. 6 illustrates an example of operations related to AI model training and AI model inference to which some examples of the present disclosure may be applied.

[0017] FIG. 7 illustrates another example of operations related to AI model training and AI model inference to which some examples of the present disclosure may be applied.

[0018] FIG. 8 illustrates another example of operations related to AI model training and AI model inference to which some examples of the present disclosure may be applied.

[0019] FIG. 9 illustrates an electromagnetic spectrum to which some examples of the present disclosure may be applied.

[0020] FIG. 10 illustrates an example of a system information transmission / reception procedure to which some examples of the present disclosure may be applied.

[0021] FIG. 11 exemplarily illustrates a beam management procedure to which some examples of the present disclosure may be applied.

[0022] Figures 12 and 13 illustrate examples of NTN scenarios to which some examples of the present disclosure may be applied.

[0023] FIG. 14 illustrates examples of sensing operations to which some examples of the present disclosure may be applied.

[0024] FIG. 15 and FIG. 16 are diagrams for explaining examples of the OOK method for an LP signal according to the present disclosure.

[0025] FIG. 17 is a diagram illustrating an example of an SSB time resource to which the present disclosure can be applied.

[0026] FIG. 18 is a drawing for explaining an example of a method performed by a terminal according to the present disclosure.

[0027] FIG. 19 is a drawing illustrating an example of a method performed by a base station according to the present disclosure.

[0028] FIG. 20 is a diagram illustrating an example of signaling between a base station and a terminal according to the present disclosure.

[0029] FIG. 21 is a diagram illustrating an example of a slot offset and a start symbol offset between an SSB burst and an LP-SS group according to the present disclosure.

[0030] FIG. 22 is a diagram showing an example of an SSB offset between an SSB burst and an LP-SS group and a symbol offset between LP-SSs according to the present disclosure.

[0031] FIG. 23 is a diagram showing an example of a frequency offset and a time offset between an SSB burst and an LP-SS group according to the present disclosure.

[0032] FIG. 24 is a diagram illustrating an example of a slot offset, a start symbol offset, and a symbol offset between LP-SS groups and an SSB burst according to the present disclosure.

[0033] FIG. 25 is a diagram showing an example of slot offsets between SSB bursts and LP-SS groups according to the present disclosure, and time offsets for each LP-SS.

[0034] FIG. 26 is a diagram showing an example of a time offset for each LP-SS within an LP-SS group according to the present disclosure.

[0035] FIG. 27 is a diagram illustrating an example of a time offset from an associated SSB for each LP-SS within an LP-SS group according to the present disclosure.

[0036] FIG. 28 is a diagram illustrating an example of a time offset for an LP-SS group and an LP-SS based on a reference rather than an SSB burst according to the present disclosure.

[0037] FIG. 29 is a diagram illustrating another example of a time offset for an LP-SS group and an LP-SS based on a reference other than an SSB burst according to the present disclosure.

[0038] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description set forth below, together with the accompanying drawings, is intended to explain exemplary embodiments of the present disclosure and is not intended to represent the only embodiments in which the present disclosure may be practiced. The following detailed description includes specific details to provide a thorough understanding of the present disclosure. However, one of ordinary skill in the art will appreciate that the present disclosure may be practiced without these specific details.

[0039] In some cases, to avoid obscuring the concepts of the present disclosure, known structures and devices may be omitted or illustrated in block diagram form focusing on the core functions of each structure and device.

[0040] In the present disclosure, when a component is said to be "connected," "coupled," or "connected" to another component, this may include not only a direct connection but also an indirect connection in which another component exists between them. Furthermore, the terms "comprises" or "has" in the present disclosure specify the presence of the mentioned features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0041] In this disclosure, terms such as “first,” “second,” etc. are used only to distinguish one component from another and are not used to limit the components, and do not limit the order or importance between the components unless specifically stated otherwise. Accordingly, within the scope of this disclosure, a first component in one embodiment 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.

[0042] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to limit the scope of the claims. As used in the description of the embodiments and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise.

[0043] In this disclosure, "A or B" can mean "only A," "only B," or "both A and B." In other words, "A or B" in this disclosure can be interpreted as "A and / or B." For example, "A, B or C" in this disclosure can mean "only A," "only B," "only C," or "any combination of A, B and C."

[0044] As used herein, a slash ( / ) or a comma may mean "and / or." For example, "A / B" may mean "A and / or B." Accordingly, "A / B" may mean "only A," "only B," or "both A and B." For example, "A, B, C" may mean "A, B, or C."

[0045] In the present disclosure, “at least one of A and B” may mean “only A,” “only B,” or “both A and B.” Additionally, in the present disclosure, 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.”

[0046] Additionally, in the present disclosure, “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.”

[0047] Additionally, parentheses used in the present disclosure may mean "for example." Specifically, when indicated as "control information (PDCCH)", "PDCCH" may be described as an example of "control information." In other words, "control information" in the present disclosure is not limited to "PDCCH," and "PDCCH" may be described as an example of "control information." Furthermore, even when indicated as "control information (i.e., PDCCH)", "PDCCH" may be described as an example of "control information."

[0048] In the following description, 'when, if, in case of' can be replaced with 'based on'.

[0049] Technical features individually described in one drawing in this disclosure may be implemented individually or simultaneously.

[0050] In the present disclosure, a terminal or user equipment (UE) may be a portable device and may be a first node that receives a signal from a base station / second node / IAB (integrated access backhaul) node.

[0051] In the present disclosure, a base station (BS) may be a second node / IAB node / Transmission-Reception Point (TRP).

[0052] In the present disclosure, higher layer parameters may be parameters configured, pre-configured, or pre-defined for the terminal. For example, a base station or a network may transmit higher layer parameters to the terminal. For example, the higher layer parameters may be transmitted via radio resource control (RRC) signaling or medium access control (MAC) signaling.

[0053] In the present disclosure, "setting or defining" may be interpreted as being set to a device through predefined signaling (e.g., SIB (system information block), MAC, RRC) from a base station or network. In the present disclosure, "setting or defining" may be interpreted as being set to a device through separate signaling or being defined in advance without separate signaling.

[0054] In the present disclosure, transmitting or receiving a channel means transmitting or receiving information or a signal through the channel. For example, transmitting a control channel means transmitting control information or a signal through the control channel. Similarly, transmitting a data channel means transmitting data information or a signal through the data channel.

[0055] The technology described in the present disclosure 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), 5G NR, and the like.

[0056] The technology described in the present disclosure 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.

[0057] Network structure

[0058] Figure 1 illustrates a flexible network topology to which some examples of the present disclosure may be applied.

[0059] 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 integrated access backhaul (IAB) nodes, relays, and radio frequency (RF) repeaters, as illustrated in Figure 1, may be applied, or a non-terrestrial network (NTN) 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, and 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, or in the case of a network-controlled repeater, it may not only amplify and forward signals but also adjust its transmission and reception settings based on information provided by the network. For example, NTN nodes could be satellites or aircraft that provide NTN coverage that terrestrial networks struggle to provide. Beyond these examples, various intermediate points can be introduced to improve the network topology.

[0060] 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.

[0061] 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. For example, 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.

[0062] In some examples of the present disclosure, the description of a terminal may equally apply 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 the present disclosure, the description of a base station may equally apply 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. In most cases where there is no additional description of the operations of three or more entities, the communicating entities in the present disclosure are briefly described as terminals and / or base stations (or first nodes and / or second nodes), where 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.

[0063] As such, in some examples of the present disclosure, for the sake of simplicity of explanation, the subjects of the operation may be referred to as terminals and / or base stations (or first nodes and / or second nodes). In addition, the terms terminal and / or base station (or first node and / or second node) may also be interpreted / replaced as in the following examples: For example, the terminal (or first node) and the base station (or 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.

[0064] In the present disclosure, there may be zero or more intermediate points between the base station and the terminal. If an intermediate point exists, it may correspond to an IAB node / relay / RF repeater / NTN node, or a node supporting other functions. The intermediate point may be a node with a fixed location or a node with an unfixed location.

[0065] Systems applicable to this disclosure

[0066] FIG. 2 illustrates an example of a communication system to which some examples of the present disclosure may be applied.

[0067] The communication system (100) applied to the present disclosure 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, 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).

[0068] 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, an IoT device (110f) (e.g., a sensor) can communicate directly with another IoT device (e.g., a sensor) or another wireless device (110a to 110f).

[0069] 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.

[0070] Device applicable to the present disclosure

[0071] FIG. 3 illustrates an example of a wireless device to which some examples of the present disclosure may be applied.

[0072] 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).

[0073] 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.

[0074] 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) comprising 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.

[0075] 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.

[0076] 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.

[0077] 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. Additionally, 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 operational flowcharts disclosed in this document via 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 user data, control information, wireless signals / channels, etc. processed by at least one processor (202) from a baseband signal to an RF band signal. For this purpose, at least one transceiver (206) may include an (analog) oscillator and / or filter.

[0078] 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).

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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. 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 backhaul communications, and a wired transceiver may not be included.

[0086] Communication procedures

[0087] FIG. 4 exemplarily illustrates a communication procedure between a first node and a second node to which some examples of the present disclosure may be applied.

[0088] FIG. 4 illustrates operations of a first node (110) (e.g., a terminal) and a second node (120) (e.g., a base station) transmitting and / or receiving data and operations performed prior thereto.

[0089] In step S101, the first node (110) and the second node (120) can perform synchronization. For example, the terminal (110) performs an initial cell search operation. Specifically, the terminal (110) can detect at least one synchronization signal transmitted from the base station (120) according to a predefined rule. Here, the synchronization signal can include a plurality of synchronization signals (e.g., a primary synchronization signal, a secondary synchronization signal) classified according to a structure or purpose. Through this, the terminal (110) can confirm the boundaries of the frame, subframe, slot, and / or symbol of the base station (120) and obtain information (e.g., a cell identifier) ​​about the base station (120).

[0090] In step S103, the first node (110) can obtain system information transmitted from the second node (120). For example, 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., the channel used, whether it is provided in an on-demand manner), etc., and can be classified into, for example, a master information block (MIB) and a system information block (SIB). If necessary, the terminal (110) can transmit a signal requesting system information before receiving the system information. Such requesting and providing of system information may be performed after a random access procedure described below.

[0091] In step S105, the first node (110) and the second node (120) can perform a random access procedure. For example, 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 a random access procedure based on information related to a random access channel of the base station (120) obtained through system information (e.g., channel position, channel structure, structure of a supported preamble, etc.). For example, the terminal (110) may transmit a preamble (e.g., message 1 (MSG1)) over a random access channel, receive a random access response (RAR) message (e.g., message 2 (MSG2)), transmit a message (e.g., message 3 (MSG3)) including information related to the terminal (110) (e.g., identification information) using scheduling information included in the RAR message to the base station (120), and receive a message for contention resolution and / or connection establishment (e.g., message 4 (MSG4)). As another example, MSG1 and MSG3 may be transmitted and received as one message (e.g., message A (MSG A)), or MSG2 and MSG4 may be transmitted and received as one message (e.g., message B (MSG B)).

[0092] In step S107, the first node (110) and the second node (120) can perform signaling of control information. For example, 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 transmission 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.

[0093] In step S109, the first node (110) and the second node (120) can transmit and / or receive data. For example, 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 information bits. For example, 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.

[0094] 6G system core technologies

[0095] As core implementation technologies of the 6G system, technologies such as artificial intelligence (AI), THz (terahertz) communication, optical wireless technology, free space optics (FSO) backhaul network, massive MIMO (multiple input multiple output) 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.

[0096] artificial intelligence

[0097] 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. 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.

[0098] FIG. 5 illustrates a functional framework for AI operations to which some examples of the present disclosure may be applied.

[0099] Below, to explain AI (or AI / ML (machine learning)) in more detail, the terms can be defined as follows.

[0100] - Data collection: Data collected from network nodes, management entities, or terminals as a basis for AI model training, data analysis, and inference.

[0101] - 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.

[0102] - 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.

[0103] - AI / ML inference: The process of making predictions or inducing decisions based on collected data and the AI ​​model using a trained AI model.

[0104] Referring to FIG. 5, the data collection function (10) is a function that collects input data and provides processed input data to the model training function (20) and the model inference function (30).

[0105] Examples of input data may include measurements from terminals or other network entities, feedback from actors, and output from AI models.

[0106] The data collection function (10) performs data preparation based on input data and provides input data processed through the data preparation. Here, the data collection function (10) does not perform data preparation specific to each AI algorithm (e.g., data pre-processing and cleaning, formatting, and transformation), but can perform data preparation common to all AI algorithms.

