Apparatus and method for performing communication and channel estimation by using multi-functional signal in wireless communication system

Abstract

The purpose of the present disclosure is to perform communication and channel estimation by using a multi-functional signal in a wireless communication system. A method for operating a first device may include the steps of: transmitting a first signal having a non-coherent detectable structure; transmitting first configuration information related to sounding to a second device; receiving a second signal on the basis of the first configuration information; transmitting second configuration information related to channel estimation to the second device; and transmitting a third signal to the second device on the basis of the second configuration information. The second configuration information is based on an antenna position of the second device, the antenna position being estimated on the basis of the first signal and the second signal, and may include a range of at least one basis vector included in a dictionary.

Description

Device and method for performing communication and channel estimation using multi-functional signals in a wireless communication system

[0001] The following description relates to a wireless communication system, and to a device and method for performing communication and channel estimation using a multi-functional signal in a wireless communication system.

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

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

[0004] The present disclosure may provide a device and method for effectively utilizing a multi-functional signal in a wireless communication system.

[0005] The present disclosure may provide a device and method for performing communication, radar sensing, and channel estimation using a single signal in a wireless communication system.

[0006] The present disclosure may provide a device and method for generating channel feedback information without prior knowledge of a signal in a wireless communication system.

[0007] The present disclosure may provide a device and method for generating and transmitting information related to a distance for a transmission signal and channel information in a wireless communication system.

[0008] The present disclosure may provide a device and method for generating and transmitting distance information for a channel based on portions of a signal in a wireless communication system.

[0009] The present disclosure may provide a device and method for designing a constellation for a space-time (ST) waveform in a wireless communication system.

[0010] The present disclosure may provide a device and method for designing a constellation diagram by considering an analog phase array in a wireless communication system.

[0011] The present disclosure may provide a device and method for generating a signal of an ST waveform using an analog phased array in a wireless communication system.

[0012] The present disclosure can provide a device and method for effectively estimating a channel in a near-field environment in a wireless communication system.

[0013] The present disclosure may provide a device and method for providing auxiliary information for channel estimation using a sounding signal in a wireless communication system.

[0014] The present disclosure may provide a device and method for estimating the position of an antenna used to transmit a sounding signal in a wireless communication system.

[0015] 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.

[0016] As an example of the present disclosure, a method of operating a first device in a wireless communication system may include the steps of transmitting a first signal having a non-coherent detectable structure, transmitting first configuration information related to sounding to a second device, receiving a second signal based on the first configuration information, transmitting second configuration information related to channel estimation to the second device, and transmitting a third signal to the second device based on the second configuration information. The second configuration information may be based on an antenna position of the second device estimated based on the first signal and the second signal, and may include a range of at least one basis vector included in a dictionary.

[0017] As an example of the present disclosure, in a wireless communication system, a first device includes a transceiver and a processor connected to the transceiver, wherein the processor controls the first device to transmit a first signal having a non-coherent detectable structure, transmit first configuration information related to sounding to a second device, receive a second signal based on the first configuration information, transmit second configuration information related to channel estimation to the second device, and transmit a third signal to the second device based on the second configuration information, wherein the second configuration information is based on an antenna position of the second device estimated based on the first signal and the second signal, and may include a range of at least one basis vector included in a dictionary.

[0018] As an example of the present disclosure, a communication device includes at least one processor, and at least one computer memory coupled to the at least one processor and storing instructions that, when executed by the at least one processor, direct operations, wherein the operations may include: transmitting a first signal having a non-coherent detectable structure; transmitting first configuration information related to sounding to a second device; receiving a second signal based on the first configuration information; transmitting second configuration information related to channel estimation to the second device; and transmitting a third signal to the second device based on the second configuration information. The second configuration information may be based on an antenna position of the second device estimated based on the first signal and the second signal, and may include a range of at least one basis vector included in a dictionary.

[0019] As an example of the present disclosure, a non-transitory computer-readable medium storing at least one instruction includes at least one instruction executable by a processor, the at least one instruction controlling a first device to transmit a first signal having a non-coherent detectable structure, transmit first configuration information related to sounding to a second device, receive a second signal based on the first configuration information, transmit second configuration information related to channel estimation to the second device, and transmit a third signal to the second device based on the second configuration information, wherein the second configuration information is based on an antenna position of the second device estimated based on the first signal and the second signal, and may include a range of at least one basis vector included in a dictionary.

[0020] 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.

[0021] The following effects may be achieved by embodiments based on the present disclosure.

[0022] According to the present disclosure, various operations can be effectively performed using multi-functional signals.

[0023] 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.

[0024] The accompanying drawings are intended to aid understanding of the present disclosure and may provide embodiments of the present disclosure along with detailed descriptions. 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.

[0025] Figure 1 illustrates an example of a communication system applicable to the present disclosure.

[0026] FIG. 2 illustrates an example of a wireless device applicable to the present disclosure.

[0027] FIG. 3 illustrates a method for processing a transmission signal applicable to the present disclosure.

[0028] Figure 4 illustrates a communication procedure between a terminal and a base station applicable to the present disclosure.

[0029] FIG. 5 illustrates an example of a communication structure that can be provided in a 6G (6th generation) system applicable to the present disclosure.

[0030] Figure 6 illustrates an electromagnetic spectrum applicable to the present disclosure.

[0031] Figure 7 illustrates a THz communication method applicable to the present disclosure.

[0032] FIG. 8 illustrates a THz wireless communication transceiver applicable to the present disclosure.

[0033] FIG. 9 illustrates a THz signal generation method applicable to the present disclosure.

[0034] FIG. 10 illustrates a wireless communication transceiver applicable to the present disclosure.

[0035] Figure 11 illustrates a transmitter structure applicable to the present disclosure.

[0036] Figure 12 illustrates a modulator structure applicable to the present disclosure.

[0037] FIG. 13 illustrates an example of the use of a multi-functional signal in a wireless communication system according to one embodiment of the present disclosure.

[0038] FIG. 14 illustrates an example of a procedure for performing various tasks based on a multi-functional signal in a wireless communication system according to one embodiment of the present disclosure.

[0039] FIG. 15 illustrates an example of a procedure for feeding back channel information using a multi-functional signal in a wireless communication system according to one embodiment of the present disclosure.

[0040] FIG. 16 illustrates an example of a waveform structure according to one embodiment of the present disclosure.

[0041] FIG. 17 illustrates an example of a structure of a sub-waveform according to one embodiment of the present disclosure.

[0042] FIG. 18 illustrates an example of a subspace spanned by sub-waveforms according to one embodiment of the present disclosure.

[0043] FIG. 19 illustrates channel information feedback of a base station and a terminal according to one embodiment of the present disclosure.

[0044] FIG. 20 illustrates an example of a procedure for performing sounding-assisted channel estimation using a multi-functional signal in a wireless communication system according to one embodiment of the present disclosure.

[0045] FIG. 21 illustrates an example of the structure of a neural network for determining an antenna position according to one embodiment of the present disclosure.

[0046] FIG. 22a and FIG. 22b illustrate examples of radiation pattern and antenna position detection results according to one embodiment of the present disclosure.

[0047] FIG. 23 illustrates an example of a constellation space of a signal according to one embodiment of the present disclosure.

[0048] FIG. 24 illustrates an example of a procedure for performing near-field channel estimation according to one embodiment of the present disclosure.

[0049] FIG. 25 illustrates an example of a procedure for assisting near-field channel estimation according to one embodiment of the present disclosure.

[0050] FIG. 26 illustrates an example of a procedure for estimating a channel based on an antenna position according to one embodiment of the present disclosure.

[0051] FIG. 27 illustrates an example of a procedure for providing auxiliary information based on antenna location according to one embodiment of the present disclosure.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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).

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] Additionally, specific terms used in the embodiments of the present disclosure are provided to aid in understanding 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.

[0064] 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).

[0065] 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.

[0066] 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.

[0067] Communication system applicable to the present disclosure

[0068] 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.

[0069] 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.

[0070] Figure 1 illustrates an example of a communication system applied to the present disclosure.

[0071] 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.

[0072] 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).

[0073] 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.

[0074] Devices applicable to the present disclosure

[0075] FIG. 2 illustrates an example of a wireless device applicable to the present disclosure.

[0076] 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).

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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).

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] FIG. 3 illustrates a method for processing a transmission signal applicable to the present disclosure. For example, the transmission signal may be processed by a signal processing circuit. At this time, the signal processing circuit (300) may include a scrambler (310), a modulator (320), a layer mapper (330), a precoder (340), a resource mapper (350), and a signal generator (360). At this time, as an example, the operations / functions of FIG. 3 may be performed in the processor (202) and / or the transceiver (206) of FIG. 2. Furthermore, as an example, the hardware elements of FIG. 3 may be implemented in the processor (202) and / or the transceiver (206) of FIG. 2. As an example, blocks 310 to 360 may be implemented in the processor (202) of FIG. 2. Additionally, blocks 310 to 350 may be implemented in the processor (202) of FIG. 2, and block 360 may be implemented in the transceiver (206) of FIG. 2, and are not limited to the above-described embodiment.

[0091] 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). The wireless signal may be transmitted through various physical channels (e.g., a PUSCH, a PDSCH). Specifically, the codeword can 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 can be modulated into a modulation symbol sequence by a modulator (320). The modulation scheme may include pi / 2-binary phase shift keying (pi / 2-BPSK), m-phase shift keying (m-PSK), m-quadrature amplitude modulation (m-QAM), etc.

[0092] A complex modulation symbol sequence can be mapped to at least one transmission layer by a layer mapper (330). The modulation symbols of each transmission layer can be mapped to 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, where N is the number of antenna ports and M is the number of transmission layers. Here, the precoder (340) can perform precoding after performing transform precoding (e.g., discrete Fourier transform (DFT) transform) on the complex modulation symbols. Additionally, the precoder (340) can perform precoding without performing transform precoding.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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).

