Apparatus and method for performing random access procedure in wireless communication system

Abstract

The purpose of the present disclosure is to perform a random access procedure in a wireless communication system, and an operation method performed by a user equipment comprises the steps of: receiving a paging message from a base station; transmitting a random access channel (RACH) preamble to the base station; receiving a random access response (RAR) message from the base station; transmitting a reference signal to the base station; and receiving a contention resolution message from the base station, wherein the paging message may include at least one of information related to a preamble index for the RACH preamble and information related to transmission power of the RACH preamble.

Description

Device and method for performing a random access procedure in a wireless communication system

[0001] The present disclosure relates to a wireless communication system, and to a device and method for performing a random access procedure 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, communication systems that consider reliability and latency-sensitive services / user equipment (UE) as well as massive machine type communications (mMTC), which connects numerous devices and objects to provide diverse services anytime and anywhere, are being proposed. Various technological configurations are being proposed for these solutions.

[0004] The present disclosure relates to a device and method for effectively performing a random access channel (RACH) procedure in a wireless communication system.

[0005] The present disclosure relates to a device and method for supporting an effective RACH procedure of a terminal receiving paging in a wireless communication system.

[0006] The present disclosure relates to a device and method for reducing the probability of contention for a RACH procedure of a terminal receiving paging in a wireless communication system.

[0007] The present disclosure relates to a device and method for providing information for reducing the probability of contention for a RACH procedure of a terminal receiving paging in a wireless communication system.

[0008] The present disclosure relates to a device and method for supporting a RACH procedure specialized for a terminal receiving paging in a wireless communication system.

[0009] The present disclosure relates to a device and method for allocating a dedicated RACH preamble for a terminal receiving paging in a wireless communication system.

[0010] The present disclosure relates to a device and method for distinguishing between a paged terminal and another terminal based on a RACH preamble in a wireless communication system.

[0011] The present disclosure relates to a device and method for controlling a paged terminal to transmit a RACH preamble with higher transmission power than other terminals in a wireless communication system.

[0012] The present disclosure relates to a device and method for determining a preamble index and transmission power of a RACH preamble for a terminal receiving paging in a wireless communication system.

[0013] The present disclosure relates to a device and method for supporting a dedicated DCI (downlink control information) format for a terminal receiving paging in a wireless communication system.

[0014] The present disclosure relates to a device and method for controlling a paged terminal to transmit a reference signal to resolve contention in a wireless communication system.

[0015] The technical objectives to be achieved in the present disclosure are not limited to those mentioned above, and other technical tasks not mentioned can be considered by a person having ordinary skill in the technical field to which the technical configuration of the present disclosure is applied from the embodiments of the present disclosure described below.

[0016] As an example of the present disclosure, an operation method performed by a terminal in a wireless communication system includes the steps of receiving a paging message from a base station, transmitting a random access channel (RACH) preamble to the base station, receiving a random access response (RAR) message from the base station, transmitting a reference signal to the base station, and receiving a contention resolution message from the base station, wherein the paging message may include at least one of information related to a preamble index for the RACH preamble or information related to transmission power of the RACH preamble.

[0017] As an example of the present disclosure, an operation method performed by a base station in a wireless communication system includes the steps of transmitting a paging message to a terminal, receiving a RACH (random access channel) preamble from the terminal, transmitting a RAR (random access response) message to the terminal, receiving a reference signal from the terminal, and transmitting a contention resolution message to the terminal, wherein the paging message may include at least one of information related to a preamble index for the RACH preamble or information related to transmission power of the RACH preamble.

[0018] As an example of the present disclosure, in a communication system, a terminal includes a transceiver and a processor connected to the transceiver, wherein the processor is configured to receive a paging message from a base station, transmit a random access channel (RACH) preamble to the base station, receive a random access response (RAR) message from the base station, transmit a reference signal to the base station, and receive a contention resolution message from the base station, wherein the paging message may include at least one of information related to a preamble index for the RACH preamble or information related to a transmission power of the RACH preamble.

[0019] As an example of the present disclosure, in a communication system, a base station includes a transceiver and a processor connected to the transceiver, wherein the processor is configured to transmit a paging message to a terminal, receive a random access channel (RACH) preamble from the terminal, transmit a random access response (RAR) message to the terminal, receive a reference signal from the terminal, and transmit a contention resolution message to the terminal, wherein the paging message may include at least one of information related to a preamble index for the RACH preamble or information related to transmission power of the RACH preamble.

[0020] 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, the operations including: receiving a paging message from a base station, transmitting a random access channel (RACH) preamble to the base station, receiving a random access response (RAR) message from the base station, transmitting a reference signal to the base station, and receiving a contention resolution message from the base station, wherein the paging message may include at least one of information related to a preamble index for the RACH preamble or information related to a transmission power of the RACH preamble.

[0021] 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, wherein the at least one instruction instructs a device to receive a paging message from a base station, transmit a random access channel (RACH) preamble to the base station, receive a random access response (RAR) message from the base station, transmit a reference signal to the base station, and receive a contention resolution message from the base station, wherein the paging message may include at least one of information related to a preamble index for the RACH preamble or information related to a transmit power of the RACH preamble.

[0022] 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.

[0023] The following effects may be achieved by embodiments based on the present disclosure.

[0024] According to the present disclosure, a paged terminal can quickly establish a connection.

[0025] 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.

[0026] 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.

[0027] Figure 1 illustrates an example of a communication system applicable to the present disclosure.

[0028] FIG. 3 illustrates an example of a wireless device applicable to the present disclosure.

[0029] FIG. 3 illustrates a method for processing a transmission signal applicable to the present disclosure.

[0030] FIG. 4 illustrates an example of a communication structure that can be provided in a 6G (6th generation) system applicable to the present disclosure.

[0031] Figure 4 illustrates a communication procedure between a terminal and a base station applicable to the present disclosure.

[0032] FIG. 5 illustrates an example of a communication structure that can be provided in a 6G (6th generation) system applicable to the present disclosure.

[0033] Figure 6 illustrates an electromagnetic spectrum applicable to the present disclosure.

[0034] Figure 7 illustrates a THz communication method applicable to the present disclosure.

[0035] Figure 8 illustrates a THz signal generation method applicable to the present disclosure.

[0036] FIG. 9 illustrates a wireless communication transceiver applicable to the present disclosure.

[0037] Figure 10 illustrates a transmitter structure applicable to the present disclosure.

[0038] Figure 11 illustrates a system information transmission procedure applicable to the present disclosure.

[0039] Figure 12 illustrates a beam management procedure applicable to the present disclosure.

[0040] Figure 13 illustrates an example of a beam width based on half power beam width (HPBW) applicable to the present disclosure.

[0041] FIG. 14a and FIG. 14b illustrate reception examples of SSB (synchronization signal / physical broadcasting channel block) and paging applicable to the present disclosure.

[0042] FIG. 15 illustrates an example of a procedure for performing a random access channel (RACH) procedure in response to paging according to one embodiment of the present disclosure.

[0043] FIG. 16 illustrates an example of a procedure for performing a RACH procedure with a paged terminal according to one embodiment of the present disclosure.

[0044] FIG. 17 illustrates an example of a procedure for transmitting a RACH preamble in response to paging according to one embodiment of the present disclosure.

[0045] FIG. 18 illustrates an example of a procedure for transmitting a reference signal based on paging according to one embodiment of the present disclosure.

[0046] FIG. 19A illustrates examples of a RACH procedure for a paged terminal according to one embodiment of the present disclosure.

[0047] FIG. 19b illustrates examples of a RACH procedure for a paged terminal according to one embodiment of the present disclosure.

[0048] FIG. 20 shows an example of a detection result of a reference signal transmitted by three terminals according to one embodiment of the present disclosure.

[0049] FIG. 21a and FIG. 21b show examples of detection results of reference signals transmitted by five terminals according to one embodiment of the present disclosure.

[0050] FIG. 22 illustrates examples of messages and signals transmitted in a RACH procedure according to one embodiment of the present disclosure.

[0051] Figure 23 illustrates an example of a wireless device applicable to the present disclosure.

[0052] Figure 24 illustrates an example of a portable device applicable to the present disclosure.

[0053] FIG. 25 illustrates an example of a vehicle or autonomous vehicle applicable to the present disclosure.

[0054] Figure 26 illustrates an example of a vehicle applicable to the present disclosure.

[0055] FIG. 27 illustrates an example of an XR device applicable to the present disclosure.

[0056] Figure 28 illustrates an example of a robot applicable to the present disclosure.

[0057] Figure 29 illustrates an example of an AI device applicable to the present disclosure.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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).

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] Additionally, specific terms used in the embodiments of the present disclosure are provided to aid in understanding of the present disclosure, and the use of such specific terms may be changed to other forms without departing from the technical spirit of the present disclosure.

[0070] 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).

[0071] For clarity, the following description is based on 3GPP communication systems (e.g., LTE, NR, etc.), but the technical spirit of the present disclosure is not limited thereto. LTE may refer to technology after 3GPP TS 36.xxx Release 8. Specifically, LTE technology after 3GPP TS 36.xxx Release 10 may be referred to as LTE-A, and LTE technology after 3GPP TS 36.xxx Release 13 may be referred to as LTE-A pro. 3GPP NR may refer to technology after TS 38.xxx Release 15. 3GPP 6G may refer to technology after TS Release 17 and / or Release 18. "xxx" refers to a standard document detail number. LTE / NR / 6G may be collectively referred to as a 3GPP system.

[0072] For background information, terms, abbreviations, etc. used in this disclosure, reference may be made to standard documents published prior to this disclosure. For example, reference may be made to standard documents 36.xxx and 38.xxx.

[0073] Communication system applicable to the present disclosure

[0074] 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.

[0075] 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.

[0076] Figure 1 illustrates an example of a communication system applied to the present disclosure.

[0077] 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.

[0078] 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).

[0079] Wireless communication / connection (150a, 150b, 150c) can be established between wireless devices (100a to 100f) / base stations (120), 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.

[0080]

[0081] Devices applicable to the present disclosure

[0082] FIG. 2 illustrates an example of a wireless device applicable to the present disclosure.

[0083] 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).

[0084] 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.

[0085] 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.

[0086] At least one processor (202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. The at least one processor (202) may be implemented by hardware, firmware, software, or a combination thereof. For example, at least one application specific integrated circuit (ASIC), at least one digital signal processor (DSP), at least one digital signal processing device (DSPD), at least one programmable logic device (PLD), or at least one field programmable gate array (FPGA) may be included in the at least one processor (202). The descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. The descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document may be included in the at least one processor (202), or may be stored in at least one memory (204) and executed by the at least one processor (202). The descriptions, functions, procedures, suggestions, methods and / or flowcharts disclosed in this document may be implemented using firmware or software in the form of code, instructions and / or sets of instructions.

[0087] 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.

[0088] 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.

[0089] 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).