[0107] After the data preparation process is performed, the data collection function (10) may provide training data (11) to the model training function (20) and may provide inference data (12) to the model inference function (30). Here, the training data (11) may correspond to data required as input for the AI ​​model training function (20), and the inference data (12) may correspond to data required as input for the AI ​​model inference function (30).

[0108] The data collection function (10) may be performed by a single entity (e.g., a terminal, a RAN node, a network node, etc.), but may also be performed by multiple entities. In this case, training data (11) and inference data (12) may be provided to the model training function (20) and model inference function (30), respectively, from multiple entities.

[0109] The model training function (20) may correspond to a function that performs AI model training, validation, and testing, which can generate model performance metrics as part of the AI ​​model testing procedure. If necessary, the model training function (20) may also be responsible for data preparation (e.g., data pre-processing and cleaning, formatting, and transformation, etc.) based on training data (11) provided by the data collection function (10).

[0110] Here, model deployment / update (13) can be used to initially deploy a trained, validated and tested AI model to the model inference function (30) or to provide an updated model to the model inference function (30).

[0111] The model inference function (30) may correspond to a function that provides AI model inference output (16) (e.g., prediction or decision). If applicable, the model inference function (30) may provide model performance feedback (14) to the model training function (20). In addition, the model inference function (30) may also be responsible for data preparation (e.g., data pre-processing and cleaning, formatting and transformation, etc.) based on inference data (12) provided by the data collection function (10), if necessary.

[0112] Here, output (16) refers to the inference output of the AI ​​model generated by the model inference function (30), and the details of the inference output may vary depending on the use case.

[0113] Model performance feedback (14) can be used to monitor the performance of the AI ​​model, if available, and this feedback may be omitted.

[0114] An actor function (40) is a function that receives an output (16) from a model inference function (30) and triggers or performs a corresponding task / action. The actor function (40) can trigger tasks / actions for other entities (e.g., one or more terminals, one or more RAN nodes, one or more network nodes, etc.) or for itself.

[0115] Feedback (15) can be used to derive training data (11), inference data (12), or to monitor the performance of the AI ​​model, its impact on the network, etc.

[0116] Meanwhile, the definitions of training / validation / test in data sets used in AI / ML can be distinguished as follows.

[0117] - Training data: refers to a data set for learning a model.

[0118] - Validation data: This refers to a dataset used to validate a model that has already completed training. Validation data can typically be used to prevent overfitting of the training data set. It can also be used to select the best model among the various models learned during the training process. Therefore, validation can be considered a type of learning.

[0119] - Test data: This refers to the data set for final evaluation. This data is unrelated to learning.

[0120] For example, the training and validation data can be divided into an 8:2 or 7:3 ratio within the entire data set. Alternatively, the training data:validation data:test data can be divided into a 6:2:2 ratio within the entire data set.

[0121] The level of cooperation can be defined as follows depending on whether the base station and the terminal have capabilities for AI / ML functions, and variations due to combination of multiple levels or separation of any one level are also possible.

[0122] Category 0a: This category corresponds to a no-collaboration framework. In this case, AI / ML algorithms are purely implementation-based and may not require any changes to the wireless interface.

[0123] Category 0b: Frameworks that involve a wireless interface modified to fit efficient implementation-based AI / ML algorithms, but without collaboration.

[0124] Category 1: This category applies to cases where inter-node support is required to improve the AI / ML algorithms of each node. For example, this applies when a terminal receives support from a base station (for training, adaptation, etc.), and vice versa. At this level, model exchange between network nodes is not required.

[0125] Category 2: This applies to cases where joint ML tasks can be performed between terminals and base stations. This level requires exchange of AI / ML model commands or network nodes.

[0126] The functions exemplified in FIG. 5 above may be implemented in a RAN node (e.g., a base station, a TRP, a CU of a base station, etc.), a network node, an OAM (operation administration maintenance) of a network operator, or a terminal.

[0127] Alternatively, two or more entities, such as a RAN, a network node, a network operator's OAM, or a terminal, may cooperate to implement the functions illustrated in FIG. 5. For example, one entity may perform some of the functions of FIG. 5, and another entity may perform the remaining functions. In this way, since some of the functions illustrated in FIG. 5 are performed by a single entity (e.g., a terminal, a RAN node, a network node, etc.), the transmission / provision of data / information between each function may be omitted. For example, if the model training function (20) and the model inference function (30) are performed by the same entity, the transmission / provision of model deployment / update (13) and model performance feedback (14) may be omitted.

[0128] Alternatively, any one of the functions illustrated in FIG. 5 may be performed collaboratively by two or more entities, including a RAN, a network node, a network operator's OAM, or a terminal. This may be referred to as a split AI operation.

[0129] FIG. 6 illustrates an example of operations related to AI model training and AI model inference to which some examples of the present disclosure may be applied.

[0130] For example, the AI ​​model training function may be performed by a network node (e.g., a core network node, an OAM of a network operator, etc.), and the AI ​​model inference function may be performed by a RAN node (e.g., a base station, a TRP, a CU of a base station, etc.).

[0131] Step 1: RAN node 1 and RAN node 2 can transmit input data (e.g., training data) for AI model training to the network node. Here, RAN node 1 and RAN node 2 can also transmit data collected from the terminal (e.g., terminal measurements related to RSRP (reference signal received power), RSRQ (reference signal received quality), SINR (signal to interference-plus-noise ratio) of the serving cell and neighboring cells, terminal location, speed, etc.) to the network node.

[0132] Step 2: Network nodes can train AI models using the received training data.

[0133] Step 3: The network node may distribute / update the AI ​​model to RAN node 1 and / or RAN node 2. RAN node 1 (and / or RAN node 2) may also continue model training based on the received AI model.

[0134] For convenience of explanation, we assume that the AI ​​model is deployed / updated only to RAN node 1.

[0135] Step 4: RAN node 1 can receive input data (e.g., inference data) for AI model inference from the terminal and RAN node 2.

[0136] Step 5: RAN node 1 can perform AI model inference using the received inference data to generate output data (e.g., prediction or decision).

[0137] Step 6: If applicable, RAN node 1 may send model performance feedback to the network nodes.

[0138] Step 7: RAN node 1, RAN node 2, and the terminal (or 'RAN node 1 and the terminal', or 'RAN node 1 and RAN node 2') may perform actions based on the output data. For example, in the case of a load balancing operation, the terminal may move from RAN node 1 to RAN node 2.

[0139] Step 8: RAN node 1 and RAN node 2 can transmit feedback information to the network nodes.

[0140] FIG. 7 illustrates another example of operations related to AI model training and AI model inference to which some examples of the present disclosure may be applied.

[0141] For example, both AI model training functions and AI model inference functions can be performed by RAN nodes (e.g., base stations, TRPs, CUs of base stations, etc.).

[0142] Step 1: The terminal and RAN node 2 can transmit input data (e.g., training data) for AI model training to RAN node 1.

[0143] Step 2: RAN node 1 can train an AI model using the received training data.

[0144] Step 3: RAN node 1 can receive input data (e.g., inference data) for AI model inference from the terminal and RAN node 2.

[0145] Step 4: RAN node 1 can perform AI model inference using the received inference data to generate output data (e.g., prediction or decision).

[0146] Step 5: RAN node 1, RAN node 2, and the terminal (or 'RAN node 1 and the terminal', or 'RAN node 1 and RAN node 2') may perform actions based on the output data. For example, in the case of a load balancing operation, the terminal may move from RAN node 1 to RAN node 2.

[0147] Step 6: RAN node 2 may transmit feedback information to RAN node 1.

[0148] FIG. 8 illustrates another example of operations related to AI model training and AI model inference to which some examples of the present disclosure may be applied.

[0149] For example, the AI ​​model training function may be performed by a RAN node (e.g., a base station, a TRP, a CU of a base station, etc.), and the AI ​​model inference function may be performed by a terminal.

[0150] Step 1: The terminal may transmit input data (e.g., training data) for AI model training to the RAN node. Here, the RAN node may collect data (e.g., terminal measurements related to RSRP, RSRQ, SINR of the serving cell and neighboring cells, terminal location, speed, etc.) from various terminals and / or from other RAN nodes.

[0151] Step 2: RAN nodes can train AI models using the received training data.

[0152] Step 3: The RAN node can distribute / update the AI ​​model to the terminal. The terminal can also continue model training based on the received AI model.

[0153] Step 4: Input data (e.g., inference data) for AI model inference can be received from the terminal and RAN node (and / or from another terminal).

[0154] Step 5: The terminal can perform AI model inference using the received inference data to generate output data (e.g., prediction or decision).

[0155] Step 6: If applicable, the terminal may send model performance feedback to the RAN node.

[0156] Step 7: The terminal and RAN node can perform actions based on the output data.

[0157] Step 8: The terminal may transmit feedback information to the RAN node.

[0158] THz communication (terahertz communication)

[0159] Data transmission 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 (the 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 6G cellular capacity. 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.

[0160] FIG. 9 illustrates an electromagnetic spectrum to which some examples of the present disclosure may be applied.

[0161] Key characteristics of THz communications include (i) the widely available bandwidth to support very high data rates, and (ii) the high path loss at high frequencies (which necessitates highly directional antennas). The narrow beamwidths generated by highly directional antennas reduce interference. The small wavelength of THz signals allows for a significantly 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 technologies to overcome range limitations.

[0162] Transmitting system information (e.g., MIB) in a cell in the THz frequency band can be inefficient because the beam width in high-frequency bands narrows, requiring more beam sweeps to cover the entire cell area. This method is particularly inefficient when there are only a few users within the cell.

[0163] FIG. 10 illustrates an example of a system information transmission / reception procedure to which some examples of the present disclosure may be applied.

[0164] The example of Fig. 10 is applicable not only to THz communication environments but also to 6G communication environments where THz communication is not applicable. Furthermore, the procedure illustrated in Fig. 10 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 Fig. 10.

[0165] In step S1010, the second node (120) (e.g., base station) can transmit system information of cell #1 via cell #2. For example, the base station provides at least two cells, cell #1 uses a THz frequency band, and cell #2 uses a frequency band other than the THz frequency band. Here, the system information may include at least one of an SFN (system frame number), a PDCCH configuration for SIB1, cell barring, cell re-selection, and subcarrier spacing generated in a higher layer, and may include at least one of an SFN, a half frame indicator, and an SSB index (synchronization signal / PBCH (physical broadcast channel) block index) generated in a physical layer. For this purpose, as an example, cell #1 and cell #2 may have a relationship of a secondary cell and a primary cell.

[0166] At step S1030, the first node (110) (e.g., terminal) can acquire synchronization for cell #1. Synchronization can be acquired by detecting a synchronization signal. Typically, synchronization is acquired before receiving system information, but 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 terminal can acquire synchronization based on the system information. Alternatively, synchronization acquisition can be performed before step S1010.

[0167] At step S1050, the first node (110) may transmit a signal for accessing cell #1. For example, the signal may include a random access preamble. The structure of this signal and the resources (e.g., channels) for transmitting the signal may be identified through system information. Thereafter, at step S1070, the first node (110) and the second node (120) may perform an access procedure for cell #1 and communicate.

[0168] The procedure described with reference to FIG. 10 may be performed when the first node (110) initially connects to cell #1 of the second node (120). Alternatively, a similar procedure may be performed when the first node (110) hands over to cell #1 of the second node (120). 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 second node (120).

[0169] Communications in the THz band are expected to experience extremely severe path loss, and to overcome this, terminals and base stations may be required to use very 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 movement or movement of the terminals, frequent re-alignment is required, which can lead to link instability.

[0170] FIG. 11 exemplarily illustrates a beam management procedure to which some examples of the present disclosure may be applied.

[0171] Although FIG. 11 illustrates an example of a procedure for searching and / or selecting beams for THz communication, this procedure is not limited to a THz environment and can also be applied to a 6G communication environment where THz communication is not applied.

[0172] Here, beam may be interpreted as other terms having equivalent technical meanings that can distinguish beams, such as 'spatial domain filter', 'spatial domain transmit filter', 'spatial domain receive filter', reference signal (RS) resource that distinguishes beams, SSB index, etc.

[0173] In step S1110, the second node (120) (e.g., base station) can set resources for beam management to the first node (110) (e.g., terminal). 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 an existing downlink signal / channel 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 an existing downlink signal / channel (e.g., SSB, PDSCH (physical downlink shared channel), 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. For example, a signal transmitted based on a dedicated port defined / set for beam search can be included in the technical concept according to the present embodiment.