[0097] 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 according to the 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. However, the request and provision of the system information may be performed after the random access procedure described below.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] 6G communication systems and core implementation technologies of 6G systems

[0102] 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.

[0103] 6G systems utilizing the THz frequency band have the following goals: i) very high data rates per device, ii) a very large number of connected devices, iii) global connectivity, iv) very low latency, v) reduced energy consumption of battery-free IoT devices, vi) ultra-reliable connectivity, and vii) connected intelligence with machine learning capabilities. The vision of the 6G system can be divided into four aspects: “intelligent connectivity,” “deep connectivity,” “holographic connectivity,” and “ubiquitous connectivity,” and the 6G system can be designed to satisfy the requirements as shown in [Table 1] below.

[0104] Per device peak data rate1 TbpsE2E latency1 msMaximum spectral efficiency100 bps / HzMobility supportup to 1000 km / hrSatellite integrationFullyAIFullyAutonomous vehicleFullyXRFullyHaptic CommunicationFully

[0105] 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.

[0106] Figure 5 illustrates an example of a communication structure that can be provided in a 6G system applicable to the present disclosure. Referring to Figure 5, the 6G system is expected to have 50 times higher simultaneous wireless communication connectivity than the 5G wireless communication system. URLLC, a key feature of 5G, is expected to become an even more important technology in 6G communication by providing an end-to-end delay of less than 1 ms. In this case, the 6G system will have much better volumetric spectral efficiency than the frequently used area spectral efficiency. The 6G system can provide very long battery life and advanced battery technology for energy harvesting, so that mobile devices in the 6G system may not need to be separately charged.

[0107] As core implementation technologies of the 6G system, technologies such as artificial intelligence (AI), THz (terahertz) communication, optical wireless technology, FSO backhaul network, massive MIMO technology, blockchain, 3D networking, quantum communication, unmanned aerial vehicles, cell-free communication, wireless information and energy transfer (WIET), integration of sensing and communication, integration of access backhaul networks, holographic beamforming, big data analysis, and large intelligent surface (LIS) can be adopted.

[0108] THz communication utilizes a spectrum in the frequency band between 0.1 THz and 10 THz with corresponding wavelengths ranging from 0.03 mm to 3 mm, as shown in Fig. 6. THz communication can be implemented as follows.

[0109] 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.

[0110] 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) may 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.

[0111] 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.

[0112] 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

[0113] Fig. 8 illustrates a THz wireless communication transceiver applicable to the present disclosure. Referring to Fig. 8, THz wireless communication can be classified based on the method for generating and receiving THz. The THz generation method can be classified into optical device-based or electronic device-based technology. Here, the method for generating THz using electronic devices includes a method using a semiconductor device such as a resonant tunneling diode (RTD), a method using a local oscillator and a multiplier, a method using a monolithic microwave integrated circuit (MMIC) using a compound semiconductor high electron mobility transistor (HEMT)-based integrated circuit, and a method using a Si-CMOS-based integrated circuit. In the case of Fig. 8, a doubler (tripler, multiplier) is applied to increase the frequency, and it passes through a subharmonic mixer and is radiated by an antenna. Since the THz band forms a high frequency, a doubler is essential. Here, the multiplier is a circuit that provides an output frequency that is N times that of the input, matches it to the desired harmonic frequency, and filters out all remaining frequencies. In addition, beamforming can be implemented by applying an array antenna, etc. to the antenna of Fig. 8. In Fig. 8, IF represents an intermediate frequency, a tripler and a multiplier represent a multiplier, PA represents a power amplifier, LNA represents a low noise amplifier, and PLL represents a phase-locked loop.

[0114] FIG. 9 illustrates a THz signal generation method applicable to the present disclosure. FIG. 10 also illustrates a wireless communication transceiver applicable to the present disclosure. Referring to FIGS. 9 and 10 , 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 can obtain a flat response characteristic over a wide frequency band. For the optical device-based THz signal generation, as illustrated in FIG. 9 , a laser diode, a wideband optical modulator, and an ultra-high-speed photodetector are required. In the case of FIG. 9 , 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. 9, 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. 0, 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.

[0115] Fig. 11 illustrates a transmitter structure applicable to the present disclosure. In addition, Fig. 12 illustrates a modulator structure applicable to the present disclosure. Referring to Figs. 11 and 12, a signal phase, etc. can be changed by passing an optical source of a laser through an optical wave guide. At this time, data is loaded by changing the electrical characteristics through a microwave contact, etc. Accordingly, the optical modulator output is formed as a modulated waveform. An opto-electrical modulator (O / E converter) can generate a THz pulse by optical rectification operation by a nonlinear crystal, photoelectric conversion (O / E conversion) by a photoconductive antenna, emission from a bunch of relativistic electrons, etc. Terahertz pulses (THz pulses) generated in the above manner can have lengths ranging from femtoseconds to picoseconds. The optical / electrical converter (O / E converter) performs down conversion by utilizing the non-linearity of the device.

[0116] Considering the THz spectrum usage, it is likely that THz systems will use multiple contiguous gigahertz bands for fixed or mobile service purposes. Based on the outdoor scenario criteria, the available bandwidth can be classified based on the oxygen attenuation of 10^2 dB / km in the spectrum up to 1 THz. Accordingly, a framework in which the available bandwidth is composed of multiple band chunks can be considered. As an example of the above framework, if the THz pulse length for one carrier is set to 50 ps, ​​the bandwidth (BW) becomes approximately 20 GHz.

[0117] Effective down-conversion from the infrared band to the terahertz band (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 terahertz band (THz band), it is necessary to design an O / E converter with the most ideal non-linearity for transferring to the corresponding terahertz band (THz band). If an O / E converter that is not suitable for the target frequency band is used, errors are likely to occur in the amplitude and phase of the corresponding pulse.

[0118] A terahertz transmission and reception system can be implemented using a single optical-to-electrical converter in a single-carrier system. Depending on the channel environment, an optical-to-electrical converter may be required equal to 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-converted using 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 a plurality of chunks. Each chunk may be composed of at least one component carrier (CC).

[0119] Specific embodiments of the present disclosure

[0120] The present disclosure relates to a technique for performing communication using a multi-functional signal in a wireless communication system. In particular, the present disclosure proposes a technique for performing various operations, such as channel estimation, sensing, and communication, using a single signal.

[0121] 6th generation (6G) wireless communication systems aim to support high mobility, which leads to connectivity for a large number of devices and rapid channel changes. This poses challenges for effective feedback of channel state information (CSI). Meanwhile, one of the key enabling technologies for 6G is integrated sensing and communications (ISAC), which features sensing as a native capability. To improve resource efficiency and reduce collaboration overhead, multi-functional space-time (ST) waveforms that perform both sensing and communication can be used. In addition to sensing and communication, ST waveforms can be utilized to implement precoder feedback.

[0122] An on-the-fly precoder quantization technique has been proposed, which uses each sub-waveform of a multi-function ST waveform as random (uniformly) sampled realizations to estimate the desired precoder. Furthermore, a design algorithm for non-coherent ST communications using analog phase arrays has been proposed.

[0123] Meanwhile, in the 6G era, extremely large-scale arrays require near-field channel estimation. Near-field channel estimation methods utilizing information obtained from sensing via antenna arrays have been proposed. Sensing-assisted near-field channel estimation techniques focus on the area where devices are detected. The aforementioned technologies relate to channel acquisition methods within a sensing framework.

[0124] FIG. 13 illustrates an example of the use of a multi-functional signal in a wireless communication system according to one embodiment of the present disclosure. FIG. 13 illustrates a situation in which three terminals (1311 to 1313) and a base station (1320) perform communication.

[0125] Referring to FIG. 13, a base station (1320) transmits a signal. The signal may be transmitted through multiple beams having narrow beam widths or through a beam having a wide beam width. Accordingly, the signal transmitted from the base station (1320) is transmitted toward multiple terminals and at least one structure. That is, the base station (1320) broadcasts a signal. Here, the signal has a structure that allows detection in a non-coherent manner. For example, the signal may include a symbol based on an ST waveform.

[0126] A signal is transmitted toward a first terminal (1311), a second terminal (1312), and a third terminal (1313). The signal includes information to be transmitted to the second terminal (1312), and the second terminal (1312) can detect the signal in a non-coherent manner and obtain information. In addition, the signal can be used to sense the third terminal (1313). The signal is reflected by the third terminal (1313), which is a sensing target, and is received by the base station (1320), and the base station (1320) can detect the position or direction of the third terminal (1313) based on the reflected signal. In addition, the signal is received by the first terminal (1311), and the first terminal (1311) can use the signal for channel estimation. In this way, the signal transmitted from the base station (1320) has various functions. Specifically, the signal can be used as a pilot signal for channel estimation for the first terminal (1311), as a symbol for performing communication through non-coherent detection for the second terminal (1312), and as a sensing signal for radar operation for the third terminal (1313).

[0127] FIG. 14 illustrates an example of a procedure for performing various tasks based on a multi-functional signal in a wireless communication system according to one embodiment of the present disclosure. FIG. 14 illustrates a procedure in which terminals A (1411), B (1412), and C (1413) perform data communication, far-field channel estimation, and near-field channel estimation, respectively.

[0128] Referring to FIG. 14, in step S1401, the base station (1420) transmits a synchronization signal. For example, the base station (1420) broadcasts the synchronization signals to at least one of terminal A (1411) performing downlink communication, terminal B (1412) performing CSI feedback, and terminal C (1413) performing sounding-assisted channel estimation. Accordingly, terminal A (1411), terminal B (1412), and terminal C (1413) can obtain time and / or frequency synchronization with the base station (1420).

