Method and device for performing random access procedure in wireless mobile communication system

Abstract

The present embodiments relate to a method for a terminal to perform a random access procedure, the method comprising the steps of: receiving random access channel (RACH) configuration information; determining one RACH occasion (RO) among a plurality of ROs configured on the basis of the RACH configuration information; and transmitting a random access preamble in the determined RO, wherein the RACH configuration information includes first RACH configuration information for configuring at least one first RO and second RACH configuration information for configuring at least one second RO for a subband full duplex (SBFD).

Description

Method and device for performing a random access procedure in a wireless mobile communication system

[0001] The present embodiments propose a method and apparatus for performing a random access procedure in a wireless mobile communication system in a next-generation wireless access network (in this disclosure, “5G,” “NR [New Radio],” “5G-Advanced,” “6G,” or a subsequent 3GPP wireless access network).

[0002] TDD (Time Division Duplex) is a duplexing method widely used in commercial New Radio (NR) and 5G mobile communication systems. In TDD, time-slot radio resources are divided into downlink and uplink slots. Typically, downlink slots are distributed at a higher rate than uplink slots, depending on the distribution ratio of uplink to downlink traffic. However, this limitation of uplink slots negatively impacts coverage and latency. Full duplex communication has recently attracted attention as a technology to address these issues.

[0003] Even in these full-duplex environments, particularly those where full-duplex communication is structured on a subband basis, symbol- or slot-by-symbol basis, random access procedures can still be performed. In this context, specific designs are needed to allocate resources for random access and transmit and receive random access preambles, especially when full-duplex communication is structured in various ways, symbol-by-slot.

[0004] Embodiments of the present disclosure can provide a method and device for performing a random access procedure in a wireless mobile communication system.

[0005] In one aspect, the present embodiments may provide a method for a terminal to perform a random access procedure, the method comprising: receiving random access channel (RACH) configuration information; determining one of a plurality of random access channel occasions (ROs) configured based on the RACH configuration information; and transmitting a random access preamble in the determined RO, wherein the RACH configuration information includes first RACH configuration information for configuring at least one first RO and second RACH configuration information for configuring at least one second RO for subband full duplex (SBFD).

[0006] In another aspect, the present embodiments may provide a method for a base station to perform a random access procedure, the method comprising the steps of transmitting random access channel (RACH) configuration information, and receiving a random access preamble in one of a plurality of random access channel occasions (ROs) configured based on the RACH configuration information, wherein the RACH configuration information includes first RACH configuration information for configuring at least one first RO and second RACH configuration information for configuring at least one second RO for subband full duplex (SBFD).

[0007] In another aspect, the present embodiments may provide a terminal for performing a random access procedure, the terminal including a transmitter, a receiver, and a control unit for controlling operations of the transmitter and the receiver, wherein the control unit receives random access channel (RACH) configuration information, determines one of a plurality of random access channel occasions (ROs) configured based on the RACH configuration information, and transmits a random access preamble in the determined RO, and the RACH configuration information includes first RACH configuration information for configuring at least one first RO and second RACH configuration information for configuring at least one second RO for subband full duplex (SBFD).

[0008] In another aspect, the present embodiments may provide a base station performing a random access procedure, the base station including a transmitter, a receiver, and a control unit for controlling operations of the transmitter and the receiver, wherein the control unit transmits random access channel (RACH) configuration information, and receives a random access preamble in one of a plurality of random access channel occasions (ROs) configured based on the RACH configuration information, and the RACH configuration information includes first RACH configuration information for configuring at least one first RO and second RACH configuration information for configuring at least one second RO for subband full duplex (SBFD).

[0009] According to the present embodiments, a method and device for performing a random access procedure in an environment where full-duplex communication is applied can be provided.

[0010] FIG. 1 is a schematic diagram illustrating the structure of an NR wireless communication system to which the present embodiment can be applied.

[0011] FIG. 2 is a drawing for explaining a frame structure in an NR system to which the present embodiment can be applied.

[0012] FIG. 3 is a diagram for explaining a resource grid supported by a wireless access technology to which the present embodiment can be applied.

[0013] FIG. 4 is a diagram for explaining a bandwidth part supported by a wireless access technology to which the present embodiment can be applied.

[0014] FIG. 5 is a diagram illustrating an example of a synchronization signal block in a wireless access technology to which the present embodiment can be applied.

[0015] FIG. 6 is a diagram for explaining a random access procedure in a wireless access technology to which the present embodiment can be applied.

[0016] Figure 7 is a drawing for explaining CORESET.

[0017] FIG. 8 is a diagram illustrating an example in which an uplink subband is set in an arbitrary downlink slot according to one embodiment.

[0018] FIG. 9 is a diagram illustrating another example in which an uplink subband is set in an arbitrary downlink slot according to one embodiment.

[0019] FIG. 10 is a diagram illustrating a procedure for a terminal to perform a random access procedure according to one embodiment.

[0020] FIG. 11 is a diagram illustrating a procedure for a base station to perform a random access procedure according to one embodiment.

[0021] Fig. 12 is a drawing showing the configuration of a terminal according to another embodiment.

[0022] Fig. 13 is a drawing showing the configuration of a base station according to another embodiment.

[0023] Hereinafter, some embodiments of the present disclosure will be described in detail with reference to exemplary drawings. When adding reference numerals to components in each drawing, identical components may have the same numerals as much as possible even if they are shown in different drawings. In addition, when describing the present embodiments, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the technical idea of ​​the present invention, the detailed description may be omitted. When "includes," "has," "consists of," etc. are used in this specification, other parts may be added unless "only" is used. When a component is expressed in the singular, it may include a case in which the plural is included unless specifically stated otherwise.

[0024] Additionally, terms such as first, second, A, B, (a), (b), etc. may be used to describe components of the present disclosure. These terms are only intended to distinguish the components from other components, and the nature, order, sequence, or number of the components are not limited by the terms.

[0025] In a description of the positional relationship of components, when it is described that two or more components are "connected," "combined," or "connected," it should be understood that the two or more components may be directly "connected," "combined," or "connected," but that the two or more components may also be further "interposed" with another component to be "connected," "combined," or "connected." Here, the other component may be included in one or more of the two or more components that are "connected," "combined," or "connected" to each other.

[0026] In the description of the temporal flow relationship related to components, operation methods, or manufacturing methods, for example, when the temporal or flow relationship is described as “after”, “following”, “next to”, “before”, etc., it may also include cases where it is not continuous, unless “immediately” or “directly” is used.

[0027] Meanwhile, when numerical values ​​or corresponding information (e.g., levels, etc.) for components are mentioned, even without separate explicit description, the numerical values ​​or corresponding information may be interpreted as including an error range that may occur due to various factors (e.g., process factors, internal or external impact, noise, etc.).

[0028] The wireless communication system in this specification refers to a system for providing various communication services such as voice, data packets, etc. using wireless resources, and may include a terminal, a base station, or a core network.

[0029] The embodiments disclosed below can be applied to wireless communication systems using various wireless access technologies. For example, the embodiments can be applied to various wireless access technologies such as CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), SC-FDMA (single carrier frequency division multiple access), or NOMA (non-orthogonal multiple access). In addition, the wireless access technology may not only refer to a specific access technology, but also to each generation of communication technology established by various communication agreement organizations such as 3GPP, 3GPP2, WiFi, Bluetooth, IEEE, and ITU. For example, CDMA can be implemented with wireless technologies such as UTRA (universal terrestrial radio access) or CDMA2000. TDMA can be implemented with wireless technologies such as GSM (global system for mobile communications) / GPRS (general packet radio service) / EDGE (enhanced data rates for GSM evolution). OFDMA can be implemented in wireless technologies such as IEEE (Institute of Electrical and Electronics Engineers) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and E-UTRA (evolved UTRA). IEEE 802.16m is an evolution of IEEE 802.16e and provides backward compatibility with systems based on IEEE 802.16e.UTRA is part of UMTS (universal mobile telecommunications system). 3GPP (3rd generation partnership project) LTE (long term evolution) is part of E-UMTS (evolved UMTS) that uses E-UTRA (evolved-UMTSterrestrial radio access), employing OFDMA in the downlink and SC-FDMA in the uplink. Thus, the present embodiments can be applied to currently disclosed or commercialized wireless access technologies, as well as wireless access technologies currently under development or to be developed in the future.

[0030] Meanwhile, the term "terminal" in this specification is a comprehensive concept that refers to a device that includes a wireless communication module that performs communication with a base station in a wireless communication system, and should be interpreted as a concept that includes not only UE (User Equipment) in WCDMA, LTE, NR, HSPA, and IMT-2020 (5G or New Radio), but also MS (Mobile Station), UT (User Terminal), SS (Subscriber Station), and wireless device in GSM. In addition, the terminal may be a user portable device such as a smartphone depending on the usage type, and in a V2X communication system, it may mean a vehicle, a device including a wireless communication module in the vehicle, etc. In addition, in the case of a Machine Type Communication system, it may mean an MTC terminal, M2M terminal, URLLC terminal, etc. that is equipped with a communication module to perform machine type communication.

