Method and device for acquiring timing advance in communication system
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- SAMSUNG ELECTRONICS CO LTD
- Filing Date
- 2026-01-21
- Publication Date
- 2026-07-30
Smart Images
Figure KR2026001278_30072026_PF_FP_ABST
Abstract
Description
Method and device for obtaining timing advance in a communication system
[0001] The present disclosure generally relates to wireless communication systems, and more specifically to a method and apparatus for obtaining a timing advance in a wireless communication system.
[0002] 5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and can be implemented not only in frequency bands below 6 GHz ('Sub 6 GHz'), such as 3.5 gigahertz (3.5 GHz), but also in ultra-high frequency bands called millimeter waves (mmWave), such as 28 GHz and 39 GHz ('Above 6 GHz'). In addition, for 6G mobile communication technology, which is referred to as a system beyond 5G, implementation in the terahertz band (e.g., the 3 terahertz (3 THz) band at 95 GHz) is being considered to achieve transmission speeds 50 times faster and ultra-low latency reduced to one-tenth compared to 5G mobile communication technology.
[0003] In the early stages of 5G mobile communication technology, aiming to satisfy service support and performance requirements for enhanced Mobile BroadBand (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC), technologies such as beamforming and Massive MIMO to mitigate path loss and increase transmission distance in ultra-high frequency bands, support for various numerologies (such as the operation of multiple subcarrier spacings) and dynamic operation of slot formats for the efficient utilization of ultra-high frequency resources, initial access techniques to support multi-beam transmission and broadband, definition and operation of Band-Width Parts (BWP), Low Density Parity Check (LDPC) codes for high-volume data transmission, new channel coding methods such as Polar Codes for the reliable transmission of control information, and L2 pre-processing (L2 Standardization has been carried out for pre-processing, network slicing which provides a dedicated network specialized for specific services, and other methods.
[0004] Currently, discussions are underway to improve and enhance the performance of the initial 5G mobile communication technology, taking into account the services that the 5G mobile communication technology was intended to support. Additionally, standardization of the physical layer is in progress for technologies such as V2X (Vehicle-to-Everything), which helps autonomous vehicles make driving decisions and enhance user convenience based on their own location and status information transmitted by the vehicle; NR-U (New Radio Unlicensed), which aims for system operation in unlicensed bands to comply with various regulatory requirements; NR terminal low power consumption technology (UE Power Saving); Non-Terrestrial Network (NTN), which is direct terminal-satellite communication for securing coverage in areas where communication with the terrestrial network is impossible; and positioning.
[0005] In addition, standardization is underway in the field of wireless interface architecture / protocols for technologies such as the Industrial Internet of Things (IIoT) to support new services through linkage and convergence with other industries, Integrated Access and Backhaul (IAB) which provides nodes to expand network service areas by integrating wireless backhaul links and access links, Mobility Enhancement including Conditional Handover and Dual Active Protocol Stack (DAPS) Handover, and 2-step Random Access (2-step RACH for NR) which simplifies random access procedures. Standardization is also underway in the field of system architecture / services for 5G baseline architectures (e.g., Service based Architecture, Service based Interface) to incorporate Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC), which provides services based on the location of the terminal.
[0006] When such 5G mobile communication systems are commercialized, connected devices, which are increasing explosively, will be connected to communication networks. Accordingly, it is expected that there will be a need to enhance the functionality and performance of 5G mobile communication systems and to integrate the operation of connected devices. To this end, new research is planned to be conducted on 5G performance improvement and complexity reduction, support for AI services, support for metaverse services, and drone communication using eXtended Reality (XR), Artificial Intelligence (AI), and Machine Learning (ML) to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR).
[0007] Furthermore, the advancement of these 5G mobile communication systems encompasses multi-antenna transmission technologies such as new waveforms, Full Dimensional MIMO (FD-MIMO), array antennas, and large-scale antennas to guarantee coverage in the terahertz band of 6G mobile communication technology; metamaterial-based lenses and antennas; high-dimensional spatial multiplexing technology using Orbital Angular Momentum (OAM); and Reconfigurable Intelligent Surface (RIS) technology to improve terahertz band signal coverage; as well as full-duplex technology for enhancing frequency efficiency and system networks in 6G mobile communication technology; AI-based communication technologies that realize system optimization by utilizing satellites and Artificial Intelligence (AI) from the design stage and internalizing end-to-end AI support functions; and the realization of services of complexity exceeding the limits of terminal computing capabilities by utilizing ultra-high-performance communication and computing resources. It could serve as a foundation for the development of next-generation distributed computing technologies.
[0008] Various embodiments of the present disclosure may provide a method and apparatus for obtaining a timing advance in a wireless communication system.
[0009] The present disclosure relates to a method and apparatus for obtaining a timing advance in a communication system. More specifically, it relates to a method and apparatus for obtaining a timing advance in a terminal in which a conditional LTM is set.
[0010] The technical problems to be solved in the various embodiments of the present disclosure are not limited to those mentioned above, and other unmentioned technical problems may be considered by those skilled in the art from the various embodiments of the present disclosure described below.
[0011] According to one embodiment of the present disclosure, a method performed by a terminal in a communication system may be provided.
[0012] According to one embodiment of the present disclosure, the method comprises the steps of: receiving a setting associated with a conditional LTM (layer 1 / layer 2 (L1 / L2) triggered mobility) through upper layer signaling; receiving a PDCCH (physical downlink control channel) order that triggers a PRACH (physical random access channel) transmission (the PDCCH order includes a field indicating an LTM candidate cell associated with the conditional LTM); transmitting a PRACH preamble to the LTM candidate cell via the PRACH; monitoring a PDCCH (physical downlink control channel) for a RAR while a RAR (random access response) window is running; receiving the RAR via a PDSCH (physical downlink shared channel) based on the PDCCH; identifying that a TA (timing advance) value included in the RAR is for the LTM candidate cell; and It may include a step of starting a TAT (time alignment timer) associated with the above LTM candidate cell.
[0013] According to one embodiment of the present disclosure, the PDCCH includes downlink control information (DCI) for scheduling the PDSCH, a cyclic redundancy check (CRC) for the DCI is scrambled with a random access-radio network temporary identifier (RA-RNTI), and it is identified based on the RA-RNTI that the TA value included in the RAR is for the LTM candidate cell, and the initialization of the scrambling sequence for the PDSCH may be based on the RA-RNTI and the identifier of the source cell associated with the conditional LTM to which the PDSCH is transmitted.
[0014] According to one embodiment of the present disclosure, the RA-RNTI satisfies the following Equation 1 or Equation 2, and
[0015] [Mathematical Formula 1]
[0016] RA-RNTI = 1 + s_id + 14 × t_id + 14 × 80 × f_id + 14 × 80 × 8 × ul_carrier_id +14 × 80 × 8 × 2 × ltm-CandidateId,
[0017] [Mathematical Formula 2]
[0018] RA-RNTI = 1 + s_id + 14 × t_id + 14 × 80 × f_id + 14 × 80 × 8 × ul_carrier_id +14 × 80 × 8 × 2 × Cell_indicator,
[0019] The above s_id is the first OFDM (othogonal frequency division multiplexing) symbol index of the PRACH occasion in which the PRACH preamble was transmitted, the above t_id is the first slot index of the PRACH occasion within the system frame in which the PRACH preamble was transmitted, the above f_id is the frequency axis index of the PRACH occasion in which the PRACH preamble was transmitted, the above ul_carrier_id is the index of the uplink carrier in which the PRACH preamble was transmitted, the above ltm-CandidateId is the index of the cell in which the PRACH preamble was transmitted corresponding to a value for the index of one or more LTM candidate cells included in the configuration associated with the LTM, and the above Cell_indicator may be the index of the cell in which the PRACH preamble was transmitted corresponding to a value for a field indicating the LTM candidate cell.
[0020] According to one embodiment of the present disclosure, the RAR includes a field associated with a cell corresponding to the TA value, and the field associated with the cell corresponds to a value for an index of one or more LTM candidate cells included in a setting associated with the LTM, or corresponds to a value for a field indicating the LTM candidate cell, and it can be identified that the TA value included in the RAR is for the LTM candidate cell based on the field associated with the cell corresponding to the TA value.
[0021] According to one embodiment of the present disclosure, it is assumed that the PDCCH DM-RS (demodulation reference signal) for the PDCCH for the RAR is a specific DL RS (downlink reference signal) and QCL (quasi co-located), and the PDSCH DM-RS for the PDSCH is assumed to be the PDCCH DM-RS and QCL, and the specific DL RS includes the PDCCH DM-RS for the PDCCH command, the SS / PBCH (synchronization signal / physical broadcast channel) block or CSI-RS (channel state information reference signal) associated with the PRACH preamble, the index of the SS / PBCH block is identified based on the PDCCH command, the SS / PBCH block is received from the LTM candidate cell, the index of the CSI-RS resource corresponding to the CSI-RS is identified based on the PDCCH command, and the CSI-RS can be received from the LTM candidate cell.
[0022] According to one embodiment of the present disclosure, the method further comprises the step of performing an operation related to RACH-less-based mobility to the LTM candidate cell based on the TA value when a conditional LTM condition related to the LTM candidate cell is satisfied while the TAT is running, and the conditional LTM condition may be included in one or more conditional LTM conditions included in the settings related to the LTM.
[0023] According to one embodiment of the present disclosure, a terminal of a communication system may be provided.
[0024] According to one embodiment of the present disclosure, the terminal includes a transceiver and a processor connected to the transceiver, and the processor receives a setting related to a conditional LTM (layer 1 / layer 2 (L1 / L2) triggered mobility) through upper layer signaling, receives a PDCCH (physical downlink control channel) order that triggers a PRACH (physical random access channel) transmission (the PDCCH order includes a field indicating an LTM candidate cell related to the conditional LTM), transmits a PRACH preamble to the LTM candidate cell via the PRACH, monitors the PDCCH (physical downlink control channel) for the RAR while the RAR (random access response) window is running, receives the RAR via the PDSCH (physical downlink shared channel) based on the PDCCH, and the TA (timing advance) included in the RAR It can be identified that the value is for the LTM candidate cell and set to start the TAT (time alignment timer) associated with the LTM candidate cell.
[0025] According to one embodiment of the present disclosure, the PDCCH includes downlink control information (DCI) for scheduling the PDSCH, a cyclic redundancy check (CRC) for the DCI is scrambled with a random access-radio network temporary identifier (RA-RNTI), and it is identified based on the RA-RNTI that the TA value included in the RAR is for the LTM candidate cell, and the initialization of the scrambling sequence for the PDSCH may be based on the RA-RNTI and the identifier of the source cell associated with the conditional LTM to which the PDSCH is transmitted.
[0026] According to one embodiment of the present disclosure, the RA-RNTI satisfies the following Equation 1 or Equation 2, and
[0027] [Mathematical Formula 1]
[0028] RA-RNTI = 1 + s_id + 14 × t_id + 14 × 80 × f_id + 14 × 80 × 8 × ul_carrier_id +14 × 80 × 8 × 2 × ltm-CandidateId,
[0029] [Mathematical Formula 2]
[0030] RA-RNTI = 1 + s_id + 14 × t_id + 14 × 80 × f_id + 14 × 80 × 8 × ul_carrier_id +14 × 80 × 8 × 2 × Cell_indicator,
[0031] The above s_id is the first OFDM (othogonal frequency division multiplexing) symbol index of the PRACH occasion in which the PRACH preamble was transmitted, the above t_id is the first slot index of the PRACH occasion within the system frame in which the PRACH preamble was transmitted, the above f_id is the frequency axis index of the PRACH occasion in which the PRACH preamble was transmitted, the above ul_carrier_id is the index of the uplink carrier in which the PRACH preamble was transmitted, the above ltm-CandidateId is the index of the cell in which the PRACH preamble was transmitted corresponding to a value for the index of one or more LTM candidate cells included in the configuration associated with the LTM, and the above Cell_indicator may be the index of the cell in which the PRACH preamble was transmitted corresponding to a value for a field indicating the LTM candidate cell.
[0032] According to one embodiment of the present disclosure, the RAR includes a field associated with a cell corresponding to the TA value, and the field associated with the cell corresponds to a value for an index of one or more LTM candidate cells included in a setting associated with the LTM, or corresponds to a value for a field indicating the LTM candidate cell, and it can be identified that the TA value included in the RAR is for the LTM candidate cell based on the field associated with the cell corresponding to the TA value.
[0033] According to one embodiment of the present disclosure, it is assumed that the PDCCH DM-RS (demodulation reference signal) for the PDCCH for the RAR is a specific DL RS (downlink reference signal) and QCL (quasi co-located), and the PDSCH DM-RS for the PDSCH is assumed to be the PDCCH DM-RS and QCL, and the specific DL RS includes the PDCCH DM-RS for the PDCCH command, the SS / PBCH (synchronization signal / physical broadcast channel) block or CSI-RS (channel state information reference signal) associated with the PRACH preamble, the index of the SS / PBCH block is identified based on the PDCCH command, the SS / PBCH block is received from the LTM candidate cell, the index of the CSI-RS resource corresponding to the CSI-RS is identified based on the PDCCH command, and the CSI-RS can be received from the LTM candidate cell.
[0034] According to one embodiment of the present disclosure, the processor is configured to perform an operation related to RACH-less-based mobility to the LTM candidate cell based on the TA value when a conditional LTM condition related to the LTM candidate cell is satisfied while the TAT is running, and the conditional LTM condition may be included in one or more conditional LTM conditions included in the setting related to the LTM.
[0035] According to one embodiment of the present disclosure, a method performed by a base station in a communication system may be provided.
[0036] According to one embodiment of the present disclosure, the method comprises the steps of: transmitting a setting associated with a conditional LTM (layer 1 / layer 2 (L1 / L2) triggered mobility) through upper layer signaling; transmitting a PDCCH (physical downlink control channel) order that triggers a PRACH (physical random access channel) transmission (the PDCCH order includes a field indicating an LTM candidate cell associated with the conditional LTM); receiving a PRACH preamble through the PRACH at the LTM candidate cell; transmitting a PDCCH (physical downlink control channel) for a RAR while a RAR (random access response) window is running; transmitting the RAR through a PDSCH (physical downlink shared channel) (the TA (timing advance) value included in the RAR is for the LTM candidate cell); and the LTM candidate cell associated It may include a step to start the TAT (time alignment timer).
[0037] According to one embodiment of the present disclosure, the PDCCH includes downlink control information (DCI) for scheduling the PDSCH, a cyclic redundancy check (CRC) for the DCI is scrambled with a random access-radio network temporary identifier (RA-RNTI), and the TA value included in the RAR is indicated based on the RA-RNTI as being for the LTM candidate cell, and the initialization of the scrambling sequence for the PDSCH may be based on the RA-RNTI and the identifier of the source cell associated with the conditional LTM to which the PDSCH is transmitted.
