Device and method for generating multi-functional signal in wireless communication system

Abstract

The purpose of the present disclosure is to generate a multi-functional signal in a wireless communication system. This method for operating a device may comprise the steps of: generating information bits; generating at least one codeword by encoding the information bits; generating at least one symbol corresponding to at least a part of the at least one codeword; and transmitting the at least one symbol.

Description

Device and method for generating multi-functional signals in wireless communication systems

[0001] The following description relates to a wireless communication system, and to a device and method for generating 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 solutions.

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

[0005] The present disclosure may provide a device and method for generating a signal of a space-time (ST) waveform in a wireless communication system.

[0006] The present disclosure may provide a device and method for designing a constellation for an ST waveform in a wireless communication system.

[0007] 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.

[0008] 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.

[0009] The present disclosure can provide a device and method for designing a constellation diagram by considering a quantized phase shifter with a limited number of bits in a wireless communication system.

[0010] The present disclosure can provide a device and method for generating a signal of an ST waveform using a quantized phase shifter with a limited number of bits in a wireless communication system.

[0011] The present disclosure may provide a device and method for designing a constellation including symbols distinguished by the number of powers of a given phase rotation matrix in a wireless communication system.

[0012] The present disclosure can provide a device and method for optimizing decision variables that determine diagonal elements of a phase rotation matrix constituting a symbol in a wireless communication system.

[0013] The present disclosure can provide a device and method for solving an optimization problem of maximizing the minimum pairwise distance of constellation points in a wireless communication system.

[0014] The present disclosure may provide an apparatus and method for applying a relax-and-round approach to an optimization problem of maximizing the minimum pairwise distance of constellation points in a wireless communication system.

[0015] The present disclosure can provide a device and method for solving an optimization problem of maximizing the minimum pairwise distance of constellation points in a wireless communication system using a gradient descent technique.

[0016] 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.

[0017] As an example of the present disclosure, a method of operating a device for transmitting a signal in a wireless communication system may include the steps of generating information bits, generating at least one codeword by encoding the information bits, generating at least one symbol corresponding to at least a portion of the at least one codeword, and transmitting the at least one symbol. A constellation for generating the at least one symbol may be determined by optimizing decision variables that determine diagonal elements of a rotation matrix for a constellation design expressed as a product of an initial matrix and a rotation matrix based on a minimum pairwise distance between constellation points.

[0018] As an example of the present disclosure, a device for transmitting a signal in a wireless communication system includes a transceiver and a processor connected to the transceiver, wherein the processor generates information bits, generates at least one codeword by encoding the information bits, generates at least one symbol corresponding to at least a part of the at least one codeword, and controls transmission of the at least one symbol, wherein a constellation for generating the at least one symbol is determined by optimizing decision variables that determine diagonal elements of a rotation matrix for a constellation design expressed as a product of an initial matrix and a rotation matrix based on a minimum phase-wise distance between constellation points.

[0019] As an example of the present disclosure, a communication device includes at least one processor, and at least one computer memory coupled to the at least one processor and storing instructions that, when executed by the at least one processor, direct operations, wherein the operations may include: generating information bits; generating at least one codeword by encoding the information bits; generating at least one symbol corresponding to at least a portion of the at least one codeword; and transmitting the at least one symbol. A constellation for generating the at least one symbol may be determined by optimizing decision variables that determine diagonal elements of a rotation matrix for a constellation design expressed as a product of an initial matrix and a rotation matrix based on a minimum phase-wise distance between constellation points.

[0020] 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 device to generate information bits, generate at least one codeword by encoding the information bits, generate at least one symbol corresponding to at least a portion of the at least one codeword, and transmit the at least one symbol, wherein a constellation for generating the at least one symbol can be determined by optimizing decision variables that determine diagonal elements of a rotation matrix for a constellation design expressed as a product of an initial matrix and a rotation matrix based on a minimum phase-wise distance of constellation points.