[0031] The base station or cell in this specification refers to an end that communicates with a terminal in terms of a network, and includes various coverage areas such as Node-B, eNB (evolved Node-B), gNB (gNode-B), LPN (Low Power Node), Sector, Site, various types of antennas, BTS (Base Transceiver System), Access Point, Point (e.g., Transmission Point, Reception Point, Transmission / Reception Point), Relay Node, Mega Cell, Macro Cell, Micro Cell, Pico Cell, Femto Cell, RRH (Remote Radio Head), RU (Radio Unit), and Small Cell. In addition, a cell may mean including a BWP (Bandwidth Part) in the frequency domain. For example, a serving cell may mean an Activation BWP of a terminal.

[0032] Since the various cells listed above have a base station that controls one or more cells, the base station can be interpreted in two meanings. 1) It can be a device itself that provides a mega cell, macro cell, micro cell, pico cell, femto cell, or small cell in relation to a wireless area, or 2) it can indicate the wireless area itself. In 1), all devices that provide a given wireless area are controlled by the same entity or that interact to cooperatively configure the wireless area are all indicated as a base station. Depending on how the wireless area is configured, a point, a transceiver point, a transmission point, a reception point, etc. can be an embodiment of a base station. In 2), the wireless area itself that receives or transmits a signal from the perspective of a user terminal or a neighboring base station can also be indicated as a base station.

[0033] In this specification, a cell may mean a component carrier having coverage of a signal transmitted from a transmission / reception point or a transmission / reception point itself.

[0034] Uplink (UL, or uplink) refers to a method of transmitting and receiving data from a terminal to a base station, and downlink (DL, or downlink) refers to a method of transmitting and receiving data from a base station to a terminal. Downlink may refer to communication or a communication path from multiple transmission / reception points to a terminal, and uplink may refer to communication or a communication path from a terminal to multiple transmission / reception points. In this case, in the downlink, the transmitter may be part of the multiple transmission / reception points, and the receiver may be part of the terminal. In addition, in the uplink, the transmitter may be part of the terminal, and the receiver may be part of the multiple transmission / reception points.

[0035] Uplink and downlink transmit and receive control information through control channels such as PDCCH (Physical Downlink Control CHannel) and PUCCH (Physical Uplink Control CHannel), and transmit and receive data by configuring data channels such as PDSCH (Physical Downlink Shared CHannel) and PUSCH (Physical Uplink Shared CHannel). Hereinafter, the situation in which signals are transmitted and received through channels such as PUCCH, PUSCH, PDCCH, and PDSCH is also expressed in the form of 'transmitting and receiving PUCCH, PUSCH, PDCCH, and PDSCH'.

[0036] For clarity of explanation, the technical idea of ​​this invention is described below mainly with reference to the 3GPP LTE / LTE-A / NR (New RAT) communication system, but the technical features of this invention are not limited to the communication system.

[0037] After researching 4G (4th-Generation) communication technology, 3GPP develops 5G (5th-Generation) communication technology to meet the requirements of the next-generation wireless access technology of the ITU-R. Specifically, 3GPP develops LTE-A pro, which enhances LTE-Advanced technology to meet the requirements of the ITU-R, and NR, a new communication technology separate from 4G communication technology. Both LTE-A pro and NR refer to 5G communication technology, and in the following, 5G communication technology will be explained with NR as the focus, unless a specific communication technology is specifically mentioned.

[0038] The operating scenario in NR defines various operation scenarios by adding considerations for satellites, automobiles, and new verticals to the existing 4G LTE scenario, and in terms of service, it supports the eMBB (Enhanced Mobile Broadband) scenario, the mMTC (Massive Machine Communication) scenario that has high terminal density but is deployed over a wide area and requires low data rate and asynchronous access, and the URLLC (Ultra Reliability and Low Latency) scenario that requires high responsiveness and reliability and can support high-speed mobility.

[0039] To meet these scenarios, NR introduces a wireless communication system that incorporates new waveform and frame structure technologies, low latency technologies, support for ultra-high frequency bands (mmWave), and forward compatibility technologies. In particular, NR systems offer various technological changes in terms of flexibility to ensure forward compatibility. The key technical features of NR are described below with reference to the drawings.

[0040]

[0041] <NR 시스템 일반>

[0042] Figure 1 is a schematic diagram illustrating the structure of an NR system to which the present embodiment can be applied.

[0043] Referring to Fig. 1, the NR system is divided into 5GC (5G Core Network) and NR-RAN parts, and the NG-RAN is composed of gNBs and ng-eNBs that provide user plane (SDAP / PDCP / RLC / MAC / PHY) and control plane (RRC) protocol termination for UE (User Equipment). gNBs or gNBs and ng-eNBs are interconnected via the Xn interface. gNBs and ng-eNBs are each connected to the 5GC via the NG interface. The 5GC can be configured to include an AMF (Access and Mobility Management Function) that is responsible for the control plane such as terminal access and mobility control functions, and an UPF (User Plane Function) that is responsible for the control function for user data. NR includes support for both frequency bands below 6 GHz (FR1, Frequency Range 1) and frequency bands above 6 GHz (FR2, Frequency Range 2).

[0044] gNB refers to a base station that provides NR user plane and control plane protocol termination to terminals, and ng-eNB refers to a base station that provides E-UTRA user plane and control plane protocol termination to terminals. The base station described in this specification should be understood to encompass both gNB and ng-eNB, and may also be used to refer to gNB or ng-eNB separately as needed.

[0045] <NR 웨이브 폼, 뉴머롤러지 및 프레임 구조>

[0046]

[0047] *NR uses the CP-OFDM waveform with a cyclic prefix for downlink transmission, and CP-OFDM or DFT-s-OFDM for uplink transmission. OFDM technology is easily combined with MIMO (Multiple Input Multiple Output) and has the advantage of enabling the use of low-complexity receivers with high frequency efficiency.

[0048] Meanwhile, in NR, the requirements for data rates, latency, and coverage differ across the three scenarios mentioned above. Therefore, it is necessary to efficiently satisfy these requirements across the frequency bands that comprise any NR system. To this end, technologies have been proposed to efficiently multiplex radio resources based on multiple different numerologies.

[0049] Specifically, the NR transmission numerator is determined based on the sub-carrier spacing and the cyclic prefix (CP), and is changed exponentially with the μ value being an exponent value of 2 based on 15 kHz, as shown in Table 1 below.

[0050] μ서브캐리어 간격Cyclic prefixSupported for dataSupported for synch015NormalYesYes130NormalYesYes260Normal, ExtendedYesNo3120NormalYesYes4240NormalNoYes

[0051] As shown in Table 1 above, the numerology of NR can be divided into five types according to the subcarrier spacing. This is different from the fixed subcarrier spacing of LTE, one of the 4G communication technologies, at 15 kHz. Specifically, the subcarrier spacing used for data transmission in NR is 15, 30, 60, and 120 kHz, and the subcarrier spacing used for synchronization signal transmission is 15, 30, 12, and 240 kHz. In addition, the extended CP is applied only to the 60 kHz subcarrier spacing. Meanwhile, the frame structure in NR is defined as a 10 ms frame consisting of 10 subframes with the same length of 1 ms. One frame can be divided into half frames of 5 ms, and each half frame contains 5 subframes. In the case of a 15 kHz subcarrier spacing, one subframe consists of one slot, and each slot consists of 14 OFDM symbols. FIG. 2 is a diagram for explaining the frame structure in an NR system to which the present embodiment can be applied. Referring to FIG. 2, a slot is fixedly composed of 14 OFDM symbols in the case of a normal CP, but the length of the slot in the time domain may vary depending on the subcarrier spacing. For example, in the case of a numerology with a 15 kHz subcarrier spacing, a slot is composed of 1 ms, which is the same length as a subframe. In contrast, in the case of a numerology with a 30 kHz subcarrier spacing, a slot is composed of 14 OFDM symbols, but two slots may be included in one subframe with a length of 0.5 ms. That is, a subframe and a frame are defined with a fixed time length, and a slot is defined by the number of symbols, so the time length may vary depending on the subcarrier spacing.

[0052] Meanwhile, NR defines slots as the basic scheduling unit and also introduces mini-slots (or sub-slots, or non-slot-based scheduling) to reduce transmission delay in the wireless section. Using wider subcarrier spacing reduces transmission delay in the wireless section by shortening the length of each slot inversely. Mini-slots (or sub-slots) are designed to efficiently support URLLC scenarios and allow scheduling in units of 2, 4, or 7 symbols.

[0053] Furthermore, unlike LTE, NR defines uplink and downlink resource allocation at the symbol level within a single slot. To reduce HARQ delay, a slot structure was defined that allows HARQ ACK / NACKs to be transmitted directly within the transmission slot. This slot structure is referred to as a self-contained structure and will be described in detail.

[0054] NR is designed to support a total of 256 slot formats, of which 62 are used in 3GPP Rel-15. It also supports a common frame structure that configures FDD or TDD frames through various combinations of slots. For example, it supports a slot structure in which all symbols in a slot are set to downlink, a slot structure in which all symbols are set to uplink, and a slot structure in which downlink and uplink symbols are combined. NR also supports data transmission being distributed and scheduled across one or more slots. Therefore, a base station can use a slot format indicator (SFI) to inform a UE whether a slot is a downlink slot, an uplink slot, or a flexible slot. The base station can indicate the slot format by indicating an index of a table configured through UE-specific RRC signaling using the SFI, and can also indicate it dynamically through DCI (Downlink Control Information) or statically or semi-statically through RRC.

