Method and device for operating device in wireless communication system

Abstract

Provided are a method for operating a device in a wireless communication system and a device using the method. The device may be a terminal, and the terminal transmits a fast beam access (FBA) request to some of a plurality of transmission and reception points (TRPs), receives an FBA response from the some of the TRPs, and communicates with the plurality of TRPs on the basis of the FBA response, wherein the FBA response includes information on beams between the plurality of TRPs and the terminal, the information being determined on the basis of a location of the terminal.

Description

Method of operation of a device and device in a wireless communication system

[0001] The present disclosure relates to a method of operation of a device in a wireless communication system and a device utilizing said method.

[0002] Wireless communication systems are being widely deployed to provide various types of communication services, such as voice and data. Generally, a wireless communication system is a multiple access system capable of supporting communication with multiple users by sharing available system resources (bandwidth, transmission power, etc.). Examples of multiple access systems include CDMA (Code Division Multiple Access), FDMA (Frequency Division Multiple Access), TDMA (Time Division Multiple Access), SDMA (Space Division Multiple Access), OFDMA (Orthogonal Frequency Division Multiple Access), SC-FDMA (Single Carrier Frequency Division Multiple Access), and IDMA (Interleave Division Multiple Access).

[0003] As more communication devices require larger communication capacities, the need for enhanced mobile broadband communication compared to existing radio access technology (RAT) is emerging. Furthermore, Massive Machine Type Communications (MTC), which connects multiple devices and objects to provide various services anytime and anywhere, is also one of the major issues to be considered in next-generation communication. In addition, communication system designs that take into account services and terminals sensitive to reliability and latency are being discussed. Thus, the introduction of next-generation radio access technologies that consider enhanced mobile broadband communication, massive MTC, and Ultra-Reliable and Low Latency Communication (URLC) is being discussed, and for convenience, this technology is referred to as new RAT or NR in this disclosure.

[0004] Downlink beam management in NR consists of beam acquisition and beam tracking. Beam acquisition can occur during the initial cell search process of the system or immediately after a beam failure. Beam tracking involves measuring and reporting the beam connection between the base station and the terminal after beam acquisition, and managing the beam connection to maximize the wireless quality through beam reconfiguration.

[0005] In NR, a base station can communicate with a terminal using multiple TRPs (transmit receive points). This can be referred to as multi-TRP.

[0006] However, beam acquisition in multiple TRPs of NR is time-consuming. To perform beam acquisition in multiple TRPs using conventional technology, beam acquisition is generally performed for a single TRP, followed by a process of receiving an RRC measurement report and configuration information through RRC reconfiguration. In other words, beam acquisition for multiple TRP beam links is performed based on the terminal's measurements. Since this process involves measurement for multiple TRPs, it is time-consuming.

[0007] The technical problem that the present disclosure aims to solve is to provide a method of operation of a device in a wireless communication system and a device utilizing said method.

[0008] A method of operation of a device in a wireless communication system and a device utilizing said method are provided. According to said method, a terminal connects to a base station through a random access process, and the terminal transmits a fast beam access (FBA) request to some of the transmit receive points (TRPs) connected to the base station, and the terminal receives an FBA response from said TRPs, and communicates with said TRPs based on said FBA response, wherein the FBA response includes information regarding beams between said TRPs and said terminal, which is determined based on the location of said terminal.

[0009] In another aspect, a terminal, device, or computer-readable recording medium is provided for executing the above method.

[0010] In another aspect, a method of operation of a TRP and a TRP utilizing said method are provided. According to said method, some of the TRPs among a plurality of transmit receive points (TRPs) connected to a base station receive a fast beam access (FBA) request from the terminal, and some of the TRPs transmit an FBA response to the terminal, and the plurality of TRPs communicate with the terminal based on the FBA response, wherein the FBA response includes information regarding beams between the plurality of TRPs and the terminal, which is determined based on the location of the terminal.

[0011] Establishing a large number of TRPs and multiple TRP beam links can significantly reduce the probability of beam failure. According to the method of the present disclosure, such multiple TRP links can be quickly captured. In the prior art, establishing multiple TRP beam links requires performing measurements and measurement reports related to each TRP, whereas the method according to the present disclosure can omit these processes, thereby enabling rapid access.

[0012] The effects obtainable from the embodiments of the present disclosure are not limited to those mentioned above, and other unmentioned effects can be clearly derived and understood by a person skilled in the art to which the technical configuration of the present disclosure applies from the description of the embodiments of the present disclosure below. That is, unintended effects resulting from implementing the configuration described in the present disclosure can also be derived by a person skilled in the art from the embodiments of the present disclosure.

[0013] FIG. 1 illustrates a wireless communication system to which the present disclosure may be applied.

[0014] Figure 2 is a block diagram showing the radio protocol architecture for the user plane.

[0015] Figure 3 is a block diagram showing the wireless protocol structure for the control plane.

[0016] Figure 4 illustrates the system structure of a New Generation Radio Access Network (NG-RAN) to which NR is applied.

[0017] Figure 5 illustrates the functional partitioning between NG-RAN and 5GC.

[0018] Figure 6 illustrates a frame structure that can be applied in NR.

[0019] Figure 7 illustrates the slot structure of an NR frame.

[0020] Figure 8 illustrates a core set.

[0021] Figure 9 illustrates an example of a frame structure for a new wireless access technology.

[0022] Figure 10 illustrates the structure of a self-contained slot.

[0023] Figure 11 illustrates physical channels and general signal transmission.

[0024] Figure 12 is an example of a CSI-related procedure.

[0025] FIG. 13 is a flowchart showing an example of downlink transmission and reception operation.

[0026] FIG. 14 is a flowchart showing an example of an uplink transmission and reception operation.

[0027] FIG. 15 illustrates a procedure in which a terminal performs V2X or SL communication depending on the transmission mode.

[0028] Figure 16 shows three types of casts.

[0029] Figure 17 shows general terms related to the functional framework of RAN intelligence.

[0030] Figure 18 shows an application example and performance of a channel path map.

[0031] Figure 19 shows an example of transmitting an SSB beam and a CSI-RS beam in a downlink.

[0032] Figure 20 is a flowchart showing an example of a DL BM procedure using SSB.

[0033] Figure 21 shows an example of a DL BM procedure using CSI-RS.

[0034] Figure 22 illustrates the Rx beam determination process of a terminal.

[0035] Figure 23 is a flowchart showing an example of the transmission beam determination process of a base station.

[0036] FIG. 24 shows an example of resource allocation in the time and frequency domains related to the operation of FIG. 21.

[0037] Figure 25 shows an example of a UL BM procedure using SRS.

[0038] Figure 26 is a flowchart showing an example of a UL BM procedure using SRS.

[0039] Figure 27 illustrates a 4-step RACH procedure.

[0040] Figure 28 illustrates a two-step RACH procedure.

[0041] Figure 29 shows an example of multiple TRPs.

[0042] FIG. 30 illustrates a signaling procedure between a terminal and a base station or TRP (network) in relation to FBA.

[0043] Figure 31 shows an example of performing the FBA procedure during the signaling process of 5G NR.

[0044] Figure 32 illustrates the timeline of the FBA process.

[0045] Figure 33 illustrates a part of the FBA process.

[0046] Figure 34 illustrates terminal operation when there is no PRACH resource allocation for FBA.

[0047] FIG. 35 shows the effect of the method of the present disclosure.

[0048] FIG. 36 illustrates a method of operation of a terminal according to one embodiment of the present disclosure.

[0049] FIG. 37 illustrates a wireless device that can be applied to the present specification.

[0050] Figure 38 illustrates an example of a signal processing module structure.

[0051] Figure 39 illustrates another example of a signal processing module structure within a transmission device.

[0052] FIG. 40 illustrates an example of a wireless communication device according to an embodiment of the present disclosure.

[0053] Figure 41 illustrates another example of a wireless device.

[0054] FIG. 42 illustrates a communication system (1) applicable to the present specification.

[0055] In this specification, “A or B” may mean “only A,” “only B,” or “both A and B.” Alternatively, in this specification, “A or B” may be interpreted as “A and / or B.” For example, in this specification, “A, B or C” may mean “only A,” “only B,” “only C,” or “any combination of A, B and C.”

[0056] As used herein, a slash ( / ) or a comma may mean “and / or.” For example, “A / B” may mean “A and / or B.” Accordingly, “A / B” may mean “only A,” “only B,” or “both A and B.” For example, “A, B, C” may mean “A, B or C.”

[0057] In this specification, “at least one of A and B” may mean “only A,” “only B,” or “both A and B.” Additionally, in this specification, the expressions “at least one of A or B” or “at least one of A and / or B” may be interpreted as synonymous with “at least one of A and B.”

[0058] Additionally, in this specification, “at least one of A, B and C” may mean “only A,” “only B,” “only C,” or “any combination of A, B and C.” Additionally, “at least one of A, B or C” or “at least one of A, B and / or C” may mean “at least one of A, B and C.”

[0059] Additionally, parentheses used in this specification may mean “for example.” Specifically, when indicated as “Control Information (PDCCH),” “PDCCH” may be proposed as an example of “Control Information.” In other words, “Control Information” in this specification is not limited to “PDCCH,” and “PDCCH” may be proposed as an example of “Control Information.” Furthermore, even when indicated as “Control Information (i.e., PDCCH),” “PDCCH” may be proposed as an example of “Control Information.”

[0060] Technical features described individually within a single drawing in this specification may be implemented individually or simultaneously.

[0061] The following drawings are prepared to illustrate a specific example of the present specification. The names of specific devices or specific signals / messages / fields described in the drawings are presented as examples, and therefore the technical features of the present specification are not limited to the specific names used in the following drawings.

[0062] Figure 1 illustrates a wireless communication system. This can also be called an E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network), or an LTE (Long Term Evolution) / LTE-A system.

[0063] E-UTRAN includes a base station (20: Base Station, BS) that provides a control plane and a user plane to a terminal (10: User Equipment, UE). The terminal (10) may be fixed or mobile and may be referred to by other terms such as MS (Mobile station), UT (User Terminal), SS (Subscriber Station), MT (mobile terminal), Wireless Device, or terminal. The base station (20) refers to a fixed station that communicates with the terminal (10) and may be referred to by other terms such as eNB (evolved-NodeB), BTS (Base Transceiver System), or Access Point.

[0064] Base stations (20) can be connected to each other through an X2 interface. The base station (20) is connected to the EPC (Evolved Packet Core, 30) through the S1 interface, more specifically to the MME (Mobility Management Entity) through the S1-MME and to the S-GW (Serving Gateway) through the S1-U.

[0065] The EPC (30) consists of an MME, an S-GW, and a P-GW (Packet Data Network-Gateway). The MME holds information regarding the terminal's connection information or capabilities, and this information is primarily used for managing the terminal's mobility. The S-GW is a gateway with an E-UTRAN as its endpoint, and the P-GW is a gateway with a PDN as its endpoint.

[0066] The layers of the Radio Interface Protocol between a terminal and a network can be classified into L1 (Layer 1), L2 (Layer 2), and L3 (Layer 3) based on the lower three layers of the Open System Interconnection (OSI) model, which is widely known in communication systems. Among these, the physical layer, which belongs to Layer 1, provides information transfer services using a physical channel, while the Radio Resource Control (RRC) layer, located at Layer 3, performs the role of controlling radio resources between the terminal and the network. To this end, the RRC layer exchanges RRC messages between the terminal and the base station.

[0067] FIG. 2 is a block diagram showing the radio protocol architecture for the user plane. FIG. 3 is a block diagram showing the radio protocol architecture for the control plane. The user plane is a protocol stack for transmitting user data, and the control plane is a protocol stack for transmitting control signals.

[0068] Referring to Figures 2 and 3, the physical layer (PHY layer) provides information transfer services to upper layers using a physical channel. The physical layer is connected to the upper layer, the MAC (Medium Access Control) layer, through a transport channel. Data travels between the MAC layer and the physical layer through the transport channel. Transport channels are classified according to how and with what characteristics data is transmitted through a wireless interface.

[0069] Data travels between different physical layers, specifically between the physical layers of the transmitter and the receiver, through a physical channel. This physical channel can be modulated using the Orthogonal Frequency Division Multiplexing (OFDM) method and utilizes time and frequency as wireless resources.

[0070] The functions of the MAC layer include mapping between logical channels and transport channels, and multiplexing / demultiplexing MAC SDUs (service data units) belonging to logical channels into transport blocks provided to physical channels over the transport channel. The MAC layer provides services to the RLC (Radio Link Control) layer through logical channels.

[0071] The functions of the RLC layer include the concatenation, segmentation, and reassembly of RLC SDUs. To ensure the various Quality of Service (QoS) required by Radio Bearers (RBs), the RLC layer provides three operating modes: Transparent Mode (TM), Unacknowledged Mode (UM), and Acknowledged Mode (AM). AM RLC provides error correction through Automatic Repeat Requests (ARQ).

[0072] The RRC (Radio Resource Control) layer is defined only in the control plane. The RRC layer is responsible for controlling logical channels, transmission channels, and physical channels in relation to the configuration, reconfiguration, and release of wireless bearers. RB refers to a logical path provided by the first layer (PHY layer) and the second layer (MAC layer, RLC layer, PDCP layer) for data transmission between a terminal and a network.

[0073] The functions of the PDCP (Packet Data Convergence Protocol) layer in the user plane include the delivery of user data, header compression, and ciphering. The functions of the PDCP (Packet Data Convergence Protocol) layer in the control plane include the delivery of control plane data and encryption / integrity protection.

[0074] The establishment of an RB refers to the process of defining the characteristics of the wireless protocol layer and channel to provide specific services, and setting their respective specific parameters and operating methods. RBs can be further divided into two types: SRBs (Signaling RBs) and DRBs (Data RBs). SRBs are used as a channel for transmitting RRC messages in the control plane, while DRBs are used as a channel for transmitting user data in the user plane.

[0075] When an RRC connection is established between the terminal's RRC layer and the E-UTRAN's RRC layer, the terminal is in an RRC connected state; otherwise, it is in an RRC idle state.

[0076] Downlink transmission channels for transmitting data from a network to a terminal include a Broadcast Channel (BCH) for transmitting system information and a Shared Channel (SCH) for transmitting user traffic or control messages. Traffic or control messages for downlink multicast or broadcast services may be transmitted via the Shared Channel (SCH) or via a separate Multicast Channel (MCH). Meanwhile, uplink transmission channels for transmitting data from a terminal to a network include a Random Access Channel (RACH) for transmitting initial control messages and a Shared Channel (SCH) for transmitting user traffic or control messages.

[0077] Logical channels that are above the transmission channel and map to the transmission channel include BCCH (Broadcast Control Channel), PCCH (Paging Control Channel), CCCH (Common Control Channel), MCCH (Multicast Control Channel), and MTCH (Multicast Traffic Channel).

[0078] A physical channel consists of multiple OFDM symbols in the time domain and multiple subcarriers in the frequency domain. A single subframe consists of multiple OFDM symbols in the time domain. A resource block is a resource allocation unit composed of multiple OFDM symbols and multiple subcarriers. Additionally, each subframe may utilize specific subcarriers of specific OFDM symbols (e.g., the first OFDM symbol) within that subframe for the Physical Downlink Control Channel (PDCCH), i.e., the L1 / L2 control channel. The Transmission Time Interval (TTI) is the unit time for subframe transmission.

[0079] The following describes new radio access technology (new RAT, NR).

[0080] As more communication devices require larger communication capacities, the need for enhanced mobile broadband communication compared to existing radio access technology (RAT) is emerging. Furthermore, Massive Machine Type Communications (MTC), which connects multiple devices and objects to provide various services anytime and anywhere, is also one of the major issues to be considered in next-generation communication. In addition, communication system designs that take into account services and terminals sensitive to reliability and latency are being discussed. Thus, the introduction of next-generation radio access technologies that consider enhanced mobile broadband communication, massive MTC, and Ultra-Reliable and Low Latency Communication (URLC) is being discussed, and for convenience, this technology is referred to as new RAT or NR in this disclosure.

[0081] Figure 4 illustrates the system structure of a New Generation Radio Access Network (NG-RAN) to which NR is applied.

[0082] Referring to FIG. 4, the NG-RAN may include gNBs and / or eNBs that provide user plane and control plane protocol termination to terminals. FIG. 4 illustrates a case where only gNBs are included. The gNBs (eNBs) are connected to each other via Xn interfaces. The gNBs and eNBs are connected to the 5G Core Network (5GC) via NG interfaces. More specifically, they are connected to the access and mobility management function (AMF) via NG-C interfaces and to the user plane function (UPF) via NG-U interfaces.

[0083] In the following, the term base station (BS) may be replaced by terms such as fixed station, Node B, eNB (evolved-NodeB), gNB (Next Generation NodeB), BTS (base transceiver system), Access Point (AP), network (5G network), AI (Artificial Intelligence) system / module, RSU (road side unit), robot, drone (Unmanned Aerial Vehicle, UAV), AR (Augmented Reality) device, VR (Virtual Reality) device, etc.

[0084] The terminal can be fixed or mobile and can be replaced with terms such as UE (User Equipment), MS (Mobile Station), UT (user terminal), MSS (Mobile Subscriber Station), SS (Subscriber Station), AMS (Advanced Mobile Station), WT (Wireless terminal), MTC (Machine-Type Communication) device, M2M (Machine-to-Machine) device, D2D (Device-to-Device) device, vehicle, RSU (road side unit), robot, AI (Artificial Intelligence) module, drone (Unmanned Aerial Vehicle, UAV), AR (Augmented Reality) device, VR (Virtual Reality) device.

[0085] Figure 5 illustrates the functional partitioning between NG-RAN and 5GC.

[0086] Referring to FIG. 5, the gNB can provide functions such as Inter Cell RRM, RB control, Connection Mobility Control, Radio Admission Control, Measurement Configuration & Provision, and Dynamic Resource Allocation. The AMF can provide functions such as NAS security and idle state mobility processing. The UPF can provide functions such as Mobility Anchoring and PDU processing. The SMF (Session Management Function) can provide functions such as terminal IP address allocation and PDU session control.

[0087] Figure 6 illustrates a frame structure that can be applied in NR.

[0088] Referring to FIG. 6, radio frames (hereinafter abbreviated as frames) may be used for uplink and downlink transmission in NR. A frame has a length of 10 ms and can be defined as two 5 ms half-frames (HF). A half-frame can be defined as five 1 ms subframes (SF). A subframe can be divided into one or more slots, and the number of slots within a subframe depends on the subcarrier spacing (SCS). Each slot contains 12 or 14 OFDM(A) symbols according to the cyclic prefix (CP). When a normal CP is used, each slot contains 14 symbols. When an extended CP is used, each slot contains 12 symbols. Here, the symbols may include OFDM symbols (or CP-OFDM symbols) or SC-FDMA symbols (or DFT-s-OFDM symbols).

[0089] Table 1 below shows an example of a subcarrier spacing configuration (also referred to as subcarrier spacing configuration) μ.

[0090] [Table 1]

[0091]

[0092] The following Table 2 shows the number of slots (N) within a frame according to the subcarrier spacing setting μ. frame,μ slot ), number of slots in the subframe (N subframe,μ slot ), number of symbols in the slot (N slot symb Examples include ) etc.

[0093] [Table 2]

[0094]

[0095] Figure 6 illustrates μ=0, 1, 2, and 3.

[0096] Table 2-1 below illustrates how the number of symbols per slot, the number of slots per frame, and the number of slots per subframe vary depending on the SCS when an extended CP is used.