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] The codeword can be converted into a wireless signal through the signal processing circuit (300) of FIG. 3. Here, the codeword is an encoded bit sequence of an information block. The information block may include a transport block (e.g., a UL-SCH transport block, a DL-SCH transport block). Here, the information block may include data related to AI (e.g., training data, AI model data, input data, output data, etc.), and the codeword may be an encoded bit sequence corresponding to the data related to AI. The wireless signal may be transmitted through various physical channels (e.g., PUSCH, PDSCH). Specifically, the codeword may be converted into a bit sequence scrambled by a scrambler (310). The scramble sequence used for scrambling is generated based on an initialization value, and the initialization value may include ID information of the wireless device, etc. The scrambled bit sequence may be modulated into a modulation symbol sequence by a modulator (320). Modulation schemes may include pi / 2-BPSK (pi / 2-binary phase shift keying), m-PSK (m-phase shift keying), m-QAM (m-quadrature amplitude modulation), etc.

[0099] A complex modulation symbol sequence can be mapped to at least one transport layer by a layer mapper (330). Here, a transport layer is a logical resource unit for mapping a signal or data transmitted through spatial resources to antenna ports, and one transport layer can correspond to one stream or one antenna port. Each of the complex modulation symbols included in the complex modulation symbol sequence is mapped to at least one transport layer, thereby determining which antenna port it will be transmitted through. The modulation symbols of each transport layer can be mapped to the corresponding antenna port(s) by a precoder (340). The output z of the precoder (340) can be obtained by multiplying the output y of the layer mapper (330) by a precoding matrix W of NХM. Here, N is the number of antenna ports, and M is the number of transport layers. Here, the precoder (340) may perform precoding after performing transform precoding (e.g., discrete Fourier transform (DFT) transform) on complex modulation symbols. Additionally, the precoder (340) may perform precoding without performing transform precoding.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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).

[0104] In step 403, the terminal (410) obtains system information transmitted from the base station (420). The system information is information related to the properties, characteristics, and / or capabilities of the base station (420) required to access the base station (420) and use the service, and may be classified by content (e.g., whether it is essential for access), transmission structure (e.g., channel used, whether provided on-demand), etc., and may be classified into, for example, a master information block (MIB) and a system information block (SIB). If necessary, the terminal (410) may transmit a signal requesting system information before receiving the system information. The system information may include information related to an AI function. For example, the system information may include at least one of information related to an AI model, information related to training, and information related to inference / prediction, as information required for operations performed based on AI. However, the request and provision of the system information may be performed after a random access procedure described below.

[0105] 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.

[0106] In step 407, the terminal (410) and the base station (420) perform signaling of control information. Here, the control information may be defined in various layers, such as a layer that controls a connection (e.g., a radio resource control (RRC) layer), a layer that handles mapping between logical channels and transport channels (e.g., a media access control (MAC) layer), and a layer that handles physical channels (e.g., a physical (PHY) layer). For example, the terminal (410) and the base station (420) may perform at least one of signaling for establishing a connection, signaling for determining settings related to communication, and signaling for indicating allocated resources. In addition, the signaling of the control information may be performed to convey information related to an AI function. For example, the information related to an AI function is information necessary for an operation performed based on AI, and may include at least one of information related to an AI model, information related to training, and information related to inference / prediction. More specifically, information related to the AI ​​function signaled in step 407 may be combined and / or linked with information related to the AI ​​function signaled in step 403, and the two may be defined in a hierarchical, mutually complementary, or substitutive structure.

[0107] In step 409, the terminal (410) and the base station (420) transmit and / or receive data. In other words, the terminal (410) and the base station (420) can process, transmit, and / or receive data based on the signaling of the control information. For example, when transmitting data, the terminal (410) or the base station (420) can perform at least one of channel encoding, rate matching, scrambling, constellation mapping, layer mapping, waveform modulation, antenna mapping, and resource mapping on the information bits. Conversely, when receiving data, the terminal (410) or the base station (420) can perform at least one of signal extraction from resources, waveform demodulation for each antenna, signal arrangement considering layer mapping, constellation demapping, descrambling, and channel decoding. Here, the transmitted data is data related to AI, and may include, for example, data for AI-based operations or data generated by AI-based operations.

[0108] Steps 401 to 409 illustrated with reference to FIG. 4 do not necessarily have to be performed in the order illustrated in FIG. 4, and the order of at least some of the steps may vary. Furthermore, at least some of steps 401 to 409 may be combined into a single step or omitted. That is, the steps illustrated in FIG. 4 may be performed in various modified forms.

[0109] 6G communication systems and core implementation technologies of 6G systems

[0110] 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.

[0111] 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.

[0112] Per device peak data rate1 TbpsE2E latency1 msMaximum spectral efficiency100 bps / HzMobility supportup to 1000 km / hrSatellite integrationFullyAIFullyAutonomous vehicleFullyXRFullyHaptic CommunicationFully

[0113] At this time, the 6G system may have key factors such as enhanced mobile broadband (eMBB), ultra-reliable low latency communications (URLLC), massive machine type communications (mMTC), AI integrated communication, tactile internet, high throughput, high network capacity, high energy efficiency, low backhaul and access network congestion, and enhanced data security. FIG. 5 illustrates an example of a communication structure that can be provided in a 6G system applicable to the present disclosure. Referring to FIG. 5, the 6G system is expected to have simultaneous wireless communication connectivity that is 50 times higher than that of a 5G wireless communication system. URLLC, a key feature of 5G, is expected to become an even more crucial technology in 6G communications, offering end-to-end latency of less than 1 ms. Furthermore, 6G systems will boast significantly higher volumetric spectral efficiency than the commonly used area spectral efficiency. 6G systems can offer extremely long battery life and advanced battery technologies for energy harvesting, eliminating the need for separate charging for mobile devices in 6G systems. New network characteristics in 6G may include:

[0114] - Satellite integrated network: 6G is expected to integrate with satellites to provide a global mobile network. The integration of terrestrial, satellite, and airborne networks into a single wireless communications system is crucial for 6G.

[0115] Connected Intelligence: Unlike previous generations of wireless communication systems, 6G is revolutionary, upgrading the wireless evolution from "connected objects" to "connected intelligence." AI can be applied at every stage of the communication process (or at every signal processing step, as described below).

[0116] - Seamless integration of wireless information and energy transfer: 6G wireless networks will transfer power to charge the batteries of devices such as smartphones and sensors. Therefore, wireless information and energy transfer (WIET) will be integrated.

[0117] - Ubiquitous super 3D connectivity: Access to networks and core network functions of drones and very low Earth orbit satellites will create super 3D connectivity in 6G ubiquitous.

[0118] Some general requirements for the new network characteristics of 6G, such as the above, may be as follows:

[0119] - Small cell networks: The concept of small cell networks was introduced to improve received signal quality in cellular systems by increasing throughput, energy efficiency, and spectral efficiency. Consequently, small cell networks are essential for 5G and beyond-5G (5GB) communication systems. Accordingly, 6G communication systems also adopt the characteristics of small cell networks.

[0120] Ultra-dense heterogeneous networks: Ultra-dense heterogeneous networks will be another key feature of 6G communication systems. Multi-tier networks comprised of heterogeneous networks improve overall QoS and reduce costs.

[0121] High-capacity backhaul: Backhaul connections are characterized by high-capacity backhaul networks to support high-volume traffic. High-speed fiber optics and free-space optics (FSO) systems may be potential solutions to this problem.

[0122] - Radar technology integrated with mobile technology: High-precision localization (or location-based services) through communications is a key feature of 6G wireless communication systems. Therefore, radar systems will be integrated with 6G networks.

[0123] - Softwarization and virtualization: Softwarization and virtualization are two critical features that form the foundation of the design process for 5GB networks to ensure flexibility, reconfigurability, and programmability. Furthermore, billions of devices can be shared on a shared physical infrastructure.

[0124] To satisfy the above-mentioned characteristics, the core implementation technologies of the 6G system may include artificial intelligence (AI), THz (terahertz) communication, optical wireless technology, FSO backhaul network, massive MIMO technology, blockchain, 3D networking, quantum communication, unmanned aerial vehicles, cell-free communication, wireless information and energy transfer (WIET), integration of sensing and communication, integration of access backhaul networks, holographic beamforming, big data analysis, and large intelligent surface (LIS).

[0125] For example, THz communication can be utilized in 6G systems. THz communication is a communication that utilizes a spectrum in a frequency band between 0.3 THz and 3 THz with a corresponding wavelength in the range of 0.1 mm to 1 mm, as shown in FIG. 6. Referring to FIG. 6, the frequency band of THz waves is located in the middle region between the infrared band and the millimeter wave band, and therefore, THz waves can be understood as radio waves with the shortest wavelength and light waves with the longest wavelength. Therefore, THz waves share some of the characteristics of infrared and microwave waves, and specifically, they can simultaneously have the transparency of electromagnetic waves and the straightness of light waves.

[0126] 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.

[0127] In addition, since the photon energy of THz waves is only a few meV, it has the characteristic of being harmless to the human body. The frequency band expected to be used for THz wireless communication may be the D-band (110 GHz to 170 GHz) or H-band (220 GHz to 325 GHz) bands where propagation loss due to absorption of molecules in the air is small. In addition to 3GPP, standardization discussions for THz wireless communication are being centered around the IEEE 802.15 THz WG (working group), and standard documents issued by the IEEE 802.15 TG (task group) (e.g., TG3d, TG3e) can specify or supplement the contents described in this specification. THz wireless communication can be applied to wireless cognition, sensing, imaging, wireless communication, THz navigation, etc.

[0128] 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.

[0129] 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

[0130] FIG. 8 illustrates a THz signal generation method applicable to the present disclosure. FIG. 9 also illustrates a wireless communication transceiver applicable to the present disclosure. Referring to FIGS. 8 and 9, the optical device-based THz wireless communication technology refers to a method of generating and modulating a THz signal using an optical device. The optical device-based THz signal generation technology is a technology that generates an ultra-high-speed optical signal using a laser and an optical modulator, and converts it into a THz signal using an ultra-high-speed photodetector. Compared to a technology that uses only electronic devices, this technology makes it easy to increase the frequency, enables high-power signal generation, and obtains a flat response characteristic over a wide frequency band. For the optical device-based THz signal generation, as illustrated in FIG. 8, a laser diode, a wideband optical modulator, and an ultra-high-speed photodetector are required. In the case of FIG. 8, light signals from two lasers with different wavelengths are combined to generate a THz signal corresponding to the wavelength difference between the lasers. In Fig. 8, an optical coupler refers to a semiconductor device that transmits an electrical signal using optical waves to provide electrical isolation and coupling between circuits or systems, and a uni-travelling carrier photo-detector (UTC-PD) is a type of photodetector that uses electrons as active carriers and reduces the travel time of electrons through bandgap grading. The UTC-PD is capable of photodetection at 150 GHz or higher.In Fig. 9, EDFA (erbium-doped fiber amplifier) ​​represents an erbium-doped fiber amplifier, PD (photo detector) represents a semiconductor device that can convert an optical signal into an electrical signal, OSA represents an optical module (optical sub assembly) that modularizes various optical communication functions (e.g., photoelectric conversion, electro-optical conversion, etc.) into a single component, and DSO represents a digital storage oscilloscope.

[0131] Figure 10 illustrates a transmitter structure applicable to the present disclosure.

[0132] Referring to Figure 10, in order to modulate data into an optical signal, an optical source such as a laser can be passed through an optical wave guide to change the phase of the signal, etc. At this time, data is loaded by changing the electrical characteristics through a microwave contact, etc. Therefore, the optical modulator output is formed as a modulated waveform.