[0055] <NR 물리 자원 >

[0056] In relation to physical resources in NR, antenna ports, resource grids, resource elements, resource blocks, and bandwidth parts are considered.

[0057] Antenna ports are defined such that the channel through which a symbol on an antenna port is carried can be inferred from the channel through which another symbol on the same antenna port is carried. Two antenna ports are said to be quasi co-located (or quasi co-located) if the large-scale properties of the channel through which a symbol on one antenna port is carried can be inferred from the channel through which a symbol on the other antenna port is carried. Here, the large-scale properties include one or more of delay spread, Doppler spread, frequency shift, average received power, and received timing.

[0058] FIG. 3 is a diagram for explaining a resource grid supported by a wireless access technology to which the present embodiment can be applied.

[0059] Referring to Figure 3, a resource grid may exist for each numeral, as NR supports multiple numerals on the same carrier. Furthermore, resource grids may exist based on antenna ports, subcarrier spacing, and transmission direction.

[0060] A resource block (RB) consists of 12 subcarriers and is defined solely in the frequency domain. Furthermore, a resource element (RE) consists of one OFDM symbol and one subcarrier. Therefore, as shown in Figure 3, the size of a single RB can vary depending on the subcarrier spacing. NR also defines "Point A," which serves as a common reference point for the RB grid, as well as common RBs and virtual RBs.

[0061] FIG. 4 is a diagram for explaining a bandwidth part supported by a wireless access technology to which the present embodiment can be applied.

[0062] Unlike LTE, where the carrier bandwidth is fixed at 20 MHz, NR sets the maximum carrier bandwidth from 50 MHz to 400 MHz for each subcarrier interval. Therefore, it is not assumed that all terminals will use the entire carrier bandwidth. Accordingly, NR allows terminals to designate bandwidth parts (BWPs) within the carrier bandwidth, as illustrated in Figure 4. Furthermore, bandwidth parts are associated with a single numerology, consist of a subset of consecutive common resource blocks, and can be dynamically activated over time. Each terminal is configured with up to four bandwidth parts for both the uplink and downlink, and data is transmitted and received using the bandwidth parts activated at a given time.

[0063] In the case of a paired spectrum, the uplink and downlink bandwidth parts are set independently, and in the case of an unpaired spectrum, the downlink and uplink bandwidth parts are set in pairs so that they can share a center frequency to prevent unnecessary frequency re-tuning between downlink and uplink operations.

[0064] <NR 초기 접속>

[0065] In NR, a terminal performs cell search and random access procedures to connect to a base station and perform communication.

[0066] Cell search is a procedure in which a terminal synchronizes to the cell of a corresponding base station, obtains a physical layer cell ID, and obtains system information using the synchronization signal block (SSB) transmitted by the base station.

[0067] FIG. 5 is a diagram illustrating an example of a synchronization signal block in a wireless access technology to which the present embodiment can be applied.

[0068] Referring to FIG. 5, SSB is composed of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS), each occupying 1 symbol and 127 subcarriers, and a PBCH spanning 3 OFDM symbols and 240 subcarriers.

[0069] The terminal receives SSB by monitoring SSB in the time and frequency domain.

[0070] SSB can be transmitted up to 64 times in 5ms. Multiple SSBs are transmitted in different transmission beams within 5ms, and the terminal performs detection assuming that SSBs are transmitted every 20ms based on a specific beam used for transmission. The number of beams that can be used for SSB transmission within 5ms can increase as the frequency band increases. For example, up to 4 SSB beams can be transmitted below 3GHz, up to 8 in the frequency band between 3GHz and 6GHz, and up to 64 different beams can be used for SSB transmission in the frequency band above 6GHz.

[0071] SSB contains two symbols in one slot, and the starting symbol and number of repetitions within the slot are determined as follows depending on the subcarrier spacing.

[0072] Meanwhile, unlike SS in conventional LTE, SSB is not transmitted at the center frequency of the carrier bandwidth. This means that SSB can be transmitted even in locations other than the center of the system bandwidth, and when supporting wideband operation, multiple SSBs can be transmitted in the frequency domain. Accordingly, the terminal monitors SSB using the synchronization raster, which is a candidate frequency location for monitoring SSB. The carrier raster, which is the center frequency location information of the channel for initial access, and the synchronization raster are newly defined in NR. The synchronization raster has a wider frequency interval than the carrier raster, which can support the terminal's fast SSB search.

[0073] A UE can obtain the MIB through the PBCH of the SSB. The MIB (Master Information Block) includes the minimum information required for the UE to receive the remaining system information (RMSI, Remaining Minimum System Information) broadcast by the network. In addition, the PBCH may include information on the position of the first DM-RS symbol in the time domain, information for the UE to monitor SIB1 (e.g., SIB1 numerology information, information related to SIB1 CORESET, search space information, PDCCH-related parameter information, etc.), offset information between the common resource block and the SSB (the absolute position of the SSB within the carrier is transmitted through SIB1), etc. Here, the SIB1 numerology information is also applied equally to some messages used in the random access procedure for the UE to access the base station after completing the cell search procedure. For example, the numerology information of SIB1 may be applied to at least one of messages 1 to 4 for the random access procedure.

[0074] The aforementioned RMSI may refer to SIB1 (System Information Block 1), and SIB1 is broadcast periodically (e.g., every 160 ms) in the cell. SIB1 contains information necessary for the UE to perform the initial random access procedure and is periodically transmitted via PDSCH. In order for the UE to receive SIB1, it must receive numerology information used for SIB1 transmission and CORESET (Control Resource Set) information used for SIB1 scheduling via PBCH. The UE checks scheduling information for SIB1 using SI-RNTI in CORESET and acquires SIB1 on PDSCH according to the scheduling information. The remaining SIBs, excluding SIB1, may be transmitted periodically or upon request of the UE.

[0075] FIG. 6 is a diagram for explaining a random access procedure in a wireless access technology to which the present embodiment can be applied.

[0076] Referring to FIG. 6, once cell search is complete, the terminal transmits a random access preamble for random access to the base station. The random access preamble is transmitted via the PRACH. Specifically, the random access preamble is transmitted to the base station via the PRACH, which consists of consecutive radio resources in a specific slot that is periodically repeated. Generally, when a terminal initially accesses a cell, a contention-based random access procedure is performed, and when performing random access for beam failure recovery (BFR), a non-contention-based random access procedure is performed.

[0077] The UE receives a random access response to the transmitted random access preamble. The random access response may include a random access preamble identifier (ID), an UL Grant (uplink radio resource), a temporary C-RNTI (Temporary Cell - Radio Network Temporary Identifier), and a TAC (Time Alignment Command). Since one random access response may include random access response information for one or more UEs, the random access preamble identifier may be included to indicate which UE the included UL Grant, temporary C-RNTI, and TAC are valid for. The random access preamble identifier may be an identifier for the random access preamble received by the base station. The TAC may be included as information for the UE to adjust uplink synchronization. The random access response may be indicated by a random access identifier on the PDCCH, i.e., an RA-RNTI (Random Access - Radio Network Temporary Identifier).

[0078] Upon receiving a valid random access response, the terminal processes the information contained in the random access response and performs scheduled transmission to the base station. For example, the terminal applies TAC and stores a temporary C-RNTI. Furthermore, using the UL Grant, the terminal transmits data stored in its buffer or newly generated data to the base station. In this case, information that identifies the terminal must be included.

[0079] Finally, the terminal receives a downlink message for contention resolution.

[0080] <NR CORESET>

[0081] The downlink control channel in NR is transmitted in a CORESET (Control Resource Set) with a length of 1 to 3 symbols, and transmits uplink / downlink scheduling information, SFI (Slot format Index), and TPC (Transmit Power Control) information.

[0082] To ensure system flexibility, NR introduced the CORESET concept. CORESET (Control Resource Set) refers to time-frequency resources for downlink control signals. A terminal can decode control channel candidates using one or more search spaces within the CORESET time-frequency resources. A QCL (Quasi CoLocation) assumption is established for each CORESET, which is used to inform the characteristics of analog beam direction in addition to the delay spread, Doppler spread, Doppler shift, and average delay assumed by the conventional QCL.

[0083] Figure 7 is a drawing for explaining CORESET.

[0084] Referring to Figure 7, a CORESET can exist in various forms within the carrier bandwidth within a single slot, and in the time domain, a CORESET can consist of up to three OFDM symbols. In addition, a CORESET is defined as a multiple of six resource blocks up to the carrier bandwidth in the frequency domain.

[0085] The first CORESET is indicated via the MIB as part of the initial bandwidth part configuration, allowing the terminal to receive additional configuration and system information from the network. After establishing a connection with the base station, the terminal can receive and configure one or more CORESET information via RRC signaling.

[0086] Wider bandwidth operations

[0087] Existing LTE systems supported scalable bandwidth operation for any LTE Component Carrier (CC). That is, depending on the deployment scenario, any LTE operator could configure a single LTE CC with a bandwidth ranging from a minimum of 1.4 MHz to a maximum of 20 MHz, and a normal LTE terminal supported transmission and reception capabilities of 20 MHz bandwidth for a single LTE CC.