[0021] The above-described aspects of the present disclosure are only some of the preferred embodiments of the present disclosure, and various embodiments reflecting the technical features of the present disclosure can be derived and understood by a person having ordinary skill in the art based on the detailed description of the present disclosure to be described below.

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

[0023] According to the present disclosure, multi-functional signals can be effectively generated.

[0024] The effects that can be obtained from the embodiments of the present disclosure are not limited to the effects mentioned above, and other effects not mentioned can be clearly derived and understood by those skilled in the art to which the technical configuration of the present disclosure is applied, from the description of the embodiments of the present disclosure below. In other words, unintended effects resulting from implementing the configuration described in the present disclosure can also be derived from the embodiments of the present disclosure by those skilled in the art.

[0025] The accompanying drawings are intended to aid understanding of the present disclosure and, together with detailed descriptions, may provide embodiments of the present disclosure. However, the technical features of the present disclosure are not limited to specific drawings, and the features disclosed in each drawing may be combined with each other to form new embodiments. Reference numerals in each drawing may indicate structural elements.

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

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

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

[0029] Figure 4 illustrates a communication procedure between a terminal and a base station applicable to the present disclosure.

[0030] FIG. 5 illustrates an example of a communication structure that can be provided in a 6G (6th generation) system applicable to the present disclosure.

[0031] Figure 6 illustrates an electromagnetic spectrum applicable to the present disclosure.

[0032] Figure 7 illustrates a THz communication method applicable to the present disclosure.

[0033] FIG. 8 illustrates a THz wireless communication transceiver applicable to the present disclosure.

[0034] FIG. 9 illustrates a THz signal generation method applicable to the present disclosure.

[0035] FIG. 10 illustrates a wireless communication transceiver applicable to the present disclosure.

[0036] Figure 11 illustrates a transmitter structure applicable to the present disclosure.

[0037] Figure 12 illustrates a modulator structure applicable to the present disclosure.

[0038] FIG. 13 illustrates an example of a communication scenario using multi-functional signals according to one embodiment of the present disclosure.

[0039] FIG. 14 illustrates an example of a constellation space of a signal according to one embodiment of the present disclosure.

[0040] FIG. 15 illustrates an example of a transmitter structure according to one embodiment of the present disclosure.

[0041] FIG. 16 illustrates another example of a transmitter structure according to one embodiment of the present disclosure.

[0042] FIG. 17 illustrates another example of a transmitter structure according to one embodiment of the present disclosure.

[0043] FIG. 18 illustrates an example of a procedure for transmitting a signal according to one embodiment of the present disclosure.

[0044] FIG. 19 illustrates an example of a procedure for receiving a signal according to one embodiment of the present disclosure.

[0045] FIG. 20 illustrates an example of a procedure for designing a constellation diagram according to one embodiment of the present disclosure.

[0046] Figures 21a to 21c illustrate the performance of a channel feedback technique according to embodiments of the present disclosure.

[0047] The following embodiments combine the components and features of the present disclosure in a predetermined form. Each component or feature may be considered optional unless explicitly stated otherwise. Each component or feature may be implemented without being combined with other components or features. Furthermore, some components and / or features may be combined to form embodiments of the present disclosure. The order of operations described in the embodiments of the present disclosure may be changed. Some components or features of one embodiment may be included in another embodiment or may be replaced with corresponding components or features of another embodiment.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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).

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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).

[0060] 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.

[0061] 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.

[0062] Communication system applicable to the present disclosure

[0063] 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.

[0064] 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.

[0065] Figure 1 illustrates an example of a communication system applied to the present disclosure.

[0066] 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.

[0067] 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).

[0068] 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.

[0069] Devices applicable to the present disclosure

[0070] FIG. 2 illustrates an example of a wireless device applicable to the present disclosure.

[0071] 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).

[0072] 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.

[0073] 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.