[0038] According to one embodiment of the present disclosure, the RA-RNTI satisfies the following Equation 1 or Equation 2, and
[0039] [Mathematical Formula 1]
[0040] RA-RNTI = 1 + s_id + 14 × t_id + 14 × 80 × f_id + 14 × 80 × 8 × ul_carrier_id +14 × 80 × 8 × 2 × ltm-CandidateId,
[0041] [Mathematical Formula 2]
[0042] RA-RNTI = 1 + s_id + 14 × t_id + 14 × 80 × f_id + 14 × 80 × 8 × ul_carrier_id +14 × 80 × 8 × 2 × Cell_indicator,
[0043] The above s_id is the first OFDM (othogonal frequency division multiplexing) symbol index of the PRACH occasion in which the PRACH preamble was received, the above t_id is the first slot index of the PRACH occasion within the system frame in which the PRACH preamble was received, the above f_id is the frequency axis index of the PRACH occasion in which the PRACH preamble was received, the above ul_carrier_id is the index of the uplink carrier in which the PRACH preamble was received, the above ltm-CandidateId is the index of the cell in which the PRACH preamble was received corresponding to a value for the index of one or more LTM candidate cells included in the configuration associated with the LTM, and the above Cell_indicator may be the index of the cell in which the PRACH preamble was received corresponding to a value for a field indicating the LTM candidate cell.
[0044] According to one embodiment of the present disclosure, the RAR includes a field associated with a cell corresponding to the TA value, and the field associated with the cell corresponds to a value for an index of one or more LTM candidate cells included in a setting associated with the LTM, or corresponds to a value for a field indicating the LTM candidate cell, and the TA value included in the RAR is for the LTM candidate cell may be indicated based on the field associated with the cell corresponding to the TA value.
[0045] According to one embodiment of the present disclosure, it is assumed that the PDCCH DM-RS (demodulation reference signal) for the PDCCH for the RAR is a specific DL RS (downlink reference signal) and QCL (quasi co-located), and the PDSCH DM-RS for the PDSCH is assumed to be the PDCCH DM-RS and QCL, and the specific DL RS includes the PDCCH DM-RS for the PDCCH command, the SS / PBCH (synchronization signal / physical broadcast channel) block or CSI-RS (channel state information reference signal) associated with the PRACH preamble, the index of the SS / PBCH block is indicated based on the PDCCH command, the SS / PBCH block is transmitted in the LTM candidate cell, the index of the CSI-RS resource corresponding to the CSI-RS is identified based on the PDCCH command, and the CSI-RS can be transmitted in the LTM candidate cell.
[0046] According to one embodiment of the present disclosure, a base station of a communication system may be provided.
[0047] According to one embodiment of the present disclosure, the base station includes a transceiver and a processor connected to the transceiver, and the processor transmits a setting related to a conditional LTM (layer 1 / layer 2 (L1 / L2) triggered mobility) through upper layer signaling, transmits a PDCCH (physical downlink control channel) order that triggers a PRACH (physical random access channel) transmission (the PDCCH order includes a field indicating an LTM candidate cell related to the conditional LTM), receives a PRACH preamble from the LTM candidate cell via PRACH, transmits a PDCCH (physical downlink control channel) for a RAR while a RAR (random access response) window is running, transmits the RAR via a PDSCH (physical downlink shared channel) (the TA (timing advance) value included in the RAR is the LTM candidate (This is for the cell), and can be set to start the TAT (time alignment timer) associated with the above LTM candidate cell.
[0048] According to one embodiment of the present disclosure, the PDCCH includes downlink control information (DCI) for scheduling the PDSCH, a cyclic redundancy check (CRC) for the DCI is scrambled with a random access-radio network temporary identifier (RA-RNTI), and the TA value included in the RAR is indicated based on the RA-RNTI as being for the LTM candidate cell, and the initialization of the scrambling sequence for the PDSCH may be based on the RA-RNTI and the identifier of the source cell associated with the conditional LTM to which the PDSCH is transmitted.
[0049] According to one embodiment of the present disclosure, the RA-RNTI satisfies the following Equation 1 or Equation 2, and
[0050] [Mathematical Formula 1]
[0051] RA-RNTI = 1 + s_id + 14 × t_id + 14 × 80 × f_id + 14 × 80 × 8 × ul_carrier_id +14 × 80 × 8 × 2 × ltm-CandidateId,
[0052] [Mathematical Formula 2]
[0053] RA-RNTI = 1 + s_id + 14 × t_id + 14 × 80 × f_id + 14 × 80 × 8 × ul_carrier_id +14 × 80 × 8 × 2 × Cell_indicator,
[0054] The above s_id is the first OFDM (othogonal frequency division multiplexing) symbol index of the PRACH occasion in which the PRACH preamble was received, the above t_id is the first slot index of the PRACH occasion within the system frame in which the PRACH preamble was received, the above f_id is the frequency axis index of the PRACH occasion in which the PRACH preamble was received, the above ul_carrier_id is the index of the uplink carrier in which the PRACH preamble was received, the above ltm-CandidateId is the index of the cell in which the PRACH preamble was received corresponding to a value for the index of one or more LTM candidate cells included in the configuration associated with the LTM, and the above Cell_indicator may be the index of the cell in which the PRACH preamble was received corresponding to a value for a field indicating the LTM candidate cell.
[0055] According to one embodiment of the present disclosure, the RAR includes a field associated with a cell corresponding to the TA value, and the field associated with the cell corresponds to a value for an index of one or more LTM candidate cells included in a setting associated with the LTM, or corresponds to a value for a field indicating the LTM candidate cell, and the TA value included in the RAR is for the LTM candidate cell may be indicated based on the field associated with the cell corresponding to the TA value.
[0056] According to one embodiment of the present disclosure, it is assumed that the PDCCH DM-RS (demodulation reference signal) for the PDCCH for the RAR is a specific DL RS (downlink reference signal) and QCL (quasi co-located), and the PDSCH DM-RS for the PDSCH is assumed to be the PDCCH DM-RS and QCL, and the specific DL RS includes the PDCCH DM-RS for the PDCCH command, the SS / PBCH (synchronization signal / physical broadcast channel) block or CSI-RS (channel state information reference signal) associated with the PRACH preamble, the index of the SS / PBCH block is indicated based on the PDCCH command, the SS / PBCH block is transmitted in the LTM candidate cell, the index of the CSI-RS resource corresponding to the CSI-RS is identified based on the PDCCH command, and the CSI-RS can be transmitted in the LTM candidate cell.
[0057] According to one embodiment of the present disclosure, a method performed by a terminal in a communication system may be provided.
[0058] According to one embodiment of the present disclosure, the method may include the steps of: receiving a setting associated with a conditional LTM (layer 1 / layer 2 (L1 / L2) triggered mobility) through upper layer signaling; receiving a PDCCH (physical downlink control channel) order that triggers a PRACH (physical random access channel) transmission (the PDCCH order includes a field indicating an LTM candidate cell associated with the conditional LTM); transmitting a PRACH preamble to the LTM candidate cell through the PRACH; receiving a MAC CE (medium access control control element) through a PDSCH (physical downlink shared channel) after the transmission of the PRACH preamble; identifying that a TA (timing advance) value included in the MAC CE is for the LTM candidate cell; and starting a TAT (time alignment timer) associated with the LTM candidate cell.
[0059] According to one embodiment of the present disclosure, the MAC CE includes a field associated with a cell corresponding to the TA value, the field associated with the cell corresponds to a value for an index of one or more LTM candidate cells included in a setting associated with the LTM, or corresponds to a value for a field indicating the LTM candidate cell, and the TA value included in the RAR is for the LTM candidate cell can be identified based on the field associated with the cell corresponding to the TA value.
[0060] According to one embodiment of the present disclosure, the method further comprises the step of performing an operation related to RACH-less-based mobility to the LTM candidate cell based on the TA value when a conditional LTM condition related to the LTM candidate cell is satisfied while the TAT is running, and the conditional LTM condition may be included in one or more conditional LTM conditions included in the settings related to the LTM.
[0061] According to one embodiment of the present disclosure, a terminal of a communication system may be provided.
[0062] According to one embodiment of the present disclosure, the terminal includes a transceiver and a processor connected to the transceiver, and the processor receives a setting related to a conditional LTM (layer 1 / layer 2 (L1 / L2) triggered mobility) through upper layer signaling, receives a PDCCH (physical downlink control channel) order that triggers a PRACH (physical random access channel) transmission (the PDCCH order includes a field indicating an LTM candidate cell related to the conditional LTM), transmits a PRACH preamble to the LTM candidate cell via PRACH, receives a MAC CE (medium access control control element) via PDSCH (physical downlink shared channel) after the transmission of the PRACH preamble, identifies that a TA (timing advance) value included in the MAC CE is for the LTM candidate cell, and starts a TAT (time alignment timer) related to the LTM candidate cell. It can be set.
[0063] According to one embodiment of the present disclosure, the MAC CE includes a field associated with a cell corresponding to the TA value, the field associated with the cell corresponds to a value for an index of one or more LTM candidate cells included in a setting associated with the LTM, or corresponds to a value for a field indicating the LTM candidate cell, and the TA value included in the RAR is for the LTM candidate cell can be identified based on the field associated with the cell corresponding to the TA value.
[0064] According to one embodiment of the present disclosure, the processor is configured to perform an operation related to RACH-less-based mobility to the LTM candidate cell based on the TA value when a conditional LTM condition related to the LTM candidate cell is satisfied while the TAT is running, and the conditional LTM condition may be included in one or more conditional LTM conditions included in the setting related to the LTM.
[0065] According to one embodiment of the present disclosure, a method performed by a base station in a communication system may be provided.
[0066] According to one embodiment of the present disclosure, the method may include the steps of: transmitting a setting associated with a conditional LTM (layer 1 / layer 2 (L1 / L2) triggered mobility) through upper layer signaling; transmitting a PDCCH (physical downlink control channel) order that triggers a PRACH (physical random access channel) transmission (the PDCCH order includes a field indicating an LTM candidate cell associated with the conditional LTM); receiving a RACH preamble through the PRACH at the LTM candidate cell; transmitting a MAC CE (medium access control control element) through the PDSCH (physical downlink shared channel) (the TA (timing advance) value included in the MAC CE is for the LTM candidate cell); and starting a TAT (time alignment timer) associated with the LTM candidate cell.
[0067] According to one embodiment of the present disclosure, the MAC CE includes a field associated with a cell corresponding to the TA value, the field associated with the cell corresponds to a value for an index of one or more LTM candidate cells included in a setting associated with the LTM, or corresponds to a value for a field indicating the LTM candidate cell, and the TA value included in the RAR may be indicated as being for the LTM candidate cell based on the field associated with the cell corresponding to the TA value.
[0068] According to one embodiment of the present disclosure, a base station of a communication system may be provided.
[0069] According to one embodiment of the present disclosure, the base station includes a transceiver and a processor connected to the transceiver, and the processor may be configured to transmit a setting related to a conditional LTM (layer 1 / layer 2 (L1 / L2) triggered mobility) through upper layer signaling, transmit a PDCCH (physical downlink control channel) order that triggers a PRACH (physical random access channel) transmission (the PDCCH order includes a field indicating an LTM candidate cell related to the conditional LTM), receive a RACH preamble from the LTM candidate cell through the PRACH, transmit a MAC CE (medium access control control element) through the PDSCH (physical downlink shared channel) (the TA (timing advance) value included in the MAC CE is for the LTM candidate cell), and start a TAT (time alignment timer) related to the LTM candidate cell.
[0070] According to one embodiment of the present disclosure, the MAC CE includes a field associated with a cell corresponding to the TA value, the field associated with the cell corresponds to a value for an index of one or more LTM candidate cells included in a setting associated with the LTM, or corresponds to a value for a field indicating the LTM candidate cell, and the TA value included in the RAR may be indicated as being for the LTM candidate cell based on the field associated with the cell corresponding to the TA value.
[0071] The various embodiments of the present disclosure described above are merely some of the preferred embodiments of the present disclosure, and various embodiments reflecting the technical features of the various embodiments of the present disclosure can be derived and understood by those skilled in the art based on the detailed description to be described below.
[0072] Various embodiments of the present disclosure may provide a method and apparatus for obtaining a timing advance in a wireless communication system.
[0073] Various embodiments of the present disclosure may provide a method and apparatus for obtaining a timing advance at a terminal in which a conditional LTM is set.
[0074] Various embodiments of the present disclosure may provide a method and apparatus for identifying / indicating which candidate cell a TA indicated to a terminal with a conditional LTM set is for.
[0075] The effects obtainable from the various embodiments of the present disclosure are not limited to those mentioned above, and other unmentioned effects can be clearly derived and understood by those skilled in the art based on the following detailed description.
[0076] The drawings attached below are intended to aid in understanding various embodiments of the present disclosure and provide various embodiments of the present disclosure together with the detailed description. However, the technical features of the various embodiments of the present disclosure are not limited to specific drawings, and the features disclosed in each drawing may be combined with one another to form new embodiments. Reference numerals in each drawing denote structural elements.
[0077] FIG. 1 is a drawing illustrating the structure of a wireless communication system according to one embodiment of the present disclosure.
[0078] FIG. 2 is a diagram illustrating the wireless protocol structure of a wireless communication system according to one embodiment of the present disclosure.
[0079] FIG. 3 is a diagram illustrating the basic structure of the time-frequency domain, which is a wireless resource domain in which data or a control channel is transmitted in a wireless communication system according to one embodiment of the present disclosure.
[0080] FIG. 4 is a drawing illustrating an example of a slot structure considered in a wireless communication system according to one embodiment of the present disclosure.
[0081] FIG. 5 is a drawing illustrating an example of a setting for a bandwidth portion in a wireless communication system according to one embodiment of the present disclosure.
[0082] FIG. 6 is a drawing for explaining carrier aggregation (CA) according to one embodiment of the present disclosure.
[0083] FIG. 7 is a diagram illustrating an example of a cross-carrier scheduling method according to one embodiment of the present disclosure.
[0084] FIG. 8 is a diagram illustrating an example of setting a control resource set (CORESET) of a downlink control channel in a wireless communication system according to one embodiment of the present disclosure.
[0085] FIG. 9 is a diagram illustrating an example of processing a physical downlink shared channel in a wireless communication system according to an embodiment of the present disclosure. FIG. 10 is a diagram illustrating an example of a method for obtaining the size of a transport block in a wireless communication system according to an embodiment of the present disclosure.
