Device and method for transmitting synchronization signal in wireless communication system

Abstract

The purpose of the present disclosure is to transmit a synchronization signal in a wireless communication system, and a method performed by a base station may comprise the steps of: generating at least one sequence for a synchronization signal; generating the synchronization signal on the basis of the at least one sequence; determining resources for transmitting the synchronization signal; determining directions for transmitting the synchronization signal; and transmitting the synchronization signal in the directions by using the resources.

Description

Device and method for transmitting a synchronization signal in a wireless communication system

[0001] The present disclosure relates to a wireless communication system, and to a device and method for transmitting a synchronization signal in a wireless communication system.

[0002] Wireless access systems are widely deployed to provide various types of communication services, such as voice and data. Typically, wireless access systems are multiple access systems that support communications with multiple users by sharing available system resources (e.g., bandwidth, transmission power). Examples of multiple access systems include code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), and single-carrier frequency division multiple access (SC-FDMA).

[0003] In particular, as numerous communication devices demand greater communication capacity, enhanced mobile broadband (eMBB) communication technologies are being proposed, improving upon existing radio access technology (RAT). Furthermore, massive machine type communications (mMTC), which connects multiple devices and objects to provide diverse services anytime and anywhere, as well as communication systems that consider reliability and latency-sensitive services / user equipment (UE), are being proposed. Various technological configurations are being proposed for these solutions.

[0004] The present disclosure relates to a device and method for effectively transmitting a synchronization signal in a wireless communication system.

[0005] The present disclosure relates to a device and method for expanding coverage in a wireless communication system.

[0006] The present disclosure relates to a device and method for expanding coverage by using a device that transmits or reflects a signal of a base station in a wireless communication system.

[0007] The present disclosure relates to a device and method for transmitting a synchronization signal using multi-beams at a base station in a wireless communication system.

[0008] The present disclosure relates to a device and method for simultaneously forming a beam toward the coverage area of ​​a base station and a beam toward an auxiliary device in a wireless communication system.

[0009] The technical objectives to be achieved in the present disclosure are not limited to those mentioned above, and other technical tasks not mentioned can be considered by a person having ordinary skill in the technical field to which the technical configuration of the present disclosure is applied from the embodiments of the present disclosure described below.

[0010] As an example of the present disclosure, a method performed by a base station in a wireless communication system may include the steps of generating at least one sequence for a synchronization signal, generating the synchronization signal based on the at least one sequence, determining resources for transmitting the synchronization signal, determining directions for transmitting the synchronization signal, and transmitting the synchronization signal in the directions using the resources. The synchronization signal may be transmitted via a multi-beam in at least one of a plurality of transmission opportunities, the multi-beam being capable of carrying the synchronization signal in a plurality of directions, including a first direction in which an adaptive beam for beam sweeping within a coverage area of ​​the base station is directed, and a second direction in which a fixed beam for an auxiliary node deployed within the coverage area of ​​the base station is directed.

[0011] As an example of the present disclosure, a method performed by a terminal in a wireless communication system may include the steps of determining resources for a synchronization signal, receiving the synchronization signal using the resources, obtaining synchronization for a base station using the synchronization signal, receiving system information from the base station, and performing a procedure for connection based on the system information. The synchronization signal may be transmitted by the base station via a multi-beam in at least one of a plurality of transmission opportunities, and the multi-beam may carry the synchronization signal in a plurality of directions, including a first direction toward which an adaptive beam for beam sweeping within the coverage of the base station is directed, and a second direction toward which a fixed beam for an auxiliary node deployed within the coverage of the base station is directed.

[0012] As an example of the present disclosure, in a wireless communication system, a base station may include a transceiver and a processor coupled to the transceiver, wherein the processor may be configured to generate at least one sequence for a synchronization signal, generate the synchronization signal based on the at least one sequence, determine resources for transmitting the synchronization signal, determine directions for transmitting the synchronization signal, and transmit the synchronization signal in the directions using the resources. The synchronization signal may be transmitted via a multi-beam in at least one of a plurality of transmission opportunities, and the multi-beam may carry the synchronization signal in a plurality of directions, including a first direction in which an adaptive beam for beam sweeping within a coverage area of ​​the base station is directed, and a second direction in which a fixed beam for an auxiliary node deployed within the coverage area of ​​the base station is directed.

[0013] As an example of the present disclosure, in a wireless communication system, a terminal includes a transceiver and a processor connected to the transceiver, wherein the processor is configured to determine resources for a synchronization signal, receive the synchronization signal using the resources, acquire synchronization for a base station using the synchronization signal, receive system information from the base station, and perform a procedure for connection based on the system information. The synchronization signal is transmitted by the base station via a multi-beam in at least one of a plurality of transmission opportunities, and the multi-beam can carry the synchronization signal in a plurality of directions including a first direction toward which an adaptive beam for beam sweeping within the coverage of the base station is directed, and a second direction toward which a fixed beam for an auxiliary node deployed within the coverage of the base station is directed.

[0014] As an example of the present disclosure, a communication device includes at least one processor, and at least one computer memory coupled to the at least one processor and storing instructions that, when executed by the at least one processor, direct operations, wherein the operations may include: generating at least one sequence for a synchronization signal; generating the synchronization signal based on the at least one sequence; determining resources for transmitting the synchronization signal; determining directions for transmitting the synchronization signal; and transmitting the synchronization signal in the directions using the resources. The synchronization signal may be transmitted via a multi-beam at least one of a plurality of transmission opportunities, the multi-beam being capable of carrying the synchronization signal in a plurality of directions, including a first direction in which an adaptive beam for beam sweeping within a coverage area of ​​the communication device is directed, and a second direction in which a fixed beam is directed for an auxiliary node deployed within the coverage area of ​​the communication device.

[0015] As an example of the present disclosure, a non-transitory computer-readable medium storing at least one instruction comprises at least one instruction executable by a processor, wherein the at least one instruction can instruct a device to generate at least one sequence for a synchronization signal, generate the synchronization signal based on the at least one sequence, determine resources for transmitting the synchronization signal, determine directions for transmitting the synchronization signal, and transmit the synchronization signal in the directions using the resources. The synchronization signal is transmitted via a multi-beam in at least one of a plurality of transmission opportunities, the multi-beam carrying the synchronization signal in a plurality of directions including a first direction in which an adaptive beam for beam sweeping within the coverage of the base station is directed, and a second direction in which a fixed beam is directed for an auxiliary node deployed within the coverage of the base station is directed.

[0016] The above-described aspects of the present disclosure are only some of the preferred embodiments of the present disclosure, and various embodiments reflecting the technical features of the present disclosure can be derived and understood by a person having ordinary skill in the art based on the detailed description of the present disclosure to be described below.

[0017] The following effects may be achieved by embodiments based on the present disclosure.

[0018] According to the present disclosure, synchronization signals can be effectively transmitted within coverage.

[0019] The effects that can be obtained from the embodiments of the present disclosure are not limited to the effects mentioned above, and other effects not mentioned can be clearly derived and understood by those skilled in the art to which the technical configuration of the present disclosure is applied, from the description of the embodiments of the present disclosure below. In other words, unintended effects resulting from implementing the configuration described in the present disclosure can also be derived from the embodiments of the present disclosure by those skilled in the art.

[0020] The accompanying drawings are intended to aid understanding of the present disclosure and, together with detailed descriptions, may provide embodiments of the present disclosure. However, the technical features of the present disclosure are not limited to specific drawings, and the features disclosed in each drawing may be combined with each other to form new embodiments. Reference numerals in each drawing may indicate structural elements.

[0021] Figure 1 illustrates an example of a communication system applicable to the present disclosure.

[0022] FIG. 3 illustrates an example of a wireless device applicable to the present disclosure.

[0023] FIG. 3 illustrates a method for processing a transmission signal applicable to the present disclosure.

[0024] FIG. 4 illustrates an example of a communication structure that can be provided in a 6G (6th generation) system applicable to the present disclosure.

[0025] Figure 4 illustrates a communication procedure between a terminal and a base station applicable to the present disclosure.

[0026] FIG. 5 illustrates an example of a communication structure that can be provided in a 6G (6th generation) system applicable to the present disclosure.

[0027] Figure 6 illustrates an electromagnetic spectrum applicable to the present disclosure.

[0028] Figure 7 illustrates a THz communication method applicable to the present disclosure.

[0029] Figure 8 illustrates a THz signal generation method applicable to the present disclosure.

[0030] FIG. 9 illustrates a wireless communication transceiver applicable to the present disclosure.

[0031] Figure 10 illustrates a transmitter structure applicable to the present disclosure.

[0032] Figure 11 illustrates a system information transmission procedure applicable to the present disclosure.

[0033] Figure 12 illustrates a beam management procedure applicable to the present disclosure.

[0034] FIG. 13 illustrates an example of an environment in which communication technologies according to one embodiment of the present disclosure are applied.

[0035] FIG. 14a illustrates an example of the structure of RIS according to one embodiment of the present disclosure.

[0036] FIG. 14b illustrates an example of the structure of an NCR according to one embodiment of the present disclosure.

[0037] Figure 15 illustrates an example of beam sweeping for transmitting SSB (synchronization signal / physical broadcasting channel block) in an environment where NCR is deployed.

[0038] Figure 16a illustrates an example of beam operation for transmitting SSBs in an environment where NCRs are deployed.

[0039] Figure 16b illustrates an example of how the number of required SSB transmission opportunities varies depending on the number of NCRs.

[0040] FIGS. 17A and 17B illustrate examples of structures for forming multi-beams according to one embodiment of the present disclosure.

[0041] FIGS. 18A and 18B illustrate examples of parallel beam sweeping of a base station and an auxiliary node in which different signals are transmitted in chains according to one embodiment of the present disclosure.

[0042] FIGS. 19A and 19B illustrate examples of parallel beam sweeping of a base station and an auxiliary node in which identical signals are transmitted in chains according to one embodiment of the present disclosure.

[0043] FIG. 20 illustrates examples of wide beams of different shapes according to one embodiment of the present disclosure.

[0044] FIGS. 21A and 21B illustrate the number of beams required for beam sweeping when applying a multi-beam method using multiple chains according to one embodiment of the present disclosure.

[0045] Figures 22a and 22b illustrate examples of beam cancellation phenomena according to control of two antenna elements.

[0046] Figure 23 shows examples of various beam patterns according to control of multiple antenna elements.

[0047] FIG. 24 illustrates an example of beamforming using a non-uniform phase front in an antenna array according to one embodiment of the present disclosure.

[0048] FIGS. 25A to 25D illustrate examples of configurations of an antenna array for multi-beam beamforming according to one embodiment of the present disclosure.

[0049] FIGS. 26A to 26C illustrate graphs showing the performance of a multi-beam forming technique according to one embodiment of the present disclosure.

[0050] FIGS. 27A and 27B illustrate three-dimensional views of three beams formed using a multi-beam forming technique according to one embodiment of the present disclosure.

[0051] FIGS. 28A and 28B illustrate three-dimensional views of four beams formed using a multi-beam forming technique according to one embodiment of the present disclosure.

[0052] FIGS. 29A and 29B illustrate three-dimensional views of five beams formed using a multi-beam forming technique according to one embodiment of the present disclosure.

[0053] FIG. 30 illustrates the number of beams required for beam sweeping when applying a multi-beam method using a single chain according to one embodiment of the present disclosure.

[0054] FIG. 31 illustrates an example of a procedure for transmitting a synchronization signal according to one embodiment of the present disclosure.

[0055] FIG. 32 illustrates an example of a procedure for receiving a synchronization signal according to one embodiment of the present disclosure.

[0056] FIG. 33 illustrates an example of a random access procedure according to one embodiment of the present disclosure.

[0057] FIG. 34 illustrates an example of a random access procedure using an auxiliary node according to one embodiment of the present disclosure.

[0058] FIG. 35 illustrates an example of a beam management procedure according to one embodiment of the present disclosure.

[0059] Figure 36 illustrates an example of a wireless device applicable to the present disclosure.

[0060] Figure 37 illustrates an example of a portable device applicable to the present disclosure.

[0061] Figure 38 illustrates an example of a vehicle or autonomous vehicle applicable to the present disclosure.

[0062] Figure 39 illustrates an example of a vehicle applicable to the present disclosure.

[0063] Figure 40 illustrates an example of an XR device applicable to the present disclosure.

[0064] Figure 41 illustrates an example of a robot applicable to the present disclosure.

[0065] Figure 42 illustrates an example of an AI device applicable to the present disclosure.

[0066] The following embodiments combine the components and features of the present disclosure in a predetermined form. Each component or feature may be considered optional unless explicitly stated otherwise. Each component or feature may be implemented without being combined with other components or features. Furthermore, some components and / or features may be combined to form embodiments of the present disclosure. 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.

[0067] In the description of the drawings, procedures or steps that may obscure the gist of the present disclosure are not described, and procedures or steps that can be understood by a person skilled in the art are also not described.

[0068] Throughout the specification, when a part is said to "comprising" or "including" a component, this does not mean that other components may be included, but rather that other components may be excluded, unless otherwise specifically stated. In addition, terms such as "...part," "...unit," and "module" described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware, software, or a combination of hardware and software. In addition, the words "a" or "an," "one," "the," and similar related words may be used in the context of describing the present disclosure (especially in the context of the claims below) to include both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context.

[0069] Embodiments of the present disclosure described herein focus on the data transmission and reception relationship between a base station and a mobile station. Here, the base station is understood as a terminal node of a network that directly communicates with the mobile station. Certain operations described herein as being performed by the base station may, in some cases, be performed by an upper node of the base station.

[0070] That is, in a network consisting of multiple network nodes including a base station, various operations performed for communication with a mobile station may be performed by the base station or other network nodes other than the base station. In this case, the term 'base station' may be replaced by terms such as fixed station, Node B, eNB (eNode B), gNB (gNode B), ng-eNB, advanced base station (ABS), or access point.

[0071] Additionally, in the embodiments of the present disclosure, the term terminal may be replaced with terms such as user equipment (UE), mobile station (MS), subscriber station (SS), mobile subscriber station (MSS), mobile terminal, or advanced mobile station (AMS).

[0072] Additionally, a transmitter refers to a fixed and / or mobile node that provides data or voice services, and a receiver refers to a fixed and / or mobile node that receives data or voice services. Therefore, for uplink, a mobile station can be the transmitter, and a base station can be the receiver. Similarly, for downlink, a mobile station can be the receiver, and a base station can be the transmitter.

[0073] Embodiments of the present disclosure may be supported by standard documents disclosed in at least one of wireless access systems, such as IEEE 802.xx system, 3rd Generation Partnership Project (3GPP) system, 3GPP Long Term Evolution (LTE) system, 3GPP 5th generation (5G) NR (New Radio) system and 3GPP2 system, and in particular, embodiments of the present disclosure may be supported by 3GPP TS (technical specification) 38.211, 3GPP TS 38.212, 3GPP TS 38.213, 3GPP TS 38.321 and 3GPP TS 38.331 documents.

[0074] Furthermore, the embodiments of the present disclosure can be applied to other wireless access systems and are not limited to the systems described above. For example, they can be applied to systems implemented after the 3GPP 5G NR system and are not limited to a specific system.

