Device and method for performing wireless communication using simultaneously transmitting and reflecting reconfigurable intelligent surface in wireless communication system

Abstract

The present disclosure is for performing wireless communication using a simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS) in a wireless communication system. A method performed by a terminal in a wireless communication system may comprise the steps of: receiving system information from a base station; performing an initial access procedure with the base station on the basis of the system information; receiving configuration information about channel measurement from the base station; performing a channel measurement procedure on the basis of the configuration information; receiving a control signal from the base station; and transmitting or receiving, on the basis of the control signal, a data signal to or from the base station by using at least one of a plurality of subcarriers.

Description

Device and method for performing wireless communication using a reconfigurable intelligent surface that simultaneously transmits and reflects in a wireless communication system

[0001] The present disclosure relates to a wireless communication system, and more particularly, to a device and method for performing wireless communication using a simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS) in a wireless communication system using an intelligent surface.

[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, communication systems that consider reliability and latency-sensitive services / user equipment (UE) as well as massive machine type communications (mMTC), which connects numerous devices and objects to provide diverse services anytime and anywhere, are being proposed. Various technological configurations are being proposed for these solutions.

[0004] The present disclosure relates to a device and method for a wireless communication system.

[0005] The present disclosure relates to a device and method for performing wireless communication using a simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS) in a wireless communication system.

[0006] The present disclosure relates to a device and method for allocating subcarriers for a terminal included in a transmission area and a terminal included in a reflection area to passive elements of STAR-RIS in a wireless communication system.

[0007] The present disclosure relates to a device and method for performing wireless communication based on assigning a plurality of subcarriers to each of a plurality of terminals in a wireless communication system.

[0008] The present disclosure relates to a device and method for allocating subcarriers allocated to terminals included in a transmission area group and subcarriers included in a reflection area group to each of the passive elements of STAR-RIS in a wireless communication system.

[0009] The present disclosure relates to a device and method for determining transmission coefficients and reflection coefficients of STAR-RIS based on a summation transmission rate in a wireless communication system.

[0010] The present disclosure relates to a device and method for determining transmission coefficients and reflection coefficients of STAR-RIS with lower complexity than a convex optimization technique in a wireless communication system.

[0011] The present disclosure relates to a device and a method for determining the phase of a transmission coefficient of STAR-RIS in a wireless communication system based on the transmission rates of transmission area groups and determining the phase of a reflection coefficient based on the transmission rates of reflection area groups.

[0012] The present disclosure relates to a device and a method for determining the size of a transmission coefficient and a reflection coefficient of STAR-RIS in a wireless communication system based on the amount of change in the sum transmission rate of subcarriers allocated to each passive element.

[0013] The present disclosure relates to a device and method for classifying terminals into a transmission area group and a reflection area group based on the received signal received power (RSRP) of a reference signal in a wireless communication system.

[0014] 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.

[0015] As an example of the present disclosure, a method of operation performed by a terminal in a wireless communication system includes the steps of: receiving system information from a base station; performing an initial connection procedure with the base station based on the system information; receiving configuration information regarding channel measurement from the base station; performing a channel measurement procedure based on the configuration information; receiving a control signal from the base station; and transmitting or receiving a data signal to the base station using at least one subcarrier among a plurality of subcarriers based on the control signal, wherein the data signal is transmitted or received through a simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS), and control information for passive elements of the STAR-RIS can be determined based on a transmission rate for a transmission area group and a transmission rate for a reflection area group.

[0016] As an example of the present disclosure, a method of operation performed by a base station in a wireless communication system includes the steps of transmitting system information to a terminal, performing an initial connection procedure with the terminal, transmitting configuration information regarding channel measurement to the terminal, performing a channel measurement procedure based on the configuration information, transmitting a control signal to the terminal, transmitting control information for passive elements to a STAR-RIS (simultaneously transmitting and reflecting reconfigurable intelligent surface), and transmitting or receiving a data signal from the terminal using at least one subcarrier among a plurality of subcarriers, wherein the data signal is transmitted or received through the STAR-RIS, and the control information for the passive elements can be determined based on a transmission rate for a transmission area group and a transmission rate for a reflection area group.

[0017] 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 receive system information from a base station, perform an initial connection procedure with the base station based on the system information, receive configuration information regarding channel measurement from the base station, perform a channel measurement procedure based on the configuration information, receive a control signal from the base station, and transmit or receive a data signal to the base station using at least one subcarrier among a plurality of subcarriers based on the control signal, wherein the data signal is transmitted or received through a simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS), and control information for passive elements of the STAR-RIS can be determined based on a transmission rate for a transmission area group and a transmission rate for a reflection area group.

[0018] As an example of the present disclosure, in a wireless communication system, a base station includes a transceiver and a processor connected to the transceiver, wherein the processor is configured to transmit system information to a terminal, perform an initial connection procedure with the terminal, transmit configuration information regarding channel measurement to the terminal, perform a channel measurement procedure based on the configuration information, transmit a control signal to the terminal, transfer control information for passive elements to a STAR-RIS (simultaneously transmitting and reflecting reconfigurable intelligent surface), and transmit or receive a data signal from the terminal using at least one subcarrier among a plurality of subcarriers, wherein the data signal is transmitted or received through the STAR-RIS, and the control information for the passive elements can be determined based on a transmission rate for a transmission area group and a transmission rate for a reflection area group.

[0019] As an example of the present disclosure, a communication device comprises at least one processor, at least one computer memory connected to the at least one processor and storing instructions that direct operations when executed by the at least one processor, the operations including: receiving system information from a base station; performing an initial connection procedure with the base station based on the system information; receiving configuration information regarding channel measurement from the base station; performing a channel measurement procedure based on the configuration information; receiving a control signal from the base station; and transmitting or receiving a data signal to the base station using at least one subcarrier among a plurality of subcarriers based on the control signal, wherein the data signal is transmitted or received through a simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS), and control information for passive elements of the STAR-RIS can be determined based on a transmission rate for a transmission area group and a transmission rate for a reflection area group.

[0020] As an example of the present disclosure, a non-transitory computer-readable medium storing at least one instruction, the at least one instruction being executable by a processor, wherein the at least one instruction configures a device to receive system information from a base station, perform an initial connection procedure with the base station based on the system information, receive configuration information regarding channel measurement from the base station, perform a channel measurement procedure based on the configuration information, receive a control signal from the base station, and transmit or receive a data signal to the base station using at least one subcarrier among a plurality of subcarriers based on the control signal, wherein the data signal is transmitted or received through a simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS), and control information for passive elements of the STAR-RIS can be determined based on a transmission rate for a transmission area group and a transmission rate for a reflection area group.

[0021] 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.

[0022] The following effects may be achieved by embodiments based on the present disclosure.

[0023] According to the present disclosure, in a wireless communication system utilizing STAR-RIS (simultaneously transmitting and reflecting reconfigurable intelligent surface), STAR-RIS can be efficiently controlled based on a passive element allocation technique.

[0024] 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.

[0025] 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.

[0026] Figure 1 illustrates an example of a communication system applicable to the present disclosure.

[0027] FIG. 2 illustrates an example of a wireless device applicable to the present disclosure.

[0028] FIG. 3 illustrates a method for processing a transmission signal applicable to the present disclosure.

[0029] FIG. 4 illustrates an example of a communication structure that can be provided in a 6G (6th generation) system applicable to the present disclosure.

[0030] Figure 4 illustrates a communication procedure between a terminal and a base station applicable to the present disclosure.

[0031] FIG. 5 illustrates an example of a communication structure that can be provided in a 6G (6th generation) system applicable to the present disclosure.

[0032] Figure 6 illustrates an electromagnetic spectrum applicable to the present disclosure.

[0033] Figure 7 illustrates a THz communication method applicable to the present disclosure.

[0034] Figure 8 illustrates a THz signal generation method applicable to the present disclosure.

[0035] FIG. 9 illustrates a wireless communication transceiver applicable to the present disclosure.

[0036] Figure 10 illustrates a transmitter structure applicable to the present disclosure.

[0037] Figure 11 illustrates a system information transmission procedure applicable to the present disclosure.