[0086] FIG. 11a is a diagram illustrating the uplink-downlink resource configuration of an XDD system that flexibly divides uplink and downlink resources in the time domain and frequency domain according to one embodiment of the present disclosure.
[0087] FIG. 11b is a diagram illustrating an example of an uplink-downlink resource configuration of a full-duplex communication system in which uplink and downlink resources are flexibly divided in the time domain and the frequency domain according to one embodiment of the present disclosure.
[0088] FIG. 11c is a drawing illustrating a transmission and reception structure for a duplex method according to one embodiment of the present disclosure.
[0089] Figure 11d is a diagram illustrating an example of downlink and uplink resource configuration in an XDD system.
[0090] FIG. 11e is a diagram illustrating an example of SBFD operating in the TDD band of a wireless communication system to which the present disclosure applies.
[0091] FIG. 11f is a drawing illustrating an SBFD setting according to one embodiment of the present disclosure.
[0092] FIG. 12 is a drawing illustrating an example of a non-SBFD symbol of a wireless communication system according to one embodiment of the present disclosure.
[0093] FIG. 13 is a drawing illustrating an example of an SBFD symbol of a wireless communication system according to one embodiment of the present disclosure.
[0094] FIG. 14 is a drawing illustrating an example of an SBFD symbol of a wireless communication system according to one embodiment of the present disclosure.
[0095] FIG. 15 is a drawing illustrating an example of an SBFD symbol of a wireless communication system according to one embodiment of the present disclosure.
[0096] FIG. 16 is a drawing illustrating an example of slots of a wireless communication system according to one embodiment of the present disclosure.
[0097] FIG. 17 is a drawing illustrating an example of slots of a wireless communication system according to one embodiment of the present disclosure.
[0098] FIG. 18 illustrates an example of a conditional handover operation according to one embodiment of the present disclosure.
[0099] FIG. 19 illustrates an example of LTM operation according to one embodiment of the present disclosure.
[0100] FIG. 20 illustrates an example of a conditional LTM operation according to one embodiment of the present disclosure.
[0101] FIG. 21 illustrates an example of an operation in which a terminal checks a TA value in a (conditional) LTM according to one embodiment of the present disclosure.
[0102] FIG. 22 illustrates an example of an operation in which a terminal checks a TA value in a (conditional) LTM according to one embodiment of the present disclosure.
[0103] FIG. 23 illustrates an example of an operation in which a terminal checks a TA value in a (conditional) LTM according to one embodiment of the present disclosure.
[0104] FIG. 24 illustrates an example of an operation in which a terminal determines a QCL attribute in a (conditional) LTM according to one embodiment of the present disclosure.
[0105] FIG. 25 illustrates an example of a time alignment timer-related operation in a (conditional) LTM according to one embodiment of the present disclosure.
[0106] FIG. 26 is a drawing illustrating the structure of a terminal in a wireless communication system according to one embodiment of the present disclosure.
[0107] FIG. 27 is a drawing illustrating the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.
[0108] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings.
[0109] In describing the embodiments, technical details that are well known in the art to which this disclosure belongs and are not directly related to this disclosure are omitted. This is intended to convey the essence of this disclosure more clearly without obscuring it by omitting unnecessary explanations.
[0110] For the same reason, some components in the attached drawings have been exaggerated, omitted, or schematically depicted. Additionally, the size of each component does not entirely reflect its actual dimensions. Identical or corresponding components in each drawing have been assigned the same reference number.
[0111] The advantages and features of the present disclosure and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below but may be implemented in various different forms. The embodiments of the present disclosure are provided merely to make the present disclosure complete and to fully inform those skilled in the art of the scope of the present disclosure, and the present disclosure is defined only by the scope of the claims. Throughout the specification, like reference numerals refer to like components.
[0112] At this point, it will be understood that each block of the process flow diagrams and combinations of the flow diagrams can be executed by computer program instructions. Since these computer program instructions can be loaded into the processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, the instructions executed through the processor of the computer or other programmable data processing equipment create means to perform the functions described in the flow diagram block(s). Since these computer program instructions can also be stored in computer-available or computer-readable memory that can be directed toward the computer or other programmable data processing equipment to implement the function in a specific way, the instructions stored in computer-available or computer-readable memory can also produce a manufactured item containing means of instruction to perform the function described in the flow diagram block(s). Since computer program instructions can be loaded onto a computer or other programmable data processing equipment, instructions that execute a computer or other programmable data processing equipment by performing a series of operation steps on the computer or other programmable data processing equipment to create a process executed by the computer may also provide steps for executing the functions described in the flowchart block(s).
[0113] Additionally, each block may represent a module, segment, or part of code containing one or more executable instructions for executing a specific logical function(s). It should also be noted that in some alternative execution examples, the functions mentioned in the blocks may occur out of order. For instance, two blocks described in succession may actually be executed substantially simultaneously, or the blocks may be executed in reverse order depending on the corresponding function.
[0114] In this embodiment, the term "part" as used refers to a software or hardware component such as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit), and the "part" performs certain roles. However, the meaning of "part" is not limited to software or hardware. The "part" may be configured to reside in an addressable storage medium or may be configured to run one or more processors. Accordingly, according to some embodiments, the "part" includes components such as software components, object-oriented software components, class components, and task components, as well as processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and "parts" may be combined into a smaller number of components and "parts" or further separated into additional components and "parts." In addition, the components and 'parts' may be implemented to utilize one or more CPUs within the device or secure multimedia card. Also, according to some embodiments, the 'parts' may include one or more processors.
[0115] Efforts are being made to develop improved 5G or pre-5G communication systems to meet the increasing demand for wireless data traffic since the commercialization of 4G communication systems. For this reason, 5G or pre-5G communication systems are referred to as systems beyond the 4G network or systems following the LTE (long term evolution) system. To achieve high data transmission rates, the implementation of 5G communication systems in the mmWave band (e.g., the 60 GHz band) is being considered. To mitigate path loss and increase transmission distance in the mmWave band, technologies such as beamforming, massive MIMO, full Dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and large-scale antennas are being discussed for 5G communication systems. In addition, to improve the network of the system, the development of technologies such as advanced small cell, advanced small cell, cloud radio access network (cloud RAN), ultra-dense network, Device to Device communication (D2D), wireless backhaul, moving network, cooperative communication, CoMP (Coordinated Multi-Points), and interference cancellation is taking place in 5G communication systems.In addition, advanced coding modulation (ACM) methods such as FQAM (Hybrid FSK and QAM Modulation) and SWSC (Sliding Window Superposition Coding), as well as advanced access technologies such as FBMC (Filter Bank Multi Carrier), NOMA (non-orthogonal multiple access), and SCMA (sparse code multiple access), are being developed in 5G systems.
[0116] Meanwhile, the Internet is evolving from a human-centered network where humans generate and consume information into an IoT (Internet of Things) network where distributed components, such as objects, exchange and process information. IoE (Internet of Everything) technology, which combines IoT with Big Data processing technologies through connections with cloud servers, is also emerging. To implement IoT, technological elements such as sensing technology, wired and wireless communication and network infrastructure, service interface technology, and security technology are required; consequently, technologies such as sensor networks, Machine-to-Machine (M2M) communication, and Machine-Type Communication (MTC) are currently being researched to facilitate the connection of objects. In an IoT environment, intelligent IT services that create new value for human life by collecting and analyzing data generated from connected objects can be provided. Through the convergence and integration of existing IT technologies with various industries, IoT can be applied to fields such as smart homes, smart buildings, smart cities, smart or connected cars, smart grids, healthcare, smart home appliances, and advanced medical services.
[0117] Accordingly, various attempts are being made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, Machine to Machine (M2M), and Machine Type Communication (MTC) are being implemented using 5G communication techniques such as beamforming, MIMO, and array antennas. The application of cloud RAN as a big data processing technology, as previously described, can also be considered an example of the convergence of 5G and IoT technologies.
[0118] The operating principles of the present disclosure will be described in detail below with reference to the attached drawings. In describing the present disclosure below, if it is determined that a detailed description of related known functions or configurations might unnecessarily obscure the essence of the present disclosure, such detailed description will be omitted. Furthermore, the terms described below are defined in consideration of their functions in the present disclosure, and these may vary depending on the intentions or conventions of the user or operator. Therefore, such definitions should be based on the content throughout this specification. Hereinafter, a base station is an entity that performs resource allocation for terminals and may be at least one of a gNode B, eNode B, Node B, BS (Base Station), wireless access unit, base station controller, or a node on a network. A terminal may include a UE (User Equipment), MS (Mobile Station), cellular phone, smartphone, computer, or a multimedia system capable of performing communication functions. Of course, it is not limited to the above examples. Hereinafter, the present disclosure describes a technology for a terminal to receive broadcast information from a base station in a wireless communication system. The present disclosure relates to a communication technique and a system for integrating a 5G (5th generation) communication system with IoT (Internet of Things) technology to support higher data transmission rates than those of 4G (4th generation) systems. The present disclosure can be applied to intelligent services (e.g., smart homes, smart buildings, smart cities, smart cars or connected cars, healthcare, digital education, retail, security and safety-related services, etc.) based on 5G communication technology and IoT-related technology.
[0119] Terms used in the following description to refer to broadcast information, control information, communication coverage, state changes (e.g., events), network entities, messages, and device components are examples provided for the convenience of explanation. Accordingly, the present disclosure is not limited to the terms described below, and other terms having equivalent technical meanings may be used.
[0120] For convenience of explanation below, some terms and names defined in the 3GPP LTE (3rd generation partnership project long term evolution) standard or 3GPP NR (new radio or new radio access technology) may be used. However, the present disclosure is not limited by the above terms and names and can be equally applied to systems conforming to other standards.
[0121] FIG. 1 is a drawing illustrating the structure of a next-generation mobile communication system according to one embodiment of the present disclosure.
[0122] Referring to FIG. 1, the wireless access network of a next-generation mobile communication system (hereinafter NR or 5G) may be composed of a next-generation base station (new radio node B, hereinafter NR gNB or NR base station) (110) and a next-generation wireless core network (new radio core network, NR CN) (105). A next-generation wireless user terminal (new radio user equipment, NR UE or terminal) (115) may connect to an external network through the NR gNB (110) and the NR CN (105).
[0123] In FIG. 1, the NR gNB (110) can correspond to the eNB (evolved node B) of the existing LTE system. The NR gNB is connected to the NR UE (115) via a wireless channel and can provide a service that is more advanced than that of the existing node B. In the next-generation mobile communication system, all user traffic can be serviced through a shared channel. Therefore, a device is required to collect state information such as the buffer status, available transmission power status, and channel status of the UEs and perform scheduling, and the NR gNB (110) can handle this. A single NR gNB can control multiple cells. In the next-generation mobile communication system, a bandwidth greater than the current maximum bandwidth can be applied to achieve ultra-high-speed data transmission compared to current LTE. Additionally, beamforming technology can be incorporated by using orthogonal frequency division multiplexing (OFDM) as the wireless access technology. In addition, an adaptive modulation & doding (hereinafter referred to as AMC) scheme that determines the modulation scheme and channel coding rate according to the channel conditions of the terminal may be applied.
[0124] The NR CN (105) can perform functions such as mobility support, bearer configuration, and QoS configuration. The NR CN is a device responsible for various control functions as well as mobility management functions for terminals, and can be connected to multiple base stations. In addition, the next-generation mobile communication system can be interoperable with existing LTE systems, and the NR CN can be connected to the MME (125) via a network interface. The MME can be connected to the existing base station eNB (130).
[0125] FIG. 2 is a diagram illustrating the wireless protocol structure of a next-generation mobile communication system according to one embodiment of the present disclosure.
[0126] Referring to FIG. 2, the wireless protocol of the next-generation mobile communication system consists of an NR service data adaptation protocol (SDAP) (201, 245), an NR packet data convergence protocol (PDCP) (205, 240), an NR RLC (210, 235), an NR MAC (medium access control) (215, 230), and an NR PHY (physical) (220, 225) at the terminal and the NR base station, respectively.
[0127] The main functions of NR SDAP (201, 245) may include some of the following functions.
[0128] - User data transfer function (transfer of user plane data)
[0129] - Mapping function between a QoS flow and a DRB for both DL and UL for uplink and downlink
[0130] - Marking QoS flow ID in both DL and UL packets for uplink and downlink
[0131] - Function to map reflective QoS flow to data bearers for uplink SDAP PDUs (reflective QoS flow to DRB mapping for the UL SDAP PDUs).
[0132] For SDAP layer devices, the terminal may receive a radio resource control (RRC) message indicating whether to use the SDAP layer device header or the SDAP layer device functions for each PDCP layer device, bearer, or logical channel. If the SDAP header is configured, the terminal may be instructed to update or reset the mapping information for the uplink and downlink QoS flows and data bearers using the 1-bit NAS reflective QoS indicator and the 1-bit AS reflective QoS indicator of the SDAP header. The SDAP header may include QoS flow ID information indicating QoS. The QoS information may be used for data processing priorities, scheduling information, etc., to support seamless service.
[0133] The main functions of NR PDCP (205, 240) may include some of the following functions.
[0134] - Header compression and decompression features (ROHC only)
[0135] - User data transfer function (Transfer of user data)
[0136] - Sequential delivery function (In-sequence delivery of upper layer PDUs)
[0137] - Out-of-sequence delivery of upper layer PDUs
[0138] - Reordering function (PDCP PDU reordering for reception)
[0139] - Duplicate detection function (Duplicate detection of lower layer SDUs)
[0140] - Retransmission of PDCP SDUs
[0141] - Encryption and decryption functions (Ciphering and deciphering)
[0142] - Timer-based SDU discard in uplink.
[0143] In the above description, the reordering function of the NR PDCP device may refer to a function that reorders PDCP PDUs received from a lower layer in order based on the PDCP SN (sequence number). The reordering function of the NR PDCP device may include a function to transmit data to an upper layer in the reordered order, a function to transmit immediately without considering the order, a function to record lost PDCP PDUs by reordering, a function to report the status of lost PDCP PDUs to the transmitting side, and a function to request retransmission of lost PDCP PDUs.
[0144] The main functions of NR RLC (210, 235) may include some of the following functions.