[0174] In step S1130, the second node (120) (e.g., base station) transmits measurement signals using a plurality of transmission beams. For example, the measurement signals may include at least one of a reference signal and a synchronization signal. At this time, the measurement signals may be transmitted as many times as the number of beams that require measurement, and may also be transmitted in a multi-beam transmission method that forms a plurality of beams simultaneously to reduce sweeping time. Here, the multi-beam transmission may be performed based on at least one of a multi-panel, a sub-array, and a true time delay (TTD).

[0175] In step S1050, a first node (110) (e.g., a terminal) may transmit a feedback signal to a second node (120) (e.g., a base station). The feedback signal may indicate at least one beam selected by the terminal. The terminal may select at least one preferred beam based on the measurement signals received in step S1030.

[0176] In step S1070, the first node (110) and the second node (120) can perform communication. For example, the second node (120) can perform transmission to the first node (110) using the reception beam of the first node (110) selected in step S1050. If channel reciprocity is established, the transmission beam of the first node (110) can also be determined through steps S1030 and S1050, so that the transmission operation from the first node (110) can also be performed using a beam that has a reciprocal relationship with the beam selected in step S1050. If channel reciprocity is not established, a procedure including transmission of measurement signal(s) by the first node (110) and transmission of feedback signal(s) by the second node (120) may be performed first to determine the transmission beam of the first node (110).

[0177] non-terrestrial networks (NTN)

[0178] Figures 12 and 13 illustrate examples of NTN scenarios to which some examples of the present disclosure may be applied.

[0179] NTN can represent a network or network segment that uses radio frequency (RF) resources mounted on a satellite (or unmanned aerial system (UAS) platform).

[0180] Figure 12 shows an example of a typical scenario of NTN based on transparent payload, and Figure 13 shows an example of a typical scenario of NTN based on regenerative payload.

[0181] Referring to Figure 12, a satellite (or UAS platform) can establish a service link with a terminal. The satellite (or UAS platform) can be connected to a gateway via a feeder link. The satellite can be connected to a data network via the gateway. The beam footprint can refer to the area where the signal transmitted by the satellite can be received.

[0182] Referring to Figure 13, a satellite (or UAS platform) can establish a service link with a terminal. A satellite (or UAS platform) connected to a terminal can be connected to another satellite (or UAS platform) via an inter-satellite link (ISL). The other satellite (or UAS platform) can be connected to a gateway via a feeder link. Based on the regenerated payload, the satellite can be connected to a data network through another satellite and the gateway. If an ISL does not exist between the satellite and another satellite, a feeder link between the satellite and the gateway may be required.

[0183] Figures 12 and 13 are merely examples of NTN scenarios, and NTN can be implemented based on various scenarios. For example, a satellite (or UAS platform) can implement a transparent or regenerative (e.g., with onboard processing) payload. For example, a satellite (or UAS platform) can generate multiple beams across a designated service area depending on the field of view of the satellite (or UAS platform). For example, the field of view of the satellite (or UAS platform) can vary depending on the onboard antenna diagram and the minimum elevation angle.

[0184] For example, a transparent payload may include radio frequency filtering, frequency conversion, and amplification. Therefore, the waveform signal repeated by the payload may remain unchanged.

[0185] For example, a regenerative payload may include radio frequency filtering, frequency conversion and amplification, demodulation / decoding, switching and / or routing, and coding / modulation. For example, a regenerative payload may be substantially equivalent to mounting all or part of a base station function on a satellite (or UAS platform).

[0186] Integrated Sensing and Communication (ISAC)

[0187] Wireless sensing is a technology that uses radio frequencies to determine the instantaneous linear velocity, angle, distance (or range) of an object, and thus obtain 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, such as 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 communications network to a wireless communication and sensing network.

[0188] FIG. 14 illustrates examples of sensing operations to which some examples of the present disclosure may be applied.

[0189] Specifically, Fig. 14(a) shows an example of a monostatic sensing operation using a sensing receiver and a sensing transmitter located in the same location. Fig. 14(b) shows an example of a bistatic sensing operation using a sensing receiver and a sensing transmitter located in separate locations. A sensing signal transmitted from a sensing transmitter is reflected / scattered by a sensing object, and the sensing receiver can receive the signal, and extract / obtain sensing data based on the received signal. A sensing result can be generated / determined through appropriate processing of the sensing data. The sensing result can be provided to a trusted third-party entity / service outside the 3GPP system through an entity / service within the 3GPP system.

[0190] Low-power wake-up signal (LP-WUS) and low-power wake-up receiver (LP-WUR)

[0191] User devices or terminals in existing wireless communication systems consume tens of milliwatts of power even in RRC idle / inactive states, and hundreds of milliwatts in RRC connected states. To reduce power consumption and improve user experience, various methods are being discussed to extend battery life or improve energy efficiency.

[0192] Energy efficiency is even more important for devices with limited or no continuous energy sources (e.g., sensors, actuators, wearable devices, etc.). Power consumption can vary depending on the length of the wake-up interval (e.g., paging cycle). While longer extended-discontinuous reception (eDRX) cycles can be used to meet battery life requirements, this may not be suitable for low-latency applications (e.g., fire sensors and fire extinguisher actuators).

[0193] Terminals in existing wireless communication systems are required to wake up periodically, once per DRX cycle. This leads to power consumption even when there is no signal or data traffic for the terminal. If the terminal were to wake up only when triggered, such as by paging, power consumption could be significantly reduced. To achieve this, a wake-up signal can be used to trigger the main radio (MR), and a separate receiver that can monitor the wake-up signal with ultra-low power consumption can be used. The MR operates for data transmission and reception and can be turned off or set to deep sleep unless turned on.

[0194] In the present disclosure, MR refers to a transmit / receive module that operates on general wireless (e.g., NR) signals / channels, excluding signals / channels related to low-power wake-up. Additionally, a low-power-wake-up receiver (LP-WUR), which may also be referred to as LR, refers to a receiver module that operates to receive / process signals / channels related to low-power wake-up.

[0195] For LP-WUS and LP-WUR: IoT applications such as industrial wireless sensors, controllers, and actuators; wearable applications such as smartwatches, smart rings, and medical monitoring devices; and eMBB applications such as XR / smart glasses and smartphones.

[0196] For LP-WUS and LP-WUR, considering the benefits and scope of power savings and the resulting impact on system overhead and network energy, it is necessary to design an architecture for LP-WUR and define / change procedures and protocols for lower layers (e.g., L1 PHY) and upper layers (e.g., L2 MAC, L3 RRC, etc.) that support LP-WUS.

[0197] Accordingly, when sufficient relaxation is applied to MR radio resource management (RRM) measurements in RRC idle / inactive mode, it is expected that significantly reduced terminal power consumption can be achieved by triggering MR paging monitoring of the terminal using LP-WUS / WUR, compared to both with and without paging early indication (PEI) in I-DRX (idle-DRX). In addition, unlike the existing eDRX operation where paging monitoring is limited within the PTW (paging time window), it is expected that paging latency can be significantly reduced when monitoring paging after LP-WUS monitoring and MR wake-up, and thus terminal power consumption can be reduced. In addition, it is expected that reduced terminal power consumption can be achieved even in RRC connected mode when LP-WUS / WUR is used to trigger the terminal to monitor PDCCH in MR, and the MR enters a deep sleep state while LR is performing LP-WUS monitoring.

[0198] In addition, since the terminal must wake up at regular intervals to perform RRM measurements in addition to receiving paging through MR, it is expected that terminal power consumption can be reduced if some or all of the RRM measurements through MR can be offloaded to be performed through LR.

[0199] In this way, the longer the MR power off / sleep / deep sleep state is maintained, the more power consumption of the terminal can be reduced.

[0200] To make LP-WUS universally applicable to both RRC idle / inactive mode and RRC connection, OOK-based (e.g., OOK-1 and / or OOK-4) LP-WUS can be specified by superimposing OFDM sequences on OOK (on-off keying) symbols. In addition, the design of LP-WUS should ensure that the same information is conveyed regardless of the type of LP-WUR for idle / inactive operation, and that OFDM sequences can carry the information. In addition, duty-cycle based monitoring can be supported for LP-WUS.

[0201] Briefly explain the OOK-1 and OOK-4 methods.

[0202] Basically, the OOK scheme may include generating a multiple carrier-amplitude shift keying (MC-ASK) waveform. For example, an N-length LP-WUS and a typical wireless communication signal (e.g., a legacy NR signal) may be mapped to K subcarriers (e.g., SC#0 to SC#K-1). Specifically, an N-length LP-WUS signal may be mapped to SC#0 to SC#N-1, and a legacy NR signal may be mapped to SC#N to SC#K-1. The K subcarriers may be converted to a time domain signal through an inverse fast Fourier transform (IFFT), and a cyclic prefix (CP) may be appended to generate an OFDM symbol including the CP. Here, K is the size of the IFFT of CP-OFDMA (cyclic prefix-OFDMA), and N corresponds to the number of subcarriers (SCs) used in LP-WUS including a potential guard band.

[0203] In the OOK-1 scheme, information about a single bit can be signaled through a single OFDM symbol. OOK=1 can mean that all SCs are modulated, and OOK=0 can mean that all SCs have zero power (from a baseband perspective).

[0204] In the OOK-4 scheme, an M-bit OOK can be transformed in the time domain. For example, for an LP-WUS time domain signal of length N' samples for M bits, it is transformed into a frequency domain signal through DFT / LS (discrete Fourier transform / least square), and N-length OOK-1 LP-WUS subcarriers can be generated with or without signal truncation / modification (when N' is different from (greater than) N) or without (when N' is equal to N). This N-length LP-WUS signal and a general wireless communication signal (e.g., legacy NR signal) are mapped to K subcarriers (e.g., SC#0 to SC#K-1) (N' may be equal to K), and through IFFT+CP, one OFDM symbol including CP can be generated. Information for M bits can be signaled in this one OFDM symbol.

[0205] In the case of OOK-4, the Zadoff-Chu (ZC) sequence, M-sequence, and quadrature amplitude modulation (QAM) sequence before applying DFT / LS have a lot of phase variation, so a flat spectrum is expected and can provide robustness against frequency-selective fading. In addition, when DFT is applied to OOK-4 (e.g., when the value of M is 2 or greater), a frequency shift in the frequency domain or a -1 / 1 alternation in time may be applied to match the CP-OFDM generation. If the sequence(s) used for LP-WUS generation are repeated in the frequency domain, the diversity of MC-OOK and the robustness against frequency offset of MC-FSK (multiple carrier-frequency shift keying) can be improved.

[0206] In the present disclosure, a symbol modulated by OOK-1 or OOK-4 may be referred to as an OOK symbol (or OOK signal). Unless explicitly distinguished in the present disclosure, an OOK symbol / signal may mean a symbol / signal modulated by OOK-1 and / or OOK-4.

[0207] The synchronization signal (SS) used in LP-WUR may be referred to as LP-SS. For example, LP-SS may be an aperiodic signal transmitted as part of LP-WUS. In this case, LP-SS may or may not be transmitted additionally separately from LP-WUS. Alternatively, LP-SS may be a periodic signal transmitted separately from LP-WUS. Alternatively, LP-SS may include both an aperiodic signal transmitted as part of LP-WUS and a periodic signal transmitted separately from LP-WUS.

[0208] With respect to RRM measurements performed in LP-WUR, measurement metrics may include signal quality, signal power, LP-WUS / SS detection rate, etc. For RRM serving cell measurements performed by LP-WUR based on reference signals, LP-RSSI (received signal strength indicator) or energy detection, LP-RSRP, LP-SINR, LP-RSRQ, etc. may be defined. As these reference signals, SSB, LP-WUS-waveform sequence, LP-SS, etc. may be used.

[0209] Periodic LP-SS may also be used for RRM measurements by LP-WUR, coarse time synchronization of LP-WUR, coarse frequency synchronization of LP-WUR, etc.

[0210] If LP-WUR can receive existing primary synchronization signal (PSS) / secondary synchronization signal (SSS), which may be assisted by PBCH-DMRS (demodulation reference signal) / TRS (tracking reference signal), it may also use it for RRM measurement / time synchronization / frequency synchronization.

[0211] The coverage (e.g., reach / range) of a periodic LP-SS may be better than or equal to that of an LP-WUS.