[0038] Figure 12 illustrates a beam management procedure applicable to the present disclosure.

[0039] FIG. 13 illustrates an example of a downlink communication environment using STAR-RIS (simultaneously transmitting and reflecting reconfigurable intelligent surface) according to one embodiment of the present disclosure.

[0040] FIG. 14 illustrates an example of a procedure in which a terminal transmits and / or receives a data signal via STAR-RIS according to one embodiment of the present disclosure.

[0041] FIG. 15 illustrates an example of a procedure in which a base station transmits and / or receives a data signal via STAR-RIS according to one embodiment of the present disclosure.

[0042] FIG. 16 illustrates an example of a procedure in which a base station determines control values ​​of STAR-RIS based on channel estimation according to one embodiment of the present disclosure.

[0043] FIG. 17 illustrates an example of a procedure for a base station to control STAR-RIS for a downlink signal according to one embodiment of the present disclosure.

[0044] FIG. 18 illustrates an example of an algorithm for optimizing reflection coefficients and transmission coefficients for a downlink signal according to one embodiment of the present disclosure.

[0045] FIG. 19 illustrates an example of a timing diagram according to one embodiment of the present disclosure.

[0046] FIG. 20 illustrates an example of signaling for transmitting and / or receiving a data signal in a communication environment in which STAR-RIS is used according to one embodiment of the present disclosure.

[0047] FIG. 21 illustrates an example of signaling for terminals included in different areas to transmit and / or receive data signals using STAR-RIS according to one embodiment of the present disclosure.

[0048] FIG. 22 illustrates an example of a summation transmission rate according to the number of passive elements of STAR-RIS according to one embodiment of the present disclosure.

[0049] FIG. 23 illustrates an example of a sum transmission rate according to a maximum transmission power according to an embodiment of the present disclosure.

[0050] Figure 24 illustrates an example of a wireless device applicable to the present disclosure.

[0051] Figure 25 illustrates an example of a portable device applicable to the present disclosure.

[0052] FIG. 26 illustrates an example of a vehicle or autonomous vehicle applicable to the present disclosure.

[0053] Figure 27 illustrates an example of a vehicle applicable to the present disclosure.

[0054] FIG. 28 illustrates an example of an XR device applicable to the present disclosure.

[0055] Figure 29 illustrates an example of a robot applicable to the present disclosure.

[0056] Figure 30 illustrates an example of an AI device applicable to the present disclosure.

[0057] The following embodiments combine 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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).

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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).

[0070]

[0071] 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.

[0072] 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.

[0073]

[0074] Communication system applicable to the present disclosure

[0075] 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.

[0076] 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.

[0077] Figure 1 illustrates an example of a communication system applied to the present disclosure.

[0078] 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.

[0079] 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).

[0080] 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.

[0081]

[0082] Devices applicable to the present disclosure

[0083] FIG. 2 illustrates an example of a wireless device applicable to the present disclosure.

[0084] 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).

[0085] 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.

[0086] 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.

[0087] 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 executed 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.

[0088] 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.

[0089] 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.

[0090] 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).

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098]

[0099] 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, for example, the operations / functions of FIG. 3 may be performed in the processor (202) and / or the transceiver (206) of FIG. 2. Furthermore, for example, the hardware elements of FIG. 3 may be implemented in the processor (202) and / or the transceiver (206) of FIG. 2. For 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.

[0100] 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., learning 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104]

[0105] 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.

[0106] 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).

[0107] 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112]

[0113] 6G communication systems and core implementation technologies of 6G systems

[0114] 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.

[0115] 6G systems utilizing the THz frequency band are aimed at i) very high data rates per device, ii) a very large number of connected devices, iii) global connectivity, iv) very low latency, v) reducing 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.

[0116] Per device peak data rate1 TbpsE2E latency1 msMaximum spectral efficiency100 bps / HzMobility supportup to 1000 km / hrSatellite integrationFullyAIFullyAutonomous vehicleFullyXRFullyHaptic CommunicationFully

[0117] 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:

[0118] - 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.

[0119] 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).

[0120] - 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.

[0121] - 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.

[0122] Some general requirements for the new network characteristics of 6G, such as the above, may be as follows:

[0123] - 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.

[0124] 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.

[0125] 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.

[0126] - 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.

[0127] - 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.

[0128] 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).

[0129] 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.

[0130]

[0131] 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.

[0132] 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.

[0133] 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.

[0134] 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

[0135] 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.

[0136] Figure 10 illustrates a transmitter structure applicable to the present disclosure.

[0137] 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.

[0138] 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.

[0139] 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.

[0140] 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. Based on an outdoor scenario, the available bandwidth can be classified 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.

[0141] 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.

[0142] 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).

[0143]

[0144] 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.

[0145] 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 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.

[0146] 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.

[0147] 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.

[0148] 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).

[0149]

[0150] 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.

[0151] 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.

[0152] 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.

[0153] 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).

[0154] 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.

[0155] Specific embodiments of the present disclosure

[0156] In existing communication systems, each endpoint can be controlled to optimize the channel environment while maintaining a fixed channel environment. Therefore, the transmitter and receiver must optimize to adapt to the channel and transmit and / or receive data. However, in environments with high signal loss and low multipath, such as NLOS (non-line of sight) in shaded areas or 6G THz, endpoint optimization alone may not be enough to overcome Shannon's capacity limit, making it difficult to achieve the required throughput.

[0157] For post-5G mobile communications, various wireless communication technologies have been developed, including massive multiple-input multiple-output (MIMO), terahertz (THz) communication systems, and reconfigurable intelligent surfaces (RIS). In particular, RIS, which consists solely of passive elements, can increase data transmission rates with low cost and low energy consumption. Here, the passive elements refer to the metasurface that constitutes RIS. RIS can intelligently reflect incident signals to enhance desired signal strength or suppress interference. RIS is typically composed of passive elements and does not perform the function of receiving and decoding signals; it only reflects the incident signal. Therefore, RIS has limitations in that it can only form a reflected signal in a specific direction based on the incident signal's angle of incidence. To overcome these limitations, STAR-RIS (simultaneously transmitting and reflecting reconfigurable intelligent surface) can be considered, which can achieve 360-degree coverage.

[0158] STAR-RIS can transmit signals to both terminals in the same direction as the incident signal and terminals in the opposite direction. That is, the incident signal can be transmitted to the terminals as a transmission signal and a reflection signal through STAR-RIS, and the transmission signal and the reflection signal can be simultaneously reconstructed through passive components. That is, the transmission signal and the reflection signal can be controlled through the transmission coefficient and reflection coefficient of STAR-RIS. In order to create an efficient wireless communication environment, research on the procedure for determining the transmission coefficient and reflection coefficient of STAR-RIS is necessary, and optimization based on convex optimization can be considered. However, the procedure for determining the transmission coefficient and reflection coefficient based on convex optimization has high complexity, so a technique with low complexity and less performance degradation may be required.

[0159] Below, a method and device for efficiently operating wireless communication using STAR-RIS are proposed. In the present disclosure, STAR-RIS is not limited to being referred to by a specific name and may be referred to by various names. For example, STAR-RIS may be referred to as STAR-IRS (simultaneously transmitting and reflecting intelligent reflect surface), bidirectional RIS, etc. In addition, the procedures related to STAR-RIS proposed in the present disclosure may be implemented as procedures for devices that perform similar functions. That is, for the convenience of explanation, the following description focuses on STAR-RIS, but may not be limited thereto.

[0160] The symbols used in this disclosure are as follows.

[0161] x: Vertical vectorx, indicated in bold.

[0162] A: Matrix A, indicated in bold.

[0163] and : Transpose and Hermitian transpose

[0164] : Magnitude, phase, and conjugate of complex number z

[0165] : set of complex numbers

[0166] : A set of complex matrices of size m × n

[0167] : Vector x value

[0168] : set The size of

[0169] : A diagonal matrix with diagonal elements

[0170] : A vector of size n×1 consisting entirely of 1s

[0171] : big-O representation

[0172] : average and dispersion Normal distribution with

[0173] The abbreviations used in this disclosure are as follows.