[0097] [Table 2-1]

[0098]

[0099] In an NR system, OFDM(A) numerology (e.g., SCS, CP length, etc.) can be configured differently among multiple cells merged into a single terminal. Accordingly, the (absolute time) interval of a time resource (e.g., SF, slot, or TTI) (collectively referred to as TU (Time Unit) for convenience) composed of the same number of symbols can be configured differently among the merged cells.

[0100] Figure 7 illustrates a slot structure.

[0101] A slot may contain multiple symbols in the time domain. For example, in the case of a normal CP, one slot may contain 14 symbols (or 7 symbols), but in the case of an extended CP, one slot may contain 12 symbols (or 6 symbols). A carrier may contain multiple subcarriers in the frequency domain. A Resource Block (RB) may be defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. A Bandwidth Part (BWP) may be defined as multiple consecutive (P)RBs in the frequency domain and may correspond to a single numerology (e.g., SCS, CP length, etc.). A carrier may contain up to N (e.g., 4 or 5) BWPs. Data communication is performed through the active BWP, and only one BWP may be active for a single terminal. In a resource grid, each element is referred to as a Resource Element (RE), and a single complex symbol can be mapped to it. A mini-slot can consist of, for example, 2, 4, or 7 symbols.

[0102] The PDCCH (physical downlink control channel) can be composed of one or more CCEs (control channel elements) as shown in Table 3 below.

[0103] [Table 3]

[0104]

[0105] That is, the PDCCH can be transmitted through a resource consisting of 1, 2, 4, 8, or 16 CCEs. Here, the CCE consists of 6 REGs (resource element groups), and one REG consists of one resource block in the frequency domain and one OFDM (orthogonal frequency division multiplexing) symbol in the time domain.

[0106] Monitoring means decoding each PDCCH candidate according to the DCI (downlink control information) format. The terminal monitors a set of PDCCH candidates in one or more core sets (CORESET, described below) on the active DL BWP of each active serving cell where PDCCH monitoring is configured, according to the corresponding set of search spaces.

[0107] In NR, a new unit called a control resource set (CORESET) can be introduced. A terminal can receive PDCCH from the core set.

[0108] Figure 8 illustrates a core set.

[0109] Referring to Fig. 8, the core set is N in the frequency domain. CORESET RB It consists of N resource blocks, and in the time domain N CORESET symb ∈ Can be composed of {1, 2, 3} symbols. N CORESET RB , N CORESET symb This can be provided by the base station through an upper layer signal. As illustrated in FIG. 8, the core set may include a plurality of CCEs (or REGs).

[0110] The terminal can attempt to detect PDCCH in units of 1, 2, 4, 8, or 16 CCEs within the core set. One or more CCEs that can attempt to detect PDCCH may be called PDCCH candidates.

[0111] The terminal can be configured with multiple core sets.

[0112] In conventional wireless communication systems (e.g., LTE / LTE-A), the control domain was configured across the entire system band used by the base station. With the exception of some terminals that support only a narrow band (e.g., eMTC / NB-IoT terminals), all terminals had to be able to receive wireless signals across the entire system band of the base station in order to properly receive and decode control information transmitted by the base station.

[0113] On the other hand, NR introduced the aforementioned core set. A core set can be described as a radio resource for control information that a terminal must receive, and in the frequency domain, only a portion of the system band can be used instead of the entire system band. Additionally, in the time domain, only a portion of the symbols within a slot can be used. A base station can allocate a core set to each terminal and transmit control information through the allocated core set. In NR, a terminal can receive control information from a base station even without necessarily receiving the entire system band.

[0114] A core set may include a terminal-specific core set for transmitting terminal-specific control information and a common core set for transmitting control information common to all terminals.

[0115] Meanwhile, in NR, high reliability may be required depending on the application field, and in such situations, the target block error rate (BLER) for downlink control information (DCI) transmitted through a downlink control channel (e.g., physical downlink control channel: PDCCH) can be significantly lower than that of conventional technology. As an example of a method to satisfy such requirements for high reliability, the amount of content included in the DCI can be reduced, and / or the amount of resources used during DCI transmission can be increased. In this case, the resources may include at least one of resources in the time domain, resources in the frequency domain, resources in the code domain, and resources in the space domain.

[0116] The following technologies / features can be applied in NR.

[0117] Self-contained subframe structure

[0118] Figure 9 illustrates an example of a frame structure for a new wireless access technology.

[0119] In NR, for the purpose of minimizing latency, a structure in which the control channel and the data channel are time-division multiplexed (TDM) within a single TTI, as shown in Fig. 9, can be considered as one of the frame structures.

[0120] Figure 9 illustrates an example in which a downlink control area is located at the front of the TTI and an uplink control area is located at the back of the TTI. The area between the downlink control area and the uplink control area may be used for transmitting downlink data (DL data) or for transmitting uplink data (UL data). A characteristic of this structure is that downlink (DL) reception and uplink (UL) transmission proceed sequentially within a single subframe / slot, allowing DL data to be received and UL ACK / NACK (Acknowledgement / Not-acknowledgement) to be transmitted within a single subframe / slot. Consequently, the time required for data retransmission in the event of a data transmission error is reduced, thereby minimizing the latency of the final data delivery.

[0121] As such, in a data and control TDMed subframe structure, a time gap is required for the transition process between the base station and the terminal from transmit mode to receive mode or from receive mode to transmit mode. To this end, in a self-contained subframe structure, some OFDM symbols at the time of transition from DL to UL can be set as a guard period (GP).

[0122] Figure 10 illustrates the structure of a self-contained slot.

[0123] In an NR system, a single slot may contain a DL control channel, DL or UL data, a UL control channel, etc. For example, the first N symbols within the slot may be used to transmit a DL control channel (hereinafter referred to as the DL control area), and the last M symbols within the slot may be used to transmit a UL control channel (hereinafter referred to as the UL control area). N and M are each integers greater than or equal to 0. The resource area (hereinafter referred to as the data area) located between the DL control area and the UL control area may be used for transmitting DL data or for transmitting UL data. As an example, the following configuration may be considered. Each section is listed in chronological order.

[0124] 1. DL only configuration

[0125] 2. UL only configuration

[0126] 3. Mixed UL-DL Configuration

[0127] - DL Area + GP (Guard Period) + UL Control Area

[0128] - DL Control Area + GP + UL Area

[0129] DL Area: (i) DL Data Area, (ii) DL Control Area + DL Data Area

[0130] UL Area: (i) UL Data Area, (ii) UL Data Area + UL Control Area

[0131] In the DL control area, PDCCH can be transmitted, and in the DL data area, PDSCH (physical downlink shared channel) can be transmitted. In the UL control area, PUCCH (physical uplink control channel) can be transmitted, and in the UL data area, PUSCH (physical uplink shared channel) can be transmitted. In PDCCH, DCI (Downlink Control Information), such as DL data scheduling information and UL data scheduling information, can be transmitted. In PUCCH, UCI (Uplink Control Information), such as ACK / NACK (Positive Acknowledgement / Negative Acknowledgement) information for DL ​​data, CSI (Channel State Information) information, and SR (Scheduling Request), can be transmitted. GP provides a time gap during the process of the base station and the terminal switching from transmit mode to receive mode or from receive mode to transmit mode. Within a subframe, some symbols at the point of transition from DL to UL can be set as GP.

[0132] Analog Beamforming #1

[0133] In millimeter wave (mmW), the shorter wavelength allows for the installation of multiple antenna elements within the same area. Specifically, in the 30 GHz band, the wavelength is 1 cm, making it possible to install a total of 100 antenna elements in a 2-dimensional array form with a spacing of 0.5 wavelengths (lambda) on a 5 by 5 cm panel. Therefore, in mmW, multiple antenna elements are used to increase beamforming (BF) gain, thereby increasing coverage or throughput.

[0134] In this case, if a transceiver unit (TXRU) is equipped to allow for transmission power and phase control for each antenna element, independent beamforming for each frequency resource becomes possible. However, installing TXRUs for all 100 or so antenna elements presents a problem of low cost-effectiveness. Therefore, a method is being considered in which multiple antenna elements are mapped to a single TXRU and the beam direction is adjusted using an analog phase shifter. This analog beamforming method has the disadvantage of being unable to perform frequency-selective beamforming because it can only create a single beam direction across the entire band.

[0135] A hybrid beamforming (hybrid BF) can be considered as an intermediate form between digital beamforming (Digital BF) and analog beamforming (analog BF), having B TXRUs, which is fewer than Q antenna elements. In this case, although there are differences depending on the connection method between B TXRUs and Q antenna elements, the number of beam directions that can be transmitted simultaneously is limited to B or fewer.

[0136] Analog Beamforming #2

[0137] In NR systems, when multiple antennas are used, hybrid beamforming techniques combining digital and analog beamforming are emerging. In this case, analog beamforming (or RF beamforming) performs precoding (or combining) at the RF stage, which has the advantage of achieving performance close to that of digital beamforming while reducing the number of RF chains and D / A (or A / D) converters. For convenience, the above hybrid beamforming structure can be represented by N TXRUs and M physical antennas. Then, digital beamforming for L data layers to be transmitted at the transmitter can be represented as an N by L matrix, and subsequently, the converted N digital signals pass through the TXRUs to be converted into analog signals, after which analog beamforming represented as an M by N matrix is ​​applied.

[0138] System information of the NR system can be transmitted via broadcasting. In this case, analog beams belonging to different antenna panels within a single symbol can be transmitted simultaneously, and a method is being discussed to introduce a Beam Reference Signal (BRS), which is a reference signal (RS) transmitted by applying a single analog beam (corresponding to a specific antenna panel) to measure the channel for each analog beam. The BRS can be defined for multiple antenna ports, and each antenna port of the BRS can correspond to a single analog beam. In this case, unlike the BRS, the synchronization signal or xPBCH can be transmitted by applying all analog beams within an analog beam group so that any terminal can receive it well.

[0139] In NR, the synchronization signal block (SSB, or may also be referred to as the synchronization signal and physical broadcast channel: SS / PBCH) in the time domain may consist of four OFDM symbols numbered in ascending order from 0 to 3 within the synchronization signal block, and the PBCH associated with the primary synchronization signal (PSS), secondary synchronization signal (SSS), and demodulation reference signal (DMRS) may be mapped to the symbols. As previously mentioned, the synchronization signal block may also be referred to as the SS / PBCH block.

[0140] In NR, multiple synchronization signal blocks can be transmitted at different times, and since an SSB can be used to perform initial access (IA), serving cell measurement, etc., it is desirable for the SSB to be transmitted first when transmission times and resources overlap with other signals. To this end, the network can broadcast the transmission time and resource information of the SSB or indicate it through UE-specific RRC signaling.

[0141] Meanwhile, beam-based transmission and reception operations can be performed in NR. If the reception performance of the current serving beam deteriorates, a process to find a new beam can be performed through a process called beam failure recovery (BFR).

[0142] Since BFR is not a process that declares an error or failure regarding the link between the network and the terminal, it can be assumed that the connection with the current serving cell is maintained even when the BFR process is performed. During the BFR process, measurements are taken on different beams configured by the network (beams can be expressed as CSI-RS ports or SSB (synchronization signal block) indices, etc.), and the best beam for the terminal can be selected. The terminal can proceed with the BFR process by performing the RACH process associated with the beam for which the measurement results are good.

[0143] Now, the Transmission Configuration Indicator (TCI) state is described. The TCI state can be configured per core set of the control channel, and parameters for determining the reception (Rx) beam of the terminal can be determined based on the TCI state.

[0144] For each downlink bandwidth portion (DL BWP) of a serving cell, the terminal may be configured with three or fewer core sets. Additionally, for each core set, the terminal may be provided with the following information.

[0145] 1) Coreset index p (e.g., one of 0 to 11, in which case the index of each coreset can be uniquely determined in the BWPs of a single serving cell),

[0146] 2) PDCCH DM-RS Scrambled Sequence Initialization Value,

[0147] 3) Interval of the core set in the time domain (can be given in symbol units),

[0148] 4) Resource block set,

[0149] 5) CCE-to-REG mapping parameters,

[0150] 6) Antenna port quasi-co-location (QCL) representing the quasi-co-location information of the DM-RS antenna port for PDCCH reception in each core set (from the set of antenna port quasi-co-locations provided by the upper layer parameter called 'TCI-State'),

[0151] 7) Indication of the existence or non-existence of a transmission configuration indication (TCI) field for a specific DCI format transmitted by PDCCH in the core set, etc.

[0152] QCL is explained. If the characteristics of the channel through which a symbol on one antenna port is transmitted can be inferred from the characteristics of the channel through which a symbol on another antenna port is transmitted, then the two antenna ports can be said to be in a quasi-common location (QCL). For example, if two signals (A and B) are transmitted from the same transmission antenna array with the same / similar spatial filter applied, the two signals may experience the same / similar channel conditions. From the perspective of a receiver, if it receives one of the two signals, it can detect the other signal by utilizing the channel characteristics of the received signal.

[0153] In this sense, the fact that A and B are QCL implies that A and B have undergone similar channel conditions, and therefore, the channel information estimated to detect A may also be useful for detecting B. Here, channel conditions can be defined by, for example, Doppler shift, Doppler spread, average delay, delay spread, spatial reception parameters, etc.

[0154] The 'TCI-State' parameter associates one or two downlink reference signals with the corresponding QCL type (QCL Type: QCL types A, B, C, and D are available; see Table 4).

[0155] [Table 4]

[0156]

[0157] Each 'TCI-State' may include parameters for establishing a quasi-coordinated locality (QCL) relationship between one or two downlink reference signals and the DM-RS port of the PDSCH (or PDCCH) or the CSI-RS port of the CSI-RS resource.

[0158] Meanwhile, in each DL BWP configured for the terminal in a single serving cell, the terminal may be provided with 10 or fewer search space sets. For each search space set, the terminal may be provided with at least one of the following information.

[0159] 1) search space set index s (0≤s<40), 2) association between core set P and search space set s, 3) PDCCH monitoring period and PDCCH monitoring offset (in slots), 4) PDCCH monitoring pattern within a slot (e.g., indicating the first symbol of the core set within the slot for PDCCH monitoring), 5) number of slots in which search space set s exists, 6) number of PDCCH candidates per CCE aggregation level, 7) information indicating whether search space set s is a CSS (common search space) or a USS (UE-specific search space), etc.

[0160] In NR, core set #0 can be configured by the PBCH (or terminal-specific signaling for handover, PSCell configuration, or BWP configuration). The search space (SS) set #0 configured by the PBCH may have different monitoring offsets (e.g., slot offset, symbol offset) for each associated SSB. This may be necessary to minimize the search space occasions that the terminal needs to monitor. Alternatively, it may be necessary to provide a beam sweeping control / data area capable of transmitting control / data according to each beam, so that communication with the terminal can be maintained even when the terminal's best beam changes dynamically.

[0161] Figure 11 illustrates physical channels and general signal transmission.

[0162] Referring to FIG. 11, in a wireless communication system, a terminal receives information from a base station via a downlink (DL) and transmits information to the base station via an uplink (UL). The information transmitted and received by the base station and the terminal includes data and various control information, and various physical channels exist depending on the type / purpose of the information they transmit and receive.

[0163] When the power is turned on again after being off, or when a terminal newly enters a cell, it performs an initial cell search operation, such as synchronizing with the base station (S11). To do this, the terminal receives PSCH (Primary Synchronization Channel) and SSCH (Secondary Synchronization Channel) from the base station to synchronize with the base station and obtain information such as cell ID (cell identity). In addition, the terminal can obtain cell broadcast information by receiving PBCH (Physical Broadcast Channel) from the base station. Furthermore, during the initial cell search phase, the terminal can check the downlink channel status by receiving DL RS (Downlink Reference Signal).

[0164] (Initial) cell search can be described as a procedure in which a terminal acquires time and frequency synchronization with a cell to detect the cell ID of said cell. Cell search may be based on the primary synchronization signal and secondary synchronization signal of said cell, and the PBCH DMRS.

[0165] After completing the initial cell search, the terminal can obtain more specific system information by receiving the PDCCH (Physical Downlink Control Channel) and the corresponding PDSCH (Physical Downlink Control Channel) (S12).

[0166] Subsequently, the terminal may perform a Random Access Procedure to complete the connection to the base station (S13~S16). Specifically, the terminal transmits a preamble through a PRACH (Physical Random Access Channel) (S13) and receives a RAR (Random Access Response) for the preamble through a PDCCH and a corresponding PDSCH (S14). Subsequently, the terminal transmits a PUSCH (Physical Uplink Shared Channel) using scheduling information within the RAR (S15) and may perform a Contention Resolution Procedure such as a PDCCH and a corresponding PDSCH (which can be described as a process of receiving a contention resolution message) (S16).

[0167] A terminal that has performed the procedure described above may subsequently perform PDCCH / PDSCH reception (S17) and PUSCH / PUCCH (Physical Uplink Control Channel) transmission (S18) as a general uplink / downlink signal transmission procedure. The control information transmitted by the terminal to the base station is referred to as UCI (Uplink Control Information). UCI includes HARQ ACK / NACK (Hybrid Automatic Repeat and reQuest Acknowledgement / Negative-ACK), SR (Scheduling Request), CSI (Channel State Information), etc. CSI includes CQI (Channel Quality Indicator), PMI (Precoding Matrix Indicator), RI (Rank Indication), etc. UCI is generally transmitted via PUCCH, but it may be transmitted via PUSCH if control information and data need to be transmitted simultaneously. Additionally, the terminal may transmit UCI non-periodically via PUSCH in response to requests / instructions from the network.

[0168] To enable reasonable battery consumption when BA (bandwidth adaptation) is configured, only one uplink BWP and one downlink BWP or only one downlink / uplink BWP pair for each uplink carrier can be enabled at a time within an active serving cell, and all other BWPs configured in the terminal are disabled. In the disabled BWPs, the terminal does not monitor the PDCCH and does not transmit on the PUCCH, PRACH, and UL-SCH.

[0169] Regarding the BA, the terminal's receive and transmit bandwidths do not need to be as wide as the cell's bandwidth and can be adjusted: the width can be commanded to change (e.g., contracting during periods of low activity to save power), the position in the frequency domain can be shifted (e.g., to increase scheduling flexibility), and the subcarrier spacing can be commanded to change (e.g., to allow different services). A subset of the cell's total cell bandwidth is referred to as the bandwidth part (BWP), and the BA is obtained by setting the BWP(s) to the terminal and informing the terminal of which of the set BWPs is currently active. Once the BA is set, the terminal only needs to monitor the PDCCH on one active BWP. That is, there is no need to monitor the PDCCH across the cell's entire downlink frequency. A BWP inactive timer (independent of the aforementioned DRX inactive timer) is used to switch an active BWP to a default BWP: the timer is restarted when PDCCH decoding is successful, and when the timer expires, switching to the default BWP occurs.

[0170] The sidelink (SL) is explained below.

[0171] The terminal can transmit a relevant signal to another terminal and receive a signal from another terminal through the sidelink channel below.

[0172] (1) Physical Sidelink Broadcast Channel (PSBCH)

[0173] The SL synchronization signal (Sidelink Synchronization Signal, SLSS) is an SL-specific sequence and may include a PSSS (Primary Sidelink Synchronization Signal) and a SSSS (Secondary Sidelink Synchronization Signal). The PSSS may be referred to as the S-PSS (Sidelink Primary Synchronization Signal), and the SSSS may be referred to as the S-SSS (Sidelink Secondary Synchronization Signal). For example, a terminal can detect the initial signal and obtain synchronization using the S-PSS. For example, a terminal can obtain detailed synchronization and detect the synchronization signal ID (identity) using the S-PSS and S-SSSS.