[0074] At least one processor (202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. The at least one processor (202) may be implemented by hardware, firmware, software, or a combination thereof. For example, at least one application specific integrated circuit (ASIC), at least one digital signal processor (DSP), at least one digital signal processing device (DSPD), at least one programmable logic device (PLD), or at least one field programmable gate array (FPGA) may be included in the at least one processor (202). The descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. The descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document may be included in the at least one processor (202), or may be stored in at least one memory (204) and driven by the at least one processor (202). The descriptions, functions, procedures, suggestions, methods and / or flowcharts disclosed in this document may be implemented using firmware or software in the form of code, instructions and / or sets of instructions.

[0075] 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.

[0076] 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.

[0077] 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).

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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).

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 6G communication systems and core implementation technologies of 6G systems

[0097] 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.

[0098] 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.

[0099] Per device peak data rate1 TbpsE2E latency1 msMaximum spectral efficiency100 bps / HzMobility supportup to 1000 km / hrSatellite integrationFullyAIFullyAutonomous vehicleFullyXRFullyHaptic CommunicationFully

[0100] 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.

[0101] 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, a 6G system is expected to have 50 times higher simultaneous wireless communication connectivity than a 5G wireless communication system. URLLC, a key feature of 5G, is expected to become an even more important technology in 6G communications by providing end-to-end latency of less than 1 ms. Furthermore, 6G systems will have significantly superior volumetric spectral efficiency, unlike the frequently used area spectral efficiency. 6G systems can provide extremely long battery life and advanced battery technologies for energy harvesting, so mobile devices in 6G systems may not need to be separately charged.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] 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

[0108] 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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).

[0114] Specific embodiments of the present disclosure

[0115] The present disclosure relates to a technique for generating signals in a wireless communication system. In particular, the present disclosure relates to a technique for generating multi-functional signals. Specifically, the present disclosure proposes various embodiments for designing a constellation to effectively utilize multi-functional signals, and for generating and interpreting the multi-functional signals using the designed constellation.

[0116] Next-generation communication systems, such as 6G (6th generation), are being considered to have sensing capabilities as a native capability. The integration of sensing capabilities into 6G enables a wide range of use cases, from object localization and tracking to high-resolution environmental imaging and activity recognition. The coexistence of communications and sensing has given rise to a growing research trend called integrated sensing and communications (ISAC). Instead of viewing sensing and communications as independent functions competing for resources (e.g., energy and spectral bands), ISAC implements sensing and communications on a shared infrastructure that reuses resources for both. This is underpinned by commonality between sensing and communications hardware, utilizing phased arrays for radar and massive MIMO (multiple input multiple output) communications.

[0117] One of the key research issues for ISAC is the design of a unified waveform for simultaneous sensing and communication. Existing designs embed information in chirp signals and construct sensing functions from orthogonal frequency division multiplexing (OFDM) waveforms. However, research on multifunctional space-time (ST) waveforms, known to minimize the Cramer-Rao error bound, is lacking. Effective sensing requires that the signals transmitted by all antennas be mutually orthogonal, a characteristic known as a unitary ST waveform. Therefore, non-coherent ST communication using a unitary waveform has emerged as a natural choice for transmitting additional information by reusing the same waveform used for sensing. Due to its advantage of not requiring explicit channel estimation, non-coherent ST communications have witnessed a recent revival, extending into many directions, including applications in automatic constellation recognition, massive MIMO, and full-duplex relaying. Therefore, the present disclosure proposes a technique that enables ISAC operation using ST waveforms for non-coherent ST communications.

[0118] The basic idea of ​​non-coherent ST modulation is to embed information in the ST signal space, which is invariant to a random MIMO channel. The information can be detected at the receiver without explicit channel estimation. Previous research has shown that unitary ST waveforms can achieve channel capacity in high signal-to-noise ratio (SNR) environments. The performance of non-coherent communication is highly dependent on the constellation used. The minimum pairwise distance is a commonly used metric for constellations. Considering this metric, constellation design is known as the Grassmannian packing problem, which involves packing subspaces within the Grassmannian manifold so as to maximize their mutual distances.