[0075] That is, obvious steps or parts not described in the embodiments of the present disclosure can be explained by referring to the above documents. In addition, all terms disclosed in this document can be explained by the above standard documents.

[0076] Hereinafter, preferred embodiments according to 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 illustrate exemplary embodiments of the present disclosure and is not intended to represent the only embodiments in which the technical configurations of the present disclosure may be implemented.

[0077] Additionally, specific terms used in the embodiments of the present disclosure are provided to aid in understanding of the present disclosure, and the use of such specific terms may be changed to other forms without departing from the technical spirit of the present disclosure.

[0078] The following technology can be applied to various wireless access 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).

[0079] For clarity, the following description is based on 3GPP communication systems (e.g., LTE, NR, etc.), but the technical spirit of the present disclosure is not limited thereto. LTE may refer to technology after 3GPP TS 36.xxx Release 8. Specifically, LTE technology after 3GPP TS 36.xxx Release 10 may be referred to as LTE-A, and LTE technology after 3GPP TS 36.xxx Release 13 may be referred to as LTE-A pro. 3GPP NR may refer to technology after TS 38.xxx Release 15. 3GPP 6G may refer to technology after TS Release 17 and / or Release 18. "xxx" refers to a standard document detail number. LTE / NR / 6G may be collectively referred to as a 3GPP system.

[0080] For background information, terms, abbreviations, etc. used in this disclosure, reference may be made to standard documents published prior to this disclosure. For example, reference may be made to standard documents 36.xxx and 38.xxx.

[0081]

[0082] Communication system applicable to the present disclosure

[0083] Although not limited thereto, the various descriptions, functions, procedures, proposals, methods and / or operational flowcharts of the present disclosure disclosed in this document may be applied to various fields requiring wireless communication / connectivity (e.g., 5G) between devices.

[0084] Hereinafter, more specific examples will be provided with reference to the drawings. In the drawings / descriptions below, the same drawing reference numerals may represent identical or corresponding hardware blocks, software blocks, or functional blocks, unless otherwise described.

[0085] Figure 1 illustrates an example of a communication system applied to the present disclosure.

[0086] Referring to FIG. 1, a communication system (100) applied to the present disclosure includes a wireless device, a base station, and a network. Here, the wireless device 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 device. Although not limited thereto, the wireless device may include a robot (100a), a vehicle (100b-1, 100b-2), an XR (extended reality) device (100c), a hand-held device (100d), a home appliance (100e), an IoT (Internet of Things) device (100f), and an AI (artificial intelligence) device / server (100g). 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 vehicles (100b-1, 100b-2) may include unmanned aerial vehicles (UAVs) (e.g., drones). The XR devices (100c) include augmented reality (AR) / virtual reality (VR) / mixed reality (MR) devices, and may be implemented in the form of head-mounted devices (HMDs), head-up displays (HUDs) installed in vehicles, televisions, smartphones, computers, wearable devices, home appliances, digital signage, vehicles, robots, etc. The portable devices (100d) may include smartphones, smart pads, wearable devices (e.g., smartwatches, smart glasses), computers (e.g., laptops, etc.), etc. The home appliances (100e) may include TVs, refrigerators, washing machines, etc. The IoT devices (100f) may include sensors, smart meters, etc.For example, the base station (120) and the network (130) may also be implemented as wireless devices, and a specific wireless device (120a) may act as a base station / network node to other wireless devices.

[0087] Wireless devices (100a to 100f) can be connected to a network (130) via a base station (120). AI technology can be applied to the wireless devices (100a to 100f), and the wireless devices (100a to 100f) can be connected to an AI server (100g) 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 (100a to 100f) can communicate with each other via the base station (120) / network (130), but can also communicate directly (e.g., sidelink communication) without going through the base station (120) / network (130). For example, vehicles (100b-1, 100b-2) can communicate directly (e.g., V2V (vehicle to vehicle) / V2X (vehicle to everything) communication). Additionally, an IoT device (100f) (e.g., a sensor) can communicate directly with another IoT device (e.g., a sensor) or another wireless device (100a to 100f).

[0088] Wireless communication / connection (150a, 150b, 150c) can be established between wireless devices (100a to 100f) / base stations (120), and base stations (120) / base stations (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 base station-to-base station communication (150c) (e.g., relay, IAB (integrated access backhaul)). Through the wireless communication / connection (150a, 150b, 150c), the wireless device and base station / wireless device, and base stations and base stations can transmit / receive wireless signals to / from 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 proposals 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.

[0089] Devices applicable to the present disclosure

[0090] FIG. 2 illustrates an example of a wireless device applicable to the present disclosure.

[0091] Referring to FIG. 2, 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).

[0092] 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.

[0093] Hereinafter, the hardware elements of the wireless device (200) will be described in more detail. Although not limited thereto, at least one protocol layer may be implemented by at least one processor (202). For example, at least one processor (202) may implement at least one layer (e.g., a functional layer such as physical (PHY), media access control (MAC), radio link control (RLC), packet data convergence protocol (PDCP), radio resource control (RRC), and service data adaptation protocol (SDAP)). At least one processor (202) may generate at least one Protocol Data Unit (PDU) and / or at least one Service Data Unit (SDU) according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. At least one processor (202) may generate a message, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. At least one processor (202) can generate a signal (e.g., a baseband signal) including a PDU, an SDU, a message, control information, data or information according to the functions, procedures, proposals and / or methods disclosed in this document, and provide the signal to at least one transceiver (206). At least one processor (202) can receive a signal (e.g., a baseband signal) from at least one transceiver (206) and obtain the PDU, SDU, message, control information, data or information according to the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed in this document.

[0094] 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.

[0095] 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.

[0096] At least one transceiver (206) can transmit user data, control information, wireless signals / channels, etc., mentioned in the methods and / or flowcharts of this document to at least one other device. At least one transceiver (206) can receive user data, control information, wireless signals / channels, etc. mentioned in the descriptions, functions, procedures, proposals, methods and / or flowcharts disclosed in this document from at least one other device. For example, at least one transceiver (206) can be connected to at least one processor (202) and can transmit and receive wireless signals. For example, at least one processor (202) can control at least one transceiver (206) to transmit user data, control information, or wireless signals to at least one other device. Furthermore, at least one processor (202) can control at least one transceiver (206) to receive user data, control information, or wireless signals from at least one other device. In addition, at least one transceiver (206) may be connected to at least one antenna (208), and at least one transceiver (206) may be configured to transmit and receive user data, control information, wireless signals / channels, etc. mentioned in the descriptions, functions, procedures, proposals, methods and / or operation flowcharts disclosed in this document through at least one antenna (208). In this document, at least one antenna may be a plurality of physical antennas or a plurality of logical antennas (e.g., antenna ports). At least one transceiver (206) may convert the received wireless signals / channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, wireless signals / channels, etc. using at least one processor (202). At least one transceiver (206) may convert the processed user data, control information, wireless signals / channels, etc. from baseband signals to RF band signals using at least one processor (202).For this purpose, at least one transceiver (206) may include an (analog) oscillator and / or filter.

[0097] The components of the wireless device described with reference to FIG. 2 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).

[0098] The structure of the wireless device described with reference to FIG. 2 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. 2 can be at least a portion of various devices described with reference to FIG. 1 (e.g., a robot (100a), a vehicle (100b-1, 100b-2), an XR device (100c), a portable device (100d), a home appliance (100e), an IoT device (100f), an AI device / server (100g)). Furthermore, according to various embodiments, in addition to the components illustrated in FIG. 2, the device may further include other components.

[0099] 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.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] The structure of the wireless device illustrated in FIG. 2 may be understood as a part of a RAN node (e.g., base station, DU, RU, RRㅗ, etc.). That is, the device illustrated in FIG. 2 may be a RAN node. In this case, the device may further include a wired transceiver for front haul and / or back haul communication. However, if the front haul and / or back haul communication is based on wireless communication, at least one transceiver (206) illustrated in FIG. 2 may be used for front haul and / or back haul communication, and a wired transceiver may not be included.

[0105]

[0106] FIG. 3 illustrates a method for processing a transmission signal applicable to the present disclosure. For example, the transmission signal may be processed by a signal processing circuit. At this time, the signal processing circuit (300) may include a scrambler (310), a modulator (320), a layer mapper (330), a precoder (340), a resource mapper (350), and a signal generator (360). At this time, as an example, the operations / functions of FIG. 3 may be performed in the processor (202) and / or the transceiver (206) of FIG. 2. Furthermore, as an example, the hardware elements of FIG. 3 may be implemented in the processor (202) and / or the transceiver (206) of FIG. 2. As an example, blocks 310 to 360 may be implemented in the processor (202) of FIG. 2. Additionally, blocks 310 to 350 may be implemented in the processor (202) of FIG. 2, and block 360 may be implemented in the transceiver (206) of FIG. 2, and are not limited to the above-described embodiment.

[0107] The codeword can be converted into a wireless signal through the signal processing circuit (300) of FIG. 3. Here, the codeword is an encoded bit sequence of an information block. The information block may include a transport block (e.g., a UL-SCH transport block, a DL-SCH transport block). Here, the information block may include data related to AI (e.g., training data, AI model data, input data, output data, etc.), and the codeword may be an encoded bit sequence corresponding to the data related to AI. The wireless signal may be transmitted through various physical channels (e.g., PUSCH, PDSCH). Specifically, the codeword may be converted into a bit sequence scrambled by a scrambler (310). The scramble sequence used for scrambling is generated based on an initialization value, and the initialization value may include ID information of the wireless device, etc. The scrambled bit sequence may be modulated into a modulation symbol sequence by a modulator (320). Modulation schemes may include pi / 2-BPSK (pi / 2-binary phase shift keying), m-PSK (m-phase shift keying), m-QAM (m-quadrature amplitude modulation), etc.

[0108] A complex modulation symbol sequence can be mapped to at least one transport layer by a layer mapper (330). Here, a transport layer is a logical resource unit for mapping a signal or data transmitted through spatial resources to antenna ports, and one transport layer can correspond to one stream or one antenna port. Each of the complex modulation symbols included in the complex modulation symbol sequence is mapped to at least one transport layer, thereby determining which antenna port it will be transmitted through. The modulation symbols of each transport layer can be mapped to the corresponding antenna port(s) by a precoder (340). The output z of the precoder (340) can be obtained by multiplying the output y of the layer mapper (330) by a precoding matrix W of NХM. Here, N is the number of antenna ports, and M is the number of transport layers. Here, the precoder (340) may perform precoding after performing transform precoding (e.g., discrete Fourier transform (DFT) transform) on complex modulation symbols. Additionally, the precoder (340) may perform precoding without performing transform precoding.

[0109] The resource mapper (350) can map modulation symbols of each antenna port to time-frequency resources. The time-frequency resources can include multiple symbols (e.g., CP-OFDMA symbols, DFT-s-OFDMA symbols) in the time domain and multiple subcarriers in the frequency domain. The signal generator (360) generates a wireless signal from the mapped modulation symbols, and the generated wireless signal can be transmitted to another device through each antenna. To this end, the signal generator (360) can include an inverse fast Fourier transform (IFFT) module, a cyclic prefix (CP) inserter, a digital-to-analog converter (DAC), a frequency uplink converter, and the like.

[0110] The signal processing process for a received signal in a wireless device may be configured in reverse order of the signal processing process (310 to 360) of FIG. 3. For example, a wireless device (e.g., 200 of FIG. 2) may receive a wireless signal from the outside through an antenna port / transceiver. The received wireless signal may be converted into a baseband signal through a signal restorer. For this purpose, the signal restorer may include a frequency downlink converter, an analog-to-digital converter (ADC), a CP remover, and a fast Fourier transform (FFT) module. Thereafter, the baseband signal may be restored to a codeword through a resource demapper process, a postcoding process, a demodulation process, and a descrambling process. The codeword may be restored to the original information block through decoding. Therefore, a signal processing circuit (not shown) for a received signal may include a signal restorer, a resource demapper, a postcoder, a demodulator, a descrambler, and a decoder.

[0111] Figure 4 illustrates a communication procedure between a terminal and a base station applicable to the present disclosure. Figure 4 illustrates operations of a terminal (410) and a base station (420) transmitting and / or receiving data and operations performed prior thereto.

[0112] Referring to FIG. 4, in step 401, the terminal (410) and the base station (420) perform synchronization. For example, the terminal (410) performs an initial cell search operation. Specifically, the terminal (410) can detect at least one synchronization signal transmitted from the base station (420) according to a predefined rule. Here, the synchronization signal can include multiple synchronization signals classified according to structure or purpose (e.g., primary synchronization signal, secondary synchronization signal). Through this, the terminal (410) can check the boundary of the frame, subframe, slot, and / or symbol of the base station (420) and obtain information about the base station (420) (e.g., cell identifier).

[0113] In step 403, the terminal (410) obtains system information transmitted from the base station (420). The system information is information related to the properties, characteristics, and / or capabilities of the base station (420) required to access the base station (420) and use the service, and may be classified by content (e.g., whether it is essential for access), transmission structure (e.g., channel used, whether provided on-demand), etc., and may be classified into, for example, a master information block (MIB) and a system information block (SIB). If necessary, the terminal (410) may transmit a signal requesting system information before receiving the system information. The system information may include information related to an AI function. For example, the system information may include at least one of information related to an AI model, information related to training, and information related to inference / prediction, as information required for operations performed based on AI. However, the request and provision of the system information may be performed after a random access procedure described below.

[0114] In step 405, the terminal (410) and the base station (420) perform a random access procedure. The terminal (410) may transmit and / or receive at least one message (e.g., a random access preamble, a random access response (RAR) message, etc.) for the random access procedure based on information related to the random access channel of the base station (420) obtained through system information (e.g., channel position, channel structure, supported preamble structure, etc.). For example, the terminal (410) may transmit a preamble (e.g., MSG1) through the random access channel, receive an RAR message (e.g., MSG2), transmit a message (e.g., MSG3) including information related to the terminal (410) (e.g., identification information) to the base station (420) using scheduling information included in the RAR message, and receive a message (e.g., MSG4) for contention resolution and / or connection establishment. As another example, MSG1 and MSG3 may be sent and received as one message, or MSG2 and MSG4 may be sent and received as one message.

[0115] In step 407, the terminal (410) and the base station (420) perform signaling of control information. Here, the control information may be defined in various layers, such as a layer that controls a connection (e.g., a radio resource control (RRC) layer), a layer that handles mapping between logical channels and transport channels (e.g., a media access control (MAC) layer), and a layer that handles physical channels (e.g., a physical (PHY) layer). For example, the terminal (410) and the base station (420) may perform at least one of signaling for establishing a connection, signaling for determining settings related to communication, and signaling for indicating allocated resources. In addition, the signaling of the control information may be performed to convey information related to an AI function. For example, the information related to an AI function is information necessary for an operation performed based on AI, and may include at least one of information related to an AI model, information related to training, and information related to inference / prediction. More specifically, information related to the AI ​​function signaled in step 407 may be combined and / or combined with information related to the AI ​​function signaled in step 403, and the two may be defined in a hierarchical, mutually complementary, or substitutive structure.