[0088] However, in the case of NR, the design is made to support NR terminals with different transmission and reception bandwidth capabilities through a single wideband NR CC, and accordingly, it is required to configure one or more bandwidth parts (BWP, bandwidth part(s)) consisting of segmented bandwidths for any NR CC, and to support flexible wider bandwidth operation through different bandwidth part configurations and activations for each terminal.

[0089] Specifically, in NR, one or more bandwidth parts can be configured through one serving cell configured from the terminal's perspective, and the terminal is defined to activate one downlink bandwidth part (DL bandwidth part) and one uplink bandwidth part (UL bandwidth part) in the serving cell to use them for uplink / downlink data transmission and reception. In addition, when multiple serving cells are configured in the terminal, that is, for the terminal to which CA is applied, it is defined to activate one downlink bandwidth part and / or uplink bandwidth part for each serving cell to use the radio resources of the serving cell to use them for uplink / downlink data transmission and reception.

[0090] Specifically, an initial bandwidth part for an initial access procedure of a terminal in an arbitrary serving cell is defined, one or more UE-specific bandwidth part(s) are configured for each terminal through dedicated RRC signaling, and a default bandwidth part for a fallback operation can also be defined for each terminal.

[0091] However, it can be defined that multiple downlink and / or uplink bandwidth parts can be activated and used simultaneously depending on the capability and bandwidth part(s) configuration of the terminal in any serving cell, but in NR rel-15, it is defined that only one downlink bandwidth part (DL bandwidth part) and one uplink bandwidth part (UL bandwidth part) can be activated and used in any terminal at any time.

[0092] In this specification, the terms frequency, frame, subframe, resource, resource block, region, band, subband, control channel, data channel, synchronization signal, various reference signals, various signals or various messages related to NR (New Radio) may be interpreted in the past or present meaning or in various meanings used in the future.

[0093] In the present disclosure, the random access channel may be referred to as a Physical Random Access Channel (PRACH) or a Random Access Channel (RACH).

[0094]

[0095] The present disclosure proposes a procedure and method for performing random access between a base station and a terminal to support full-duplex communication.

[0096] TDD (Time Division Duplex) is a duplexing method widely used in commercial New Radio (NR) and 5G mobile communication systems. In TDD, time-slot radio resources are divided into downlink and uplink slots. Typically, downlink slots are distributed at a higher rate than uplink slots, depending on the distribution ratio of uplink to downlink traffic. However, this limitation on uplink slots negatively impacts coverage and latency. Full-duplex communication can be applied as a technology to address these issues.

[0097] Full-duplex communication is a technology that performs DL transmission and UL reception simultaneously on the same radio resources, specifically at the gNB, or base station. Simultaneous DL reception and UL transmission can also be performed at the terminal side. In other words, both the base station and the terminal can support full duplex. However, unlike the base station, which is structurally easy to cancel self-interference, the DL reception performance of the terminal is easily affected by self-interference of the UL transmission signal. Therefore, it is generally considered that the base station operates in full-duplex communication, and the terminal operates in half-duplex communication. Additionally, to reduce the influence of self-interference at the base station, a subband non-overlapping full-duplex (subband non-overlapping full-duplex, also referred to as SBFD or subband full-duplex in this disclosure) method can be primarily considered, in which DL transmission and UL reception are performed simultaneously, but the DL / UL are transmitted and received by distinguishing frequency resources rather than using the same resources.

[0098] FIG. 8 is a diagram illustrating an example in which an uplink subband is set in an arbitrary downlink slot according to one embodiment. FIG. 9 is a diagram illustrating another example in which an uplink subband is set in an arbitrary downlink slot according to one embodiment.

[0099] That is, FIGS. 8 and 9 illustrate examples in which DL slots and UL slots are configured in a ratio of 4:1 in an arbitrary NR frequency band. However, some symbols of the last DL slot may be special slots including flexible symbols for DL / UL transition. In this way, when a TDD (Time Division Duplex) configuration is made, an uplink subband (UL subband) may be set to support UL transmission of a terminal in some (or all) of the DL slots. When a UL subband is set in an arbitrary DL slot, the UL subband may be set at the center of the frequency band, as shown in FIG. 8, or at the edge of the frequency band, as shown in FIG. 9. In this case, a guard band may be set between the UL subband and the downlink subband (DL subband) in the slot.

[0100] In addition, for frequency resources other than the UL subband and guard band, they can be utilized as DL subbands for DL ​​transmission and reception according to the existing slot / symbol configuration information. That is, as in FIG. 8, if the UL subband is configured around the center of the frequency band, two guard bands, one each above and below the UL subband, can be configured, and then similarly, two DL subbands, one each above and below the UL subband, can be configured. Alternatively, as in FIG. 9, if the UL subband is configured at the edge of the frequency band, one guard band and one DL subband can be configured following the UL subband.

[0101] The UL-DL slot configuration defined in NR is defined to be done on a cell-by-cell basis through cell-specific RRC signaling. That is, a pattern of DL symbols, UL symbols, and flexible symbols for a certain period is set through the RRC message 'tdd-UL-DL-ConfigurationCommon' for the corresponding UL-DL slot configuration. Additionally, through the UE-specific RRC signaling 'tdd-UL-DL-ConfigurationDedicated', only the flexible symbols set through the 'tdd-UL-DL-ConfigurationCommon' can be reallocated to UL symbols, DL symbols, or flexible symbols for each UE. Alternatively, a method for indicating a dynamic slot format through a UE-group common PDCCH is also defined. For this purpose, NR also supports a dynamic slot format indication method through DCI format 2_0.

[0102] According to the slot configuration method described above, any one symbol can be set or indicated as one of DL, UL, or Flexible. FIG. 8 is an example in which an arbitrary slot format is set to DDDSU through the existing slot configuration. D refers to a downlink slot, meaning that all OFDM symbols constituting the slot are set to DL. U refers to an uplink slot, meaning that all OFDM symbols constituting the slot are set to UL. S refers to a special slot, meaning that a slot includes a flexible symbol for DL / UL transition. Typically, in the case of a normal CP, the special slot can be configured with 12 DL symbols and 2 flexible symbols out of a total of 14 symbols. Alternatively, it can be configured with 10 DL symbols, 2 flexible symbols, and 2 UL symbols. That is, within any one TDD carrier, one symbol is configured or indicated as only one of DL, UL, or flexible.

[0103] However, as shown in FIGS. 8 and 9, if a UL subband is configured in any DL slot, DL transmission or UL transmission can occur simultaneously for each frequency resource in the symbol. In this way, a DL slot or symbol including a UL subband, or a UL slot or symbol including a DL subband, is referred to as an SBFD (subband full duplex) slot or SBFD symbol in the present disclosure.

[0104] In addition, in the present disclosure, a slot composed only of the SBFD symbols is referred to as an SBFD slot, and a slot composed only of symbols according to existing symbol settings (i.e., a slot composed only of symbols that do not include a UL subband, a DL subband, and a guardband) is referred to as a non-SBFD slot. Alternatively, a slot including at least one SBFD symbol may be referred to as an SBFD slot. As mentioned above, this is for convenience of explanation and is not limited to the terminology.

[0105]

[0106] Below, a method for transmitting and receiving downlink data in a wireless mobile communication system will be specifically described with reference to related drawings.

[0107] FIG. 10 is a diagram illustrating a procedure (1000) for a terminal to receive downlink data according to one embodiment.

[0108] Referring to FIG. 10, a terminal can receive random access channel (RACH) configuration information (S1010).

[0109] In this disclosure, we assume that a terminal and a base station support full-duplex communication based on subband non-overlapping. In this case, certain frequency resources within the same symbol in a TDD carrier can be used for downlink transmission, while other frequency resources can be used for uplink reception. That is, within a TDD carrier, some frequency resources in any downlink symbol can be configured to be utilized for uplink transmission by a terminal, or as flexible symbols for downlink / uplink transitions.

[0110] A terminal may configure a downlink subband in an uplink slot, or receive information about a time domain and a frequency domain for configuring an uplink subband in a downlink slot. According to an example, the SBFD configuration information may include configuration information about at least one uplink subband and at least one downlink subband. In addition, the SBFD configuration information may include configuration information about an SBFD symbol in which an uplink subband and a downlink subband are configured in the frequency domain. Alternatively, the SBFD configuration information may include information about a frequency domain in which a guard band is configured and information about a time domain. Here, the frequency resource information may include resource block allocation information, and the time resource information may include SBFD symbol allocation information.

[0111] In addition, for configuring SBFD subbands, time resource information for uplink subbands can be set based on reference subcarrier spacing (SCS) information and pattern setting information. In this case, the time resource information can be set based on the reference subcarrier spacing (SCS) included in the TDD configuration information. That is, the reference subcarrier spacing (SCS) setting included in the TDD configuration information can be used as a reference SCS for setting time resources for configuring uplink subbands.

[0112] Additionally, time resource information can be set based on the number of TDD patterns and the period of the patterns included in the TDD configuration information. That is, the settings for Pattern 1 and Pattern 2 included in the TDD configuration information can be used as pattern setting information for setting time resources for configuring an uplink subband.