[0145] - Data transfer function (Transfer of upper layer PDUs)
[0146] - Sequential delivery function (In-sequence delivery of upper layer PDUs)
[0147] - Out-of-sequence delivery of upper layer PDUs
[0148] - ARQ function (Error Correction through ARQ)
[0149] - Concatenation, segmentation, and reassembly functions of RLC SDUs
[0150] - Re-segmentation function (Re-segmentation of RLC data PDUs)
[0151] - Reordering function (Reordering of RLC data PDUs)
[0152] - Duplicate detection
[0153] - Error detection function (Protocol error detection)
[0154] - RLC SDU discard function
[0155] RLC re-establishment function
[0156] In the above description, the in-sequence delivery function of the NR RLC device may refer to the function of delivering RLC SDUs received from a lower layer to an upper layer in sequence. In the case where a single RLC SDU is received divided into multiple RLC SDUs, the in-sequence delivery function of the NR RLC device may include the function of reassembling and delivering them.
[0157] The in-sequence delivery function of the NR RLC device may include a function to rearrange received RLC PDUs based on an RLC SN (sequence number) or PDCP SN (sequence number), a function to record lost RLC PDUs by rearranging the order, a function to report the status of lost RLC PDUs to the transmitting side, and a function to request retransmission of lost RLC PDUs.
[0158] The in-sequence delivery function of the NR RLC (210, 235) device may include a function to deliver only the RLC SDUs prior to the lost RLC SDU in order to the upper layer if there is a lost RLC SDU. Additionally, the in-sequence delivery function of the NR RLC device may include a function to deliver all RLC SDUs received before the timer started in order to the upper layer if a predetermined timer has expired even if there is a lost RLC SDU. Additionally, the in-sequence delivery function of the NR RLC device may include a function to deliver all RLC SDUs received up to the present in order to the upper layer if a predetermined timer has expired even if there is a lost RLC SDU.
[0159] The NR RLC (210, 235) device can process the RLC PDUs in the order they are received, regardless of the sequence number (Out of sequence delivery), and deliver them to the NR PDCP (205, 240) device.
[0160] When the NR RLC (210, 235) device receives a segment, it may receive segments that are stored in a buffer or will be received later, reconstruct them into a complete RLC PDU, and then transmit it to the NR PDCP device.
[0161] The NR RLC layer may not include a concatenation function, and the function may be performed by the NR MAC layer or replaced by the multiplexing function of the NR MAC layer.
[0162] In the above description, the out-of-sequence delivery function of the NR RLC device may refer to a function of delivering RLC SDUs received from a lower layer directly to an upper layer regardless of order. The out-of-sequence delivery function of the NR RLC device may include a function of reassembling and delivering RLC SDUs when a single RLC SDU is received divided into multiple RLC SDUs. The out-of-sequence delivery function of the NR RLC device may include a function of storing the RLC SN or PDCP SN of the received RLC PDUs, sorting the order, and recording the lost RLC PDUs.
[0163] The NR MAC (215, 230) can be connected to multiple NR RLC layer devices configured in a terminal, and the main functions of the NR MAC may include some of the following functions.
[0164] - Mapping function (Mapping between logical channels and transport channels)
[0165] - Multiplexing and demultiplexing functions (Multiplexing / demultiplexing of MAC SDUs)
[0166] - Scheduling information reporting function
[0167] - HARQ function (Error correction through HARQ (hybrid automatic repeat request))
[0168] - Priority handling between logical channels of one UE
[0169] - Priority handling between UEs by means of dynamic scheduling
[0170] - MBMS service identification function
[0171] - Transport format selection function
[0172] - Padding
[0173] The NR PHY layer (220, 225) can perform the operation of channel coding and modulating upper layer data, creating OFDM symbols and transmitting them to the wireless channel, or demodulating OFDM symbols received through the wireless channel and channel decoding them to transmit them to the upper layer.
[0174] The frame structure of the 5G system will be explained in more detail below with reference to the drawings.
[0175] Figure 3 is a diagram illustrating the basic structure of the time-frequency domain, which is a wireless resource domain where data or control channels are transmitted in a 5G system.
[0176] The horizontal axis of FIG. 3 represents the time domain, and the vertical axis represents the frequency domain. In the time and frequency domains, the basic unit of a resource is a resource element (RE) (301), which can be defined as one OFDM (orthogonal frequency division multiplexing) symbol (302) on the time axis and one subcarrier (303) on the frequency axis. In the frequency domain (For example, 12) consecutive REs can form a resource block (RB) (304).
[0177] Figure 4 is a diagram illustrating an example of a slot structure considered in a 5G system.
[0178] FIG. 4 illustrates an example of a frame (400), subframe (401), and slot (402) structure. One frame (400) can be defined as 10ms. One subframe (401) can be defined as 1ms, and thus one frame (400) can be composed of a total of 10 subframes (401). One slot (402, 403) can be defined as 14 OFDM symbols (i.e., the number of symbols per slot ( )=14). One subframe (401) may be composed of one or more slots (402, 403), and the number of slots (402, 403) per one subframe (401) may vary depending on the setting value μ (404, 405) for the subcarrier spacing. In one example of FIG. 4, cases where μ=0 (404) and μ=1 (405) are set as the subcarrier spacing value are illustrated. When μ=0 (404), one subframe (401) may be composed of one slot (402), and when μ=1 (405), one subframe (401) may be composed of two slots (403). That is, the number of slots per one subframe ( ) may vary, and accordingly, the number of slots per frame ( ) may vary. Depending on each subcarrier spacing setting μ and It can be defined by Table 1 below.
[0179] [Table 1]
[0180]
[0181] Next, the Bandwidth Part (BWP) setting in a 5G communication system will be explained in detail with reference to Fig. 5.
[0182] Figure 5 is a diagram illustrating an example of a configuration for a bandwidth portion in a 5G communication system.
[0183] FIG. 5 illustrates an example in which the terminal bandwidth (UE bandwidth) (500) is configured into two bandwidth portions, namely Bandwidth portion #1 (BWP#1) (501) and Bandwidth portion #2 (BWP#2) (502). The base station may configure one or more bandwidth portions for the terminal, and for each bandwidth portion, it may configure information such as that shown in Table 2 below, for example. The BWP below may be referred to as BWP configuration information.
[0184] [Table 2]
[0185]
[0186] Of course, the above examples are not limited, and various parameters related to bandwidth portions may be configured for the terminal in addition to the above configuration information. The above information may be transmitted from the base station to the terminal via upper-layer signaling, for example, RRC signaling. At least one of the configured bandwidth portions may be activated. Whether a configured bandwidth portion is activated may be transmitted semi-statically from the base station to the terminal via RRC signaling or dynamically via DCI (downlink control information).
[0187] According to some embodiments, prior to the RRC connection, the terminal may receive an initial bandwidth portion (initial BWP) for initial connection from the base station via a master information block (MIB). More specifically, during the initial connection phase, the terminal may receive configuration information for a core set and a search space via the MIB, through which a PDCCH can be transmitted for receiving system information required for initial connection (remaining system information; which may correspond to RMSI or system Information block 1; SIB1). The core set and search space configured via the MIB may each be considered as identity (ID) 0. The base station may notify the terminal via the MIB of configuration information, such as frequency allocation information, time allocation information, and numerology, for core set #0. Additionally, the base station may notify the terminal via the MIB of configuration information regarding the monitoring period and occasion for core set #0, i.e., configuration information for search space #0. The terminal may consider the frequency range set by the control resource set #0 obtained from the MIB as the initial bandwidth portion for initial access. In this case, the identifier (ID) of the initial bandwidth portion may be considered as 0.
[0188] The settings for the bandwidth portion supported by the above 5G can be used for various purposes.
[0189] According to some embodiments, if the bandwidth supported by the terminal is smaller than the system bandwidth, this can be supported through the bandwidth portion setting. For example, by the base station setting the frequency position of the bandwidth portion (setting information 2) to the terminal, the terminal can transmit and receive data at a specific frequency position within the system bandwidth.
[0190] In addition, according to some embodiments, a base station may set multiple bandwidth portions for a terminal for the purpose of supporting different numerologies. For example, to support data transmission and reception using both a 15 kHz subcarrier interval and a 30 kHz subcarrier interval for a terminal, two bandwidth portions may be set to subcarrier intervals of 15 kHz and 30 kHz, respectively. Different bandwidth portions may be frequency division multiplexed, and when data transmission and reception is to be performed with a specific subcarrier interval, the bandwidth portion set to that subcarrier interval may be activated.
[0191] In addition, according to some embodiments, a base station may set a bandwidth portion having different bandwidth sizes for the purpose of reducing the power consumption of the terminal. For example, if the terminal supports a very large bandwidth, such as 100 MHz, and always transmits and receives data using that bandwidth, very large power consumption may occur. In particular, in a situation where there is no traffic, performing monitoring of an unnecessary downlink control channel using a large bandwidth of 100 MHz may be very inefficient in terms of power consumption. To reduce the power consumption of the terminal, the base station may set a bandwidth portion of a relatively small bandwidth, such as 20 MHz, for the terminal. In a situation where there is no traffic, the terminal can perform monitoring operations in the 20 MHz bandwidth portion, and when data is generated, it can transmit and receive data using the 100 MHz bandwidth portion according to the instructions of the base station.
[0192] Regarding the method of configuring the bandwidth part, terminals prior to RRC connection can receive configuration information for the initial bandwidth part via the MIB during the initial connection phase. More specifically, the terminal can receive a CORESET for a downlink control channel through which a DCI scheduling SIBs can be transmitted from the MIB of the PBCH (physical broadcast channel). The bandwidth of the CORESET configured by the MIB can be considered as the initial bandwidth part, and through the configured initial bandwidth part, the terminal can receive the PDSCH through which SIBs are transmitted. In addition to receiving SIBs, the initial bandwidth part may also be utilized for other system information (OSI), paging, and random access.
[0193] FIG. 6 is a drawing for explaining a carrier aggregation (CA) according to one embodiment of the present disclosure.
[0194] Referring to Fig. 6, when CA is configured (600), PCell (primary cell) and SCell (secondary cell) can be configured in the terminal.
[0195] PCell is included in the PCC (primary component carrier) and can provide RRC connection establishment / re-establishment, measurement, mobility procedures, random access procedures and selection, system information acquisition, initial random access, security key change and non-access stratum (NAS) functions.
[0196] Since the terminal performs system information monitoring through the PCell, the PCell is not deactivated, and in the UL, the PCC is carried via the PUCCH (physical uplink control channel) for the transmission of control information. Additionally, only one RRC can be connected between the terminal and the PCell, and PDCCH / PDSCH / PUSCH (physical uplink shared channel) / PUCCH transmission is possible. Furthermore, in a secondary cell group, the PSCell (spcell of a secondary cell group) can be configured and operated as the PCell. The operations for the PCell described below can also be performed by the PSCell.
[0197] Up to a total of 31 SCells can be added, and SCells can be configured via RRC messages (e.g., dedicated signaling) when additional radio resources are required. RRC messages may include the physical cell ID for each cell and the DL carrier frequency (absolute radio frequency channel number: ARFCN). PDCCH / PDSCH / PUSCH transmission is possible through SCells. Dynamic activation and deactivation procedures for SCells are supported via the MAC layer to conserve the UE's battery.
[0198] Cross-carrier scheduling may mean assigning at least one of all L1 control channels or L2 control channels (e.g., PDCCH) for at least one other component carrier (CC) to a single CC. A carrier indicator field (CIF) may be used to transmit data information from another CC through the PDCCH of one CC.
[0199] Resources for data transmission of said CC (PDSCH, PUSCH) or resources for data transmission of another CC (PDSCH, PUSCH) can be allocated through control information transmitted via the PDCCH of one CC.
[0200] With the application of cross-carrier scheduling, n-bit CIF is added to the DCI format, and the bit size may vary depending on the upper layer settings or the DCI format, and the position of the CIF within the DCI format may be fixed.
[0201] FIG. 7 is a diagram illustrating an example of a cross-carrier scheduling method according to one embodiment of the present disclosure.
[0202] Referring to 710 in Fig. 7, PDSCH or PUSCH for two CCs can be scheduled through PDCCH (701) of one CC.
[0203] In addition, referring to 720 in Fig. 7, when a total of 4 CCs are set, the PDSCH or PUSCH of each CC can be scheduled using the PDCCH (721, 723) of two CCs.
[0204] Each CC can be mapped to a CI (carrier indicator) value for CIF application, and this can be transmitted from the base station to the terminal via a dedicated RRC signal with UE-specific settings.
[0205] Each PDSCH / PUSCH CC can be scheduled from a single DL CC. Therefore, for each PDSCH / PUSCH CC, the UE only needs to monitor the PDCCH from the said DL CC. The terminal can obtain PUSCH scheduling information from the linked UL carrier by monitoring the PDCCH from the said DL CC. The terminal can obtain PDSCH scheduling information from the linked DL carrier by monitoring the PDCCH from the said DL CC.
[0206] FIG. 8 is a diagram illustrating an example of setting a control area (CORESET) of a downlink control channel in a wireless communication system according to one embodiment of the present disclosure.
[0207] Referring to FIG. 8, FIG. 8 illustrates an example in which two control areas (control area #1 (CORESET #1) (801), control area #2 (CORESET #2) (802)) are set within a single slot (820) in the frequency axis and within a terminal bandwidth portion (810) in the time axis. The control areas (801, 802) can be set in a specific frequency resource (803) within the entire terminal bandwidth portion (810) in the frequency axis. The control areas (801, 802) can be set with one or more OFDM symbols in the time axis, which can be defined as the control resource set duration (804). In the example of FIG. 8, control area #1 (801) is set with a control resource set duration of two symbols, and control area #2 (802) is set with a control resource set duration of one symbol.
[0208] The control domain in 5G described above can be configured by a base station to a terminal through upper-layer signaling (e.g., system information, MIB, RRC signaling). Configuring a control domain to a terminal means providing the terminal with information such as a control domain identifier, the frequency location of the control domain, and the symbol length of the control domain. For example, the information in Table 3 may be included.
[0209] [Table 3]
[0210]
[0211]
[0212] The number of CCEs required to transmit a PDCCH can be 1, 2, 4, 8, or 16 depending on the aggregation level (AL), and different numbers of CCEs can be used to implement link adaptation for the downlink control channel. For example, when AL=L, one downlink control channel can be transmitted through L CCEs. The terminal must detect the signal (blind decoding) without knowing information about the downlink control channel, and a search space representing a set of CCEs is defined for blind decoding. The search space is a set of downlink control channel candidates consisting of CCEs that the terminal must attempt to decode at a given aggregation level; since there are various aggregation levels that form a group of 1, 2, 4, 8, or 16 CCEs, the terminal may have multiple search spaces. A search space set can be defined as a set of search spaces at all configured aggregation levels.