[0116] In step 409, the terminal (410) and the base station (420) transmit and / or receive data. In other words, the terminal (410) and the base station (420) can process, transmit, and / or receive data based on the signaling of the control information. For example, when transmitting data, the terminal (410) or the base station (420) can perform at least one of channel encoding, rate matching, scrambling, constellation mapping, layer mapping, waveform modulation, antenna mapping, and resource mapping on the information bits. Conversely, when receiving data, the terminal (410) or the base station (420) 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. Here, the transmitted data is data related to AI, and may include, for example, data for AI-based operations or data generated by AI-based operations.

[0117] Steps 401 to 409 illustrated with reference to FIG. 4 do not necessarily have to be performed in the order illustrated in FIG. 4, and the order of at least some of the steps may vary. Furthermore, at least some of steps 401 to 409 may be combined into a single step or omitted. That is, the steps illustrated in FIG. 4 may be performed in various modified forms.

[0118] 6G communication systems and core implementation technologies of 6G systems

[0119] The 5G system defines various operating bands within FR1 (frequency range 1), which covers 410 MHz to 7125 MHz, and FR2 (frequency range 2), which covers 24,250 MHz to 71,000 MHz. Various frequencies are being discussed as operating bands for the subsequent 6G system, and the use of higher frequencies than 5G systems is also being considered for wider bandwidth and higher transmission speeds. One such band is the THz (terahertz) frequency band, which covers approximately 100 GHz to 10 THz. The THz frequency band is a band that has both the transparency of radio waves and the straightness of light waves, and communications using the THz frequency band are expected to play a transitional role from existing radio-centered communications to lightwave-based communications.

[0120] 6G systems utilizing the THz frequency band have the following goals: 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 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,” and the 6G system can be designed to satisfy the requirements as shown in [Table 1] below.

[0121] Per device peak data rate1 TbpsE2E latency1 msMaximum spectral efficiency100 bps / HzMobility supportup to 1000 km / hrSatellite integrationFullyAIFullyAutonomous vehicleFullyXRFullyHaptic CommunicationFully

[0122] At this time, the 6G system may have key factors such as enhanced mobile broadband (eMBB), ultra-reliable low latency communications (URLLC), massive machine type communications (mMTC), AI integrated communication, tactile internet, high throughput, high network capacity, high energy efficiency, low backhaul and access network congestion, and enhanced data security. FIG. 5 illustrates an example of a communication structure that can be provided in a 6G system applicable to the present disclosure. Referring to FIG. 5, the 6G system is expected to have simultaneous wireless communication connectivity that is 50 times higher than that of a 5G wireless communication system. URLLC, a key feature of 5G, is expected to become an even more crucial technology in 6G communications, offering end-to-end latency of less than 1 ms. Furthermore, 6G systems will boast significantly higher volumetric spectral efficiency than the commonly used area spectral efficiency. 6G systems can offer extremely long battery life and advanced battery technologies for energy harvesting, eliminating the need for separate charging for mobile devices in 6G systems. New network characteristics in 6G may include:

[0123] - Satellite integrated network: 6G is expected to integrate with satellites to provide a global mobile network. The integration of terrestrial, satellite, and airborne networks into a single wireless communications system is crucial for 6G.

[0124] Connected Intelligence: Unlike previous generations of wireless communication systems, 6G is revolutionary, upgrading the wireless evolution from "connected objects" to "connected intelligence." AI can be applied at every stage of the communication process (or at every signal processing step, as described below).

[0125] - Seamless integration of wireless information and energy transfer: 6G wireless networks will transfer power to charge the batteries of devices such as smartphones and sensors. Therefore, wireless information and energy transfer (WIET) will be integrated.

[0126] - Ubiquitous super 3D connectivity: Access to networks and core network functions of drones and very low Earth orbit satellites will create super 3D connectivity in 6G ubiquitous.

[0127] Some general requirements for the new network characteristics of 6G, such as the above, may be as follows:

[0128] - Small cell networks: The concept of small cell networks was introduced to improve received signal quality in cellular systems by increasing throughput, energy efficiency, and spectral efficiency. Consequently, small cell networks are essential for 5G and beyond-5G (5GB) communication systems. Accordingly, 6G communication systems also adopt the characteristics of small cell networks.

[0129] Ultra-dense heterogeneous networks: Ultra-dense heterogeneous networks will be another key feature of 6G communication systems. Multi-tier networks comprised of heterogeneous networks improve overall QoS and reduce costs.

[0130] High-capacity backhaul: Backhaul connections are characterized by high-capacity backhaul networks to support high-volume traffic. High-speed fiber optics and free-space optics (FSO) systems may be potential solutions to this problem.

[0131] - Radar technology integrated with mobile technology: High-precision localization (or location-based services) through communications is a key feature of 6G wireless communication systems. Therefore, radar systems will be integrated with 6G networks.

[0132] - Softwarization and virtualization: Softwarization and virtualization are two critical features that form the foundation of the design process for 5GB networks to ensure flexibility, reconfigurability, and programmability. Furthermore, billions of devices can be shared on a shared physical infrastructure.

[0133] To satisfy the above-mentioned characteristics, the core implementation technologies of the 6G system may include artificial intelligence (AI), THz (terahertz) communication, optical wireless technology, FSO backhaul network, massive MIMO technology, blockchain, 3D networking, quantum communication, unmanned aerial vehicles, cell-free communication, wireless information and energy transfer (WIET), integration of sensing and communication, integration of access backhaul networks, holographic beamforming, big data analysis, and large intelligent surface (LIS).

[0134] For example, THz communication can be utilized in 6G systems. THz communication is a communication that utilizes a spectrum in a frequency band between 0.3 THz and 3 THz with a corresponding wavelength in the range of 0.1 mm to 1 mm, as shown in FIG. 6. Referring to FIG. 6, the frequency band of THz waves is located in the middle region between the infrared band and the millimeter wave band, and therefore, THz waves can be understood as radio waves with the shortest wavelength and light waves with the longest wavelength. Therefore, THz waves share some of the characteristics of infrared and microwave waves, and specifically, they can simultaneously have the transparency of electromagnetic waves and the straightness of light waves.

[0135]

[0136] Fig. 7 illustrates a THz communication method applicable to the present disclosure. Referring to Fig. 7, THz wireless communication refers to wireless communication using THz waves having a frequency of approximately 0.1 to 10 THz (1 THz = 1012 Hz), and may refer to terahertz (THz) band wireless communication using a very high carrier frequency of 100 GHz or higher. THz waves are located between the RF (Radio Frequency) / millimeter (mm) and infrared bands, and (i) compared to visible light / infrared rays, they penetrate non-metallic / non-polarizable materials well, and compared to RF / millimeter waves, they have a shorter wavelength, thus having high linearity and enabling beam focusing.

[0137] In addition, since the photon energy of THz waves is only a few meV, it has the characteristic of being harmless to the human body. The frequency band expected to be used for THz wireless communication may be the D-band (110 GHz to 170 GHz) or H-band (220 GHz to 325 GHz) bands where propagation loss due to absorption of molecules in the air is small. In addition to 3GPP, standardization discussions for THz wireless communication are being centered around the IEEE 802.15 THz WG (working group), and standard documents issued by the IEEE 802.15 TG (task group) (e.g., TG3d, TG3e) can specify or supplement the contents described in this specification. THz wireless communication can be applied to wireless cognition, sensing, imaging, wireless communication, THz navigation, etc.

[0138] Specifically, referring to Fig. 7, THz wireless communication scenarios can be categorized into macro networks, micro networks, and nanoscale networks. In macro networks, THz wireless communication can be applied to vehicle-to-vehicle (V2V) connections and backhaul / fronthaul connections. In micro networks, THz wireless communication can be applied to fixed point-to-point or multi-point connections such as indoor small cells, wireless connections in data centers, and near-field communication such as kiosk downloading. Table 2 below shows examples of technologies that can be utilized in THz waves.

[0139] Transceivers DeviceAvailable immature: UTC-PD, RTD and SBDModulation and codingLow order modulation techniques (OOK, QPSK), LDPC, Reed Soloman, Hamming, Polar, TurboAntennaOmni and Directional, phased array with low number of antenna elementsBandwidth69 GHz (or 23 GHz) at 300 GHzChannel modelsPartiallyData rate100 GbpsOutdoor deploymentNoFee space lossHighCoverageLowRadio Measurements300 GHz inddorDevice sizeFew micrometers

[0140] FIG. 8 illustrates a THz signal generation method applicable to the present disclosure. FIG. 9 also illustrates a wireless communication transceiver applicable to the present disclosure. Referring to FIGS. 8 and 9, the optical device-based THz wireless communication technology refers to a method of generating and modulating a THz signal using an optical device. The optical device-based THz signal generation technology is a technology that generates an ultra-high-speed optical signal using a laser and an optical modulator, and converts it into a THz signal using an ultra-high-speed photodetector. Compared to a technology that uses only electronic devices, this technology makes it easy to increase the frequency, enables high-power signal generation, and obtains a flat response characteristic over a wide frequency band. For the optical device-based THz signal generation, as illustrated in FIG. 8, a laser diode, a wideband optical modulator, and an ultra-high-speed photodetector are required. In the case of FIG. 8, light signals from two lasers with different wavelengths are combined to generate a THz signal corresponding to the wavelength difference between the lasers. In Fig. 8, an optical coupler refers to a semiconductor device that transmits an electrical signal using optical waves to provide electrical isolation and coupling between circuits or systems, and a uni-travelling carrier photo-detector (UTC-PD) is a type of photodetector that uses electrons as active carriers and reduces the travel time of electrons through bandgap grading. The UTC-PD is capable of photodetection at 150 GHz or higher.In Fig. 9, EDFA (erbium-doped fiber amplifier) ​​represents an erbium-doped fiber amplifier, PD (photo detector) represents a semiconductor device that can convert an optical signal into an electrical signal, OSA represents an optical module (optical sub assembly) that modularizes various optical communication functions (e.g., photoelectric conversion, electro-optical conversion, etc.) into a single component, and DSO represents a digital storage oscilloscope.

[0141] Figure 10 illustrates a transmitter structure applicable to the present disclosure.

[0142] Referring to Figure 10, in order to modulate data into an optical signal, an optical source such as a laser can be passed through an optical wave guide to change the phase of the signal, etc. At this time, data is loaded by changing the electrical characteristics through a microwave contact, etc. Therefore, the optical modulator output is formed as a modulated waveform.

[0143] Data may be provided from a data signal generator. Here, the data may include various user data, configuration information, control information, etc. transmitted through a channel. Furthermore, the data may include data related to AI-based operations, such as information for configuring an AI model, input / output data for tasks of the AI ​​model, etc. To this end, components related to AI functions (e.g., an AI processing unit) may be included in the data signal generator or may be linked to the data signal generator.

[0144] An optical / electronic converter (O / E converter) can generate THz pulses by optical rectification using a nonlinear crystal, photoelectric conversion using a photoconductive antenna, or emission from a bunch of relativistic electrons. The THz pulse generated in the above manner can have a length in the range of femtoseconds to picoseconds. The optical / electronic converter (O / E converter) performs down conversion by utilizing the nonlinearity of the device.

[0145] Considering the THz spectrum usage, it is likely that multiple contiguous GHz bands will be used for THz systems, either fixed or for mobile services. For an outdoor scenario, the available bandwidth can be categorized based on an oxygen attenuation of 10^2 dB / km in the spectrum up to 1 THz. Accordingly, a framework in which the available bandwidth is divided into multiple band chunks can be considered. As an example of this framework, if the THz pulse length for a single carrier is set to 50 ps, ​​the bandwidth (BW) becomes approximately 20 GHz.

[0146] Effective down-conversion from the infrared band to the THz band depends on how to utilize the nonlinearity of the optical / electrical converter (O / E converter). In other words, to down-convert to the desired THz band, it is necessary to design an O / E converter with the most ideal non-linearity for transferring to the THz band. If an O / E converter that is not suitable for the target frequency band is used, errors in the amplitude and phase of the pulse are likely to occur.

[0147] A THz transmission and reception system can be implemented using a single optical-to-electrical converter in a single-carrier system. Depending on the channel environment, optical-to-electrical converters may be required as many as the number of carriers in a multi-carrier system. This phenomenon will be particularly noticeable in a multi-carrier system that utilizes multiple broadbands according to the aforementioned spectrum usage plan. In this regard, a frame structure for the multi-carrier system may be considered. A signal down-frequency converted based on an optical-to-electrical converter may be transmitted in a specific resource region (e.g., a specific frame). The frequency region of the specific resource region may include multiple chunks. Each chunk may be composed of at least one component carrier (CC).

[0148] Transmitting system information (e.g., MIB) in the THz frequency band can be inefficient because the beam width becomes narrower in high-frequency bands, requiring more beam sweeps to cover the entire cell area. This method of transmitting system information is particularly inefficient when there are only a few users within the cell. Accordingly, a system information transmission procedure, such as that illustrated in FIG. 11, may be employed.

[0149] Figure 11 illustrates a system information transmission procedure applicable to the present disclosure. Figure 11 illustrates an example of a procedure for transmitting system information for THz communication. The procedure illustrated in Figure 11 can be combined with various embodiments of the present disclosure described below. For example, the embodiments described below can be performed based on the system information acquired by the procedure illustrated in Figure 11. As another example, information and / or data transmitted in the procedure illustrated in Figure 11 can be generated and / or processed according to the embodiments described below.

[0150] Referring to FIG. 11, in step 1101, the base station (1120) transmits system information of cell #1 through cell #2. That is, the base station (1120) 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, 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 (synchronization signal / physical broadcasting 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.

[0151] In step 1103, UE (1110) acquires synchronization for cell #1. Synchronization can be acquired by detecting a synchronization signal. Typically, synchronization is acquired before receiving system information. However, since 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, UE (1110) can acquire synchronization based on system information. However, unlike FIG. 11, in another example, synchronization acquisition can be performed before step 1101.

[0152] In step 1105, UE (1110) transmits a signal for accessing cell #1. For example, the signal may include a random access preamble. The structure of the signal and the resources (e.g., channels) for transmitting the signal can be identified through system information. Thereafter, in step 1107, UE (1110) and base station (1120) perform an access procedure for cell #1 and communicate. In this step, operations according to various embodiments described below may be performed.

[0153] The procedure described with reference to FIG. 11 may be performed when UE (1101) first connects to cell #1 of base station (1120). Alternatively, a similar procedure may be performed when UE (1101) hands over to cell #1 of base station (1120). However, in the case of handover, system information of cell #1 may be received from a cell of a base station other than cell #2 of base station (1120).

[0154] Communications in the THz band are expected to experience extremely severe path loss, and to overcome this, terminals and base stations must use extremely sharp beams. The use of sharp beams means that terminals and base stations must perform beam control in addition to beamforming, and the number of beams used increases significantly. Consequently, it takes a very long time to align the transmit and receive beams between the base station and terminals. Furthermore, if the beam alignment between the base station and terminals is misaligned due to the movement or movement of the terminals, frequent re-alignment of the beams is required, which can lead to link instability. Accordingly, a beam management procedure, as illustrated in FIG. 12 below, may be used.