[0212] For precise time / frequency synchronization, additional signals (e.g., a preamble) may be used before or as part of the LP-WUS.

[0213] As for the LP-SS period, 320ms can be supported. For example, periods of 80ms, 160ms, 640ms, 1280ms, 2560ms, 5120ms, and 10240ms may also be supported for LP-SS.

[0214] Additional synchronization signals for LP-SS may or may not be present. If present, additional synchronization signals may be configured for the terminal by signaling from the network, and / or may be predefined as present (without separate signaling) when certain conditions are met. For example, in OOK modulation for LP-WUS, additional synchronization signals may or may not be present depending on the value of M.

[0215] FIG. 15 and FIG. 16 are diagrams for explaining examples of the OOK method for an LP signal according to the present disclosure.

[0216] The LP signal may include LP-SS and / or LP-WUS. That is, the examples of FIGS. 15 and 16 may be applied to both LP-SS and LP-WUS.

[0217] Referring to FIG. 15, for example, among the total K subcarriers (SC#0, ..., SC#K-1), an LP signal of length N can be mapped to SC#0, SC#1, ..., SC#N-1, and a legacy signal of length KN can be mapped to SC#N, SC#N+1, ..., SC#K-1. An OFDM symbol (including a CP) can be generated through an IFFT transform and CP addition for the K subcarriers. In an OOK-1 scheme such as the example of FIG. 15, information for a single bit can be signaled through one OFDM symbol. OOK=1 can mean that all SCs are modulated, and OOK=0 can mean that all SCs have zero power (from a baseband perspective).

[0218] Referring to Fig. 16, for example, when M = 4 bits, an LP signal of length N' samples corresponding to a 4-bit sequence 1001 can be generated. The signal of length N' is converted into a frequency domain signal through DFT / LS, and, if necessary, truncation / modification can be applied so that N subcarriers of OOK-1 can be generated for the LP signal. This LP signal of length N and a legacy signal of length KN can be mapped to K subcarriers, and through IFFT+CP, one OFDM symbol including CP can be generated. Information for M bits can be signaled through this one OFDM symbol.

[0219] SSB (synchronization signal / PBCH (physical broadcast channel) block)

[0220] FIG. 17 is a diagram illustrating an example of an SSB time resource to which the present disclosure can be applied.

[0221] An SSB burst defined in an NR system may include SSB time resources. Fig. 17(a) shows examples of SSB time resource locations according to subcarrier spacing (SCS) in frequency range 1 (FR1), which corresponds to a frequency band of 6 GHz or less or from 410 MHz to 7125 MHz. Fig. 17(b) shows examples of SSB time resource locations according to SCS in frequency range 2 (FR2) (or mmWave band), which corresponds to a frequency band of 6 GHz or more or from 24.25 GHz to 52.6 GHz.

[0222] Case A - For 15 kHz SCS in FR1, the first symbol of the candidate SSBs can correspond to the index of {2,8} + 14*n. For operation without shared spectrum channel access, n=0, 1 for carrier frequencies below 3 GHz, and n=0, 1, 2, 3 for carrier frequencies within FR1 above 3 GHz. For operation supporting shared spectrum channel access, n=0, 1, 2, 3, 4.

[0223] Case B - For the first case of 30 kHz SCS in FR1, the first symbol of the candidate SSBs can correspond to the index of {4,8,16,20} + 28*n. For carrier frequencies below 3 GHz, n=0, and for carrier frequencies within FR1 above 3 GHz, n=0, 1.

[0224] Case C - In the second case of 30 kHz SCS in FR1, the first symbol of the candidate SSBs may correspond to the index of {2,8} + 14*n. For operation without shared spectrum channel access, for paired spectrum operation, n=0, 1 for carrier frequencies below 3 GHz, and n=0, 1, 2, 3 for carrier frequencies within FR1 above 3 GHz within FR1. For unpaired spectrum operation, n=0, 1 for carrier frequencies below 1.88 GHz, and n=0, 1, 2, 3 for carrier frequencies within FR1 above 1.88 GHz within FR1. For operation supporting shared spectrum channel access, n=0, 1, 2, 3, 4, 5, 6, 7, 8, 9.

[0225] Case D - For 120 kHz SCS in FR2, the first symbol of the candidate SSBs can correspond to the index {4,8,16,20} + 28*n. For carrier frequencies within FR2, n = 0, 1, 2, 3, 5, 6, 7, 8, 10, 11, 12, 13, 15, 16, 17, 18.

[0226] Case E - For 240kHz SCS in FR2, the first symbol of the candidate SSBs can correspond to the index {8,12,16,20,32,36,40,44} + 56*n. For carrier frequencies within FR2-1, n=0, 1, 2, 3, 5, 6, 7, 8.

[0227] Case F - For 480 kHz SCS in FR2, the first symbol of the candidate SSBs can correspond to the index of {2, 9} + 14*n. For carrier frequencies within FR2-2, n = 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31.

[0228] Case G - For 960 kHz SCS in FR2, the first symbol of the candidate SSBs can correspond to the index of {2, 9} + 14*n. For carrier frequencies within FR2-2, n = 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31.

[0229] LP-SS group transmission / reception

[0230] This disclosure describes transmission / reception for LP-SS groups.

[0231] While the following description describes a specific wireless communication system (e.g., an NR system) as an example of a wireless communication system to which the examples of the present disclosure apply, the scope of application of the present disclosure is not limited to a specific wireless communication system. The examples of the present disclosure can be applied to any wireless communication system within the scope that maintains the characteristics of the invention.

[0232] In order to reduce the number of times a terminal wakes up the MR, it is necessary to receive a synchronization signal (e.g., LP-SS) in advance or simultaneously with the wake-up signal (e.g., LP-WUS). This disclosure describes a method for generating a sequence for LP-SS and a related setting method.

[0233] In conventional wireless communication systems, a base station can generate and transmit OFDM signals to send control / data signals to a terminal. In this case, the terminal requires relatively accurate synchronization to receive the OFDM signal, and for this purpose, a coherent detection and demodulation-based receiver can be utilized. Such a receiver may require power-consuming RF modules such as a bandpass filter (BPF), fast Fourier transform (FFT), and local oscillator, as well as a baseband module. In LP-WUR that receives LP-WUS, a non-coherent detection and demodulation-based receiver can be utilized instead of the power-consuming modules mentioned above to receive signals at low power. As an LP-WUS signal for such a low-power receiver, an OOK-1 / OOK-4 signal (with or without an overlaid OFDM sequence) can be used. These OOK-1 / OOK-4 signals are used as MC-OOK signals to make full use of the OFDM transmitter of the base station, and the signal generation method and maximum number of bits that can be transmitted may vary depending on the option.

[0234] Additionally, receiver capabilities may vary depending on the WUR type. For example, some WURs may have the capability to detect OFDM sequences overlaid on OOK signals, while others may not. Supporting OFDM sequences overlaid on OOK signals may increase coverage or allow additional bits to be transmitted.

[0235] In this disclosure, the transmission scheme of LP-SS is classified as follows:

[0236] Transmission method 1: LP-SS is transmitted as part of LP-WUS and corresponds to a signal transmitted aperiodically;

[0237] Transmission method 2: LP-SS is transmitted separately from LP-WUS and corresponds to a signal that is transmitted periodically;

[0238] Transmission method 3: By applying both transmission methods 1 and 2, LP-SS is transmitted aperiodically as part of LP-WUS, and also periodically separately from LP-WUS.

[0239] The aperiodic LP-SS described above may be transmitted as a part of the LP-WUS or in the form of a preamble. The aperiodic LP-SS may be transmitted together with (or included in) the LP-WUS when there is a transmission of the LP-WUS, but the aperiodic LP-SS may not be transmitted when there is no transmission of the LP-WUS. The LP-WUS may be transmitted to the terminal when an event that requires waking up the MR of the terminal occurs. That is, the LP-WUS is transmitted based on an event, and the aperiodic LP-SS may be transmitted together with the LP-WUS when the LP-WUS is transmitted based on such an event.

[0240] The waveform applied to LP-SS in the present disclosure may include the following options.

[0241] Option 1: OOK-1

[0242] Option 2: OOK-4 with M=1, 2, 4, or 8

[0243] The present disclosure describes the transmission / reception of a group of LP-SS, which is a synchronization signal, in a low-power communication system supporting LP-WUS. A group of LP-SS may include one or more LP-SS elements. Each LP-SS element may be identified by an SS index / ID and may correspond to a distinct beam direction. For example, an LP-SS group may be expressed as an LP-SS burst, and the terms LP-SS group and LP-SS burst in the present disclosure may be interchangeable. An LP-SS burst / group may correspond to a group of LP-SS indices / IDs / transmissions corresponding to multiple beams. That is, different LP-SS transmissions (i.e., transmissions corresponding to different LP-SS indices / IDs) within one LP-SS burst / group may correspond to different beam directions. Beams corresponding to LP-SS indices included in one LP-SS burst / group may be transmitted sequentially (or in a sweeping manner). The correspondence of a reference signal to an LP-SS index can be expressed as QCL (quasi-co-located) between the reference signal and the LP-SS. Different LP-SS indices can be QCLed with different reference signals.

[0244] In the present disclosure, transmission / reception of an LP-SS group can be performed by a mutual relationship (e.g., offset, etc.) with respect to a reference time resource and / or a reference frequency resource (hereinafter, reference time-frequency resource, or reference resource). For example, in a low-power communication system supporting LP-WUS, a reference resource for an LP-SS, which is a synchronization signal, can be an SSB, which is a synchronization signal used in a cellular communication system (e.g., an NR system). For example, the reference resource for an LP-SS group can be an SSB group / burst.

[0245] FIG. 18 is a drawing for explaining an example of a method performed by a terminal according to the present disclosure.

[0246] In step S1810, the terminal can receive one or more first SSs from the network within the first time interval.

[0247] In step S1820, the terminal may receive one or more second SSs from the network within a second time interval based on the resource locations of the first time interval and / or one or more first SSs.

[0248] In some examples, one or more first SSs may be associated one-to-one with one or more second SSs. For example, a first time interval may include a plurality of first SSs corresponding to different indices or beams, and a second time interval may include a plurality of second SSs corresponding to different indices or beams. These plurality of first SSs and the plurality of second SSs may be associated (based on the same index or beam).

[0249] In some examples, the first time interval may correspond to an SSB burst and the second time interval may correspond to an LP-SS group.

[0250] In some examples, before the first time interval or before the second time interval, information including value(s) of offset parameter(s) for resource locations of the second time interval and / or resource locations of one or more second SSs may be set / instructed to the terminal from the network.

[0251] For example, the information about the offset parameter(s) may include a first offset parameter between the starting point of the first time interval and the starting point of the second time interval. Additionally, the information may include a second offset parameter between the starting point of the second time interval and the starting point of the first second SS.

[0252] For example, information about the offset parameter(s) may include a first offset parameter between the start point of a first time interval and the start point of a second time interval. Additionally, the information may include a second offset parameter between the end point of a first second SS and the start point of a second second SS.

[0253] For example, the information about the offset parameter(s) may include a frequency offset parameter between one or more first SSs and one or more second SSs. Additionally, the information may include a first time offset parameter between a starting point of a first time interval and a starting point of a second time interval. Furthermore, the information may include a second time offset parameter between a starting point of a second time interval and a starting point of a first second SS.

[0254] For example, the information about the offset parameter(s) may include a first offset parameter between the start point of the first time interval and the start point of the second time interval. Additionally, the information may include a second offset parameter between the start point of the second time interval and the start point of the first second SS. Furthermore, the information may include a third offset parameter between the end point of the first second SS and the start point of the second second SS.

[0255] For example, the information about the offset parameter(s) may include a first offset parameter between a start point of a first time interval and a start point of a second time interval. Additionally, the information may include a second offset parameter between a start point of the second time interval and a start point of a first second SS. Furthermore, the information may include one or more third offset parameters for an interval between consecutive second SSs (i.e., an interval between an end point of a preceding second SS and a start point of a subsequent second SS).

[0256] For example, the information about the offset parameter(s) may include a first offset parameter between a starting point of a first time interval and a starting point of a second time interval. Additionally, the information may include a second offset parameter between a starting point of the second time interval and a starting point of a first second SS. Furthermore, the information may include one or more third offset parameters between a starting point of the first second SS and a starting point of each of the remaining one or more second SSs.

[0257] For example, information about the offset parameter(s) may include an offset parameter between the starting point of a first first SS among one or more first SSs and the starting point of each of the k (k=0, 1, 2, ...)-th second SSs.