[0174] PSBCH (Physical Sidelink Broadcast Channel) may be a (broadcast) channel through which basic (system) information that the terminal must know first before transmitting or receiving SL signals is transmitted. For example, the basic information may include information related to SLSS, duplex mode (DM), TDD UL / DL (Time Division Duplex Uplink / Downlink) configuration, information related to resource pool, types of applications related to SLSS, subframe offset, broadcast information, etc.

[0175] S-PSS, S-SSS, and PSBCH may be included in a block format that supports periodic transmission (e.g., SL SS (Synchronization Signal) / PSBCH block, hereinafter S-SSB (Sidelink-Synchronization Signal Block)). The S-SSB may have the same numerology (i.e., SCS and CP lengths) as the PSCCH (Physical Sidelink Control Channel) / PSSCH (Physical Sidelink Shared Channel) within the carrier, and the transmission bandwidth may be within a (pre-)configured SL BWP (Sidelink BWP). For example, the bandwidth of the S-SSB may be 11 RB (Resource Blocks). For example, the PSBCH may span across 11 RBs. Additionally, the frequency position of the S-SSB may be (pre-)configured. Therefore, the terminal does not need to perform hypothesis detection at the frequency to discover the S-SSB in the carrier.

[0176] The terminal can generate an S-SS / PSBCH block (i.e., S-SSB), and the terminal can transmit the S-SS / PSBCH block (i.e., S-SSB) by mapping it onto a physical resource.

[0177] (2) Physical Sidelink Control Channel (PSCCH)

[0178] A PSCCH (Physical Sidelink Control Channel) carries a first SCI (Sidelink Control Information) or a first-stage SCI, and a QPSK modulation method is applied. At this time, the first-stage SCI format may include SCI format 1-A. The first SCI may include priority, frequency and time domain resource allocation information, resource reservation period, DMRS pattern, second SCI (Sidelink Control Information) format information, MCS information, and PFSCH (Physical Feedback Shared Channel) overhead information.

[0179] (3) Physical Sidelink Shared Channel (PSSCH)

[0180] PSSCH (Physical Sidelink Shared Channel) can be used to transmit a second SCI or a second-stage SCI indicated by the PSCCH. The second-stage SCI format may include at least one of SCI format 2-X. For example, X may be one of A, B, and C. The second SCI may include HARQ information, source and destination information, cast type, CSI request, communication area information, inter-UE coordination information, etc.

[0181] PSSCH carries sidelink data (e.g., SL-shared channel transport block, SL-SCH TB). At this time, modulation methods such as QPSK (Quadrature Phase Shift Keying), 16 QAM (Quadrature Amplitude Modulation), 64 QAM, and 256 QAM are applied. Modulation symbols generated from codewords created by encoding the TB are mapped to one or more layers (Layer mapping). Each layer is mapped to a resource along with a DMRS (Demodulation Reference Signal) to generate an OFDM symbol signal, which is then transmitted through the corresponding antenna port.

[0182] (4) Physical sidelink feedback channel (PSFCH)

[0183] PSFCH (Physical Sidelink Feedback Channel) carries HARQ feedback information (e.g., NACK information or ACK information) related to PSCCH / PSSCH. A terminal can transmit / report HARQ feedback information to a base station via PUCCH or PUSCH using information generated based on the HARQ feedback information received via PSFCH. Here, HARQ-ACK can be referred to as ACK, ACK information, or positive-ACK information, and HARQ-NACK can be referred to as NACK, NACK information, or negative-ACK information.

[0184] <CSI(channel state information) 관련 동작>

[0185] In NR, CSI-RS (channel state information-reference signal) can be used for time and / or frequency tracking, CSI computation, L1 (layer 1)-RSRP (reference signal received power) computation, and mobility. Here, CSI computation is related to CSI acquisition, and L1-RSRP computation is related to beam management (BM).

[0186] CSI (channel state information) is a general term for information that indicates the quality of the wireless channel (or link) formed between a terminal and an antenna port.

[0187] A base station can transmit CSI-RS to a terminal to determine the characteristics of the downlink channel, and can receive feedback from the terminal regarding channel measurement results based on CSI-RS.

[0188] CSI-RS can be configured for one or more terminals. Different CSI-RS configurations may be provided for each terminal, or the same CSI-RS configuration may be provided for multiple terminals. CSI-RS can support, for example, up to 32 antenna ports. CSI-RS corresponding to N (N is 1 or more) antenna ports can be mapped to N resource element (RE) locations within a time-frequency unit corresponding to one slot and one RB. When N is 2 or more, N-port CSI-RS can be multiplexed using CDM, FDM, and / or TDM methods. A single CDM group may include two antenna ports (CDM2) distinguished based on code resources on the same two adjacent subcarriers (which may be referred to as subcarriers), four antenna ports (CDM4) distinguished based on code resources on the same two adjacent subcarriers and the same two adjacent OFDM slots, or eight antenna ports (CDM8) distinguished based on code resources on the same two adjacent subcarriers and the same four adjacent OFDM slots. If multiple CDM groups exist, the CDM groups may not be mapped to adjacent subcarriers and / or adjacent OFDM symbols. CSI-RS antenna ports may be indexed in the order of CDM group, frequency domain, and time domain. CSI-RS may be mapped to the remaining REs, excluding the RE to which CORESET, DMRS, and SSB are mapped.

[0189] In the frequency domain, CSI-RS can be configured for the entire bandwidth, a portion of the bandwidth (BWP), or a portion of the bandwidth. CSI-RS may be transmitted at each RB within the configured bandwidth (i.e., density=1), or at every second RB (e.g., the even or odd RB) (i.e., density=1 / 2). When CSI-RS is used as a Tracking Reference Signal (TRS), a single-port CSI-RS may be mapped onto three subcarriers in each resource block (i.e., density=3).

[0190] One or more sets of CSI-RS resources may be configured for a terminal in the time domain. Each set of CSI-RS resources may include one or more CSI-RS settings.

[0191] Each CSI-RS resource set can be configured to be periodic, semi-persistent, or non-periodic. For periodic CSI-RS resource sets, the period can be configured to a number of slots ranging from 4 to 640. Additionally, a starting offset value for periodic CSI-RS resource sets can be configured. For semi-persistent CSI-RS resource sets, an offset and period for CSI-RS resource set candidates can be configured. Here, actual CSI-RS transmission can be activated / deactivated based on a MAC Control Element (CE). When a CSI-RS resource set is activated, CSI-RS transmission may be performed according to the configured offset and period until it is deactivated. When a CSI-RS resource set is deactivated, CSI-RS transmission may not be performed until it is explicitly reactivated. For non-periodic CSI-RS transmission, information regarding each CSI-RS resource set may be explicitly provided by the DCI.

[0192] A CSI-IM resource may be configured for Interference Measurement (IM) of a terminal. A CSI-IM resource may contain four REs within one slot and one resource block. The four REs may correspond to two consecutive OFDM symbols and two consecutive subcarriers, or to one OFDM symbol and four consecutive subcarriers. In the frequency domain, the location of the CSI-IM REs may be determined by the CSI-IM configuration. In the time domain, the CSI-IM resource set may be configured periodic, semi-persistent, or non-periodically, similar to the CSI resource set. Generally, transmission may not be performed in the corresponding cell but may be performed in a neighboring cell. As such, the CSI-IM resource may be configured as Zero Power (ZP)-CSI-RS for the terminal.

[0193] ZP-CSI-RS can be configured to be distinct from Non-Zero Power (NZP)-CSI-RS. When a PDSCH is scheduled on a resource containing a CSI-RS RE, the first terminal may assume that rate matching considering the CSI-RS RE is applied to the PDSCH, so that the PDSCH is not mapped to the CSI-RS RE. Here, the CSI-RS may be configured for the first terminal or for the second terminal. In this case, the CSI-RS for the first terminal may be configured as NZP-CSI-RS for the first terminal, and the NZP-CSI-RS resource set may be configured for the first terminal. Meanwhile, the CSI-RS for the second terminal may be configured as ZP-CSI-RS for the first terminal, and the ZP-CSI-RS resource set may be configured for the first terminal. The NZP-CSI-RS resource set can be used for the CSI report configuration of the terminal. The NZP-CSI-RS resource set may also be associated with a CSI-RS or an SSB. Additionally, multiple periodic NZP-CSI-RS resource sets can be configured as TRS resource sets.

[0194] Figure 12 is an example of a CSI-related procedure.

[0195] Referring to FIG. 12, in order to perform one of the aforementioned uses of CSI-RS, the terminal receives configuration information related to CSI from the base station via RRC (radio resource control) signaling (S110).

[0196] The configuration information related to the above CSI may include, for example, at least one of information related to CSI-IM (interference management) resources, information related to CSI measurement configurations, information related to CSI resource configurations, information related to CSI-RS resources, or information related to CSI report configurations.

[0197] i) Information related to CSI-IM resources may include CSI-IM resource information, CSI-IM resource set information, etc. A CSI-IM resource set is identified by a CSI-IM resource set ID (identifier), and one resource set includes at least one CSI-IM resource. Each CSI-IM resource is identified by a CSI-IM resource ID.

[0198] ii) Information related to CSI resource configuration may be represented as 'CSI-ResourceConfig IE'. Information related to CSI resource configuration defines a group including at least one of an NZP (non-zero power) CSI-RS resource set, a CSI-IM resource set, or a CSI-SSB resource set. That is, the information related to CSI resource configuration includes a list of CSI-RS resource sets, and the list of CSI-RS resource sets may include at least one of an NZP CSI-RS resource set list, a CSI-IM resource set list, or a CSI-SSB resource set list. A CSI-RS resource set is identified by a CSI-RS resource set ID, and one resource set includes at least one CSI-RS resource. Each CSI-RS resource is identified by a CSI-RS resource ID.

[0199] The terminal measures the CSI based on the configuration information related to the above CSI (S120).

[0200] The above CSI measurement may include (1) a process of receiving CSI-RS of a terminal (S121) and (2) a process of computing CSI through the received CSI-RS (S122).

[0201] In CSI-RS, the mapping of CSI-RS resource elements (RE) in the time and frequency domains is established by the higher-level parameter, CSI-RS-ResourceMapping.

[0202] The terminal reports the measured CSI to the base station (S130).

[0203] Downlink Transmission and Reception Operation

[0204] FIG. 13 is a flowchart showing an example of downlink transmission and reception operation.

[0205] Referring to FIG. 13, the base station schedules downlink transmissions such as frequency / time resources, a transport layer, a downlink precoder, and an MCS (S1401). In particular, the base station can determine a beam for PDSCH transmission to the terminal through the operations described above.

[0206] The terminal receives downlink control information (DCI: Downlink Control Information) for downlink scheduling (i.e., including scheduling information of the PDSCH) from the base station on the PDCCH (S1402).

[0207] For downlink scheduling, for example, DCI formats 1_0, 1_1, or 1_2 may be used, and in particular, DCI format 1_1 includes the following information: Identifier for DCI formats, Bandwidth part indicator, Frequency domain resource assignment, Time domain resource assignment, PRB bundling size indicator, Rate matching indicator, ZP CSI-RS trigger, Antenna port(s), Transmission configuration indication (TCI), SRS request, DMRS (Demodulation Reference Signal) sequence initialization

[0208] In particular, the number of DMRS ports can be scheduled according to each state indicated in the antenna port(s) field, and Single-user (SU) / Multi-user (MU) transmission scheduling is also possible.

[0209] In addition, the TCI field consists of 3 bits, and the QCL for the DMRS is dynamically indicated by indicating up to 8 TCI states according to the TCI field value.

[0210] The terminal receives downlink data from the base station on the PDSCH (S1403).

[0211] For example, when the terminal detects a PDCCH containing DCI formats 1_0, 1_1, and 1_2, it decodes the PDCCH according to instructions from the corresponding DCI.

[0212] Here, when the terminal receives a PDSCH scheduled by DCI format 1, the terminal may have a DMRS configuration type set by the upper layer parameter 'dmrs-Type', and the DMRS type is used to receive the PDSCH. Additionally, the terminal may have a maximum number of front-loaded DMRA symbols for the PDSCH set by the upper layer parameter 'maxLength'.

[0213] For DMRS configuration type 1, if a single codeword is scheduled for a terminal and an antenna port mapped to an index of {2, 9, 10, 11 or 30} is assigned, or if a single codeword is scheduled and an antenna port mapped to an index of {2, 9, 10, 11 or 12} or {2, 9, 10, 11, 30 or 31} is assigned, or if two codewords are scheduled for a terminal, the terminal assumes that all remaining orthogonal antenna ports are not associated with PDSCH transmission to another terminal.

[0214] Or, for DMRS configuration type 2, if a single codeword is scheduled for a terminal and an antenna port mapped to an index of {2, 10, or 23} is assigned, or if a single codeword is scheduled and an antenna port mapped to an index of {2, 10, 23, or 24} or {2, 10, 23, or 58} is assigned, or if two codewords are scheduled for a terminal, the terminal assumes that all remaining orthogonal antenna ports are not associated with PDSCH transmission to another terminal.

[0215] When a terminal receives PDSCH, the precoding granularity P' can be assumed to be a consecutive resource block in the frequency domain. Here, P' can be one of the values ​​{2, 4, broadband}.

[0216] If P' is determined to be broadband, the terminal does not expect to be scheduled with non-contiguous PRBs, and the terminal can assume that the same precoding is applied to the allocated resources.

[0217] On the other hand, if P' is determined to be either {2 or 4}, the Precoding Resource Block Group (PRG) is divided into P' consecutive PRBs. The actual number of consecutive PRBs within each PRG may be one or more. The UE may assume that the same precoding is applied to consecutive downlink PRBs within the PRG.

[0218] To determine the modulation order, target code rate, and transport block size within the PDSCH, the terminal first reads the 5-bit MCD field within the DCI and determines the modulation order and target code rate. Then, it reads the redundancy version field within the DCI and determines the redundancy version. Then, the terminal determines the transport block size using the number of layers and the total number of allocated PRBs before rate matching.

[0219] Uplink Transmission and Reception Operation

[0220] FIG. 14 is a flowchart showing an example of an uplink transmission and reception operation.

[0221] Referring to FIG. 14, the base station schedules uplink transmissions such as frequency / time resources, a transport layer, an uplink precoder, and an MCS (S1501). In particular, the base station can determine a beam for PUSCH transmission for the terminal through the operations described above.

[0222] The terminal receives a DCI from the base station for uplink scheduling (i.e., including scheduling information for PUSCH) on the PDCCH (S1502).

[0223] For uplink scheduling, for example, DCI formats 0_0, 0_1, or 0_2 may be used, and in particular, DCI format 0_1 ​​includes the following information: DCI format identifier, UL / SUL (Supplementary uplink) indicator, Bandwidth part indicator, Frequency domain resource assignment, Time domain resource assignment, Frequency hopping flag, Modulation and coding scheme (MCS), SRS resource indicator (SRI), Precoding information and number of layers, Antenna port(s), SRS request, DMRS sequence initialization, UL-SCH (Uplink Shared Channel) indicator

[0224] In particular, the SRS resource indicator field may indicate SRS resources configured within the SRS resource set associated with the upper-level parameter 'usage'. Additionally, 'spatialRelationInfo' can be set for each SRS resource, and its value can be one of {CRI, SSB, SRI}.

[0225] The terminal transmits uplink data to the base station over PUSCH (S1503).

[0226] When the terminal detects, for example, a PDCCH containing DCI format 0_0, 0_1, or 0_2, it transmits the corresponding PUSCH according to the instructions given by the DCI.

[0227] For PUSCH transmission, two transmission methods can be supported: codebook-based transmission and non-codebook-based transmission.

[0228] i) When the upper layer parameter 'txConfig' is set to 'codebook', the terminal is configured for codebook-based transmission. Conversely, when the upper layer parameter 'txConfig' is set to 'nonCodebook', the terminal is configured for non-codebook-based transmission. If the upper layer parameter 'txConfig' is not set, the terminal does not expect to be scheduled by DCI format 0_1. When PUSCH is scheduled by DCI format 0_0, the PUSCH transmission is based on a single antenna port.

[0229] In the case of codebook-based transmission, PUSCH can be scheduled by DCI format 0_0, DCI format 0_1, DCI format 0_2, or semi-statically. If this PUSCH is scheduled by DCI format 0_1, the terminal determines the PUSCH transmission precoder based on the SRI, TPMI (Transmit Precoding Matrix Indicator), and transmission rank from the DCI, as given by the SRS resource indicator field and the 'Precoding information and number of layers' field. The TPMI is used to indicate the precoder to be applied across the antenna port and corresponds to the SRS resource selected by the SRI when multiple SRS resources are configured. Or, if a single SRS resource is configured, the TPMI is used to indicate the precoder to be applied across the antenna port and corresponds to that single SRS resource. A transmission precoder is selected from an uplink codebook having the same number of antenna ports as the upper layer parameter 'nrofSRS-Ports'. When the upper layer that the terminal is set to 'codebook' is set to the parameter 'txConfig', at least one SRS resource is configured for the terminal. The SRI indicated in slot n is associated with the most recent transmission of the SRS resource identified by the SRI, where the SRS resource precedes the PDCCH (i.e., slot n) carrying the SRI.

[0230] ii) For non-codebook-based transmission, PUSCH may be scheduled by DCI format 0_0, DCI format 0_1, or semi-statically. When multiple SRS resources are configured, the terminal may determine the PUSCH precoder and transmission rank based on the broadband SRI, where the SRI is given by the SRS resource indicator within the DCI or by the upper-layer parameter 'srs-ResourceIndicator'. The terminal utilizes one or multiple SRS resources for SRS transmission, and the number of SRS resources may be configured for simultaneous transmission within the same RB based on UE capabilities. Only one SRS port is configured per SRS resource. Only one SRS resource can be configured with the upper-layer parameter 'usage' set to 'nonCodebook'. The maximum number of SRS resources that can be configured for non-codebook-based uplink transmission is 4. The SRI indicated in slot n is associated with the most recent transmission of the SRS resource identified by the SRI, where the SRS transmission precedes the PDCCH (i.e., slot n) carrying the SRI.

[0231] <Sidelink Transmission / Reception Operation>

[0232] FIG. 15 illustrates a procedure in which a terminal performs V2X or SL communication depending on the transmission mode.

[0233] The embodiment of FIG. 15 can be combined with various embodiments of the present disclosure. In various embodiments of the present disclosure, the transmission mode may be referred to as a mode or a resource allocation mode. Hereinafter, for convenience of explanation, the transmission mode in LTE may be referred to as an LTE transmission mode, and the transmission mode in NR may be referred to as an NR resource allocation mode.

[0234] For example, FIG. 15(a) illustrates a terminal operation associated with LTE transmission mode 1 or LTE transmission mode 3. Or, for example, FIG. 15(a) illustrates a terminal operation associated with NR resource allocation mode 1. For example, LTE transmission mode 1 can be applied to general SL communication, and LTE transmission mode 3 can be applied to V2X communication.

[0235] For example, FIG. 15(b) illustrates a terminal operation associated with LTE transmission mode 2 or LTE transmission mode 4. Or, for example, FIG. 15(b) illustrates a terminal operation associated with NR resource allocation mode 2.