[0133] Data may be provided from a data signal generator. Here, the data may include various user data, configuration information, control information, etc. transmitted through a channel. Furthermore, the data may include data related to AI-based operations, such as information for configuring an AI model, input / output data for tasks of the AI ​​model, etc. To this end, components related to AI functions (e.g., an AI processing unit) may be included in the data signal generator or may be linked to the data signal generator.

[0134] An optical / electronic converter (O / E converter) can generate THz pulses by optical rectification using a nonlinear crystal, photoelectric conversion using a photoconductive antenna, or emission from a bunch of relativistic electrons. The THz pulse generated in the above manner can have a length in the range of femtoseconds to picoseconds. The optical / electronic converter (O / E converter) performs down conversion by utilizing the nonlinearity of the device.

[0135] Considering the THz spectrum usage, it is likely that multiple contiguous GHz bands will be used for THz systems, either fixed or for mobile services. For an outdoor scenario, the available bandwidth can be categorized based on an oxygen attenuation of 10^2 dB / km in the spectrum up to 1 THz. Accordingly, a framework in which the available bandwidth is divided into multiple band chunks can be considered. As an example of this framework, if the THz pulse length for a single carrier is set to 50 ps, ​​the bandwidth (BW) becomes approximately 20 GHz.

[0136] Effective down-conversion from the infrared band to the THz band depends on how to utilize the nonlinearity of the optical / electrical converter (O / E converter). In other words, to down-convert to the desired THz band, it is necessary to design an O / E converter with the most ideal non-linearity for transferring to the THz band. If an O / E converter that is not suitable for the target frequency band is used, errors in the amplitude and phase of the pulse are likely to occur.

[0137] A THz transmission and reception system can be implemented using a single optical-to-electrical converter in a single-carrier system. Depending on the channel environment, optical-to-electrical converters may be required as many as the number of carriers in a multi-carrier system. This phenomenon will be particularly noticeable in a multi-carrier system that utilizes multiple broadbands according to the aforementioned spectrum usage plan. In this regard, a frame structure for the multi-carrier system may be considered. A signal down-frequency converted based on an optical-to-electrical converter may be transmitted in a specific resource region (e.g., a specific frame). The frequency region of the specific resource region may include multiple chunks. Each chunk may be composed of at least one component carrier (CC).

[0138] Transmitting system information (e.g., MIB) in the THz frequency band can be inefficient because the beam width becomes narrower in high-frequency bands, requiring more beam sweeps to cover the entire cell area. This method of transmitting system information is particularly inefficient when there are only a few users within the cell. Accordingly, a system information transmission procedure, such as that illustrated in FIG. 11, may be employed.

[0139] Figure 11 illustrates a system information transmission procedure applicable to the present disclosure. Figure 11 illustrates an example of a procedure for transmitting system information for THz communication. The procedure illustrated in Figure 11 can be combined with various embodiments of the present disclosure described below. For example, the embodiments described below can be performed based on the system information acquired by the procedure illustrated in Figure 11. As another example, information and / or data transmitted in the procedure illustrated in Figure 11 can be generated and / or processed according to the embodiments described below.

[0140] Referring to FIG. 11, in step 1101, the base station (1120) transmits system information of cell #1 through cell #2. That is, the base station (1120) provides at least two cells, cell #1 uses a THz frequency band, and cell #2 uses a frequency band other than the THz frequency band. Here, the system information may include at least one of an SFN, a PDCCH configuration for SIB1, cell barring, cell re-selection, and subcarrier spacing generated in a higher layer, and may include at least one of an SFN, a half frame indicator, and an SSB (synchronization signal / physical broadcasting channel block) index generated in a physical layer. For this purpose, as an example, cell #1 and cell #2 may have a relationship of a secondary cell and a primary cell.

[0141] In step 1103, UE (1110) acquires synchronization for cell #1. Synchronization can be acquired by detecting a synchronization signal. Typically, synchronization is acquired before receiving system information. However, since system information for cell #1 is received from cell #2, synchronization acquisition for cell #1 can be performed after receiving the system information. For example, UE (1110) can acquire synchronization based on system information. However, unlike FIG. 11, in another example, synchronization acquisition can be performed before step 1101.

[0142] In step 1105, UE (1110) transmits a signal for accessing cell #1. For example, the signal may include a random access preamble. The structure of the signal and the resources (e.g., channels) for transmitting the signal can be identified through system information. Thereafter, in step 1107, UE (1110) and base station (1120) perform an access procedure for cell #1 and communicate. In this step, operations according to various embodiments described below may be performed.

[0143] The procedure described with reference to FIG. 11 may be performed when UE (1101) first connects to cell #1 of base station (1120). Alternatively, a similar procedure may be performed when UE (1101) hands over to cell #1 of base station (1120). However, in the case of handover, system information of cell #1 may be received from a cell of a base station other than cell #2 of base station (1120).

[0144] Communications in the THz band are expected to experience extremely severe path loss, and to overcome this, terminals and base stations must use extremely sharp beams. The use of sharp beams means that terminals and base stations must perform beam control in addition to beamforming, and the number of beams used increases significantly. Consequently, it takes a very long time to align the transmit and receive beams between the base station and terminals. Furthermore, if the beam alignment between the base station and terminals is misaligned due to the movement or movement of the terminals, frequent re-alignment of the beams is required, which can lead to link instability. Accordingly, a beam management procedure, as illustrated in FIG. 12 below, may be used.

[0145] FIG. 12 illustrates a beam management procedure applicable to the present disclosure. FIG. 12 illustrates an example of a procedure for searching and / or selecting beams for THz communication. The procedure illustrated in FIG. 12 may be combined with various embodiments of the present disclosure described below. For example, the embodiments described below may be performed using at least one beam acquired by the procedure illustrated in FIG. 11. As another example, information and / or data transmitted in the procedure illustrated in FIG. 12 may be generated and / or processed according to the embodiments described below. Herein, a beam may be referred to as a 'spatial domain filter', a 'spatial domain transmit filter', a 'spatial domain receive filter', and other terms having equivalent technical meanings thereto.

[0146] Referring to FIG. 12, in step 1201, a base station (1220) configures resources for beam management. Here, the resources may include at least one of time-frequency resources, channels, and spatial resources (e.g., antenna ports). For example, the base station (1220) may utilize a beam search signal (BSS) that is transmitted spatially separated from an existing downlink signal / channel for beam search. Here, the BSS may be transmitted based on a dedicated port for beam search. The dedicated port may be a different port from a port for transmitting an existing downlink signal / channel (e.g., SSB, PDSCH, etc.). BSS is a term defined for convenience of explanation, and the technical concept according to the present embodiment is not limited to the term BSS itself. That is, a signal transmitted based on a dedicated port defined / configured for beam search may be included in the technical concept according to the present embodiment.

[0147] In step 1203, the base station (1201) transmits measurement signals using multiple transmission beams. For example, the measurement signals may include at least one of a reference signal and a synchronization signal. At this time, the measurement signals may be transmitted as many times as the number of beams that require measurement, and may be transmitted in a multi-beam transmission method that forms multiple beams simultaneously to reduce sweeping time. Here, the multi-beam transmission may be performed based on at least one of a multi-panel, a sub-array, and a true time delay (TTD).

[0148] In step 1205, the UE (1210) transmits a feedback signal to the base station (1220). The feedback signal indicates at least one beam selected by the UE (1210). The UE (1210) may select at least one preferred beam based on the measurement signals received in step 1203. In step 1207, the UE (1210) and the base station (1220) perform communication. At this time, the UE (1210) and the base station (1220) may perform communication using the beam selected in step 1205. If channel reciprocity is established, the transmission beam of the UE (1210) may also be determined through steps 1203 and 1205, and thus, the transmission operation of the UE (1210) may also be performed using the beam selected in step 1205. If channel reciprocity is not established, a procedure including transmitting measurement signals of the UE (1210) and transmitting feedback signals of the base station (1220) may be performed to determine the transmission beam of the UE (1210). In step 1207, operations according to various embodiments described below may be performed.

[0149]

[0150] Specific embodiments of the present disclosure

[0151] The present disclosure relates to beam management in a wireless communication system, and more particularly, to a technique for performing beam recovery. More specifically, the present disclosure proposes a technique for enabling a paged terminal to transition to an RRC connected state more quickly by minimizing contention resolution and utilizing a 3-step RACH procedure that is a modification of the existing 4-step RACH procedure. In particular, the present disclosure proposes a technique for efficiently restoring a beam in case of beam loss in a situation where a serving beam SSB preceding paging is attempted to be received after deep sleep in an RRC idle state. In the present disclosure, receiving paging means receiving a paging signal or a paging message.

[0152] Radio waves experience path loss as they pass through a wireless channel. Path loss can be expressed as Pathloss = FreeSpacePathLoss + 10log(d) + AT[dB] + shadow fading. Here, FreeSpacePathLoss increases as the center frequency (i.e., the frequency used) increases, and it can also increase as the distance increases. It is widely known that THz communication is more susceptible to path loss than mmWave or LTE. In wireless communication environments with high propagation path loss, one solution to overcome path loss is to configure the transmitter and / or receiver with a large number of antenna elements and maximize beam gain. While highly direct antenna elements on a single antenna panel provide the effect of maximizing beam gain, they also result in a narrow beamwidth. The beamwidth is typically determined based on the half-power beamwidth (HPBW), which is defined as shown in Figure 13. Fig. 13 illustrates an example of a beamwidth based on HPBW applicable to the present disclosure. Referring to Fig. 13, the angle formed by two lines (1302, 1304) determined based on a power 3 dB lower than the peak gain can be determined as the beamwidth. HPBW can be determined as shown in the following [Mathematical Formula 1].

[0153]

[0154] In [Equation 1], is the frequency number, The number of silver antennas, is the antenna spacing, refers to the beam's directivity angle.

[0155] After the initial cell search, if the terminal does not transmit and / or receive UL / DL data, it may enter a deep sleep state to save power. At this time, the terminal transitions to the RRC idle state or inactive state. Here, in the inactive state, the RRC connection may be released. If the base station wants to transmit data to the terminal, since the connection with the terminal is in a released state, the terminal may be controlled to transition to a connected state by transmitting a signal for a specific purpose. At this time, a paging signal message may be used as the signal for a specific purpose. The cycle for receiving paging may depend on the parameter pagingCycle. Here, PagingCycle ::= ENUMERATED {rf32(320ms), rf64(640ms), rf128(1280ms), rf256(2560ms)} may be defined as follows.

[0156] Figures 14a and 14b illustrate examples of SSB and paging reception applicable to the present disclosure. Referring to Figures 14a and 14b, before receiving paging, the terminal receives SSB for synchronization and adaptive gain control (AGC). The SINR is determined by measuring the SSB three SSB intervals before receiving a paging occasion (1412 or 1422). Thereafter, as shown in Figure 14a, in a low SINR environment, the terminal can expect time diversity gain by receiving SSBs sequentially. As shown in Figure 14b, in a high SINR environment, the terminal can wake up in an interval including a paging occasion (1422) after a deep sleep.