[0258] For example, information about the offset parameter(s) may include each offset parameter between the starting point of the k (k=0, 1, 2, ...)-th first SS and the starting point of the k-th second SS.

[0259] In the example of Fig. 18, the first SS may be received by the main radio (MR) of the terminal. The second SS may be received by the low-power wake-up receiver (LP-WUR) of the terminal. For example, the first SS may be included in the SSB, and the second SS may be a low-power SS (LP-SS).

[0260] The method described in the example of FIG. 18 may be performed by the wireless device (200) of FIG. 3 corresponding to the first node (110) of FIG. 2 described above. For example, one or more processors (202) of the wireless device (200) of FIG. 3 may be configured to receive one or more first SSs from the network via one or more transceivers (206) within a first time interval, and to receive one or more second SSs from the network via one or more transceivers (206) within a second time interval. For example, the one or more transceivers (206) may include MR and LP-WUR. Furthermore, one or more memories (204) of the wireless device (200) may store instructions for performing the method described in the example of FIG. 18 or the examples described below when executed by one or more processors (202).

[0261] FIG. 19 is a drawing illustrating an example of a method performed by a base station according to the present disclosure.

[0262] In step S1910, the base station may transmit one or more first SSs to the terminal within the first time interval.

[0263] In step S1920, the base station may transmit one or more second SSs to the terminal within the second time interval based on the resource locations of the first time interval and / or the resource locations of one or more first SSs.

[0264] The specific characteristics of the first time interval, the second time interval, the first SS, the second SS, and the offset of the relative time / frequency resource positions between them are the same as the description referring to the example of Fig. 18, so the redundant description is omitted.

[0265] The method described in the example of FIG. 19 may be performed by the wireless device (200) of FIG. 3 corresponding to the second node (120) of FIG. 2 described above. For example, one or more processors (202) of the wireless device (200) of FIG. 3 may be configured to transmit one or more first SSs to a terminal via one or more transceivers (206) within a first time interval, and to transmit one or more second SSs to the terminal via one or more transceivers (206) within a second time interval. The terminal to which the wireless device (200) transmits the second SSs may be a terminal that has notified the base station that it has the LP-WUR capability or a terminal that the base station knows in advance. Furthermore, one or more memories (204) of the wireless device (200) may store commands for performing the method described in the example of FIG. 19 or the examples described below when executed by one or more processors (202).

[0266] FIG. 20 is a diagram illustrating an example of signaling between a base station and a terminal according to the present disclosure.

[0267] In step S2010, the base station may determine values ​​of offset parameter(s) related to resource locations of the LP-SS group and / or resource locations of the LP-SS(s). For example, the offset parameter may include information about time / frequency resources of the LP-SS burst relative to time / frequency resources of the SSB burst. For example, the offset parameter may include predetermined time offset information with reference to the time resource location of the SSB, and / or predetermined frequency offset information with reference to the frequency resource location of the SSB. Additionally or alternatively, the offset parameter may include offset parameters according to various examples of the present disclosure described below, such as information about an offset / interval between a first LP-SS and a second LP-SS within the LP-SS burst.

[0268] In step S2020, information for setting / indicating these offset parameter(s) is provided to the terminal (e.g., broadcast to multiple terminals), and the terminal can receive an LP-SS based on this in step S2030. In step S2040, the terminal can perform synchronization and / or RRM measurement based on the received LP-SS.

[0269] In the present disclosure, setting or pre-setting specific information for a terminal may mean that the specific information is provided by upper layer (e.g., L3 RRC) signaling from the network. In the present disclosure, indicating specific information for a terminal may mean that the specific information is provided by lower layer (e.g., L2 MAC or L1 PDCCH / DCI) signaling from the network. For example, if information A including candidate values ​​a1, a2, a3, ... is set for a terminal (via upper layer signaling), and a1 among them is indicated to the terminal (via lower layer signaling), the terminal can operate based on the value a1. In the present disclosure, pre-defining specific information may mean that the network and the terminal each assume or know in advance that the specific information exists / is applied without signaling between the network and the terminal.

[0270] Below, various examples of the present disclosure for transmission / reception of LP-SS groups based on reference time / frequency resources are described.

[0271] Example 1

[0272] The present embodiment relates to transmission / reception of an LP-SS group including multi-beams using an SSB burst as a reference resource.

[0273] As mentioned above, beamforming technology can be applied to overcome issues such as coverage limitations caused by path loss in high-frequency communication systems. For example, during the initial connection process in a conventional cellular communication system, a base station can transmit multiple beams operated by the base station via SSB bursts, thereby conveying beam direction information to the terminal and allowing the terminal to select an appropriate beam for its location.

[0274] Even in low-power communication systems that support LP-WUS, multi-beam-based LP-SS can be transmitted similarly to the multi-beam operation applied in existing cellular communication systems. In this embodiment, various examples for multi-beam operation in an LP-WUS communication system are described based on the interrelationship between SSB bursts used for multi-beam operation in an NR communication system and LP-SS groups, which play a role similar to that of SSB in an LP-WUS communication system.

[0275] For example, a relationship between an SSB burst and an LP-SS group in the time domain and / or frequency domain can be defined / established. More specifically, a time resource and / or a frequency resource of an LP-SS group (and each of one or more LP-SS indices / beams included in the LP-SS group) can be defined / established with reference to a time resource and / or a frequency resource of an SSB burst (and each of one or more SSB indices / beams included in the SSB burst).

[0276] In the present disclosure, it can be assumed that the number of LP-SS indices / beams within an LP-SS group corresponds to the number of SSB indices / beams within an SSB burst. Furthermore, a one-to-one mapping / association between LP-SS indices / beams and SSB indices / beams can be assumed.

[0277] Example 1-1

[0278] Resources of each LP-SS index within an LP-SS group can be set / indicated through slot / symbol offsets, with each SSB index within an SSB burst as a reference.

[0279] For each SSB within an SSB burst, a slot offset and / or a symbol offset may be given to an LP-SS transmitting the same beam, and accordingly, an LP-SS group may be formed. The time resource of an LP-SS may be set / indicated through a combination of a slot offset (offset_slot) and a symbol offset (offset_sym).

[0280] For example, assuming that a base station operates four transmission beams in total, one SSB burst can contain a total of four SSB indices, SSB#0, SSB#1, SSB#2, and SSB#3. An LP-SS group can also contain a total of four LP-SS indices, LP-SS#0, LP-SS#1, LP-SS#2, and LP-SS#3, just like an SSB burst. If the values ​​of the SSB index and the LP-SS index are the same, they can be assumed to be the same transmission beam (or QCLed with the same reference signal). Assuming an SSB burst and an LP-SS group in this way, the time resource of the LP-SS corresponding to the SSB can be set / indicated through a combination of two offsets, offset_slot and offset_sym, respectively.

[0281] Specifically, the offset_slot value may correspond to the difference value from the slot index of the SSB to the slot index of the LP-SS corresponding to the SSB. For example, if SSB#0 is transmitted in slot k, the corresponding LP-SS#0 may be transmitted in slot {k + offset_slot}. The starting symbol index of the LP-SS within the LP-SS slot may be set / indicated via offset_sym. For example, if the value of offset_sym is set / indicated to 2, the terminal may determine / apply that the LP-SS starts from the symbol index {2} within the slot.

[0282] FIG. 21 is a diagram illustrating an example of a slot offset and a start symbol offset between an SSB burst and an LP-SS group according to the present disclosure.

[0283] In the example of Fig. 21, offset_slot corresponds to the difference between the start timing of an SSB burst and the start timing of an LP-SS group, and offset_sym corresponds to the difference between the start timing of an LP-SS group and the start timing of the first LP-SS index / beam. Here, the spacing between LP-SSs within an LP-SS group (e.g., the difference between the last symbol of beam #0 LP-SS and the first symbol of beam #1 LP-SS, the difference between the first symbol of beam #0 LP-SS and the first symbol of beam #1 LP-SS) may be the same as or different from the spacing between SSBs within an SSB burst.

[0284] The spacing between SSBs within an SSB burst may vary depending on the case or SCS described with reference to FIG. 17, as described above. The spacing between LP-SSs within an LP-SS group may also be set / indicated to be the same as the spacing between SSBs within an SSB burst. In cases where the SCS used in an SSB is different from the SCS used in an LP-SS, the spacing between LP-SSs may be set / indicated with reference to a specific SCS and case of the SSB.

[0285] For example, the same symbol spacing as the SSB case corresponding to the SCS used by the LP-SS can be utilized, or the absolute time spacing can be made the same by scaling according to the SCS used by the LP-SS with SSB Case A (SCS=15kHz) as a reference. For example, when setting / indicating the spacing between LP-SSs within an LP-SS group with SSB Case A as a reference, if the SCS used by the LP-SS is 30kHz, the spacing between SSBs in SSB Case A can be scaled up by a factor of 2 to set / indicate the spacing between LP-SSs.

[0286] This scaling value may be applied according to the SCS (ratio), or may be set / indicated via a higher layer parameter (e.g., RRC signaling or SIBx (e.g., x=1)). Alternatively, the spacing between LP-SSs within an LP-SS group may vary depending on the M value, which is a parameter related to the waveform of the LP-SS (i.e., the number of OOK symbols mapped to one OFDM symbol). For example, the spacing between LP-SSs may be set / indicated via scaling according to the M value (ratio). For example, the spacing between LP-SSs within an LP-SS group may be set / indicated to be the same as the spacing between SSBs within an SSB burst (e.g., 6 OFDM symbols for Case A in the example of FIG. 17 for SS / PBCH time domain location, or 4 OFDM symbols for Case B).

[0287] Additionally or alternatively, since LP-SS may have a different temporal structure than SSB, LP-SS groups may also be structured differently from SSB bursts. Accordingly, the spacing between LP-SSs within an LP-SS group may also be predefined independently of the spacing between SSBs within an SSB burst.

[0288] For example, the spacing between adjacent LP-SSs within an LP-SS group may be pre-defined in time units (e.g., subframes / slots / symbols) corresponding to a specific SCS (e.g., an SCS set / indicated for an LP-SS / LP-WUS, or an SCS set / indicated for an MR (main radio) active DL BWP), so that an LP-SS group may be formed. For example, if the spacing between LP-SSs is pre-defined in slot units (e.g., A slots) corresponding to a specific SCS, the spacing between LP-SS#0 (beam#0) and LP-SS#1 (beam#1) in the example of FIG. 21 may be set / indicated as A slots, and the spacing between subsequent LP-SSs may also be set / indicated as the same spacing, so that an LP-SS group may be formed.

[0289] The spacing between LP-SSs within a pre-defined LP-SS group may vary depending on the SCS, similar to the spacing between SSBs within an NR SSB burst. The spacing between pre-defined LP-SSs, regardless of the spacing between SSBs within an SSB burst, may also be varied depending on a specific SCS (e.g., an SCS configured / indicated for an LP-SS / LP-WUS, or an SCS configured / indicated for an MR active DL BWP).

[0290] Although the example in Fig. 21 describes slot / symbol offsets by utilizing parameters such as offset_slot and offset_sym, the offset related to the time resource position of the LP-SS is not limited to slot / symbol units, and offset information may be set / indicated in the form of a combination of SFN / slot / symbol. For example, when the time offset is expressed in the form of (SFN, slot, symbol), the resources of the first LP-SS may be set / indicated at a time position that is 1 subframe, 2 slots, and 4 symbols away from the SSB burst start point (or the first SSB start point), such as (1,2,4).

[0291] Alternatively, assuming that the frame index in which the SSB is transmitted is A, the frame index (A + offset_SFN) that is spaced apart from the SSB burst start point by a subframe set / instructed or pre-defined by the base station (the time offset in units of SFN, offset_SFN) may correspond to the frame in which the LP-SS is transmitted. For example, offset_SFN may be 1. In this case, the slot offset (e.g., 2 slots) and / or the symbol offset (e.g., 4 symbols) may correspond to the time offset from the start point of the frame in which the LP-SS is transmitted.

[0292] As another example, the frame index at which LP-SS is transmitted can be set / indicated through information that directly indicates the index, rather than being derived based on the offset. For example, if the frame index is set to 'even', LP-SS may be transmitted only in frames where modulo(frame index, 2) = 0, and LP-SS may not be transmitted in frames where the modulo 2 operation results in 1. Alternatively, if the frame index is set to 'odd', LP-SS may be transmitted only in frames where modulo(frame index, 2) = 1, and LP-SS may not be transmitted in frames where the modulo 2 operation results in 0. In this way, if a frame index in which LP-SS transmission can be performed is set / indicated, an additional resource location of LP-SS can be set / indicated through an additional offset of slots / symbols from the start point of the frame in which transmission can be performed as described above.