[0236] Referring to FIG. 15(a), in LTE transmission mode 1, LTE transmission mode 3, or NR resource allocation mode 1, the base station may schedule SL resources to be used by the terminal for SL transmission. For example, in step S8000, the base station may transmit information related to SL resources and / or information related to UL resources to the first terminal. For example, the UL resources may include PUCCH resources and / or PUSCH resources. For example, the UL resources may be resources for reporting SL HARQ feedback to the base station.

[0237] For example, the first terminal may receive information related to a dynamic grant (DG) resource and / or information related to a configured grant (CG) resource from the base station. For example, the CG resource may include a CG type 1 resource or a CG type 2 resource. In this specification, the DG resource may be a resource that the base station sets / assigns to the first terminal via downlink control information (DCI). In this specification, the CG resource may be a (periodic) resource that the base station sets / assigns to the first terminal via DCI and / or RRC messages. For example, in the case of a CG type 1 resource, the base station may transmit an RRC message containing information related to the CG resource to the first terminal. For example, in the case of a CG type 2 resource, the base station may transmit an RRC message containing information related to the CG resource to the first terminal, and the base station may transmit DCI related to the activation or release of the CG resource to the first terminal.

[0238] In step S8010, the first terminal may transmit a PSCCH (e.g., Sidelink Control Information or 1st-stage SCI) to the second terminal based on the resource scheduling. In step S8020, the first terminal may transmit a PSSCH (e.g., 2nd-stage SCI, MAC PDU, data, etc.) associated with the PSCCH to the second terminal. In step S8030, the first terminal may receive a PSFCH associated with the PSCCH / PSSCH from the second terminal. For example, HARQ feedback information (e.g., NACK information or ACK information) may be received from the second terminal via the PSFCH. In step S8040, the first terminal may transmit / report the HARQ feedback information to the base station via a PUCCH or PUSCH. For example, the HARQ feedback information reported to the base station may be information generated by the first terminal based on HARQ feedback information received from the second terminal. For example, the HARQ feedback information reported to the base station may be information generated by the first terminal based on a pre-set rule. For example, the DCI may be a DCI for scheduling SL.

[0239] Referring to FIG. 15(b), in LTE transmission mode 2, LTE transmission mode 4, or NR resource allocation mode 2, the terminal can determine an SL transmission resource within an SL resource set by the base station / network or a preset SL resource. For example, the set SL resource or the preset SL resource may be a resource pool. For example, the terminal may autonomously select or schedule a resource for SL transmission. For example, the terminal may perform SL communication by selecting a resource itself within a set resource pool. For example, the terminal may select a resource itself within a selection window by performing a sensing and resource (re)selection procedure. For example, the sensing may be performed on a subchannel basis. For example, in step S8010, the first terminal, which has selected a resource itself within the resource pool, may use the resource to transmit PSCCH (e.g., SCI (Sidelink Control Information) or 1st-stage SCI) to the second terminal. In step S8020, the first terminal can transmit PSSCH (e.g., 2nd-stage SCI, MAC PDU, data, etc.) associated with the PSCCH to the second terminal. In step S8030, the first terminal can receive PSFCH associated with the PSCCH / PSSCH from the second terminal.

[0240] Referring to FIG. 15 (a) or (b), for example, the first terminal may transmit an SCI to the second terminal over the PSCCH. Or, for example, the first terminal may transmit two consecutive SCIs (e.g., 2-stage SCIs) to the second terminal over the PSCCH and / or PSSCH. In this case, the second terminal may decode the two consecutive SCIs (e.g., 2-stage SCIs) to receive the PSSCH from the first terminal. In this specification, an SCI transmitted over the PSCCH may be referred to as the 1st SCI, the first SCI, the 1st-stage SCI, or the 1st-stage SCI format, and an SCI transmitted over the PSSCH may be referred to as the 2nd SCI, the second SCI, the 2nd-stage SCI, or the 2nd-stage SCI format. For example, a 1st-stage SCI format may include SCI format 1-A, and a 2nd-stage SCI format may include SCI format 2-A and / or SCI format 2-B.

[0241] Referring to FIG. 15 (a) or (b), in step S8030, the first terminal can receive PSFCH. For example, the first terminal and the second terminal can determine a PSFCH resource, and the second terminal can use the PSFCH resource to transmit HARQ feedback to the first terminal.

[0242] Referring to FIG. 15(a), in step S8040, the first terminal can transmit SL HARQ feedback to the base station via PUCCH and / or PUSCH.

[0243] <Cast Type>

[0244] Figure 16 shows three types of casts.

[0245] The embodiment of FIG. 16 can be combined with various embodiments of the present disclosure.

[0246] Specifically, FIG. 16(a) represents a broadcast type SL communication, FIG. 16(b) represents a unicast type SL communication, and FIG. 16(c) represents a group cast type SL communication. In the case of a unicast type SL communication, a terminal can perform one-to-one communication with another terminal. In the case of a group cast type SL communication, a terminal can perform SL communication with one or more terminals within the group to which it belongs. In various embodiments of the present disclosure, SL group cast communication may be replaced with SL multicast communication, SL one-to-many communication, etc.

[0247] Channel Coding

[0248] To enable the receiver to correct errors experienced by the wireless signal in the wireless channel, the transmitter codes the information to be sent using a forward error correction code before transmission. At the receiver, the received signal is demodulated, and the transmitted information is restored after undergoing the decoding process of the error correction code. During this decoding process, errors in the received signal caused by the wireless channel are corrected.

[0249] The signal processing process at the transmission end may include, for example, adding a cyclic redundancy check (CRC) to the transport block, code block segmentation and code block CRC attachment, channel coding, rate matching, and code block concatenation.

[0250] In actual communication systems, for the convenience of implementation, transport blocks exceeding a certain size are divided into multiple smaller data blocks for encoding. These divided smaller data blocks are called code blocks. While code blocks generally have the same size, one of the multiple code blocks may have a different size due to the size limitations of the channel encoder's internal interleaver. After undergoing an error-correcting encoding process in units of code blocks with a fixed interleaver size, interleaving is performed to reduce the impact of burst errors that occur during transmission over the wireless channel. Finally, the code is mapped to the actual wireless resources and transmitted. Since the amount of wireless resources used during actual transmission is constant, rate matching must be performed on the encoded code blocks to match this. Generally, rate matching is achieved through puncturing or repetition. For example, if the amount of wireless resources, i.e., the number of transmission bits that can be transmitted by said wireless resources, is M, and the coded bit sequence, i.e., the number of output bits of the encoder, is N, then if M and N are different, rate matching is performed to adjust the length of the coded bit sequence to match M. If M > N, all or part of the bits of the coded bit sequence are repeated so that the length of the rate-matched sequence becomes equal to M. M <N이면, 레이트 매칭된 시퀀스의 길이가 M과 같아지도록, 코딩된 비트 시퀀스의 비트들 중 일부가 펑처링되며, 펑처링된 비트는 전송에서 제외된다.

[0251] In other words, in a wireless communication system, the transmitting end encodes the data to be transmitted using channel coding with a specific code rate, and then adjusts the code rate of the data to be transmitted through a rate matching process consisting of puncturing and repetition.

[0252] During the channel coding process at the transmission end, a TB CRC is added to the transport block (TB). The TB CRC can be used to check for errors in the decoded TB during the decoding process. Subsequently, if the TB and TB CRC exceed the maximum code block size that the channel encoder can encode, they are divided into multiple code blocks (TB). 'TB + TB CRC' can be divided into multiple CBs based on the input size of the channel encoder. A CB CRC is added to each CB. The CB CRC can be used to check for errors in the decoded CB at the reception end. The CB and CB CRC can be encoded through the channel encoder.

[0253] The signal processing process at the receiving end may include a signal processing process performed in the reverse order of the aforementioned signal processing process. For example, the receiving end may perform decoding on a code block basis using a decoder corresponding to the encoder used for each channel coding at the transmitting end, and may check whether the CRC passes for each code block using the corresponding CRC. The receiving end may finally form a single transmission block from the decoded code blocks and check whether the transmission block passes the CRC.

[0254] Various error correction codes can be used in the encoding / decoding process of wireless communication systems. Although there are various types of error correction codes, the optimal information block sizes for each code are determined based on the code. While many coding schemes are available that offer high capacity information performance at large information block lengths, most of them do not consistently demonstrate good performance across a wide range of information block lengths and code rates. For example, as an alternative to turbo codes, which show minimal further improvement in error rate beyond a certain SNR, a low-density parity check (LDPC) code can be used.

[0255] <AI(artificial intelligence) / ML(machine learning) 프레임워크(Framework)>

[0256] In an AI / ML framework, data collection refers to the process of gathering data from network nodes, management entities, or UEs to serve as a foundation for AI / ML model training, data analysis, and inference. An AI / ML model is a data-driven algorithm that applies machine learning techniques to generate a series of outputs consisting of predictive information and / or decision parameters based on a series of inputs. AI / ML training is an online or offline process of learning features and patterns that best represent the data to train an AI / ML model and obtain the trained model for inference. AI / ML inference is the process of making predictions or guiding decision-making based on the collected data and the AI / ML model using the trained AI / ML model.

[0257] Figure 17 shows general terms related to the functional framework of RAN intelligence.

[0258] Data Collection is a function that provides input data to the Model Training and Model Inference functions. Data preparation specific to AI / ML algorithms (e.g., data pre-processing and cleaning, formatting, and transformation) is not performed within the Data Collection function. Examples of input data may include measurements from users or other network entities, feedback from Actors, and outputs from AI / ML models.

[0259] Training Data: Data required as input for the training function of AI / ML models.

[0260] Inference Data: Data required as input for the inference function of AI / ML models.

[0261] Model training is a function that performs AI / ML model training, validation, and testing to generate model performance metrics as part of the model testing procedure. If necessary, the model training function also handles data preparation (e.g., data preprocessing and cleaning, formatting, and transformation) based on training data provided by the data collection function.

[0262] Model Deployment / Update: Used to initially deploy trained, validated, and tested AI / ML models to the model inference function, or to deliver updated models to the model inference function.

[0263] Model inference is a function that provides AI / ML model inference outputs (e.g., predictions or decisions). The model inference function can provide model performance feedback to the model training function where applicable. If necessary, the model inference function also handles data preparation (e.g., data preprocessing and cleaning, formatting and transformation) based on the inference data provided by the data collection function.

[0264] Output: This is the inference output of the AI / ML model generated by the model inference function.

[0265] Note: Details of the inference output may vary depending on the use case.

[0266] Model Performance Feedback: Can be used to monitor the performance of AI / ML models where possible.

[0267] An Actor is a function that receives the output of a model inference function and triggers or performs the corresponding action. Actors can trigger actions directed toward other entities or themselves.

[0268] Feedback: Information that may be necessary to derive training and inference data, or to monitor the impact on the network through updates to AI / ML model performance, KPIs, and performance counters.

[0269] 6G Communication System

[0270] The 6G (wireless communication) system aims for (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 seen in four aspects: intelligent connectivity, deep connectivity, holographic connectivity, and ubiquitous connectivity, and the 6G system can satisfy the requirements shown in Table 5 below. In other words, Table 5 is a table representing an example of the requirements for a 6G system.

[0271] [Table 5]

[0272]

[0273] 6G systems can have key factors such as enhanced mobile broadband (eMBB), highly stable low-latency communication (URLLC), massive machine communication (mMTC), AI-integrated communication, haptic internet, high throughput, high network capacity, high energy efficiency, low backhaul and access network congestion, and enhanced data security.

[0274] 6G systems are expected to have 50 times higher simultaneous wireless connectivity than 5G wireless communication systems. URLLC, a key feature of 5G, will become an even more dominant technology in 6G communication by providing end-to-end latency of less than 1 ms. Unlike the frequently used area spectrum efficiency, 6G systems will exhibit significantly superior volume spectrum efficiency. 6G systems can provide very long battery life and advanced battery technologies for energy harvesting, meaning mobile devices in 6G systems will not require separate charging. New network characteristics in 6G may include the following:

[0275] Satellite Integrated Network: 6G is expected to be integrated with satellites to provide a global mobile population. Integrating terrestrial, satellite, and airborne networks into a single wireless communication system is crucial for 6G.

[0276] Connected Intelligence: Unlike previous generations of wireless communication systems, 6G is innovative and will update wireless evolution from "connected things" to "connected intelligence." AI can be applied at each stage of the communication process (or at each step of the signal processing described below).

[0277] 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.

[0278] Ubiquitous Super 3D Connectivity: Connectivity to the network and core network functions of drones and very low Earth orbit satellites will create Super 3D connectivity in 6G ubiquitous.

[0279] Some general requirements regarding the new network characteristics of 6G mentioned above may be as follows.

[0280] Small cell networks: The idea of ​​small cell networks was introduced to improve the quality of received signals in cellular systems as a result of increased throughput, energy efficiency, and spectrum efficiency. Consequently, small cell networks are an essential feature of communication systems for 5G and beyond 5G (5GB). Therefore, 6G communication systems also adopt the characteristics of small cell networks.

[0281] Ultra-dense heterogeneous network: Ultra-dense heterogeneous networks will be another important characteristic of 6G communication systems. Multi-tier networks composed of heterogeneous networks improve overall QoS and reduce costs.

[0282] High-capacity backhaul: Backhaul connections are characterized as high-capacity backhaul networks to support high-volume traffic. High-speed fiber optics and free-space optics (FSO) systems can be possible solutions to this problem.

[0283] Radar technology integrated with mobile technology: High-precision localization (or location-based services) through communication is one of the functions of 6G wireless communication systems. Therefore, radar systems will be integrated with 6G networks.

[0284] Softwarization and virtualization: Softwarization and virtualization are two important features that form the basis of the design process in 5GB networks to ensure flexibility, reconfigurability, and programmability. Additionally, billions of devices can be shared across a shared physical infrastructure.

[0285] Artificial Intelligence (AI) is a core implementation technology for 6G systems.

[0286] The most critical and newly introduced technology for 6G systems is AI. AI was not involved in 4G systems. 5G systems will support AI partially or to a very limited extent. However, 6G systems will be supported by AI for complete automation. Advancements in machine learning will create more intelligent networks for real-time communication in 6G. Introducing AI into communications can streamline and enhance real-time data transmission. AI can determine how complex target tasks are performed using numerous analyses. In other words, AI can increase efficiency and reduce processing latency.

[0287] Time-consuming tasks such as handover, network selection, and resource scheduling can be performed instantly by using AI. AI can also play a significant role in M2M, machine-to-human, and human-to-machine communication. Furthermore, AI can enable rapid communication in Brain-Computer Interfaces (BCI). AI-based communication systems can be supported by metamaterials, intelligent structures, intelligent networks, intelligent devices, intelligent cognitive radios, self-sustaining wireless networks, and machine learning.

[0288] Recently, attempts have emerged to integrate AI with wireless communication systems, but these have focused on the application and network layers, particularly deep learning in the fields of wireless resource management and allocation. However, such research is increasingly advancing toward the MAC and physical layers, with attempts to combine deep learning with wireless transmission, particularly at the physical layer. AI-based physical layer transmission refers to the application of signal processing and communication mechanisms based on AI drivers rather than traditional communication frameworks in terms of fundamental signal processing and communication mechanisms. Examples include deep learning-based channel coding and decoding, deep learning-based signal estimation and detection, deep learning-based MIMO mechanisms, and AI-based resource scheduling and allocation.

[0289] Machine learning can be used for channel estimation and channel tracking, and for power allocation and interference cancellation in the physical layer of the downlink (DL). In addition, machine learning can be used for antenna selection, power control, and symbol detection in MIMO systems.

[0290] Machine learning refers to a series of operations for training machines to create machines capable of performing tasks that humans can or find difficult to do. Machine learning requires data and learning models. Data learning methods in machine learning can be broadly classified into three types: supervised learning, unsupervised learning, and reinforcement learning.

[0291] The purpose of neural network training is to minimize output errors. It is a process that repeatedly inputs training data into a neural network, calculates the error between the network's output and the target for the training data, and updates the weights of each node by backpropagating the error from the output layer to the input layer in a direction that reduces the error.

[0292] Supervised learning uses training data with correct answers labeled, whereas unsupervised learning may not have correct answers labeled. That is, for example, in the case of supervised learning regarding data classification, the training data may consist of data where each training data point is labeled with a category. Labeled training data is input into a neural network, and an error can be calculated by comparing the network's output (category) with the labels of the training data. The calculated error is backpropagated within the neural network (i.e., from the output layer to the input layer), and the connection weights of each node in each layer of the neural network can be updated according to this backpropagation. The amount of change in the connection weights of each node being updated can be determined by the learning rate. The neural network's calculations on the input data and the backpropagation of the error can constitute a learning cycle (epoch). The learning rate can be applied differently depending on the number of iterations of the neural network's learning cycle. For example, efficiency can be increased by using a high learning rate in the early stages of neural network training to enable the network to quickly achieve a certain level of performance, and accuracy can be increased by using a low learning rate in the later stages of training.

[0293] The learning method may vary depending on the characteristics of the data. For example, if the goal is to accurately predict data transmitted from the transmitting end at the receiving end in a communication system, it is preferable to perform learning using supervised learning rather than unsupervised learning or reinforcement learning.

[0294] Learning models correspond to the human brain, and while the most basic linear models can be considered, a machine learning paradigm that uses highly complex neural network structures, such as artificial neural networks, as learning models is called deep learning.

[0295] The neural network cores used for learning methods are broadly classified into deep neural networks (DNN), convolutional deep neural networks (CNN), recurrent Boltzmann machines (RNN), and spiking neural networks (SNN).

[0296] Communication for AI Enhancement (C4AI)

[0297] In a split AI / ML model, the system can assign split AI / ML models to devices and servers (networks) to perform split inference in units of divided layers, according to the requirements (computational capability, latency, privacy) of the service (object recognition, augmented reality). In this case, the split model assigned to the device performs data processing via forward propagation up to the split point, and can transmit the intermediate data, which is the output of the processing up to the split point, to the split model assigned to the server.

[0298] For example, a split point can be a point where the inference execution of an AI / ML model is split. For instance, if a split AI / ML model is constructed between a device and a server, the device can perform split inference on the layers up to the split point, while the server can perform split inference on the layers after the split point. The split model assigned to the server can perform split inference using intermediate data received from the split model assigned to the device. The split model assigned to the server can deliver labels, which are the results of the completed split inference, to the device.

[0299] For example, the device may perform inference by receiving labels from a server. When the device performs learning, it may perform a back propagation procedure by receiving the gradient of the loss function for intermediate data from the server. Split inference may be referred to as split inference, partial inference, or other terms having equivalent technical meanings, and may not be limited to specific names.

[0300] Federated Learning

[0301] In new communication systems, base stations and terminals can apply Federated Learning models as a form of learning based on artificial intelligence. Federated Learning can be applied to protect individual privacy, reduce the load on base stations through distributed processing, and decrease traffic between base stations and terminals. Traffic involving local model parameters (e.g., weights and information of deep neural networks) can place a significant burden in wireless communication environments, and considering the aforementioned points, the application of a Federated Learning approach may be necessary. For example, each terminal can transmit parameters of a local model (e.g., weights and information of deep neural networks) learned based on the Federated Learning method to the base station. Each terminal transmits compressed parameters, and the base station can update the global model. Subsequently, the base station can transmit the updated global model to each terminal.

[0302] Synchronization signal design

[0303] Through the synchronization signal, the terminal obtains time / frequency synchronization and a physical cell ID. When the terminal obtains coarse time synchronization through the PSS, operations are performed in the time domain. At this time, since phase noise cannot be compensated for, it is desirable to design a synchronization signal that is robust against phase noise. This is because the variance of the phase noise increases over time. That is, the phase noise of the current sample can be described as the addition of Gaussian noise with a variance proportional to time to the phase noise of the previous sample.