[0157] Here, the section receiving the paging may be referred to as a paging frame. Multiple paging opportunities may exist within the paging frame. The reason why multiple paging opportunities exist is because the paging signal is transmitted in a TDD manner depending on the number of beams. When multiple paging opportunities are configured, SearchSpaceID may be set to a value greater than or equal to 0. The number of paging opportunities is determined as S*X, where S is the number of actually transmitted SSBs determined by SSB-related parameters (e.g., ssb-PositionsInBurst) in system information (e.g., SIB1), and X represents a PDCCH monitoring opportunity for paging per SSB. X is a value set by a higher layer configuration parameter (e.g., nrofPDCCH-MonitoringOccasionPerSSB-InPO), and may be determined to 1 if not set by a higher layer. The combination of S and X values ​​means that a paging signal can be transmitted using multiple narrow beams within a single wide beam for transmitting SSB. A terminal that receives paging can perform a 4-step RACH procedure to switch to an RRC connected state, and can perform an RRC establishment procedure for switching from an RRC idle state to an RRC connected state or an RRC resume procedure for switching from an RRC inactive state to an RRC connected state.

[0158] As described above, a terminal receiving a paging signal in the RRC idle state requires a rapid transition to the RRC connected state to receive downlink data from the base station. To enter the RRC connected state, an RRC establishment procedure must be performed first. According to the current standard, the RRC establishment procedure can be performed based on a four-step RACH. Furthermore, since RACH opportunities containing the same resources are shared by terminals performing initial cell search and terminals being paged, the RACH procedure operates on a contention basis. Due to contention, time delays may occur due to RACH retransmissions. Therefore, the present disclosure proposes a technique for reducing contention resolution to reduce additional delay for the paged terminal.

[0159] FIG. 15 illustrates an example of a procedure for performing a RACH procedure in response to paging according to one embodiment of the present disclosure. FIG. 15 illustrates a method performed by a terminal.

[0160] Referring to FIG. 15, in step S1501, the terminal receives a paging message. Although not illustrated in FIG. 15, the terminal may enter an RRC idle state or an inactive state under the control of the base station. While operating in the RRC idle state or inactive state, the terminal may receive a paging message from the base station. The paging message is a signaling to the terminal to switch to a connected mode in response to the occurrence of data to be transmitted to the terminal. According to various embodiments of the present disclosure, the paging message may include information related to a subsequent random access procedure. For example, the paging message may include at least one of information related to a RACH preamble (e.g., information related to a sequence index, power, etc.), information related to a reference signal based on paging, and information related to scrambling of DCI for a subsequently received RAR.

[0161] In step S1503, the terminal transmits a preamble. The preamble is an uplink physical layer signal transmitted via the RACH for a random access procedure, i.e., the RACH procedure. At this time, according to various embodiments of the present disclosure, the terminal may transmit a dedicated preamble allocated from a base station. In other words, the terminal may transmit a RACH preamble including a sequence corresponding to a preamble index provided by the base station. Furthermore, according to various embodiments of the present disclosure, the terminal may calculate and apply the transmission power of the RACH preamble based on parameters related to the power provided by the base station.

[0162] In step S1505, the terminal receives an RAR. To receive the RAR, the terminal may receive a DCI including scheduling information for the RAR and may receive the RAR through a resource indicated by the DCI. At this time, according to one embodiment of the present disclosure, the DCI may be a DCI designed exclusively for the paged terminal, i.e., may have a dedicated format. According to one embodiment, the DCI may further include scheduling information for a reference signal to be transmitted later. The terminal may determine whether to perform subsequent steps based on whether the decoding of the RAR is successful. If the decoding of the RAR fails, the terminal may retransmit the RACH preamble, although not illustrated in FIG. 15 .

[0163] In step S1507, the terminal transmits a reference signal. Here, the reference signal is used in the RACH procedure initiated in response to paging, and is transmitted as a signal replacing MSG-3 during the RACH procedure. The terminal may transmit the reference signal based on the DCI including scheduling information for the RAR. That is, the DCI including scheduling information for the RAR may further include scheduling information for the reference signal. In addition, the terminal may select a sequence for the reference signal based on the RACH preamble transmitted in step S1503, and transmit the reference signal based on the selected sequence. In some cases, the reference signal may be transmitted in an overlapping manner on the same resource as the reference signal of another terminal. Furthermore, according to another embodiment, the terminal may transmit a message together with the reference signal through the allocated resource. Here, the reference signal is a signal requesting connection establishment in the RACH procedure, and is a signal including one sequence selected from a set of orthogonal or quasi-orthogonal sequences, and may be referred to by another name.

[0164] In step S1509, the terminal receives a contention resolution message. The contention resolution message serves as information for resolving contention and may include terminal identification information (e.g., UE contention resolution identity). According to various embodiments of the present disclosure, the contention resolution message may include information related to the reference signal transmitted in step S1507 (e.g., a sequence included in the reference signal, a portion of the sequence, or an index of the sequence). Accordingly, the terminal can determine the success or failure of the RACH procedure based on the contention resolution message.

[0165] FIG. 16 illustrates an example of a procedure for performing a RACH procedure with a paged terminal according to one embodiment of the present disclosure. FIG. 16 illustrates a method performed by a base station.

[0166] Referring to FIG. 16, in step S1601, the base station transmits a paging message. Although not illustrated in FIG. 16, the base station may control the terminal to operate in an RRC idle state or an inactive state, and then transmit a paging message when data to be transmitted to the terminal occurs while the terminal is operating in the RRC idle state or an inactive state. The paging message is a signal to the terminal to switch to a connected mode in response to the occurrence of data to be transmitted to the terminal. According to various embodiments of the present disclosure, the paging message may include information related to a subsequent random access procedure. For example, the paging message may include at least one of information related to a RACH preamble (e.g., information related to a sequence index, power, etc.), information related to a reference signal based on paging, and information related to scrambling of DCI for a subsequently received RAR.

[0167] In step S1603, the base station receives a preamble. The preamble is an uplink physical layer signal transmitted via the RACH for a random access procedure, i.e., the RACH procedure. At this time, according to various embodiments of the present disclosure, the received preamble may transmit a dedicated preamble allocated by the base station. In other words, the base station may receive and detect a RACH preamble including a sequence corresponding to the preamble index provided to the terminal in step S1601.

[0168] In step S1605, the base station transmits an RAR. To transmit the RAR, the base station may transmit a DCI including scheduling information for the RAR and transmit the RAR through a resource indicated by the DCI. At this time, according to one embodiment of the present disclosure, the DCI may be a DCI designed exclusively for the paged terminal, i.e., a DCI having a dedicated format. According to one embodiment, the DCI may further include scheduling information for a reference signal to be transmitted later. At this time, the base station may determine a downlink beam toward the terminal based on the preamble received in step S1603, and transmit the DCI and the RAR using the determined downlink beam.

[0169] In step S1607, the base station receives a reference signal. Here, the reference signal is used in a RACH procedure initiated in response to paging, and is received as a signal replacing MSG-3 during the RACH procedure. The reference signal may be received through a resource scheduled by a DCI including scheduling information for an RAR. That is, the DCI including scheduling information for an RAR may further include scheduling information for the reference signal. In addition, the base station may determine a sequence for the reference signal based on the RACH preamble received in step S1603, and identify and / or detect the reference signal. In some cases, the base station may receive reference signals of multiple terminals that are transmitted in an overlapping manner on the same resource. Here, the reference signal is a signal requesting connection establishment in the RACH procedure, and is a signal including one sequence selected from a set of orthogonal or quasi-orthogonal sequences, and may be referred to by another name.

[0170] In step S1609, the base station transmits a contention resolution message. The contention resolution message serves as information for resolving contention and may include terminal identification information (e.g., UE contention resolution identity). According to various embodiments of the present disclosure, the contention resolution message may include information related to the reference signal received in step S1607 (e.g., a sequence included in the reference signal, a portion of the sequence, or an index of the sequence).

[0171] FIG. 17 illustrates an example of a procedure for transmitting a RACH preamble in response to paging according to one embodiment of the present disclosure. FIG. 17 illustrates a method performed by a terminal.

[0172] Referring to FIG. 17, in step S1701, the terminal acquires information related to a paging-only preamble. The terminal can acquire information related to the paging-only preamble through configuration information and / or control information received from the base station. For example, the information related to the preamble can include an index of a preamble sequence included in the preamble, i.e., a preamble index. That is, the terminal can check the preamble index assigned to the terminal for a RACH procedure following paging. In addition, the information related to the paging-only preamble can include at least one parameter for determining the transmission power of the preamble. For example, the at least one parameter can include at least one of a target reception power value for the RACH preamble at the base station and an offset value for a power increase for retransmission.

[0173] In step S1703, the terminal transmits a preamble based on the acquired information. That is, the terminal can generate a preamble including a sequence corresponding to the acquired preamble index and transmit the generated preamble to the base station via the RACH. At this time, the terminal can determine the transmission power of the preamble based on at least one of a target reception power value and an offset value for a power increase for retransmission. Since the preamble index assigned by the base station is used, the probability of contention can be relatively reduced. In addition, the preamble index of the transmitted preamble can inform the base station that the terminal is a terminal performing a RACH procedure in response to paging.

[0174] FIG. 18 illustrates an example of a procedure for transmitting a reference signal based on paging according to one embodiment of the present disclosure. FIG. 18 illustrates a method performed by a terminal.

[0175] Referring to FIG. 18, in step S1801, the terminal acquires information related to scheduling of a paging-based reference signal. The paging-based reference signal is a signal transmitted after receiving an RAR in a RACH procedure corresponding to paging, and can be scheduled through signaling related to paging. For example, the information related to scheduling may include at least one of information related to resources and information related to the sequence of the reference signal. Here, if the information related to scheduling includes multiple parameters, the parameters may be signaled by one or more messages and / or signals.

[0176] In step S1803, the terminal transmits a reference signal based on the acquired information. The terminal can generate a reference signal sequence based on scheduling information, identify resources, and transmit the reference signal using the identified resources. At this time, the terminal can determine the uplink timing based on the TA command indicated by the previously received RAR, and transmit the reference signal based on the determined timing.

[0177] Figure 19a illustrates examples of a RACH procedure for a paged terminal according to one embodiment of the present disclosure. Figure 19a illustrates signal exchange between UEs (1910-1, 1910-2) and a base station (1920) for a RACH procedure performed based on paging. Here, the first UE (1910-1) is a paged UE, and the second UE (1910-2) is a normal UE. Figure 19a illustrates a case where the base station (1920) cannot distinguish between the RACH preambles transmitted by the first UE (1910-1) and the second UE (1910-2).

[0178] Referring to FIG. 19A, in step S1901, the base station (1920) transmits a paging message to the first UE (1910-1). The paging message may include preamble index information set to index #1 and power information set to 20 dB. Here, the preamble index information indicates the preamble index allocated to the first UE (1910-1) for the RACH procedure, and the power information is used to determine the transmission power of the RACH preamble.