[0113] In this case, the SBFD symbol allocation information may be set to consecutive SBFD symbols within the cycle of a TDD pattern set to one or two. Each pattern setting information may include cycle setting information, offset information, and duration information of the corresponding pattern. At this time, the duration information may be set to the number of consecutive SBFD symbols from the offset, or may be set to a combination of the number of consecutive SBFD slots and the number of consecutive SBFD symbols. Alternatively, according to an example, the offset may be set to an end point instead of a start point. That is, offset information corresponding to the end point and duration information from the end point may be set.

[0114] For configuring SBFD subbands, frequency resource configuration information for uplink subbands may be configured in units of common resource blocks (CRBs). In this case, frequency resource configuration for uplink subbands may be accompanied by guardband configuration or downlink subband configuration within the same symbol / slot. That is, frequency resource configuration information for uplink subbands may include at least one of guardbands accompanying an SBFD slot or SBFD symbol in which the uplink subband is configured, or frequency resource configuration information for downlink subbands. In this case, time resource configuration information for the guardband or downlink subbands may be configured according to the time resource configuration information of the uplink subband.

[0115] For example, for configuring SBFD subbands, frequency resource information for an uplink subband may include configuration information for one uplink subband and one or two guard bands based on a CRB. In this case, if the uplink subband is located in the center of the frequency band, two guard bands may be configured above and below the uplink subband. Alternatively, if the uplink subband is located at the upper boundary of the frequency band, one guard band may be configured below the uplink subband. Alternatively, if the uplink subband is located at the lower boundary of the frequency band, one guard band may be configured above the uplink subband. Accordingly, configuration information for one or two guard bands may be included in the frequency resource information. In this case, a downlink subband may be configured with a guard band in between, and the downlink subband may be inferred from the frequency resource information for the uplink subband and the guard band.

[0116] In another example, for configuring SBFD subbands, frequency resource information for an uplink subband may include configuration information for one uplink subband and one or two downlink subbands based on a CRB. In this case, if the uplink subband is located in the center of the frequency band, two downlink subbands may be configured above and below the uplink subband. Alternatively, if the uplink subband is located at the upper boundary of the frequency band, one downlink subband may be configured below the uplink subband. Alternatively, if the uplink subband is located at the lower boundary of the frequency band, one downlink subband may be configured above the uplink subband. Accordingly, configuration information for one or two downlink subbands may be included in the frequency resource information. In this case, a guard band may be configured between the uplink subband and the downlink subband, and the guard band may be inferred from the frequency resource information for the uplink subband and the downlink subband.

[0117] For example, SBFD configuration information can be received via cell-specific upper layer signaling. That is, the terminal can receive SBFD subband configuration information from the base station via cell-specific RRC signaling. The terminal can receive the TDD configuration information and SBFD subband configuration information to configure a format for each slot.

[0118] A terminal can receive random access channel (RACH) configuration information from a base station through system information. The RACH configuration information can include various information fields for performing a random access procedure. For example, the RACH configuration information can include rach-ConfigGeneric configuration information and configuration values ​​for information fields such as totalNumberofRA-Preambles, SSB-PerRACH-OccasionAndCB-PreamblesPerSSB, groupBconfigured, ra-ContentionResolutionTimer, rsrp-ThresholdSSB, prach-RootSequenceIndex, msg1-SubcarrierSpacing, restrictedSetConfig, and msg3-transormPrecoder.

[0119] Referring again to FIG. 10, the terminal may determine one of a plurality of random access channel occasions (RACH occasions; ROs) configured based on RACH configuration information (S1020) and transmit a random access preamble in the determined RO (S1030).

[0120] When a PDCCH order is received or a random access procedure is performed due to a Beam Failure indication, etc., the terminal can transmit a random access (RA) preamble using a RACH occasion of a PRACH (Physical Random Access Channel) slot configured by RACH configuration information. In this case, the PRACH slot and RACH occasion for transmitting the random access preamble can be configured only through slots and symbols set to uplink through the aforementioned 'tdd-UL-DL-ConfigurationCommon'.

[0121] However, if full-duplex communication is supported, the terminal may also transmit a random access preamble through an uplink subband of an SBFD symbol. To this end, the RACH configuration information may include first RACH configuration information for configuring at least one first RO and second RACH configuration information for configuring at least one second RO for subband full duplex (SBFD). Here, the first RACH configuration information may refer to RACH-ConfigCommon, which is conventionally used RACH configuration information, and the second RACH configuration information may refer to RACH-configSBFD, which is newly introduced RACH configuration information for SBFD. Accordingly, at least one first RO refers to a RACH okayness configured according to conventional RACH configuration information, and at least one second RO refers to a RACH okayness configured according to RACH configuration information for SBFD.

[0122] For example, the second RACH configuration information may include all of the aforementioned rach-ConfigGeneric configuration information and configuration values ​​for information areas such as totalNumberofRA-Preambles, SSB-PerRACH-OccasionAndCB-PreamblesPerSSB, groupBconfigured, ra-ContentionResolutionTimer, rsrp-ThresholdSSB, prach-RootSequenceIndex, msg1-SubcarrierSpacing, restrictedSetConfig, and msg3-transormPrecoder. Alternatively, the second RACH configuration information may include configuration values ​​for only some of the information areas. In this case, information areas not included in the second RACH configuration information may be configured to follow the configuration values ​​of the first RACH configuration information.

[0123] When the terminal receives the second RACH configuration information, it can set the RACH OK and the corresponding PRACH resources in the symbol set to downlink (DL) or flexible by 'tdd-UL-DL-ConfigurationCommon'. In this case, according to an example, the PRACH slot or RACH OK (second RO) by the second RACH configuration information can be limited to the DL or flexible symbol by 'tdd-UL-DL-ConfigurationCommon'.

[0124] Alternatively, the PRACH slot or RACH OK signal (second RO) by the second RACH configuration information may be limited to an SBFD symbol in which an uplink subband is configured among the DL or flexible symbols by 'tdd-UL-DL-ConfigurationCommon'. That is, at least one second RO, if configured through an SBFD symbol, may be used to determine an RO in which a random access preamble is transmitted. Specifically, the second ROs configured according to the second RACH configuration information may be used as valid RACH OK signals only when they are configured in an SBFD symbol among the symbols configured in the terminal. Accordingly, the terminal may not transmit a random access preamble in the second RO configured in a non-SBFD symbol.

[0125] For example, a terminal may be instructed by a base station to transmit a random access preamble of the terminal according to a PDCCH order through DCI format 1_0. DCI format 1_0 for PDCCH order may include random access preamble index indication information, UL / SUL (Uplink / Supplementary Uplink) indicators, SS / PBCH index indication information, PRACH mask index information, and reserved bits.

[0126] The terminal may preferentially select one type of RO from among at least one first RO and at least one second RO. That is, one RO for transmitting a random access preamble may be determined from at least one RO determined from among at least one first RO and at least one second RO.

[0127] In this case, at least one of the first RO and the second RO may be determined based on an instruction transmitted from the base station. The instruction received from the base station may include downlink control information including a PDCCH order. For example, DCI format 1_0 including the PDCCH order may include information indicating whether to determine a RACH OK based on the first RACH configuration information or whether to determine a RACH OK based on the second RACH configuration information.

[0128] The terminal may determine either the first RO or the second RO based on information included in the downlink control information. If the terminal determines the second RO, it may determine at least one of the second ROs to transmit the random access preamble. The terminal may transmit the random access preamble to the base station from the determined RO.

[0129] Accordingly, a method and device for performing a random access procedure in an environment where full-duplex communication is applied can be provided.

[0130] FIG. 11 is a diagram illustrating a procedure (1100) for a base station to perform a random access procedure according to one embodiment. The description given above in FIG. 10 may be omitted to avoid redundant explanation. In this case, the omitted content may be substantially equally applied to the base station, as long as it does not conflict with the technical spirit of the invention.

[0131] Referring to FIG. 11, the base station can transmit random access channel (RACH) configuration information (S1110).

[0132] A base station can transmit random access channel (RACH) configuration information to a terminal through system information. The RACH configuration information can include various information fields for performing a random access procedure. For example, the RACH configuration information can include rach-ConfigGeneric configuration information and configuration values ​​for information fields such as totalNumberofRA-Preambles, SSB-PerRACH-OccasionAndCB-PreamblesPerSSB, groupBconfigured, ra-ContentionResolutionTimer, rsrp-ThresholdSSB, prach-RootSequenceIndex, msg1-SubcarrierSpacing, restrictedSetConfig, and msg3-transormPrecoder.

[0133] Referring again to FIG. 11, the base station can receive a random access preamble in one of a plurality of random access channel occasions (RACH occasions; ROs) configured based on RACH configuration information (S1120).

[0134] When a PDCCH order is received or a random access procedure is performed due to a Beam Failure indication, etc., the base station can receive a random access (RA) preamble using a RACH occasion of a PRACH (Physical Random Access Channel) slot configured by RACH configuration information. In this case, the PRACH slot and RACH occasion for transmitting the random access preamble can be configured only through slots and symbols set to uplink through the aforementioned 'tdd-UL-DL-ConfigurationCommon'.

[0135] However, if full-duplex communication is supported, the base station can also receive the random access preamble through the uplink subband of the SBFD symbol. To this end, the RACH configuration information may include first RACH configuration information for configuring at least one first RO and second RACH configuration information for configuring at least one second RO for subband full duplex (SBFD). Here, the first RACH configuration information may mean RACH-ConfigCommon, which is conventionally used RACH configuration information, and the second RACH configuration information may mean RACH-configSBFD, which is newly introduced RACH configuration information for SBFD. Accordingly, at least one first RO means a RACH okay configured according to conventional RACH configuration information, and at least one second RO means a RACH okay configured according to RACH configuration information for SBFD.