[0174] BS: base station

[0175] STAR-RIS: Simultaneously transmitting and reflecting-reconfigurable intelligent surface

[0176] UE: user equipment

[0177] MISO: multiple-input single-output

[0178] OFDM: orthogonal frequency division multiplexing

[0179] TDD: Time Division Duplexing

[0180] ULA: uniform linear array

[0181] UPA: uniform planar array

[0182] LoS: line of sight

[0183] DoF: degrees of freedom

[0184] The terms used in this disclosure are as follows.

[0185] : Number of antennas in BS

[0186] : Number of terminals

[0187] : Number of terminals receiving the transmitted signal

[0188] : Number of terminals receiving reflected signals

[0189] : Number of STAR-RIS elements

[0190] : Number of subcarriers in OFDM system

[0191] : Transmission coefficient

[0192] : Reflection coefficient

[0193] : Size of the mth transmission coefficient

[0194] : The magnitude of the mth reflection coefficient

[0195] : Phase of the mth transmission coefficient

[0196] : Phase of the mth reflection coefficient

[0197] : Number of channel taps between BS and kth terminal

[0198] : Number of channel taps between BS and STAR-RIS

[0199] : Channel tap number between STAR-RIS and kth terminal

[0200] : The ℓth tap of the time domain channel between the BS and the kth terminal

[0201] : The ℓth tap of the time-domain channel between BS and STAR-RIS

[0202] : The ℓth tap of the time-domain channel between STAR-RIS and the kth terminal

[0203] : Frequency domain channel between BS and kth terminal for nth subcarrier

[0204] : Frequency domain channel between BS and STAR-RIS for the nth subcarrier

[0205] : Frequency domain channel between STAR-RIS and kth terminal for nth subcarrier

[0206] : Transmission signal of the nth subcarrier of the kth terminal

[0207] : Beamformer vector of the nth subcarrier of the kth terminal

[0208] : Data stream for the nth subcarrier of the kth terminal

[0209] : Noise in the nth subcarrier of the kth terminal

[0210] : Maximum transmission power allocated to the nth subcarrier of the kth terminal

[0211] : Maximum transmission power of the base station

[0212] : Transmission rate of the nth subcarrier of the kth terminal

[0213] Since STAR-RIS can simultaneously transmit and reflect, the base station can control terminals by dividing the area into areas where transmitted signals are transmitted and areas where reflected signals are transmitted. Accordingly, the base station can control STAR-RIS components to efficiently transmit signals to terminals within a specific area.

[0214] Fig. 13 illustrates an example of a downlink communication environment using STAR-RIS (1320) according to an embodiment of the present disclosure. In the following, a signal transmitted from a base station (1310) to STAR-RIS (1320) is defined as an incident signal, a signal directed from STAR-RIS (1320) to a transmission region (T region) is defined as a transmission signal, and a signal directed from STAR-RIS (1320) to a reflection region (R region) is defined as a reflection signal. A set of terminals belonging to a transmission region is defined as , and the set of terminals belonging to the reflection area is defined as Let us define the set of all terminals as STAR-RIS (1320) is assumed to have the same characteristics at all frequencies.

[0215] In a communication environment in which STAR-RIS (1320) is operated, various paths of channels may be formed between the base station (1310), terminals (1330, 1340), and STAR-RIS (1320). For example, channels may be formed between the base station (1310) and terminals (1330, 1340), channels may be formed between the base station (1310) and STAR-RIS (1320), and channels may be formed between STAR-RIS (1320) and terminals (1330, 1340). Since the terminals (1330, 1340) may be present in a transmission area or a reflection area, various situations must be considered. For example, a signal transmitted to a first terminal (1330) existing in a reflection area can be transmitted through a path between a base station (1310) and the first terminal (1330) and a path leading to the base station (1310), STAR-RIS (1320), and the first terminal (1330), and a reflection coefficient of the STAR-RIS (1320) can be controlled to control a transmission rate for the first terminal (1330). In addition, a signal transmitted to a second terminal (1340) existing in a transmission area can be transmitted through a path between a base station (1310) and the second terminal (1340) and a path leading to the base station (1310), STAR-RIS (1320), and the second terminal (1340), and a transmission coefficient of the STAR-RIS (1320) can be controlled to control a transmission rate for the second terminal (1340).

[0216] The criteria for dividing the reflection area and the transmission area can be defined in various forms. For example, as shown in FIG. 13, the front side can be defined as the reflection area and the back side can be defined as the transmission area based on STAR-RIS. As another example, the area between the base station and STAR-RIS can be defined as the reflection area, and the area in the opposite direction from the base station based on STAR-RIS can be defined as the transmission area. Although the present disclosure has described a method for optimizing parameters for performing communication by dividing into reflection area and transmission area for convenience of explanation, it can also be applied to cases where other types of reflective surfaces are used. For example, if two areas are divided within the coverage area of ​​the base station and the phase and magnitude coefficients of the reflective surface can be controlled for each of the areas, optimization of the reflective surface can be performed through some or all of the applied procedures disclosed in the present disclosure.

[0217] STAR-RIS can be used for transmitting and receiving uplink or downlink signals. In the following, the relationship between the transmission coefficient and reflection coefficient and the transmission rate in downlink signals will be explained first. STAR-RIS is a transmission coefficient and reflection coefficient It can be controlled through, and the transmission coefficient and reflection coefficient can be defined as in [Mathematical Formula 1].

[0218]

[0219] In [Equation 1], and means the size coefficient of the mth element, and by the law of conservation of energy, Satisfies. and means the phase coefficient of the mth element. and It is assumed that it can be controlled independently from the base station.

[0220] For convenience of explanation, variable c, whose value changes depending on whether the kth terminal is included in the transmission area, is defined as in [Mathematical Formula 2] below.

[0221]

[0222] In [Mathematical Formula 2], c has a t value when the kth terminal is included in the transmission area, and has an r value when the kth terminal is included in the reflection area.

[0223] A wideband communication system may have multiple channel taps that cause inter-symbol interference (ISI). The time-domain channel of the kth terminal can be expressed as in [Mathematical Formula 3] below.

[0224]

[0225] In [Equation 3], refers to the total number of channel taps.

[0226] OFDM can be used to eliminate inter-symbol interference. Also A cyclic prefix (CP) of length can be added, and N parallel channels can be generated. The frequency domain channel can be obtained through discrete Fourier transform (DFT). The frequency domain channel of the kth terminal can be expressed as in [Mathematical Formula 4] below.

[0227]

[0228] It is assumed that only one terminal is supported in each subcarrier. The reception signal of the kth terminal in the nth subcarrier can be expressed as in [Mathematical Formula 5] below.

[0229]

[0230] Since each subcarrier is assigned to only one terminal, interference between terminals can be considered non-existent. Therefore, a maximum ratio transmission (MRT) beamformer can be determined as the optimal beamformer. When using an MRT beamformer, the transmission rate of the kth terminal corresponding to the nth subcarrier can be expressed as in [Mathematical Formula 6] below.

[0231]

[0232] That is, the transmission rate of the kth terminal can be determined by the transmission coefficient, reflection coefficient, channel between the base station and the terminal, channel between the base station and STAR-RIS, channel between STAR-RIS and the base station, etc. In addition, the uplink transmission rate can be determined in a similar manner to the method described above. In a channel reciprocity environment, it can be assumed that the uplink channel and the downlink channel are the same. In this case, the base station transmits the signal transmitted by the terminal through the nth subcarrier. In [Mathematical Formula 5] Similar to or It can be received in the form of. However, the base station can receive the uplink data signal by applying the MRC (maximum ratio combiner) beamformer for the uplink rather than the MRT beamformer for the downlink. Below, the procedure for estimating channels through the measurement procedure and controlling STAR-RIS is described.

[0233] FIG. 14 illustrates an example of a procedure for a terminal to transmit and / or receive a data signal via STAR-RIS according to one embodiment of the present disclosure. In FIG. 14 , the terminal may be either a terminal in a reflective area (e.g., terminal 1330 of FIG. 13 ) or a terminal in a transmission area (e.g., terminal 1340 of FIG. 13 ).