[0213] Search spaces can be classified into common search spaces and UE-specific search spaces. A certain group of terminals or all terminals may examine the common search space of the PDCCH to receive cell-common control information, such as dynamic scheduling or paging messages regarding system information. For example, PDSCH scheduling allocation information for the transmission of SIBs containing cell operator information can be received by examining the common search space of the PDCCH. In the case of the common search space, since a certain group of terminals or all terminals must receive the PDCCH, it can be defined as a pre-arranged set of CCEs. Scheduling allocation information for a UE-specific PDSCH or PUSCH can be received by examining the UE-specific search space of the PDCCH. The UE-specific search space can be defined specifically as a function of the terminal's identity and various system parameters.
[0214] In 5G, parameters for the search space for a PDCCH can be configured from the base station to the terminal via upper layer signaling (e.g., SIB, MIB, RRC signaling). For example, the base station may configure the terminal the number of PDCCH candidates at each aggregation level L, the monitoring period for the search space, the occasion for monitoring in slot-symbol units for the search space, the search space type (common search space or terminal-specific search space), the combination of the DCI format and RNTI (radio network temporary identifier) to be monitored in the search space, and the control resource set index to be monitored in the search space. For example, parameters for the search space for a PDCCH may include at least some of the information such as that shown in Table 4 below.
[0215] [Table 4]
[0216]
[0217]
[0218]
[0219] A base station may set one or more sets of search spaces for a terminal. According to some embodiments, a base station may set search space set 1 and search space set 2 for a terminal. In search space set 1, the terminal may be configured to monitor DCI format A scrambled with X-RNTI in a common search space, and in search space set 2, the terminal may be configured to monitor DCI format B scrambled with Y-RNTI in a terminal-specific search space.
[0220] According to the configuration information, one or more sets of search spaces may exist in a common search space or a terminal-specific search space. For example, Search Space Set #1 and Search Space Set #2 may be configured as a common search space, and Search Space Set #3 and Search Space Set #4 may be configured as a terminal-specific search space.
[0221] In the common search space, the following combinations of DCI formats and RNTI can be monitored. Of course, they are not limited to the examples below.
[0222] DCI format 0_0 / 1_0 with CRC (cyclic redundancy check) scrambled by C-RNTI, CS-RNTI, SP-CSI-RNTI, RA-RNTI, TC-RNTI, P-RNTI, SI-RNTI
[0223] DCI format 2_0 with CRC scrambled by SFI-RNTI
[0224] DCI format 2_1 with CRC scrambled by INT-RNTI
[0225] DCI format 2_2 with CRC scrambled by TPC-PUSCH-RNTI, TPC-PUCCH-RNTI
[0226] DCI format 2_3 with CRC scrambled by TPC-SRS-RNTI
[0227] In terminal-specific search spaces, the following combinations of DCI formats and RNTI can be monitored. Of course, they are not limited to the examples below.
[0228] DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI
[0229] DCI format 1_0 / 1_1 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI
[0230] The specified RNTIs may follow the definitions and uses below.
[0231] C-RNTI (Cell RNTI): Used for terminal-specific PDSCH scheduling
[0232] TC-RNTI (Temporary Cell RNTI): Used for terminal-specific PDSCH scheduling
[0233] CS-RNTI (Configured Scheduling RNTI): Used for semi-statically configured terminal-specific PDSCH scheduling.
[0234] RA-RNTI (Random Access RNTI): Used for PDSCH scheduling during the random access phase
[0235] P-RNTI (Paging RNTI): Used for PDSCH scheduling where paging is transmitted.
[0236] SI-RNTI (System Information RNTI): Used for PDSCH scheduling where system information is transmitted.
[0237] INT-RNTI (Interruption RNTI): Used to indicate whether PDSCH is pucturing.
[0238] TPC-PUSCH-RNTI (Transmit Power Control for PUSCH RNTI): Used to instruct power control commands to the PUSCH
[0239] TPC-PUCCH-RNTI (Transmit Power Control for PUCCH RNTI): Used to instruct power control commands to the PUCCH
[0240] TPC-SRS-RNTI (Transmit Power Control for SRS RNTI): Used to instruct power regulation commands to the SRS
[0241] In 5G, the search space of aggregation level L in the control resource set p and search space set s can be expressed as Equation 1 below.
[0242] [Mathematical Formula 1]
[0243]
[0244] - L: Lamination Level
[0245] - : Carrier Index
[0246] - : Total number of CCEs existing within control domain p
[0247] - : Slot Index
[0248] - : Number of PDCCH candidates at assembly level L
[0249] - : PDCCH candidate index of aggregation level L
[0250] - i = 0, … , L -1
[0251] - , , D=65537
[0252] - : Terminal identifier
[0253] The value may be 0 for the common search space.
[0254] In the case of a terminal-specific search space, the value may correspond to a value that changes according to the terminal's identity (C-RNTI or ID set by the base station for the terminal) and the time index.
[0255] Therefore, the terminal can monitor the PDCCH in a control area set from the base station and transmit and receive data based on the received control information.
[0256] In a 5G system, scheduling information for uplink data (or physical uplink data channel (PUSCH)) or downlink data (or physical downlink data channel (PDSCH)) can be transmitted from the base station to the terminal via DCI. The terminal can monitor the fallback DCI format and the non-fallback DCI format for PUSCH or PDSCH. The fallback DCI format may consist of fixed fields selected between the base station and the terminal, and the non-fallback DCI format may include configurable fields.
[0257] DCI can be transmitted through the PDCCH, a physical downlink control channel, after undergoing channel coding and modulation processes. A CRC is added to the DCI message payload, and the CRC can be scrambled based on the RNTI corresponding to the terminal's identity. Different RNTIs may be used depending on the purpose of the DCI message, such as UE-specific data transmission, power control commands, or random access responses. In other words, the RNTI is not explicitly transmitted but is included in the CRC calculation process. Upon receiving a DCI message transmitted over the PDCCH, the terminal checks the CRC using the assigned RNTI; if the CRC check result is correct, the terminal knows that the message has been transmitted to it.
[0258] For example, a DCI scheduling a PDSCH for system information (SI) can be scrambled to SI-RNTI. A DCI scheduling a PDSCH for a random access response (RAR) message can be scrambled to RA-RNTI. A DCI scheduling a PDSCH for a paging message can be scrambled to P-RNTI. A DCI notifying a slot format indicator (SFI) can be scrambled to SFI-RNTI. A DCI notifying a transmit power control (TPC) can be scrambled to TPC-RNTI. A DCI scheduling a terminal-specific PDSCH or PUSCH can be scrambled to C-RNTI (cell RNTI).
[0259] Meanwhile, NR can provide various forms of DCI formats as shown in Table 5 below to efficiently receive control information from the terminal.
[0260] [Table 5]
[0261]
[0262] For example, a base station may use DCI format 1_0, DCI format 1_1, or DCI format 1_2 to schedule a PDSCH for a single cell to a terminal. As another example, a base station may use DCI format 0_0, DCI format 0_1, or DCI format 0_2 to schedule a PUSCH for a single cell to a terminal. As yet another example, a base station may use DCI format 0_1 to indicate downlink feedback information for a configured grant PUSCH.
[0263] When DCI format 1_0 is transmitted with a CRC scrambled by C-RNTI, CS-RNTI, MCS-C-RNTI, or new-RNTI, it may include, for example, at least information such as that in Table 6:
[0264] [Table 6]
[0265]
[0266]
[0267] When DCI format 1_1 is transmitted with a CRC scrambled by C-RNTI (cell radio network temporary identifier), CS-RNTI (configured scheduling RNTI), MCS-C-RNTI, or new-RNTI, it may include, for example, at least information such as that in Table 7.
[0268] [Table 7]
[0269]
[0270]
[0271] When DCI format 1_2 is transmitted with a CRC scrambled by C-RNTI (cell radio network temporary identifier), CS-RNTI (configured scheduling RNTI), MCS-C-RNTI, or new-RNTI, it may include, for example, at least information such as that in Table 8.
[0272] [Table 8]
[0273]
[0274]
[0275] The maximum number of different sizes of DCIs that a terminal can receive per slot in the cell is 4. The maximum number of different sizes of DCIs scrambled with C-RNTI that a terminal can receive per slot in the cell is 3.
[0276] The base station can set time-domain resource allocation information for the downlink data channel (PDSCH) and uplink data channel (PUSCH) for the terminal (e.g., information configured in the form of a table) through upper-layer signaling (e.g., RRC signaling). For PDSCH, the base station can set resource allocation information consisting of a maximum of maxNrofDL-Allocations = 16 entries (e.g., information configured in the form of a table), and for PUSCH, resource allocation information consisting of a maximum of maxNrofUL-Allocations = 16 entries (e.g., information configured in the form of a table). Time domain resource allocation information may include, for example, PDCCH-to-PDSCH slot timing (corresponding to a slot-unit time interval between the time when the PDCCH is received and the time when the PDSCH scheduled by the received PDCCH is transmitted, denoted as K0) or PDCCH-to-PUSCH slot timing (corresponding to a slot-unit time interval between the time when the PDCCH is received and the time when the PUSCH scheduled by the received PDCCH is transmitted, denoted as K2), information regarding the position and length of the starting symbol for which the PDSCH or PUSCH is scheduled within the slot, and the mapping type of the PDSCH or PUSCH. For example, information such as that shown in Table 9 or Table 10 below may be notified from the base station to the terminal.
[0277] [Table 9]
[0278]
[0279] [Table 10]
[0280]
[0281] The base station may notify the terminal of one of the entries in the table for the time domain resource allocation information via L1 signaling (e.g., DCI) (e.g., may indicate the time domain resource allocation field within the DCI). The terminal may obtain time domain resource allocation information for PDSCH or PUSCH based on the DCI received from the base station.
[0282] The following describes the frequency domain resource allocation method for data channels in a 5G communication system.
[0283] In 5G, two types, resource allocation type 0 and resource allocation type 1, are supported as methods for indicating frequency domain resource allocation information for downlink data channels (PDSCH) and uplink data channels (PUSCH).
[0284] In resource allocation type 0, RB allocation information may be notified from the base station to the terminal in the form of a bitmap for a resource block group (RBG). In this case, the RBG may be composed of a set of consecutive VRBs, and the size P of the RBG may be determined based on a value set as an upper layer parameter (rbg-Size) and the size value of the bandwidth part defined as in Table 11 below.
[0285] [Table 11] Nominal RGB size P
[0286]
[0287] The size Total number of RGBs in bandwidth part i ( ) can be defined as follows.
[0288] , where
[0289] the size of the first RBG is ,
[0290] the size of last RBG is if and P otherwise,
[0291] the size of all other RBGs is P.
[0292] Each bit of a bitmap of bit size can correspond to a respective RGB. The RGBs can be indexed in increasing order of frequency, starting from the lowest frequency position in the bandwidth part. Within the bandwidth part For the RBGs, from RBG#0 to RBG#( ) can be mapped from the MSB to the LSB of the RGB bitmap. If a specific bit value in the bitmap is 1, the terminal can determine that the RGB corresponding to that bit value has been assigned, and if a specific bit value in the bitmap is 0, the terminal can determine that the RGB corresponding to that bit value has not been assigned.
[0293] In Resource Allocation Type 1, RB allocation information may be notified from the base station to the terminal as information regarding the starting position and length of consecutively allocated VRBs. In this case, interleaving or non-interleaving may be additionally applied to the consecutively allocated VRBs. The resource allocation field of Resource Allocation Type 1 may consist of a resource indication value (RIV), and the RIV is the starting point of the VRB ( ) and the length of consecutively allocated RB ( It can be composed of. More specifically, The RIV within the bandwidth part of the size can be defined as follows.
[0294]
[0295] FIG. 9 is a diagram illustrating an example of downlink data channel processing in a wireless communication system according to one embodiment of the present disclosure.
[0296] A scrambling process can be performed for one codeword or for each of two codewords (901). Length A sequence of codewords q containing scrambling sequence obtained through initialization as in mathematical equation 3 A scrambled sequence using the process as in Equation 2 You can obtain. The value is set through the upper layer parameter, or otherwise the cell ID value It can be determined as, and n RNTI may refer to an RNTI associated with PDSCH transmission.
[0297] [Mathematical Formula 2]
[0298]
[0299] [Mathematical Formula 3]
[0300]
[0301] A sequence of scrambled beats and using one of the various modulation schemes supported by the wireless communication system A modulation symbol sequence having a length (902) can be generated.
[0302] v layers, for each layer Each modulation symbol can be mapped (903), and if this is expressed It is the same as. The relationship between the number of layers, the number of codewords, and the codeword-layer mapping is as shown in Table 12.
[0303] [Table 12]
[0304]
[0305] The modulation symbols mapped to the layer can be mapped to the antenna port as shown in Equation 4. This can be determined by the information included in the DCI format (904).
[0306] [Mathematical Formula 4]
[0307]
[0308] After completing the above process Symbols can be mapped to REs within VRBs allocated for transmission that satisfy conditions for use in PDSCH transmission (e.g., cannot be mapped to DM-RS resources, etc.) (905).
[0309] VRBs that have completed the above process can be mapped to PRBs via an interleaving or non-interleaving mapping method (906). The mapping method can be indicated through the VRB-to-PRB mapping field in the DCI, and if there is no indication of the mapping method, it may mean a non-interleaving mapping method.
[0310] When a non-interleaving mapping method is used, VRB n can be mapped to PRB n, except in specific cases. For example, the aforementioned specific case is when VRB n of a PDSCH scheduled using DCI format 1_0 through the common seek space is PRB ( This may include cases where the above DCI is mapped to the first PRB of the transmitted CORESET.
[0311] When the interleaving mapping method is used, the RBs within the BWP It can be divided into RB bundles, and the RB bundles can be mapped using the method shown in Table 13.
[0312] RBs within BWP One example of dividing into RB bundles could be as follows. Starting point Inside a BWP having The set of RBs is It is divided into RB bundles, and the said RB bundles can be indexed in increasing order. Here, Li refers to the bundle size in BWP i, which can be transmitted to the terminal by the upper layer parameter vrb-ToPRB-Interleaver. And, RB bundle 0 is Consists of RBs, and RB bundle Is If satisfied It consists of n RBs and otherwise can be composed of Li RBs. And the remaining RB bundles can be composed of Li RBs.
[0313] [Table 13]
[0314]
[0315] According to one embodiment of the present disclosure, in a 5G NR system, an MCS index for PDSCH, i.e., a modulation order (or method) Qm and a target code rate R, can be determined through the following process.