[0155] FIG. 12 illustrates a beam management procedure applicable to the present disclosure. FIG. 12 illustrates an example of a procedure for searching and / or selecting beams for THz communication. The procedure illustrated in FIG. 12 may be combined with various embodiments of the present disclosure described below. For example, the embodiments described below may be performed using at least one beam acquired by the procedure illustrated in FIG. 11. As another example, information and / or data transmitted in the procedure illustrated in FIG. 12 may be generated and / or processed according to the embodiments described below. Herein, a beam may be referred to as a 'spatial domain filter', a 'spatial domain transmit filter', a 'spatial domain receive filter', and other terms having equivalent technical meanings thereto.

[0156] Referring to FIG. 12, in step 1201, a base station (1220) configures resources for beam management. Here, the resources may include at least one of time-frequency resources, channels, and spatial resources (e.g., antenna ports). For example, the base station (1220) may utilize a beam search signal (BSS) that is transmitted spatially separated from an existing downlink signal / channel for beam search. Here, the BSS may be transmitted based on a dedicated port for beam search. The dedicated port may be a different port from a port for transmitting an existing downlink signal / channel (e.g., SSB, PDSCH, etc.). BSS is a term defined for convenience of explanation, and the technical concept according to the present embodiment is not limited to the term BSS itself. That is, a signal transmitted based on a dedicated port defined / configured for beam search may be included in the technical concept according to the present embodiment.

[0157] In step 1203, the base station (1201) transmits measurement signals using multiple 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 be transmitted in a multi-beam transmission method that forms multiple 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).

[0158] In step 1205, the UE (1210) transmits a feedback signal to the base station (1220). The feedback signal indicates at least one beam selected by the UE (1210). The UE (1210) may select at least one preferred beam based on the measurement signals received in step 1203. In step 1207, the UE (1210) and the base station (1220) perform communication. At this time, the UE (1210) and the base station (1220) may perform communication using the beam selected in step 1205. If channel reciprocity is established, the transmission beam of the UE (1210) may also be determined through steps 1203 and 1205, and thus, the transmission operation of the UE (1210) may also be performed using the beam selected in step 1205. If channel reciprocity is not established, a procedure including transmitting measurement signals of the UE (1210) and transmitting feedback signals of the base station (1220) may be performed to determine the transmission beam of the UE (1210). In step 1207, operations according to various embodiments described below may be performed.

[0159] Specific embodiments of the present disclosure

[0160] The present disclosure relates to the transmission of a synchronization signal in a wireless communication system, and more particularly, to a technology for a base station to provide signals to terminals within its coverage area for acquiring synchronization with the base station, acquiring minimum information about the base station, etc. More specifically, the present disclosure proposes a technology related to beam sweeping and control of a base station that takes into account the beam sweeping operation of a third device within its coverage area in an environment where a third device other than the base station and the terminal is used for coverage expansion. Hereinafter, the present disclosure explains the proposed technology using SSB as an example of a unit of a signal including a synchronization signal. However, the embodiments described below can also be applied to other signals including a synchronization signal or requiring beam sweeping within coverage, in addition to SSB.

[0161]

[0162] As 5G network deployments increase globally, new applications and use cases requiring wireless communications are expected to proliferate, and research into Beyond-5G (B5G) or 6G is underway. Similar to how massive MIMO (multiple input, multiple output) technology emerged as a promising research topic a decade ago and became a key research topic, new technologies capable of delivering a tenfold performance improvement over 5G will be needed for future applications. In particular, as the frequency used for communications increases, relay communications are being discussed as a candidate technology for coverage enhancement. Specifically, technologies utilizing network controller repeaters (NCRs) and reconfigurable intelligent surfaces (RISs) are being discussed as potential technologies for 6G systems.

[0163] FIG. 13 illustrates an example of an environment in which communication technologies according to one embodiment of the present disclosure are applied. Referring to FIG. 13, terminals (1310) are located within the coverage area of ​​a base station (1320), and RIS (1330), NCR (1340), UAV (1350), UAM (1360), etc. may be deployed to provide communication services to the terminals (1310). RIS (1330) is a device that dynamically shapes and controls a wireless signal in a target-oriented manner using a smart radio surface equipped with thousands of sub-wavelength metamaterial elements. NCR (1340) has two analog antenna arrays, one antenna array facing the base station and the other antenna array facing the terminal. NCR is a device based on the amplify-and-forward (AF) concept that supports beamforming and TDD (time division duplexing) operations to support uplink and downlink.

[0164] Looking at the differences between RIS (1330) and NCR (1340), NCR (1340) can perform frequency modulation / demodulation and amplification operations because it includes an RF module. On the other hand, RIS (1330) cannot perform frequency modulation / demodulation and amplification operations. RIS (1330) has a hardware configuration that only allows phase control by adjusting the switches of elements. Therefore, RIS (1330) has advantages in terms of cost and power consumption compared to NCR (1340), and has a simpler hardware configuration. Both NCR (1340) and RIS (1330) are operated in a way that helps communication services from a relay perspective, and have similar advantages and disadvantages. Therefore, the present disclosure proposes a technology that can be applied to both NCR (1340) and RIS (1330) from a beam management perspective.

[0165] FIG. 14A illustrates an example of the structure of an RIS according to one embodiment of the present disclosure. Referring to FIG. 14A, a terminal (1410) and a base station (1420) perform communication, and an RIS (1430) can assist in signal transmission between the base station (1420) and the terminal (1410).

[0166] The base station (1420) is equipped with multiple antennas and can transmit signals through multiple transmission beams having different directions. In addition, the base station (1420) can establish a connection (e.g., an RRC connection) with the RIS (1430) and control the RIS (1430) through the established connection.

[0167] The RIS (1430) may include a RIS panel (1434) having a plurality of elements, and a RIS controller (1432) controlling the RIS panel (1434). The RIS (1430) may be positioned to improve communication performance between the base station (1420) and the terminal (1410). For example, since the wireless environment cannot be changed while the terminal (1410) is fixed, the radio wave intensity of SSB from the base station (1420) to the terminal (1410) is limited by the wireless environment. At this time, by changing the reflection angle of the RIS (1430), a wireless environment suitable for the terminal (1410) can be formed, thereby overcoming the limitations caused by the aforementioned wireless environment and providing an environment optimized for wireless communication transmission.

[0168] The RIS controller (1432) can establish a connection with the base station (1420) and transmit resource information of the RIS (1430) to the base station (1420) through the established connection. The RIS controller (1432) can receive a control signal from the base station (1420) and set the reflection angle of the RIS panel (1434) based on the control signal. The control signal can include information requesting setting and / or changing the reflection angle of the RIS. The RIS panel (1434) can reflect signals transmitted from the base station (1420). At this time, the signals can be reflected according to the reflection angle set by the RIS controller (1432).

[0169] FIG. 14B illustrates an example of the structure of an NCR according to one embodiment of the present disclosure. FIG. 14B illustrates a topology in which an NCR (1440) performs transmission and reception between a base station (1420) and a terminal (1410). The NCR (1440) of FIG. 14B is a type of wireless device, and includes the structure illustrated in FIG. 2 and may include the functional components illustrated in FIG. 14B. Referring to FIG. 14B, the NCR (1440) may include an NCR-MT (1442) and an NCR-Fwd (1444). The NCR (1440) may be connected to the base station (1420) and the terminal (1410).

[0170] NCR-Fwd (1444) can receive a signal transmitted from a base station (1420) at the RF end and forward it to a terminal (1410), and can receive a signal transmitted from a terminal (1410) at the RF end and forward it to the base station (1420). NCR-Fwd (1444) only transfers a signal between the base station (1420) and the terminal (1410), and may not have a function of generating a signal / channel on its own and transmitting it to the base station (1420) / terminal (1410), or receiving and detecting a signal / channel from the base station (1420) / terminal (1410). In order to forward the received signal, NCR-Fwd (1444) can adjust the transmission / reception beam direction, DL / UL direction, ON / OFF status, Tx power, etc. at the RF end. However, the operation of this NCR-Fwd (1444) cannot be performed by the judgment of the NCR (1440) itself, and can be controlled by the base station (1420).

[0171] The NCR-MT (1442) may include an RF layer and L1, L2, and / or L3. For example, the NCR-MT (1442) may consist of only an RF layer and L1 or L1 / L2, or the NCR-MT (1442) may consist of an RF layer and L1 / L2 / L3. The NCR-MT (1442) may detect / receive a signal / channel transmitted from the base station (1420), and the NCR-MT (1442) may generate and transmit a signal / channel transmitted to the base station (1420). In addition, the NCR-MT (1442) may receive information (e.g., side control information) necessary to control the operation of the NCR-Fwd (1444) from the base station (1420). The NCR-MT (1442) may not perform transmission and reception with the terminal (1410). The functions of NCR-MT (1442) and NCR-Fwd (1444) are summarized in [Table 3] below.

[0172] Component Description NCR-MT NCR-MT is defined as a function entity to communicate with a gNB via Control link (C-link) to enable the information exchanges (e.g. side control information). The C-link is based on the NR Uu interface. Note: Side control information is at least for the control of NCR-Fwd NCR-Fwd is defined as a function entity that performs UL / DL RF signal amplification and forwarding between the gNB and the UE via the backhaul link and the access link. The operation of the NCR-Fwd is controlled according to the side control information received from the gNB. (The NCR-Fwd is defined as a function entity to perform the amplify-and-forwarding of UL / DL RF signal between gNB and UE via backhaul link and access link. The behavior of the NCR-Fwd will be controlled according to the received side control information from gNB.)

[0173]

[0174] Typically, NCRs and / or RISs are fixedly deployed, so both fixed beams and adaptive beams can be considered. In situations where NCRs and / or RISs are deployed, beam sweeping may be performed to transmit SSBs within the coverage area, as follows:

[0175] Figure 15 illustrates an example of beam sweeping for transmitting SSB in an environment where an NCR is deployed. Referring to Figure 15, when a base station (1520) transmits SSB, the number of SSB transmissions may increase due to the deployment of an NCR (1540). Specifically, for beam sweeping of the NCR (1540), the base station (1520) is required to repeatedly transmit beams toward the NCR (1540) as many times as the number of beams formed by the NCR (1540).

[0176] Thus, the presence of NCRs increases the number of beams (hereinafter referred to as "SSB beams") used to transmit SSB. Furthermore, as the number of NCRs increases, the total number of SSB beams increases, which may increase overhead. Therefore, it may be desirable to limit the maximum number of SSB and CSI-RS beams.

[0177] Fig. 16a illustrates an example of beam operation for transmitting SSBs in an environment where an NCR is deployed. Referring to Fig. 16a, a base station (1620) transmits M SSB beams, and repeatedly transmits one beam (e.g., beam B0) directed toward an NCR (1640) among the M SSB beams N times. Accordingly, a backhaul device (1640a) of the NCR (1640) receives an SSB through beam b0 corresponding to beam B0, and an access device (1640b) of the NCR (1640) transmits an SSB through N beams (e.g., t0, t M Inland t M+N-2 ) transmits SSB. That is, the base station (1620) transmits M beams having different directions, and then transmits N-1 additional fixed beams having the same direction, and can steer the beams in different directions by controlling the NCR (1640).

[0178] At this time, depending on the number of deployed NCRs, the number of SSB transmission opportunities for completing beam sweeping in the coverage of the base station (1620) and the coverage of at least one NCR including NCR (1640) may vary. Fig. 16b illustrates an example of the change in the number of required SSB transmission opportunities depending on the number of NCRs. Referring to Fig. 16b, it is confirmed that as the number of NCRs increases, the overhead due to SSB transmission continuously increases.

[0179] Furthermore, in this case, a situation may arise where beams with the same beam ID (e.g., N-1 additional beams) are transmitted at different times. This may lead to a problem called temporal ambiguity. That is, a terminal receiving SSBs cannot determine in which time interval the received SSB was transmitted by the base station.

[0180] As described above, even though both the NCR and / or RIS are installed in fixed locations, the beam sweeping of the base station and the beam sweeping of the NCR and / or RIS can be performed at different intervals in time. That is, the beam sweeping of the base station and the beam sweeping of the NCR and / or RIS can be performed in a series manner, that is, sequentially.

[0181] In the present disclosure, the NCR and / or RIS assist communication between the base station and the terminal by amplifying, reflecting, or regenerating signals between the base station and the terminal. Therefore, hereinafter, in the present disclosure, the NCR and / or RIS may be referred to as an 'assistance node', an 'extension node', a 'side node', a 'relay node', an 'assistance device', a 'side device', an 'extension device', a 'relay device', or other terms having equivalent technical meanings thereto.

[0182] As described above, when the beam sweeping of the base station and the beam sweeping of the auxiliary node are performed sequentially, the time required to transmit SSBs over the entire coverage of the base station and the auxiliary node may be greater than the sum of the beam sweeping time of the base station and the beam sweeping time of the auxiliary node. Accordingly, the present disclosure proposes a technique for performing the beam sweeping time of the base station and the beam sweeping of the auxiliary node in parallel, i.e., simultaneously. Here, performing simultaneously means that the time intervals during which the two (2) beam sweeping operations are performed overlap at least partially.

[0183] In order to perform beam sweeping time of a base station and beam sweeping of an auxiliary node in parallel, it is required that the base station simultaneously form a beam directed within its own coverage and a beam directed toward the auxiliary node. For this purpose, multi-beam forming can be performed. In general, multi-beam can be implemented according to a hybrid beamforming method or a digital beamforming method. FIG. 17A and FIG. 17B illustrate examples of a structure for forming a multi-beam according to an embodiment of the present disclosure. FIG. 17A illustrates a structure for forming a multi-beam based on a digital method, and FIG. 17B illustrates a structure for forming a multi-beam based on a hybrid method.

[0184] Referring to FIG. 17a, a digital signal generated in a digital baseband processing block (1702) is converted into analog signals by RF chains (1704a) and transmitted through an antenna array (1710). At this time, digital beamforming is performed in the digital baseband processing block (1702), and accordingly, signals radiated from the antenna array (1710) form a plurality of beams.

[0185] Referring to FIG. 17b, a digital signal generated in a digital baseband processing block (1702) is converted into analog signals by RF chains (1704b), and each analog signal is split into multiple signals by splitters (1706). The split signals are subjected to analog beamforming by an analog phase shift block (1708) and transmitted through an antenna array (1710). At this time, digital beamforming is performed in the digital baseband processing block (1702), and analog beamforming is performed by the analog phase shift block (1708), and accordingly, signals radiated from the antenna array (1710) form multiple beams.

[0186]

[0187] Multi-beam forming of multiple signals using multiple chains

[0188] Typically, a single RF chain transmits a single signal. Therefore, when multiple RF chains are used, transmitting different signals from each RF chain can be more efficient from a beam management perspective. Therefore, an example of transmitting different signals from RF chains capable of simultaneously forming different beams is as follows.

[0189] Figures 18a and 18b illustrate examples of parallel beam sweeping of a base station and an auxiliary node, in which different signals are transmitted in chains, according to one embodiment of the present disclosure. Referring to Figure 18a, a base station (1820) performs beam sweeping using adaptive beams. Simultaneously, the base station (1820) repeatedly transmits a signal to an auxiliary node (1850) using a fixed beam, and the auxiliary node (1850) performs beam sweeping by transmitting or reflecting the signal. That is, if the beam sweeping of the base station (1820) and the beam sweeping of the auxiliary node (1850) are performed simultaneously, i.e., in parallel, the increase in consumed time as the number of auxiliary nodes increases will be reduced.