[0129] In step S1403, the base station (1420) transmits a space-time (ST) signal. In other words, the base station (1420) generates and transmits a communication signal for terminal A (1411) using ST modulation. Here, the ST signal is a multi-functional signal, a signal having a structure that allows non-coherent detection, and can occupy at least one time resource and at least one frequency resource. According to one embodiment, the base station (1420) can use a constellation design algorithm designed to generate waveforms in an analog domain in a high-speed environment. Since the ST signal is transmitted through a wireless channel, it can be transmitted for communication between the base station (1420) and terminal A (1411), and at the same time, it can be used as a radar signal for sensing the ambient environment, a pilot for channel estimation, etc.

[0130] In step S1405, terminal A (1411) detects an ST signal. Accordingly, terminal A (1411) can obtain information transmitted through the ST signal. That is, terminal A (1411) performs ST demodulation. Accordingly, terminal A (1411) can obtain information by detecting a sequence of the ST signal and interpreting the detected sequence. According to one embodiment, terminal A (1411) can interpret the ST signal and obtain information based on a constellation design algorithm designed to generate waveforms in an analog domain in a high-speed environment.

[0131] In step S1407, the base station (1420) receives a reflected signal corresponding to the ST signal transmitted in step S1403. The reflected signal is generated when the ST signal reaches terminal C (1413) and is reflected. In step S1409, the base station (1420) performs sensing using the reflected signal. That is, the base station (1420) can detect at least one nearby terminal including terminal C (1413) based on monostatic sensing using the ST signal. Specifically, the base station (1420) can estimate the direction and distance to terminal C (1413) based on the antenna of the base station (1420) based on the ST signal and the reflected signal.

[0132] The ST signal transmitted from the base station (1420) has the property of a unitary matrix and can thus be used for monostatic sensing. The purpose of monostatic sensing is to detect a user cluster including terminal C (1413). Simultaneously, the ST signal can be used to detect nearby terminals before applying a sensing-aided near-field channel estimation technique. Monostatic sensing can detect the presence of targets within the line-of-sight (LoS). Although not illustrated in FIG. 14, the base station (1420) can know where the targets or terminals are located and determine whether the targets belong to the near-field.

[0133] In step S1411, terminal B (1412) performs far-field channel estimation. Terminal B (1412) senses a communication signal (e.g., an ambient signal) for terminal A (1411) and may use the sensed signal for channel information feedback. In one embodiment, terminal B (1412) may calculate a distance metric for each sub-waveform of the ST signal. Here, the distance metric may be fed back to indicate far-field CSI (e.g., a desired precoder).

[0134] In step S1413, terminal B (1412) transmits channel information to base station (1420). The channel information includes information related to distance indicators for each sub-waveform of the ST signal. Base station (1420) receives the information related to distance indicators and can acquire far-field CSI (e.g., desired precoder) for terminal B (1412).

[0135] In addition to the aforementioned data communication and far-field channel feedback, the base station (1420) may utilize the uplink large-scale array to acquire near-field CSI for terminal C (1413) using a sensing-aided near-field channel estimation technique. For this purpose, the ST waveform transmitted in step S1403 may be used to determine the value of the elevation coordinate of terminal C (1413). Here, the elevation coordinate means the position on the axis perpendicular to the antenna plane when setting the vertical axis and horizontal axis in the antenna plane of the base station (1420). Additional information such as rough GPS or power level may further be utilized to identify UEs. In addition, the following operations may be required for sensing-aided near-field channel estimation.

[0136] In step S1415, the base station (1420) transmits a sounding request message to terminal C (1413). For example, sounding configuration information may be transmitted as the sounding request message. According to one embodiment, the base station (1420) may request transmission of another sensing waveform (e.g., a single-shot sensing waveform). In step S1417, terminal C (1413) transmits a sounding signal. In other words, terminal C (1413) may transmit a sounding reference signal. According to one embodiment, terminal C (1413) may transmit a sensing waveform (e.g., a single-shot sensing waveform).

[0137] In step S1419, the base station (1420) estimates the antenna position of terminal C (1413) using the sounding signal. The antenna position can be estimated based on the spatial radiation pattern of the sounding signal. In step S1421, the base station (1420) transmits a channel estimation request message. As the channel estimation request message, configuration information related to channel estimation can be transmitted. According to one embodiment, the channel estimation request message can include an estimation result for the antenna position. That is, the base station (1420) can encode the sensing results (e.g., antenna positions) and transmit them to terminal C (1413).

[0138] In step S1423, the base station (1420) transmits reference signals to terminal C (1413). At this time, if terminals other than terminal C (1413) participate in sensing-assisted short-range channel estimation, the base station (1420) may transmit mutually orthogonal pilots to multiple terminals belonging to a user cluster including terminal C (1413) and other terminals. For example, the reference signals may be transmitted based on configuration information (e.g., resource location, etc.) included in the channel estimation request message transmitted in step S1421.

[0139] In step S1425, terminal C (1413) estimates the near-field channel. Specifically, terminal C (1413) estimates its near-field channel based on the received reference signal. At this time, terminal C (1413) can use information included in the channel estimation request message received in step S1421 (e.g., estimation results for antenna positions). In step S1427, terminal C (1413) transmits channel information to the base station (1420). In other words, terminal C (1413) can feed back channel information reporting the results of channel estimation to the base station (1420).

[0140] In the embodiment described with reference to FIG. 14, it was described that data communication, far-field channel estimation, and near-field channel estimation are each performed by three terminals. However, at least one of data communication, far-field channel estimation, and near-field channel estimation may be performed by multiple terminals. In this case, in FIG. 14, terminal A (1411), terminal B (1412), and terminal C (1413) may be understood as multi-terminals or a terminal cluster.

[0141] FIG. 15 illustrates an example of a procedure for feeding back channel information using a multi-functional signal in a wireless communication system according to one embodiment of the present disclosure. FIG. 15 illustrates in more detail a procedure for estimating a far-field channel.

[0142] Referring to FIG. 15, in step S1501, the base station (1520) transmits an ST signal. In other words, the base station (1520) generates and transmits a signal using ST modulation. The ST signal is a multi-functional signal and is used for far-field channel estimation for terminal B (1512), but can also be used for data communication, radar communication, near-field channel estimation, etc. for other terminals.

[0143] In step S1503, terminal B (1512) determines information related to the distance of each portion of the signal. To this end, terminal B (1512) divides the received ST signal into multiple portions. Each portion forms a matrix. Each element of the matrix is ​​a reception value for a sub-symbol of the signal, which can be understood as a sub-symbol that has passed through the channel. Here, the information related to the distance corresponds to the difference between the portion and the desired precoder, i.e., the eigenspace of the channel. For example, terminal B (1512) can determine the square of the norm for each portion.

[0144] In step S1505, terminal B (1512) transmits distance-related information. To transmit channel information to the base station (1520), terminal B (1512) may transmit distance-related information determined in step S1503. In other words, terminal B (1512) may feed back channel information. Here, the information fed back may not explicitly express channel information, and may include information necessary for the base station (1520) to restore or acquire channel information.

[0145] In step S1507, the base station (1520) determines weights based on distance-related information. The base station (1520) may receive information related to the distance between signal segments and precoders from terminal B (1512), and determine weights for combining based on the distance-related information. For example, the base station (1520) may determine the weight for the segment by normalizing a value included in the distance-related information received from terminal B (1512). Here, the normalization may be performed by dividing the value received as distance-related information by the size of the transmission signal matrix of the segment (e.g., the square of the norm, the product of the matrix and the conjugate transpose of the matrix, etc.). Through this, weights corresponding to the number of signal segments may be determined.

[0146] In step S1509, the base station (1520) combines signal segments using weights. Since the weights are related to the distance between the segment and the precoder, combining segments using weights can be understood as combining segments containing distance information. For example, the base station (1520) can determine, for each segment, the product of the segment's matrix and its conjugate transpose, and weight the results of the multiplication. Through this, the base station (1520) can determine a combination matrix that combines the segments.

[0147] In step S1511, the base station (1520) determines channel information based on the combination. That is, it determines an estimation of channel information based on the combination matrix. In other words, the base station (1520) can reconstruct channel information based on portions of the combined signal using weights. For example, the base station (1520) can determine an eigenspace for the combination matrix and determine at least a portion of the determined eigenspace as channel information. For example, the channel information is determined in the form of a precoder, and the precoder can be estimated as principal eigenvectors of the combination matrix. In this case, the number of selected principal eigenvectors may be equal to the number of receiving antennas of terminal B (1512).

[0148] A procedure for far-field channel estimation is described with reference to FIG. 15. The aforementioned procedure can be combined with any of various procedures performed in a communication system. For example, the aforementioned operations can be combined with an initial access procedure, in which case the ST signal can be understood as a synchronization signal (e.g., a primary synchronization signal or a secondary synchronization signal) or a reference signal. Here, the synchronization signal conveys cell information through non-coherent detection. As another example, the aforementioned operations can be combined with a CSI measurement and reporting procedure, in which case the downlink signal can be understood as a reference signal, the distance feedback can be understood as a CSI reporting message, and configuration information for the reference signal can be signaled in advance.

[0149] An example of a procedure for far-field channel estimation has been described with reference to FIG. 15. Further discussion of far-field channel estimation follows. As described above, channel estimation and feedback can be performed using signals having an ST waveform. Furthermore, signals having an ST waveform can be used for non-coherent communication and sensing. To this end, ST waveforms according to various embodiments can be designed to have the following properties.

[0150] Fig. 16 illustrates an example of a waveform structure according to one embodiment of the present disclosure. Referring to Fig. 16, a signal is transmitted through a plurality of antennas (1602-1 to 1602-N). t ) and is transmitted over T time intervals. That is, the waveform occupies N resources in the spatial domain and T resources in the time domain. The divisions in the time domain form sub-waveforms, and the signal includes L sub-waveforms. The signal of Fig. 16, if expressed in matrix form, is as in Fig. 17.