[0136] For example, the second RACH configuration information may include all of the aforementioned rach-ConfigGeneric configuration information and configuration values ​​for information areas such as totalNumberofRA-Preambles, SSB-PerRACH-OccasionAndCB-PreamblesPerSSB, groupBconfigured, ra-ContentionResolutionTimer, rsrp-ThresholdSSB, prach-RootSequenceIndex, msg1-SubcarrierSpacing, restrictedSetConfig, and msg3-transormPrecoder. Alternatively, the second RACH configuration information may include configuration values ​​for only some of the information areas. In this case, information areas not included in the second RACH configuration information may be configured to follow the configuration values ​​of the first RACH configuration information.

[0137] When the terminal receives the second RACH configuration information, it can set the RACH OK and the corresponding PRACH resources in the symbol set to downlink (DL) or flexible by 'tdd-UL-DL-ConfigurationCommon'. In this case, according to an example, the PRACH slot or RACH OK (second RO) by the second RACH configuration information can be limited to the DL or flexible symbol by 'tdd-UL-DL-ConfigurationCommon'.

[0138] Alternatively, the PRACH slot or RACH OK (second RO) by the second RACH configuration information may be limited to an SBFD symbol in which an uplink subband is configured among the DL or flexible symbols by 'tdd-UL-DL-ConfigurationCommon'. That is, at least one second RO, if configured through an SBFD symbol, may be used to determine an RO in which a random access preamble is transmitted. Specifically, the second ROs configured according to the second RACH configuration information may be used as valid RACH OK only when they are configured in an SBFD symbol among the symbols configured in the terminal. Therefore, the base station may not receive a random access preamble in a second RO configured in a non-SBFD symbol.

[0139] For example, a base station can instruct a terminal to transmit a random access preamble to the terminal according to a PDCCH order through DCI format 1_0. DCI format 1_0 for PDCCH order can include random access preamble index indication information, UL / SUL (Uplink / Supplementary Uplink) indicators, SS / PBCH index indication information, PRACH mask index information, and reserved bits.

[0140] The terminal may preferentially select one type of RO from among at least one first RO and at least one second RO. That is, one RO for transmitting a random access preamble may be determined from at least one RO determined from among at least one first RO and at least one second RO.

[0141] In this case, at least one of the first RO and the second RO may be determined based on an instruction transmitted from the base station. The instruction received from the base station may include downlink control information including a PDCCH order. For example, DCI format 1_0 including the PDCCH order may include information indicating whether to determine a RACH OK based on the first RACH configuration information or whether to determine a RACH OK based on the second RACH configuration information.

[0142] The terminal may determine either the first RO or the second RO based on information included in the downlink control information. If the terminal determines the second RO, it may determine at least one of the second ROs to transmit the random access preamble. The base station may receive the random access preamble from the terminal in the determined RO.

[0143] Accordingly, a method and device for performing a random access procedure in an environment where full-duplex communication is applied can be provided.

[0144]

[0145] Hereinafter, each embodiment related to a method for performing a random access procedure in a wireless mobile communication system will be specifically described with reference to related drawings.

[0146] According to the random access execution procedure of the existing terminal, the terminal receives RACH-ConfigCommon configuration information for random access from the base station through system information, and receives PRACH configuration information for random access preamble transmission. Accordingly, when the random access procedure is performed by the terminal by receiving a PDCCH command (order), a BF (Beam Failure) indication from the MAC (Medium Access Control) sublayer, the RRC (Radio Resource Control) sublayer, or the physical layer (PHY), the terminal can transmit a random access preamble using the RACH occasion of the PRACH slot configured by the RACH-configCommon configuration information. However, the PRACH slot and RACH occasion by the RACH-ConfigCommon can be configured only through the slot and symbol configured as UL through the 'tdd-UL-DL-ConfigurationCommon'.

[0147] In the present disclosure, a method is proposed in which a base station allocates PRACH resources that enable transmission of a random access preamble from a terminal through a UL subband of the SBFD symbol, and the terminal transmits a random access preamble through the SBFD symbol based on the PRACH resources.

[0148] According to one example of the present disclosure, a base station may configure separate RACH-config information to support random access preamble transmission of a terminal through an UL subband of the SBFD symbol and transmit the same to the terminal. For example, the base station transmits RACH-configSBFD information to the terminal. The RACH-configSBFD includes PRACH configuration information for an SBFD symbol for which UL subband configuration is performed. The PRACH configuration information may include all of the rach-ConfigGeneric configuration information and configuration values ​​for information areas such as totalNumberofRA-Preambles, SSB-PerRACH-OccasionAndCB-PreamblesPerSSB, groupBconfigured, ra-ContentionResolutionTimer, rsrp-ThresholdSSB, prach-RootSequenceIndex, msg1-SubcarrierSpacing, restrictedSetConfig, and msg3-transormPrecoder, or may include configuration values ​​for only some of the information areas among the information areas. At this time, if RACH-configSBFD includes only setting values ​​for some of the information areas among the information areas, the information areas not included in RACH-configSBFD may follow the setting values ​​through the RACH-ConfigCommon.

[0149] At this time, the SSB-PerRACH-OccasionAndCB-PreamblesPerSSB configuration information for RACH occasion configuration associated with any SSB can be configured by the base station and interpreted by the terminal according to the following embodiment.

[0150] As a first embodiment, the SSBPerRACH-OccasionAndCB-PreamblesPerSSB included in the RACH-ConfigSBFD may be set by identically referencing the SSB (Synchronization Signal Block) transmission and the SSB index thereof referenced by the SSBPerRACH-OccasionAndCB-PreamblesPerSSB setting included in the RACH-ConfigCommon. For example, the SSBPerRACH-OccasionAndCB-PreamblesPerSSB setting included in the RACH-ConfigSBFD may be set by referring to the CD (Cell Defining)-SSB in which PBCH transmission including PDCCH configuration information for receiving at least SIB1 (System Information Block 1) including RACH-ConfigCommon is performed, and may be interpreted by the terminal.

[0151] As another embodiment, SSBPerRACH-OccasionAndCB-PreamblesPerSSB included in RACH-ConfigSBFD can be configured to reference a separate SSB or CSI-RS (channel state information-reference signal) transmitted through a downlink subband (DL subband) of an SBFD symbol. For example, the base station can configure a separate SSB transmission through the DL subband of the SBFD symbol for the purpose of beam management or channel measurement in the SBFD symbol. The configuration information can include SSB transmission period configuration information, SSB transmission slot and symbol allocation information within the SSB transmission period (e.g., slot offset or symbol offset information), information on the number of SSBs, SSB frequency allocation information (e.g., RB offset information), etc., and can be configured through UE-specific or cell-specific RRC signaling. In this way, when a separate SSB transmission setting is made for the SBFD symbol, the terminal can interpret SSBPerRACH-OccasionAndCB-PreamblesPerSSB included in the RACH-ConfigSBFD by referring to the SSB transmission and SSB index for the corresponding SBFD symbol.

[0152] Alternatively, the base station may configure any CSI-resourceConfig_SBFD for the purpose of beam management or channel measurement in an SBFD symbol, and the RACH-ConfigSBFD may include CSI-RSPerRACH-OccasionAndCB-PreamblesPerCSI-RS instead of SSBPerRACH-OccasionAndCB-PreamblesPerSSB. Accordingly, the base station may configure associated RACH occasion configuration information for each CSI-RS through the CSI-RSPerRACH-OccasionAndCB-PreamblesPerCSI-RS with reference to the CSI-resourceConfig_SBFD for the corresponding SBFD symbol. In this case, when one or more CSI-resourceConfig_SBFD configurations are performed for an SBFD symbol, the RACH-ConfigSBFD information may include CSI-resource ID information that is a target of CSI-RSPerRACH-OccasionAndCB-PreamblesPerCSI-RS configuration.

[0153] The above RACH-ConfigSBFD can be transmitted to the terminal via UE-specific or cell-specific RRC signaling.

[0154] When the terminal receives the RACH-ConfigSBFD, it configures a RACH occasion and corresponding PRACH resources in a symbol set to DL or flexible by 'tdd-UL-DL-ConfigurationCommon'. However, in this case, the PRACH slot or RACH occasion by RACH-ConfigSBFD may be limited to a DL or flexible symbol by 'tdd-UL-DL-ConfigurationCommon'. Alternatively, the PRACH slot or RACH occasion by RACH-ConfigSBFD may be limited to an SBFD symbol in which a UL subband is configured among the DL or flexible symbols by 'tdd-UL-DL-ConfigurationCommon'.

[0155] Below, a method for transmitting a random access preamble by PDCCH order of a terminal according to the above RACH-ConfigSBFD setting is proposed.