[0234] Referring to Figure 14, at step S1401, the terminal receives system information from the base station. The system information may include information related to the properties or characteristics of the base station using STAR-RIS. The system information may be transmitted via the master information block (MIB) and the system information block (SIB).

[0235] At step S1403, the terminal performs an initial connection procedure with the base station based on system information. To perform the initial connection procedure, the terminal may perform at least one of the operations described in FIG. 11. For example, the terminal may transmit a signal for initial connection (e.g., a random access preamble) to the base station based on system information, and receive a response signal to the initial connection signal from the base station.

[0236] In step S1405, the terminal receives configuration information regarding channel measurement from the base station. The configuration information regarding channel measurement may include at least one of information regarding the measurement target, information regarding the measurement cycle, information regarding the measurement gap, and information regarding the measurement report.

[0237] In step S1407, the terminal performs a channel measurement procedure based on the configuration information. The channel measurement may be performed by the terminal or the base station. When the measurement is performed by the terminal, the terminal receives a reference signal from the base station, and the base station receives information regarding the channel measurement from the terminal. When the measurement is performed by the base station, the terminal transmits a reference signal to the base station, and the base station can measure the channel based on the received reference signal. Based on the channel measurement information, control information for the passive components of STAR-RIS required for the base station to control STAR-RIS can be determined. At this time, the control information for the passive components of STAR-RIS can be optimized so that the transmission rate for the terminals is maximized.

[0238] In step S1409, the terminal receives a control signal from the base station. The control signal may include information about frequency resources and / or time resources for performing communication using STAR-RIS. The information about the frequency resources may include information about at least one subcarrier. At least one subcarrier may be allocated to each of the passive elements of STAR-RIS, and each of the subcarriers may be configured to support one terminal. As a result, at least one subcarrier allocated to the terminal is determined, and information about the at least one subcarrier may be directly or indirectly transmitted via the control signal.

[0239] In step S1411, the terminal transmits and / or receives a data signal via STAR-RIS based on a control signal. The terminal obtains information about at least one subcarrier assigned to it via the control signal received in step S1411, and can transmit and / or receive a data signal based on the at least one assigned subcarrier. The data signal can be transmitted and / or received via STAR-RIS controlled by the base station.

[0240] FIG. 15 illustrates an example of a procedure for a base station to transmit and / or receive a data signal via STAR-RIS according to one embodiment of the present disclosure. Referring to FIG. 15 , the base station can control passive components of STAR-RIS based on a channel measurement procedure and transmit a control signal to a terminal.

[0241] Referring to Figure 15, at step S1501, the base station transmits system information to the terminal. This system information may include information related to the properties or characteristics of the base station using STAR-RIS. The system information may be transmitted to the terminal in a broadcast format. The system information may be included in the MIB and SIB.

[0242] In step S1503, the base station performs an initial connection procedure with the terminal. To perform the initial connection procedure, the base station may receive a signal for initial connection from the terminal and transmit a response signal to the signal for initial connection to the terminal.

[0243] In step S1505, the base station transmits channel measurement configuration information to the terminal. The channel measurement configuration information may include at least one of information about the measurement target, information about the measurement cycle, information about the measurement gap, and information about the measurement report.

[0244] In step S1507, the base station performs a measurement procedure based on the configuration information. The channel measurement can be performed by the terminal or the base station. Through the measurement procedure, the base station can obtain information about the channel between the base station and the terminal, the channel between the base station and STAR-RIS, and the channel between STAR-RIS and the base station. Based on the channel measurement information, control information for the passive components of STAR-RIS required for the base station to control STAR-RIS can be determined. At this time, the control information for the passive components of STAR-RIS can be optimized so as to maximize the transmission rate for the terminals.

[0245] In step S1509, the base station transmits a control signal to the terminal. The control signal may include information regarding frequency resources or time resources for performing communication using STAR-RIS. To determine the frequency resources allocated to the terminal, the base station may assign at least one of a plurality of subcarriers to the terminal based on channel measurements.

[0246] In step S1511, the base station transmits and / or receives a data signal from the terminal via the STAR-RIS. The base station can control the STAR-RIS to transmit and / or receive the data signal. To control the STAR-RIS, control information for the passive elements can be determined. Since the STAR-RIS can simultaneously transmit and reflect an incident signal, the control information for the passive elements can include information about a transmission coefficient and a reflection coefficient. The method of transmitting the control information for the passive elements of the STAR-RIS is not limited to a specific method, and can be transmitted via a wireless channel or a wired channel, etc. For example, when the STAR-RIS includes a STAR-RIS controller, the base station transmits the control information to the STAR-RIS controller, and the STAR-RIS controller can change the characteristics of the passive elements of the STAR-RIS based on the control information. As another example, when there is no STAR-RIS controller, the base station can directly control the STAR-RIS passive elements based on the STAR-RIS control information.

[0247] For efficient data signal transmission, a procedure for determining control information for controlling STAR-RIS may be required. Below, a procedure for determining control information for a base station to control STAR-RIS is described. The control information may include transmission coefficients and reflection coefficients for passive elements of STAR-RIS. The base station can classify terminals into transmission area groups or reflection area groups and determine control values ​​for STAR-RIS using the classified status of the terminals.

[0248] Below, a procedure for determining control information for controlling STAR-RIS is described. The control information for controlling STAR-RIS can be determined based on a transmission rate for a transmission area group and a transmission rate for a reflection area group.

[0249] FIG. 16 illustrates an example of a procedure by which a base station determines control values ​​for STAR-RIS based on channel estimation according to one embodiment of the present disclosure. Referring to FIG. 16 , based on channel measurements, the base station can determine control signals to be transmitted to a terminal and component values ​​for controlling STAR-RIS.

[0250] Referring to FIG. 16, in step S1601, the base station acquires channel information. A channel measurement procedure may be performed to acquire the channel information. For example, channel measurement may be performed by the base station or the terminal based on a reference signal, such as in steps S1407 and / or S1507. The channel information may include information regarding the strength (or size) of the measured channel. For example, the channel information may include the RSRP (received signal received power) value of the reference signal determined through the channel measurement procedure.

[0251] In step S1603, the base station determines the group to which each terminal will be included based on channel information. The group to which each terminal will be included can be determined as either a transmission area group or a reflection area group, and can be determined based on the RSRP acquired by the base station. For example, if the measured RSRP is greater than a certain threshold, the terminal will be included in the transmission area group, and if the measured RSRP is less than a certain threshold, the terminal will be included in the reflection area group.

[0252] In step S1605, the base station performs scheduling related to STAR-RIS. The base station can determine transmission coefficients, reflection coefficients, and power allocated to subcarriers for the passive elements of STAR-RIS, the terminals supported in each subcarrier for scheduling data transmission and / or reception. Here, the transmission coefficients and reflection coefficients can be determined based on transmission rates for the terminals. For example, the base station can assign the subcarriers allocated to each terminal to the passive elements of STAR-RIS, and the base station can determine the transmission coefficients and reflection coefficients for the passive elements of STAR-RIS based on the transmission rate for the transmission area group and the transmission rate for the reflection area group.

[0253] In step S1607, the base station controls STAR-RIS. The base station can generate control information for controlling STAR-RIS based on the determined transmission coefficient and reflection coefficient. The control information can include values ​​of transmission coefficient and reflection coefficient. If pairs of transmission coefficient and reflection coefficient supported by STAR-RIS are determined, the transmission coefficient and reflection coefficient can be indicated as index values ​​using a table. The index values ​​corresponding to the transmission coefficient and reflection coefficient determined in step S1605 can be included. The base station can transmit control information for passive elements to STAR-RIS and control STAR-RIS.

[0254] In step S1609, the base station transmits and / or receives data signals to and from terminals. The base station can transmit and / or receive data signals to and from terminals in the transmission area and terminals in the reflection area via STAR-RIS.

[0255] Because the base station must determine both the transmission and reflection coefficients of STAR-RIS, high complexity may be required to optimize the transmission and reflection coefficients. Below, a method for maximizing the aggregate transmission rate with low complexity in a multi-user multiple-input multiple-output (MIMO-OFDM) system is described.