[0151] Fig. 17 illustrates an example of a structure of a sub-waveform according to one embodiment of the present disclosure. Referring to Fig. 17, a signal X is composed of L sub-waveforms X1 to X L . The time axis length of each sub-waveform is N r , and the spatial axis length is N t Here, N r is the number of receiving antennas, N t is the number of transmitting antennas. The total length of signal X is T, so a signal X of length T can be used for non-coherent communication, and a signal of length N r Each sub-waveform of can be used for channel feedback, i.e. sub-waveforms X1 to X L can be treated as random realizations of the channel precoder, and the overall waveform signal X can be modulated by data bits for communication, and further, the signal X can be used as a sensing signal for detecting surrounding targets. Here, sub-waveforms X1 to X L It spans the given space as shown in Fig. 18.

[0152] Figure 18 illustrates an example of a subspace spanned by sub-waveforms according to one embodiment of the present disclosure. Referring to Figure 18, sub-waveforms X1 to X L encompasses the subspaces of the Grassmann manifold. The sub-waveforms X1 through X L can be used as a random realization of channel precoders.

[0153] The waveform according to various embodiments may have the characteristics as described with reference to FIGS. 16 to 18. As described above, X is N t ×T is a matrix of size XX, the rows of signal X are orthogonal to each other, and XX H =I Ntis. In addition, the subspace spanned by X can be used as a constellation point in the Grassmann manifold, and the constellation points can embed data bits for information delivery. In addition, in order to maximize the channel capacity and optimize the channel feedback performance, X can be isotropically distributed. That is, Q H Q=QQ H =I T For all Q satisfying , prob(X)=prob(XQ), and P H P=I Nt For all P satisfying , prob(X)=prob(PX). Furthermore, for optimal sensing resolution and non-coherent channel capacity, the rows of signal X can be orthogonal and isotropically distributed.

[0154] Figure 19 illustrates channel information feedback between a base station and a terminal according to an embodiment of the present disclosure. Figure 19 shows channel information feedback and reconstruction between a terminal (1910) and a base station (1920). Referring to Figure 19, the base station (1920) transmits a signal of a waveform according to an embodiment. Here, since the signal includes a plurality of sub-waveforms, the transmission of the signal can be understood as streaming of the sub-waveforms. Accordingly, the terminal (1910) transmits distance information. is transmitted. Distance information for the th sub-waveform Upon receiving this, the feedback normalization block (1922) normalizes the received distance information, the global update block (1924) weights and adds products of sub-waveforms and conjugate transposes of the sub-waveforms based on the normalized distance information, and the precoder estimation block (1926) determines a precoder based on the result of the weighted addition. The precoding block (1928) performs precoding on the transmitted signal based on the estimated precoder.

[0155] In one embodiment, the distance information being fed back contains a scalar value evaluating how close the detected ST waveform's sub-waveforms are to the desired channel precoder. Specifically, the distance information Is The terminal (1910) may include a norm value of the reception signal matrix for the th sub-waveform. By using the norm value, the terminal (1910) does not need prior information about the ST waveform and may not be burdened with a high amount of computation. The distance information may be referred to as a distance value, a distance index, a distance parameter, or other terms having an equivalent technical meaning.

[0156] The mathematical basis for feedback on values ​​related to the channel is as follows: The results of the singular value decomposition (SVD) for can be expressed as , and the optimal linear eigenmode precoder is the right eigenspace is given as . Here, can be treated as a point on the Grassmann manifold. Accordingly, the terminal (1910) is a base station (1920). Feedback on the indicators needed to estimate .

[0157] Estimated from base station (1910) is used as a desired precoder. of The subspace distance can provide a natural and tractable measure of estimation error. Therefore, and The mean square subspace distance (MSSD) can be used as a performance indicator. Here, The value related to the norm of the th sub-waveform can be expressed as in [Mathematical Formula 1] below.

[0158]

[0159] In [Equation 1], silver The value related to the norm of the th sub-waveform, silver The received signal matrix of the th sub-waveform, is a channel, silver The transmission signal matrix of the th sub-waveform, silver It refers to the noise added to the second sub-waveform.

[0160] Here, Is and Approximate the inter-subspace distance. Accordingly, the terminal (1910) The sequence is transmitted to the base station (1920) as a distance indicator.

[0161] When the distance indicator is fed back, the base station (1920) normalizes the distance indicator and performs a global update. Received feedback information About, the base station (1920) is known Normalization can be performed based on the following equation (2). For example, the base station (1920) can perform normalization as shown in [Mathematical Formula 2] below.

[0162]

[0163] In [Equation 2], silver The value related to the norm of the th sub-waveform, is the value related to the normalized nominal, silver It means the transmission signal matrix of the th sub-waveform.

[0164] By normalizing as in [Equation 2], the effect of different sizes of sub-waveforms can be eliminated. Normalized information is used as a weight to combine all sub-waveforms. Normalized information Combining sub-waveforms based on can be performed as shown in [Mathematical Formula 3] below.

[0165]

[0166] In [Equation 3], is a combination of sub-waveforms, silver The value related to the normalized norm of the th sub-waveform, silver It means the transmission signal matrix of the th sub-waveform.

[0167] Based on the combination of sub-waveforms determined as described above, i.e., the weighted sum of the sub-waveforms, the base station (1920) can determine the precoder. According to one embodiment, the base station (1920) can determine the eigenspace (e.g., N) for the combination of sub-waveforms. rdimensional eigenspace) can be determined as a precoder or an estimate for the precoder. Geometrically, the precoder on the estimated Grassmann manifold is a sub-waveform can be calculated as the weighted centroid of the strongest weight. will be more aligned to sub-waveforms having a smaller sub-space distance or sub-waveforms having a smaller sub-space distance.

[0168] The aforementioned channel information feedback and restoration procedures can be summarized as shown in [Table 3] below.

[0169] To compute the precoder for the channel , initialize = 1, = 0, and repeats:Step 1: The UE computes the distance metric for as ;Step 2: The BS receives and normalizes it as ;Step 3: The BS updates the combination matrix as , ;Until .The BS estimates the precoder as the N r -dimensional principal eigenspace of .

[0170] FIG. 20 illustrates an example of a procedure for performing sounding-assisted channel estimation using a multi-functional signal in a wireless communication system according to an embodiment of the present disclosure. FIG. 20 illustrates the procedure for estimating a near-field channel in more detail.

[0171] Referring to FIG. 20, in step S2001, terminals (2013-1 to 2013-3) and a base station (2020) perform an initialization operation. According to one embodiment, terminals (2013-1 to 2013-3) and a base station (2020) may exchange capability information for channel estimation and allocate resources for subsequent signal transmission. Furthermore, according to one embodiment, during the initialization operation, terminals (2013-1 to 2013-3) may perform synchronization with at least one other terminal for transmitting sounding signals.

[0172] In step S2003, the terminals (2013-1 to 2013-3) transmit sounding signals. The sounding signals are transmitted to sense the antenna positions of the terminals (2013-1 to 2013-3). The sounding signals may be referred to as sounding reference signals, multi-tone waveforms, sensing waveform signals, or other terms having equivalent technical meanings.

[0173] In step S2005, the base station (2020) performs sensing and determines at least one parameter to assist channel estimation. Here, sensing is an operation to estimate the antenna positions of terminals (2013-1 to 2013-3), and the at least one parameter is information to assist channel estimation of the terminals (2013-1 to 2013-3). That is, the base station (2020) estimates the antenna positions of the terminals (2013-1 to 2013-3) based on a set of received signals. In addition, the base station (2020) can encode the sensing result into a vector and broadcast the encoded information as a parameter for channel estimation to a plurality of terminals including the terminals (2013-1 to 2013-3).

[0174] According to one embodiment, the base station (2020) may generate information related to the radiation pattern of a signal. Here, the information related to the radiation pattern may take the form of an image, and the signal includes sounding signals transmitted from terminals (2010-1 to 2010-3). The image represents the antenna positions of each terminal (2010-1 to 2010-3) observed from a reference point of the array of the base station (2020). According to various embodiments, the base station (2020) may generate an image representing the radiation pattern by performing an FFT operation, filtering, and an IFFT operation on the received values ​​of the signal. Then, the base station (2020) may estimate the antenna position based on the radiation pattern. In other words, the base station (2020) may estimate the antenna position based on the image representing the radiation pattern. To this end, the base station (2020) may utilize a neural network model. For example, the neural network model may have a structure as illustrated in FIG. 15 . Through this, the base station (2020) can obtain at least one of angle information and observed size information of the antennas of the terminals (2010-1 to 2010-3) with respect to a reference point on the antenna array of the base station (2020) as information related to the position of the antenna. Then, the base station (2020) generates auxiliary information including information related to the antenna position. The information related to the antenna position is angle information for the antennas of the terminals (2010-1 to 2010-3), and can include at least one of a maximum value of the angle, a minimum value of the angle, and a size of a candidate area for the antenna position (e.g., the number of pixels of a radiation pattern image).

[0175] In step S2007, the base station (2020) transmits parameters for channel estimation. In other words, the base station (2020) transmits configuration information including parameters for channel estimation. Here, the parameters include at least one parameter determined in step S2005. According to one embodiment, the parameters for channel estimation are angle information for each antenna of the terminals (2013-1 to 2013-3) in the antenna array of the base station (2020), and may include at least one of a maximum value of the angle, a minimum value of the angle, and a size of a candidate area for an antenna position (e.g., the number of pixels of a radiation pattern image).