[0179] In step S1903, the first UE (1910-1) transmits a RACH preamble to the base station (1920). Here, the RACH preamble includes a sequence corresponding to preamble index #1. Then, the first UE (1910-1) transmits the RACH preamble with a transmission power determined based on power information included in the paging message. In step S1905, the second UE (1910-2) transmits a RACH preamble to the base station (1920). The second UE (1910-2) may perform a RACH procedure for initial access, etc. Here, the RACH preamble transmitted by the second UE (1910-2) includes a sequence corresponding to a preamble index randomly selected by the second UE (1910-2). If the second UE (1910-2) does not select preamble index #1, the base station (1920) can determine that the RACH preamble is transmitted by the first UE (1910-1) based on the detected preamble index. On the other hand, if the second UE (1910-2) selects preamble index #1, the base station (1920) can determine that the RACH preamble is transmitted by the first UE (1910-1) based on the detected preamble index and the reception power. In the present embodiment, the second UE (1910-2) selects preamble index #1. In addition, the reception powers of the RACH preambles of the first UE (1910-1) and the second UE (1910-2) are not different enough to be distinguished. Accordingly, the base station (1920) cannot distinguish between RACH preambles and determines that only the first UE (1910-1) transmitted the RACH preamble.

[0180] In step S1907a, the base station (1920) transmits a paging DCI. The paging DCI may be a DCI having a format for a RACH procedure according to paging. In other words, the paging DCI may be a DCI designed exclusively for the paged terminal, i.e., may have a dedicated format. The paging DCI may be received by each of the first UE (1910-1) and the second UE (1910-2). However, since the paging DCI is scrambled using the dedicated RNTI transmitted to the first UE (1910-1), the second UE (1910-2) fails to decode the paging DCI. In step S1909, the base station (1920) transmits a RAR message. At this time, the RAR may be received by the first UE (1910-1).

[0181] At step S1911, the first UE (1910-1) transmits a reference signal for paging, i.e., a paging reference signal (PRES). That is, the first UE (1910-1) can transmit the PRES in response to the RAR message. At step S1917, the base station (1920) transmits MSG4 to the first UE (1910-1). The base station (1920) detects the PRES transmitted by the first UE (1910-1) and transmits a message for contention resolution to the first UE (1910-1).

[0182] FIG. 19B illustrates examples of a RACH procedure for a paged terminal according to one embodiment of the present disclosure. FIG. 19B illustrates signal exchange between UEs (1910-1, 1910-2) and a base station (1920) for a RACH procedure performed based on paging. Here, the first UE (1910-1) is a paged UE, and the second UE (1910-2) is a normal UE. FIG. 19B illustrates a case where the base station (1920) distinguishes between RACH preambles transmitted by the first UE (1910-1) and the second UE (1910-2).

[0183] Referring to FIG. 19b, in step S1901, the base station (1920) transmits a paging message to the first UE (1910-1). The paging message may include preamble index information set to index #1 and power information set to 20 dB. Here, the preamble index information indicates the preamble index allocated to the first UE (1910-1) for the RACH procedure, and the power information is used to determine the transmission power of the RACH preamble.

[0184] In step S1903, the first UE (1910-1) transmits a RACH preamble to the base station (1920). Here, the RACH preamble includes a sequence corresponding to preamble index #1. Then, the first UE (1910-1) transmits the RACH preamble with a transmission power determined based on power information included in the paging message. In step S1905, the second UE (1910-2) transmits a RACH preamble to the base station (1920). The second UE (1910-2) may perform a RACH procedure for initial access, etc. Here, the RACH preamble transmitted by the second UE (1910-2) includes a sequence corresponding to a preamble index randomly selected by the second UE (1910-2). If the second UE (1910-2) does not select preamble index #1, the base station (1920) can determine that the RACH preamble is transmitted by the first UE (1910-1) based on the detected preamble index. On the other hand, if the second UE (1910-2) selects preamble index #1, the base station (1920) can determine that the RACH preamble is transmitted by the first UE (1910-1) based on the detected preamble index and the reception power. In the present embodiment, the second UE (1910-2) selects an index other than preamble index #1, or the second UE (1910-2) selects preamble index #1, but the reception powers of the RACH preambles of the first UE (1910-1) and the second UE (1910-2) are different enough to be distinguishable. Accordingly, the base station (1920) distinguishes the RACH preambles and determines that the first UE (1910-1) and the second UE (1910-2) each transmitted a RACH preamble.

[0185] In step S1907b-1, the base station (1920) transmits a paging DCI to the first UE (1910-1). The paging DCI may be a DCI having a format for a RACH procedure according to paging. In other words, the paging DCI may be a DCI designed exclusively for the paged terminal, i.e., may have a dedicated format. In step S1907b-2, the base station (1920) transmits a DCI to the second UE (1910-2). The DCI may include scheduling information for an RAR message. In step S1909, the base station (1920) transmits an RAR message. At this time, the RAR may be received by each of the first UE (1910-1) and the second UE (1910-2).

[0186] In step S1911, the first UE (1910-1) transmits a reference signal for paging, i.e., a paging reference signal (PRES). That is, the first UE (1910-1) may transmit the PRES in response to the RAR message. In step S1913, the second UE (1910-2) transmits MSG3. That is, the second UE (1910-2) may transmit MSG3 in response to the RAR message. In step S1915, the base station (1920) transmits MSG4 to the second UE (1910-2). The base station (1920) decodes MSG3 transmitted by the second UE (1910-2) and transmits a message for contention resolution of the second UE (1910-2). In step S1917, the base station (1920) transmits MSG4 to the first UE (1910-1). The base station (1920) detects the PRES transmitted by the first UE (1910-1) and transmits a message for contention resolution of the first UE (1910-1).

[0187] A paging-based RACH procedure may be performed according to any one of the procedures described with reference to FIGS. 19A and 19B . The present disclosure below describes each step of the aforementioned RACH procedure in more detail.

[0188] 1) Action to receive paging messages

[0189] In order to control a terminal receiving a paging to have a higher priority than other terminals triggering the RACH, the following operations may be performed. First, the base station attempts to detect a RACH preamble in an SFN (e.g., SFN-1 transmitting the paging) and assigns one of the undetected preamble indices to the paged terminal. At this time, if there are three UE IDs included in the paging message, that is, if three terminals are paged, the base station sets three different preamble indices. If the number of undetected preamble indices is insufficient, the base station may set the preamble index received with the lowest received power. That is, the base station may compensate for the lack of preamble indices by using at least one preamble index selected in ascending order of received power among the detected preamble indices.

[0190] Additionally, to allow a RACH preamble to be transmitted at a higher power to give a higher priority to a paged terminal, a power-related parameter (e.g., preambleReceivedTargetPower) may be added to the paging message. preambleReceivedTargetPower is set to allow a RACH preamble to be received at a higher power than the reception power of a RACH preamble detected within the paging intervals. If a RACH preamble is received at maximum power (max power), preambleReceivedTargetPower may be set to MPR. In summary, a paging message according to various embodiments may include a preamble index and a power-related parameter (e.g., PreambleReceivedTargetPower).

[0191] Paging messages are broadcast, and terminals can measure paging messages on specific beams. Based on the UE ID in the paging message, the terminal can determine whether it belongs to a paging group. If it belongs to a paging group, it transmits a RACH preamble at a RACH opportunity based on its UE ID and the pairing preamble index included in the paging message.

[0192] 2) Transmitting RACH preamble

[0193] A terminal transmits a RACH preamble at a RACH opportunity. At this time, the preamble index is not randomly selected, but a dedicated preamble index indicated by a paging message is used. The reason for using a dedicated preamble index is to reduce the probability of competition between paged terminals. In addition, if another terminal that is not paged (hereinafter referred to as a "general terminal" or "other terminal") uses the same preamble index as the paged terminal, the TA (timing advance) included in the RAR may be set based on the RACH preamble of the other terminal, not the RACH preamble transmitted by the paged terminal.

[0194] In addition, it is necessary to determine which beam the paged terminal is aligned to. Here, the beam refers to the downlink transmission beam of the base station, and being aligned to the beam means that the terminal is located in the coverage of the corresponding downlink transmission beam, or in other words, that the corresponding downlink transmission beam is directed toward the terminal. First, which beam the terminal is aligned to can be identified using the preamble index assigned to the paged terminal. Since the RACH opportunity is set to be associated with the downlink transmission beam, it can be confirmed which downlink transmission beam the terminal that transmitted the RACH preamble received based on which RACH opportunity the RACH preamble of the assigned preamble index was detected. Therefore, the base station can determine which beam the paged terminal is aligned to based on the RACH opportunity in which the preamble index assigned to the paged terminal is detected.

[0195] However, a general terminal can also select the same preamble index. Therefore, in addition to the preamble index, the base station can measure the received power of the RACH preamble and identify the beam based on the measured power. Through the target power indicated by the paging message, the base station can expect that the RACH preamble transmitted by the paged terminal will have a higher received power than the RACH preamble transmitted by other terminals. Therefore, the base station can determine the downlink transmission beam toward the paged terminal primarily using the preamble index and additionally using the received power. That is, the base station can determine that the paged terminal is within the coverage of the downlink transmission beam associated with the RACH opportunity in which the RACH preamble received with the target power is detected.

[0196] According to various embodiments, the transmission power of the proposed PRACH preamble may be determined as "RACH power = preambleReceivedTargetPower + DELTA_PREAMBLE + (PREAMBLE_POWER_RAMPING_COUNTER - 1) Х PREAMBLE_POWER_RAMPING_STEP + POWER_OFFSET_2STEP_RA + Paging_RA". preambleReceivedTargetPower is indicated via a paging message, and Paging_RA is an offset value for power increase for retransmission, which is a parameter for increasing the step size of ramp-up so that the PRACH preamble can reach the maximum power faster than other terminals transmitting the RACH preamble when the power of the PRACH preamble is at the maximum value. Paging_RA may be set and / or indicated to the terminal via RRC signaling, system information (e.g., SIB), or paging message.

[0197] As described above, the base station can determine that a paged terminal exists within the area of ​​a specific downlink transmission beam through the detected preamble index. However, since other terminals transmitting RACH preambles may also use the same preamble index, determination based solely on the detection result of the preamble index may be erroneous. Therefore, it is possible to additionally identify the signal of the paged terminal using the received power. The technical basis for distinguishing between a paged terminal and a general terminal using the received power of the RACH preamble is as follows.

[0198] Considering terminals with the same preamble index, the target reception power can be identified through the amplitude from the result of the time domain cross correlation operation. For example, if the target reception power of a RACH preamble for paging is 0 dBm, Ramp-up=3 dBm, and the target reception power of other RACH preambles is -20 dBm, Ramp-up=2 dBm, then considering fading according to the terminal speed, the expected reception power of the RACH preamble for paging is 0 to 3 dBm, and the expected reception power of a general RACH preamble is -20 to -17 dBm. At this time, since power fluctuations may occur depending on the environment, an offset in the expected power may be applied depending on the performance of the receiver. However, in some cases, a general RACH preamble may be received within the range of the expected reception power of a RACH preamble for paging. In this case, terminals can be distinguished using the PRES described below.

[0199]

[0200] In [Equation 2], is the received signal, is the number of receiving antennas, is the index of the terminal that transmitted the signal, is the number of other terminals that are interferers, is the signal of terminal #u received through the nth receiving antenna at time t, means the signal of terminal #m received through the nth receiving antenna at time t.