[0256] FIG. 17 illustrates an example of a procedure for a base station to control STAR-RIS for downlink signals according to one embodiment of the present disclosure. Referring to FIG. 17 , the base station can determine parameter values ​​for controlling STAR-RIS. Before performing the procedures of FIG. 17 , it is assumed that the base station has classified each of a plurality of terminals into a transmission area group or a reflection area group.

[0257] Referring to Figure 17, in step S1701, the base station determines which terminals are supported on each subcarrier. To maximize the aggregate transmission rate, the nth subcarrier is assigned to the terminal with the highest channel gain for that subcarrier. The assignment of the nth subcarrier to the kth terminal can be expressed as in [Mathematical Formula 7] below.

[0258]

[0259] In [Mathematical Formula 7], k represents the terminal index value to which the nth subcarrier is allocated, means the k'th channel for the nth subcarrier in [Mathematical Formula 4].

[0260] According to [Mathematical Formula 7], the base station can assign each of the multiple subcarriers to the terminal with the highest channel gain among the multiple terminals. Once the subcarriers are assigned, the power of the kth terminal in the nth subcarrier can be defined as in [Mathematical Formula 8] below.

[0261]

[0262] In [Equation 8], means the power of the nth subcarrier, Satisfies. refers to the set of subcarrier indices assigned to the kth terminal, Satisfies.

[0263] The base station can assign each subcarrier to each terminal with the highest transmission rate using [Mathematical Equation 7] and [Mathematical Equation 8].

[0264] In step S1703, the base station determines the subcarrier corresponding to the STAR-RIS element. In a communication environment using STAR-RIS rather than RIS, the base station can allocate one subcarrier corresponding to a terminal included in a transmission area group and one subcarrier corresponding to a terminal included in a reflection area group to each element to utilize the characteristic of STAR-RIS that can simultaneously transmit and reflect an incident signal. The following describes a specific procedure for determining a STAR-RIS passive element corresponding to a subcarrier.

[0265] In the following, it is assumed that the magnitude of the transmission coefficient and the magnitude of the reflection coefficient of STAR-RIS are fixed. The phase of the transmission coefficient and the phase of the reflection coefficient for any STAR-RIS passive element can be independently controlled. Therefore, in order to maximize the overall sum-throughput, the STAR-RIS passive element corresponding to the subcarrier can be determined so that the sum-throughput of each area is maximized by separating the groups of transmission regions and the groups of reflection regions.

[0266] First, the base station can determine the STAR-RIS passive element corresponding to the subcarrier of the transmission area. For convenience of explanation, the passive element of the mth STAR-RIS is Assume that the th subcarrier is allocated. Since one terminal is supported in each subcarrier, Maximizing the transmission rate of the th subcarrier is It is equivalent to maximizing the channel gain of the th subcarrier. The phase of the transmission coefficient of the m-th passive element that can maximize the channel gain of the th subcarrier can be determined as shown in [Mathematical Formula 9] below.

[0267]

[0268] In [Equation 9], means the i-th element of the transmission coefficient, Is The i-th element of , Is It means the i-th column.

[0269] The mth passive element When assigned to the th subcarrier, the transmission coefficient can be expressed as in [Mathematical Formula 10] below.

[0270]

[0271] In the passive element allocation process of STAR-RIS, the base station assigns the m-th passive element to a specific subcarrier to maximize the aggregate transmission rate of the transmission area group. In order to maximize the aggregate transmission rate of the transmission area group, the m-th passive element is assigned to a subcarrier that can obtain the largest aggregate transmission rate of the transmission area group when the phase coefficient is set to maximize the channel gain of each subcarrier among the subcarriers of the terminals existing in the transmission area group. Subcarrier assigned to the m-th passive element can be expressed as in [Mathematical Formula 11] below.

[0272]

[0273] In [Equation 11], is the mth passive element It refers to the frequency domain channel of the nth subcarrier when assigned to the nth subcarrier. can be expressed as in [Mathematical Formula 12] below.

[0274]

[0275] The passive element allocation in the reflection domain group can be performed in the same manner as the passive element allocation procedure in the transmission domain group. For convenience of explanation, the passive element of the mth STAR-RIS is Assume that the th subcarrier is assigned to the th subcarrier. That is, The phase of the reflection coefficient of the m-th passive element that can maximize the channel gain of the th subcarrier can be determined as shown in [Mathematical Formula 13] below.

[0276]

[0277] In [Equation 13], means the i-th element of the reflection coefficient, Is The i-th element of , Is It means the i-th column.

[0278] The mth passive element When assigned to the th subcarrier, the reflection coefficient can be expressed as in [Mathematical Formula 14] below.

[0279]

[0280] In the passive element allocation process of STAR-RIS, the base station assigns the m-th passive element to a specific subcarrier to maximize the sum transmission rate of the reflection area group. In order to maximize the sum transmission rate of the reflection area group, the m-th passive element is assigned to a subcarrier that can obtain the largest sum transmission rate of the reflection area group when the phase coefficient is set to maximize the channel gain of each subcarrier among the subcarriers of the terminals existing in the reflection area group. Subcarrier assigned to the m-th passive element can be expressed as in [Mathematical Formula 15] below.

[0281]

[0282] In [Equation 15], is the mth passive element It refers to the frequency domain channel of the nth subcarrier when assigned to the nth subcarrier. can be expressed as in [Mathematical Formula 16] below.

[0283]

[0284] That is, the base station uses [Equation 11] to assign the subcarrier to the m-th passive element based on the transmission rate of the transmission area group. , and the subcarrier assigned to the m-th passive element based on the transmission rate of the reflection region group using [Mathematical Formula 15]. can be decided.

[0285] In step S1705, the base station determines the phase of the transmission coefficient and the phase of the reflection coefficient. The phase of the transmission coefficient of STAR-RIS can be determined based on the subcarriers assigned to the transmission area group, and the phase of the reflection coefficient of STAR-RIS can be determined based on the subcarriers assigned to the reflection area group. That is, the base station uses [Mathematical Formula 9] to determine the subcarriers of the transmission area assigned to each passive element (e.g., The phase of the transmission coefficient of the mth element can be determined based on the transmission rate (or channel gain) of the mth subcarrier.

[0286] Additionally, the base station uses [Equation 13] to determine the subcarriers of the reflection area assigned to each passive element (e.g., The phase of the reflection coefficient of the mth element can be determined based on the transmission rate (or channel gain) of the mth subcarrier.

[0287] To determine the overall passive element allocation and phase in a transmission area group, the base station sequentially determines the passive element allocation and phase coefficients of the passive elements from the first passive element to the last passive element. Similarly, to determine the overall passive element allocation and phase in a reflection area group, the base station sequentially determines the passive element allocation and phase coefficients of the passive elements from the first passive element to the last passive element.

[0288] In step S1707, the base station determines the magnitude of the transmission coefficient and the magnitude of the reflection coefficient. The base station can update the magnitude coefficients based on the phase of the transmission coefficient and the phase coefficient of the reflection coefficient of STAR-RIS. The phase of the transmission coefficient and the phase of the reflection coefficient can be independently controlled, but the magnitude of the transmission coefficient and the magnitude of the reflection coefficient cannot be independently controlled due to the law of conservation of energy. Therefore, through element allocation, the mth element is assigned , The size factors can be updated so that the combined transmission rate considering the transmission rates of the th subcarriers simultaneously is maximized. , The sum of the transmission rate of the th subcarriers can be expressed as in [Mathematical Formula 17] below.

[0289]

[0290] In [Equation 17], and are each and It means the terminal index supported in the th subcarriers, Is It means a constant that can be obtained by expanding [Mathematical Formula 17]. The problem (P1) of maximizing the sum transmission rate of [Mathematical Formula 17] can be expressed as the phase coefficient in [Mathematical Formula 18] below.

[0291]

[0292] In [Equation 18], is. Problem (P1) is the objective function and Due to its complex nature and limitations, it cannot be solved as a closed-form problem. Therefore, the base station can derive a lower bound for the objective function and iteratively optimize until the lower bound converges to maximize the lower bound. The problem of maximizing the lower bound (P2) can be expressed as [Mathematical Equation 19] below.