[0176] Parameters for channel estimation may include configuration information related to channel estimation. Each of the terminals (2013-1 to 2013-3) may determine a dictionary search range based on the configuration information. In other words, each of the terminals (2013-1 to 2013-3) may generate a region-focusing dictionary based on an omnidirectional dictionary. According to various embodiments, each of the terminals (2013-1 to 2013-3) may generate a region-focusing dictionary based on configuration information based on antenna locations and the distance between antennas of the base station (2020). Specifically, each of the terminals (2013-1 to 2013-3) can generate a region-focused dictionary based on at least one of an angle vector including angle values ​​falling within a range of maximum and minimum angle values, distance samples corresponding to each of the angle values, and distances between antennas of the base station (2020).

[0177] In step S2009, the base station (2020) transmits pilot signals. In other words, the base station (2020) can transmit mutually orthogonal pilot signals to a plurality of terminals, including terminals (2013-1 to 2013-3). The pilot signals may be referred to as reference signals, CSI-RS, etc.

[0178] In steps S2011 to S2015, each of the terminals (2013-1 to 2013-3) estimates a channel. The terminals (2013-1 to 2013-3) can estimate the channel based on at least one of the parameters for channel estimation and the received pilot signals. That is, the terminals (2013-1 to 2013-3) determine channel information within a search range determined based on the parameters received in step S2007. In other words, the terminals (2013-1 to 2013-3) determine channel information by estimating the channel based on a region-intensive dictionary. According to various embodiments, each of the terminals (2013-1 to 2013-3) can estimate the channel by checking at least one column corresponding to a non-zero element of a sparse matrix among the columns of the region-intensive dictionary. Here, the sparse matrix is ​​a matrix representing the estimated channel. Specifically, the terminals (2013-1 to 2013-3) can identify at least one column corresponding to a non-zero element based on repeated operations of sequentially removing elements corresponding to columns of a specific index of a region-focused dictionary from a matrix containing received values ​​of pilot signals. For example, the terminals (2013-1 to 2013-3) can estimate a channel based on an orthogonal matching pursuit (OMP) technique.

[0179] As described with reference to FIG. 20, sounding-aided channel estimation can be performed. In the aforementioned procedure, the antenna position can be estimated using a radiation pattern generated based on the sounding signal. At this time, the antenna position of the terminal on a two-dimensional plane corresponding to the plane of the base station antenna is estimated. Additionally, distance information between the base station antenna and the terminal antenna may be further required, in which case the distance information can be obtained by radar operation using an ST signal. For example, the radar operation can be understood as the sensing operation performed in step S1409 of FIG. 14.

[0180] An example of a procedure for near-field channel estimation has been described with reference to Figure 20. Further discussion of near-field channel estimation follows. The near-field channel estimation technique according to various embodiments may be referred to as the sounding-assisted OMP (SAOMP) technique. The framework of the SAOMP technique according to various embodiments is as follows.

[0181] SAOMP Protocol: Channel estimation according to various embodiments follows a two-phase protocol for near-field channel estimation. The first phase, channel sounding, utilizes a multi-tone waveform shared by devices without orthogonality between devices. This enables resource-efficient sensing for many devices. The transmitted results of the multi-tone waveform are encoded in a region-focusing dictionary. In the second phase, orthogonal pilots are used for each device, and SAOMP using the region-focusing dictionary is performed to compute an estimated channel.

[0182] Reconstruction of radiation patterns and antenna selection for channel sounding: An algorithm is used to reconstruct radiation patterns. A series of operations, including Fourier transform, filtering, interpolation, and inverse Fourier transform, can be performed to obtain radiation patterns from received signals. Here, filtering can be performed to focus the imaging plane onto the plane where the targets are located. The magnitude of each pixel in the radiation pattern represents the estimated channel gain for a point in three-dimensional space. Here, the magnitude can be expressed by color or saturation. Additionally, a deep learning-based antenna detection algorithm can be used. The antenna detection algorithm can be built upon a semantic-segmentation neural network, thereby enabling rapid antenna detection based on the reconstructed radiation patterns.

[0183] SAOMP: Based on the estimated antenna locations of the devices, a dictionary to be used in SAOMP can be determined. Angular samples from the antenna locations of the devices are used to form a dictionary, which is different from an omnidirectional dictionary, according to various embodiments. This concentrated dictionary allows SAOMP to achieve a level of channel estimation accuracy comparable to that of OMP, even with fewer pilots.

[0184] According to various embodiments, terminals performing near-field channel estimation transmit sounding signals to a base station. The sounding signals transmitted from the terminals are transmitted non-orthogonally, so that the base station receives the sounding signals in an overlapping manner. The base station A planar antenna array including multiple receiving antennas is provided. M terminals are present within the near-field region. Each terminal may have a single antenna or multiple antennas, but for convenience of explanation, it is assumed below that each terminal has a single antenna. In this case, the channel between the base station and the terminals can be expressed as in [Mathematical Formula 4] below.

[0185]

[0186] In [Equation 4], is the near-field channel between the base station antenna n and the terminal antenna m at frequency f, is the attenuation factor, is the signal frequency, means the distance between the base station antenna n and the mth terminal antenna m.

[0187] Here, the distance between the base station antenna n and the terminal antenna m can be defined as in [Mathematical Formula 5] below.

[0188]

[0189] In [Equation 5], is the distance between the base station antenna n and the terminal antenna m, is the x-axis coordinate of the terminal antenna m, is the y-axis coordinate of the terminal antenna m, is the z-axis coordinate of the terminal antenna m, is the x-axis coordinate of the base station antenna n, is the y-axis coordinate of the terminal antenna m, is the location information of the terminal antenna m, means the location information of base station antenna n.

[0190] In the near-field region, the channel gain from the terminal to the base station antennas can be considered uniform. In other words, the channel attenuation from the terminal to the base station antennas can be considered to not vary depending on the base station antenna. Therefore, as in [Mathematical Equation 4], the phase of the channel between the terminal and the base station antennas depends only on the position and / or distance. Here, since the positions of the base station antennas are fixed and known, an estimation of the position of the terminal antenna is required.

[0191] Additionally, the normalized mean squared error (NMSE) can be used as an indicator for evaluating channel sounding performance. For example, NMSE can be defined as in [Mathematical Formula 6] below.

[0192]

[0193] In [Equation 6], is the near-field channel between the base station antenna n and the terminal antenna m at frequency f, Is It means the estimation of .

[0194] A sounding-aided channel estimation technique according to various embodiments may be comprised of two phases, for example, a channel sounding phase and a channel estimation phase. In the channel sounding phase, devices are synchronized to transmit the same multi-tone signal. Here, synchronization may be performed through a timing sequence. Upon successful synchronization with negligible error, the base station can receive the superposed multi-tone signal and estimate the positions of terminals based on the received signal. In the subsequent channel estimation phase, the estimated positions may be encoded as SAOMP parameters so that the terminals can estimate the channel based on orthogonal pilots transmitted by the base station.

[0195] The signal received in an overlapping manner from terminals can be defined as in [Mathematical Formula 7] below.

[0196]

[0197] In [Equation 7], is a sensing signal, is the number of tones included in the sensing signal, silver It means the second tone.

[0198] Referring to [Mathematical Formula 7], adjacent tones have a common gap It is separated using . The total bandwidth consumed by the tones of the dog is can be expressed as a signal For the time-domain implementation, frequency-modulation continuous waveform (FMCW) and / or stepped-frequency continuous waveform (SFCW) can be used.

[0199] The sensing waveform signal at the nth antenna of the base station The received signal of the nth tone is a superposition of the single-tone signals of each of the multiple terminals. The superposition at the nth antenna The reception signal of the th tone can be expressed as follows [Mathematical Formula 8].

[0200]

[0201] In [Equation 8], is received at base station antenna n. The received signal of the th tone, is the attenuation factor for the mth terminal, silver th tone, represents the distance between the base station antenna n and the mth terminal antenna m. Since the signal to noise ratio (SNR) for LoS channels is typically high, channel noise is omitted.

[0202] According to various embodiments, channel sounding may be based on scalar diffraction, which is applicable to millimeter-wave imaging and vehicle sensing. To this end, a function that maps the coordinates of a point in space to the channel gain from the AP to that point may be defined as shown in Equation 9 below.

[0203]

[0204] In [Equation 9], is a function that maps points to channel gain, is the attenuation factor for the mth terminal, refers to a set of coordinates of antennas of terminals.

[0205] Scalar diffraction is An arbitrary exponential term within This allows for the expression of terms of integrals parameterized by .

[0206]

[0207] In [Equation 10], silver th tone, is the distance between the base station antenna n and the mth terminal antenna m, silver , silver , is the x-axis coordinate of the base station antenna n, means the x-axis coordinate of the terminal antenna m.

[0208] By substituting [Mathematical Equation 10] into [Mathematical Equation 8] and using integration within a three-dimensional space to replace the sum between the device antennas, the signal received by the array of the base station can be expressed as in [Mathematical Equation 11] below.

[0209]

[0210] In [Equation 11], is the x-axis position, is the y-axis position, silver th tone, is located ( , )at The reception value of the th tone, is a function that maps points to channel gain, silver , silver , is the x-axis coordinate of the base station antenna n, is the x-axis coordinate of the terminal antenna m, stands for Fourier transform. The subscripts and superscripts indicate dimensionality and direction (e.g., absent for forward, -1 for reverse).

[0211] By inverting [Equation 11], a relationship as shown in [Equation 12] is obtained.

[0212]

[0213] In [Equation 12], is a function that maps points to channel gain, is the Fourier transform, is the x-axis position, is the y-axis position, silver th tone, is located ( , )at It means the reception value of the th tone.

[0214] The implementation of [Equation 12] exists in the discontinuous domain. However, the received signal at the location of the antenna elements on the surface of the base station array Only samples of can be obtained. For alignment in the form of the derived principle, the received signals can be rearranged into a three-dimensional data cube. Without loss of generality, the planar array is per row Horizontal antennas per column and per dog It may include vertical antennas of the dog. Any entry within the data cube can be expressed as follows [Mathematical Formula 13].