[0201] PRACH includes a known sequence based on the Zadoff-Chu sequence. When different sequences, i.e., RACH preambles with different preamble indices, are received in the same RACH opportunity, the received powers can be separated through time-domain cross-correlation using multiple correlators. However, if identical sequences are received in the same RACH opportunity, the correlation result will be similar to power boosting. However, because the sequences are not perfectly orthogonal, errors may occur in the power values ​​estimated by each correlation operation. Therefore, distinguishing between RACH preambles for paging and general RACH based on received power cannot completely eliminate the possibility of judgment errors. Therefore, a threshold-based method may be applied rather than distinguishing based on the sensing level of received power. Specifically, the base station can determine that the terminal to be paged is present in the beam if the power of the received signal exceeds a threshold, and can determine that the terminal to be paged is not present in the beam if the power of the received signal is lower than the threshold.

[0202] According to various embodiments of the present disclosure, the following aspects need to be considered in determining a TA. According to the embodiments described above, a RACH preamble transmitted by a paged terminal is more likely to be received at a higher power than a normal RACH preamble. Therefore, when determining a TA, the base station can determine the TA based on a correlation peak value close to the target power of a normal terminal. If the TA is determined based on the paged terminal, if the signal of the other terminal does not exceed the CP (cyclic prefix) boundary, the paged terminal and the other terminal can enter an RRC connection state without contention. On the other hand, if the signal of the other terminal exceeds the CP boundary, the other terminal will perform a backoff operation for contention.

[0203] When TA is determined based on a general terminal, it is possible to consider a case where the signal of the paged terminal exceeds the CP boundary. However, since the paged terminal transmits a signal similar to a synchronization signal (e.g., PSS), even a signal exceeding the CP boundary can be received by the base station, and a round trip delay may be observed. Using this value, TA information can be included in the MSG4 transmitted subsequently, allowing the paged terminal to determine accurate uplink timing.

[0204] According to various embodiments of the present disclosure, the following aspects need to be considered in relation to beam determination. If a paged terminal exists but the base station determines that there is no paged terminal, the base station can transmit information necessary to perform a general 4-step RACH using the beam. In this case, the paged terminal can operate according to the conventional 4-step RACH procedure. According to the proposed technology, it is expected that the TA will be determined based on the RACH preamble transmitted by the paged terminal. In addition, according to the proposed technology, since the paging-only 3-step RACH operation is performed only for the terminal that transmitted the RACH preamble in response to the paging of the base station, it is expected that the paged terminal will receive the RAR first. When RACH preambles having preamble indices assigned to the terminal being paged are received in different RACH opportunities, the base station may transmit RAR / DCI including PRES (paging reference signal) scheduling information using a beam corresponding to a larger reception power among downlink transmission beams associated with the RACH opportunities.

[0205] 3) Action to send RAR

[0206] Using the downlink transmission beam where the paged terminal is expected to be located, resource scheduling information for RAR as well as allocation information for uplink resources for transmitting PRES can be transmitted via the PDCCH. At this time, a dedicated DCI for scheduling PRES (hereinafter referred to as "paging DCI") can be used.

[0207] When using paging DCI, scrambling may be performed on the PDCCH using a value (e.g., temporary mobile subscriber identity (TMSI)) received via a paging message. Accordingly, the terminal may decode the DCI including scheduling information for RAR using the value included in the paging message. In another embodiment, scrambling information (e.g., a scramble index) of the DCI may be indicated via the paging message, or the scrambling information may be predefined. Since different RACH preamble indices are assigned to the paged terminals, even if multiple paged terminals transmit RACH preambles in RACH opportunity(s) associated with a single beam, the base station can distinguish the RACH preambles. Since RARs are transmitted for each RACH preamble index in a typical RACH procedure, the proposed technique may require additional PDCCH resources twice the number of detected RACH preambles. Since each DCI will allocate different resources, paged UEs can use orthogonal PRES resources.

[0208] For efficient use of resources, 1 / N number of paging DCI(s) of the number of paged terminals can be transmitted on each beam. In this case, N terminals can transmit PRES on the same resource. Here, N can be the number of simultaneously transmitting terminals that can guarantee performance in a low SNR environment. In this case, the PDCCH resources that can be saved are {(number of detected RACH preamble indices × 2) / N}. If the channel of the terminals being paged by the base station is a high SNR environment, more PRESs can be transmitted in an overlapping manner, and whether the environment is a high SNR environment can be determined based on the received power of the RACH preambles. When grouping terminals, the base station determines the TA value of each terminal using the received RACH preamble, and thus can group terminals within the CP boundary.

[0209] Regarding the grouping described above, N terminals can be included in one group. Here, N should be selected within a range that can guarantee performance. Here, guaranteeing performance means the following. If there are multiple paged terminals in the same beam, each terminal can transmit a PRES using the same resource. At this time, the number of MSG3s that can be overlapped and transmitted using a single resource through DCI on the PDCCH can be limited to N. This is because if the base station receives MSG3s in the same resource and at the same time, an incorrect index may be detected or a TA with a large error may be set due to receiving too many M-sequences. If there are many paged terminals in a single beam, the base station groups the terminals into N groups and allocates orthogonal resources, such as different symbols and / or frequencies, between different groups. For example, N can be 3.

[0210] The RAR transmitted to the paged terminal may include a CRC and a random access preamble identity (RAPID) (e.g., RACH PreambleIndex). If decoding of the RAR fails, the terminal does not transmit a PRES, performs a backoff, and then retransmits the RACH preamble. Decoding the RAPID allows the base station to restrict participation in contention to only certain terminals. If the CRC check for the RAR is successful, the terminal transmits a PRES and expects to perform additional operations to receive data from the base station.

[0211] 4) Action to transmit PRES

[0212] The PRES is based on an M-sequence, consists of BPSK modulation symbols, and can have a length of 127. The M-sequence can be generated based on the preamble index value within the paging set by the base station. This is because, when multiple paged terminals are located within the same beam, resources can be saved by using the same resources. In addition, when the base station receives a PRES within the same resources, the base station can perform hard decision-based decoding based on information related to the paging message and the RACH preamble.

[0213] If the base station determines that there are three or fewer PRES(es) transmitted by terminal(s) paged on a particular beam based on the received RACH preamble(s), the base station can additionally estimate the uplink timing by performing time domain cross-correlation. If measurement is possible, the base station can attempt an uplink TA using MSG4.

[0214] Figure 20 illustrates an example of detection results for reference signals transmitted by three terminals according to an embodiment of the present disclosure. Figure 20 shows the results for the probability that a base station receives PRESs and accurately predicts sequence IDs and TAs when three terminals transmit PRESs using a DFT-S-OFDM waveform. The channel environment is assumed to be LoS, with only AWGN added. Referring to Figure 23, it is confirmed that the measurement is performed well in the approximately 2 dB SNR range.

[0215] Figures 21a and 21b illustrate examples of detection results of reference signals transmitted by five terminals according to an embodiment of the present disclosure. Figures 21a and 21b illustrate detection probabilities when five terminals transmit PRES. In Figures 21a and 21b, the simulation set the cyclic shift value of the M-sequence to 1 / 127 of the number of terminals. If the time delay is greater than the cyclic shift, performance may deteriorate significantly. Therefore, when the base station groups terminals with different preamble index values ​​after receiving the RACH preamble, the time delay difference can be limited to within the cyclic shift. The simulation set the cyclic shift to 25 and the delay per PRES as shown in Figure 21a, and then observed the detection probability. A detection probability of over 90% was confirmed at approximately 7.5 dB, which may vary depending on the reception delay. If, as in Fig. 21b, there is little time delay, the detection probability can be further improved.

[0216] If the base station misdetects the index of the PRES, the following situation may occur. For example, if the base station receives the RACH preamble and determines that terminal #1, terminal #3, and terminal #5 are terminals to be paged in the corresponding beam, the terminals to be actually paged may be terminal #1 and terminal #3, and terminal #5 may be a general terminal. If terminal #1 and terminal #3 transmit the PRES, and the terminal indices determined by the base station through correlation operation due to noise and time domain delay are index #1 and index #4, the determination for index #4 is a misdetection. However, based on the detection result, the base station transmits MSG4 for index #1 and index #4. MSG4 includes the UE IDs of terminal #1 and terminal #4 to be paged, and terminal #1 can perform subsequent operations. However, terminal #3 does not receive MSG4 and therefore retransmits the RACH preamble. Since terminal #4 is not located in the corresponding beam, the base station will transmit PDCCH and MSG4, but will not receive subsequent messages. This can result in unnecessary resource consumption from the base station's perspective.

[0217] 5) Action to send MSG3

[0218] A terminal performing a typical 4-step RACH procedure can transmit MSG3 using the information contained in the RAR. Since MSG3 is mapped to resources orthogonal to ACK / NACK, it may no longer compete with the paged terminal. However, competition with other terminals may still exist. Furthermore, since the TA is likely to be set based on the paged terminal, this may result in contention.

[0219] 6) Action to send MSG4

[0220] The base station transmits a complete message to the terminal, notifying that the final RRC establishment procedure is complete. This completes the contention resolution operation, and the operation for transmitting downlink data is then performed. If the base station decodes an incorrect index value in the PRES, the base station includes the decoded index value in MSG4. The paged terminal receives MSG4, and if the value is identical to the index value it transmitted, the procedure is initiated. On the other hand, if the index value included in MSG4 is not identical to the index value it transmitted, the terminal attempts to retransmit the RACH preamble after backoff.

[0221] Figure 22 illustrates examples of messages and signals transmitted in a RACH procedure according to one embodiment of the present disclosure. Figure 22 illustrates messages and signals transmitted and / or received in a RACH procedure according to the proposed technology when a paged terminal and a normal terminal exist. In a RACH procedure, if multiple terminals transmit MSG3s through the same resource, contention occurs. The base station selects MSG3 of one of the terminals and transmits it to MSG4. A terminal not indicated by MSG4 is determined to have failed the contention and retransmits the RACH preamble. According to various embodiments of the present disclosure, the resources used by the normal terminal and the paged terminal are orthogonal. Therefore, the probability of contention occurring can be reduced by the number of paged terminals. For example, if 20 terminals (e.g., 18 normal terminals and 2 paged terminals) transmit RACH preambles, the probability of contention is 20 / 64 for all terminals, and if 4 terminals (e.g., 1 paged terminal and 3 normal terminals) transmit the same preamble index and RACH opportunity when transmitting MSG3, the MSG3s are transmitted on the same symbol and frequency resources, and the probability of contention is 3 / 4. By applying the proposed method, paged terminals will not experience contention, and normal terminals can experience contention with a probability reduced by 1 / 2.

[0222] Below, examples of wireless device utilization to which various embodiments of the present disclosure are applied are described.

[0223] Figure 23 illustrates an example of a wireless device applicable to the present disclosure. The wireless device may be implemented in various forms depending on the use case / service (see Figure 1).