[0316] [MCS Index Table Determination Method]
[0317] For a PDSCH scheduled via a PDCCH (PDCCH with DCI format 1_0, format 1_1, or format 1_2 with CRC scrambled by C-RNTI, MCS-C-RNTI, TC-RNTI, CS-RNTI, SI-RNTI, RA-RNTI, MSGB-RNTI, or P-RNTI) containing a DCI (e.g., DCI format 1_0, DCI format 1_1, or DCI format 1_2) with a CRC scrambled by C-RNTI, MCS-C-RNTI, TC-RNTI, CS-RNTI, SI-RNTI, RA-RNTI, MSGB-RNTI, or P-RNTI, or for a PDSCH scheduled using a PDSCH configuration SPS-Config (or SPS configuration) provided by an upper layer without a corresponding PDCCH transmission,
[0318] (a) If the higher layer parameter mcs-Table given by PDSCH-Config is set to 'qam256', and the PDSCH is scheduled by a PDCCH with DCI format 1_1 with CRC scrambled by C-RNTI, the terminal can use the MCS index IMCS value of [Table 15] to determine the modulation order Qm and the target code rate R.
[0319] (b) If the condition of (a) is not satisfied, and the UE is not configured with MCS-C-RNTI, and the higher layer parameter mcs-Table given by PDSCH-Config is set to 'qam64LowSE', and the PDSCH is scheduled by a PDCCH with a DCI format other than DCI format 1_2 in a UE-specific search space with CRC scrambled by C-RNTI, the UE can use the MCS index IMCS value of [Table 16] to determine the modulation order Qm and the target code rate R.
[0320] (c) If the conditions of (a) and (b) are not satisfied, and the UE is configured with MCS-C-RNTI, and the PDSCH is scheduled by a PDCCH with CRC scrambled by MCS-C-RNTI, the UE can use the MCS index IMCS value from [Table 16] to determine the modulation order Qm and the target code rate R.
[0321] (d) if the conditions of (a), (b), and (c) are not satisfied, and also the UE is not configured with the higher layer parameter mcs-Table given by SPS-Config, and the higher layer parameter mcs-Table given by PDSCH-Config is set to 'qam256',
[0322] (d-1) If the PDSCH is scheduled by a PDCCH with DCI format 1_1 with CRC scrambled by CS-RNTI, or,
[0323] (d-2) When PDSCH is scheduled without a corresponding PDCCH transmission using SPS-Config,
[0324] The terminal can use the MCS index IMCS value from [Table 15] to determine the modulation order Qm and target code rate R.
[0325] (e) If the conditions of (a), (b), (c), and (d) are not satisfied, and the UE is configured with the higher layer parameter mcs-Table given by SPS-Config set to 'qam64LowSE',
[0326] (e-1) If the PDSCH is scheduled by a PDCCH with CRC scrambled by CS-RNTI or,
[0327] (e-2) If the PDSCH is scheduled without corresponding PDCCH transmission using SPS-Config,
[0328] The UE can use the MCS index IMCS value from [Table 16] to determine the modulation order Qm and target code rate R.
[0329] (f) When the conditions of (a), (b), (c), (d), and (e) are not met, the UE can use the MCS index IMCS value from [Table 14] to determine the modulation order Qm and the target code rate R.
[0330] [Table 14]
[0331]
[0332]
[0333] [Table 15]
[0334]
[0335]
[0336] [Table 16]
[0337]
[0338]
[0339] FIG. 10 is a diagram illustrating an example of a method for obtaining the transport block size (TBS) in a wireless communication system according to one embodiment of the present disclosure.
[0340] The terminal first determines the number of REs (N) within the slot. RE ) can be obtained (determined, or calculated) (1001). The terminal is the number of REs allocated to the PDSCH mapping in one PRB within the allocated resources. Can obtain (calculate). Is It can be calculated as. Here, is 12, and can represent the number of OFDM symbols assigned to PDSCH. is the number of REs of DMRS of the same CDM group within a PRB. is the number of REs occupied by the overhead within the PRB as long as it is set to the upper signaling, and can be set to one of 0, 6, 12, or 18 (it can be set to 0 if it is not set to the upper signaling).
[0341] And, the total number of REs allocated to PDSCH can be calculated. Is It is calculated based on, represents the number of PRBs allocated to the terminal. The value can be calculated as above. Or, Information including all possible cases that can be set to the value of (e.g., may be organized in the form of at least one table) is stored, and Through at least one parameter value, from the above-mentioned stored information (e.g., a table) The value can be obtained.
[0342] And, the terminal is the number of temporary information bits It can obtain (calculate) (1002). For example, the number of temporary information bits N above. inf o is It can be calculated as follows. Here, R represents the coding rate and Qm represents the modulation order, and the information can be determined based on the modulation and coding scheme (MCS) information included in the control information (e.g., DCI, RRC setting information, etc.). Specifically, pre-agreed information regarding the coding rate and modulation order (e.g., MCS index tables such as Tables 14, 15, 16) may be used, and the coding rate and modulation order may be determined based on the MCS information and the pre-agreed information. v may represent the number of assigned layers. The value is calculated as above, or information including all possible cases (e.g., in the form of at least one table) is stored, and from the stored information through at least one parameter value among R, Qm, and v The value can be obtained.
[0343] The terminal acquired (calculated) The value of can be compared with the value of 3824 (1003). Depending on whether the value of is less than or greater than 3824, different methods can be used. and TBS can be obtained (calculated) (1004).
[0344] In the case of, and Through the formula can be calculated. The value is calculated as above, or information on all possible cases (e.g., at least one table) is stored, and From the stored information above through at least one parameter value among , n The value can be obtained. TBS is from Table 17 Among values not smaller than It can be determined as the value closest to .
[0345] [Table 17]
[0346]
[0347] In the case of, and Through the formula can be calculated. The value is calculated as above, or information on all possible cases (e.g., at least one table) is stored, and A value can be obtained from the stored table above through at least one parameter value among , n. TBS is It can be determined through the value and the pseudo code included in Table 18, or other forms of pseudo code that produce the same result. Alternatively, the above TBS stores information on all possible cases (e.g., at least one table), and R, The TBS value can be obtained from the stored information through at least one parameter value among C.
[0348] [Table 18]
[0349]
[0350] The maximum data rate supported by the terminal in the NR system can be determined through Equation 6.
[0351] [Mathematical Formula 6]
[0352]
[0353] In mathematical equation 6, J is the number of carriers grouped by frequency aggregation, and Rmax = 948 / 1024, is the maximum number of layers, is the maximum modulation order, is the scaling index, can mean the subcarrier spacing. The terminal You can report by setting it to one of the values 1, 0.8, 0.75, or 0.4, and It can be given as shown in Table 19.
[0354] [Table 19]
[0355]
[0356] is the average OFDM symbol length, and Is It can be calculated as, is the maximum number of RBs in BW(j). is an overhead value, which can be given as 0.14 for the downlink and 0.18 for the uplink of FR1 (band below 6 GHz), and as 0.08 for the downlink and 0.10 for the uplink of FR2 (band above 6 GHz). For example, through Equation 6, the maximum data rate in the downlink of a cell with a frequency bandwidth of 100 MHz at a subcarrier spacing of 30 kHz can be as shown in Table 20 below.
[0357] [Table 20]
[0358]
[0359] Meanwhile, the actual data rate, which represents the actual data transmission efficiency, can be the value obtained by dividing the amount of transmitted data by the data transmission time. That is, in the case of 1 TB transmission, it can be the value obtained by dividing the sum of 2 TBS or 2 TBS in the case of 2 transmissions by the length of the transmission time interval (TTI). The maximum actual downlink data rate in a cell with a 30 kHz subcarrier spacing and a 100 MHz frequency bandwidth can be determined according to the number of allocated PDSCH symbols as shown in Table 21 below.
[0360] [Table 21]
[0361]
[0362] By referring to the maximum data rate supported by the terminal as shown in Table 20 and the actual data rate according to the allocated TBS as shown in Table 21, it can be seen that there are cases where the actual data rate is greater than the maximum data rate supported by the terminal depending on the scheduling information.
[0363] In wireless communication systems and NR systems, the maximum frequency band, maximum modulation order, and maximum number of layers supported by the terminal can be used to determine (calculate, obtain) the terminal's supported data rate between the base station and the terminal. However, the terminal's supported data rate may differ from the actual data rate calculated based on TBS and TTI, and in some cases, the base station may transmit data to the terminal that has a TBS greater than the terminal's supported data rate.
[0364] According to one embodiment of the present disclosure, a base station may configure configuration information for an SPS to a terminal via upper layer signaling (e.g., RRC signaling). For example, the configuration information may be transmitted to the terminal via an SPS-Config IE. The configuration information may include, for example, at least information such as that in Table 22. Depending on the capability of the terminal, the base station may configure at least one SPS using the configuration information such as that in Table 22. If multiple SPS are configured, the multiple SPS may be distinguished by the sps-ConfigIndex of Table 22. According to the present disclosure, the sps-ConfigIndex may be referred to as the SPS index. SPS configuration (or SPS configuration information) may be performed per BWP of a serving cell, and multiple SPS configurations may be simultaneously activated within the same BWP.
[0365] [Table 22]
[0366]
[0367]
[0368] According to one embodiment of the present disclosure, a base station may configure configuration information for a ConfiguredGrant to a terminal via upper layer signaling (e.g., RRC signaling). For example, the configuration information may be transmitted to the terminal via ConfiguredGrantConfig IE. The configuration information may configure at least one ConfiguredGrant using, for example, configuration information such as that in Table 23. If multiple ConfiguredGrants are configured, the multiple ConfiguredGrants may be distinguished by the configuredGrantConfigIndex and / or configuredGrantConfigIndexMAC of Table 23. According to the present disclosure, the configuredGrantConfigIndex and / or configuredGrantConfigIndexMAC may be referred to as a ConfiguredGrant. ConfiguredGrant configuration (or ConfiguredGrant configuration information) may be performed per BWP of a serving cell, and multiple ConfiguredGrant configurations may be simultaneously activated within the same BWP. There are two types of the above ConfiguredGrant: type 1 allows the terminal to transmit data through the resources configured via Table 23 using only RRC settings, and type 2 allows the terminal to transmit data only when the terminal receives a signal activating the ConfiguredGrant configured through RRC settings and control signals (e.g., DCI or MAC CE).
[0369] [Table 23]
[0370]
[0371]
[0372]
[0373]
[0374]
[0375] A base station may instruct a terminal to activate or release at least one of the configured SPS or ConfiguredGrant (type2) through a control signal (e.g., DCI, or MAC CE). For example, the base station may instruct the activation or release of the SPS or ConfiguredGrant (type2) by setting at least one specific field within the DCI to a specific value, scrambling the CRC generated through the DCI into a specific RNTI, and transmitting it to the terminal via PDCCH. DCI format 1_0, 1_1, or 1_2 may be used as the DCI instructing the activation or release of the SPS, and DCI format 0_0, 0_1, or 0_2 may be used as the DCI instructing the activation or release of the ConfiguredGrant (type2). More specifically, the CRC is scrambled using CS-RNTI (provided to the terminal as an RRC setting), the value of the new data indicator (NDI) field in the DCI is set to 0, and if the DFI flag field exists, it is set to 0. If it is enabled, the PDSCH-to-HARQ_feedback timing indicator field exists and the value of the field satisfies the condition that it does not provide an inapplicable value among the values of dl-DataToUL-ACK, then the DCI can be interpreted as enabled or disabled.If there is only one SPS or ConfiguredGrant(type2) setting, if the HARQ process number field of the DCI is set to all 0s and the redundancy version field is set to all 0s, it indicates that SPS or ConfiguredGrant(type2) is enabled; if the HARQ process number field of the DCI is set to all 0s, the redundancy version field is set to all 0s, and the modulation and coding scheme field is set to all 1s; if it is FDRA type 0 or dynamicSwitch (i.e., when the resource allocation type can be changed based on the DCI), the FDRA field is set to all 0s; if it is FDRA type 1, if the FDRA field is set to all 1s, it indicates that SPS is disabled; if the HARQ process number field of the DCI is set to all 0s, the redundancy version field is set to all 0s, and the modulation and coding scheme field is set to all 1s; if it is FDRA type 2 (μ value is 1), the FDRA field is set to all 0s; and in other cases If all are set to 1, it can be interpreted as disabling ConfiguredGrant(type2).
[0376] If there are multiple SPS or ConfiguredGrant(type2) configurations, the HARQ process number field in the DCI is the above SPS-config. Alternatively, it may be interpreted as indicating sps-ConfigIndex or configuredGrantConfigIndex within the ConfiguredGrant configuration, and if the redundancy version field of the DCI is all set to 0, it may be interpreted as the activation of the SPS or ConfiguredGrant(type2) corresponding to the sps-ConfigIndex or configuredGrantConfigIndex; if the redundancy version field of the DCI is all set to 0 and the modulation and coding scheme field is all set to 1, and in the case of FDRA type 0 or dynamicSwitch, the FDRA field is all set to 0, and in the case of FDRA type 1, the FDRA field is all set to 1, it may be interpreted as the deactivation of the SPS corresponding to the sps-ConfigIndex; if the redundancy version field of the DCI is all set to 0 and the modulation and coding scheme field is all set to 1, and in the case of FDRA type 2 (μ value is 1), the FDRA field is all set to 0, and in other cases, it may be interpreted as the deactivation of the ConfiguredGrant(type2).
[0377] When the terminal receives a DCI instructing SPS deactivation, it clears the configured downlink assignment for the corresponding serving cell if one exists, and if the timeAlignmentTimer associated with the TAG containing the serving cell to which the HARQ feedback is to be transmitted is running, it can transmit an ACK for deactivation.
[0378] When the terminal receives a DCI instructing the deactivation of ConfiguredGrant, it triggers a 'configured uplink grant confirmation' and, after transmitting a MAC CE (Configured Grant Confirmation MAC CE or Multiple Entry Configured Grant Confirmation MAC CE) confirming the 'configured uplink grant deactivation', can clear the configured uplink grant(s).
[0379] When the terminal receives a DCI instructing SPS activation, it can store the downlink assignment and associated HARQ information of the corresponding serving cell as the configured downlink assignment and (re)initialize the configured downlink assignment of the corresponding serving cell.
[0380] When the terminal receives a DCI instructing the activation of ConfiguredGrant, it triggers a 'configured uplink grant confirmation', saves the uplink grant and associated HARQ information of the corresponding serving cell as the configured uplink grant, and can (re)initialize the configured uplink grant of the corresponding serving cell.
[0381] The base station can set the value of the NDI field of the DCI to 1, scramble the CRC of the DCI into CS-RNTI, and transmit it through the PDCCH to schedule a retransmission for an SPS PDSCH transmission or a ConfiguredGrant PUSCH transmission.