[0119] To this end, systematic approaches to constellation design using block-circulant structures, gradient descent-based approaches with relaxation and parameterization in tangent space, etc. have been proposed. Recently, Grassmann codebooks have been designed using sequential smooth optimization on manifolds. The aforementioned algorithms assume that the designed constellation is implemented using pull-precision, which requires that the number of transmit antennas is equal to the number of radio frequency (RF) chains. However, since sensing and communication in 6G use millimeter-wave or THz frequency bands and very large antenna arrays, a full-digital implementation requires complex and dedicated hardware.

[0120] Alternatively, analog phased arrays, consisting of analog phase shifters with low processing delay and cost and finite resolution inputs, can be used in the transmitter. Hybrid designs using these analog phased arrays offer low hardware complexity, low delay, and low energy consumption. However, direct quantization of constellations designed for hybrid precoders can degrade performance. This problem requires tailoring ST constellation designs to analog phased arrays, which imposes extra constraints on the supported signal structures and limits the constellation's degrees of freedom.

[0121] Accordingly, the present disclosure proposes a waveform design technique for sensing and ST communication using the same unitary waveform for analog phased arrays. In other words, the present disclosure proposes a waveform design technique for analog phased arrays that enables simultaneous sensing and ST communication using the same unitary waveform. 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 constellation set. Furthermore, the present disclosure proposes a quantization technique for the rotation matrix to enable a fully analog transmitter architecture.

[0122] The system models applicable to the present disclosure are as follows.

[0123] The transmitter is 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. A specific example of this multi-functionality is shown in Figure 13 below.

[0124] FIG. 13 illustrates an example of a communication scenario using a multi-functional signal according to one embodiment of the present disclosure. Referring to FIG. 13, a device (1320) performing a transmission operation (e.g., a base station) transmits a signal generated according to various embodiments of the present disclosure to a plurality of other devices (1310-1 to 1310-3) (e.g., terminals). Here, the signal has a structure capable of non-coherent detection and may be based on, for example, an ST waveform. In this case, the signal may be used to convey information to a first device (1310-1), to provide channel feedback to a second device (1310-2), and to perform a sensing operation to a third device (1310-3). That is, a signal generated based on a constellation designed according to various embodiments may support various functions such as communication, channel feedback, and sensing.

[0125] Fig. 14 illustrates an example of a constellation space of a signal according to an embodiment of the present disclosure. Fig. 14 illustrates proposed constellation points arranged on a Grassmann manifold (1410). Referring to Fig. 14, 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

[0126] 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 1].

[0127]

[0128] In [Equation 1], 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.

[0129] 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 compute 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 2] below can be used.

[0130]

[0131] In [Equation 2], is the transmission symbol, is any other symbol, is the number of transmitting antennas, means the trace of the matrix.

[0132] The symbol detected by the receiver can be expressed as shown in [Mathematical Formula 3] below.

[0133]

[0134] In [Equation 3], is the detected symbol, is the Grassmann codebook, i.e., the set of constellation point candidates, means the received symbol.

[0135] 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 3] below.

[0136]

[0137] In [Equation 4], 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 .

[0138] 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 5].

[0139]

[0140] In [Equation 5], 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.

[0141] Problems such as [Equation 5] 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, a constellation set design structured as shown in [Equation 6] below can be utilized.

[0142]

[0143] In [Equation 6], is the kth constellation point, Silver is the first constellation point, stands for digital rotation matrix.

[0144] 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.

[0145] 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.

[0146] The proposed constellation has a circulant correlation structure, which can be expressed mathematically as shown in [Mathematical Equation 7] below.

[0147]

[0148] In [Equation 7], 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.

[0149] Accordingly, the optimization objective can be converted as shown in [Mathematical Formula 8] below.

[0150]

[0151] In [Equation 8], 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.

[0152] The optimization problem can be rephrased as [Mathematical Formula 9].

[0153]

[0154] In [Equation 9], are integers that are the target of optimization, Silver is the first constellation point, means the kth constellation point.