[0224] Referring to FIG. 23, the wireless device (200) corresponds to the wireless device (200) of FIG. 2 and may be composed of various elements, components, units / units, and / or modules. For example, the wireless device (200) may include a communication unit (210), a control unit (220), a memory unit (230), and additional elements (240). The communication unit may include a communication circuit (212) and a transceiver(s) (214). For example, the communication circuit (212) may include at least one processor (202) and / or at least one memory (204) of FIG. 2. For example, the transceiver(s) (214) may include at least one transceiver (206) and / or at least one antenna (208) of FIG. 2. The control unit (220) is electrically connected to the communication unit (210), the memory unit (230), and the additional elements (240) and controls the overall operations of the wireless device. For example, the control unit (220) can control the electrical / mechanical operations of the wireless device based on the program / code / command / information stored in the memory unit (230). In addition, the control unit (220) can transmit information stored in the memory unit (230) to an external device (e.g., another communication device) via a wireless / wired interface through the communication unit (210), or store information received from an external device (e.g., another communication device) via a wireless / wired interface in the memory unit (230).

[0225] The additional element (240) may be configured in various ways depending on the type of the wireless device. For example, the additional element (240) may include at least one of a power unit / battery, an input / output unit (I / O unit), a driving unit, and a computing unit. Although not limited thereto, the wireless device may be implemented in the form of a robot (Fig. 1, 100a), a vehicle (Fig. 1, 100b-1, 100b-2), an XR device (Fig. 1, 100c), a portable device (Fig. 1, 100d), a home appliance (Fig. 1, 100e), an IoT device (Fig. 1, 100f), a digital broadcasting terminal, a hologram device, a public safety device, an MTC device, a medical device, a fintech device (or a financial device), a security device, a climate / environmental device, an AI server / device (Fig. 1, 400), a base station (Fig. 1, 200), a network node, etc. Wireless devices may be mobile or stationary depending on the use / service.

[0226] In FIG. 23, various elements, components, units / parts, and / or modules within the wireless device (200) may be entirely interconnected via a wired interface, or at least some may be wirelessly connected via a communication unit (210). For example, within the wireless device (200), the control unit (220) and the communication unit (210) may be wired, and the control unit (220) and a first unit (e.g., 230, 240) may be wirelessly connected via the communication unit (210). In addition, each element, component, unit / part, and / or module within the wireless device (200) may further include at least one element. For example, the control unit (220) may be composed of at least one processor set. For example, the control unit (220) may be composed of a communication control processor, an application processor, an electronic control unit (ECU), a graphics processing processor, a memory control processor, etc. As another example, the memory unit (130) may be composed of RAM (Random Access Memory), DRAM (Dynamic RAM), ROM (Read Only Memory), flash memory, volatile memory, non-volatile memory, and / or a combination thereof.

[0227] Below, the implementation example of Fig. 23 is described in more detail with reference to the drawings.

[0228] Figure 24 illustrates examples of portable devices applicable to the present disclosure. Portable devices may include smartphones, smart pads, wearable devices (e.g., smartwatches, smartglasses), and portable computers (e.g., laptops, etc.). Portable devices may also be referred to as mobile stations (MS), user terminals (UT), mobile subscriber stations (MSS), subscriber stations (SS), advanced mobile stations (AMS), or wireless terminals (WT).

[0229] Referring to FIG. 24, the portable device (200) may include an antenna unit (208), a communication unit (210), a control unit (220), a memory unit (230), a power supply unit (240a), an interface unit (240b), and an input / output unit (240c). The antenna unit (208) may be configured as a part of the communication unit (210). Blocks 210 to 230 / 240a to 240c of FIG. 24 correspond to blocks 210 to 230 / 240 of FIG. 23, respectively.

[0230] The communication unit (210) can transmit and receive signals (e.g., data, control signals, etc.) with other wireless devices and base stations. The control unit (220) can control components of the mobile device (200) to perform various operations. The control unit (220) can include an AP (Application Processor). The memory unit (230) can store data / parameters / programs / codes / commands required for operating the mobile device (200). In addition, the memory unit (230) can store input / output data / information, etc. The power supply unit (240a) supplies power to the mobile device (200) and can include a wired / wireless charging circuit, a battery, etc. The interface unit (240b) can support connection between the mobile device (200) and other external devices. The interface unit (240b) can include various ports (e.g., audio input / output ports, video input / output ports) for connection with external devices. The input / output unit (240c) can input or output video information / signals, audio information / signals, data, and / or information input from a user. The input / output unit (240c) may include a camera, a microphone, a user input unit, a display unit (240d), a speaker, and / or a haptic module.

[0231] For example, in the case of data communication, the input / output unit (240c) obtains information / signals (e.g., touch, text, voice, image, video) input by the user, and the obtained information / signals can be stored in the memory unit (230). The communication unit (210) converts the information / signals stored in the memory into wireless signals, and can directly transmit the converted wireless signals to other wireless devices or to a base station. In addition, the communication unit (210) can receive wireless signals from other wireless devices or base stations, and then restore the received wireless signals to the original information / signals. The restored information / signals can be stored in the memory unit (230) and then output in various forms (e.g., text, voice, image, video, haptic) through the input / output unit (240c).

[0232] Figure 25 illustrates examples of vehicles or autonomous vehicles applicable to the present disclosure. The vehicles or autonomous vehicles may be implemented as mobile robots, cars, trains, manned / unmanned aerial vehicles (AVs), ships, etc.

[0233] Referring to FIG. 25, a vehicle or autonomous vehicle (200-1) may include an antenna unit (208-1), a communication unit (210-1), a control unit (220-1), a driving unit (240a-1), a power supply unit (240b-1), a sensor unit (240c-1), and an autonomous driving unit (240d-1). The antenna unit (208-1) may be configured as a part of the communication unit (210-1). Blocks 210-1 / 230-1 / 240a-1 to 240d-1 of FIG. 25 correspond to blocks 210 / 230 / 240 of FIG. 23, respectively.

[0234] The communication unit (210-1) can transmit and receive signals (e.g., data, control signals, etc.) with external devices such as other vehicles, base stations (e.g., base stations, roadside base stations (ROS), etc.), and servers. The control unit (220-1) can control elements of the vehicle or autonomous vehicle (200-1) to perform various operations. The control unit (220-1) may include an ECU (Electronic Control Unit). The drive unit (240a-1) can drive the vehicle or autonomous vehicle (200-1) on the ground. The drive unit (240a-1) may include an engine, a motor, a power train, wheels, brakes, a steering device, etc. The power supply unit (240b-1) supplies power to the vehicle or autonomous vehicle (200-1) and may include a wired / wireless charging circuit, a battery, etc. The sensor unit (240c-1) can obtain vehicle status, surrounding environment information, user information, etc. The sensor unit (240c-1) may include an IMU (inertial measurement unit) sensor, a collision sensor, a wheel sensor, a speed sensor, an incline sensor, a weight detection sensor, a heading sensor, a position module, a vehicle forward / backward sensor, a battery sensor, a fuel sensor, a tire sensor, a steering sensor, a temperature sensor, a humidity sensor, an ultrasonic sensor, an illuminance sensor, a pedal position sensor, etc. The autonomous driving unit (240d-1) may implement a technology for maintaining a driving lane, a technology for automatically controlling speed such as adaptive cruise control, a technology for automatically driving along a set path, a technology for automatically setting a path and driving when a destination is set, etc.

[0235] For example, the communication unit (210-1) can receive map data, traffic information data, etc. from an external server. The autonomous driving unit (240d-1) can generate an autonomous driving route and driving plan based on the acquired data. The control unit (220-1) can control the drive unit (240a-1) so that the vehicle or autonomous vehicle (200-1) moves along the autonomous driving route according to the driving plan (e.g., speed / direction control). During autonomous driving, the communication unit (210-1) can irregularly / periodically acquire the latest traffic information data from an external server and can acquire surrounding traffic information data from surrounding vehicles. In addition, during autonomous driving, the sensor unit (240c-1) can acquire vehicle status and surrounding environment information. The autonomous driving unit (240d-1) can update the autonomous driving route and driving plan based on newly acquired data / information. The communication unit (210-1) can transmit information regarding the vehicle location, autonomous driving route, driving plan, etc. to an external server. The external server can predict traffic information data in advance using AI technology, etc. based on information collected from the vehicle or autonomous vehicles, and provide the predicted traffic information data to the vehicle or autonomous vehicles. If the device (220-2) is an autonomous vehicle, it can perform the same procedure as the vehicle or autonomous vehicle (200-1). In addition, if the device (220-2) is a base station or a roadside base station, the device (220-2) can transmit data, control signals, etc. to the vehicle or autonomous vehicle (200-1) through the communication unit (210-2).

[0236] Figure 26 illustrates an example of a vehicle applicable to the present disclosure. The vehicle may also be implemented as a means of transportation, a train, an aircraft, a ship, etc. Referring to Figure 26, the vehicle (200) may include a communication unit (210), a control unit (220), a memory unit (230), an input / output unit (240a), and a position measurement unit (240b). Here, blocks 210 to 230 / 240a to 240b correspond to blocks 210 to 230 / 240 of Figure 23, respectively.

[0237] The communication unit (210) can transmit and receive signals (e.g., data, control signals, etc.) with other vehicles or external devices such as base stations. The control unit (220) can control components of the vehicle (200) to perform various operations. The memory unit (230) can store data / parameters / programs / codes / commands that support various functions of the vehicle (100). The input / output unit (240a) can output AR / VR objects based on information in the memory unit (230). The input / output unit (240a) can include a HUD. The position measurement unit (240b) can obtain position information of the vehicle (200). The position information can include absolute position information of the vehicle (200), position information within a driving line, acceleration information, position information with respect to surrounding vehicles, etc. The position measurement unit (240b) can include GPS and various sensors.

[0238] For example, the communication unit (210) of the vehicle (200) can receive map information, traffic information, etc. from an external server and store them in the memory unit (230). The location measurement unit (240b) can obtain vehicle location information through GPS and various sensors and store the information in the memory unit (230). The control unit (220) can create a virtual object based on the map information, traffic information, and vehicle location information, and the input / output unit (240a) can display the created virtual object on the vehicle window (240a-1, 240a-2). In addition, the control unit (220) can determine whether the vehicle (200) is being driven normally within the driving line based on the vehicle location information. If the vehicle (200) abnormally deviates from the driving line, the control unit (220) can display a warning on the vehicle window through the input / output unit (240a). Additionally, the control unit (220) can broadcast a warning message regarding driving abnormalities to surrounding vehicles through the communication unit (210). Depending on the situation, the control unit (220) can transmit vehicle location information and information regarding driving / vehicle abnormalities to relevant authorities through the communication unit (210).

[0239] Figure 27 illustrates examples of XR devices applicable to the present disclosure. The XR devices may be implemented as HMDs, head-up displays (HUDs) installed in vehicles, televisions, smartphones, computers, wearable devices, home appliances, digital signage, vehicles, robots, and the like.

[0240] Referring to FIG. 27, the XR device (200a) may include a communication unit (210), a control unit (220), a memory unit (230), an input / output unit (240a), a sensor unit (240b), and a power supply unit (240c). Here, blocks 210 to 230 / 240a to 240c of FIG. 27 correspond to blocks 210 to 230 / 240 of FIG. 23, respectively.