[0293] Although the above example describes a method of distinguishing odd / even frames by applying a modulo 2 operation in a way that sets / indicates the frame index, an LP-SS transmittable frame may also be indicated by a modulo K operation (e.g., as a frame with modulo(frame index, K) = 0).

[0294] According to the examples described above, time offset information (based on SSB time position) for LP-SS can be set / indicated as a combination of one or more of SFN, slot, or symbol units.

[0295] Below are examples where offset_slot and offset_sym are set / indicated.

[0296] Example 1-1-1

[0297] Time offset information for LP-SS can be set / instructed to the terminal through signaling of upper layer parameters.

[0298] For example, two offsets, offset_slot and offset_sym, can be set / indicated via higher layer parameters (e.g., RRC signaling or SIBx (e.g., x=1)). In this case, various combinations of offsets can be flexibly set / indicated by the base station.

[0299] Example 1-1-2

[0300] Time offset information for LP-SS can be set / indicated to the terminal through signaling of an index of a pre-defined table.

[0301] For example, a table may contain multiple combinations of time offsets, each of which may be distinguished by an index. When a table index is set / indicated via a higher layer parameter (e.g., RRC signaling or SIBx (e.g., x=1)), a combination of offsets corresponding to that index may be specified in a pre-defined table.

[0302] An example of such a table is as follows. The number of indices in the table below and the respective values ​​of offset_slot and offset_sym corresponding to each index are exemplary, and different numbers and / or different values ​​may be applied. In addition, the example in the table below assumes that the slot / symbol indices are defined with SCS=15kHz as a reference. Alternatively, distinct tables may be defined for different SCSs. Alternatively, a scaling value or multiplier may be set / indicated to derive offset values ​​for other SCSs based on the offset values ​​in the table defined for SCS=15kHz.

[0303] Index offset_slot (slot) offset_sym (symbol) 112214322424542644782884

[0304] Example 1-2

[0305] LP-SS resources can be configured / indicated through time offsets from SSB bursts and time offsets between LP-SSs within an LP-SS group.

[0306] For example, offset_SSB, which is a time offset between an SSB burst and an LP-SS group, and offset_LP-SS, which is a time offset between LP-SSs within an LP-SS group, may be set / indicated. Here, offset_SSB may correspond to a time offset between a start slot / symbol of an SSB burst and a start slot / symbol of an LP-SS.

[0307] In Example 1-2, similarly to Examples 1-1-1 and 1-1-2, offset values ​​may be set / indicated to the terminal, or an index corresponding to a combination of predefined offset values ​​may be set / indicated to the terminal. The table below corresponds to exemplary combinations of offset_SSB and offset_LP-SS. For example, offset values ​​such as the table below, which reference SCS=15kHz, may be predefined.

[0308] Index offset_SSB (ms) offset_LP-SS (symbol) 1202220434024404580268047160281604

[0309] FIG. 22 is a diagram showing an example of an SSB offset between an SSB burst and an LP-SS group and a symbol offset between LP-SSs according to the present disclosure.

[0310] For example, the first LP-SS start symbol index within an LP-SS group may be the same as the first SSB start symbol index within an SSB burst. The first LP-SS start symbol index within an LP-SS group may be the same as the first SSB start symbol index within an SSB burst, and may be different from the first SSB start symbol index within an SSB burst considering the duration of the LP-SS. For example, when the first SSB start symbol index within an SSB burst is 4, the first LP-SS start symbol index within an LP-SS group may be pre-defined as 2.

[0311] For example, the unit of offset_SSB may be milliseconds (ms), and the unit of offset_LP-SS may be symbols. Alternatively, the unit of offset_SSB may be slots. Alternatively, the unit of offset_LP-SS may be defined as an absolute time length value (e.g., microseconds (us), or ms) or slot units. In addition, the information of the offset is not limited to slot / symbol units, and SFN can also be used. For example, offset_SSB may be expressed in SFN or slot units (e.g., 1 subframe or 10 slots). For example, offset_LP-SS is not limited to symbol units, and may be defined as a slot or an absolute time length value (e.g., us, ms, etc.).

[0312] Example 1-3

[0313] LP-SS resources can be set / indicated through frequency offsets for LP-SSs that are frequency division multiplexed (FDM) with SSB bursts, and time offsets for remaining LP-SSs that are time division multiplexed (TDM) with SSB bursts.

[0314] For example, assuming that the duration of each SSB within an SSB burst is 4 symbols, an LP-SS with a duration of 4 symbols corresponding to the SSB duration can be transmitted in an FDM manner on the same time resource and a different frequency resource as the SSB. In this case, the remaining LP-SS can be transmitted in a TDM manner with the SSB (e.g., on the same frequency resource and a different time resource).

[0315] For this, three offset parameters may be required. For example, a frequency offset for FDM between SSB and LP-SS, and two time offsets for TDM between SSB and the remaining LP-SS may be set / indicated.

[0316] FIG. 23 is a diagram showing an example of a frequency offset and a time offset between an SSB burst and an LP-SS group according to the present disclosure.

[0317] The frequency offset (or frequency resource location) related to FDM of SSB and LP-SS can be set / indicated in units of resource blocks (RBs). For example, the frequency offset can be defined as a value in units of RBs from the lowest or highest physical resource block (PRB) of SSB. Similar to Embodiments 1-1-1 and 1-1-2, the value of offset_PRB, which is a frequency offset, may be set / indicated to the UE through higher layer signaling (e.g., RRC signaling or SIBx (e.g., x=1)), or an index corresponding to a predefined offset value may be set / indicated to the UE.

[0318] As a time offset, offset_slot and offset_sym as in Example 1-1 may be set / indicated, or (although not shown) offset_SSB and offset_LP-SS as in Example 1-2 may be set / indicated. Alternatively, offset_SSB and offset_LP-SS may be set / indicated, or offset_slot and offset_LP-SS may be set / indicated.

[0319] When defining time offset-related parameters as in Example 1-1, the interval between LP-SSs within an LP-SS group may be the same as the interval between SSBs within an SSB burst. When defining time offset-related parameters as in Example 1-2, the start symbol index of the first LP-SS within an LP-SS group may be the same as the start symbol index of the first SSB within an SSB burst.

[0320] Similar to Embodiments 1-1-1 and 1-1-2, frequency offset and / or time offset values ​​may be set / indicated to the terminal, or an index corresponding to a predefined combination of frequency offset and / or time offset values ​​may be set / indicated to the terminal.

[0321] An example of a predefined table for frequency offsets and two time offsets is provided below. The number of parameters and their values ​​in the table are exemplary; other numbers and values ​​may apply. For example, the frequency offset may be defined in resource element (RE) units rather than PRB units.

[0322] Index offset_PRB (RB) offset_slot (slot) or offset_SSB (ms) offset_sym (symbol) or offset_LP-SS (symbol) 11220221220431240241240452480262480472416028241604

[0323] Additionally, in low-power communication systems using LP-WUS, an additional parameter, k_SSB, can be applied to align PRBs with the common resource block (CRB) for coexistence with NR communication systems. For example, the k_SSB value can be directly set / indicated. For frequency offsets in RB units, since the size of an RB unit can vary depending on the SCS, the absolute resource location in the frequency domain can vary. Therefore, scaling can be applied with a specific SCS (e.g., SCS=15kHz) as a reference.

[0324] Example 1-4

[0325] LP-SS resources can be set / indicated through time offset from an SSB burst, time offset between LP-SSs within an LP-SS group, and start symbol offset.

[0326] This embodiment may correspond to the union of the time offset parameters offset_slot, offset_sym, and offset_LP-SS described in Embodiments 1-1 and 1-2. Compared to Embodiments 1-1 and 1-2, this embodiment allows the base station to flexibly set / instruct all settings to the terminal.

[0327] The three parameters may be set / instructed to the terminal for each offset value, similar to Embodiments 1-1-1 and 1-1-2, or an index corresponding to a predefined combination of offset values ​​may be set / instructed to the terminal.

[0328] FIG. 24 is a diagram illustrating an example of a slot offset, a start symbol offset, and a symbol offset between LP-SS groups and an SSB burst according to the present disclosure.

[0329] The table below is an example of a predefined table for three time offsets. The table indices can be set / indicated to the UE via higher layer signaling (e.g., RRC signaling or SIBx (e.g., x=1)). The number of indices and the values ​​of the parameters are exemplary, and other numbers and other parameter values ​​may be applied.

[0330] Index offset_slot (slot) offset_sym (symbol) offset_LP-SS (symbol) 110 221 243 2024 2245 4026 4247 8028 824

[0331] Example 1-5

[0332] LP-SS resources can be configured / indicated via time offset from the SSB burst and time offset(s) for each LP-SS within the LP-SS group.

[0333] This embodiment is similar to embodiment 1-4, but compared to embodiment 1-4, the base station can set / indicate the resources of the LP-SS group relatively more flexibly. For example, a time offset for each LP-SS in the LP-SS group can be set / indicated, such as offset_slot, which is a time offset between an SSB burst and an LP-SS group, offset_0, which is a time offset for LP-SS#0, offset_1, which is a time offset between LP-SS#0 and LP-SS#1, and offset_2, which is a time offset between LP-SS#1 and LP-SS#2.

[0334] These time offset parameters may be set / indicated to the terminal via higher layer signaling (e.g., RRC signaling, SIB(1)), similar to Embodiments 1-1-1 and 1-1-2, or an index corresponding to a predefined combination of offset values ​​may be set / indicated to the terminal via higher layer signaling (e.g., RRC signaling, SIB(1)).

[0335] FIG. 25 is a diagram showing an example of slot offsets between SSB bursts and LP-SS groups according to the present disclosure, and time offsets for each LP-SS.

[0336] In the examples of FIG. 25(a) and FIG. 25(b), the slot offset between the SSB burst and the LP-SS group can be applied equally.

[0337] In Fig. 25(a), for the time offsets for each LP-SS, the time offset (offset_0) for LP-SS#0 is defined identically to the start symbol offset (offset_sym) described above, the time offset (offset_1) for LP-SS#1 is defined as the interval between the last symbol of LP-SS#0 and the start symbol of LP-SS#1, and the time offset (offset_2) for LP-SS#2 is defined as the interval between the last symbol of LP-SS#1 and the start symbol of LP-SS#2.

[0338] In FIG. 25(b), for the time offsets for each LP-SS, the time offset (offset_0) for LP-SS#0 is defined identically to the start symbol offset (offset_sym) described above, the time offset (offset_1) for LP-SS#1 is defined as the interval between the start symbol of LP-SS#0 and the start symbol of LP-SS#1, and the time offset (offset_2) for LP-SS#2 is defined as the interval between the start symbol of LP-SS#0 and the start symbol of LP-SS#2.

[0339] The unit of this time offset can be SFN / slot / symbol.

[0340] More specifically, a time offset to the last LP-SS (the last LP-SS among the LP-SS groups) can be defined, such as offset_slot, which is a time offset from the start of a slot in which a first SSB of an SSB burst is transmitted to the slot in which a first LP-SS of the LP-SS group is transmitted, offset_0, which is a time offset between the LP-SS group and LP-SS#0, offset_1, which is a time offset from the start of LP-SS#0 (or an LP-SS associated with beam#0) (the start symbol index of the first LP-SS in the LP-SS group) to the start of LP-SS#1 (the start symbol index of the second LP-SS in the LP-SS group), and offset_2, which is a time offset from the start of LP-SS#0 to the start of LP-SS#2. Accordingly, time resources for each LP-SS in the LP-SS group can be set / indicated.

[0341] The aforementioned offset information may be pre-defined in time units (e.g., A slots / symbols) corresponding to a specific SCS, or may be set / indicated from the base station via higher layer signaling (e.g., RRC signaling, SIBx (e.g., x=1)). For example, in the case of offset_0, the value can be defined as 0 (i.e., (the starting point of the LP-SS group and the starting point of LP-SS#0 are defined to be the same). Here, the pre-defined method can also be defined according to the number of OFDM symbols occupied by the LP-SS. For example, assuming that the number of OFDM symbols occupied by the LP-SS is A, offset_i, which is the time offset from the starting point of LP-SS#0 to the starting symbol index of the (i+1)th LP-SS in the LP-SS group, can be expressed as the formula offset_i = i*A + D_i. Here, D_i corresponds to the interval between the i-th LP-SS and the (i+1)th LP-SS in the LP-SS group. In addition, the D_i value can be the same or different depending on i, or can be a predefined value or a value set / instructed from the base station.