[0155] When the integral constraint for is relaxed, a continuous optimization problem can be obtained. By applying the relax-and-round approach, the optimization problem can be expressed as in [Mathematical Formula 10] below.

[0156]

[0157] In [Equation 10], are integers that are the target of optimization, is the i-th constellation point, means the jth constellation point.

[0158] 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 Gradient descent can be performed only if the initialization point is sufficiently good (e.g., the resultant minimum pairwise distance is better than a threshold).

[0159] The constellation design procedure according to one embodiment of the present disclosure is expressed as an algorithm as shown in [Table 3] below.

[0160]

[0161] FIG. 15 illustrates an example of a transmitter structure according to one embodiment of the present disclosure. FIG. 15 illustrates the structure of a transmitter, which may be understood as a portion of the structure of any one of various devices, such as a base station, a terminal, or a relay station. In other words, the structure illustrated in FIG. 15 may be understood as a portion of the structure of the device illustrated in FIG. 2 or FIG. 3, or as an expression of another perspective.

[0162] Referring to FIG. 15, the transmitter includes a baseband block (1510), an RF chain (1530), a phased array (1550), and a transmit antenna array (1570).

[0163] The baseband block (1510) generates a baseband signal. For example, the baseband block (1510) may include a modem, a digital to analog converter (DAC), etc. Accordingly, the baseband block (1510) may output a baseband analog signal. The RF chain (1530) converts the baseband signal into an RF band signal. Furthermore, the RF chain (1530) may amplify the signal. The RF chain (1530) may include an oscillator, a mixer, an amplifier, etc. The phased array (1550) includes a plurality of analog phase shifters, and the transmit antenna array (1570) includes a plurality of antenna elements. The phase shifters and the antenna elements correspond one to one, and each of the phase shifters may adjust the phase of a signal transmitted through a corresponding antenna element.

[0164] Fig. 16 illustrates another example of a transmitter structure according to one embodiment of the present disclosure. Fig. 16 illustrates the structure of a transmitter, which may be understood as a portion of the structure of any one of various devices, such as a base station, a terminal, or a relay station. In other words, the structure illustrated in Fig. 16 may be understood as a portion of the structure of the device illustrated in Fig. 2 or Fig. 3, or as an expression of another perspective.

[0165] Referring to FIG. 16, the transmitter includes a baseband block (1610), DACs (1620), an RF chain (1630), a phased array (1650), and a transmit antenna array (1670).

[0166] The baseband block (1610) generates a baseband signal. For example, the baseband block (1610) may include a modem. The baseband block (1610) may output a baseband digital signal. The DACs (1620) may include a first DAC that converts a digital signal of an I channel (e.g., Re(·)) to an analog signal and a second DAC that converts a digital signal of a Q channel (e.g., Im(·)) to an analog signal. The RF chain (1630) converts the baseband signal to a signal in the RF band. Furthermore, the RF chain (1630) may amplify the signal. The RF chain (1630) may include an oscillator, a phase shifter, a mixer, an IQ summer, an amplifier, and the like. The phased array (1650) includes a plurality of analog phase shifters, and the transmit antenna array (1670) includes a plurality of antenna elements. The phase shifters and antenna elements correspond 1:1, and each phase shifter can adjust the phase of a signal transmitted through the corresponding antenna element.

[0167] According to the structure as in Fig. 16, in each time interval, the modulation symbol vector is a full precision phase rotation factor , and the full precision phase rotation factor can be implemented in the digital domain. From a hardware perspective, the factor A digital baseband component may be required that outputs two data streams corresponding to the I channel and the Q channel of the antenna. The two data streams may be converted to analog signals by a DAC. Accordingly, the two streams of analog signals sequentially pass through an RF chain and an analog phased array. Full precision of the phase rotation may require intricate digital baseband processing as well as full-resolution DACs. This requirement may be a factor that makes practical implementation difficult. Therefore, a transmitter structure according to a fully analog implementation such as that shown in FIG. 17 below may be used.