[0190] Specifically, referring to FIG. 18b, during M transmission opportunities, the base station (1820) transmits beams B0 to B M-1 Perform beam sweeping using beam B0 and use beam B0 as a fixed beam. Accordingly, the auxiliary node (1850) uses beam C0 to C during beam sweeping of the base station (1820). M-1 Beam sweeping can be performed using . At this time, there is a mapping relationship between the beam of the base station (1820) and the index of the SSB. Accordingly, the SSB transmitted through beam B0 is SSB#0. Therefore, the beam C0 to C of the auxiliary node (1850) M-1 All beams transmitted through carry SSB#0.

[0191]

[0192] Multi-beam forming of the same signal using multiple chains

[0193] By performing parallel beam sweeping as shown in FIGS. 18a and 18b, the overall beam sweeping time can be reduced. However, even when applying parallel beam sweeping, problems may still arise due to beams with the same ID being repeatedly transmitted, and problems may still arise due to the number of SSB beams increasing together with the number of NCRs. Therefore, considering that there is no restriction that multiple RF chains must necessarily transmit different signals, it is possible to form multi-beams to transmit the same signal through multiple RF chains.

[0194] Figures 19a and 19b illustrate examples of parallel beam sweeping of a base station and an auxiliary node, wherein identical signals are transmitted in chains, according to one embodiment of the present disclosure. Referring to Figure 19a, a base station (1920) performs beam sweeping using adaptive beams, and simultaneously repeatedly transmits signals to an auxiliary node (1950) using a fixed beam. The auxiliary node (1950) then performs beam sweeping by transmitting or reflecting signals received via the fixed beam. At this time, the same SSB is transmitted via the adaptive beam and the fixed beam at each transmission opportunity.

[0195] Accordingly, referring to FIG. 19b, during M transmission opportunities, the base station (1920) transmits beams B0 to B M-1 Perform beam sweeping using beam B0 and use beam B0 as a fixed beam. Accordingly, the auxiliary node (1950) uses beam C0 to C during beam sweeping of the base station (1920). M-1Beam sweeping can be performed using beam B0. At this time, SSB#0 to SSB#M-1 can be transmitted during multiple transmission opportunities through beam B0, which is a fixed beam. Accordingly, beam C0 to C of the auxiliary node (1950) M-1 The beams transmitted through can carry SSBs of different indices, for example, SSB#0 to SSB#M-1.

[0196] By performing parallel beam sweeping, as shown in FIGS. 19a and 19b, the overall beam sweeping time can be reduced, and furthermore, SSBs of different indices can be transmitted by the auxiliary node. Here, multiple beams carrying the same signal transmitted from the base station can be understood as follows.

[0197] Wide beams and narrow beams are distinguished by their relative beam widths. In other words, the distinction between wide and narrow beams is not defined by the absolute beam width or the shape of the beam, but by the difference in relative beam widths. Therefore, even if a null exists in some area of ​​the beam, as in the multi-beam of Fig. 19a, if it carries the same information and / or signal, the multi-beam can be understood as a single wide beam.

[0198] FIG. 20 illustrates examples of wide beams of different shapes according to one embodiment of the present disclosure. Referring to FIG. 20, as wide beam shapes, a wide beam (2004) that does not include a null region and a wide beam (2004) that includes a null region are exemplified. The wide beam (2004) that includes a null region is similar to a shape in which a single beam is split due to a null region, and thus may be referred to as a split beam or another term having an equivalent technical meaning.

[0199] FIGS. 21A and 21B illustrate the number of beams required for beam sweeping when applying a multi-beam method using multiple chains according to one embodiment of the present disclosure.

[0200] Referring to Fig. 21a, when the beam width of one wide beam (hereinafter referred to as 'SSB beam') used for transmitting SSB is set to 20°, the beam width of the auxiliary node is set to 10°, and one auxiliary node is deployed, the maximum number of SSB beams for performing beam sweeping in a 180° range of coverage can be calculated as follows. If the proposed technique is not applied, the required number of beams is 26. On the other hand, according to the proposed technique, if the SSB beam of the base station is allocated to the fixed beam part with 10° and the adaptive beam part with 10°, the required number of SSBs is 18.

[0201] Referring to Fig. 21b, in a similar manner, when the beam width of the SSB beam is set to 30°, the beam width of the auxiliary node is set to 10°, and two auxiliary nodes are deployed, the maximum number of SSB beams for performing beam sweeping in a 180° range of coverage can be calculated as follows. If the proposed technique is not applied, the required number of beams is 40. On the other hand, according to the proposed technique, when the SSB beam of the base station is allocated to each of the two fixed beam parts with 10° and the adaptive beam part with 10°, the required number of SSBs is 18.

[0202] Additionally, the number of beams required in various situations is compared before and after applying the proposed technology as follows.

[0203] When one auxiliary node is deployed and the base station beam width is 12˚ and the auxiliary node beam width is 6˚, the number of beams to cover the 180˚ area of ​​the base station is 15 and the number of beams to cover the 180˚ area of ​​the auxiliary node is 30, so if the proposed technology is not applied, the total number of beams required is 15+30-1=44. On the other hand, if the proposed technology is applied, when 6˚ is allocated to the fixed beam part of the base station and 6˚ is allocated to the adaptive beam part, the number of beams to cover the 180˚ area of ​​the base station is 30 and the number of beams to cover the 180˚ area of ​​the auxiliary node is 30, so the total number of beams required is 30.

[0204] When two auxiliary nodes are deployed and the base station beam width is 12˚ and the auxiliary nodes beam width is 4˚, the number of beams to cover the 180˚ area of ​​the base station is 15, the number of beams to cover the 180˚ area of ​​the first auxiliary node is 45, and the number of beams to cover the 180˚ area of ​​the second auxiliary node is 45, so if the proposed technology is not applied, the total number of beams required is 15+-45+45-1=103. On the other hand, if the proposed technology is applied, when 4˚ is allocated to the fixed beam part of the base station and 4˚ is allocated to the adaptive beam part, the number of beams to cover the 180˚ area of ​​the base station is 45, and the number of beams to cover the 180˚ area of ​​each auxiliary node is 45, so the total number of beams required is 45.

[0205] When one auxiliary node is deployed and the base station beam width is 12˚ and the auxiliary node beam width is 12˚, the number of beams to cover the 180˚ area of ​​the base station is 15, and the number of beams to cover the 180˚ area of ​​the auxiliary node is 15, so if the proposed technology is not applied, the total number of beams required is 15+15-1=29. On the other hand, if the proposed technology is applied, when 6˚ is allocated to the fixed beam part of the base station and 6˚ is allocated to the adaptive beam part, the number of beams to cover the 180˚ area of ​​the base station is 30, and the number of beams to cover the 180˚ area of ​​the auxiliary node is 15, so the total number of beams required is 30. Here, if the 180˚ range is divided into two 90˚ ranges and a split beam is used in the first range and a wide beam is used in the second range, the number of beams to cover the first range of the base station is 15, the number of beams to cover the second range is 8, and the number of beams to cover the 180˚ area of ​​the auxiliary node is 15, so the total number of beams required is 23.

[0206] When one auxiliary node is deployed and the base station beam width is 6˚ and the auxiliary node beam width is 6˚, the number of beams to cover the 180˚ area of ​​the base station is 30, and the number of beams to cover the 180˚ area of ​​the auxiliary node is 30, so if the proposed technology is not applied, the total number of beams required is 30+30-1=59. On the other hand, if the proposed technology is applied, when the base station allocates 1˚ to the fixed beam part and 5˚ to the adaptive beam part, the number of beams to cover the 180˚ area of ​​the base station is 36, and the number of beams to cover the 180˚ area of ​​the auxiliary node is 30, so the total number of beams required is 36. Here, if the 180˚ range is divided into a first range of 150˚ and a second range of 30˚, and a split beam is used in the first range and a wide beam is used in the second range, the number of beams to cover the first range of the base station is 30, the number of beams to cover the second range is 5, and the number of beams to cover the 180˚ area of ​​the auxiliary node is 30, so the total number of beams required is 35.

[0207] Multi-beam formation using a single chain

[0208] In the embodiments described above, multiple beams are formed using multiple RF chains. This allows the base station to perform beam sweeping while transmitting signals to the auxiliary node using both fixed and adaptive beams. At this time, by controlling the signals input to each RF chain equally or differently, the indices of the SSBs transmitted through beam sweeping by the auxiliary node can be identical or different.

[0209] In another embodiment, it is possible to form a split beam using a single RF chain. In other words, it is possible to form a single beam using a single RF chain, and to split the beam shape by adjusting the phase distribution of the beam, i.e., to form a split beam. In this case, the observed beam sweeping procedure may be similar to the embodiment described with reference to FIGS. 19A and 19B. However, the difference is that, rather than transmitting the same signal through multiple RF chains, a single RF chain is used, but a null region is intentionally formed in the beam.

[0210]

[0211] Figures 22a and 22b illustrate examples of beam cancellation phenomena according to the control of two antenna elements. Figure 22a illustrates a case where two antenna elements (2250-1 and 2250-2) are set to the same phases (e.g., 0 degrees), and Figure 22b illustrates a case where two antenna elements (2250-1 and 2250-2) are set to opposite phases (e.g., 0 degrees and 180 degrees). Referring to Figure 22a, when the antenna elements (2250-1 and 2250-2) are set to the same phases, an equi-phase front is formed, and a beam is generated in the direction of the equi-phase front. Referring to Figure 22b, when the antenna elements (2250-1 and 2250-2) are set to opposite phases, the beams are canceled in the direction of the equi-phase front. Accordingly, by the law of conservation of energy, two beams are formed that are symmetrical with respect to the intended direction in which the energy of the canceled beam is equal to that of the canceled beam.

[0212] When a larger number of antenna elements are used, the characteristics of the beams formed may vary depending on the pattern of phase values ​​set to the antenna elements. Examples of beam patterns according to the pattern of phase values ​​are as shown in FIG. 23 below. FIG. 23 illustrates examples of various beam patterns according to the control of a plurality of antenna elements. Referring to FIG. 23, the angle between two beams is large in the order of the first pattern (2310), the second pattern (2320), the third pattern (2330), and the fourth pattern (2340), and the beam width of each beam is large.

[0213] FIG. 24 illustrates an example of beamforming using a non-uniform phase front in an antenna array according to an embodiment of the present disclosure. Referring to FIG. 24, an antenna array (2460) includes a plurality of antenna elements (2450). According to an embodiment, each of the plurality of antenna elements (2450) may include at least one of a reflective patch for reflecting a signal, at least one line to which a control signal for setting a phase shift value is applied, and a switch controlled according to the control signal. The antenna array (2460) according to various embodiments may generate a non-uniform phase front rather than an equal phase front according to the phase pattern of the antenna elements (2450), and may form at least one beam based on the non-uniform phase front. Due to the non-uniform phase front, a beam scattering phenomenon may occur, and a plurality of beams may be formed. The phenomenon of forming a plurality of beams may be explained as follows.

[0214] For example, when scattered beams are formed in two directions, the weighted sum of phasing vectors for the two directions can be expressed as follows [Mathematical Formula 1].

[0215]

[0216] In [Equation 1], is the weighted sum of phase vectors, is the phase vector for the first direction, denotes the phase vector for the second direction.

[0217] At this time, the complex weight sum set to the nth antenna element is as follows [Mathematical Formula 2].

[0218]

[0219] In [Equation 2], is the complex weighted sum set to the nth antenna element, is the phase constant for the first direction, denotes the phase constant for the second direction.

[0220] The amplitude term and phase term of the complex weight sum set to the nth antenna element can be expressed as in [Mathematical Formula 3] below.

[0221]

[0222] In [Equation 3], is the size value set for the nth antenna element, is the phase constant for the first direction, is the phase constant for the second direction, means the phase value set to the nth antenna element.

[0223] Here, the magnitude term is determined based on the coding sequence principle to implement a non-uniform phase front, and may be referred to as a 'bit term'. A negative term may be expressed as a coding sequence of 0, i.e., a phase shift of 0 degrees, and a positive term may be expressed as a coding sequence of 1, i.e., a phase shift of 180 degrees. The coding sequences set according to the negative and positive terms are added to the phase term, thereby implementing a non-uniform phase front. Due to the non-uniform phase front, interference (e.g., cancellation and reinforcement) may occur between beams, and consequently, multi-beams may be generated.

[0224] The operation of forming the two beams described above can be generalized as follows. A scattered beam pattern including k beams is formed, and the complex weighted sum for the nth antenna element of the antenna array can be expressed as follows [Mathematical Formula 4].

[0225]

[0226] In [Equation 4], is the complex weighted sum set to the nth antenna element, , , … , is the phase constant of each of the k beams, is half the wavelength of the signal, is the index of the antenna element, refers to the wavelength of the signal.

[0227] cast as, cast If substituted, the weighted sum for each antenna element can be organized as shown in [Mathematical Formula 5] below.

[0228]

[0229] In [Equation 5], is the complex weighted sum set to the nth antenna element, , , … , is the phase constant of each of the k beams, represents the index of the antenna element.

[0230] If we divide the complex weight sum set to the nth antenna element into an amplitude term and a phase term, the amplitude term and the phase term are as follows [Mathematical Formula 6].

[0231]

[0232] In [Equation 6], is the size value set for the nth antenna element, is the complex weighted sum set to the nth antenna element, means the phase value set to the nth antenna element.

[0233] When [Equation 6] is rearranged for the case of two beams, i.e., k=2, the following [Equation 7] and [Equation 8] are obtained.

[0234]

[0235] In [Equation 6], is the size value set for the nth antenna element, and denotes the phase constant for each of the two beams.

[0236]

[0237] In [Equation 8], is the phase value set to the nth antenna element, and denotes the phase constant for each of the two beams.

[0238] The weighted sum of the phase vectors determined according to [Mathematical Formula 8] is applied to each antenna element together with a code sequence item (e.g., 0 or 1). The code sequence item is determined based on a magnitude value determined as in [Mathematical Formula 7]. For example, the code sequence item can be determined as 0 if the magnitude value is positive, and as 1 if the magnitude value is negative. That is, the final phase vector, i.e., the multi-beam phase vector, can be determined by adding the weighted sum of the phase vectors and the code sequence. Here, beam scattering occurs by the addition of the code sequence. Therefore, the code sequence may be referred to as a code vector, a scattering code, a scattering sequence, a scattering factor, a scattering vector, or other terms having an equivalent technical meaning thereto. Additionally, the weighted sum of phase vectors may be referred to as a 'weighted summed phase vector', a 'weighted summed phase pattern', a 'combined phase pattern' or other terms having equivalent technical meaning.

[0239] FIGS. 25A to 25D illustrate examples of configurations of an antenna array for multi-beam beamforming according to one embodiment of the present disclosure. FIG. 25A illustrates a phase matrix for a first beam directed in a first direction at an azimuth angle of 30 degrees and an elevation angle of 40.125 degrees, and FIG. 25B illustrates a phase matrix for a second beam directed in a second direction at an azimuth angle of 0 degrees and an elevation angle of 0 degrees.

[0240] The phase constants used in the phase matrix for the first beam oriented at an azimuth angle of 30 degrees and an elevation angle of 40.125 degrees, as in Fig. 25a, can be determined as in [Mathematical Expressions 9] and [Mathematical Expressions 10] below.