[0156] Through DCI format 1_0, a base station can instruct a random access preamble transmission of a terminal by a PDCCH order for an arbitrary terminal. DCI format 1_0 for the PDCCH order includes random access preamble index indication information, UL / SUL (Uplink / Supplementary Uplink) indicators, SS / PBCH index indication information, PRACH mask index information, and reserved bits. The terminal transmits the random access preamble indicated by the preamble index indication information through the PRACH of the RACH occasion indicated by the SS / PBCH index indication information and the PRACH Mask index information after a minimum time gap from the last symbol in which the PDCCH order is received from the base station. The minimum time gap between the reception of the PDCCH order and the transmission of the random access preamble is determined by the PUSCH preparation time, the BWP switching delay, and the MAC layer delay for PRACH initialization. At this time, in determining a RACH occasion and PRACH resource by the SS / PBCH index indication information and PRACH Mask index information, the terminal may determine a RACH occasion for transmitting a random access preamble according to the SS / PBCH index indication information and PRACH Mask index information based on a RACH occasion configured through an SBFD symbol by the RACH-configSBFD.Alternatively, the terminal may determine a RACH occasion for transmitting a random access preamble based on the SS / PBCH index indication information and PRACH Mask index information based on the RACH occasion configured through the UL symbol by the RACH-configCommon as before. Accordingly, the base station may implicitly or explicitly indicate whether the RACH occasion determination of the terminal based on the reception of the PDCCH order will be based on the RACH-configSBFD or RACH-configCommon.

[0157] As an example of an implicit decision method, it may be determined based on the type of symbol through which the DCI format 1_0 including the PDCCH order is transmitted. That is, if the DCI format 1_0 including the PDCCH order is transmitted through an SBFD symbol, the UE may determine a RACH occasion for transmitting a random access preamble according to the PDCCH order based on the RACH-configSBFD, and conversely, if the DCI format 1_0 including the PDCCH order is transmitted through a non-SBFD symbol, the UE may determine a RACH occasion for transmitting a random access preamble according to the PDCCH order based on the existing RACH-configCommon. Alternatively, the interpretation of the PDCCH order may be determined based on the type of the search space through which the DCI format 1_0 including the PDCCH order is transmitted or the CRC (Cyclic redundancy check) scrambling ID of the PDCCH.

[0158] As an explicit decision method, DCI format 1_0 including the PDCCH order may include indication information therefor (i.e., information indicating whether to determine a RACH occasion based on RACH-configSBFD or based on RACH-configCommon).

[0159] That is, the base station can implicitly or explicitly instruct the terminal as to whether the random access preamble transmission according to the above PDCCH order is to be performed through a RACH occasion of a non-SBFD symbol by RACH-configCommon or through a RACH occasion of an SBFD symbol by RACH-configSBFD.

[0160] Alternatively, the terminal may transmit the indicated random access preamble through the first valid RACH occasion after the minimum time gap after receiving the PDCCH order, regardless of the symbol type / type of the RACH occasion (i.e., SBFD symbol or non-SBFD symbol). That is, the terminal may transmit the indicated preamble through the first RACH occasion after the minimum time gap among the RACH occasion in the UL symbol derived based on the RACH-configCommon configuration and the RACH occasion in the SBFD symbol derived based on the RACH-configSBFD configuration, respectively, according to the SS / PBCH index indication information and PRACH Mask index information of the PDCCH order.

[0161] Additionally, the PDCCH order interpretation method of the above terminal and the random access preamble transmission method according to the method can be set by the base station and transmitted to the terminal through RRC signaling.

[0162] With respect to the above-described embodiments, each embodiment is included in the scope of the invention according to the present disclosure not only in an independent case but also in all cases in which the embodiments are combined.

[0163]

[0164] Hereinafter, the configuration of a terminal and a base station capable of performing some or all of the embodiments described with reference to FIGS. 1 to 11 will be described with reference to the drawings. The above description may be omitted to avoid redundant description, and in this case, the omitted content may be substantially equally applied to the following description, as long as it does not contradict the technical spirit of the invention.

[0165] Fig. 12 is a drawing showing the configuration of a terminal (1200) according to another embodiment.

[0166] Referring to FIG. 12, a terminal (1200) according to another embodiment includes a transmitter (1220), a receiver (1230), and a control unit (1210) that controls the operations of the transmitter and receiver.

[0167] The control unit (1210) controls the overall operation of the terminal (1200) according to the method for performing a random access procedure in a wireless mobile communication system required to perform the present invention described above.

[0168] The control unit (1210) can receive random access channel (RACH) configuration information from the base station through system information. The RACH configuration information can include various information fields for performing a random access procedure.

[0169] The control unit (1210) can determine one of a plurality of random access channel occasions (RACH occasions; ROs) configured based on RACH configuration information, and transmit a random access preamble in the determined RO. When a PDCCH order is received or a random access procedure is performed due to a beam failure indication, etc., the terminal can transmit a random access (RA) preamble using a RACH occasion of a PRACH (Physical Random Access Channel) slot configured by the RACH configuration information. In this case, the PRACH slot and RACH occasion for transmitting the random access preamble can be configured only through slots and symbols set to uplink through the aforementioned 'tdd-UL-DL-ConfigurationCommon'.

[0170] However, when full-duplex communication is supported, the control unit (1210) may also transmit a random access preamble through an uplink subband of an SBFD symbol. To this end, the RACH configuration information may include first RACH configuration information for configuring at least one first RO and second RACH configuration information for configuring at least one second RO for subband full duplex (SBFD). Here, the first RACH configuration information may refer to RACH-ConfigCommon, which is conventionally used RACH configuration information, and the second RACH configuration information may refer to RACH-configSBFD, which is newly introduced RACH configuration information for SBFD. Accordingly, at least one first RO refers to a RACH okay configured according to conventional RACH configuration information, and at least one second RO refers to a RACH okay configured according to RACH configuration information for SBFD.

[0171] For example, the second RACH configuration information may include all configuration values ​​for various information areas for performing the random access procedure configured in the first RACH configuration information. Alternatively, the second RACH configuration information may include configuration values ​​for only some of the information areas. In this case, information areas not included in the second RACH configuration information may be configured to follow the configuration values ​​of the first RACH configuration information.

[0172] When the control unit (1210) receives the second RACH configuration information, it can set the RACH occupancy and the corresponding PRACH resources in the symbol set to downlink (DL) or flexible by 'tdd-UL-DL-ConfigurationCommon'. In this case, according to an example, the PRACH slot or RACH occupancy (second RO) by the second RACH configuration information can be limited to the DL or flexible symbol by 'tdd-UL-DL-ConfigurationCommon'.

[0173] Alternatively, the PRACH slot or RACH OK (second RO) by the second RACH configuration information may be limited to an SBFD symbol in which an uplink subband is configured among the DL or flexible symbols by 'tdd-UL-DL-ConfigurationCommon'. That is, at least one second RO, if configured through an SBFD symbol, may be used to determine an RO in which a random access preamble is transmitted. Specifically, the second ROs configured according to the second RACH configuration information may be used as valid RACH OK only when they are configured in an SBFD symbol among the symbols configured in the terminal. Therefore, the control unit (1210) may not transmit a random access preamble in the second RO configured in a non-SBFD symbol.

[0174] For example, the control unit (1210) may be instructed by the base station to transmit a random access preamble of a terminal according to a PDCCH order through DCI format 1_0. DCI format 1_0 for the PDCCH order may include random access preamble index indication information, UL / SUL (Uplink / Supplementary Uplink) indicator, SS / PBCH index indication information, PRACH mask index information, and reserved bits.

[0175] The control unit (1210) can preferentially select one type of RO from among at least one first RO and at least one second RO. That is, one RO for transmitting a random access preamble can be determined from at least one RO determined from among at least one first RO and at least one second RO.

[0176] In this case, at least one of the first RO and the second RO may be determined based on an instruction transmitted from the base station. The instruction received from the base station may include downlink control information including a PDCCH order. For example, DCI format 1_0 including the PDCCH order may include information indicating whether to determine a RACH OK based on the first RACH configuration information or whether to determine a RACH OK based on the second RACH configuration information.

[0177] The control unit (1210) may determine either the first RO or the second RO based on information included in the downlink control information. If the control unit (1210) determines the second RO, it may determine one RO among at least one second RO to transmit the random access preamble. The terminal may transmit the random access preamble to the base station from the determined RO.

[0178] Accordingly, a method and device for performing a random access procedure in an environment where full-duplex communication is applied can be provided.

[0179] Accordingly, a method and device for performing a random access procedure in an environment where full-duplex communication is applied can be provided.

[0180] Fig. 13 is a drawing showing the configuration of a base station (1300) according to another embodiment.

[0181] Referring to FIG. 13, a base station (1300) according to another embodiment includes a transmitter (1320), a receiver (1330), and a control unit (1310) that controls the operations of the transmitter and receiver.

[0182] The control unit (1310) controls the overall operation of the base station (1300) according to the method for performing a random access procedure in a wireless mobile communication system required to perform the aforementioned present invention. The transmitter (1320) transmits downlink control information, data, and messages to the terminal through the corresponding channel. The receiver (1330) receives uplink control information, data, and messages from the terminal through the corresponding channel.

[0183] The control unit (1310) may transmit random access channel (RACH) configuration information. The control unit (1310) may transmit random access channel (RACH) configuration information to the terminal via system information. The RACH configuration information may include various information fields for performing a random access procedure.