[0304] Differential encoding can be utilized to generate a synchronization signal robust to phase noise.

[0305] Transmission of System Information

[0306] In this specification, system information related to a first frequency band (terahertz frequency band) may be transmitted based on a synchronization signal related to a second frequency band (a frequency band other than the terahertz frequency band). For example, system information (e.g., MIB) of a cell operating in the terahertz frequency band (THz frequency band) (e.g., THz Scell) may be transmitted through a synchronization signal of a cell operating in the 5G frequency band (e.g., LTE / NR Primary Cell (Pcell)).

[0307] Transmitting MIBs via a Physical Broadcast Channel (PBCH) in the THz (terahertz) frequency band can be inefficient in terms of resource utilization. The PBCH is transmitted by performing beam sweeping to ensure transmission to the entire area of ​​the cell. In the case of high-frequency bands, as the beam width narrows, beam sweeping must be performed more frequently to cover the entire area of ​​the cell. Consequently, the time resources required for PBCH transmission increase. Transmitting system information via this method is inefficient when there are not many users within the cell. The same problem applies to paging messages transmitted via beam sweeping. To resolve the above problem, the following operation may be considered.

[0308] If a cell in the THz frequency band operates as a secondary cell (Scell) that aggregates the carriers of an LTE / NR primary cell (Pcell), MIB transmission can be performed using the LTE / NR Pcell. In other words, instead of designing a PBCH in the THz frequency band for MIB transmission, MIBs can be transmitted using LTE / NR Pcell and Scell ​​synchronization channels. In the case of the NR standard, MIB contents for frequency bands above 6 GHz are divided into information generated at the upper layer and information generated at the physical layer. Contents generated at the upper layer include SFN, PDCCH settings for SIB1, cell barring, cell re-selection, and subcarrier spacing, while contents generated at the physical layer include SFN, half-frame indicator, and SSB index.

[0309] The MIB content of a THz Scell ​​that can be transmitted in an LTE / NR Pcell may include content generated at an upper layer (e.g., SFN, PDCCH settings for SIB1, cell barring, cell re-selection). The synchronization channel of a THz Scell ​​may include content generated at the physical layer (e.g., SSB index, half-frame indicator).

[0310] Signal for Beam Search

[0311] In the terahertz (THz) band, severe path loss is expected, and to overcome this, terminals and base stations must use very sharp beams. The use of sharp beams means that terminals and base stations must perform beam control along with beamforming, and the number of beams used becomes very large. Consequently, it takes a very long time to align the transmit and receive beams between the base station and the terminal. Furthermore, if the beam alignment between the base station and the terminal is disrupted due to the movement of the terminal, time is frequently required to realign the beams, which may result in link instability.

[0312] The existing beam search method is performed as follows. A base station provides a beam by utilizing resources defined in the time and frequency domains (e.g., SSB or CSI-RS in NR), and a terminal measures the signal received from the corresponding resources (time and frequency resources). Through the above operation, the base station Tx (transmit) beam and the terminal's Rx (receive) beam are measured.

[0313] According to this existing method, in order to measure a defined beam, the terminal must monitor a specific frequency range at fixed time intervals, and the resources are reserved between the terminal and the base station for beam operation and cannot be used for data transmission and reception.

[0314] To solve the aforementioned problem, fast beam search of the terminal is required. For fast beam search, a method utilizing a Beam Search Signal (BSS) that is spatially separated from the existing downlink signal / channel and transmitted can be considered. The BSS can be transmitted based on a dedicated antenna port (hereinafter simply referred to as a dedicated port) configured for beam search.

[0315] The dedicated port mentioned above may be a port different from the port used for transmitting existing downlink signals / channels (e.g., SSB, PDSCH, etc.). BSS is a term defined for convenience of explanation, and the technical concept according to this embodiment is not limited to the term BSS itself. That is, signals transmitted based on a dedicated port defined / configured for beam search may be included in the technical concept according to this embodiment.

[0316] In the THz band, the number of Tx / Rx beams increases, and the sweeping time required to find the optimal combination of the base station's Tx beam and the UE's Rx beam increases according to the SSB cycle. Furthermore, since the communication environment in the THz band consists of channels with very wide bandwidths, searching for an SSB within the frequency band will also take a very long time.

[0317] With the recent advancement of RF device technology, it has become easier to form multiple beams (e.g., using multiple panels, sub-arrays, and TTD (True time delay)). If a base station transmitting SSB utilizes multiple beams to simultaneously transmit SSB through multiple beams in space, the SSB cycle can be accelerated and the total sweeping time can be reduced.

[0318] <RIS (Reconfigurable Intelligent Surface)>

[0319] Current wireless communication technology can be controlled through endpoint optimization that adapts to the channel environment (H). For example, when optimization is performed at the transmitter and receiver, the transmitter and receiver can increase transmission efficiency by adjusting at least one of beamforming, power control, and adaptive modulation to the channel environment (H) between the transmitter and receiver.

[0320] In this case, the channel environment may be random, uncontrolled, and naturally fixed. That is, in existing communication systems, the channel environment was fixed, and each endpoint was controlled to optimize for the channel environment. Therefore, transmitters and receivers must perform optimization to adapt to the channel and transmit and receive data through this process. However, in environments such as non-line of sight (NLOS) in dead zones or 6G THz, where signal loss is high and multipath is unlikely to exist, it may be difficult to overcome Shannon's Capacity Limit through endpoint optimization alone, and thus it may be difficult to expect the required throughput.

[0321] Considering the above points, communication in the new communication system can be performed based on a Smart Radio Environment. In this case, in the Smart Radio Environment, a Reconfigurable Intelligent Surface (RIS) can be used as a parameter to control the wireless channel, such as a transceiver. For example, for the Smart Radio Environment, Large Intelligent Surfaces (LIS), Smart Large Intelligent Surfaces (SLIS), Intelligent Reflect Surface (IRS), Reconfigurable Meta Surfaces, and other configurations may be used, but are not limited to a specific form.

[0322] In other words, awareness of the wireless channel can be added as a factor used to optimize wireless communication transmission. Through this, it may be possible to reset the channel or overcome Shannon's channel capacity limitations, which are problems that are intractable in existing communication systems.

[0323] Downlink beam management in NR can consist of beam acquisition and beam tracking. Beam acquisition may occur during the initial cell search process or immediately after a beam failure. Beam tracking involves managing the beam connection between the base station and the terminal after beam acquisition through measurement reports and beam reconfiguration to maximize radio quality.

[0324] The following is intended to resolve the problem of slow multi-TRP beam acquisition in conventional technology. In conventional technology, to perform multi-TRP beam acquisition, beam acquisition for a single TRP is generally performed, and then, during the RRC reset process, beam acquisition for the multi-TRP beam link is performed based on terminal measurements through the reception of RRC measurement reports and RRC settings. As mentioned above, conventional technology has a problem in that the initial multi-TRP beam acquisition is slow because it involves a measurement process for multiple TRPs.

[0325] Channel path map

[0326] In relation to 6G communication, the concept of a channel knowledge map (CKM) has been proposed. A CKM is a database for each base station site containing information such as transmitter location tags and / or channel-related information, and can be described as a map that helps a receiver recognize the current environment and communicate. Examples of CKMs include a channel gain map, which is a channel gain map for a target area; a channel shadowing map, which contains information about shadowing areas; and a channel path map, which contains information such as the Angle of Arrival (AoA) / Angle of Departure (AoD), power, phase, and delay for a beam in a target area.

[0327] Figure 18 shows an application example and performance of a channel path map.

[0328] Referring to FIG. 18(a), TX transmission for each terminal is shown in a target area where two terminals are located. Referring to FIG. 18(b), the distribution of the TX beams along one axis of the emission angles in the target area of ​​FIG. 18(a) is shown. Referring to FIG. 18(c), performance using a path map containing information about the distribution in FIG. 18(b) is shown, demonstrating that the average transmission rate can be improved by approaching 'perfect CSI' depending on the 'Loc. err' or location error. The 'Loc-based' method refers to a case where LOS (line of sight) beam information regarding the terminal location is simply used.

[0329] Beam Tracking and Additional Information

[0330] Multimodal information that can be acquired by the terminal can significantly contribute to beam tracking performance. Multimodal information refers to information that the terminal can obtain from sensors, GPS (global positioning system), cameras, radar, LiDAR (light detection and ranging), etc.

[0331] In beam tracking, among various combinations of multimodal information, the combination of, for example, GPS information and images can be of the greatest utility. Additionally, multimodal information may include data obtained from communication channels in different bands (e.g., uplink signal data in the case of a downlink) and historical data from signal processing.

[0332] Beam Management (BM)

[0333] BM procedures refer to L1 (layer 1) / L2 (layer 2) procedures for acquiring and maintaining a set of base station (e.g., gNB, TRP, etc.) and / or terminal (e.g., UE) beams that can be used for downlink (DL) and uplink (UL) transmission / reception, and may include, for example, the following procedures and terms.

[0334] Beam measurement: An operation in which a base station or UE measures the characteristics of a received beamforming signal.

[0335] Beam determination: The operation in which a base station or UE selects its transmit beam (Tx beam) or receive beam (Rx beam).

[0336] Beam sweeping: An operation that covers a spatial area using a transmitting beam and / or a receiving beam for a set time interval in a predetermined manner.

[0337] Beam report: An operation in which the UE reports information about the beam-formed signal based on beam measurements.

[0338] The BM procedure can be divided into (1) a DL BM procedure using an SS (synchronization signal) / PBCH (physical broadcast channel) block (SSB) or CSI-RS, and (2) a UL BM procedure using an SRS (sounding reference signal). Additionally, each BM procedure may include Tx beam sweeping to determine the Tx beam and Rx beam sweeping to determine the Rx beam.

[0339]

[0340] The DL BM procedure may include (1) transmission to beamformed DL RS (reference signals) of the base station (e.g., CSI-RS or SS Block (SSB)) and (2) beam reporting of the terminal.

[0341] Beam reporting may include preferred DL RS ID(identifier)(s) and the corresponding L1-RSRP(Reference Signal Received Power).

[0342] The above DL RS ID may be SSBRI (SSB Resource Indicator) or CRI (CSI-RS Resource Indicator).

[0343] Figure 19 shows an example of transmitting an SSB beam and a CSI-RS beam in a downlink.

[0344] Referring to Fig. 19, the SSB beam and the CSI-RS beam can be used for beam measurements. The measurement metric can be L1-RSRP per resource / block. The SSB is used for relatively coarse beam measurements, and the CSI-RS can be used for relatively fine beam measurements. The SSB can be used for both Tx beam sweeping and Rx beam sweeping.

[0345] Rx beam sweeping using SSBs can be performed as the UE changes the Rx beam across multiple SSB bursts for the same SSBRI. Here, one SS burst includes one or more SSBs, and one set of SS bursts includes one or more SSB bursts.

[0346] <SSB DL BM>

[0347] Figure 20 is a flowchart showing an example of a DL BM procedure using SSB.

[0348] Referring to Fig. 20, the setting for the beam report using SSB is performed during CSI / beam setting in the RRC connected state (RRC connected state, or RRC connected mode).

[0349] The terminal receives from the base station a 'CSI-ResourceConfig IE' containing a 'CSI-SSB-ResourceSetList' containing SSB resources used for BM (S410).

[0350] The following table shows an example of 'CSI-ResourceConfig IE', where BM configuration using SSB is not defined separately, and SSB can be configured like a CSI-RS resource.

[0351] [Table 6]

[0352]

[0353] In Table 6, the 'csi-SSB-ResourceSetList' parameter represents a list of SSB resources used for beam management and reporting in a single CSI-RS resource set. Here, the SSB resource set can be set to {SSBx1, SSBx2, SSBx3, SSBx4, ...}. For example, the SSB index can be defined from 0 to 63.

[0354] The terminal receives SSB resources from the base station based on the above 'csi-SSB-ResourceSetList' (S420).

[0355] When 'CSI-ReportConfig' related to reporting on SSBRI and L1-RSRP is configured, the terminal reports the best SSBRI and the corresponding L1-RSRP to the base station (beam) (S430).

[0356] That is, if the 'reportQuantity' of the above 'CSI-ReportConfig' IE is set to 'ssb-Index-RSRP', the terminal reports the best SSBRI and the corresponding L1-RSRP to the base station.

[0357] And, if the terminal has a CSI-RS resource configured in the same OFDM symbol(s) as the SSB (SS / PBCH Block) and 'QCL-TypeD' is applicable, the terminal can assume that the CSI-RS and SSB are quasi-co-located in terms of 'QCL-TypeD'.

[0358] The above QCL Type D may mean that antenna ports are QCL-connected in terms of spatial reception (spatial Rx) parameters. When a terminal receives multiple DL antenna ports that are in a QCL Type D relationship, it is acceptable to apply the same reception beam. Additionally, the terminal does not expect CSI-RS to be configured in an RE that overlaps with the RE of the SSB.

[0359] <CSI-RS DL BM>

[0360] Regarding the uses of CSI-RS, i) if the 'repetition' parameter is set for a specific CSI-RS resource set and 'trs-Info' is not set, CSI-RS is used for beam management. ii) If the 'repetition' parameter is not set and 'trs-Info' is set, CSI-RS is used for the tracking reference signal (TRS). iii) If the 'repetition' parameter is not set and 'trs-Info' is not set, CSI-RS is used for CSI acquisition.

[0361] The 'repetition' parameter can only be set for CSI-RS resource sets associated with a 'CSI-ReportConfig' set to L1 RSRP or 'No Report (or None)'.

[0362] If a terminal receives a 'CSI-ReportConfig' in which 'reportQuantity' is set to 'cri-RSRP', 'cri-SINR', or 'none', and if a 'CSI-ResourceConfig' for channel measurement (upper layer parameter 'resourcesForChannelMeasurement') includes an 'NZP-CSI-RS-ResourceSet' in which the upper layer parameter 'repetition' is set without including the upper layer parameter 'trs-Info', then the terminal may be configured with only the same number of ports (1-port or 2-port) for all CSI-RS resources within the 'NZP-CSI-RS-ResourceSet' using the upper layer parameter 'nrofPorts'.

[0363] (Upper layer parameter) When 'repetition' is set to 'ON', it relates to the terminal's Rx beam sweeping procedure. In this case, if the terminal receives an 'NZP-CSI-RS-ResourceSet' with 'repetition' set to 'ON', the terminal can assume that at least one CSI-RS resource within the 'NZP-CSI-RS-ResourceSet' is transmitted through the same downlink spatial domain transmission filter. That is, at least one CSI-RS resource within the 'NZP-CSI-RS-ResourceSet' is transmitted through the same Tx beam. Here, at least one CSI-RS resource within the 'NZP-CSI-RS-ResourceSet' may be transmitted with different OFDM symbols. Additionally, the terminal does not expect to receive different periodicities at 'periodicityAndOffset' from all CSI-RS resources within the 'NZP-CSI-RS-ResourceSet'.

[0364] On the other hand, when 'repetition' is set to 'OFF', it relates to the base station's Tx beam sweeping procedure. In this case, if 'repetition' is set to 'OFF', the terminal does not assume that at least one CSI-RS resource within 'NZP-CSI-RS-ResourceSet' is transmitted through the same downlink spatial domain transmission filter. That is, at least one CSI-RS resource within 'NZP-CSI-RS-ResourceSet' is transmitted through different Tx beams.

[0365] Figure 21 shows an example of a DL BM procedure using CSI-RS.

[0366] FIG. 21 (a) shows the Rx beam determination (or refinement) procedure of a terminal, and FIG. 21 (b) shows the Tx beam sweeping procedure of a base station. FIG. 21 (a) is the case where the 'repetition' parameter is set to 'ON', and FIG. 21 (b) is the case where the 'repetition' parameter is set to 'OFF'.

[0367] Figure 22 illustrates the Rx beam determination process of a terminal.

[0368] Referring to FIG. 22, we will examine the Rx beam determination process of the terminal. At this time, FIG. 21 (a) may also be referenced.

[0369] The terminal receives an NZP CSI-RS resource set IE containing an upper layer parameter 'repetition' from the base station via RRC signaling (S610). Here, the 'repetition' parameter is set to 'ON'.

[0370] The terminal repeatedly receives CSI-RS resource(s) within the NZP CSI-RS resource set to 'repetition' 'ON' in different OFDM symbols through the same Tx beam (or DL ​​spatial domain transmission filter) of the base station (S620).

[0371] The terminal determines its own Rx beam (S630).

[0372] The terminal skips the CSI report (S640). In this case, the 'reportQuantity' of the CSI report settings can be set to 'No report (or None)'.

[0373] That is, if the above terminal is set to 'repetition' 'ON', the CSI report can be omitted.

[0374] Figure 23 is a flowchart showing an example of the transmission beam determination process of a base station.

[0375] Referring to FIG. 23, the terminal receives an NZP CSI-RS resource set IE containing an upper layer parameter 'repetition' from the base station via RRC signaling (S710). Here, the 'repetition' parameter is set to 'OFF' and is related to the base station's Tx beam sweeping procedure.

[0376] The terminal receives CSI-RS resources within an NZP CSI-RS resource set with 'repetition' set to 'OFF' through a different Tx beam (DL spatial domain transmission filter) of the base station (S720).

[0377] The terminal selects (or determines) the best beam (S730)

[0378] The terminal reports the ID and associated quality information (e.g., L1-RSRP) for the selected beam to the base station (S740). In this case, the 'reportQuantity' of the CSI report settings can be set to 'CRI + L1-RSRP'.

[0379] That is, when the above terminal transmits CSI-RS for BM, it reports CRI and L1-RSRP for it to the base station.

[0380] FIG. 24 shows an example of resource allocation in the time and frequency domains related to the operation of FIG. 21.

[0381] Referring to FIG. 24, when 'repetition' in the CSI-RS resource set is set to 'ON', multiple CSI-RS resources are used repeatedly by applying the same transmission beam, and when 'repetition' in the CSI-RS resource set is set to 'OFF', different CSI-RS resources can be transmitted to different transmission beams.

[0382] <dl bm 관련 빔 지시 (beam indication)>

[0383] The terminal may receive a list of up to M candidate Transmission Configuration Indication (TCI) states via an RRC message for the purpose of at least Quasi Co-location (QCL) instructions. Here, M may vary depending on the capability of the UE, for example, and may be 64.

[0384] Each TCI state can be configured as a set of RS. Each ID of a DL RS for a space QCL purpose (QCL Type D) within at least the set of RS may refer to one of the DL RS types, such as SSB, P-CSI RS, SP-CSI RS, A-CSI RS, etc.

[0385] At a minimum, the initialization / update of the IDs of DL RS(s) within the RS set used for spatial QCL purposes can be performed at least through explicit signaling. The following table shows an example of a 'TCI-State' IE.

[0386] The 'TCI-State' IE associates one or two DL reference signals (RS) with corresponding quasi-co-location (QCL) types.