[0168] Fig. 17 illustrates another example of a transmitter structure according to one embodiment of the present disclosure. Fig. 17 illustrates the structure of a transmitter, which may be understood as a portion of the structure of any one of various devices, such as a base station, a terminal, or a relay station. In other words, the structure illustrated in Fig. 17 may be understood as a portion of the structure of the device illustrated in Fig. 2 or Fig. 3, or as a representation of another perspective.

[0169] Referring to Figure 17, the transmitter comprises a unit signal generator (1710), an RF chain (1730), - Includes a bit phase shifter (1740), a phase array (1750), and a transmitting antenna array (1770).

[0170] The unit signal generator (1710) generates a unit signal that serves as the basis of a transmission symbol based on a constellation designed according to various embodiments. The unit signal generator (1710) can output an I channel signal and a Q channel signal as a baseband analog signal of the unit signal. The RF chain (1730) converts the baseband signal into a signal in the RF band. Furthermore, the RF chain (1730) can amplify the signal. The RF chain (1730) can include an oscillator, a phase shifter, a mixer, an IQ adder, an amplifier, and the like.

[0171] - The bit phase shifter (1740) shifts the phase of the input signal. That is, - The bit phase shifter (1740) provides a phase factor to the unit signal converted into an RF signal. When a transmission symbol is expressed as a product of a phase shift vector and a phase rotation factor, - Phase rotation factor (e.g. [Equation 4]) 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.

[0172] The phased array (1750) includes a plurality of analog phase shifters, and the transmit antenna array (1770) includes a plurality of antenna elements. For example, the phased array (1750) 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 4]) is expressed by the phase array (1750). ) can be applied. Here, the phase-rotation factor can be understood as a baseband signal corresponding to one time interval t.

[0173] According to the various embodiments described above, a constellation for generating a non-coherent detectable signal can be designed. For example, the non-coherent detectable signal can be based on an ST waveform. The signal generated based on the constellation designed according to the various embodiments can be utilized for various purposes (e.g., data transmission, radar sensing, channel estimation, synchronization, etc.). Accordingly, the signal generated based on the proposed constellation can be generated and transmitted by various devices. According to the various embodiments, the signal generated based on the proposed constellation can be generated and transmitted not only by uplink communication of a UE and downlink communication of a base station, but also by a relay station, a vehicle, a roadside unit (RSU), etc.

[0174] FIG. 18 illustrates an example of a procedure for transmitting a signal according to one embodiment of the present disclosure. FIG. 18 illustrates an operation method of a device (e.g., UE, base station, relay station, vehicle, RSU, etc.) for transmitting a signal.

[0175] Referring to FIG. 18, in step S1801, the device generates information bits. The signal generated based on the constellation according to the proposed technology has the function of transmitting data, and thus, information bits representing the data transmitted through the signal can be generated. Although not illustrated in FIG. 18, the device can perform at least one processing of channel coding, scrambling, and rate matching on the information bits. Specifically, the device can generate information bits, generate at least one codeword by encoding the information bits, and perform scrambling and rate matching on bits within the at least one codeword. However, when transmitting a signal for a function other than data transmission, the information bits can be generated based on other criteria, and processing such as channel coding can be omitted.

[0176] In step S1803, the device determines a transmission sequence corresponding to the information bits. That is, the device determines a transmission sequence corresponding to the information bits based on a specified constellation. The transmission sequence is a set of values ​​representing a single constellation point based on the constellation according to the proposed technology, and includes values ​​occupying a specified number of time resources and space resources. In other words, the device identifies a single constellation point corresponding to the information bit in the constellation.

[0177] In step S1805, the device generates a signal based on the transmission sequence. The device generates a physical signal representing the transmission sequence. To this end, the device may perform various signal processing in the physical layer. For example, processing such as RF conversion, amplification, and phase shifting may be performed. According to one embodiment, when the device uses an analog phased array, the device may identify a phase rotation factor and a phase shift vector corresponding to the transmission sequence, i.e., for a transmission symbol, apply an initial phase value to a unit signal using the phase rotation factor, and apply phase values ​​for each antenna element using the phase shift vector.