[0382] The base station can transmit PDSCH to a resource determined according to the above RRC settings and activation DCI signals. More specifically, the transmission slot of the Nth PDSCH can be determined as in Equation 7. The HARQ process ID associated with SPS transmission can be determined as in Equation 8 when harq-ProcID-Offset is not set, and as in Equation 9 when it is set.
[0383] [Mathematical Formula 7]
[0384]
[0385] - SFN start time slotstart time refers to the SFN and slot of the first PDSCH transmission in which the configured downlink assignment is (re)initialized, and numberOfSlotsPerFrame indicates the number of slots included in the frame.
[0386] [Mathematical Formula 8]
[0387]
[0388] - CURRENT_slot = [(SFN × numberOfSlotsPerFrame) + slot number in the frame]
[0389] - CURRENT_slot points to the slot index at the time of the first transmission of the bundle of the configured downlink assignment.
[0390] [Mathematical Formula 9]
[0391]
[0392] - CURRENT_slot = [(SFN × numberOfSlotsPerFrame) + slot number in the frame]
[0393] - CURRENT_slot points to the slot index at the time of the first transmission of the bundle of the configured downlink assignment.
[0394] The terminal can transmit PUSCH to a resource (ConfiguredGrant type 1) determined according to the above RRC settings. More specifically, the location of the Nth uplink grant can be determined as in Equation 10.
[0395] [Mathematical Formula 10]
[0396]
[0397]
[0398] The terminal can transmit PUSCH to a resource (ConfiguredGrant type 1) determined according to the RRC configuration and the enabled DCI signal. More specifically, the location of the Nth uplink grant can be determined as in Equation 11.
[0399] [Mathematical Formula 11]
[0400]
[0401] - SFN start time , slotstart time and symbolstart time refer to the SFN, slot, and symbol of the first PUSCH transmission in which the configured uplink grant is (re)initialized, and numberOfSlotsPerFrame indicates the number of slots included in the frame.
[0402] The HARQ process ID associated with the first symbol of a ConfiguredGrant UL transmission can be determined as in Equation 12 when harq-ProcID-Offset2 and cg-RetransmissionTimer are not set, and as in Equation 13 when harq-ProcID-Offset2 is set. When cg-RetransmissionTimer is set, the terminal can select one of the available HARQ process IDs among the ConfiguredGrant settings. The terminal may prioritize retransmission over initial transmission.
[0403] [Mathematical Formula 12]
[0404] HARQ Process ID = [floor(CURRENT_symbol / periodicity)] modulo nrofHARQ-Processes
[0405] - CURRENT_symbol = (SFN × numberOfSlotsPerFrame × numberOfSymbolsPerSlot + slot number in the frame × numberOfSymbolsPerSlot + symbol number in the slot)
[0406] - numberOfSlotsPerFrame represents the number of slots in a frame, and numberOfSymbolsPerSlot represents the number of symbols in a slot.
[0407] - CURRENT_symbol points to the symbol index at the time of the first transmission of the bundle of the configured uplink grant.
[0408] [Mathematical Formula 13]
[0409] HARQ Process ID = [floor(CURRENT_symbol / periodicity)] modulo nrofHARQ-Processes + harq-ProcID-Offset2
[0410] - CURRENT_symbol = (SFN × numberOfSlotsPerFrame × numberOfSymbolsPerSlot + slot number in the frame × numberOfSymbolsPerSlot + symbol number in the slot)
[0411] - numberOfSlotsPerFrame represents the number of slots in a frame, and numberOfSymbolsPerSlot represents the number of symbols in a slot.
[0412] - CURRENT_symbol points to the symbol index at the time of the first transmission of the bundle of the configured uplink grant.
[0413] According to one embodiment of the present disclosure, DCI format 0_1 may be configured to include a DFI (downlink feedback information) field (1 bit). When the CRC of DCI format 0_1, in which the value of the DFI field is 1, is scrambled with CS-RNTI, the DCI format 0_1 is interpreted to include a DCI format identifier (1 bit), a carrier indicator (0 or 3 bits), a DFI flag (1 bit if set), a HARQ-ACK bitmap (16 bits), and a TPC command (2 bits) for a scheduled PUSCH, and the remaining fields may all be filled with 0. The HARQ process index may be mapped in order from MSB to LSB of the HARQ-ACK bitmap, and a value of 1 may represent ACK and 0 may represent NACK. If the value of the above DFI field is 0, the above DCI may be used for other purposes (PUSCH scheduling or (de)enabled of ConfiguredGrant). The above HARQ-ACK bitmap corresponds to all HARQ process(s) of the serving cell, and the above carrier indicator may indicate which serving cell it is.
[0414] For a PUSCH transmission configured by ConfiguredGrant, if the reception time of the first symbol of the PDCCH transmitted by the DCI format 0_1 is later than the number of symbols given by cg-minDFI-Delay (configured through RRC settings such as Table 23) from the last symbol of the PUSCH transmission or any one last symbol of the PUSCH repeated transmission, the HARQ-ACK information of the corresponding (corresponding to the PUSCH transmission) HARQ process index included in the DCI format 0_1 may be valid.
[0415] For a PUSCH transmission scheduled by the DCI format, if the reception time of the first symbol of the PDCCH transmitted by the DCI format 0_1 is later than the number of symbols given by cg-minDFI-Delay (set via RRC settings such as Table 23) from the last symbol of the PUSCH transmission, the HARQ-ACK information of the corresponding (corresponding to the PUSCH transmission) HARQ process index included in the DCI format 0_1 may be valid.
[0416] In the case of PUSCH transmission in multiple slots scheduled by the DCI format, the criteria for determining whether the HARQ-ACK information is valid may differ depending on whether the HARQ-ACK information of the corresponding (corresponding to the PUSCH transmission) HARQ process index included in the DCI format 0_1 is ACK or NACK. If the HARQ-ACK information is ACK, the HARQ-ACK information may be determined to be valid if the reception time of the first symbol of the PDCCH transmitted by the DCI format 0_1 is located after the number of symbols given by cg-minDFI-Delay (set through RRC settings such as Table 23) from the last symbol of the PUSCH transmission in the first slot among the PUSCH transmissions in multiple slots. If the HARQ-ACK information is NACK, the reception time of the first symbol of the PDCCH in which the DCI format 0_1 is transmitted is later than the number of symbols given by cg-minDFI-Delay (set through RRC settings such as Table 23) from the last symbol of the PUSCH transmission in the last slot among the PUSCH transmissions in multiple slots, the HARQ-ACK information can be determined to be valid.
[0417] The terminal may not expect that the cg-minDFI-Delay values set for each of the multiple ConfiguredGrants included in a single BWP are different.
[0418] While additional coverage expansion technologies have been introduced for 5G mobile communication services compared to LTE services, the Time Division Duplex (TDD) system, which is generally suitable for services with a high proportion of downlink traffic, can be utilized in actual 5G mobile communication services. Furthermore, as the center frequency is raised to expand the frequency band, coverage between base stations and terminals decreases; therefore, coverage enhancement is a core requirement for 5G mobile communication services. In particular, to support services where the transmission power of the terminal is generally lower than that of the base station and the proportion of downlink traffic is high, and because the ratio of downlink traffic in the time domain is higher than that of uplink, enhancing uplink channel coverage is a key requirement for 5G mobile communication services. Physical methods to improve the coverage of the uplink channel between the base station and the terminal include increasing the time resources of the uplink channel, lowering the center frequency, or increasing the transmission power of the terminal. However, changing the frequency may be subject to limitations because frequency bands are determined by each network operator. In addition, since the maximum transmission power of the terminal is regulated to reduce interference, there may be limitations on increasing the maximum transmission power of the terminal to improve coverage.
[0419] Therefore, to improve the coverage of base stations and terminals, uplink and downlink resources in the time domain can be divided according to the traffic proportions of uplink and downlink as in a TDD system, and uplink and downlink resources can also be divided in the frequency domain as in a FDD (frequency division duplex) system. In one embodiment, a system capable of flexibly dividing uplink and downlink resources in the time domain and the frequency domain may be referred to as an XDD (cross division duplex) system, a Flexible TDD system, a Hybrid TDD system, a TDD-FDD system, a Hybrid TDD-FDD system, etc., and for convenience of explanation, this disclosure describes it as an XDD system. According to one embodiment, in XDD, X may mean time or frequency.
[0420] FIG. 11a is a diagram illustrating the uplink-downlink resource configuration of an XDD system that flexibly divides uplink and downlink resources in the time domain and frequency domain according to one embodiment of the present disclosure.
[0421] Referring to FIG. 11a, from the perspective of a base station, the uplink-downlink configuration (1100a) of the overall XDD system allows for the flexible allocation of resources for each symbol or slot (1102a) according to the traffic proportion of the uplink and downlink over the entire frequency band (1101a). However, this is merely an example, and the unit for resource allocation is not limited to a symbol or slot (1102a), and resources may be flexibly allocated according to units such as mini-slots. At this time, a guard band (1104a) may be allocated between the frequency bands of the downlink resource (1103a) and the uplink resource (1105a). This guard band (1104a) may be allocated as a measure to reduce interference applied to the uplink channel or signal reception caused by out-of-band emission that occurs when a base station transmits a downlink channel or signal from the downlink resource (1103a). At this time, for example, terminal 1 (1110a) and terminal 2 (1120a), in which downlink traffic is generally greater than uplink traffic due to the base station settings, can be allocated a downlink and uplink resource ratio of 4:1 in the time domain. At the same time, terminal 3 (1130a), which operates at the cell edge and has insufficient uplink coverage, can be allocated only uplink resources in a specific time interval due to the base station settings. Additionally, terminal 4 (1140a), which operates at the cell edge and has insufficient uplink coverage but has relatively large amounts of downlink and uplink traffic, can be allocated a large amount of uplink resources in the time domain for uplink coverage and a large amount of downlink resources in the frequency band. As described in the example above, there is an advantage that more downlink resources can be allocated in the time domain to terminals with relatively large downlink traffic operating at the cell center, and more uplink resources can be allocated in the time domain to terminals with insufficient uplink coverage operating at the cell edge.
[0422] FIG. 11b is a diagram illustrating an example of an uplink-downlink resource configuration of a full-duplex communication system in which uplink and downlink resources are flexibly divided in the time domain and the frequency domain according to one embodiment of the present disclosure.
[0423] According to one example illustrated in FIG. 11b, all or part of the downlink resource (1100b) and the uplink resource (1101b) may be configured to overlap in the time and frequency domains. Downlink transmission from a base station to a terminal may be performed in the area configured as the downlink resource (1100b), and uplink transmission from a terminal to a base station may be performed in the area configured as the uplink resource (1101b).
[0424] In one example of FIG. 11b, the entire downlink resource (1110b) and the uplink resource (1111b) may be configured to overlap in the time resource corresponding to the symbol or slot (1102b) and the frequency resource corresponding to the bandwidth (1103b). At this time, since the downlink resource (1110b) and the uplink resource (1111b) overlap in time and frequency, downlink and uplink transmission and reception of the base station or terminal may occur simultaneously in the same time and frequency resources.
[0425] In another example of FIG. 11b, a portion of the downlink resource (1120b) and the uplink resource (1121b) may be configured to overlap in the time resource corresponding to a symbol or slot and the frequency resource corresponding to the bandwidth (1103b). In this case, downlink and uplink transmission and reception of the base station or terminal may occur simultaneously in the portion where the downlink resource (1120b) and the uplink resource (1121b) overlap.
[0426] In another example of FIG. 11b, the downlink resource (1130b) and the uplink resource (1131b) can be configured so as not to overlap in the time resource corresponding to the symbol or slot and the frequency resource corresponding to the bandwidth (1103b).
[0427] FIG. 11c is a drawing illustrating a transmission and reception structure for a duplex method according to one embodiment of the present disclosure.
[0428] The transceiver structure illustrated in FIG. 11c can be used in a base station device or a terminal device. According to the transceiver structure illustrated in FIG. 11c, the transmitter may be composed of blocks such as a transmit baseband block (Tx Baseband, 1110c), a digital pre-distortion block (DPD, 1111c), a digital-to-analog converter (DAC, 1112c), a pre-driver (Pre-driver, 1113c), a power amplifier (PA, 1114c), and a transmit antenna (Tx Antenna, 1115c). Each block may perform the following roles.
[0429] Transmit baseband block (1110c): Digital processing block for the transmit signal
[0430] Digital Line Distortion Block (1111c): Line distortion of a digital transmission signal
[0431] Digital-to-Analog Converter (1112c): Converts digital signals to analog signals
[0432] Pre-driver (1113c): Gradual power amplification of the analog transmission signal
[0433] Power amplifier (1114c): Power amplification of an analog transmission signal
[0434] Transmitting antenna (1115c): Antenna for transmitting signals
[0435] According to the transmit / receive structure illustrated in FIG. 11c, the receiver may be composed of blocks such as a receiving antenna (Rx Antenna, 1124c), a low-noise amplifier (LNA, 1123c), an analog-to-digital converter (ADC, 1122c), a successive interference canceller (Successive Interference Canceller, 1121c), and a receiving baseband block (Rx Baseband, 1120c). Each block may perform the following roles.
[0436] Receiving antenna (1124c): Antenna for receiving signals
[0437] Low-noise amplifier (1123c): Amplifies the power of the analog received signal while minimizing noise amplification.
[0438] Analog-to-Digital Converter (1122c): Converts analog signals to digital signals
[0439] Continuous Interference Canceller (1121c): Interference Canceller for Digital Signals
[0440] Receive baseband block (1120c): Digital processing block for the received signal
[0441] According to the transmission and reception structure illustrated in FIG. 11c, a power amplifier coupler (PA Coupler, 1116c) and a coefficient update block (Coefficient Update, 1117c) may exist for additional signal processing between the transmitting end and the receiving end. Each block can perform the following roles.
[0442] Power amplifier connector (1116c): A block intended for observing the waveform of an analog transmission signal that has passed through a power amplifier at the receiving end.
[0443] Constant Update Block (1117c): Updates various constants required for digital domain signal processing at the transmitter and receiver. The constants calculated here can be used to set various parameters in the transmitter's DPD (1111c) block and the receiver's SIC (1121c) block.