[0293]

[0294] In [Mathematical Formula 19], v represents the number of iterations, is the lower bound function obtained from the previous iteration procedure. It means the first-order Taylor approximation in [Equation 18]. cast Replace with The solution to (P2) can be obtained by finding the point where the maximum value is (e.g., the point where the derivative becomes 0). Therefore, [Equation 18] can be expressed as a 4th-order equation, which is a differentiated equation, and if the solution where the 4th-order equation becomes 0 is found, the solution to problem (P2) can be obtained in closed form. The solution obtained through the vth iteration and By setting it to , and solving the problem of maximizing the lower bound until convergence, the magnitude coefficients of the m-th element can be obtained. That is, the magnitude of the transmission coefficient and the magnitude of the reflection coefficient of the passive element can be determined based on the change in the sum transmission rate of the subcarriers assigned to each passive element. The base station determines the magnitude of the transmission coefficient and the magnitude of the reflection coefficient of the STAR-RIS passive element in order from the first passive element to the last passive element. In step S1709, the base station determines the power allocated to the subcarriers. The power allocated to the subcarriers can be determined in various ways. The base station can determine the power allocated to the subcarriers based on the water-filling technique.

[0295] The procedures described in FIG. 17 assume that the base station knows the channel between the terminal and the base station, the channel between the terminal and STAR-RIS, and the channel between the base station and STAR-RIS using the channel measurement procedure. Therefore, the frequency domain channel for the subcarrier can be determined using the channel information between the terminal and the base station, the channel between the terminal and STAR-RIS, and the channel information between the base station and STAR-RIS obtained through the channel measurement procedure. [Mathematical Formula 12] and [Mathematical Formula 16] can be used to determine the frequency domain channel. The frequency domain channel for the subcarrier can be used to determine the transmission rate for the transmission region group and the transmission rate for the reflection region group. That is, the base station can determine the transmission rate for the transmission region group and the transmission rate for the reflection region group using [Mathematical Formula 11] and [Mathematical Formula 15] based on the channel measurement result.

[0296] FIG. 18 illustrates an example of an algorithm for optimizing reflection and transmission coefficients for downlink signals according to one embodiment of the present disclosure. Using the algorithm of FIG. 18, a base station can optimize transmission and reflection coefficients by repeatedly performing steps S1703 to S1709.

[0297] Referring to Figure 18, first, the base station initializes the variables. Transmission coefficient and reflection coefficient is initialized randomly, and the power vector p of size n×1 is the maximum transmission power of the base station. can be initialized to be uniformly allocated to each subcarrier. Here, the power vector p is can be expressed as a set of subcarrier indices assigned to the kth terminal. can be set to an empty set.

[0298] First, each subcarrier is assigned to a single terminal. In the first loop, For each STAR-RIS element, a terminal belonging to a group in the transmission region and a terminal belonging to a group in the reflection region are assigned. When two terminals are assigned to the elements, the phase of the transmission coefficient and the phase of the reflection coefficient are updated.

[0299] In the second loop For each of the number of STAR-RIS elements, the size of the transmission coefficient and the size of the reflection coefficient are updated. The size of the transmission coefficient and the size of the light reflection coefficient can be updated by [Mathematical Formula 18]. The iterative sum transmission rate is can be performed until convergence. After that, the base station performs subcarrier allocation, first loop, second loop and power allocation. By performing the iterations, the aggregate transmission rate can be maximized.

[0300] Although the optimization procedure for downlink signals is described in FIGS. 17 and 18, the optimization procedure for uplink signals can be applied in a similar manner. However, in the optimization procedure for uplink signals, the base station can apply an MRC (maximum ratio combiner) beamformer for uplink instead of an MRT beamformer for downlink. In the optimization procedure for uplink signals, step S1709 of FIG. 17 and the power allocation step of FIG. 18 can be omitted.

[0301] The complexity of the technique proposed in this disclosure is , the number of passive components in STAR-RIS. has a linear relationship. Therefore, if STAR-RIS has a large number of elements, Compared to other convex optimization-based techniques with the above complexity, the control values ​​of the passive components of STAR-RIS can be determined with lower complexity.

[0302] Figure 19 illustrates an example of a timing diagram according to an embodiment of the present disclosure. The base station may assume that channels do not change within a specific correlation time. Referring to Figure 19, represents the coherence time, and it can be assumed that the channel between the base station and the terminal, the channel between the base station and STAR-RIS, and the channel between STAR-RIS and the terminal do not change during the time interval. If the base station and the terminal perform time division duplex communication, During this time, the base station receives a pilot signal from the terminal and estimates the uplink channel. For channel estimation, the measurement procedure using the reference signal described above in step S1407 and / or step S1507 may be used. For example, the base station may estimate the uplink channel and determine whether the terminals belong to a transmission area group or a reflection area group. In time division duplex communication, the estimated uplink channel information may be utilized based on the channel reciprocity of the uplink and downlink. During this time, the base station can transmit downlink data to the terminal.

[0303] In addition, the base station can optimize the transmission coefficient and reflection coefficient of STAR-RIS using the algorithm of FIG. 18 based on information related to the estimated channel. At this time, the base station can assume that the channel between the base station and the terminal, the channel between the base station and STAR-RIS, and the channel between STAR-RIS and the terminal do not change during the coherence time period. Therefore, the base station can maintain information about the corresponding channels during the coherence time period and optimize the transmission coefficient and reflection coefficient of STAR-RIS.

[0304] FIG. 20 illustrates an example of signaling for transmitting and / or receiving a data signal in a communication environment in which STAR-RIS (2020) according to one embodiment of the present disclosure is utilized. In FIG. 20 , for convenience of explanation, it is assumed that the first terminal (2030) transmits a reference signal. However, this does not necessarily mean that the first terminal (2030) must transmit the reference signal. Accordingly, the procedure may be replaced with one in which the base station (2010) transmits the reference signal to the terminal, and the terminal transmits information related to the measurement results of the reference signal received from the base station (2010).

[0305] Referring to FIG. 20, in steps S2001 and S2003, the base station (2010) transmits a reference signal request message to the first terminal (2030), and the first terminal (2030) transmits a reference signal to the base station (2010). At this time, in order to estimate all of the channels between the base station (2010) and the first terminal (2030), the channels between the base station (2010) and STAR-RIS (2020), and the channels between STAR-RIS (2020) and the first terminal (2030), steps S2001 and S2003 may be repeatedly performed by changing the passive component control values ​​of STAR-RIS.

[0306] In step S2005, the base station (2010) estimates an uplink channel based on a reference signal received from the first terminal (2030). The base station (2010) can determine whether the first terminal (2030) is in a transmission area or a reflection area, and can include the first terminal (2030) in a transmission area group or a reflection area group.

[0307] By leveraging the characteristics of channel reciprocity in TDD situations, uplink channel information can be directly used for downlink data transmission. Based on the estimated channel information, the base station (2010) can allocate at least one subcarrier to the first terminal (2030) and calculate the transmission coefficient and reflection coefficient of STAR-RIS (2020) and the transmission power of each subcarrier.

[0308] In step S2007, the first terminal (2030) transmits and / or receives a data signal to the base station (2010). The first terminal (2030) can receive resource allocation information from the base station (2010). The base station (2010) can determine the setting value of the STAR-RIS element based on channel measurement and transmit and / or receive downlink data from the terminal.

[0309] FIG. 21 illustrates an example of signaling for terminals included in different areas to transmit and / or receive data signals using STAR-RIS (2120) in one embodiment of the present disclosure. Referring to FIG. 21, data signals may be transmitted and / or received based on the first terminal (2130) being included in a transmission area group and the second terminal (2140) being included in a reflection area group.

[0310] Referring to FIG. 21, in step S2101, a base station (2110), STAR-RIS (2120), a first terminal (2130), and a second terminal (2140) perform a channel measurement procedure. In the channel measurement procedure, a channel between the base station (2110) and terminals (2130, 2140), a channel between the base station (2110) and STAR-RIS (2120), and a channel between STAR-RIS (2120) and terminals (2130, 2140) can be measured. For channel measurement, the on-off of STAR-RIS (2120) can be controlled by the base station (2110). For example, the base station can control STAR-RIS to operate in an off state and measure the channel between the channels between the base station (2110) and terminals (2130, 2140).