[0387] [Table 7]

[0388]

[0389] In Table 7, the 'bwp-Id' parameter indicates the DL BWP where the RS is located, and the 'cell' parameter indicates the serving cell of the UE where the 'referenceSignal' parameter is set. The RS may be located in a serving cell other than the serving cell where the 'TCI-State' is set only when the 'qcl-Type' parameter is set to typeC or typeD. The 'referenceSignal' parameter indicates a reference signal to which QCL information is provided, and specifically, it may indicate a reference antenna port that serves as the source of QCL for the corresponding target antenna port(s) or a reference signal containing such a reference antenna port. The target antenna port(s) may be a CSI-RS, a PDCCH DMRS (demodulation reference signal), or a PDSCH DMRS. For example, to indicate QCL reference RS information for the NZP CSI-RS, the corresponding TCI state ID may be indicated in the NZP CSI-RS resource configuration information. As another example, a TCI status ID can be specified in each CORESET setting to specify QCL reference information for the PDCCH DMRS antenna port(s). As another example, a TCI status ID can be specified via DCI to specify QCL reference information for the PDSCH DMRS antenna port(s).

[0390]

[0391] Depending on the terminal implementation, beam reciprocity (or beam correspondence) between the Tx beam and Rx beam may or may not be established in the UL BM. If reciprocity between the Tx beam and Rx beam is established at both the base station and the terminal, the UL beam pair can be matched through the DL beam pair. However, if reciprocity between the Tx beam and Rx beam is not established at either the base station or the terminal, a process for determining the UL beam pair is required separately from the determination of the DL beam pair.

[0392] In addition, even when both the base station and the terminal maintain beam correspondence, the base station can use the UL BM procedure to determine the DL Tx beam without the terminal requesting a report of the preferred beam.

[0393] UL BM can be performed through beamformed UL SRS transmission, and whether UL BM is applied to an SRS resource set is set by (upper layer parameter) 'usage'. If 'usage' is set to 'BeamManagement(BM)', only one SRS resource can be transmitted to each of multiple SRS resource sets in a given time instance. However, SRS resources in different SRS resource sets that have the same time domain operation within the same BWP can be transmitted simultaneously.

[0394] The terminal may receive one or more Sounding Reference Symbol (SRS) resource sets configured by (upper layer parameter) 'SRS-ResourceSet' or 'SRS-PosResourceSet-r16' (via upper layer signaling, RRC signaling, etc.). For each SRS resource set configured by 'SRS-ResourceSet', the UE may be configured with K (K≥1) SRS resources (upper layer parameter 'SRS-resource'). Here, K is a natural number, and the maximum value of K is indicated by 'SRS_capability'. When the SRS is configured by 'SRS-PosResourceSet-r16', the UE may be configured with K SRS resources, and the maximum value of K may be 16.

[0395] Similar to DL BM, UL BM procedures can also be divided into the terminal's Tx beam sweeping and the base station's Rx beam sweeping.

[0396] Figure 25 shows an example of a UL BM procedure using SRS.

[0397] FIG. 25(a) illustrates the Rx beam determination procedure of a base station. The terminal's transmit beam is fixed, and the base station can find the optimal receive beam by sweeping the receive beam. FIG. 25(b) illustrates the Tx beam sweeping procedure of a terminal. The base station's receive beam is fixed, and the terminal can sweep the transmit beam.

[0398] Figure 26 is a flowchart showing an example of a UL BM procedure using SRS.

[0399] Referring to FIG. 26, the terminal receives RRC signaling (e.g., 'SRS-Config' IE) from the base station that includes a 'usage' parameter (upper layer parameter) set to 'beam management' (S1010).

[0400] Table 8 below shows an example of an 'SRS-Config' Information Element (IE). The 'SRS-Config' IE is used to configure SRS transmission settings or SRS measurements for cross-link interference (CLI). The 'SRS-Config' IE includes a list of SRS resources and a list of 'SRS-ResourceSets'. Each SRS resource set represents a collection of SRS resources.

[0401] The network can trigger the transmission of an SRS resource set using the configured 'aperiodicSRS-ResourceTrigger' (L1 DCI).

[0402] [Table 8]

[0403]

[0404]

[0405]

[0406] 'usage' represents a higher-level parameter indicating whether an SRS resource set is used for beam management, or for codebook-based or non-codebook-based transmission. The 'usage' parameter corresponds to the L1 parameter 'SRS-SetUse'. 'spatialRelationInfo' or 'spatialRelationInfoPos-r16' is a parameter indicating the setting of the spatial relationship between the reference RS and the target SRS. Here, the reference RS can be an SSB, CSI-RS, or SRS corresponding to the L1 parameter 'SRS-SpatialRelationInfo'. If the SRS is set by 'SRS-PosResourceSet-r16', the reference RS can also be a DL PRS (Positioning reference signal). The above 'usage' is set per SRS resource set.

[0407] The terminal determines the Tx beam for the SRS resource to be transmitted based on the 'spatialRelationInfo' included in the 'SRS-Config' IE (S1020). Here, 'spatialRelationInfo' is configured per SRS resource and indicates whether to apply the same beam used in the SSB, CSI-RS, or SRS for each SRS resource. Additionally, 'spatialRelationInfo' may or may not be configured for each SRS resource.

[0408] If 'spatialRelationInfo' is set in the SRS resource, the same beam used in the SSB, CSI-RS, or SRS is applied for transmission. However, if 'spatialRelationInfo' is not set in the SRS resource, the terminal arbitrarily determines a Tx beam and transmits the SRS through the determined Tx beam (S1030).

[0409] More specifically, for P-SRS where 'resourceType' in 'SRS-Resource' or 'SRS-PosResource-r16' is set to 'periodic':

[0410] i) If 'spatialRelationInfo' or 'spatialRelationInfo'Pos-r16 is set to 'SSB / PBCH', the UE transmits the corresponding SRS resource by applying a spatial domain transmission filter identical to (or generated from) the spatial domain reception filter used for receiving SSB / PBCH; or

[0411] ii) If 'spatialRelationInfo' or 'spatialRelationInfoPos-r16' is set to 'CSI-RS', the UE transmits SRS resources by applying the same spatial domain transmission filter used for receiving periodic CSI-RS or semi-persistent (SP) CSI-RS; or

[0412] iii) When 'spatialRelationInfo' or 'spatialRelationInfoPos-r16' is set to 'SRS', the UE transmits the corresponding SRS resources by applying the same spatial domain transmission filter used for periodic SRS transmission.

[0413] iv) When 'spatialRelationInfoPos-r16' is set to 'PRS', the UE transmits the corresponding SRS resource by applying the same spatial domain transmission filter used for receiving the DL PRS.

[0414] Even if 'resourceType' within 'SRS-Resource' or 'SRS-PosResource-r16' is set to 'SP-SRS' or 'AP-SRS', beam determination and transmission operations can be applied similarly to the above.

[0415] Additionally, the terminal may receive or not receive feedback on the SRS from the base station in the following three cases (S1040).

[0416] i) If 'spatialRelationInfo' is set for all SRS resources within an SRS resource set, the terminal transmits the SRS to the beam designated by the base station. For example, if 'spatialRelationInfo' all designate the same SSB, CRI, or SRI, the terminal repeatedly transmits the SRS to the same beam. In this case, the base station may use this to select the Rx beam.

[0417] ii) 'spatialRelationInfo' may not be set for all SRS resources within an SRS resource set. In this case, the terminal can freely switch SRS beams and transmit. That is, this case may be used for the terminal to sweep the Tx beam.

[0418] iii) 'spatialRelationInfo' may be set for only some of the SRS resources within the SRS resource set. In this case, for the set SRS resources, the SRS is transmitted via the designated beam, and for the SRS resources for which 'spatialRelationInfo' is not set, the terminal may arbitrarily apply a Tx beam to transmit.

[0419] <RACH 절차>

[0420] The Random Access Channel procedure is primarily used when accessing the initial network through a base station after cell search, and can be applied to the following use cases.

[0421] 1. Initial access from RRC_IDLE

[0422] 2. Transition from RRC_INACTIVE to RRC_CONNECTED

[0423] 3. RRC Connection Re-establishment

[0424] 4. Handover

[0425] 5. Beam Failure Recovery

[0426] 6. Synchronous reconfiguration

[0427] 7. Timing alignment during SCELL addition

[0428] 8. Disconnection of downlink synchronization (DL out of sync - base station can trigger PDCCH command)

[0429] 9. Disconnection of Uplink Synchronization (UL out of sync)

[0430] 10. The number of scheduling requests sent reached the maximum (SR max transmission reached)

[0431] 11. Uplink data arrival (UL data arrival, no PUCCH set for SR)

[0432] 12. On-demand System Information

[0433] The RACH procedure can be divided into 4-step and 2-step stages.

[0434] Figure 27 illustrates a 4-step RACH procedure.

[0435] Referring to FIG. 27, the base station provides system information to the terminal. The process of receiving system information may be a process in which the UE receives the minimum SIB required for the MIB and RACH processes.

[0436] The subsequent process can be divided into a contention-based RACH process and a contention-free RACH process.

[0437] For example, the contention-based PRACH process is as follows. In FIG. 27, resources for the PRACH preamble, such as frequency, time, and sequence number, are selected before transmitting Msg1 (Message 1), which is the PRACH preamble. For example, in the case of FR2 5G NR standalone mode, a set of acceptable PRACH preambles is selected from the PRACH occasions for the detected SSB. When Msg1 is transmitted, the base station receives it through the RACH window. At this time, the delay is calculated by receiving it in the RACH window by the propagation delay distance between the UE and the gNB, and a RAR (RACH response) is transmitted for UL timing adjustment. Additionally, the base station delivers a UL grant to the UE, and the UE can transmit PUSCH, which is Msg3 (Message 3). Here, the base station transmits Msg4 (message 4) to the UE through the contention resolution process.

[0438] The contention-based PRACH process can typically consist of two stages. It ensures that no collisions occur by providing a specific UE with dedicated random access resources. The UE initiates the PRACH procedure using a dedicated preamble provided by the network. Since PRACH resources are always available, a contention resolution process is not required. Generally, the contention-based PRACH process is used when the network knows in advance that a UE is initiating communication. For example, it can be used in handover procedures or when the network can anticipate uplink data transmission from the UE based on downlink data or signals.

[0439] Figure 28 illustrates a two-step RACH procedure.

[0440] Referring to FIG. 28, the difference between the 2-step RACH procedure and the 4-step RACH procedure is that the PUSCH corresponding to Msg3 (message 3) is transmitted immediately after the transmission of the preamble. Msg B corresponds to the RAR (random access response).

[0441] In the following, we propose a method using a channel path map through a multiple PRACH process to quickly perform initial beam acquisition (also referred to as beam capture) of multiple TRPs.

[0442] Multiple TRPs is a feature in 5G NR that enables a gNB to communicate with a UE (terminal) using two or more TRPs. For example, a base station can communicate with a terminal by operating multiple TRPs, such as TRP A and TRP B.

[0443] In this case, the two TRPs transmit different PDSCHs, and control signals (PDCCH / DCI) for the two PDSCHs can be transmitted through TRP A. Alternatively, TRP A and TRP B transmit two different PDSCHs, and each TRP transmits its own corresponding PDCCH / DCI. In these cases, DL and UL signals can be jointly processed using TRP A and TRP B, which is similar to a COMP (Coordinate MultiPoint) scenario.

[0444] The structure proposed in this disclosure may be similar to a COMP. That is, a database of channel path maps can be shared and operated through coordination among multiple TRPs.

[0445] Figure 29 shows an example of multiple TRPs.

[0446] Referring to FIG. 29, for example, three TRPs, TRP A, B, and C, can share and operate a single channel path map. In order for a UE (terminal) to quickly acquire a beam for multiple TRPs initially for the three TRPs, the UE may be equipped with a multi-panel.

[0447] The above channel path map may include beam information based on the location of the UE. The location of the UE may have an error corresponding to location uncertainty. In this case, despite such error, beam groups can be formed by group-based beamforming to improve transmission and reception stability for line-of-sight (LOS) and non-line-of-sight (NLOS) beams. Multiple TRP beams can be rapidly acquired by quickly estimating the location of the UE at each of TRP A, B, and C and providing database information for the channel path map.

[0448] In the example of FIG. 29, each device can perform the following procedure. This procedure may be referred to as fast beam access (FBA) below. FBA is a procedure / concept that determines the location of a UE through multiple PRACH processes and transmits channel path map information based thereon to the UE to simultaneously establish multiple TRP beam links.

[0449] FIG. 30 illustrates a signaling procedure between a terminal and a base station or TRP (network) in relation to FBA.

[0450] FIG. 30 illustrates an example of signaling between a UE and a network (NW) based on the method proposed in the present disclosure, wherein the UE / NW is merely an example and can be replaced with various other devices as described in the core implementation of a 6G communication system. That is, the UE / NW is for convenience of explanation only and does not limit the scope of the present disclosure.

[0451] Additionally, some step(s) may be omitted depending on the situation and / or settings, etc. In FIG. 30, base station / TRP(s) (BS / TRP(s)) may correspond to any entity belonging to the network, such as a base station, BS (Base Station), node B, TRP, etc.

[0452] Referring to FIG. 30, the UE can perform a reporting procedure related to terminal capability values ​​by receiving a UE capability request (S301) and transmitting a UE capability response (S302). The UE capability request (S301) and the UE capability response (S302) may be referred to as the UE capability procedure. Through this UE capability procedure, range information of terminal capability values ​​for FBA functions can be reported to the network.

[0453] Base station / TRP(s) can provide a setting (setting message) for a function or parameter related to the terminal capability value reported in the UE capability procedure in the form of an MIB / SIB (S303).

[0454] The above configuration (configuration message) may include some or all of the PRACH dedicated resource and TRP information for FBA.

[0455] According to an embodiment, the setting message may include FBA enable information that activates the FBA function.

[0456] Dedicated PRACH resources for FBA can be configured for some of the PRACH resources included in contention-free random access or contention-based random access, or they can be configured independently.

[0457] According to an embodiment, the setting message may set an FBA request mode that instructs the step (S304) of transmitting an FBA request to the base station / TRP(s).

[0458] The FBA request mode can have a value indicating one of, for example, implicit MSG1, explicit MSG1, or MSG3. If implicit MSG1 is indicated, it implicitly indicates that the current RACH process is FBA while FBA enable is currently active, and implies that the PRACH preamble is an FBA request even if there are no dedicated PRACH resources.

[0459] Specifying an explicit MSG1 may mean assigning an FBA-dedicated PRACH to a PRACH-dedicated resource and explicitly indicating that the PRACH preamble belonging to it is an FBA request. Specifying an MSG3 means that the FBA request is sent to MSG3 rather than from the PRACH preamble.

[0460] According to an embodiment, the setting message may set an FBA response mode that directs the base station / TRP(s) to transmit an FBA response (S305). The FBA response mode may have a value directing, for example, MSG2, MSG4, or MSG6.

[0461] According to an embodiment, the setting message may also set a dedicated RNTI for the FBA response.

[0462] The above setting message can be set at any of the L1 / L2 / L3 levels.

[0463] The UE transmits an FBA request (S304). The FBA request can be made through the transmission of PRACH using a PRACH resource for FBA. In this case, PRACH can be said to serve as an intention indicator for FBA.

[0464] If no PRACH resources are allocated for FBA, an FBA request may be transmitted on the first PUSCH following the Random Access Response (RAR). In this case, the UE may transmit UE-side supplementary information to the base station / TRP(s) to improve beam accuracy. The UE-side supplementary information may include some or all of the following information.

[0465] 1) UE rotation class: Enumeration of object types. For example, pedestrian, UAV, vehicle, etc.

[0466] 2) Path loss to TRPs, Doppler information.

[0467] 3) UE AI / ML Model ID.

[0468] This process can be transmitted at the stage instructed in FBA request mode.

[0469] The base station / TRP(s) transmit an FBA response to the UE (S305). For example, the base station / TRP(s) can transmit a CSI-RS beam based on the UE location. By performing group-based beamforming to account for the error in the UE location, the transmission can begin and simultaneously transmit information on the channel path map to the UE. The terminal can receive information on multiple beams through the channel path map and form multiple TRP beam links.

[0470] FBA responses may include some or all of the following information.

[0471] 1) N strong beams with CRS-RS / SSB information elements.

[0472] 2) Path gain, relative AoA(r,θ,φ) to reference beam (previous accessed beam)).

[0473] 3) Propagation characteristics: LOS / NLOS / RIS.

[0474] 4) Path blocking model type: Random process class type with blocking probability

[0475] In the case of a 4-stage RACH, the FBA response can be delivered by the base station / TRP(s) to the UE via the RACH response or MSG4, and in the case of a 2-stage RACH, it can be delivered via MSG2. The UE can receive the FBA response by using a dedicated RNTI configured for the purpose of receiving such FBA responses.

[0476] According to an embodiment, the base station / TRP(s) can signal to the UE that the current RACH response is an FBA response through L2 or L3.

[0477] The UE may transmit additional information on the UE side (S306) to the base station / TRP(s) to increase the accuracy of the beam captured in the AI / ML model. The additional information on the UE side may include some or all of the following information.

[0478] 1) UE rotation class: Enumeration of object types (e.g., pedestrian, UAV, vehicle, etc.)

[0479] 2) Path loss to TRPs, Doppler information.

[0480] 3) UE AI / ML Model ID.

[0481] The above process can be performed in a 2-step / 4-step RACH. The above process can be applied in the same way to the RACH process for a beam failure procedure.

[0482] The aforementioned NW / UE signaling and operation can be implemented by the device described in FIGS. 37–41. For example, NW may correspond to a first wireless device and UE may correspond to a second wireless device, and in some cases, the opposite case may also be considered.

[0483] The above-described NW / UE signaling and operation may be processed by at least one processor (e.g., 102, 202). The above-described NW / UE signaling and operation may be stored in at least one memory (e.g., 104, 204) in the form of an instruction / program (e.g., instruction, executable code) for driving at least one processor (e.g., 102, 202).

[0484] Site-specific beamforming

[0485] Figure 31 shows an example of performing the FBA procedure during the signaling process of 5G NR.

[0486] In Fig. 31, it is assumed that there is a PRACH resource allocation for FBA.

[0487] Referring to FIG. 31, the base station (gNB) provides system information to the terminal (UE) (S311). Through this process, the UE can receive FBA preamble resource allocation. For example, when the UE performs an initial cell search, it can receive separate PRACH resources for FBA based on the MIB / SIB settings.

[0488] The network (gNB) transmits PRACH (more specifically, a preamble via PRACH) simultaneously or sequentially to the first TRPs (e.g., k multiple TRPs) that exceed the RSRP threshold value specified by the network (gNB) (S312). Here, k may be a value greater than or equal to 1. The UE may transmit a preamble using the PRACH resource for FBA, which may mean that the UE requests FBA from the base station.

[0489] The base station performs RACH reception. The base station recognizes the FBA request based on whether it is a PRACH resource allocated for FBA, and can determine the location of the UE by combining the timing advance and the direction information of the SSB beam. At this time, the base station can improve the accuracy of the terminal location by using multiple TRPs.

[0490] The base station checks the location of the UE and refers to the database of the channel path map to provide path information for multiple TRPs to the UE via a random access response message (S313). Through this process, an FBA response can be transmitted.

[0491] The above path information may include all or part of the following: a set of beam info, beam ID of each beam, beam QCL-D, AoA, CSI-RS information, LOS indicator, and AI / ML model ID information. This may correspond to the Msg2 transmission process in the 4-stage RACH process.

[0492] Each TRP of the multiple TRPs transmits a DL beam according to the designation (path information) of this stage, and the UE simultaneously receives DL beams through the multiple TRP beams according to the path information of the channel path map.

[0493] In subsequent UL message transmissions, the UE transmits / transmits FBA information such as rotation, mobility, and AI / ML model information (S314). Through this, the base station can additionally perform fine beam control in group-based beamforming and transmit message 4 (PDCCH) to the terminal (S315).