[0178] In step S1807, the device transmits a signal. The signal generated in step S1805 is radiated via at least one antenna for a plurality of time intervals. For example, the signal is transmitted via a plurality of antenna elements connected to an analog phased array.

[0179] FIG. 19 illustrates an example of a procedure for receiving a signal according to one embodiment of the present disclosure. FIG. 19 illustrates an operation method of a device (e.g., UE, base station, relay station, vehicle, RSU, etc.) that transmits a signal.

[0180] In step S1901, the device receives a signal. The device receives the signal for a plurality of time intervals via at least one receiving antenna. The device determines a boundary of a duration corresponding to one constellation point in the received signal, and can obtain a signal corresponding to at least one constellation point based on the determined boundary.

[0181] In step S1903, the device detects a signal based on the constellation. The device may detect the signal based on a non-coherent method. For example, the device may perform a correlation operation on the received signal using signal candidates based on the constellation, and estimate the transmitted signal based on the correlation operation.

[0182] In step S1905, the device performs an operation using the detected signal. For example, the device may acquire data by interpreting the detected signal, estimate a channel using the detected signal, or obtain synchronization using the detected signal. Additionally, the device may perform a feedback operation (e.g., channel information feedback) corresponding to the operation performed using the detected signal.

[0183] Fig. 20 illustrates an example of a procedure for designing a constellation according to one embodiment of the present disclosure. In Fig. 20, the entity designing the constellation is referred to as a "device." However, since the device designing the constellation and the device transmitting / receiving signals using the designed constellation may not be the same, the procedure of Fig. 20 may be performed by a device different from the device performing the procedure of Fig. 18 or Fig. 19.

[0184] In step S2001, the device represents constellation points as a product of an initial matrix and a rotation matrix. Here, the initial matrix is ​​one of the constellation points and has the form of a low-resolution unitary matrix. In one embodiment, the unitary matrix can be determined by selecting as many rows as the number of transmit antennas from a Hadamard matrix. The rotation matrix is ​​a diagonal matrix that represents various constellation points by exponentiation. That is, the constellation points are represented as a product of exponentiations of the unitary matrix and the rotation matrix.

[0185] In step S2003, the device performs optimization on decision variables of the diagonal elements of the rotation matrix. The rotation matrix included in the constellation points expressed in S2001 is a diagonal matrix and includes diagonal elements. By optimizing the decision variables that determine the diagonal elements, the minimum distance between constellation points can be maximized. The optimization of the decision variables can be performed through iteration operations, through which a set of constellation points can be determined.

[0186] As described above, a constellation can be designed. A signal generated based on the constellation occupies a predetermined number of time and space resources. Therefore, for use in various communication environments, various constellations can be defined, each corresponding to a different combination of the number of time and space resources allocable to a single symbol. In this case, a device performing communication using a constellation according to the proposed technology can select an appropriate constellation from among multiple available constellations, depending on the given communication environment, and generate and transmit a signal based on the selected constellation.

[0187] Figures 21a to 21c illustrate the performance of a channel feedback technique according to embodiments of the present disclosure.

[0188] Figures 21a and 21b show the block error rate (BER) performance of the proposed technique. Referring to Figures 21a and 21b, the design based on the proposed technique demonstrates performance that is comparable to or slightly superior to that of the baseline algorithm, sequential smooth optimization (SSO), and DFT-based techniques.

[0189] Figure 21c shows the performance evaluation results of quantized phase rotation. Referring to Figure 21c, the BER is compared when the number of bits for the initial phase rotation is quantized to 1, 2, or 3. It is confirmed that 2-bit and 3-bit quantization incur negligible performance loss compared to the non-quantized case. However, it is confirmed that a relatively large performance loss occurs when the resolution of the initial phase rotation is 1-bit.