[0215]

[0216] In [Equation 13], Is th tone and horizontal axis th and vertical axes The entry corresponding to the th antenna, is the vertical axis index of the antenna, is the number of horizontal axis antennas, is the horizontal axis index of the antenna, Silver tone index, refers to the number of tones.

[0217] The data cube is used as input to the channel estimation algorithm. For convenience, a two-dimensional case is described below, but the following examples can also be extended to three-dimensional cases.

[0218] Estimation in two-dimensional space is as follows. A single frequency can be used for channel estimation. Accordingly, can be set to 1, and the notation silver As, expression silver can be simplified as follows. The single-frequency setting is a three-dimensional inverse of [Equation 12] using a preceding range-dependent filter. It provides a result in which the items are degraded into two-dimensional inverse FT items. In this case, the function that maps the coordinates of a point in space to a channel gain can be transformed as shown in [Mathematical Formula 14] below.

[0219]

[0220] In [Equation 15], Silver coordinates , , Channel gain corresponding to the point of , is the Fourier function, is located ( , ) received value, is the spatial wave number, is defined as, and is the wave number vector The horizontal axis component and the vertical axis component, refers to the depth axis or height axis coordinate from the antenna plane of the target.

[0221] Based on the relationship as in [Mathematical Formula 14], an algorithm for two-dimensional channel estimation in a discontinuous domain as in [Table 4] below can be performed.

[0222]

[0223] In [Table 4], and are the spatial wave numbers in the horizontal and vertical directions.

[0224] According to various embodiments of the present disclosure, semantic segmentation techniques can be used for antenna detection. Semantic segmentation features pixel-by-pixel classification and provides a neural network trained to segment the desired target from background pixels. An example of the structure of a detector including a neural network is shown in FIG. 21 below.

[0225] Fig. 21 illustrates an example of the structure of a neural network for determining an antenna position according to an embodiment of the present disclosure. Referring to Fig. 21, the detector It is designed to take as input an image (2101) of size and output an antenna detection result (2102), and each pixel value of the image has a corresponding size in the radiation pattern (e.g. ) is given by. The detector can utilize three dilated convolutional (DiConv) layers. Additionally, a ReLU layer can be embedded in each DiConv layer. In addition, a convolutional (Conv) layer and a softmax layer can be used to calculate the probability of each pixel being an antenna.

[0226] Figures 22a and 22b illustrate examples of radiation patterns and antenna position detection results according to one embodiment of the present disclosure. Figure 22a illustrates an example of a radiation pattern, and Figure 22b illustrates an example of an antenna position detection result corresponding to the radiation pattern of Figure 22a. In Figure 22a, bright areas indicate antennas of the terminal. In Figure 22b, pixels classified as background and pixels classified as antennas are expressed so as to be distinct from each other.

[0227] A neural network model, such as that shown in Figure 21, can be trained using training data. For example, the training data may be labeled data, including a mask that separates the antenna from the background in a radiation pattern image. The mask may indicate, on a pixel-by-pixel basis, whether each pixel in the image contains an antenna. Training can be performed by updating the weights of the layers included in the neural network model through backpropagation based on the results of inference or prediction performed using the data.

[0228] Estimation in 3D space is as follows. The difference between estimation in 3D space and 2D space is that a 3D inverse FT operation is required, rather than a 2D inverse FT operation. This difference requires replacing the filtering step with an interpolation step to extend the 2D case algorithm. The algorithm for channel estimation in 3D space can be summarized as shown in [Table 5] below.

[0229]

[0230] In [Table 5], and are the spatial wave numbers in the horizontal and vertical directions, is the spatial wave number in the depth direction for the discontinuous FT operation. In the algorithm as in [Table 5], the design of the detector is mostly similar to the detector of Fig. 21 for two dimensions, but differs in that the input and output are multi-channel images.

[0231] The SAOMP algorithm is as follows. The SAOMP algorithm according to various embodiments can be used for near-field channel estimation. The SAOMP algorithm described below can be applied not only to a planar array but also to an arbitrary linear sub-array of a planar array. Given angle information for a reference line on a planar array, a terminal can calculate the angle for an arbitrary line on the planar array using a priori of the array geometry.

[0232] three-element tuples , Explained using Considering the regions of the number of regions, a sounding-aided channel estimation technique, i.e., SAOMP technique, according to various embodiments of the present disclosure, which is a region-focusing variant of the omnidirectional OMP algorithm, can be performed. The transform matrix in SAOMP samples the polar domain from the angular dimension and the distance dimension. In the present disclosure, the region-focused transform matrix according to various embodiments is It is referred to as, means the number of samples in the angular domain. Angular sampling according to various embodiments -dimensional vector creates a vector. In particular, Is It contains segments of a dog, each segment being From It is an evenly spaced vector in the range up to . The length of the th segment is is a value proportional to, but rounded to an integer. In one embodiment, the angular sampling is concentrated in the area containing the terminal antennas estimated in the previous channel sounding step. Vector For any element within, the corresponding distance sample can be determined as shown in [Mathematical Formula 15] below.

[0233]

[0234] In [Equation 15], is a distance sample, Is and Integers that satisfy , are predefined hyper-parameters, means the i-th element of the angle vector. Here, refers to the minimum distance from the served sector to the base station.

[0235] Pairs of angle-distance samples is the domain-intensive transformation matrix Determines one column of the domain-intensive transformation matrix One column of can be determined as follows [Mathematical Formula 16].

[0236]

[0237] In [Equation 16], silver Index of The maximum value of, silver , is the antenna spacing of the base station, means distance sample.

[0238] Transformation matrix From the algorithm that generates the vector It is confirmed that must be broadcast to all terminals. Considering the characteristics of broadcast, vector Broadcasting of information about can be performed via a narrow-band feedback channel. Thereafter, the base station transmits pilot sequences to the terminals. Here, the pilot signals can be configured orthogonally to the terminals. For example, the pilot signals can be transmitted orthogonally via different time resources, different frequency resources, or different code resources. The pilot signal received by the terminals can be expressed as follows [Mathematical Formula 17].

[0239]

[0240] In [Equation 17], is the received pilot signal, is the pilot signal, is a channel, Silver noise, is the transformation matrix, stands for the polar-domain representation of the channel.

[0241] The terminal can parameterize the OMP algorithm using a transformation matrix and reconstruct the polar-domain representation of the channel from the received pilot signal. This procedure can be summarized as shown in [Table 6] below.

[0242]

[0243] The aforementioned SAOMP framework can be extended to near-field channel estimation based on neural network implementations of compressed sensing algorithms. Since OMP and various compressed sensing algorithms are iterative, neural network-based approaches, such as deep unfolding, can replace iterations using neural network layers. However, since learning-based techniques are also built on polar domain representations of channels, sounding-aided channel estimation techniques according to various embodiments can utilize neural network-based approaches. Based on different forms of transformation matrices, detected regions (e.g., regions detected in Step 4 of Tables 4 and 5) can be encoded in a form that fits the neural networks.

[0244] In the various embodiments described above, an ST signal may be used. The ST signal may be generated based on a predefined constellation, and the constellation may be designed based on at least one of the hardware of the transmitter and / or receiver and the channel environment. In other words, according to various embodiments of the present disclosure, a waveform for an analog phased array that enables simultaneous sensing and ST communication using the same unitary waveform may be designed. For example, the constellation may be designed to use the same unitary waveform for analog phased arrays. For example, to enable very fast analog modulation using limited-resolution phase shifters based on a block-circular correlation structure, the present disclosure proposes a constellation design technique that uses a binary Hadamard matrix for phase shifting in the analog domain and a diagonal rotation matrix for the digital domain. An optimization algorithm is proposed to maximize the minimum pairwise distance of a set of constellations. Furthermore, the present disclosure proposes a quantization technique for rotation matrices to enable a fully-analog transmitter architecture.

[0245] In the system according to the present disclosure, the transmitter It has a transmitting antenna and a receiver. The transmitter has a receiving antenna. The transmitter uses a unitary ST waveform according to an embodiment of the present disclosure. The ST waveform spans T time intervals (e.g., time slots). In the t-th time interval, where t=1,…,T, the transmitter transmits a symbol vector cast Modulated by the transmitting antennas. The ST waveform is It can be expressed as a matrix such as unitary constraint. is imposed on the waveform to optimize sensing performance. The unitary ST waveform enables simultaneous sensing and communication. Specifically, the waveform can be used to sense the position of one device and simultaneously transmit information to another device.

[0246] Fig. 23 illustrates an example of a constellation space of a signal according to one embodiment of the present disclosure. Fig. 23 illustrates proposed constellation points arranged on a Grassmann manifold (2310). Referring to Fig. 23, constellation points (e.g., , ) are arranged to maximize the minimum distance, which can be determined by solving the subspace filling problem of each constellation point. In this case, the subspace distance of two constellation points is can be expressed as

[0247] The communication link between the transmitter and receiver can be treated as a channel between the transmitting and receiving antennas. The channel between the transmitting and receiving antennas follows block fading, which does not change within the duration of the ST waveform spanning T time intervals. The signal received by the receiver can be expressed as follows [Mathematical Equation 18].

[0248]

[0249] In [Equation 18], is the receiving symbol, is a channel, is the transmission symbol, is the number of transmitting antennas, is the transmission SNR, is the number of time intervals, stands for Gaussian noise.