[0494] Figure 32 illustrates the timeline of the FBA process.

[0495] Referring to Fig. 32, the signaling process between TRP A and the terminal is as follows.

[0496] TRP A performs SSB beam sweeping, and the terminal (UE) selects a first beam that exceeds the RSRP threshold.

[0497] TRP A performs RACH resource allocation by transmitting an SSB for transmitting RACH through the first beam, and the terminal transmits PRACH (message 1) containing an FBA request to TRP A based on this.

[0498] TRP A can estimate the location of a terminal based on the timing advance (TA) value of the PRACH signal transmitted by the terminal relative to the slot boundary. In this case, the estimated location of the terminal has a certain range of location uncertainty.

[0499] A base station controlling TRP A derives beam information for said terminal from a channel path map database (DB) based on the estimated location of said terminal, and then provides an FBA response containing this information to said terminal through a random access response (message 2) of TRP A. The terminal obtains information about the DL beam for TRP A through the FBA response.

[0500] The terminal can perform the aforementioned process similarly with TRP B almost simultaneously. That is, the terminal can transmit PRACH for FBA requests to two TRPs. The terminal can transmit PRACH to the two TRPs (TRP A, TRP B) simultaneously or transmit PRACH within a short time range.

[0501] The base station controlling TRP A and TRP B can estimate the location of the terminal more accurately based on the PRACH signal received by TRP A and the PRACH signal received by TRP B. In other words, the uncertainty regarding the terminal's location can be reduced.

[0502] Based on the terminal location estimated in this way, the base station may derive beam information for the terminal from the channel path map database (DB) and then provide an FBA response containing this information to the terminal through at least one random access response (message 2) among TRP A and TRP B.

[0503] That is, the terminal transmits PRACH (message 1) to indicate its intention regarding the FBA, and the base station provides an FBA response to the terminal through the channel path map DB. Through the information in the FBA response, the terminal obtains information about the DL beam for multiple TRPs.

[0504] Conventionally, there was no allocation of PRACH resources for FBA in 5G, but according to the present proposal, specific PRACH resources among the PRACH resources can be allocated for FBA. In this case, the terminal can perform an FBA request by transmitting a preamble through the specific PRACH resources.

[0505] Figure 33 illustrates a part of the FBA process.

[0506] Fig. 33 may be a process after the process of Fig. 32.

[0507] Referring to Fig. 33, FBA information on the terminal side can be transmitted to the base station via PUCCH / PUSCH (message 3) through FBA information transmission.

[0508] A CSI-RS beam for multiple TRPs, for example, three TRPs, along with CSI-RS resource set and CSI-RS report set information, can be simultaneously transmitted to the terminal.

[0509] Meanwhile, if there is no PRACH resource allocation for FBA, the following process can be performed.

[0510] Figure 34 illustrates terminal operation when there is no PRACH resource allocation for FBA.

[0511] Referring to FIG. 34, the terminal receives system information from the base station and transmits a preamble to the base station via message 1.

[0512] The terminal receives a random access response from the base station via message 2. Message 2 can be received via PDCCH / PDSCH.

[0513] The terminal transmits Message 3 via PUSCH, which may include an FBA request. When there is a PRACH resource allocation for FBA, there is a difference compared to transmitting the preamble (Message 1) through the PRACH resource for FBA.

[0514] That is, the FBA request message can be transmitted via message 3 and may include additional terminal-side information such as the following.

[0515] 1) Terminal rotation class (UE rotation class): Enumeration of object types (pedestrian, UAV, vehicle, etc.),

[0516] 2) Path loss to TRPs, Doppler info,

[0517] 3) Terminal AI / ML Model ID.

[0518] After that, the terminal can receive message 4 from the base station via PDCCH, and the message 4 may include an FBA response.

[0519] However, this scenario is merely one example and can be applied in the same way in 2-stage RACH.

[0520] FIG. 35 shows the effect of the method of the present disclosure.

[0521] That is, Fig. 35 shows the effect compared to the existing method when this proposal is introduced and implemented in 5G NR.

[0522] Referring to FIG. 35, in the conventional method, the terminal must determine the best beam during SSB beam sweeping, whereas in the method of the present disclosure, the terminal selects a first beam that exceeds the RSRP threshold during SSB beam sweeping. This allows for the selection of a beam that receives SSB more quickly.

[0523] In addition, in the conventional method, the terminal does not transmit an FBA request when transmitting Message 1 via PRACH to a single TRP, but in the method of the present disclosure, the terminal transmits an FBA request when transmitting Message 1 via PRACH to multiple TRPs, such as TRP A and B. In this case, TRP A and B can estimate the location of the terminal based on the TA (timing advance) of the received PRACH signal and provide this to the base station. Based on the estimated location of the terminal, the base station derives beam information for TRP A and B from the channel path map DB. Then, this beam information can be provided to the terminal via RAR (Message 2). Specifically, RAR (Message 2) containing the beam information can be provided to the terminal through at least one of TRP A and TRP B.

[0524] Upon receiving such beam information, the terminal can then perform communication using multiple TRPs and the beams indicated by the beam information.

[0525] After that, the terminal requests RRC setup by sending a PUCCH / PUSCH (message 3) containing the terminal's FBA information to the TRP. Then, via PDCCH / PDSCH (message 4), it receives information regarding the RRC setup, i.e., the beams (more precisely estimated / corrected) of multiple TRPs, the CSI-RS resource set, the CSI-RS report set, etc., and notifies the completion of the RRC setup via PUCCH / PUSCH (message 5).

[0526] As shown in FIG. 35, it can be seen that the SSB / CSI-RS measurement and measurement reporting process performed in the conventional method can be omitted in the method of the present disclosure, and multiple TRP beam links can be set up at once.

[0527] When a multi-TRP beam link is established, the probability of beam failure can be significantly reduced, and such a multi-TRP link can be rapidly implemented according to the method of the present disclosure.

[0528] In conventional methods, establishing a multi-TRP beam link requires performing measurements and measurement reporting; however, in the method of the present disclosure, this process is omitted, thereby providing the advantageous effect of enabling fast access.

[0529] FIG. 36 illustrates a method of operation of a terminal according to one embodiment of the present disclosure.

[0530] Referring to FIG. 36, the terminal sends a fast beam access (FBA) request to some of the transmission and reception points (TRPs) (S361).

[0531] The above plurality of TRPs are connected to a single base station, and the single base station can control the plurality of TRPs.

[0532] The above-mentioned TRPs may be k (where k is a natural number greater than or equal to 1) TRPs among the plurality of TRPs, wherein the reference signal received power (RSRP) received from the plurality of TRPs exceeds a set threshold. For example, as described in FIGS. 32 and 33, an FBA request can be sent to two selected TRPs among three TRPs.

[0533] The terminal receives an FBA response from the above-mentioned TRP (S362).

[0534] The above FBA response may include, for example, at least one of information on N beams (N is a natural number greater than or equal to 2) including CRS-RS or SSB information elements, path gain information, Angle of Arrival (AOA) information relative to the reference beam, propagation characteristics, and path blocking model type.

[0535] The above FBA response may be received by being included in a random access response (RAR). According to an embodiment, the random access response may further include information indicating that the random access response includes the FBA response.

[0536] After that, the terminal communicates with the plurality of TRPs based on the FBA response, wherein the FBA response includes information about beams between the plurality of TRPs and the terminal, which is determined based on the location of the terminal (S363).

[0537] The location of the terminal may be estimated by some TRPs based on the TA (timing advance) value of the signal received from the terminal by some TRPs and the direction of the SSB (Synchronization Signal Block) beam transmitted by some TRPs.

[0538] The information regarding the beams between the plurality of TRPs and the terminal may be provided from a database of a channel path map containing information on predetermined beams based on the location of the terminal.

[0539] As described above, the above FBA response may include at least one of the following: set information of beams, beam ID (identity) of each beam, quasi-co-location (QCL) information of the beam, channel state information-reference signal (CSI-RS) information, Angle of Arrival (AOA) information, line of sight (LOS) information, and artificial intelligence (AI) / machine learning (ML) model ID information.

[0540] Based on the information regarding the beams between the plurality of TRPs and the terminal, the terminal can simultaneously receive downlink beams from the plurality of TRPs.

[0541] According to an embodiment, the FBA request may be transmitted to some of the TRPs through a predetermined PRACH (physical random access channel) resource.

[0542] Although not illustrated in FIG. 36, the terminal may further include the step of receiving a terminal capability request and reporting terminal capability information in response to the terminal capability request.

[0543] At this time, the terminal capability information may include range information regarding the FBA (fast beam access) function of the terminal.

[0544] Additionally, although not illustrated in FIG. 36, the terminal may further include a step of receiving a configuration message. At this time, the configuration message may include at least one of a dedicated PRACH resource for FBA, information regarding the plurality of TRPs, FBA enable information indicating whether to enable the FBA function, FBA request mode information indicating the transmission step of an FBA request, FBA response mode information indicating the transmission step of an FBA response, and information for setting a dedicated RNTI (radio network temporary identifier) ​​for the FBA response.

[0545] Although not illustrated in FIG. 36, the terminal may further include a step of transmitting additional information on the side of the terminal. In this case, the additional information on the side of the terminal may include at least one of a terminal rotation class (UE rotation class) indicating an object type, path loss to TRP, Doppler information, and AI / ML model ID information of the terminal.

[0546] FIG. 37 illustrates a wireless device that can be applied to the present specification.

[0547] Referring to FIG. 37, the first wireless device (100) and the second wireless device (200) can transmit and receive wireless signals through various wireless access technologies (e.g., LTE, NR).

[0548] The first wireless device (100) includes at least one processor (102) and at least one memory (104), and may additionally include at least one transceiver (106) and / or at least one antenna (108). The at least one processor (102, hereinafter simply referred to as processor) controls at least one memory (104, hereinafter simply referred to as memory) and / or at least one transceiver (106, hereinafter simply referred to as transceiver or transceiver), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operation sequences disclosed in this document. For example, the processor (102) may process information within the memory (104) to generate a first information / signal, and then transmit a wireless signal containing the first information / signal through the transceiver (106). Additionally, the processor (102) may receive a wireless signal containing a second information / signal through a transceiver (106) and then store information obtained from signal processing of the second information / signal in a memory (104). The memory (104) may be connected to the processor (102) and may store various information related to the operation of the processor (102). For example, the memory (104) may store software code containing instructions for performing some or all of the processes controlled by the processor (102) or for performing the descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams disclosed in this document. Here, the processor (102) and the memory (104) may be part of a communication modem / circuit / chip designed to implement wireless communication technology (e.g., LTE, NR). The transceiver (106) may be connected to the processor (102) and may transmit and / or receive a wireless signal through one or more antennas (108). The transceiver (106) may include a transmitter and / or a receiver. The transceiver (106) may be used in combination with an RF (Radio Frequency) unit.In this specification, a wireless device may refer to a communication modem / circuit / chip.

[0549] The processor (102) connects to a base station through a random access process, transmits a fast beam access (FBA) request to some of the multiple transmit receive points (TRPs) connected to the base station, receives an FBA response from some of the TRPs, and communicates with the multiple TRPs based on the FBA response. At this time, the FBA response includes information about beams between the multiple TRPs and the terminal, which is determined based on the location of the terminal. The specific operation has been described with reference to FIGS. 30 to 36.

[0550] The second 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). The processor (202) controls the memory (204) and / or transceiver (206) and may be configured to implement the descriptions, functions, procedures, proposals, methods and / or sequences of operation disclosed herein. For example, the processor (202) may process information within the memory (204) to generate a third information / signal and then transmit a wireless signal containing the third information / signal through the transceiver (206). Additionally, the processor (202) may receive a wireless signal containing a fourth information / signal through the transceiver (206) and then store information obtained from the signal processing of the fourth information / signal in the memory (204). Memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, memory (204) may store software code containing 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 operation sequences disclosed in this document. Here, the processor (202) and memory (204) may be part of a communication modem / circuit / chip designed to implement wireless communication technology (e.g., LTE, NR). A transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals through one or more antennas (208). The transceiver (206) may include a transmitter and / or receiver. The transceiver (206) may be interchangeable with an RF unit. In this specification, a wireless device may mean a communication modem / circuit / chip.

[0551] A processor (202) receives a fast beam access (FBA) request from a terminal through some of the transmit receive points (TRPs) connected to a base station, transmits an FBA response to the terminal through some of the TRPs, and communicates with the terminal through the multiple TRPs based on the FBA response. At this time, the FBA response includes information about beams between the multiple TRPs and the terminal, which is determined based on the location of the terminal. The specific operation has been described with reference to FIGS. 30 to 36.

[0552] Hereinafter, hardware elements of the wireless device (100, 200) will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors (102, 202). For example, one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). One or more processors (102, 202) may generate one or more Protocol Data Units (PDUs) and / or Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and / or flowcharts of operation disclosed in this document. One or more processors (102, 202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or flowcharts of operation disclosed in this document. One or more processors (102, 202) may generate a signal (e.g., baseband signal) containing a PDU, SDU, message, control information, data, or information according to the functions, procedures, proposals, and / or methods disclosed in this document and provide it to one or more transceivers (106, 206). One or more processors (102, 202) may receive a signal (e.g., baseband signal) from one or more transceivers (106, 206) and may obtain a PDU, SDU, message, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or flowcharts disclosed in this document.

[0553] One or more processors (102, 202) may be referred to as a controller, microcontroller, microprocessor, or microcomputer. One or more processors (102, 202) may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in one or more processors (102, 202). One or more processors (102, 202) may also be implemented as at least one computer-readable medium (CRM) containing instructions based on being executed by at least one processor.

[0554] That is, at least one computer-readable medium (CRM) comprising an instruction based on execution by at least one processor performs the following operations, wherein the operations include the terminal connecting to a base station through a random access process, the terminal transmitting a fast beam access (FBA) request to some of the transmit-receive points (TRPs) connected to the base station, the terminal receiving an FBA response from some of the TRPs, and communicating with the plurality of TRPs based on the FBA response. At this time, the FBA response includes information regarding beams between the plurality of TRPs and the terminal, which is determined based on the location of the terminal. The specific operations have been described with reference to FIGS. 30 to 36.

[0555] The descriptions, functions, procedures, proposals, methods, and / or operation sequences 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. Firmware or software configured to perform the descriptions, functions, procedures, proposals, methods, and / or operation sequences disclosed in this document may be included in one or more processors (102, 202) or stored in one or more memories (104, 204) and driven by one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods, and / or operation sequences disclosed in this document may be implemented using firmware or software in the form of code, instructions, and / or sets of instructions.

[0556] One or more memories (104, 204) may be connected to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, code, instructions, and / or commands. One or more memories (104, 204) may be composed of ROM, RAM, EPROM, flash memory, hard drive, registers, cache memory, computer read storage media, and / or combinations thereof. One or more memories (104, 204) may be located inside and / or outside of one or more processors (102, 202). Additionally, one or more memories (104, 204) may be connected to one or more processors (102, 202) through various technologies such as wired or wireless connections.

[0557] One or more transceivers (106, 206) may transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or operation flowcharts, etc., of this document to one or more other devices. One or more transceivers (106, 206) may receive user data, control information, wireless signals / channels, etc., as mentioned in the descriptions, functions, procedures, proposals, methods and / or operation flowcharts, etc., disclosed in this document from one or more other devices. For example, one or more transceivers (106, 206) may be connected to one or more processors (102, 202) and may transmit and receive wireless signals. For example, one or more processors (102, 202) may control one or more transceivers (106, 206) to transmit user data, control information, or wireless signals to one or more other devices. Additionally, one or more processors (102, 202) may control one or more transceivers (106, 206) to receive user data, control information, or wireless signals from one or more other devices. Additionally, one or more transceivers (106, 206) may be connected to one or more antennas (108, 208), and one or more transceivers (106, 206) may be configured to transmit and receive user data, control information, wireless signals / channels, etc., as described in the descriptions, functions, procedures, proposals, methods, and / or flowcharts of operation disclosed in this document through one or more antennas (108, 208). In this document, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers (106, 206) can convert the received wireless signal / channel, etc. from an RF band signal to a baseband signal in order to process the received user data, control information, wireless signal / channel, etc. using one or more processors (102, 202).One or more transceivers (106, 206) can convert user data, control information, wireless signals / channels, etc. processed using one or more processors (102, 202) from baseband signals to RF band signals. To this end, one or more transceivers (106, 206) may include (analog) oscillators and / or filters.

[0558] FIG. 38 illustrates an example of a signal processing module structure. Here, signal processing may be performed in the processor (102, 202) of FIG. 37.

[0559] Referring to FIG. 38, a transmission device (e.g., a processor, a processor and memory, or a processor and a transceiver) within a terminal or base station may include a scrambler (301), a modulator (302), a layer mapper (303), an antenna port mapper (304), a resource block mapper (305), and a signal generator (306).

[0560] The transmission device can transmit one or more codewords. Each coded bit within a codeword is scrambled by a scrambler (301) and transmitted over a physical channel. A codeword may be referred to as a data sequence and may be equivalent to a transmission block, which is a data block provided by the MAC layer.

[0561] The scrambled bits are modulated into complex-valued modulation symbols by a modulator (302). The modulator (302) can modulate the scrambled bits according to a modulation scheme to arrange them into complex-valued modulation symbols representing positions on a signal constellation. There are no restrictions on the modulation scheme, and m-PSK (m-Phase Shift Keying) or m-QAM (m-Quadrature Amplitude Modulation), etc., may be used for modulating the encoded data. The modulator may be referred to as a modulation mapper.

[0562] The complex modulation symbols above can be mapped to one or more transmission layers by a layer mapper (303). The complex modulation symbols on each layer can be mapped by an antenna port mapper (304) for transmission on an antenna port.

[0563] The resource block mapper (305) can map complex modulation symbols for each antenna port to appropriate resource elements within a virtual resource block allocated for transmission. The resource block mapper can map the virtual resource block to a physical resource block according to an appropriate mapping scheme. The resource block mapper (305) can assign complex modulation symbols for each antenna port to appropriate subcarriers and multiplex them according to the user.

[0564] The signal generator (306) can generate a complex-valued time domain OFDM symbol signal by modulating a complex modulation symbol for each antenna port, i.e., an antenna-specific symbol, using a specific modulation method, such as OFDM (Orthogonal Frequency Division Multiplexing). The signal generator can perform an Inverse Fast Fourier Transform (IFFT) on the antenna-specific symbol, and a Cyclic Prefix (CP) can be inserted into the time domain symbol after the IFFT is performed. The OFDM symbol is transmitted to a receiving device through each transmitting antenna after undergoing digital-to-analog conversion, frequency uplink conversion, etc. The signal generator may include an IFFT module, a CP inserter, a Digital-to-Analog Converter (DAC), a frequency uplink converter, etc.

[0565] FIG. 39 illustrates another example of a signal processing module structure within a transmission device. Here, signal processing can be performed in a processor of a terminal / base station, such as the processor (102, 202) of FIG. 37.

[0566] Referring to FIG. 39, a transmission device (e.g., a processor, a processor and memory, or a processor and a transceiver) within a terminal or base station may include a scrambler (401), a modulator (402), a layer mapper (403), a precoder (404), a resource block mapper (405), and a signal generator (406).

[0567] For one codeword, the transmission device can scramble the coded bits within the codeword by the scrambler (401) and then transmit them through the physical channel.