[0311] In step S2103, the base station (2110) determines a group to which the first terminal (2130) and the second terminal (2140) will be included. The base station (2110) may perform grouping such that the first terminal (2130) is determined to be included in the transmission area based on channel measurement results, and the second terminal (2140) is determined to be included in the reflection area.

[0312] In step S2105, the base station (2110) generates configuration information regarding the terminals (2130, 2140) and the STAR-RIS (2120). The base station (2110) may generate the configuration information based on channel measurement and grouping. The configuration information may include at least one subcarrier to be allocated to the first terminal (2130), at least one subcarrier to be allocated to the second terminal (2140), or coefficient values ​​of a passive element for controlling the STAR-RIS (2120). The base station (2110) may allocate a subcarrier to each of the passive elements of the STAR-RIS (2120). At this time, a subcarrier allocated to the first terminal (2130) and a subcarrier allocated to the second terminal (2140) may be simultaneously allocated to one passive element included in the STAR-RIS (2120). The coefficient values ​​of the passive elements may include transmission coefficients and reflection coefficients, and may be optimized to maximize the total transmission rate. For this purpose, the algorithm of FIG. 18 may be used.

[0313] In step S2107, the base station (2110) transmits STAR-RIS control information to STAR-RIS (2120). The STAR-RIS control information may include information about transmission coefficients and reflection coefficients. The information about transmission coefficients and reflection coefficients may be indicated in various ways. For example, it may be indicated as an index value using a table. STAR-RIS (2120) may control the phase and magnitude of a signal incident on STAR-RIS (2120) to be reflected and / or transmitted by setting the characteristics of a passive element based on the control information.

[0314] In step S2109, the base station (2110) transmits a first control signal to the first terminal (2130). The first control signal may include information regarding resource allocation for the first terminal (2130) and the base station (2110) to transmit and / or receive a data signal. For example, the first control signal may include information regarding at least one subcarrier to be allocated to the first terminal (2130) determined by the base station (2110) in step S2105.

[0315] In step S2111, the base station (2110) transmits a second control signal to the second terminal (2140). The second control signal may include information regarding resource allocation for the second terminal (2140) and the base station (2110) to transmit and / or receive data signals. For example, the second control signal may include information regarding at least one subcarrier to be allocated to the first terminal (2130) determined by the base station (2110) in step S2105.

[0316] In step S2113, the base station (2110) transmits and / or receives a data signal to and / or from the first terminal (2130). The first terminal (2130) can transmit and / or receive a data signal using at least one subcarrier based on the first control signal.

[0317] In step S2115, the base station (2110) transmits and / or receives a data signal to and / or from the second terminal (2140). The first terminal (2130) may transmit and / or receive a data signal using at least one subcarrier based on the second control signal.

[0318] Below, the performance of the proposed technique is described through specific embodiments of the present disclosure. A base station with a dog antenna Terminals existing in the transmission area group of the dog It is assumed that an environment is established in which communication is performed with terminals existing in a group of reflection areas. STAR-RIS is used at this time. It is assumed that the base station has a uniform linear array structure and STAR-RIS has a uniform planar array structure.

[0319] The time domain channel between the base station and terminals, the time domain channel between the base station and STAR-RIS, and the time domain channel between STAR-RIS and terminals are respectively and , It is assumed that the system has channel taps, and the first channel tap of each channel is modeled as a line of sight (LoS) channel, and the remaining channel taps are modeled as Rayleigh channels. The path loss exponents in large-scale fading are assumed to be 3.8, 2.2, and 2.5 for the channels between the base station and terminals, the base station and STAR-RIS, and the channels between STAR-RIS and terminals, respectively. The power between channel taps is assumed to follow an exponential power delay profile. with subcarriers of the dog An OFDM system with a cyclic prefix (CP) of length 1 is assumed. The maximum transmission power of the base station is In dBm, the noise power spectrum is In dBm, the bandwidth of the entire system is assumed to be 10 MHz.

[0320] To verify the performance of the proposed technique, five techniques are compared. To focus on the impact of STAR-RIS's transmission and reflection coefficients, subcarrier allocation uses the results obtained from the proposed technique, and power allocation between subcarriers uses a water-filling algorithm. The five techniques compared are as follows.

[0321] - Proposed: The technique proposed in this disclosure.

[0322] - SCA: A technique that optimizes transmission and reflection coefficients using the successive convex approximation (SCA) technique.

[0323] - [2]: A technique in which each element of STAR-RIS is assigned to one subcarrier of any terminal included in the transmission area group or reflection area group. A technique updated through the RIS element allocation technique.

[0324] - [5]: A technique in which two RISs are used. One RIS is capable of only transmitting, and the other is capable of only reflecting. Each RIS is It has elements. The coefficients of RIS for each RIS are optimized through the Riemannian conjugate gradient algorithm.

[0325] Random: A technique in which the transmission and reflection coefficients are set to have random phases and magnitudes.

[0326] The results of simulating the sum transmission rate using STAR-RIS with M number of passive elements are as shown in Figs. 22 and 23.

[0327] FIG. 22 illustrates an example of the summation throughput according to the number of passive elements of STAR-RIS according to an embodiment of the present disclosure. It can be seen that the performance of all techniques increases as the number of passive elements of STAR-RIS increases. FIG. 23 illustrates an example of the summation throughput according to the maximum transmission power according to an embodiment of the present disclosure. It can be seen that the performance of all techniques increases linearly with the transmission power. Looking at the summation throughput comparison shown in FIGS. 22 and 23, it can be seen that the proposed technique has superior performance compared to other compared techniques except for the SCA technique. The SCA technique has high complexity because it simultaneously optimizes the phase and magnitude coefficients. However, the proposed technique, which has lower complexity than the SCA technique, can exhibit performance comparable to the SCA technique. And it can be seen that the technique proposed in this disclosure outperforms [2] and [5]. This is because the STAR-RIS elements of [2] and [5] can only transmit or reflect signals, rather than simultaneously transmit and reflect signals, and thus the degrees of freedom (DoF) cannot be fully utilized. This shows that utilizing STAR-RIS can improve the aggregate transmission rate compared to systems utilizing existing RIS.

[0328]

[0329] Below, examples of wireless device utilization to which various embodiments of the present disclosure are applied are described.

[0330] Figure 24 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).

[0331] Referring to FIG. 24, the wireless device (200) corresponds to the wireless device (200) of FIG. 2 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 one or more processors (202) and / or one or more memories (204) of FIG. 2. For example, the transceiver(s) (214) may include one or more transceivers (206) and / or one or more antennas (208) of FIG. 2. 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).

[0332] 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.

[0333] In FIG. 24, 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 one or more elements. For example, the control unit (220) may be composed of a set of one or more processors. For example, the control unit (220) may be composed of a set 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.

[0334] Below, the implementation example of Fig. 24 is described in more detail with reference to the drawings.

[0335] Figure 25 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).

[0336] Referring to FIG. 25, 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. 25 correspond to blocks 210 to 230 / 240 of FIG. 24, respectively.

[0337] 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.

[0338] 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).

[0339] Figure 26 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.

[0340] Referring to FIG. 26, 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. 26 correspond to blocks 210 / 230 / 240 of FIG. 24, respectively.

[0341] 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.

[0342] 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).

[0343] Figure 27 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 27, 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 24, respectively.

[0344] 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.

[0345] 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).

[0346] Figure 28 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.

[0347] Referring to FIG. 28, 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. 28 correspond to blocks 210 to 230 / 240 of FIG. 24, respectively.

[0348] 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.

[0349] 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).

[0350] 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).

[0351] Figure 29 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.

[0352] Referring to FIG. 29, 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. 29 correspond to blocks 210 to 230 / 240 of FIG. 24, respectively.

[0353] 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.

[0354] Figure 30 illustrates an example of an AI device applicable to the present disclosure.

[0355] 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.

[0356] Referring to FIG. 30, 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. 30 correspond to blocks 210 to 230 / 140 of FIG. 24, respectively.