[0250] Since communication is performed in parallel with the sensing operation, there is no explicit channel estimation procedure, and thus both the transmitter and receiver have to calculate the channel matrix In the absence of channel state information (CSI), the present disclosure relies on Grassmann modulation, where information is embedded within the signal space of the ST waveform. The core idea of ​​Grassmann modulation is that left-multiplying using the channel matrix does not change the subspace embedded in the ST constellation. Detection is performed on noisy received symbols. This is done by selecting the constellation point with the smallest subspace distance compared to . For example, among the possible subspace indices, the chordal subspace distance as in [Mathematical Formula 19] below can be used.

[0251]

[0252] In [Equation 19], is the transmission symbol, is any other symbol, is the number of transmitting antennas, means the trace of the matrix.

[0253] The symbol detected at the receiver can be expressed as shown in [Mathematical Formula 20] below.

[0254]

[0255] In [Equation 20], is the detected symbol, is the Grassmann codebook, i.e., the set of constellation point candidates, means the received symbol.

[0256] One transmission symbol is transmitted over T time intervals. The baseband signal corresponding to one time interval is If you say so, Is The phase shifter passes through an array of phase shifters. The analog phase rotation is performed by the phase shifters, and the phase shift by the phase shifters is vector In other words, the modulated symbol vector corresponding to one time interval is can be expressed as . Here, since the phase shifters only change the phase of the signal without changing the magnitude, The elements of are constant modulus. Furthermore, due to the finite-resolution input of the phase shifter, the phase shift operation is quantized, Each element of belongs to a finite set. The ST constellation generated by analog phased arrays can be expressed as a matrix as shown in [Mathematical Formula 21] below.

[0257]

[0258] In [Equation 21], is the transmission symbol, is the phase shift vector corresponding to the time interval t, is the baseband signal corresponding to one time interval t, i.e., the phase rotation factor, is the phase transition matrix, is a vector on the main diagonal It means a square diagonal matrix containing elements of .

[0259] The ST constellation design according to various embodiments of the present disclosure aims to maximize the minimum distance between pairs of constellation points. This minimizes the error probability per pair in a noisy environment. The subspace filling problem that maximizes the minimum pairwise distance can be expressed as follows: [Mathematical Equation 22].

[0260]

[0261] In [Equation 22], is a collection of candidates for constellation points, is the i-th constellation point, is the jth constellation point, The number of points on the silver constellation, is the distance function, is the phase transition matrix The element located at the i-th row and j-th column, refers to the set of values ​​that each element of the phase transition matrix can have. Here, It could be.

[0262] Problems such as [Equation 22] fall under the category of subspace filling problems. The present disclosure proposes a solution to this problem through a systematic approach to designing constellation sets using satisfactory performance. To this end, modeling of a constellation set structured as in [Equation 23] can be utilized.

[0263]

[0264] In [Equation 23], is the kth constellation point, Silver is the first constellation point, stands for digital rotation matrix.

[0265] According to one embodiment, is the initial low-resolution unitary matrix, × From the Hadamard matrix of size can be determined by selecting the rows of the dog. Since the Hadamard matrix is ​​unitary, the selected rows are orthonormal, and accordingly can be guaranteed. The elements of the Hadamard matrix belong to the binary set {-1,1}, and the constellation designed accordingly can satisfy the limited-resolution constraint for 1-bit phase shifters.

[0266] According to one embodiment, a digital rotation matrix Is can be specified as . Here, are the integers to be optimized. These settings ensure that all constellations are unitary constraints (e.g. ) can be guaranteed to satisfy. Here, the diagonal elements of the rotation matrix include the function values ​​of a discrete-domain complex exponential function with period L, whose domain is given as a feasible region for the decision variables. And, the period L can be equal to the number of constellation points to be designed.

[0267] The proposed constellation has a circulant correlation structure, which can be expressed mathematically as [Mathematical Equation 24] below.

[0268]

[0269] In [Equation 24], is the i-th constellation point, is the jth constellation point, is the distance function, is the number of transmitting antennas, It means the first constellation point.

[0270] Accordingly, the optimization objective can be transformed as shown in [Mathematical Formula 25] below.

[0271]

[0272] In [Equation 25], is the i-th constellation point, is the jth constellation point, is the distance function, is the number of transmitting antennas, It means the first constellation point.

[0273] The optimization problem can be rephrased as [Mathematical Formula 26].

[0274]

[0275] In [Equation 26], are integers that are the target of optimization, Silver is the first constellation point, means the kth constellation point.

[0276] When the integral constraint for is relaxed, a continuous optimization problem can be obtained. Applying the relax-and-round approach, the optimization problem can be expressed as in [Mathematical Formula 27] below.

[0277]

[0278] In [Equation 27], are integers that are the target of optimization, is the i-th constellation point, means the jth constellation point.

[0279] The gradient descent algorithm can be effectively applied to solve the aforementioned problem. Due to the large search space of variables and the non-convex nature of the optimization problem, the initialization point can affect convergence performance. Therefore, in one embodiment, a random initialization scheme can be used. For example, the number of iterations Randomly through as many repetitions Inland can be initialized, and gradient descent can only be performed if the initialization point is sufficiently good (e.g., if the resultant minimum pairwise distance is better than a threshold).

[0280] The constellation design procedure according to one embodiment of the present disclosure is expressed as an algorithm as shown in [Table 7] below.

[0281]

[0282] The constellation designed as described above is - can be used by a transmitter including a bit phase shifter and an analog phase array. In this case, -The bit phase shifter shifts the phase of the input signal. That is, - The bit phase shifter assigns a phase factor to the unit signal converted into an RF signal. When a transmission symbol is expressed as the product of a phase shift vector and a phase rotation factor, - Phase rotation factor (e.g. [Equation 19]) by bit phase shifter (1740) ) can be applied to generate a unit signal. -The bit phase shifter (1740) may be referred to as an initial phase shifter.

[0283] An analog phased array may include multiple analog phase shifters. For example, an analog phased array may include N b- may include analog phase shifters of 1-bit or 1-bit. The phase shifters and antenna elements correspond 1:1, and each of the phase shifters can adjust the phase of a signal transmitted through the corresponding antenna element. In this case, the phase adjustment may be performed based on a constellation designed according to an embodiment. When a transmission symbol is expressed as a product of a phase shift vector and a phase-rotation factor, the phase shift vector (e.g., [Equation 19]) is expressed by an analog phase array. ) can be applied. Here, the phase-rotation factor can be understood as a baseband signal corresponding to one time interval t.

[0284] FIG. 24 illustrates an example of a procedure for performing near-field channel estimation according to one embodiment of the present disclosure. FIG. 24 also illustrates an operating method of a terminal.

[0285] Referring to FIG. 24, in step S2401, the terminal receives configuration information related to sounding. In other words, the terminal receives configuration information related to a signal transmitted on the uplink. For example, the configuration information may include at least one of a resource for transmitting a signal, a sequence constituting the signal, or values. Additionally, the terminal may transmit capability information related to sounding-assisted channel estimation to the base station, or perform further synchronization operations with other terminals.

[0286] In step S2403, the terminal transmits a sounding signal. In other words, the terminal transmits a reference signal for sounding. The signal transmitted in this step may be referred to as an uplink signal, an uplink reference signal, a sounding signal, a sounding reference signal, or other terms having equivalent technical meanings. The terminal may transmit a signal for sounding based on the configuration information received in step S2401. The uplink reference signal may occupy multiple tones. In one embodiment, the terminal may transmit the sounding signal through the same time-frequency resource as at least one other terminal. In one embodiment, the sounding signal may have a form that allows non-coherent detection.

[0287] In step S2405, the terminal receives configuration information related to channel estimation. For example, the configuration information may include information related to a downlink signal for channel estimation, information related to a resource for reporting the result of channel estimation, and information related to a channel estimation operation. According to one embodiment, the information related to the channel estimation operation may include information generated based on the sounding signal transmitted in step S2403. Specifically, the information generated based on the sounding signal may include information for determining the range of at least one basis vector included in a dictionary. The dictionary may be referred to as a sensing matrix, a transformation matrix, or another term having an equivalent technical meaning thereto. Here, the information elements included in the configuration information may be received via a single message or multiple messages.

[0288] In step S2407, the terminal receives a downlink reference signal. For example, the downlink reference signal may be received based on the configuration information received in step S2405. At the base station, the downlink reference signal may be transmitted together with downlink reference signals for at least one other terminal, and in this case, the downlink reference signals may be transmitted orthogonally to each other. Accordingly, the terminal can receive the downlink reference signal for itself without interference.

[0289] In step S2409, the terminal performs channel estimation. The terminal can estimate the channel using the received signal of the downlink reference signal. According to various embodiments, the terminal can estimate the channel by determining a support set by selecting at least one index among the columns of the dictionary based on an iterative algorithm. Additionally, although not illustrated in FIG. 24, the terminal can transmit information related to the estimated channel to the base station. That is, the terminal can transmit a report message including information related to the channel to the base station.

[0290] FIG. 25 illustrates an example of a procedure for assisting near-field channel estimation according to one embodiment of the present disclosure. FIG. 25 illustrates an operating method of a base station.

[0291] Referring to FIG. 25, in step S2501, the base station transmits configuration information related to sounding. In other words, the base station transmits configuration information related to a signal received on the uplink. For example, the configuration information may include at least one of a resource for transmitting a signal, a sequence constituting the signal, or values. Additionally, the base station may receive capability information related to sounding-assisted channel estimation from the terminal. According to one embodiment, the configuration information related to sounding may be provided for near-field channel estimation. Therefore, the base station may perform a radar operation using an ST waveform signal, and if the presence of at least one terminal in the near field is detected through the radar operation, the present step may be performed.