[0184] The control unit (1310) can receive a random access preamble in one of a plurality of random access channel occasions (RACH occasions; ROs) configured based on RACH configuration information. When a PDCCH order is received or a random access procedure is performed due to a beam failure indication, etc., the control unit (1310) can receive a random access (RA) preamble using a RACH occasion of a PRACH (Physical Random Access Channel) slot configured by the RACH configuration information. In this case, the PRACH slot and RACH occasion for transmitting the random access preamble can be configured only through slots and symbols set to uplink through the aforementioned 'tdd-UL-DL-ConfigurationCommon'.

[0185] However, when full-duplex communication is supported, the control unit (1310) may also receive a random access preamble through an uplink subband of an SBFD symbol. To this end, the RACH configuration information may include first RACH configuration information for configuring at least one first RO and second RACH configuration information for configuring at least one second RO for subband full duplex (SBFD). Here, the first RACH configuration information may refer to RACH-ConfigCommon, which is conventionally used RACH configuration information, and the second RACH configuration information may refer to RACH-configSBFD, which is newly introduced RACH configuration information for SBFD. Accordingly, at least one first RO refers to a RACH okay configured according to conventional RACH configuration information, and at least one second RO refers to a RACH okay configured according to RACH configuration information for SBFD.

[0186] For example, the second RACH configuration information may include all configuration values ​​for various information areas for performing the random access procedure configured in the first RACH configuration information. Alternatively, the second RACH configuration information may include configuration values ​​for only some of the information areas. In this case, information areas not included in the second RACH configuration information may be configured to follow the configuration values ​​of the first RACH configuration information.

[0187] When the terminal receives the second RACH configuration information, it can set the RACH OK and the corresponding PRACH resources in the symbol set to downlink (DL) or flexible by 'tdd-UL-DL-ConfigurationCommon'. In this case, according to an example, the PRACH slot or RACH OK (second RO) by the second RACH configuration information can be limited to the DL or flexible symbol by 'tdd-UL-DL-ConfigurationCommon'.

[0188] Alternatively, the PRACH slot or RACH OK (second RO) by the second RACH configuration information may be limited to an SBFD symbol in which an uplink subband is configured among the DL or flexible symbols by 'tdd-UL-DL-ConfigurationCommon'. That is, at least one second RO, if configured through an SBFD symbol, may be used to determine an RO in which a random access preamble is transmitted. Specifically, the second ROs configured according to the second RACH configuration information may be used as valid RACH OK only when they are configured in an SBFD symbol among the symbols configured in the terminal. Therefore, the control unit (1310) may not receive a random access preamble in a second RO configured in a non-SBFD symbol.

[0189] For example, the control unit (1310) may instruct the terminal to transmit a random access preamble according to the PDCCH order through DCI format 1_0. The DCI format 1_0 for the PDCCH order may include random access preamble index indication information, UL / SUL (Uplink / Supplementary Uplink) indicator, SS / PBCH index indication information, PRACH mask index information, and reserved bits.

[0190] The terminal may preferentially select one type of RO from among at least one first RO and at least one second RO. That is, one RO for transmitting a random access preamble may be determined from at least one RO determined from among at least one first RO and at least one second RO.

[0191] In this case, at least one of the first RO and the second RO may be determined based on an instruction transmitted from the base station. The instruction received from the base station may include downlink control information including a PDCCH order. For example, DCI format 1_0 including the PDCCH order may include information indicating whether to determine a RACH OK based on the first RACH configuration information or whether to determine a RACH OK based on the second RACH configuration information.

[0192] The terminal may determine either the first RO or the second RO based on information included in the downlink control information. If the terminal determines the second RO, it may determine one RO among at least one second RO to transmit the random access preamble. The control unit (1310) may receive the random access preamble from the terminal in the determined RO.

[0193] Accordingly, a method and device for performing a random access procedure in an environment where full-duplex communication is applied can be provided.

[0194] The above-described embodiments may be supported by standard documents disclosed in at least one of the wireless access systems, IEEE 802, 3GPP, and 3GPP2. That is, steps, components, and parts not described in the present embodiments to clearly illustrate the technical concepts herein may be supported by the above-described standard documents. Furthermore, all terms disclosed in this specification may be explained by the above-described standard documents.

[0195] The embodiments described above may be implemented through various means. For example, the embodiments may be implemented through hardware, firmware, software, or a combination thereof.

[0196] In the case of hardware implementation, the method according to the present embodiments may be implemented by one or more ASICs (Application Specific Integrated Circuits), DSPs (Digital Signal Processors), DSPDs (Digital Signal Processing Devices), PLDs (Programmable Logic Devices), FPGAs (Field Programmable Gate Arrays), processors, controllers, microcontrollers, or microprocessors.

[0197] When implemented using firmware or software, the methods according to the present embodiments may be implemented in the form of devices, procedures, or functions that perform the functions or operations described above. The software code may be stored in a memory unit and executed by a processor. The memory unit may be located within or outside the processor and may exchange data with the processor using various known means.

[0198] Additionally, terms such as "system," "processor," "controller," "component," "module," "interface," "model," or "unit" as described above may generally refer to a computer-related entity, such as hardware, a combination of hardware and software, software, or software in execution. For example, the aforementioned components may be, but are not limited to, a process driven by a processor, a processor, a controller, a control processor, an object, a thread of execution, a program, and / or a computer. For example, both an application running on a controller or a processor and the controller or the processor may be components. One or more components may be within a process and / or thread of execution, and the components may be located on a single device (e.g., a system, a computing device, etc.) or distributed across two or more devices.

[0199] The above description is merely an illustrative example of the technical idea of ​​the present disclosure, and those skilled in the art to which the present disclosure pertains will appreciate that various modifications and variations can be made without departing from the essential characteristics of the technical idea of ​​the present disclosure. In addition, the present embodiments are not intended to limit the technical idea of ​​the present disclosure but rather to explain it, and therefore the scope of the technical idea of ​​the present disclosure is not limited by these embodiments. The scope of protection of the present disclosure should be interpreted by the claims below, and all technical ideas within a scope equivalent thereto should be interpreted as being included within the scope of the rights of the present disclosure.

[0200]

[0201] CROSS-REFERENCE TO RELATED APPLICATION

[0202] This patent application claims priority under 35 USC §119(a) to Korean Patent Application No. 10-2024-0022137, filed in Korea on February 15, 2024, and Korean Patent Application No. 10-2025-0019000, filed in Korea on February 13, 2025, the entire contents of which are incorporated herein by reference. In addition, this patent application claims priority in countries other than the United States for the same reasons, the entire contents of which are incorporated herein by reference.

Claims

1. In a method for a terminal to perform a random access procedure, A step of receiving random access channel (RACH) configuration information; A step of determining one of a plurality of random access channel occasions (RACH occasions; ROs) configured based on the above RACH configuration information; and Including a step of transmitting a random access preamble in the above-determined RO, A method wherein the RACH configuration information includes first RACH configuration information for configuring at least one first RO and second RACH configuration information for configuring at least one second RO for subband full duplex (SBFD).

2. In paragraph 1, At least one second RO is, A method used to determine the one RO through which the random access preamble is transmitted, when configured via an SBFD symbol.

3. In paragraph 1, The above one RO is, A method of determining at least one RO among the at least one first RO and the at least one second RO.

4. In paragraph 3, At least one RO determined among the at least one first RO and the at least one second RO, A method determined based on instructions transmitted from a base station.

5. In paragraph 4, Instructions received from the above base station are: A method including downlink control information including a PDCCH order.

6. In the method of performing a random access procedure by a base station, A step of transmitting random access channel (RACH) configuration information; and A step of receiving a random access preamble in one of a plurality of random access channel occasions (RACH occasions; ROs) configured based on the above RACH configuration information, A method wherein the RACH configuration information includes first RACH configuration information for configuring at least one first RO and second RACH configuration information for configuring at least one second RO for subband full duplex (SBFD).

7. In paragraph 6, At least one second RO is, A method for determining the one RO through which the random access preamble is received, when configured via an SBFD symbol.

8. In paragraph 6, The above one RO is, A method of determining at least one RO among the at least one first RO and the at least one second RO.

9. In paragraph 8, At least one RO determined among the at least one first RO and the at least one second RO, A method determined based on instructions transmitted from the above base station.

10. In paragraph 9, The instructions transmitted from the above base station are: A method including downlink control information including a PDCCH order.

11. In a terminal performing a random access procedure, Transmitter; Receiver; and Including a control unit that controls the operation of the above transmitter and receiver, The control unit receives random access channel (RACH) configuration information, determines one of a plurality of random access channel occasions (ROs) configured based on the RACH configuration information, and transmits a random access preamble in the determined RO. A terminal, wherein the RACH configuration information includes first RACH configuration information for configuring at least one first RO and second RACH configuration information for configuring at least one second RO for subband full duplex (SBFD).

12. In paragraph 11, At least one second RO is, A terminal used to determine the one RO through which the random access preamble is transmitted, when configured through an SBFD symbol.

13. In paragraph 11, The above one RO is, A terminal determined from among at least one RO determined from among the at least one first RO and the at least one second RO.

14. In paragraph 13, At least one RO determined among the at least one first RO and the at least one second RO, A terminal determined based on instructions transmitted from a base station.

15. In paragraph 14, Instructions received from the above base station are: A terminal including downlink control information including a PDCCH order.

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