[0357] The communication unit (210) can transmit and receive wired and wireless signals (e.g., sensor information, user input, learning models, control signals, etc.) to and from 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).

[0358] 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 a predicted operation or an operation determined to be desirable among at least one executable operation. 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.

[0359] 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).

[0360] 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.

[0361] 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).

[0362] 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).

[0363] 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.

[0364] 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.

[0365] 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.

[0366] Additionally, embodiments of the present disclosure can be applied to various applications such as autonomous vehicles and drones.

Claims

1. In a method performed by a terminal in a wireless communication system, A step of receiving system information from a base station; A step of performing an initial connection procedure with the base station based on the above system information; A step of receiving setting information regarding channel measurement from the base station; A step of performing a channel measurement procedure based on the above setting information; A step of receiving a control signal from the base station; and A step of transmitting or receiving a data signal to the base station using at least one subcarrier among a plurality of subcarriers based on the control signal, The above data signal is transmitted or received via STAR-RIS (simultaneously transmitting and reflecting reconfigurable intelligent surface), A method in which control information for the passive elements of the above STAR-RIS is determined based on the transmission rate for the transmission area group and the transmission rate for the reflection area group.

2. In paragraph 1, Each of the above plurality of subcarriers is allocated to a terminal with the largest channel gain among the plurality of terminals, A method in which each of the plurality of terminals is included in the transmission area group or the reflection area group.

3. In paragraph 2, A method in which a subcarrier assigned to a terminal included in the above transmission area group and a subcarrier assigned to a terminal included in the above reflection area group are assigned to each of the above passive elements.

4. In paragraph 3, The subcarriers allocated to the terminals included in the above transmission area group are allocated to each of the passive elements based on the transmission rate of the transmission area group, A method in which subcarriers allocated to terminals included in the above reflection area group are allocated to each of the above passive elements based on the transmission rate of the reflection area group.

5. In paragraph 4, Control information for the above passive elements includes information about transmission coefficients and reflection coefficients, The phase of the above transmission coefficient is determined based on the subcarriers allocated to the terminals included in the above transmission area group, A method in which the phase of the above reflection coefficient is determined based on the subcarriers allocated to the terminals included in the above reflection area group.

6. In paragraph 5, A method in which the size of the above transmission coefficient and the size of the above reflection coefficient are determined based on the sum transmission rate of the subcarriers allocated to each of the above passive elements.

7. In paragraph 6, A method in which the power allocated to the above multiple subcarriers is determined based on a water-filling technique.

8. In paragraph 1, Information about a first channel between the terminal and the base station, information about a second channel between the base station and the STAR-RIS, and information about a third channel between the STAR-RIS and the terminal are determined based on the channel measurement procedure, A method in which the transmission rate for the transmission area group and the transmission rate for the reflection area group are determined based on information about the first channel, information about the second channel, and information about the third channel.

9. In paragraph 8, A method in which information about the first channel, information about the second channel, and information about the third channel are maintained during a coherence time period.

10. In a method performed by a base station in a wireless communication system, A step of transmitting system information to a terminal; A step of performing an initial connection procedure with the above terminal; A step of transmitting setting information regarding channel measurement to the terminal; A step of performing a channel measurement procedure based on the above setting information; A step of transmitting a control signal to the terminal; A step of transmitting control information about passive elements to STAR-RIS (simultaneously transmitting and reflecting reconfigurable intelligent surface); and A step of transmitting or receiving a data signal using at least one subcarrier among a plurality of subcarriers from the terminal, The above data signal is transmitted or received through the STAR-RIS, A method in which control information for the above passive elements is determined based on a transmission rate for a transmission area group and a transmission rate for a reflection area group.

11. In paragraph 10, A step of allocating each of the plurality of subcarriers to each of the plurality of terminals; A step of allocating a subcarrier assigned to a terminal included in the transmission area group and a subcarrier assigned to a terminal included in the reflection area group to each of the above passive elements; A step of determining the phase of the transmission coefficient and the phase of the reflection coefficient of the passive elements of the above STAR-RIS; and Further comprising a step of determining the magnitude of the transmission coefficient and the magnitude of the reflection coefficient based on the phase of the transmission coefficient and the phase of the reflection coefficient, A method wherein control information for the above passive elements includes information regarding the transmission coefficient and the reflection coefficient.

12. In paragraph 11, The phase of the above transmission coefficient is determined based on the transmission rate of the above transmission area group, A method in which the phase of the above reflection coefficient is determined based on the transmission rate of the above reflection area group.

13. In paragraph 12, Information about a first channel between the terminal and the base station, information about a second channel between the base station and the STAR-RIS, and information about a third channel between the STAR-RIS and the terminal are determined based on the channel measurement procedure, A method in which the transmission rate for the transmission area group and the transmission rate for the reflection area group are determined based on information about the first channel, information about the second channel, and information about the third channel.

14. In paragraph 13, A method in which the size of the above transmission coefficient and the size of the above reflection coefficient are determined based on the amount of change in the sum transmission rate of the subcarriers allocated to each of the above passive elements.

15. In paragraph 10, The steps for performing the above channel measurement procedure are: A step of transmitting a reference signal request message to the terminal; A step of receiving a reference signal from the terminal; and Including a step of measuring the RSRP (received signal received power) of the above reference signal, A method in which the terminal is included in the transmission area group or the reflection area group based on the RSRP.

16. In paragraph 15, The above channel measurement procedure is performed while the STAR-RIS is off.

17. In a wireless communication system, at a terminal, Transmitter and receiver; and A processor connected to the above transmitter and receiver is included, The above processor, Receive system information from the base station, Perform an initial connection procedure with the base station based on the above system information, Receive setting information regarding channel measurement from the above base station, Perform channel measurement procedure based on the above setting information, Receive a control signal from the above base station, A method of transmitting or receiving a data signal to or from the base station using at least one subcarrier among a plurality of subcarriers based on the control signal, The above data signal is transmitted or received via STAR-RIS (simultaneously transmitting and reflecting reconfigurable intelligent surface), The control information for the passive elements of the above STAR-RIS is determined based on the transmission rate for the transmission area group and the transmission rate for the reflection area group.

18. In a base station in a wireless communication system, Transmitter and receiver; and A processor connected to the above transmitter and receiver is included, The above processor, Transmit system information to the terminal, Perform the initial connection procedure with the above terminal, Transmits setting information regarding channel measurement to the above terminal, Perform channel measurement procedure based on the above setting information, Transmit a control signal to the above terminal, Transmit control information about passive components to STAR-RIS (simultaneously transmitting and reflecting reconfigurable intelligent surface), A device configured to transmit or receive a data signal using at least one subcarrier among a plurality of subcarriers from the terminal, The above data signal is transmitted or received through the STAR-RIS, A base station in which control information for the above passive elements is determined based on the transmission rate for the transmission area group and the transmission rate for the reflection area group.

19. 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, A step of receiving system information from a base station; A step of performing an initial connection procedure with the base station based on the above system information; A step of receiving setting information regarding channel measurement from the base station; A step of performing a channel measurement procedure based on the above setting information; A step of receiving a control signal from the base station; and A step of transmitting or receiving a data signal to the base station using at least one subcarrier among a plurality of subcarriers based on the control signal, The above data signal is transmitted or received via STAR-RIS (simultaneously transmitting and reflecting reconfigurable intelligent surface), A communication device in which control information for the passive elements of the above STAR-RIS is determined based on the transmission rate for the transmission area group and the transmission rate for the reflection area group.

20. 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: Receive system information from the base station, Perform an initial connection procedure with the base station based on the above system information, Receive setting information regarding channel measurement from the above base station, Perform channel measurement procedure based on the above setting information, Receive a control signal from the above base station, A method of transmitting or receiving a data signal to or from the base station using at least one subcarrier among a plurality of subcarriers based on the control signal, The above data signal is transmitted or received via STAR-RIS (simultaneously transmitting and reflecting reconfigurable intelligent surface), A computer-readable recording medium in which control information for the passive elements of the above STAR-RIS is determined based on a transmission rate for a transmission area group and a transmission rate for a reflection area group.