[0241] The communication unit (210) can transmit and receive signals (e.g., media data, control signals, etc.) with external devices such as other wireless devices, portable devices, or media servers. The media data can include videos, images, sounds, etc. The control unit (220) can control components of the XR device (200a) to perform various operations. For example, the control unit (220) can be configured to control and / or perform procedures such as video / image acquisition, (video / image) encoding, metadata generation and processing, etc. The memory unit (230) can store data / parameters / programs / codes / commands required for driving the XR device (200a) / generating XR objects. The input / output unit (240a) can obtain control information, data, etc. from the outside, and output the generated XR object. The input / output unit (240a) can include a camera, a microphone, a user input unit, a display unit, a speaker, and / or a haptic module. The sensor unit (240b) can obtain the XR device status, surrounding environment information, user information, etc. The sensor unit (240b) may include a proximity sensor, an illuminance sensor, an acceleration sensor, a magnetic sensor, a gyro sensor, an inertial sensor, an RGB sensor, an IR sensor, a fingerprint recognition sensor, an ultrasonic sensor, a light sensor, a microphone, and / or a radar. The power supply unit (240c) supplies power to the XR device (200a) and may include a wired / wireless charging circuit, a battery, etc.

[0242] For example, the memory unit (230) of the XR device (200a) may include information (e.g., data, etc.) required for creating an XR object (e.g., AR / VR / MR object). The input / output unit (240a) may obtain a command to operate the XR device (200a) from the user, and the control unit (220) may operate the XR device (200a) according to the user's operating command. For example, when the user attempts to watch a movie, news, etc. through the XR device (200a), the control unit (220) may transmit content request information to another device (e.g., a mobile device (200b)) or a media server through the communication unit (230). The communication unit (230) may download / stream content such as movies and news from another device (e.g., a mobile device (200b)) or a media server to the memory unit (230). The control unit (220) controls and / or performs procedures such as video / image acquisition, (video / image) encoding, and metadata generation / processing for content, and can generate / output an XR object based on information about surrounding space or real objects acquired through the input / output unit (240a) / sensor unit (240b).

[0243] In addition, the XR device (200a) is wirelessly connected to the mobile device (200b) through the communication unit (210), and the operation of the XR device (200a) can be controlled by the mobile device (200b). For example, the mobile device (200b) can act as a controller for the XR device (200a). To this end, the XR device (200a) can obtain 3D location information of the mobile device (200b), and then generate and output an XR object corresponding to the mobile device (200b).

[0244] Figure 28 illustrates examples of robots applicable to the present disclosure. Robots can be classified into industrial, medical, household, and military types, depending on their intended use or field.

[0245] Referring to FIG. 28, the robot (200) may include a communication unit (210), a control unit (220), a memory unit (230), an input / output unit (240a), a sensor unit (240b), and a driving unit (240c). Here, blocks 210 to 230 / 240a to 240c of FIG. 28 correspond to blocks 210 to 230 / 240 of FIG. 23, respectively.

[0246] The communication unit (210) can transmit and receive signals (e.g., driving information, control signals, etc.) with external devices such as other wireless devices, other robots, or control servers. The control unit (220) can control components of the robot (200) to perform various operations. The memory unit (230) can store data / parameters / programs / codes / commands that support various functions of the robot (200). The input / output unit (240a) can obtain information from the outside of the robot (200) and output information to the outside of the robot (200). The input / output unit (240a) can include a camera, a microphone, a user input unit, a display unit, a speaker, and / or a haptic module. The sensor unit (240b) can obtain internal information of the robot (200), surrounding environment information, user information, etc. The sensor unit (240b) may include a proximity sensor, an illuminance sensor, an acceleration sensor, a magnetic sensor, a gyro sensor, an inertial sensor, an IR sensor, a fingerprint recognition sensor, an ultrasonic sensor, a light sensor, a microphone, a radar, etc. The driving unit (240c) may perform various physical operations, such as moving the robot joints. In addition, the driving unit (240c) may enable the robot (200) to drive on the ground or fly in the air. The driving unit (240c) may include an actuator, a motor, wheels, brakes, propellers, etc.

[0247] Figure 29 illustrates an example of an AI device applicable to the present disclosure.

[0248] AI devices can be implemented as fixed or mobile devices, such as TVs, projectors, smartphones, PCs, laptops, digital broadcasting terminals, tablet PCs, wearable devices, set-top boxes (STBs), radios, washing machines, refrigerators, digital signage, robots, and vehicles.

[0249] Referring to FIG. 29, the AI ​​device (200) may include a communication unit (210), a control unit (220), a memory unit (230), an input / output unit (240a / 240b), a learning processor unit (240c), and a sensor unit (240d). Blocks 210 to 230 / 240a to 240d of FIG. 29 correspond to blocks 210 to 230 / 140 of FIG. 23, respectively.

[0250] The communication unit (210) can transmit and receive wired and wireless signals (e.g., sensor information, user input, learning models, control signals, etc.) to and from external devices such as other AI devices (e.g., 100a to 100f, 120 of FIG. 1) or AI servers (e.g., 100g of FIG. 1) using wired and wireless communication technology. To this end, the communication unit (210) can transmit information within the memory unit (230) to the external device or transfer a signal received from the external device to the memory unit (230).

[0251] The control unit (220) may determine at least one executable operation of the AI ​​device (200) based on information determined or generated using a data analysis algorithm or a machine learning algorithm. In addition, the control unit (220) may control components of the AI ​​device (200) to perform the determined operation. For example, the control unit (220) may request, search, receive, or utilize data from the learning processor unit (240c) or the memory unit (230), and may control components of the AI ​​device (200) to perform at least one executable operation, a predicted operation, or an operation determined to be desirable. In addition, the control unit (220) may collect history information including the operation contents of the AI ​​device (200) or user feedback on the operation, and store the collected history information in the memory unit (230) or the learning processor unit (240c), or transmit the collected history information to an external device such as an AI server (FIG. 1, 100g). The collected history information may be used to update a learning model.

[0252] The memory unit (230) can store data that supports various functions of the AI ​​device (200). For example, the memory unit (230) can store data obtained from the input unit (240a), data obtained from the communication unit (210), output data of the learning processor unit (240c), and data obtained from the sensing unit (140). In addition, the memory unit (230) can store control information and / or software codes necessary for the operation / execution of the control unit (220).

[0253] The input unit (240a) can obtain various types of data from the outside of the AI ​​device (200). For example, the input unit (220) can obtain learning data for model learning, input data to which the learning model will be applied, etc. The input unit (240a) may include a camera, a microphone, and / or a user input unit. The output unit (240b) may generate output related to vision, hearing, or touch. The output unit (240b) may include a display unit, a speaker, and / or a haptic module, etc. The sensing unit (140d) can obtain at least one of internal information of the AI ​​device (200), information about the surrounding environment of the AI ​​device (200), and user information using various sensors. The sensing unit (140d) may include a proximity sensor, an illuminance sensor, an acceleration sensor, a magnetic sensor, a gyro sensor, an inertial sensor, an RGB sensor, an IR sensor, a fingerprint recognition sensor, an ultrasonic sensor, a light sensor, a microphone, and / or a radar, etc.

[0254] The learning processor unit (240c) can train a model composed of an artificial neural network using learning data. The learning processor unit (240c) can perform AI processing together with the learning processor unit of the AI ​​server (Fig. 1, 100g). The learning processor unit (240c) can process information received from an external device via the communication unit (210) and / or information stored in the memory unit (230). In addition, the output value of the learning processor unit (240c) can be transmitted to an external device via the communication unit (210) and / or stored in the memory unit (230).

[0255] 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).

[0256] 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.

[0257] 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.

[0258] 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.

[0259] Additionally, embodiments of the present disclosure can be applied to various applications such as autonomous vehicles and drones.

Claims

1. In a method of operation performed by a terminal in a wireless communication system, A step of receiving a paging message from a base station; A step of transmitting a RACH (random access channel) preamble to the base station; A step of receiving a random access response (RAR) message from the base station; a step of transmitting a reference signal to the base station; and A step of receiving a contention resolution message from the base station, A method wherein the paging message includes at least one of information related to a preamble index for the RACH preamble or information related to transmission power of the RACH preamble.

2. In claim 1, A method in which the RACH preamble includes a sequence corresponding to a preamble index indicated by the paging message.

3. In claim 1, A method in which the information related to the above transmission power includes a target reception power value for the RACH preamble at the base station.

4. In claim 3, A method further comprising the step of determining the transmission power of the RACH preamble based on the target reception power value and an offset value for power increase for retransmission.

5. In claim 4, The above offset value is received through system information or the paging message.

6. In claim 1, A method further comprising the step of receiving downlink control information (DCI) including scheduling information for the RAR message and scheduling information for the reference signal.

7. In claim 6, The above DCI is decoded using a value included in the paging message.

8. In claim 1, A method further comprising the step of generating a sequence for the reference signal based on the RACH preamble.

9. In a method of operation performed by a base station in a wireless communication system, A step of transmitting a paging message to a terminal; A step of receiving a RACH (random access channel) preamble from the terminal; A step of transmitting a RAR (random access response) message to the terminal; A step of receiving a reference signal from the terminal; and A step of transmitting a contention resolution message to the terminal, A method wherein the paging message includes at least one of information related to a preamble index for the RACH preamble or information related to transmission power of the RACH preamble.

10. In claim 9, A method further comprising the step of identifying a downlink beam toward the terminal based on at least one of a RACH opportunity in which the preamble index is detected or the reception power of the RACH preamble.

11. In claim 10, The step of sending the above RAR message is: A method comprising the step of transmitting DCI (downlink control information) for scheduling the RAR message and the RAR message using the downlink beam.

12. In a terminal in a communication system, Transmitter and receiver; and A processor connected to the above transmitter and receiver is included, The above processor, Receive a paging message from the base station, Transmit a RACH (random access channel) preamble to the base station, Receive a RAR (random access response) message from the base station, Transmit a reference signal to the above base station, configured to receive a contention resolution message from the above base station, A terminal in which the paging message includes at least one of information related to a preamble index for the RACH preamble or information related to transmission power of the RACH preamble.

13. In a base station in a communication system, Transmitter and receiver; and A processor connected to the above transmitter and receiver is included, The above processor, Send a paging message to the terminal, Receive a RACH (random access channel) preamble from the terminal, Send a RAR (random access response) message to the terminal, Receive a reference signal from the above terminal, It is configured to transmit a contention resolution message to the above terminal, A base station wherein the paging message includes at least one of information related to a preamble index for the RACH preamble or information related to transmission power of the RACH preamble.

14. In communication devices, At least one processor; At least one computer memory connected to said at least one processor and storing instructions that direct operations when executed by said at least one processor, The above actions are, A step of receiving a paging message from a base station; A step of transmitting a RACH (random access channel) preamble to the base station; A step of receiving a random access response (RAR) message from the base station; a step of transmitting a reference signal to the base station; and A step of receiving a contention resolution message from the base station, A communication device wherein the paging message includes at least one of information related to a preamble index for the RACH preamble or information related to transmission power of the RACH preamble.

15. In a non-transitory computer-readable medium storing at least one instruction, comprising at least one instruction executable by the processor, At least one of the above commands causes the device to: Receive a paging message from the base station, Transmit a RACH (random access channel) preamble to the base station, Receive a RAR (random access response) message from the base station, Transmit a reference signal to the above base station, Instructs to receive a contention resolution message from the above base station, A computer-readable medium wherein the paging message includes at least one of information related to a preamble index for the RACH preamble or information related to transmission power of the RACH preamble.

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