[0568] The scrambled bits are modulated into complex modulation symbols by a modulator (402). The modulator may modulate the scrambled bits according to a predetermined modulation scheme to arrange them into complex modulation symbols representing positions on a signal constellation. There are no restrictions on the modulation scheme, and pi / 2-BPSK (pi / 2-Binary Phase Shift Keying), m-PSK (m-Phase Shift Keying), or m-QAM (m-Quadrature Amplitude Modulation), etc., may be used for modulating the encoded data.

[0569] The complex modulation symbol can be mapped to one or more transmission layers by the layer mapper (403).

[0570] Complex modulation symbols on each layer can be precoded by a precoder (404) for transmission on an antenna port. Here, the precoder may perform precoding after performing transform precoding on the complex modulation symbols. Alternatively, the precoder may perform precoding without performing transform precoding. The precoder (404) may process the complex modulation symbols in a MIMO manner according to multiple transmission antennas to output antenna-specific symbols and distribute the antenna-specific symbols to the corresponding resource block mapper (405). The output z of the precoder (404) can be obtained by multiplying the output y of the layer mapper (403) by an N-X-M precoding matrix W. Here, N is the number of antenna ports and M is the number of layers.

[0571] The resource block mapper (405) maps the demodulation modulation symbol for each antenna port to the appropriate resource element within the virtual resource block allocated for transmission.

[0572] The resource block mapper (405) can assign complex modulation symbols to appropriate subcarriers and multiplex them according to the user.

[0573] The signal generator (406) can generate a complex-valued time domain Orthogonal Frequency Division Multiplexing (OFDM) symbol signal by modulating a complex modulated symbol using a specific modulation method, such as OFDM. The signal generator (406) can perform an Inverse Fast Fourier Transform (IFFT) on an antenna-specific symbol, and a Cyclic Prefix (CP) can be inserted into the time domain symbol after the IFFT is performed. The OFDM symbol is transmitted to a receiving device through each transmitting antenna after undergoing digital-to-analog conversion, frequency uplink conversion, etc. The signal generator (406) may include an IFFT module, a CP inserter, a Digital-to-Analog Converter (DAC), a frequency uplink converter, etc.

[0574] The signal processing process of the receiving device may be configured as the inverse of the signal processing process of the transmitter. Specifically, the processor of the receiving device performs decoding and demodulation for a wireless signal received from the outside through the antenna port(s) of the transmitter and receiver. The receiving device may include multiple receiving antennas, and each signal received through the receiving antennas is restored to a baseband signal, then undergoes multiplexing and MIMO demodulation to be restored to the data sequence that the transmitting device originally intended to transmit. The receiving device (1820) may include a signal restorer for restoring the received signal to a baseband signal, a multiplexer for combining and multiplexing the received processed signals, and a channel demodulator for demodulating the multiplexed signal sequence into the corresponding codeword. The signal restorer, multiplexer, and channel demodulator may be configured as a single integrated module or as separate independent modules that perform their functions. More specifically, the signal restorer may include an analog-to-digital converter (ADC) that converts an analog signal into a digital signal, a CP remover that removes CP from the digital signal, an FFT module that applies a fast Fourier transform (FFT) to the signal from which CP has been removed to output a frequency domain symbol, and a resource element demapper / equalizer that restores the frequency domain symbol to an antenna-specific symbol. The antenna-specific symbol is restored to a transport layer by a multiplexer, and the transport layer is restored to a codeword that the transmitting device intended to transmit by a channel demodulator.

[0575] FIG. 40 illustrates an example of a wireless communication device according to an embodiment of the present disclosure.

[0576] Referring to FIG. 40, a wireless communication device, for example, a terminal, may include at least one of a processor (2310), such as a digital signal processor (DSP) or a microprocessor, a transceiver (2335), a power management module (2305), an antenna (2340), a battery (2355), a display (2315), a keypad (2320), a Global Positioning System (GPS) chip (2360), a sensor (2365), a memory (2330), a Subscriber Identification Module (SIM) card (2325), a speaker (2345), and a microphone (2350). The antenna and the processor may be multiple.

[0577] The processor (2310) can implement the functions, procedures, and methods described in this specification. The processor (2310) of FIG. 40 may be the processor (102, 202) of FIG. 37.

[0578] The memory (2330) is connected to the processor (2310) and stores information related to the operation of the processor. The memory may be located inside or outside the processor and may be connected to the processor through various technologies such as wired or wireless connections. The memory (2330) of FIG. 40 may be the memory (104, 204) of FIG. 37.

[0579] The user can input various types of information, such as phone numbers, using various techniques, such as pressing a button on the keypad (2320) or using a microphone (2350) to activate sound. The processor (2310) receives and processes the user's information and can perform appropriate functions, such as making a call to the input phone number. In some scenarios, data may be retrieved from a SIM card (2325) or memory (2330) to perform appropriate functions. In some scenarios, the processor (2310) can display various types of information and data on a display (2315) for the user's convenience.

[0580] A transceiver (2335) is connected to a processor (2310) to transmit and / or receive a wireless signal, such as a Radio Frequency (RF) signal. The processor may control the transceiver to initiate communication or to transmit a wireless signal containing various types of information or data, such as voice communication data. The transceiver includes a transmitter and a receiver for transmitting and receiving wireless signals. An antenna (2340) may facilitate the transmission and reception of wireless signals. In some embodiments, when the transceiver receives a wireless signal, it may forward and convert the signal to a baseband frequency for processing by the processor. The processed signal may be processed by various techniques, such as being converted into audible or readable information to be output through a speaker (2345). The transceiver of FIG. 40 may be the transceiver (106, 206) of FIG. 37.

[0581] Although not illustrated in FIG. 40, various components such as a camera and a USB (Universal Serial Bus) port may be additionally included in the terminal. For example, the camera may be connected to the processor (2310).

[0582] FIG. 40 is merely one example of an implementation of a terminal, and is not limited thereto. The terminal is not required to include all the elements of FIG. 40. That is, some components, such as a keypad (2320), a Global Positioning System (GPS) chip (2360), a sensor (2365), a SIM card (2325), etc., may not be essential and, in this case, may not be included in the terminal.

[0583] Figure 41 illustrates another example of a wireless device.

[0584] According to FIG. 41, the wireless device may include at least one processor (102, 202), at least one memory (104, 204), at least one transceiver (106, 206), and one or more antennas (108, 208).

[0585] The difference between the example of the wireless device described in FIG. 37 and the example of the wireless device in FIG. 41 is that in FIG. 37, the processor (102, 202) and the memory (104, 204) are separated, whereas in the example of FIG. 41, the memory (104, 204) is included in the processor (102, 202). That is, the processor and the memory may form a single chipset.

[0586] FIG. 42 illustrates a communication system (1) applicable to the present specification.

[0587] Referring to FIG. 42, the communication system (1) to which this specification applies includes a wireless device, a base station, and a network. Here, the wireless device refers to a device that performs communication using wireless access technology (e.g., 5G NR (New RAT), LTE (Long Term Evolution)) 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 Thing) device (100f), and an AI device / server (400). For example, the vehicle may include a vehicle equipped with wireless communication capabilities, an autonomous vehicle, a vehicle capable of performing inter-vehicle communication, etc. Here, the vehicle may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone). XR devices include AR (Augmented Reality) / VR (Virtual Reality) / MR (Mixed Reality) devices and can be implemented in the form of HMDs (Head-Mounted Devices), HUDs (Head-Up Displays) equipped in vehicles, televisions, smartphones, computers, wearable devices, home appliances, digital signage, vehicles, robots, etc. Portable devices may include smartphones, smartpads, wearable devices (e.g., smartwatches, smart glasses), computers (e.g., laptops, etc.). Home appliances may include TVs, refrigerators, washing machines, etc. IoT devices may include sensors, smart meters, etc. For example, base stations and networks may be implemented as wireless devices, and a specific wireless device (200a) may operate as a base station / network node to other wireless devices.

[0588] Wireless devices (100a to 100f) can be connected to a network (300) through a base station (200). Artificial Intelligence (AI) technology may be applied to the wireless devices (100a to 100f), and the wireless devices (100a to 100f) can be connected to an AI server (400) through the network (300). The network (300) can be configured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g., NR) network. The wireless devices (100a to 100f) may communicate with each other through the base station (200) / network (300), but they may also communicate directly (e.g., sidelink communication) without going through the base station / network. For example, vehicles (100b-1, 100b-2) can communicate directly (e.g., V2V (Vehicle to Vehicle) / V2X (Vehicle to everything) communication). Also, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices (100a to 100f).

[0589] Wireless communication / connection (150a, 150b, 150c) can be established between wireless devices (100a~100f) / base station (200) and base station (200) / base station (200). Here, wireless communication / connection can be achieved through various wireless access technologies (e.g., 5G NR), such as uplink / downlink communication (150a), sidelink communication (150b) (or D2D communication), and inter-base station communication (150c) (e.g., relay, IAB (Integrated Access Backhaul)). Through wireless communication / connection (150a, 150b, 150c), wireless devices and base stations / wireless devices, and base stations and base stations can transmit / receive wireless signals to / from each other. For example, wireless communication / connection (150a, 150b, 150c) can transmit / receive signals through various physical channels. To this end, based on various proposals of this specification, at least some of the following may be performed: 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.

[0590] Meanwhile, NR supports multiple numerologies (or subcarrier spacing (SCS)) to support various 5G services. For example, when the SCS is 15 kHz, it supports a wide area in traditional cellular bands; when the SCS is 30 kHz / 60 kHz, it supports dense-urban, lower latency, and wider carrier bandwidth; and when the SCS is 60 kHz or higher, it supports a bandwidth greater than 24.25 GHz to overcome phase noise.

[0591] The NR frequency band can be defined by two types of frequency ranges (FR1, FR2). The numerical values ​​of the frequency ranges may change; for example, the two types of frequency ranges (FR1, FR2) may be as shown in Table 9 below. For convenience of explanation, among the frequency ranges used in the NR system, FR1 (frequency range 1) may mean "sub 6GHz range" and FR2 (frequency range 2) may mean "above 6GHz range" and may be referred to as millimeter wave (mmW).

[0592] [Table 9]

[0593]

[0594] As described above, the numerical value of the frequency range of the NR system may change. For example, FR1 may include a band of 410 MHz to 7125 MHz as shown in Table 10 below. That is, FR1 may include a frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or higher. For example, the frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or higher included within FR1 may include an unlicensed band. The unlicensed band may be used for various purposes, for example, for communication for vehicles (e.g., autonomous driving).

[0595] [Table 10]

[0596]

[0597] The claims described in this specification may be combined in various ways. For example, the technical features of the method claims in this specification may be combined to be implemented as a device, and the technical features of the device claims in this specification may be combined to be implemented as a method. Furthermore, the technical features of the method claims and the technical features of the device claims in this specification may be combined to be implemented as a device, and the technical features of the method claims and the technical features of the device claims in this specification may be combined to be implemented as a method.

Claims

1. The method is, The terminal connects to the base station through a random access process, and The above terminal transmits a fast beam access (FBA) request to some of the multiple transmit receive points (TRPs) connected to the base station, and The above terminal receives an FBA response from the above part of the TRP, and Communicate with the plurality of TRPs based on the above FBA response, A method characterized in that the above FBA response includes information about beams between the plurality of TRPs and the terminal, which is determined based on the location of the terminal.

2. A method according to claim 1, characterized in that the base station controls the plurality of TRPs.

3. A method according to claim 1, wherein the portion of the TRPs is k (where k is a natural number greater than or equal to 1) TRPs among the plurality of TRPs, wherein the reference signal received power (RSRP) received from the plurality of TRPs exceeds a set threshold.

4. A method according to claim 1, wherein the location of the terminal is estimated by the partial TRP based on the TA (timing advance) value of the signal received by the partial TRP from the terminal and the direction of the SSB (Synchronization Signal Block) beam transmitted by the partial TRP.

5. A method according to claim 1, wherein the information regarding beams between the plurality of TRPs and the terminal is provided from a database of a channel path map containing information on beams predetermined based on the location of the terminal.

6. A method according to claim 1, wherein the FBA response comprises at least one of the following: set information of beams, beam ID (identity) of each beam, quasi co-location (QCL) information of the beam, channel state information-reference signal (CSI-RS) information, Angle of Arrival (AOA) information, line of sight (LOS) information, and artificial intelligence (AI) / machine learning (ML) model ID (identity) information.

7. A method according to claim 1, wherein, based on the information regarding beams between the plurality of TRPs and the terminal, the terminal simultaneously receives downlink beams from the plurality of TRPs.

8. A method according to claim 1, characterized in that the FBA request is transmitted to some of the TRPs through a predetermined PRACH (physical random access channel) resource.

9. In claim 1, the terminal receives a terminal capability request, and The step of reporting terminal capability information in response to the above terminal capability request is further included, A method characterized in that the above terminal capability information includes range information for the FBA (fast beam access) function of the terminal.

10. In claim 1, the terminal further includes the step of receiving a setting message, wherein A method characterized in that the above-described configuration message includes at least one of the following: a dedicated PRACH resource for FBA, information regarding the plurality of TRPs, FBA enable information indicating whether to enable the FBA function, FBA request mode information indicating the transmission step of the FBA request, FBA response mode information indicating the transmission step of the FBA response, and information for setting a dedicated RNTI (radio network temporary identifier) ​​for the FBA response.

11. In claim 1, the above FBA response is, A method characterized by including at least one of information on N beams (N is a natural number greater than or equal to 2) including CRS-RS or SSB information elements, path gain information, Angle of Arrival (AOA) information relative to a reference beam, propagation characteristics, and a path blocking model type.

12. A method according to claim 1, characterized in that the FBA response is received by being included in a random access response (RAR).

13. A method according to claim 12, wherein the random access response further comprises information indicating that the random access response includes the FBA response.

14. In claim 1, the terminal further includes the step of transmitting additional information on the side of the terminal, wherein A method characterized in that the additional information on the side of the terminal includes at least one of a terminal rotation class (UE rotation class) indicating an object type, path loss to the TRP, Doppler information, and AI / ML model ID information of the terminal.

15. The terminal, At least one transmitting and receiving unit; At least one memory; and It includes at least one processor that can be connected to operate with the above at least one memory and the above at least one transceiver, The above at least one memory includes instructions that cause the at least one processor to perform operations based on execution by the at least one processor, wherein The above operations are, The above terminal connects to the base station through a random access process, and The above terminal transmits a fast beam access (FBA) request to some of the multiple transmit receive points (TRPs) connected to the base station, and The above terminal receives an FBA response from the above part of the TRP, and It includes communicating with the plurality of TRPs based on the above FBA response, A terminal characterized in that the above FBA response includes information about beams between the plurality of TRPs and the terminal, which is determined based on the location of the terminal.

16. A terminal according to claim 15, characterized in that the base station controls the plurality of TRPs.

17. A terminal according to claim 15, wherein some of the TRPs are k (where k is a natural number greater than or equal to 1) TRPs among the plurality of TRPs, wherein the reference signal received power (RSRP) received from the plurality of TRPs exceeds a set threshold.

18. A terminal according to claim 15, wherein the location of the terminal is estimated by the partial TRP based on the TA (timing advance) value of the signal received by the partial TRP from the terminal and the direction of the SSB (Synchronization Signal Block) beam transmitted by the partial TRP.

19. A terminal according to claim 15, wherein the information regarding beams between the plurality of TRPs and the terminal is provided from a database of a channel path map containing information on beams predetermined based on the location of the terminal.

20. A terminal according to claim 15, wherein the FBA response comprises at least one of the following: set information of beams, beam ID (identity) of each beam, quasi co-location (QCL) information of the beam, channel state information-reference signal (CSI-RS) information, Angle of Arrival (AOA) information, line of sight (LOS) information, and artificial intelligence (AI) / machine learning (ML) model ID (identity) information.

21. A terminal according to claim 15, characterized in that, based on the information regarding beams between the plurality of TRPs and the terminal, the terminal simultaneously receives downlink beams from the plurality of TRPs.

22. A terminal according to claim 15, characterized in that the FBA request is transmitted to some of the TRPs through a predetermined PRACH (physical random access channel) resource.

23. In claim 15, the terminal receives a request for terminal capability, and The step of reporting terminal capability information in response to the above terminal capability request is further included, A terminal characterized in that the above terminal capability information includes range information for the FBA (fast beam access) function of the terminal.

24. In claim 15, the terminal further includes the step of receiving a setting message, wherein A terminal characterized by the above-mentioned configuration message including at least one of a dedicated PRACH resource for FBA, information regarding the plurality of TRPs, FBA enable information indicating whether to enable the FBA function, FBA request mode information indicating the transmission step of an FBA request, FBA response mode information indicating the transmission step of an FBA response, and information for setting a dedicated RNTI (radio network temporary identifier) ​​for an FBA response.

25. In Clause 15, the above FBA response is, A terminal characterized by including at least one of information on N (N is a natural number greater than or equal to 2) beams including CRS-RS or SSB information elements, path gain information, Angle of Arrival (AOA) information relative to a reference beam, propagation characteristics, and a path blocking model type.

26. A terminal according to claim 15, wherein the FBA response is received by being included in a random access response (RAR).

27. A terminal according to claim 26, wherein the random access response further comprises information indicating that the random access response includes the FBA response.

28. In claim 15, the above operations are, The above terminal further includes the step of transmitting additional information on the side of the terminal, The terminal is characterized by the fact that the additional information on the side of the terminal includes at least one of a terminal rotation class (UE rotation class) indicating an object type, path loss to TRP, Doppler information, and AI / ML model ID information of the terminal.

29. The device is, At least one memory; and It includes at least one processor that can be connected to the above at least one memory to enable operation, The above at least one memory includes instructions that cause the at least one processor to perform operations based on execution by the at least one processor, wherein The above operations are, The terminal connects to the base station through a random access process, and The above terminal transmits a fast beam access (FBA) request to some of the multiple transmit receive points (TRPs) connected to the base station, and The above terminal receives an FBA response from the above part of the TRP, and It includes communicating with the plurality of TRPs based on the above FBA response, A device characterized in that the above FBA response includes information about beams between the plurality of TRPs and the terminal, which is determined based on the location of the terminal.

30. In a computer-readable medium (CRM) storing instructions for operations to be performed by one or more processors, said operations are, The terminal connects to the base station through a random access process, and The above terminal transmits a fast beam access (FBA) request to some of the multiple transmit receive points (TRPs) connected to the base station, and The above terminal receives an FBA response from the above part of the TRP, and It includes communicating with the plurality of TRPs based on the above FBA response, A CRM characterized in that the above FBA response includes information about beams between the plurality of TRPs and the terminal, which is determined based on the location of the terminal.

31. The method is, Some of the multiple TRPs (transmit receive points) connected to the base station receive a fast beam access (FBA) request from the terminal, and The above part of the TRP sends an FBA response to the above terminal, and Based on the above FBA response, the plurality of TRPs communicate with the terminal, A method characterized in that the above FBA response includes information about beams between the plurality of TRPs and the terminal, which is determined based on the location of the terminal. 32.TRP (transmit receive point) is, At least one transmitting and receiving unit; At least one memory; and It includes at least one processor that can be connected to operate with the above at least one memory and the above at least one transceiver, The above at least one memory includes instructions that cause the at least one processor to perform operations based on execution by the at least one processor, wherein The above operations are, The above TRP, which is one of a plurality of TRPs connected to a base station, receives a fast beam access (FBA) request from a terminal, and Send an FBA response to the above terminal, and Based on the above FBA response, the TRP communicates with the terminal, The above FBA response is characterized by including information about beams between the plurality of TRPs and the terminal, which is determined based on the location of the terminal.

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