[0241]

[0242] In [Equation 9], denotes the horizontal phase constant for the first beam.

[0243]

[0244] In [Equation 10], denotes the vertical phase constant for the first beam.

[0245] A phase matrix can be determined by multiplying the phase constants determined as in [Mathematical Formula 9] and [Mathematical Formula 10] by the port index value as in [Mathematical Formula 11] below.

[0246]

[0247] In [Equation 11], is the phase value applied to the antenna element of the nth row and mth column to form the first beam, is the horizontal phase constant for the first beam, denotes the vertical phase constant for the first beam.

[0248] Similarly, the phase constants used in the phase matrix for the first beam oriented at azimuth 0 degrees and elevation 0 degrees, such as in Fig. 25b, can be determined as in [Mathematical Expressions 12] and [Mathematical Expressions 13] below.

[0249]

[0250] In [Equation 12], denotes the horizontal phase constant for the second beam.

[0251]

[0252] In [Equation 13], denotes the vertical phase constant for the second beam.

[0253] A phase matrix can be determined by multiplying the phase constants determined as in [Mathematical Formula 12] and [Mathematical Formula 13] by the port index value as in [Mathematical Formula 14].

[0254]

[0255] In [Equation 14], is the phase value applied to the antenna element of the nth row and mth column to form the second beam, is the horizontal phase constant for the second beam, denotes the vertical phase constant for the second beam.

[0256] When performing single-beam beamforming, a phase vector such as that shown in FIG. 25a or FIG. 25b may be used. According to one embodiment, when performing multi-beam beamforming including a first beam and a second beam, magnitude values ​​(2532) and phase values ​​(2534) may be determined as shown in FIG. 25c. Here, the magnitude values ​​(2532) and phase values ​​(2534) may be determined as shown in the following [Mathematical Formula 15].

[0257]

[0258] In [Equation 15], is the size value corresponding to the antenna element of the nth row and mth column for multi-beam beamforming, is the phase value corresponding to the antenna element of the nth row and mth column for multi-beam beamforming, is the phase value applied to the antenna element of the nth row and mth column to form the first beam, means the phase value applied to the antenna element of the nth row and mth column to form the second beam.

[0259] A code sequence (2542) is determined based on the size values ​​(2532) determined as in [Mathematical Formula 15]. The code sequence (2542) has a length equal to the number of size values ​​(2532), and each element has a value of 0 or 180. In Fig. 25d, a code sequence value of 1 is applied to the shaded antenna elements, and accordingly, 180 degrees is added to the phase value. Accordingly, a multi-beam phase pattern (2546) applied to the antenna elements is determined, and a multi-beam can be formed according to the multi-beam phase pattern (2546).

[0260]

[0261] Figures 26a to 26c illustrate graphs showing the performance of a multi-beam forming technique according to an embodiment of the present disclosure. Figures 26a to 26c illustrate the results of forming multi-beams in two directions, specifically, {0 degrees, -40 degrees}, {10 degrees, -40 degrees}, {26 degrees, -40 degrees}, and {30 degrees, -40 degrees}, under a single polarization condition, when a technique for grouping antenna elements by direction (hereinafter referred to as the "antenna element splitting technique") is used and when the proposed technique is used. Referring to Figure 26a, in the case of the antenna element splitting technique, interference exists between beams, and thus, loss and direction error exist. On the other hand, referring to Figure 26b, in the case of the proposed technique, interference between beams hardly occurs, and thus, loss and direction error are not observed. Figure 26c shows beams in the {0 degree, -40 degree} direction formed according to the formed antenna element splitting technique and beams in the {0 degree, -40 degree} direction formed according to the proposed technique. Referring to Figure 26c, it is confirmed that interference between beams is significantly reduced when the proposed technique is used.

[0262] FIGS. 27A and 27B illustrate three-dimensional views of three beams formed using a multi-beam forming technique according to an embodiment of the present disclosure. Referring to FIG. 27, it can be confirmed that the proposed technique can generate multiple beams in any direction without the limitation of symmetrical reflection beams. That is, each of the three beams (2701 to 2703) has independence and degrees of freedom. Similarly, referring to FIGS. 28A and 28B, four beams (2801 to 2804) are formed without limitations such as symmetry. Similarly, referring to FIGS. 29A and 29B, five beams (2901 to 2905) can be formed with independence and degrees of freedom without limitations such as symmetry.

[0263] In an environment where a metasurface and / or an RIS is used, a base station and a RIS controller can control beams of a panel including a metasurface. As described above, as the size of the metasurface increases and the number of unit cells increases, the beamwidths of the reflected beams may decrease, which may lead to an exponential increase in the number of beams that must be controlled by the base station or RIS controller. Therefore, multi-beam reflection is required to reduce the increased beam search time. The three existing technologies introduced above have many shortcomings, such as loss and direction error due to beam interference problems, and are polarization-dependent, which limits the number of beams or has a symmetric property that does not allow independent control of each beam. On the other hand, the proposed technique has almost no beam interference problems and is not dependent on the polarization of the incident beam. Therefore, the proposed technique has no limit on the number of beams and can support independent control of each beam.

[0264] As described above, by utilizing the multi-beam forming method using a single chain, SSB beam sweeping can be performed similarly to the multi-beam forming method of the same signal using multiple chains described with reference to FIGS. 19A and 19B. When applying the multi-beam forming method using a single chain, beam sweeping can be performed with the minimum number of beams if the base station and auxiliary nodes operate the same number of beams.

[0265] FIG. 30 illustrates the number of beams required for beam sweeping when applying a multi-beam scheme using a single chain according to an embodiment of the present disclosure. Referring to FIG. 30, when the beam width of an SSB beam is set to 30°, the beam width of an auxiliary node is set to 10°, and two auxiliary nodes are deployed, the maximum number of SSB beams for performing beam sweeping in a 180° range of coverage can be calculated as follows. When the proposed technique is not applied, the required number of beams is 40. On the other hand, according to the proposed technique, when the SSB beam of the base station is allocated to each of two fixed beam parts with 10° and to the adaptive beam part with 10°, the required number of SSBs is 18.

[0266]

[0267] FIG. 31 illustrates an example of a procedure for transmitting a synchronization signal according to one embodiment of the present disclosure. FIG. 31 illustrates a method performed by a base station.

[0268] Referring to FIG. 31, in step S3101, the base station generates a synchronization signal. The base station generates a synchronization signal that is broadcast to terminals within the coverage area or to terminals within the coverage area of ​​an auxiliary node deployed within the coverage area. For example, the base station may generate at least one sequence determined based on a cell identifier (ID) and generate a synchronization signal based on the sequence. At this time, although not illustrated in FIG. 31, the base station may also generate system information.

[0269] In step S3103, the base station determines resources for the synchronization signal. Resources for the synchronization signal can be determined on the time axis and frequency axis. Resources for the synchronization signal can be determined based on signal settings (e.g., subcarrier spacing, frequency, etc.) at the physical layer. Specifically, the base station can determine the transmission period or cycle of the synchronization signal, the number of transmission opportunities included in one period or cycle, the interval between transmission opportunities, etc.

[0270] In step S3105, the base station determines the transmission directions and order of the synchronization signals. In other words, the base station performs scheduling for the synchronization signals. Here, the base station can determine the transmission directions and order of the synchronization signals based on at least one of the resources determined in step S3103, the number of auxiliary node(s) arranged within the coverage of the base station, the beam width of the base station, and the coverage and beam width of each auxiliary node(s). At this time, the base station can determine the transmission directions and order of the synchronization signals so that beam sweeping for the entire coverage is completed during at least one transmission period or at least one cycle of one synchronization signal.

[0271] In step S3107, the base station transmits synchronization signals. The base station can transmit the synchronization signals according to the directions and order determined in step S2705 through the resources determined in step S2703. At this time, according to various embodiments of the present disclosure, at least one of the synchronization signals is transmitted in multiple directions via a multi-beam in at least one transmission opportunity. The multi-beam may be formed based on one of a multi-beam forming method using a single chain and a multi-beam forming method using multiple chains. Here, at least one of the multiple directions may be directed toward at least one auxiliary node, and at least one of the remaining directions may be directed toward a terminal within the coverage of the base station. At this time, according to various embodiments, the beamwidths of the fixed beam and the swept beam directed toward the auxiliary node may be different or the same. Accordingly, transmission of the synchronization signal to at least one auxiliary node using the fixed beam may be performed simultaneously with transmission of the synchronization signal to a terminal within the coverage.

[0272] In the embodiment described with reference to FIG. 31, synchronization signals can be transmitted using multiple beams. Here, in the case of a multi-beam forming method using a single chain, the base station can form the multi-beams as follows.

[0273] The base station determines desired directions. Here, the desired directions include two or more directions. The two or more directions may be independent of each other. For example, the two or more directions may be adjacent directions for beam sweeping or directions toward specific devices. According to one embodiment, for transmitting a synchronization signal, the base station may select a plurality of consecutive directions as desired directions. The desired directions may include directions for an adaptive beam and a direction of at least one fixed beam. The direction of at least one fixed beam may include a direction toward an auxiliary node.

[0274] Thereafter, the base station determines a phase pattern for each direction. The phase pattern refers to a set of phase values ​​for the reflection of a signal generated from antenna elements included in the antenna array. In other words, the base station determines the phase values ​​to be applied to the antenna elements included in the antenna array. In other words, the base station can calculate the analog phase required for the antenna elements for beamforming in each direction. For example, phase patterns for each direction may be predefined, and the base station can check the phase patterns corresponding to each direction selected from a predefined mapping table. As another example, a phase pattern calculation formula based on angle values ​​indicating a direction may be defined, and the base station can determine the phase patterns using the calculation formula.

[0275] Thereafter, the base station determines a combined phase pattern. The combined phase pattern is a result of weighted summation of phase patterns for the intended directions and includes the same number of phase values ​​as the phase patterns for each direction. Specifically, the base station can combine the phase patterns by checking the weights for each direction and summing the products of the weights for each direction and the phase values ​​for each beam for each antenna element. In this case, if the weights for the directions are the same, the weighted summation can be understood as averaging. Next, the base station determines a scattering vector. The scattering vector can be understood as a phase sequence applied to the antenna array to induce beam scattering. To this end, the base station can determine a magnitude vector based on the phase patterns for the intended directions and determine the scattering vector based on the magnitude values ​​included in the magnitude vector. In one embodiment, the base station can determine the scattering vector based on the result of a cosine operation on the weighted sum of the phase patterns for each direction. For example, some of the weights for the weighted sum may be negative. Additionally, the sum of the absolute values ​​of the weights for the weighted sum may be 1. For example, if two directions are intended, the weights may be 1 / 2 and -1 / 2. In this case, the value of each element included in the scattering vector may be determined depending on whether the result of the cosine operation is negative or positive. Here, each element of the scattering vector may have a value of 0 or 180 degrees.

[0276] A base station forms scattering beams based on a weighted sum phase pattern and a scattering vector. Specifically, the base station can transmit a source signal in multiple directions by applying the weighted sum phase pattern and the scattering vector to antenna elements. In other words, the base station determines a phase pattern for multi-beam beamforming applied to an antenna array by summing the weighted sum phase pattern and the scattering vector for each antenna element, and controls the antenna elements by outputting a control signal corresponding to the phase pattern for multi-beam beamforming. Accordingly, a beam scattering phenomenon may occur in the antenna array.

[0277]

[0278] FIG. 32 illustrates an example of a procedure for receiving a synchronization signal according to one embodiment of the present disclosure. FIG. 32 illustrates a method performed by a terminal.

[0279] Referring to Figure 32, at step S3201, the terminal determines resources for the synchronization signal. For example, the terminal may determine the frequency location at which the synchronization signal can be transmitted based on a raster. Accordingly, although not illustrated in Figure 32, the terminal may tune the reception range of the receiver and attempt to receive the synchronization signal.

[0280] In step S3203, the terminal receives a synchronization signal. The terminal may receive a synchronization signal transmitted by the base station. The synchronization signal may be received via a direct channel between the base station and the terminal, or via an auxiliary node. The synchronization signal received by the terminal may include at least one of the synchronization signals transmitted in multiple directions via multi-beams.

[0281] In step S3205, the terminal performs a connection procedure. That is, the terminal can perform a random access procedure. Specifically, the terminal can acquire synchronization with the base station using the received synchronization signal, receive system information, transmit a RACH preamble, and receive a message including a random access response (RAR). Through this, the terminal can connect to the base station and perform communication. At this time, depending on the terminal's location, the terminal can connect directly to the base station or through an auxiliary node.

[0282]

[0283] FIG. 33 illustrates an example of a random access procedure according to one embodiment of the present disclosure. FIG. 33 illustrates signal exchange between a base station (3020) and a terminal (3010) for the random access procedure.

[0284] Referring to FIG. 33, in step S3301, the base station (3320) transmits a synchronization signal to the terminal (3310). The synchronization signal may be repeatedly transmitted using multiple beams, and depending on the direction of the beam, the synchronization signals may have different indices. At this time, at least one of the beams carrying the synchronization signal may be transmitted via a multi-beam. Accordingly, the terminal (3310) can obtain synchronization with the base station (3320).

[0285] In step S3303, the terminal (3310) acquires system information. The system information includes information necessary for connecting to the base station (3320). For example, at least a portion of the system information may be received together with the synchronization signal. Here, "received together" means that the synchronization signal is received through a beam carrying the synchronization signal, and through a resource at a relative location determined based on the resource to which the synchronization signal is mapped.

[0286] In step S3305, the terminal (3310) transmits a RACH preamble to the base station (3320). The terminal (3310) checks the configuration information for the RACH included in the system information received in step S3303, and transmits the RACH preamble through the RACH confirmed by the configuration information. At this time, the RO (RACH ocassion) to which the RACH preamble is mapped is associated with the synchronization signal received in step S3301. Specifically, the terminal (3310) can measure the RSRP of at least one synchronization signal, and then transmit the RACH preamble through the RO corresponding to the synchronization signal received through the best beam. That is, there is a one-to-one mapping between the received synchronization signal and the RACH preamble. Through this, the terminal (3310) can report the optimal beam to the base station (3320).

[0287]

[0288] Figure 34 illustrates an example of a random access procedure using an auxiliary node according to one embodiment of the present disclosure. Figure 33 illustrates signal exchange between a base station (3420), a terminal (3410), and an auxiliary node (3450) for the random access procedure. In the present embodiment, the terminal (3410) is located within the coverage area of ​​the auxiliary node (3450).

[0289] Referring to FIG. 34, in step S3401, the base station (3420) and the auxiliary node (3450) establish a connection. The connection between the base station (3420) and the auxiliary node (3450) may be based on a wired channel or a wireless channel. If based on a wireless channel, the base station (3420) and the auxiliary node (3450) may establish the connection using a random access procedure. By establishing the connection, the base station (3420) obtains a control link capable of controlling the auxiliary node (3450).