[0342] The example in Fig. 25(b) shows a relative time offset referenced to the first LP-SS location associated with the first SSB, but the offset value for each LP-SS resource may also be set / indicated via a relative time offset referenced to the starting point of the LP-SS group.

[0343] The table below shows examples of predefined combinations of offset values ​​that can be applied to the example of Fig. 25(a). The number of indices and / or the respective offset values ​​are exemplary, and other numbers and / or other values ​​may be applied. In addition, other units (e.g., SFN / slot / symbol) may be applied as the unit of offsets. The indices in the table can be set / instructed to the terminal through higher layer signaling (e.g., RRC signaling or SIBx (e.g., x=1)).

[0344] Index offset_slot (slot) offset_0 (symbol) offset_1 (symbol) offset_2 (symbol) 110 222 10243 10224 10245 10426 10447 10428 10449 1222 101224 111222 121224 131242 141244 151242 16 1244 17 2022 18 2024 19 2022 20 242 120 4222 20 4423 20 4224 20 4425 2222 26 2224 27 22222 8 2224 29 2242 30 2244 3122423 2224 244

[0345] Example 1-6

[0346] LP-SS resources can be configured / indicated through time offsets between individual LP-SSs within an LP-SS group from the SSB burst start point.

[0347] Unlike in embodiment 1-5, where the LP-SS group starting point (or the first LP-SS position) is referenced, in this embodiment, the SSB burst starting point (or the first SSB position) is referenced, and a relative time offset (e.g., in SFN / slot / symbol units) for the time resources of each LP-SS within the LP-SS group can be set / indicated.

[0348] FIG. 26 is a diagram showing an example of a time offset for each LP-SS within an LP-SS group according to the present disclosure.

[0349] The example in Fig. 26 shows a case where the first SSB (starting point) is referenced, but a time offset for each LP-SS may also be set / indicated similarly when the starting point of an SSB burst is referenced.

[0350] These time offset parameters may be set / indicated to the terminal via higher layer signaling (e.g., RRC signaling, SIB(1)), similar to Embodiments 1-1-1 and 1-1-2, or an index corresponding to a predefined combination of offset values ​​may be set / indicated to the terminal via higher layer signaling (e.g., RRC signaling, SIB(1)).

[0351] The table below shows examples of predefined combinations of offset values ​​for LP-SSs. The number of indices and / or the respective offset values ​​are exemplary, and other numbers and / or other values ​​may be applied. In addition, other units (e.g., SFN / slot / symbol) may be applied as the unit of offsets. The indices in the table can be set / instructed to the UE through higher layer signaling (e.g., RRC signaling or SIBx (e.g., x=1)).

[0352] Index offset_0 (slot) offset_1 (slot) offset_2 (slot) 1101213210121431014154101416

[0353] Example 1-7

[0354] LP-SS resources can be set / indicated through a time offset from each SSB starting point within an SSB burst to each corresponding LP-SS starting point within an LP-SS group.

[0355] Unlike in Embodiments 1-6 where the reference timing of the offset for each LP-SS is common (e.g., the SSB burst start point or the first SSB start point), in the present embodiment, the reference timing of the offset for each LP-SS may be different. Here, the association between an SSB and an LP-SS (corresponding to the same beam or QCLed to the same reference signal) may be separately set / indicated via higher layer signaling (e.g., RRC signaling or SIBx (e.g., x=1)), or a pre-defined rule may be applied that assumes that the SSB index and the LP-SS index are mutually associated if they are the same.

[0356] FIG. 27 is a diagram illustrating an example of a time offset from an associated SSB for each LP-SS within an LP-SS group according to the present disclosure.

[0357] For example, a time offset from the start of an SSB associated with each LP-SS constituting an LP-SS group to the start of the LP-SS may be set / indicated. Alternatively, the individual time offset for each LP-SS may be the difference between the slot in which the SSB is located and the slot in which the LP-SS associated with the SSB (on the same beam) is located. Alternatively, the individual time offset for each LP-SS may be the difference between the end point of each SSB included in an SSB burst and the start / end point of the LP-SS associated with the SSB. Alternatively, the individual time offset for each LP-SS may be the difference between the start point of each SSB included in an SSB burst and the end point of the LP-SS associated with the SSB. These offsets may be set / indicated on a SFN / slot / symbol basis, or may be set / indicated in the form of a combination of SFN / slot / symbol.

[0358] Here, each offset (e.g., offset_0, offset_1, offset_2) may be set / indicated via higher layer signaling (e.g., RRC signaling, SIB) or may be set / indicated via pre-defined rules.

[0359] For example, the offset value can be derived according to the formula offset_k = offset_0 + k*(DX) (where k = 0, 1, 2, ..., N-1). Here, offset_k is the offset from the kth SSB to the kth LP-SS (e.g., in units of SFN / slot / symbol). offset_0 is the offset from the first SSB to the first LP-SS. k corresponds to the index of the SSB within the (SSB burst) or the index of the LP-SS within the (LP-SS group). D corresponds to the number of OFDM symbols constituting the LP-SS. N corresponds to the number of SSBs included in the SSB burst (transmitted on different beams) or the number of LP-SSs included in the LP-SS group (transmitted on different beams). X corresponds to the number of OFDM symbols occupied by the SSBs. Additionally, offset_0 can be expressed in units of SFN / slot / symbol or as an absolute time length value (e.g., ms), the unit of k*(DX) in the above formula can be expressed in units of OFDM symbols, and offset_k can be expressed in the form of a combination of SFN / slot / symbol.

[0360] For example, if offset_0 is expressed by a combination of 1 subframe and 2 slots, and D, the number of OFDM symbols constituting the LP-SS, is 8, then offset_1 can be expressed as a time offset of 1 subframe, 2 slots, and 4 symbols according to the above-described formula. For example, in an NR communication system, since the duration of one SSB is 4 OFDM symbols, 4 can be applied as the value of X.

[0361] These time offset parameters may be set / indicated to the terminal via higher layer signaling (e.g., RRC signaling, SIBx (e.g., x=1)), or an index corresponding to a predefined combination of offset values ​​may be set / indicated to the terminal via higher layer signaling (e.g., RRC signaling, SIBx (e.g., x=1)), similar to Embodiments 1-1-1 and 1-1-2.

[0362] The table below shows examples of predefined combinations of offset values ​​for LP-SSs. The number of indices and / or the respective offset values ​​are exemplary, and other numbers and / or other values ​​may be applied. In addition, other units (e.g., SFN / slot / symbol) may be applied as the unit of offsets. The indices in the table can be set / instructed to the UE through higher layer signaling (e.g., RRC signaling or SIBx (e.g., x=1)).

[0363] Index offset_0 (slot) offset_1 (slot) offset_2 (slot) 1101214210121431014164101416

[0364] The various examples of the aforementioned Embodiment 1 may be based on the assumption of a one-to-one association between SSB and LP-SS (i.e., association with the same beam, or with the same reference signal and QCL). Alternatively, an association between a subset of SSBs and LP-SS (i.e., a many-to-one association in terms of SSB to LP-SS) may also be applied.

[0365] In this case, the resources of the LP-SS can be configured / indicated in the same manner as in the examples described above, where the resources of the LP-SS group are configured / indicated from individual SSBs, by replacing the SSBs with SSB subsets. For example, it can be assumed that an SSB burst includes eight SSBs (SSB#0, SSB#1, ..., SSB#7), an LP-SS group includes four LP-SSs (LP-SS#0, LP-SS#1, LP-SS#2, LP-SS#3), and the SSBs and LP-SSs are associated 2:1. For example, SSB#0 and SSB#1 can be associated with LP-SS#0, SSB#2 and SSB#3 can be associated with LP-SS#1, SSB#4 and SSB#5 can be associated with LP-SS#2, and SSB#6 and SSB#7 can be associated with LP-SS#3. Here, according to examples in which resources of an LP-SS group are set / indicated from individual SSBs, offset values ​​for LP-SS can be set / indicated by referring to an SSB with a lower index among associated SSBs or an SSB transmitted first in the time domain. For example, the position of LP-SS#0 is determined by the setting / indication of the offset value of the above-described example from SSB#0 (e.g., the offset value from the associated SSB to the LP-SS in the LP-SS group), and LP-SS#1 can be set / indicated by referring to SSB#2, LP-SS#2 can be set / indicated by referring to SSB#4, and LP-SS#3 can be set / indicated by referring to SSB#6, respectively.

[0366] Additionally or alternatively, although the examples described above assume that all SSBs within an SSB burst are transmitted, only some SSBs within an SSB burst may be transmitted. These some SSBs can be set / indicated via a parameter such as ssb-PositionInBurst. For example, the ssb-PositionInBurst parameter can be set / indicated to the terminal via SIB1, and can indicate whether to transmit for each SSB index in bitmap form. If only some SSBs are transmitted within an SSB burst, the offset value for LP-SS, as described above, can also be set / indicated with reference to the actually transmitted SSB.

[0367] For example, in the above-described examples, when the resources of the LP-SS group are set / indicated from each SSB (i.e., when the resources of the LP-SS within the LP-SS group are set / indicated from the associated SSB), the LP-SS can be associated with the SSB subset unit according to the SSB actually transmitted, and the LP-SS resources within the LP-SS group can be set / indicated by referencing the SSB actually transmitted through the ssb-PositionInBurst parameter. For example, let's assume that there are 8 SSBs (SSB#0, SSB#1, ..., SSB#7) in an SSB burst, 4 LP-SSs (LP-SS#0, LP-SS#1, LP-SS#2, LP-SS#3) in an LP-SS group, and the ssb-PositionInBurst parameter indicates that SSB#0, SSB#2, SSB#4, and SSB#6 are actually transmitted SSBs. In this case, SSB#0 is associated with LP-SS#0, SSB#2 is associated with LP-SS#1, SSB#4 is associated with LP-SS#2, and SSB#6 is associated with LP-SS#3, and resources of LP-SSs in the LP-SS group can be configured / indicated based on offset values ​​according to the examples described above.

[0368] In a communication system utilizing LP-WUS, the SSB period used in NR may be different from the LP-SS period. In a low-power communication system utilizing LP-WUS, the LP-SS period may be significantly longer than the SSB period. In this case, according to the examples described above, time-frequency resources for an LP-SS group (or an individual LP-SS within an LP-SS group) may be set / indicated based on the SSB burst (or an individual SSB within an SSB burst) immediately before transmitting the LP-SS group, regardless of the SSB period and the LP-SS period.

[0369] In addition, the symbol length occupied by the LP-SS may vary depending on the waveform used as the LP-SS. Therefore, the base station can set / indicate an appropriate time offset according to a parameter related to the waveform of the LP-SS (e.g., the M value in the OOK-4 waveform). For example, in the case of embodiment 1-1, the symbol duration of the LP-SS may occupy resources until the next subsequent slot. For example, when the OOK-1 or OOK-4 waveform with M=1 is used as the LP-SS, a longer symbol duration may be applied compared to other waveforms in order to satisfy the LP-SS sequence length. Therefore, the base station can set / indicate an appropriate time offset according to the LP-SS waveform.

[0370] In addition, as described above, the number of OFDM symbols occupied by the LP-SS may vary depending on the waveform used as the LP-SS. Accordingly, SSB burst and TDM (the remaining embodiments except for Embodiment 1-3) or FDM (Embodiment 1-3) may be set / indicated. For example, in the case of an LP-SS that occupies more OFDM symbols than SSB (for example, when 8 OFDM symbols are used as the LP-SS), when transmitted from the same symbol index as SSB, unlike an SSB burst that includes 2 SSBs in 1 slot, 2 LP-SSs may not be included in 1 slot. Therefore, in such cases, the resources of the LP-SS or the LP-SS group may be set / indicated in the SSB or SSB burst and TDM manner. Alternatively, for LP-SS using the same number of OFDM symbols as SSB, or when two LP-SSs are included in one slot, the resources of the LP-SS or LP-SS group can be set / indicated in SSB and FDM manner.

[0371] Example 2

[0372] The present embodiment relates to a method for transmitting / receiving an LP-SS group regardless of an SSB burst (or according to a reference other than an SSB burst).