[0292] In step S2503, the base station receives a sounding signal. That is, the base station receives a reference signal for sounding. The signal received in this step may be referred to as an uplink signal, an uplink reference signal, a sounding signal, a sounding reference signal, or other terms having equivalent technical meanings. The base station may receive the sounding signal based on the configuration information transmitted in step S2503. The sounding signal may occupy multiple tones. In one embodiment, the base station may receive sounding signals from multiple terminals through the same time-frequency resource. In other words, the base station may receive overlapping sounding signals. In one embodiment, the sounding signals may have a form that allows non-coherent detection.

[0293] In step S2505, the base station transmits configuration information related to channel estimation. For example, the configuration information may include information related to downlink signals for channel estimation, information related to resources for reporting channel estimation results, and information related to channel estimation operations. According to one embodiment, the information related to channel estimation operations may include information generated based on the uplink reference signal received in step S2503. Specifically, the information generated based on the uplink reference signal may include information for determining a range for searching at least one basis in a dictionary. Here, the information elements included in the configuration information may be transmitted via a single message or multiple messages.

[0294] In step S2507, the base station transmits a downlink reference signal. For example, the downlink reference signal may be transmitted based on the configuration information transmitted in step S2505. At this time, downlink reference signals for multiple terminals may be transmitted together, and in this case, the downlink reference signals may be transmitted orthogonally to each other. Additionally, although not illustrated in FIG. 25, the base station may receive information related to the estimated channel from at least one terminal. That is, the base station may receive a report message including information related to the channel.

[0295] FIG. 26 illustrates an example of a procedure for estimating a channel based on an antenna position according to one embodiment of the present disclosure. FIG. 26 also illustrates an operating method of a terminal.

[0296] Referring to FIG. 26, in step S2601, the terminal receives configuration information based on the antenna position. Here, the configuration information is generated based on the antenna position of the terminal, and the antenna position may be determined based on an estimate from the base station. According to one embodiment, the configuration information based on the antenna position may include an SAOMP parameter. Specifically, the configuration information based on the antenna position may include at least one of angle information for the antenna of the terminal in the base station antenna array, a maximum angle value, a minimum angle value, and a size of a candidate area for the antenna position (e.g., the number of pixels in a radiation pattern image).

[0297] In step S2603, the terminal determines a dictionary search range based on the configuration information. In other words, the terminal can generate a region-focused dictionary based on the omnidirectional dictionary. According to various embodiments, the terminal can generate a region-focused dictionary based on configuration information based on antenna positions and distances between antennas of the base station. Specifically, the terminal can generate a region-focused dictionary based on at least one of an angle vector including angle values ​​falling within a range of maximum and minimum angle values, distance samples corresponding to each of the angle values, and distances between antennas of the base station.

[0298] In step S2605, the terminal determines channel information within the search range. In other words, the terminal determines the channel information by estimating the channel based on a region-intensive dictionary. According to various embodiments, the terminal can estimate the channel by identifying at least one column corresponding to a non-zero element of a sparse matrix among the columns of the region-intensive dictionary. Here, the sparse matrix is ​​a matrix representing the estimated channel. Specifically, the terminal can identify at least one column corresponding to a non-zero element based on repeated operations of sequentially removing elements corresponding to columns of a specific index of the region-intensive dictionary from a matrix including reception values ​​of pilot signals. For example, the terminal can estimate the channel based on an OMP technique.

[0299] Figure 27 illustrates an example of a procedure for providing auxiliary information based on antenna location according to one embodiment of the present disclosure. Figure 27 illustrates a method of operation of a base station. While Figure 27 illustrates operations for a single terminal, the procedure illustrated in Figure 27 can be performed for multiple terminals.

[0300] Referring to FIG. 27, in step S2701, the base station performs sensing using a signal. Here, the sensing is a radar operation, and the base station can estimate the direction and distance to at least one terminal. To this end, the base station can transmit a signal for radar operation (e.g., an ST signal) and receive a signal reflected by at least one terminal. Based on the reflected signal, the base station performs a radar operation, thereby obtaining distance and angle information for the terminal.

[0301] In step S2703, the base station generates information related to the radiation pattern of the sounding signal. Here, the information related to the radiation pattern may take the form of an image, and the signal includes a signal transmitted from the terminal for sounding. The image represents the antenna position of the terminal as observed from a reference point of the array of the base station. According to various embodiments, the base station may generate an image representing the radiation pattern by performing an FFT operation, filtering, and an IFFT operation on the received values ​​of the signal.

[0302] In step S2705, the base station estimates the antenna position based on the radiation pattern and the sensing result. The base station can estimate the antenna position based on an image representing the radiation pattern. To this end, according to one embodiment, the base station can use a neural network model. For example, the neural network model can have a structure as shown in FIG. 15. Through this, the base station can obtain at least one of information related to the position of the antenna, such as information on the angle formed by the terminal's antenna with respect to a reference point and a reference line on the base station's antenna array, and information on the observed size. In addition, based on the distance and angle obtained by the sensing performed in step S2701, the base station can obtain the coordinates of the terminal on an axis perpendicular to the base station's antenna plane, i.e., the height coordinates. Through this, the base station can estimate the three-dimensional position of the terminal's antenna.

[0303] In step S2707, the base station generates auxiliary information including information related to the antenna position. The information related to the antenna position may include at least one of angle information for the terminal's antenna, a maximum angle value, a minimum angle value, and the size of a candidate area for the antenna position (e.g., the number of pixels in a radiation pattern image). Subsequently, although not illustrated in FIG. 27, the base station may transmit the generated auxiliary information to the terminal. For example, the auxiliary information may be transmitted as configuration information for channel estimation.

[0304] 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).

[0305] 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.

[0306] 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.

[0307] 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.

[0308] Additionally, embodiments of the present disclosure can be applied to various applications such as autonomous vehicles and drones.

Claims

1. In a method of operating a first device in a wireless communication system, A step of transmitting a first signal of a non-coherent detectable structure; A step of transmitting first setting information related to sounding to a second device; A step of receiving a second signal based on the first setting information; A step of transmitting second setting information related to channel estimation to the second device; A step of transmitting a third signal to the second device based on the second setting information, A method wherein the second setting information is based on an antenna position of the second device estimated based on the first signal and the second signal, and includes a range of at least one basis vector included in a dictionary.

2. In claim 1, The step of transmitting first setting information related to sounding to the second device is: A method comprising the step of transmitting the first setting information when the second device is detected by the first signal.

3. In claim 1, A method wherein the first signal comprises a communication signal for transmitting information to a third device and is used for radar operation with respect to the second device.

4. In claim 1, The above first signal is generated based on a predefined constellation, The above constellation is a method for determining a constellation design expressed as a product of an initial matrix and a rotation matrix by optimizing decision variables that determine diagonal elements of the rotation matrix based on the minimum pairwise distance between constellation points.

5. In claim 4, The diagonal elements of the rotation matrix include the function values ​​of a discrete-domain complex exponential function with period L, whose domain is given as a feasible region for the decision variables, The above period L is set to be equal to the number of constellation points.

6. In claim 1, A method wherein the second configuration information comprises angle information for an antenna of the second device in the antenna array of the first device, and includes at least one of a maximum angle value, a minimum angle value, and a size of a candidate area for an antenna position.

7. In claim 1, A method further comprising the step of estimating the antenna position of the second device based on the second signal.

8. In claim 7, The step of estimating the antenna position of the second device is: a step of generating an image representing a radiation pattern for the second signal; and A method comprising the step of estimating the antenna position of the second device based on the image.

9. In claim 8, The steps for generating the above image are: A step of performing a Fourier transform on the reception values ​​of the second signal at points included in the space represented by the image; A step of performing filtering on the result of the above Fourier transform; and A method comprising the step of performing an inverse-Fourier transform on the result of the above filtering.

10. In claim 1, A step of receiving a second signal including feedback information related to a channel generated using the first signal from a fourth device; and Further comprising a step of determining channel information based on the above feedback information, The above feedback information includes information related to the distance between each part of the first signal and the channel information, 11. In claim 10, The step of determining the above channel information is: A step of determining weights based on the above feedback information; A step of determining a combined combination matrix of the above parts using the above weights; A method comprising the step of determining the channel information based on the above combination matrix.

12. In claim 11, The above weights are determined by normalizing the values ​​included in the feedback information to the size of the transmission signal matrix of the corresponding portion.

13. In claim 11, The above combination is determined by a weighted sum using the weights for the product of the transmission signal matrix of each of the above parts and the conjugate transpose of the transmission signal matrix.

14. In claim 11, A method wherein the channel information includes at least a portion of the eigenspace of the coupling matrix.

15. In a first device in a wireless communication system, Transmitter and receiver; and comprising a processor connected to the above transceiver, The above processor, Transmitting a first signal of a non-coherent detectable structure, Transmit first setting information related to sounding to the second device, Receive a second signal based on the above first setting information, Transmit second setting information related to channel estimation to the second device, Controlling to transmit a third signal to the second device based on the second setting information; The second setting information is based on an antenna position of the second device estimated based on the first signal and the second signal, and includes a range of at least one basis vector included in a dictionary.

16. In communication devices, At least one processor; At least one computer memory coupled 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 transmitting a first signal of a non-coherent detectable structure; A step of transmitting first setting information related to sounding to a second device; A step of receiving a second signal based on the first setting information; A step of transmitting second setting information related to channel estimation to the second device; A step of transmitting a third signal to the second device based on the second setting information, A communication device wherein the second setting information is based on an antenna position of the second device estimated based on the first signal and the second signal, and includes a range of at least one basis vector included in a dictionary.

17. 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 first device to: Transmitting a first signal of a non-coherent detectable structure, Transmit first setting information related to sounding to the second device, Receive a second signal based on the above first setting information, Transmit second setting information related to channel estimation to the second device, Controlling to transmit a third signal to the second device based on the second setting information; A non-transitory computer-readable medium wherein the second setting information is based on an antenna position of the second device estimated based on the first signal and the second signal, and includes a range of at least one basis vector included in a dictionary.

Images