[0290] In step S3403, the base station (3420) transmits a synchronization signal to the terminal (3410). At this time, the terminal (3410) detects the synchronization signal received via the auxiliary node (3050). The synchronization signal may be repeatedly transmitted using multiple beams, and depending on the direction of the beam, the synchronization signals may have different indices. At this time, at least one of the beams carrying the synchronization signal may be transmitted via a multi-beam. The terminal (3410) may receive the synchronization signal reflected or amplified by the auxiliary node (3050). Accordingly, the terminal (3410) may obtain synchronization with the base station (3420).

[0291] In step S3405, the terminal (3410) acquires system information. The system information includes information necessary for connecting to the base station (3420). For example, at least a portion of the system information may be received together with the synchronization signal. Here, "received together" means that the synchronization signal is received through a beam carrying the synchronization signal, and through a resource at a relative location determined based on the resource to which the synchronization signal is mapped.

[0292] In step S3407, the terminal (3410) transmits a RACH preamble to the base station (3420) via the auxiliary node (3050). The terminal (3410) checks the configuration information for the RACH included in the system information received in step S3403, and transmits the RACH preamble through the RACH confirmed by the configuration information. At this time, the RO (RACH occasion) to which the RACH preamble is mapped is associated with the synchronization signal received in step S3401. Specifically, the terminal (3410) can measure the RSRP of at least one synchronization signal, and then transmit the RACH preamble through the RO corresponding to the synchronization signal received through the best beam. That is, there is a one-to-one mapping between the received synchronization signal and the RACH preamble. Through this, the terminal (3110) can report the optimal beam to the base station (3120).

[0293]

[0294] As in the embodiments described with reference to FIG. 33 or FIG. 34, a terminal can access a base station using a synchronization signal transmitted via multiple beams, and can also report a preferred beam to the base station. That is, the terminal can perform an initial beam acquisition procedure using the synchronization signal.

[0295] However, to ensure coverage, the beam carrying the synchronization signal (e.g., SSB beam) may be relatively wide, and thus the SSB beam may not be the optimal beam pair for data transmission and reception. Therefore, after performing the initial beam acquisition procedure using SSB beams, fine beams that can provide high directivity and gain may be used. In some cases, the base station and the terminal may be connected through the wide SSB beam, or the base station and the terminal may be connected through an auxiliary node. Specifically, the terminal measures RSRP and / or RSRQ using the synchronization signal included in the SSB, etc., measures the DM-RS of the PBCH, and selects the SSB received through the best beam. The terminal that has received the RACH configuration information through SIB1 can transmit the RACH preamble based on the selected SSB.

[0296] The beam used up to the RACH preamble transmission is an SSB beam belonging to a wide beam. Operations for establishing a connection through signaling such as MSG2 (e.g., RAR message) and MSG3 (e.g., connection request message) can be performed using a UE-specific beam and a beam for CSI RS. For example, within the angular range of the beam selected in the initial beam acquisition procedure, finer beams can be transmitted in different directions through a set of reference signal resources. In this case, the UE can measure RSRP using each of the CSI-RS beams, and a best beam pair can be determined. Even in an environment where a wide SSB beam or an SSB split beam including a null region according to the various embodiments described above is used, a best beam pair can be determined in a similar manner. Beam management using fine beams can be performed as illustrated in FIG. 35 below.

[0297] FIG. 35 illustrates an example of a beam management procedure according to one embodiment of the present disclosure. FIG. 35 illustrates signal exchange for optimal beam determination and management between a base station (3520) and a terminal (3510).

[0298] Referring to FIG. 35, in step S3501, the base station (3520) and the terminal (3510) perform a connection establishment procedure. For example, the terminal (3510) may acquire synchronization by detecting a synchronization signal, receive system information, perform a random access procedure, and establish a connection.

[0299] In step S3503, the base station (3520) transmits a request for beam and / or CSI reporting to the terminal (3510). In other words, the base station (3520) transmits configuration information related to channel measurement and reporting to the terminal (3510). In addition, the base station (3520) transmits a control signal for triggering and / or activating channel measurement to the terminal (3510).

[0300] In step S3505, the base station (3520) transmits a data signal and / or a reference signal to the terminal (3510). The base station (3520) transmits the reference signal based on the configuration information, control signal, etc. transmitted in step S3503. At this time, the reference signal may be transmitted and / or received through a relatively narrow beam compared to the synchronization signal. Accordingly, the terminal (3510) may perform measurements on the reference signal and determine a preferred beam.

[0301] In step S3507, the terminal (3510) transmits a CSI report to the base station (3520). The terminal (3510) transmits the CSI report including information related to the measurement results. For example, the CSI report may include information indicating a preferred beam (e.g., a CSI-RS resource indicator (CRI)). Furthermore, the CSI report may further include information related to channel quality.

[0302] In step S3509, the base station (3520) and the terminal (3510) perform beam management. In other words, after a preferred beam is determined, a procedure may be performed to continuously track and maintain the optimal beam. To this end, the base station (3520) may allocate reference signals for channel measurement, beam tracking, and beam failure detection. In response, the terminal (3510) may perform measurements and request beam switching, etc. from the base station (3520).

[0303] Below, examples of wireless device utilization to which various embodiments of the present disclosure are applied are described.

[0304] Figure 36 illustrates an example of a wireless device applicable to the present disclosure. The wireless device may be implemented in various forms depending on the use case / service (see Figure 1).

[0305] Referring to FIG. 36, the wireless device (200) corresponds to the wireless device (200) of FIG. 3 and may be composed of various elements, components, units / units, and / or modules. For example, the wireless device (200) may include a communication unit (210), a control unit (220), a memory unit (230), and additional elements (240). The communication unit may include a communication circuit (212) and a transceiver(s) (214). For example, the communication circuit (212) may include at least one processor (202) and / or at least one memory (204) of FIG. 3. For example, the transceiver(s) (214) may include at least one transceiver (206) and / or at least one antenna (208) of FIG. 3. The control unit (220) is electrically connected to the communication unit (210), the memory unit (230), and the additional elements (240) and controls the overall operations of the wireless device. For example, the control unit (220) can control the electrical / mechanical operations of the wireless device based on the program / code / command / information stored in the memory unit (230). In addition, the control unit (220) can transmit information stored in the memory unit (230) to an external device (e.g., another communication device) via a wireless / wired interface through the communication unit (210), or store information received from an external device (e.g., another communication device) via a wireless / wired interface in the memory unit (230).

[0306] The additional element (240) may be configured in various ways depending on the type of the wireless device. For example, the additional element (240) may include at least one of a power unit / battery, an input / output unit (I / O unit), a driving unit, and a computing unit. Although not limited thereto, the wireless device may be implemented in the form of a robot (Fig. 1, 100a), a vehicle (Fig. 1, 100b-1, 100b-2), an XR device (Fig. 1, 100c), a portable device (Fig. 1, 100d), a home appliance (Fig. 1, 100e), an IoT device (Fig. 1, 100f), a digital broadcasting terminal, a hologram device, a public safety device, an MTC device, a medical device, a fintech device (or a financial device), a security device, a climate / environmental device, an AI server / device (Fig. 1, 400), a base station (Fig. 1, 200), a network node, etc. Wireless devices may be mobile or stationary depending on the use / service.

[0307] In FIG. 36, various elements, components, units / parts, and / or modules within the wireless device (200) may be entirely interconnected via a wired interface, or at least some may be wirelessly connected via a communication unit (210). For example, within the wireless device (200), the control unit (220) and the communication unit (210) may be wired, and the control unit (220) and a first unit (e.g., 230, 240) may be wirelessly connected via the communication unit (210). In addition, each element, component, unit / part, and / or module within the wireless device (200) may further include at least one element. For example, the control unit (220) may be composed of at least one processor set. For example, the control unit (220) may be composed of a communication control processor, an application processor, an electronic control unit (ECU), a graphics processing processor, a memory control processor, etc. As another example, the memory unit (130) may be composed of RAM (Random Access Memory), DRAM (Dynamic RAM), ROM (Read Only Memory), flash memory, volatile memory, non-volatile memory, and / or a combination thereof.

[0308] Below, the implementation example of Fig. 36 is described in more detail with reference to the drawings.

[0309] Figure 37 illustrates examples of portable devices applicable to the present disclosure. Portable devices may include smartphones, smart pads, wearable devices (e.g., smartwatches, smartglasses), and portable computers (e.g., laptops, etc.). Portable devices may be referred to as Mobile Stations (MS), User Terminals (UT), Mobile Subscriber Stations (MSS), Subscriber Stations (SS), Advanced Mobile Stations (AMS), or Wireless Terminals (WT).

[0310] Referring to FIG. 37, the portable device (200) may include an antenna unit (208), a communication unit (210), a control unit (220), a memory unit (230), a power supply unit (240a), an interface unit (240b), and an input / output unit (240c). The antenna unit (208) may be configured as a part of the communication unit (210). Blocks 210 to 230 / 240a to 240c of FIG. 37 correspond to blocks 210 to 230 / 240 of FIG. 36, respectively.

[0311] The communication unit (210) can transmit and receive signals (e.g., data, control signals, etc.) with other wireless devices and base stations. The control unit (220) can control components of the mobile device (200) to perform various operations. The control unit (220) can include an AP (Application Processor). The memory unit (230) can store data / parameters / programs / codes / commands required for operating the mobile device (200). In addition, the memory unit (230) can store input / output data / information, etc. The power supply unit (240a) supplies power to the mobile device (200) and can include a wired / wireless charging circuit, a battery, etc. The interface unit (240b) can support connection between the mobile device (200) and other external devices. The interface unit (240b) can include various ports (e.g., audio input / output ports, video input / output ports) for connection with external devices. The input / output unit (240c) can input or output video information / signals, audio information / signals, data, and / or information input from a user. The input / output unit (240c) may include a camera, a microphone, a user input unit, a display unit (240d), a speaker, and / or a haptic module.

[0312] For example, in the case of data communication, the input / output unit (240c) obtains information / signals (e.g., touch, text, voice, image, video) input by the user, and the obtained information / signals can be stored in the memory unit (230). The communication unit (210) converts the information / signals stored in the memory into wireless signals, and can directly transmit the converted wireless signals to other wireless devices or to a base station. In addition, the communication unit (210) can receive wireless signals from other wireless devices or base stations, and then restore the received wireless signals to the original information / signals. The restored information / signals can be stored in the memory unit (230) and then output in various forms (e.g., text, voice, image, video, haptic) through the input / output unit (240c).

[0313] Figure 38 illustrates examples of vehicles or autonomous vehicles applicable to the present disclosure. The vehicles or autonomous vehicles may be implemented as mobile robots, cars, trains, manned / unmanned aerial vehicles (AVs), ships, etc.

[0314] Referring to FIG. 38, a vehicle or autonomous vehicle (200-1) may include an antenna unit (208-1), a communication unit (210-1), a control unit (220-1), a driving unit (240a-1), a power supply unit (240b-1), a sensor unit (240c-1), and an autonomous driving unit (240d-1). The antenna unit (208-1) may be configured as a part of the communication unit (210-1). Blocks 210-1 / 230-1 / 240a-1 to 240d-1 of FIG. 38 correspond to blocks 210 / 230 / 240 of FIG. 36, respectively.

[0315] The communication unit (210-1) can transmit and receive signals (e.g., data, control signals, etc.) with external devices such as other vehicles, base stations (e.g., base stations, roadside base stations (ROS), etc.), and servers. The control unit (220-1) can control elements of the vehicle or autonomous vehicle (200-1) to perform various operations. The control unit (220-1) may include an ECU (Electronic Control Unit). The drive unit (240a-1) can drive the vehicle or autonomous vehicle (200-1) on the ground. The drive unit (240a-1) may include an engine, a motor, a power train, wheels, brakes, a steering device, etc. The power supply unit (240b-1) supplies power to the vehicle or autonomous vehicle (200-1) and may include a wired / wireless charging circuit, a battery, etc. The sensor unit (240c-1) can obtain vehicle status, surrounding environment information, user information, etc. The sensor unit (240c-1) may include an IMU (inertial measurement unit) sensor, a collision sensor, a wheel sensor, a speed sensor, an incline sensor, a weight detection sensor, a heading sensor, a position module, a vehicle forward / backward sensor, a battery sensor, a fuel sensor, a tire sensor, a steering sensor, a temperature sensor, a humidity sensor, an ultrasonic sensor, an illuminance sensor, a pedal position sensor, etc. The autonomous driving unit (240d-1) may implement a technology for maintaining a driving lane, a technology for automatically controlling speed such as adaptive cruise control, a technology for automatically driving along a set path, a technology for automatically setting a path and driving when a destination is set, etc.

[0316] For example, the communication unit (210-1) can receive map data, traffic information data, etc. from an external server. The autonomous driving unit (240d-1) can generate an autonomous driving route and driving plan based on the acquired data. The control unit (220-1) can control the drive unit (240a-1) so that the vehicle or autonomous vehicle (200-1) moves along the autonomous driving route according to the driving plan (e.g., speed / direction control). During autonomous driving, the communication unit (210-1) can irregularly / periodically acquire the latest traffic information data from an external server and can acquire surrounding traffic information data from surrounding vehicles. In addition, during autonomous driving, the sensor unit (240c-1) can acquire vehicle status and surrounding environment information. The autonomous driving unit (240d-1) can update the autonomous driving route and driving plan based on newly acquired data / information. The communication unit (210-1) can transmit information regarding the vehicle location, autonomous driving route, driving plan, etc. to an external server. The external server can predict traffic information data in advance using AI technology, etc. based on information collected from the vehicle or autonomous vehicles, and provide the predicted traffic information data to the vehicle or autonomous vehicles. If the device (220-2) is an autonomous vehicle, it can perform the same procedure as the vehicle or autonomous vehicle (200-1). In addition, if the device (220-2) is a base station or a roadside base station, the device (220-2) can transmit data, control signals, etc. to the vehicle or autonomous vehicle (200-1) through the communication unit (210-2).

[0317] Figure 39 illustrates an example of a vehicle applicable to the present disclosure. The vehicle may also be implemented as a means of transportation, a train, an aircraft, a ship, etc. Referring to Figure 39, the vehicle (200) may include a communication unit (210), a control unit (220), a memory unit (230), an input / output unit (240a), and a position measurement unit (240b). Here, blocks 210 to 230 / 240a to 240b correspond to blocks 210 to 230 / 240 of Figure 36, respectively.

[0318] The communication unit (210) can transmit and receive signals (e.g., data, control signals, etc.) with other vehicles or external devices such as base stations. The control unit (220) can control components of the vehicle (200) to perform various operations. The memory unit (230) can store data / parameters / programs / codes / commands that support various functions of the vehicle (100). The input / output unit (240a) can output AR / VR objects based on information in the memory unit (230). The input / output unit (240a) can include a HUD. The position measurement unit (240b) can obtain position information of the vehicle (200). The position information can include absolute position information of the vehicle (200), position information within a driving line, acceleration information, position information with respect to surrounding vehicles, etc. The position measurement unit (240b) can include GPS and various sensors.