[0190] 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).

[0191] 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.

[0192] 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.

[0193] 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.

[0194] 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 device for transmitting a signal in a wireless communication system, Step of generating information bits; A step of generating at least one codeword by encoding information bits; generating at least one symbol corresponding to at least a part of said at least one codeword; and comprising a step of transmitting at least one symbol, A method for generating at least one symbol by determining a constellation by optimizing decision variables that determine diagonal elements of a rotation matrix for a constellation design expressed as a product of an initial matrix and a rotation matrix based on the minimum pairwise distance between constellation points.

2. In claim 1, The above initial matrix is ​​one of the points included in the constellation diagram.

3. In claim 1, The above initial matrix has the form of a low-resolution unitary matrix, The above initial matrix is ​​determined by selecting from a Hadamard matrix as many rows as the number of spatial resources occupied by symbols based on the constellation diagram.

4. In claim 1, The above constellation includes a plurality of constellation points corresponding to a plurality of symbol candidates, A method in which the plurality of constellation points are expressed as a product of the powers of the initial matrix and the rotation matrix, and are distinguished from each other by the number of powers of the rotation matrix.

5. In claim 1, The above decision variables are optimized to maximize the minimum pairwise distance between the constellation points.

6. In claim 1, A method wherein at least one symbol is transmitted for at least one of information transmission through non-coherent detection, channel estimation, and radar sensing.

7. In claim 1, A method in which the above constellation is selected based on the number of time resources and the number of spatial resources that can be assigned to one symbol among a plurality of available constellations.

8. In claim 1, The step of generating at least one symbol comprises: Step of generating a unit signal; applying an initial phase value for at least one symbol to the unit signal; and A method comprising the step of applying a phase shift vector for at least one symbol to the unit signal to which the initial phase value is applied.

9. In claim 8, The above initial phase value is applied by a quantized phase shifter.

10. In claim 8, The above phase shift vector is a method applied by an analog phase array.

11. In claim 1, The above rotation matrix is ​​a diagonal matrix.

12. In claim 1, A method in which the diagonal elements of the rotation matrix include the function values ​​of a discrete-domain complex exponential function having a period L, the domain of which is given as a feasible region for the decision variables.

13. In claim 12, The above period L is set to be equal to the number of constellation points.

14. In a device for transmitting a signal in a wireless communication system, Transmitter and receiver; and A processor connected to the above transmitter and receiver is included, The above processor, Generate bits of information, Generate at least one codeword by encoding information bits, Generating at least one symbol corresponding to at least a part of at least one codeword, Controlling to transmit at least one symbol, A device for generating at least one symbol, wherein a constellation is determined by optimizing decision variables that determine diagonal elements of a rotation matrix for a constellation design expressed as a product of an initial matrix and a rotation matrix based on a minimum pairwise distance between constellation points.

15. In communication devices, At least one processor; At least one computer memory connected to said at least one processor and storing instructions that direct operations when executed by said at least one processor, The above actions are, Step of generating information bits; A step of generating at least one codeword by encoding information bits; generating at least one symbol corresponding to at least a part of said at least one codeword; and comprising a step of transmitting at least one symbol, A communication device in which a constellation for generating at least one symbol is determined by optimizing decision variables that determine diagonal elements of a rotation matrix for a constellation design expressed as a product of an initial matrix and a rotation matrix based on a minimum pairwise distance between constellation points.

16. In a non-transitory computer-readable medium storing at least one instruction, comprising at least one instruction executable by the processor, At least one of the above commands causes the device to: Generate bits of information, Generate at least one codeword by encoding information bits, Generating at least one symbol corresponding to at least a part of at least one codeword, Controlling to transmit at least one symbol, A non-transitory computer-readable medium in which a constellation for generating at least one symbol is determined by optimizing decision variables that determine diagonal elements of a rotation matrix for a constellation design expressed as a product of an initial matrix and a rotation matrix based on a minimum pairwise distance between constellation points.

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