[0373] Unlike in Embodiment 1, where the time resource of the LP-SS group can be set / indicated based on the interrelationship between the SSB burst and the LP-SS group, in Embodiment 2, the time resource of the LP-SS group can be set / indicated regardless of the SSB burst. Furthermore, unlike in Embodiment 1, where the LP-SS group can be configured in a similar form to the time resource of the SSB burst, in Embodiment 2, the time resource of the LP-SS can be set / indicated at the base station more flexibly (or without being affected by the SSB).

[0374] In the examples described below, it is assumed that the index / beam of an LP-SS within an LP-SS group is associated or linked to the index / beam of an SSB within an SSB burst in the same beam in order.

[0375] Example 2-1

[0376] LP-SS time resources can be set / indicated through time offsets for LP-SS groups that reference a specific time frame of the base station and time offsets for intervals between LP-SSs within the LP-SS group.

[0377] An offset_frame can be defined to the starting point of an LP-SS group with reference to the radio frame (or its boundary) within a radio frame managed by the base station itself (regardless of the SSB location). In addition, an offset_LP-SS, which is an offset between LP-SSs within the LP-SS group, can be defined.

[0378] FIG. 28 is a diagram illustrating an example of a time offset for an LP-SS group and an LP-SS based on a reference rather than an SSB burst according to the present disclosure.

[0379] For example, let's assume that the base station transmits an LP-SS with a period of 320ms, and a total of 4 LP-SSs are included in the LP-SS group (i.e., the SSB burst also includes 4 SSBs). In addition, 40ms can be set / indicated as offset_frame, and 2ms can be set / indicated as offset_LP-SS. In this case, the 4 LP-SSs can be located at {40ms, 42ms, 44ms, 46ms}.

[0380] Although the unit of offset based on radio frames is expressed in ms, it is not limited to this time unit and various time units such as symbol / slot / frame can be applied. For example, in the example above, offset_frame corresponds to the time offset from the start of the frame to the start of the LP-SS group, and offset_LP-SS corresponds to the time offset between the last symbol of one LP-SS and the first symbol of the next LP-SS.

[0381] Additionally, the starting symbol index of the first LP-SS within an LP-SS group may have the same starting symbol index within the slot according to the SCS as for SSB, or may be set / indicated via higher layer signaling (e.g., RRC signaling or SIBx (e.g., x=1)).

[0382] Example 2-2

[0383] LP-SS time resources can be set / indicated through a time offset for an LP-SS group that references a specific time frame of the base station and a time offset for the interval between each LP-SS within the LP-SS group.

[0384] In this embodiment, unlike the aforementioned embodiment 2-1, the interval between LP-SSs within an LP-SS group can be set / indicated more flexibly.

[0385] FIG. 29 is a diagram illustrating another example of a time offset for an LP-SS group and an LP-SS based on a reference other than an SSB burst according to the present disclosure.

[0386] In Embodiment 2-2, offset_frame can be defined in the same way as in Embodiment 2-1. Unlike Embodiment 2-1 in which the same offset_LP-SS is applied to LP-SSs within an LP-SS group, in Embodiment 2-2, the interval between LP-SSs can be independently / individually set / indicated. For example, if a total of four LP-SSs are included in an LP-SS group, a total of three offset_LP-SSs can be set / indicated. These offset_LP-SSs can be set / indicated through upper layer signaling (e.g., RRC signaling or SIBx (e.g., x=1)).

[0387] In the various examples of the present disclosure described above, slots / symbols / subframes / predetermined time lengths (ms) etc. are used as examples as units of time offset, but examples in which other time resource units (e.g., slot groups, symbol groups, subframe groups, etc.) are applied may also be included in the scope of the present disclosure.

[0388] Additionally, although in various embodiments of the present disclosure, the start and end points of the time offset have been described as the interval between an SSB burst and an LP-SS group or an LP-SS and the next LP-SS, examples in which other time offsets (e.g., an SSB index group and an LP-SS index group, an LP-SS group and the next LP-SS group, etc.) are applied may also be included in the scope of the present disclosure. For example, when there are one or more SSB index groups composed of N SSB indexes and when there are one or more LP-SS index groups composed of M LP-SS indexes, the above-described time offset can be applied between the SSB index groups and the LP-SS index groups. Here, N and M can be predefined or separately set through upper layer signaling, and N can also be M. For a further example, when there are one or more LP-SS index groups composed of M LP-SS indexes, the above-described time offset can be applied between the LP-SS index groups, and the value of M can likewise be predefined or separately set.

[0389] Additionally, in various embodiments of the present disclosure, PRBs have been used as examples of frequency offset units, but examples in which other frequency resource units (e.g., subcarriers, PRB / RB groups, subcarrier groups, etc.) are applied may also be included within the scope of the present disclosure.

[0390] Additionally, in various embodiments of the present disclosure, the reference position of the time / frequency offset of the LP-SS group is exemplified as the start position of an SSB burst in the time domain and the end position of the SSB burst in the frequency domain, but the scope of the present disclosure is not limited thereto, and includes examples of the start / end position of an SSB burst (or a specific SSB within the SSB burst) in the time domain, and / or the start / end position of an SSB burst (or a specific SSB within the SSB burst) in the frequency domain. That is, the scope of the present disclosure may include various variations in which the time / frequency position of the LP-SS group is set / indicated relative to the SSB burst.

[0391] 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.

[0392] 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 essential characteristics thereof. 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.

[0393] The scope of the present disclosure includes software or machine-executable instructions (e.g., an operating system, an application, firmware, a program, etc.) that cause operations according to the methods of various embodiments to be executed on a device or a computer, and a non-transitory computer-readable medium having such software or instructions stored thereon and executable on the device or computer. Instructions that can be used to program a processing system to perform the features described in the present disclosure can be stored on / in a storage medium or a computer-readable storage medium, and a computer program product including such a storage medium can be used to implement the features described in the present disclosure. The storage medium can include, but is not limited to, high-speed random access memory, such as DRAM, SRAM, DDR RAM, or other random access solid state memory devices, and can include non-volatile memory, such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid state storage devices. The memory optionally includes one or more storage devices remotely located from the processor(s). The memory or, alternatively, the non-volatile memory device(s) within the memory comprise a non-transitory computer-readable storage medium. The features described in this disclosure may be incorporated into software and / or firmware stored on any of the machine-readable media, which may control the hardware of the processing system and allow the processing system to interact with other mechanisms that utilize results according to embodiments of the present disclosure. Such software or firmware may include, but is not limited to, application code, device drivers, operating systems, and execution environments / containers.

[0394] Here, the wireless communication technology implemented in the device of the present disclosure may include not only LTE, NR, and 6G, but also Narrowband Internet of Things for low-power communication. For example, NB-IoT technology may be an example of LPWAN (Low Power Wide Area Network) technology and may be implemented with standards such as LTE Cat NB1 and / or LTE Cat NB2, and is not limited to the above-described names. Additionally or alternatively, the wireless communication technology implemented in the device of the present disclosure may perform communication based on LTE-M technology. For example, LTE-M technology may be an example of LPWAN technology and may be called by various names such as eMTC (enhanced Machine Type Communication). For example, LTE-M technology can be implemented by at least one of various standards such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL (non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine Type Communication, and / or 7) LTE M, and is not limited to the above-described names. Additionally or alternatively, the wireless communication technology implemented in the device (100, 200) of the present disclosure can include at least one of ZigBee, Bluetooth, and Low Power Wide Area Network (LPWAN) considering low-power communication, and is not limited to the above-described names. For example, ZigBee technology can create personal area networks (PAN) related to small / low-power digital communication based on various standards such as IEEE 802.15.4, and can be called by various names.

[0395] The method proposed in this disclosure is explained with a focus on examples applied to 3GPP LTE / LTE-A, 5G, and 6G systems, but can be applied to various wireless communication systems in addition to 3GPP LTE / LTE-A, 5G, and 6G systems.

Claims

1. A step of receiving one or more first synchronization signals (SS) from a network by a terminal within a first time interval; and A step of receiving one or more second synchronization signals (SS) from the network by the terminal within a second time interval, A method wherein the resource locations of the second time interval or one or more of the second SSs are based on the resource locations of the first time interval or one or more of the first SSs.

2. In paragraph 1, A method wherein information including values ​​of one or more offset parameters for one or more resource locations of the second time interval or one or more of the second SSs is set or instructed for the terminal.

3. In paragraph 2, The above information is, a first offset parameter between the starting point of the first time interval and the starting point of the second time interval, and A method comprising a second offset parameter between a starting point of the second time interval and a starting point of a first second SS among the one or more second SSs.

4. In paragraph 2, The above information is, a first offset parameter between the starting point of the first time interval and the starting point of the second time interval, and A method comprising a second offset parameter between an end point of a first second SS and a start point of a second second SS among the one or more second SSs.

5. In paragraph 2, The above information is, a frequency offset parameter between the one or more first SSs and the one or more second SSs, a first time offset parameter between the starting point of the first time interval and the starting point of the second time interval, and A method comprising a second time offset parameter between a starting point of the second time interval and a starting point of a first second SS among the one or more second SSs.

6. In paragraph 2, The above information is, A first offset parameter between the starting point of the first time interval and the starting point of the second time interval, a second offset parameter between the starting point of the second time interval and the starting point of the first second SS among the one or more second SSs, and A method comprising a third offset parameter between an end point of a first second SS and a start point of a second second SS among the one or more second SSs.

7. In paragraph 2, The above information is, A first offset parameter between the starting point of the first time interval and the starting point of the second time interval, a second offset parameter between the starting point of the second time interval and the starting point of the first second SS among the one or more second SSs, and A method comprising one or more third offset parameters for the spacing between successive second SSs.

8. In paragraph 2, The above information is, A first offset parameter between the starting point of the first time interval and the starting point of the second time interval, a second offset parameter between the starting point of the second time interval and the starting point of the first second SS among the one or more second SSs, and A method comprising at least one third offset parameter between a starting point of the first second SS and a starting point of each of the remaining one or more second SSs.

9. In paragraph 2, The above information is, A method comprising an offset parameter between a starting point of a first first SS among the one or more first SSs and a starting point of each of the k (k=0, 1, 2, ...)-th second SSs.

10. In paragraph 2, The above information is, A method comprising an offset parameter between the starting point of the k (k=0, 1, 2, ...)-th first SS and the starting point of the k-th second SS.

11. In paragraph 1, A method wherein said one or more first SSs are associated one-to-one with said one or more second SSs.

12. In paragraph 1, The first time interval includes a plurality of first SSs corresponding to different indices or beams, A method wherein the second time interval comprises a plurality of second SSs corresponding to different indices or beams.

13. In paragraph 1, A method wherein the second SS is received by a low power wake-up receiver (LP-WUR) of the terminal.

14. In paragraph 1, The above first SS is included in a synchronization signal block (SSB), The method wherein the second SS is a low power-SS (LP-SS).

15. In paragraph 1, The above first time interval corresponds to the SSB burst, The above second time interval corresponds to the LP-SS group, method.

16. One or more transceivers; and comprising one or more processors connected to said one or more transceivers, One or more of the above processors: Receiving one or more first synchronization signals (SS) from the network via the one or more transceivers within the first time interval; and is configured to receive one or more second synchronization signals (SS) from the network via the one or more transceivers within the second time interval; A terminal wherein the resource location of one or more of the second time intervals or one or more of the second SSs is based on the resource location of one or more of the first time intervals or one or more of the first SSs.

17. A step of transmitting one or more first synchronization signals (SS) to a terminal by a base station within a first time interval; and A step of transmitting one or more second synchronization signals (SS) to the terminal by the base station within the second time interval, A method wherein the resource locations of the second time interval or one or more of the second SSs are based on the resource locations of the first time interval or one or more of the first SSs.

18. One or more transmitters and receivers; and comprising one or more processors connected to said one or more transceivers, One or more of the above processors: Transmitting one or more first synchronization signals (SS) to a terminal via one or more transceivers within a first time interval; and It is set to transmit one or more second synchronization signals (SS) to the terminal through the one or more transceivers within the second time interval, A base station, wherein the resource locations of the second time interval or one or more of the second SSs are based on the resource locations of the first time interval or one or more of the first SSs.

19. One or more processors; and A processing device comprising one or more computer memories operatively connected to said one or more processors and storing instructions for performing a method according to any one of claims 1 to 15 based on execution by said one or more processors.

20. One or more non-transitory computer-readable media storing one or more instructions that are executed by one or more processors to control the performance of a method according to any one of claims 1 to 15.

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