[0319] For example, the communication unit (210) of the vehicle (200) can receive map information, traffic information, etc. from an external server and store them in the memory unit (230). The location measurement unit (240b) can obtain vehicle location information through GPS and various sensors and store the information in the memory unit (230). The control unit (220) can create a virtual object based on the map information, traffic information, and vehicle location information, and the input / output unit (240a) can display the created virtual object on the vehicle window (240a-1, 240a-2). In addition, the control unit (220) can determine whether the vehicle (200) is being driven normally within the driving line based on the vehicle location information. If the vehicle (200) abnormally deviates from the driving line, the control unit (220) can display a warning on the vehicle window through the input / output unit (240a). Additionally, the control unit (220) can broadcast a warning message regarding driving abnormalities to surrounding vehicles through the communication unit (210). Depending on the situation, the control unit (220) can transmit vehicle location information and information regarding driving / vehicle abnormalities to relevant authorities through the communication unit (210).

[0320] Figure 40 illustrates examples of XR devices applicable to the present disclosure. The XR devices may be implemented as HMDs, head-up displays (HUDs) installed in vehicles, televisions, smartphones, computers, wearable devices, home appliances, digital signage, vehicles, robots, and the like.

[0321] Referring to FIG. 40, the XR device (200a) may include a communication unit (210), a control unit (220), a memory unit (230), an input / output unit (240a), a sensor unit (240b), and a power supply unit (240c). Here, blocks 210 to 230 / 240a to 240c of FIG. 40 correspond to blocks 210 to 230 / 240 of FIG. 36, respectively.

[0322] The communication unit (210) can transmit and receive signals (e.g., media data, control signals, etc.) with external devices such as other wireless devices, portable devices, or media servers. The media data can include videos, images, sounds, etc. The control unit (220) can control components of the XR device (200a) to perform various operations. For example, the control unit (220) can be configured to control and / or perform procedures such as video / image acquisition, (video / image) encoding, metadata generation and processing, etc. The memory unit (230) can store data / parameters / programs / codes / commands required for driving the XR device (200a) / generating XR objects. The input / output unit (240a) can obtain control information, data, etc. from the outside, and output the generated XR object. The input / output unit (240a) can include a camera, a microphone, a user input unit, a display unit, a speaker, and / or a haptic module. The sensor unit (240b) can obtain the XR device status, surrounding environment information, user information, etc. The sensor unit (240b) may include a proximity sensor, an illuminance sensor, an acceleration sensor, a magnetic sensor, a gyro sensor, an inertial sensor, an RGB sensor, an IR sensor, a fingerprint recognition sensor, an ultrasonic sensor, a light sensor, a microphone, and / or a radar. The power supply unit (240c) supplies power to the XR device (200a) and may include a wired / wireless charging circuit, a battery, etc.

[0323] For example, the memory unit (230) of the XR device (200a) may include information (e.g., data, etc.) required for creating an XR object (e.g., AR / VR / MR object). The input / output unit (240a) may obtain a command to operate the XR device (200a) from the user, and the control unit (220) may operate the XR device (200a) according to the user's operating command. For example, when the user attempts to watch a movie, news, etc. through the XR device (200a), the control unit (220) may transmit content request information to another device (e.g., a mobile device (200b)) or a media server through the communication unit (230). The communication unit (230) may download / stream content such as movies and news from another device (e.g., a mobile device (200b)) or a media server to the memory unit (230). The control unit (220) controls and / or performs procedures such as video / image acquisition, (video / image) encoding, and metadata generation / processing for content, and can generate / output an XR object based on information about surrounding space or real objects acquired through the input / output unit (240a) / sensor unit (240b).

[0324] In addition, the XR device (200a) is wirelessly connected to the mobile device (200b) through the communication unit (210), and the operation of the XR device (200a) can be controlled by the mobile device (200b). For example, the mobile device (200b) can act as a controller for the XR device (200a). To this end, the XR device (200a) can obtain 3D location information of the mobile device (200b), and then generate and output an XR object corresponding to the mobile device (200b).

[0325] Figure 41 illustrates examples of robots applicable to the present disclosure. Robots can be classified into industrial, medical, household, and military types, depending on their intended use or field.

[0326] Referring to FIG. 41, the robot (200) may include a communication unit (210), a control unit (220), a memory unit (230), an input / output unit (240a), a sensor unit (240b), and a driving unit (240c). Here, blocks 210 to 230 / 240a to 240c of FIG. 41 correspond to blocks 210 to 230 / 240 of FIG. 36, respectively.

[0327] The communication unit (210) can transmit and receive signals (e.g., driving information, control signals, etc.) with external devices such as other wireless devices, other robots, or control servers. The control unit (220) can control components of the robot (200) to perform various operations. The memory unit (230) can store data / parameters / programs / codes / commands that support various functions of the robot (200). The input / output unit (240a) can obtain information from the outside of the robot (200) and output information to the outside of the robot (200). The input / output unit (240a) can include a camera, a microphone, a user input unit, a display unit, a speaker, and / or a haptic module. The sensor unit (240b) can obtain internal information of the robot (200), surrounding environment information, user information, etc. The sensor unit (240b) may include a proximity sensor, an illuminance sensor, an acceleration sensor, a magnetic sensor, a gyro sensor, an inertial sensor, an IR sensor, a fingerprint recognition sensor, an ultrasonic sensor, a light sensor, a microphone, a radar, etc. The driving unit (240c) may perform various physical operations, such as moving the robot joints. In addition, the driving unit (240c) may enable the robot (200) to drive on the ground or fly in the air. The driving unit (240c) may include an actuator, a motor, wheels, brakes, propellers, etc.

[0328] Figure 42 illustrates an example of an AI device applicable to the present disclosure.

[0329] AI devices can be implemented as fixed or mobile devices, such as TVs, projectors, smartphones, PCs, laptops, digital broadcasting terminals, tablet PCs, wearable devices, set-top boxes (STBs), radios, washing machines, refrigerators, digital signage, robots, and vehicles.

[0330] Referring to FIG. 42, the AI ​​device (200) may include a communication unit (210), a control unit (220), a memory unit (230), an input / output unit (240a / 240b), a learning processor unit (240c), and a sensor unit (240d). Blocks 210 to 230 / 240a to 240d of FIG. 42 correspond to blocks 210 to 230 / 140 of FIG. 36, respectively.

[0331] The communication unit (210) can transmit and receive wired and wireless signals (e.g., sensor information, user input, learning models, control signals, etc.) with external devices such as other AI devices (e.g., 100a to 100f, 120 of FIG. 1) or AI servers (e.g., 100g of FIG. 1) using wired and wireless communication technology. To this end, the communication unit (210) can transmit information within the memory unit (230) to the external device or transfer a signal received from the external device to the memory unit (230).

[0332] The control unit (220) may determine at least one executable operation of the AI ​​device (200) based on information determined or generated using a data analysis algorithm or a machine learning algorithm. In addition, the control unit (220) may control components of the AI ​​device (200) to perform the determined operation. For example, the control unit (220) may request, search, receive, or utilize data from the learning processor unit (240c) or the memory unit (230), and may control components of the AI ​​device (200) to perform at least one executable operation, a predicted operation, or an operation determined to be desirable. In addition, the control unit (220) may collect history information including the operation contents of the AI ​​device (200) or user feedback on the operation, and store the collected history information in the memory unit (230) or the learning processor unit (240c), or transmit the collected history information to an external device such as an AI server (FIG. 1, 100g). The collected history information may be used to update a learning model.

[0333] The memory unit (230) can store data that supports various functions of the AI ​​device (200). For example, the memory unit (230) can store data obtained from the input unit (240a), data obtained from the communication unit (210), output data of the learning processor unit (240c), and data obtained from the sensing unit (140). In addition, the memory unit (230) can store control information and / or software codes necessary for the operation / execution of the control unit (220).

[0334] The input unit (240a) can obtain various types of data from the outside of the AI ​​device (200). For example, the input unit (220) can obtain learning data for model learning, input data to which the learning model will be applied, etc. The input unit (240a) may include a camera, a microphone, and / or a user input unit. The output unit (240b) may generate output related to vision, hearing, or touch. The output unit (240b) may include a display unit, a speaker, and / or a haptic module, etc. The sensing unit (140d) can obtain at least one of internal information of the AI ​​device (200), information about the surrounding environment of the AI ​​device (200), and user information using various sensors. The sensing unit (140d) may include a proximity sensor, an illuminance sensor, an acceleration sensor, a magnetic sensor, a gyro sensor, an inertial sensor, an RGB sensor, an IR sensor, a fingerprint recognition sensor, an ultrasonic sensor, a light sensor, a microphone, and / or a radar, etc.

[0335] The learning processor unit (240c) can train a model composed of an artificial neural network using learning data. The learning processor unit (240c) can perform AI processing together with the learning processor unit of the AI ​​server (Fig. 1, 100g). The learning processor unit (240c) can process information received from an external device via the communication unit (210) and / or information stored in the memory unit (230). In addition, the output value of the learning processor unit (240c) can be transmitted to an external device via the communication unit (210) and / or stored in the memory unit (230).

[0336] The proposed methods described above can be implemented independently, but they can also be implemented as a combination (or merge) of some of the proposed methods. Rules can be defined so that the base station notifies the terminal of the applicability of the proposed methods (or information about the rules of the proposed methods) through a predefined signal (e.g., a physical layer signal or a higher layer signal).

[0337] The present disclosure may be embodied in other specific forms without departing from the technical ideas and essential features described herein. Therefore, the above detailed description should not be construed as limiting in all respects 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 equivalent scope of the present disclosure are intended to be included within the scope of the present disclosure. Furthermore, claims that are not explicitly cited in the claims may be combined to form an embodiment or incorporated into a new claim through a post-filing amendment.

[0338] Embodiments of the present disclosure can be applied to various wireless access systems. Examples of various wireless access systems include the 3rd Generation Partnership Project (3GPP) or 3GPP2 systems.

[0339] The embodiments of the present disclosure can be applied not only to the various wireless access systems described above, but also to all technical fields that utilize these various wireless access systems. Furthermore, the proposed method can also be applied to mmWave and THz communication systems utilizing ultra-high frequency bands.

[0340] Additionally, embodiments of the present disclosure can be applied to various applications such as autonomous vehicles and drones.

Claims

1. A method performed by a base station in a wireless communication system, generating at least one sequence for a synchronization signal; generating the synchronization signal based on at least one sequence; A step of determining resources for transmitting the above synchronization signal; a step of determining directions for transmitting the above synchronization signal; and A step of transmitting the synchronization signal in the directions using the above resources, The above synchronization signal is transmitted via multi-beam in at least one of a plurality of transmission opportunities, A method for transmitting the synchronization signal in a plurality of directions, the multi-beam including a first direction in which an adaptive beam for beam sweeping within the coverage of the base station is directed, and a second direction in which a fixed beam for auxiliary nodes deployed within the coverage of the base station is directed.

2. In claim 1, The above multi-beam method carries a synchronization signal of the same index in the first direction and the second direction.

3. In claim 2, A method in which the above multi-beam is formed by beamforming each of the synchronization signals of the same index processed by different RF (radio frequency) chains in the first direction and the second direction.

4. In claim 2, A method in which the above multi-beam is formed by beamforming one synchronization signal generated by one RF chain in the first direction and the second direction.

5. In claim 4, The step of transmitting the synchronization signal in the above directions is: A step of identifying phase patterns for the above directions; A step of determining a combined phase pattern and a scattering vector for beam scattering based on the above phase patterns; A method comprising the step of applying the combined phase pattern and the scattering vector to antenna elements of the antenna array.

6. In claim 5, A method in which the above combined phase pattern is determined by weighted summing of phase values ​​included in the above phase patterns for each antenna element.

7. In claim 6, The above weighted summation method includes averaging.

8. In claim 5, The above scattering vector is determined by a cosine operation on the weighted sum of phase values ​​included in the above phase patterns for each antenna element.

9. In claim 8, The weights for the above weighted sum include negative numbers, The sum of the absolute values ​​of the above weights is 1.

10. In claim 8, Each of the values ​​included in the above scattering vector is determined depending on whether the result of the cosine operator is negative or positive, and includes 0 degrees or 180 degrees.

11. In a method performed by a terminal in a wireless communication system, A step of determining resources for synchronization signals; A step of receiving the synchronization signal using the above resources; A step of obtaining synchronization for a base station using the above synchronization signal; A step of receiving system information from the base station; and A step of performing a connection procedure based on the above system information is included. The above synchronization signal is transmitted by the base station via multi-beam in at least one of a plurality of transmission opportunities, A method for transmitting the synchronization signal in a plurality of directions, the multi-beam including a first direction in which an adaptive beam for beam sweeping within the coverage of the base station is directed, and a second direction in which a fixed beam for auxiliary nodes deployed within the coverage of the base station is directed.

12. In a base station in a wireless communication system, Transmitter and receiver; and comprising a processor connected to the above transceiver, The above processor, Generate at least one sequence for the synchronization signal, Generating the synchronization signal based on at least one sequence, Determine the resources for transmitting the above synchronization signal, Determine the directions for transmitting the above synchronization signal, configured to transmit the synchronization signal in the above directions using the above resources, The above synchronization signal is transmitted via multi-beam in at least one of a plurality of transmission opportunities, A base station wherein the multi-beam carries the synchronization signal in a plurality of directions, including a first direction in which an adaptive beam for beam sweeping within the coverage of the base station is directed, and a second direction in which a fixed beam for auxiliary nodes deployed within the coverage of the base station is directed.

13. In a wireless communication system, at a terminal, Transmitter and receiver; and comprising a processor connected to the above transceiver, The above processor, Determine the resources for the synchronization signal, Receive the synchronization signal using the above resources, Acquire synchronization with the base station using the above synchronization signal, Receive system information from the above base station, It is configured to perform a connection procedure based on the above system information, The above synchronization signal is transmitted by the base station via multi-beam in at least one of a plurality of transmission opportunities, The multi-beam terminal carries the synchronization signal in a plurality of directions, including a first direction toward which an adaptive beam for beam sweeping within the coverage of the base station is directed, and a second direction toward which a fixed beam for an auxiliary node deployed within the coverage of the base station is directed.

14. In communication devices, At least one processor; At least one computer memory connected to said at least one processor and storing instructions that direct operations when executed by said at least one processor, The above actions are, generating at least one sequence for a synchronization signal; generating the synchronization signal based on at least one sequence; A step of determining resources for transmitting the above synchronization signal; a step of determining directions for transmitting the above synchronization signal; and A step of transmitting the synchronization signal in the directions using the above resources, The above synchronization signal is transmitted via multi-beam in at least one of a plurality of transmission opportunities, A communication device wherein the multi-beam carries the synchronization signal in a plurality of directions, including a first direction in which an adaptive beam for beam sweeping within the coverage of the communication device is directed, and a second direction in which a fixed beam for an auxiliary node positioned within the coverage of the communication device is directed.

15. In a non-transitory computer-readable medium storing at least one instruction, comprising at least one instruction executable by the processor, At least one of the above commands causes the device to: Generate at least one sequence for the synchronization signal, Generating the synchronization signal based on at least one sequence, Determine the resources for transmitting the above synchronization signal, Determine the directions for transmitting the above synchronization signal, Instructs to transmit the synchronization signal in the above directions using the above resources, The above synchronization signal is transmitted via multi-beam in at least one of a plurality of transmission opportunities, A non-transitory computer-readable medium in which the multi-beam carries the synchronization signal in a plurality of directions, including a first direction in which an adaptive beam for beam sweeping within the coverage of the base station is directed, and a second direction in which a fixed beam for auxiliary nodes deployed within the coverage of the base station is directed.

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