[0444] The transmission and reception structure illustrated in FIG. 11c can be utilized for the purpose of effectively controlling interference between a transmitted signal and a received signal when transmission and reception operations occur simultaneously at a base station or terminal device. For example, when transmission and reception occur simultaneously at any device, a transmitted signal (1101c) transmitted through the transmitting antenna (1115c) of the transmitting end may be received through the receiving antenna (1124c) of the receiving end. In this case, the transmitted signal (801c) received at the receiving end may cause interference (1100c) to the received signal (1102c) that the receiving end originally intended to receive. The interference between the transmitted signal (1101c) and the received signal (1102c) received at the receiving end is referred to as self-interference (1100c). To explain specifically with an example, if a base station device simultaneously performs downlink transmission and uplink reception, the downlink signal transmitted by the base station may be received at the base station's receiver. Consequently, interference may occur at the receiver between the downlink signal transmitted by the base station and the uplink signal that the base station originally intended to receive. Similarly, if a terminal device simultaneously performs downlink reception and uplink transmission, the uplink signal transmitted by the terminal may be received at the terminal's receiver. This may result in interference at the terminal's receiver between the uplink signal transmitted by the terminal and the downlink signal that the terminal originally intended to receive. Such interference between links in different directions—specifically, downlink and uplink signals—at the base station and the terminal device is sometimes referred to as cross-link interference.
[0445] In one embodiment of the present disclosure, magnetic interference between a transmitted signal (or downlink signal) and a received signal (or uplink signal) may occur in a system where transmission and reception can occur simultaneously.
[0446] For example, magnetic interference may occur in the aforementioned XDD system.
[0447] Figure 11d is a diagram illustrating an example of downlink and uplink resource configuration in an XDD system.
[0448] In the case of XDD, downlink (1100d) resources and uplink (1103d) resources can be distinguished in the frequency domain, and a guard band (GB, 1104d) may exist between the downlink (1100d) resources and the uplink (1101d) resources. Actual downlink transmission may occur within the downlink bandwidth (1102d), and uplink transmission may occur within the actual uplink bandwidth (1103d). At this time, leakage (1106d) may occur outside the uplink or downlink transmission band. In the area where the downlink resources (1100d) and uplink resources (1101d) are adjacent, interference caused by such leakage (which can be named Adjacent Carrier Leakage (ACL, 1105)) may occur. FIG. 11d illustrates an example of an ACL (1105d) occurring from a downlink (1100d) to an uplink (1101d). As the downlink bandwidth (1102d) and the uplink bandwidth (1103d) are closer together, the impact of signal interference caused by the ACL (1105d) may increase, and consequently, performance degradation may occur. For example, as shown in FIG. 11d, some resource areas (1106d) within the uplink band (1103d) adjacent to the downlink band (1102d) may be significantly affected by interference caused by the ACL (1105d). In some resource areas (1107d) within the uplink band (1103d) relatively far from the downlink band (1102d), the impact of interference caused by the ACL (1105d) may be small. That is, within the uplink band (1103d), there may exist a resource area (1106d) that is relatively heavily affected by interference and a resource area (1107d) that is relatively less affected by interference. A protection band (1104d) may be inserted between the downlink bandwidth (1102d) and the uplink bandwidth (1103d) for the purpose of reducing performance degradation caused by the ACL (1105d).As the size of the guard band (1104d) increases, there is an advantage in that the interference effect caused by the ACL (1105d) between the downlink bandwidth (1102d) and the uplink bandwidth (1103d) can be reduced; however, as the size of the guard band (1104d) increases, the resources available for transmission and reception decrease, which may result in a disadvantage of reduced resource efficiency. Conversely, as the size of the guard band (1104d) decreases, the amount of resources available for transmission and reception can increase, which may result in higher resource efficiency; however, there is a disadvantage in that the interference effect caused by the ACL (1105d) between the downlink bandwidth (1102d) and the uplink bandwidth (1103d) may increase. Therefore, it may be important to determine an appropriate size of the guard band (904) by considering the trade-off.
[0449] Meanwhile, 3GPP is discussing SBFD (Subband non-overlapping Full Duplex) as a new duplex method based on NR. SBFD is a technology that utilizes a portion of downlink resources as uplink resources in the TDD spectrum of frequencies below or above 6 GHz, thereby receiving uplink transmissions from terminals to expand the uplink coverage of the terminals by the amount of increased uplink resources, and can reduce feedback delay by receiving feedback on downlink transmissions from the terminals within the expanded uplink resources. In this disclosure, a terminal capable of receiving information from a base station regarding SBFD support and performing uplink transmissions within a portion of downlink resources may be referred to as an SBFD terminal (SBFD-capable UE) for convenience. To define the above SBFD method in the standard and for an SBFD terminal to determine whether the SBFD is supported in a specific cell (or frequency, frequency band), the following method may be considered.
[0450] First method. In addition to the existing frame structure types of unpaired spectrum (or time division duplex, TDD) or paired spectrum (or frequency division duplex, FDD), another frame structure type (e.g., frame structure type 2) may be introduced to define the above SBFD. The above frame structure type 2 may be defined as being supported at the specific frequency or frequency band, or the base station may instruct the terminal whether SBFD is supported through system information. The SBFD terminal may receive system information including whether SBFD is supported and determine whether SBFD is supported in the specific cell (or frequency, frequency band).
[0451] Second method. Without defining a new frame structure type, it may be indicated whether the SBFD is additionally supported at a specific frequency or frequency band of the existing unpaired spectrum (or TDD). In the second method, it may be defined whether the SBFD is additionally supported at a specific frequency or frequency band of the existing unpaired spectrum, or the base station may indicate to the terminal whether the SBFD is supported using system information. The SBFD terminal may receive system information including whether the SBFD is supported and determine whether the SBFD is supported in the specific cell (or frequency, frequency band).
[0452] In the first and second methods above, the information regarding SBFD support may be information indicating whether SBFD is supported indirectly by additionally setting a part of the downlink resource as an uplink resource in addition to the setting of TDD UL (uplink)-DL (downlink) resource configuration information indicating TDD downlink slot (or symbol) resources and uplink slot (or symbol) resources (e.g., SBFD resource configuration information in FIG. 11e described later), or it may be information indicating whether SBFD is supported directly.
[0453] In the present disclosure, the SBFD terminal may obtain cell synchronization by receiving a synchronization signal block during an initial cell connection for connecting to a cell (or base station). The process of obtaining cell synchronization may be the same for the SBFD terminal and the existing TDD terminal. Subsequently, the SBFD terminal may determine whether the cell supports SBFD through MIB acquisition, SIB acquisition, or a random access process.
[0454] The system information for transmitting information regarding SBFD support may be system information transmitted separately, distinguished from system information for a terminal supporting a different version of the standard within the cell (e.g., an existing TDD terminal), and the SBFD terminal may determine whether SBFD is supported by acquiring all or part of the system information transmitted separately from the system information for the existing TDD terminal. If the SBFD terminal acquires only the system information for the existing TDD terminal or acquires system information regarding SBFD non-support, the cell (or base station) may determine that it supports only TDD.
[0455] If the information regarding SBFD support is included in system information for a terminal that supports a different version of the standard (e.g., an existing TDD terminal), the information regarding SBFD support may be inserted at the very end so as not to affect the acquisition of system information by the existing TDD terminal. If the SBFD terminal fails to acquire the information regarding SBFD support inserted at the very end, or acquires information that SBFD is not supported, the SBFD terminal may determine that the cell (or base station) supports only TDD.
[0456] If the information regarding SBFD support is included in the system information for a terminal supporting a different version of the specification (e.g., an existing TDD terminal), the information regarding SBFD support may be transmitted via a separate PDSCH so as not to affect the acquisition of system information for the existing TDD terminal. That is, a terminal that does not support SBFD may receive a first SIB (or SIB1) containing existing TDD-related system information from the first PDSCH. A terminal that supports SBFD may receive a first SIB (or SIB) containing existing TDD-related system information from the first PDSCH and may receive a second SIB containing SBFD-related system information from the second PDSCH. Here, the first PDSCH and the second PDSCH may be scheduled as the first PDCCH and the second PDCCH, and the cyclic redundancy code (CRC) of the first PDCCH and the second PDCCH may be scrambled with the same RNTI (e.g., SI-RNTI). The search space for monitoring the second PDCCH can be obtained from the system information of the first PDSCH, and if it cannot be obtained (i.e., if the system information of the first PDSCH does not include information about the search space), the second PDCCH can be received in the same search space as the search space of the first PDCCH.
[0457] As described above, if the SBFD terminal determines that the cell (or base station) supports only TDD, the SBFD terminal can perform random access procedures and transmit / receive data / control signals in the same way as an existing TDD terminal.
[0458] A base station may configure separate random access resources for each of the existing TDD terminals or SBFD terminals (e.g., an SBFD terminal supporting duplex communication and an SBFD terminal supporting half-duplex communication), and transmit configuration information for said random access resources (control information or configuration information indicating time-frequency resources that can be used for PRACH) to the SBFD terminals through system information. The system information for transmitting information about said random access resources may be system information transmitted separately, distinct from system information for terminals supporting different versions of specifications within the cell (e.g., existing TDD terminals).
[0459] The base station may be able to distinguish whether a TDD terminal supporting a different version of the standard performs random access or an SBFD terminal performs random access by setting a separate random access resource for the TDD terminal supporting a different version of the standard and the SBFD terminal. For example, the separate random access resource set for the SBFD terminal may be a resource that the existing TDD terminal determines to be a downlink time resource, and the SBFD terminal performs random access through an uplink resource (or a separate random access resource) set on a part of the frequency of the downlink time resource, so that the base station can determine that the terminal attempting random access from the uplink resource is an SBFD terminal.
[0460] Alternatively, the base station may not set a separate random access resource for the SBFD terminal, but may set a common random access resource for all terminals within the cell. In this case, configuration information regarding the random access resource may be transmitted to all terminals within the cell via system information, and the SBFD terminal that receives the system information may perform random access to the random access resource. Afterward, the SBFD terminal may complete the random access process and proceed to an RRC connection mode to transmit and receive data with the cell. After the RRC connection mode, the SBFD terminal may receive an upper or physical signal from the base station that determines that a portion of the frequency resources of the downlink time resources is set as an uplink resource, and may transmit an uplink signal from the uplink resource as an SBFD operation.
[0461] When the SBFD terminal determines that the cell supports SBFD, it can notify the base station that the terminal attempting to connect is an SBFD terminal by transmitting capability information to the base station that includes at least one of the following: whether the terminal supports SBFD, whether it supports full-duplex or half-duplex communication, and the number of transmitting or receiving antennas it has (or supports). Alternatively, if half-duplex communication support is a mandatory implementation for the SBFD terminal, the half-duplex communication support status may be omitted from the capability information. The SBFD terminal's report regarding the capability information may be reported to the base station through a random access process, after the random access process is completed, or after proceeding to an RRC connection mode for transmitting and receiving data with the cell.
[0462] The above SBFD terminal may support half-duplex communication, which performs only uplink transmission or downlink reception at a time like an existing TDD terminal, or it may support full-duplex communication, which performs both uplink transmission and downlink reception at a time. Accordingly, whether the above half-duplex or full-duplex communication is supported can be reported to the base station by the SBFD terminal through a capability report, and after the report, the base station may configure the SBFD terminal to transmit and receive using half-duplex communication or full-duplex communication. When the SBFD terminal reports the capability for half-duplex communication to the base station, a switching gap to change RF between transmission and reception may be required when operating in FDD or TDD, as a duplexer generally does not exist.
[0463] FIG. 11e is a diagram illustrating an example of SBFD operating in the TDD band of a wireless communication system to which the present disclosure applies.
[0464] Figure 11e (a) illustrates a case where TDD is operated in a specific frequency band. In a cell operating the TDD, the base station can transmit and receive signals containing data / control information in the downlink slot (or symbol), uplink slot (or symbol) (1101e), and flexible slot (or symbol) based on the configuration of TDD UL-DL resource configuration information indicating the downlink slot (or symbol) resource and uplink slot (or symbol) resource of the existing TDD terminal or SBFD terminal.
[0465] In Fig. 11e, it can be assumed that the DDDSU slot format is configured according to the TDD UL-DL resource configuration information. Here, 'D' represents a slot composed entirely of downlink symbols, 'U' represents a slot composed entirely of uplink symbols, and 'S' represents a slot that is neither 'D' nor 'U'—that is, a slot containing downlink symbols, uplink symbols, or flexible symbols. For convenience, it can be assumed here that S consists of 12 downlink symbols and 2 flexible symbols. Furthermore, the DDDSU slot format can be repeated according to the TDD UL-DL resource configuration information. That is, the repetition cycle of the TDD configuration is 5 slots (5ms for 15kHz SCS, 2.5ms for 30kHz SCS, etc.).
[0466] Next, Figures 11e (b), (c) to (d) illustrate cases where SBFD is operated together with TDD in a specific frequency band.
[0467] Referring to (b) of FIG. 11e, the terminal may be configured to set a portion of the cell's frequency band as a frequency band (1110e) capable of uplink transmission. This band may be called an uplink subband (UL subband). The uplink subband (UL subband) may be applied to all symbols of all slots. The terminal may transmit an uplink channel or signal scheduled to all symbols (1112e) within the subband (UL subband). However, the terminal may not transmit an uplink channel or signal in a band other than the subband (UL subband).
[0468] Referring to (c) of FIG. 11e, the terminal can be configured to set a portion of the cell's frequency band as a frequency band (1120e) capable of uplink transmission, and can be configured to set a time range in which said frequency band is activated. Here, this frequency band can be called an uplink subband (UL subband). In FIG. 11e(c), the uplink subband (UL subband) is deactivated in the first slot, and the uplink subband (UL subband) can be activated in the remaining slots. Therefore, the terminal can transmit an uplink channel or signal in the uplink subband (UL subband) (1122e) of the remaining slots. Thus, although the uplink subband (UL subband) is activated on a slot basis here, the activation status can be configured on a symbol basis.
[0469] Referring to (d) of FIG. 11e, the terminal may be configured with a time-frequency resource capable of uplink transmission. The terminal may be configured with one or more time-frequency resources capable of uplink transmission. For example, a portion of the frequency band (1132e) of the first slot and the second slot may be configured with a time-frequency resource capable of uplink transmission. Additionally, a portion of the frequency band (1133e) of the third slot and a portion of the frequency band (1134e) of the fourth slot may be configured with a time-frequency resource capable of uplink transmission.
[0470] In the following description, time-frequency resources capable of uplink transmission within a downlink symbol or slot may be referred to as SBFD resources. Additionally, a symbol with an uplink subband set within a downlink symbol may be referred to as an SBFD symbol. Furthermore, time-frequency resources capable of downlink reception within an uplink symbol or slot may be referred to as SBFD resources. Additionally, a symbol with a downlink subband set within an uplink symbol may be referred to as an SBFD symbol.
[0471] For convenience, in this disclosure, a downlink channel or a band capable of receiving signals, excluding the uplink subband, is referred to as a downlink subband. A terminal can set up to one uplink subband per symbol and up to two downlink subbands. For example, a terminal can be set to one of {uplink subband, downlink subband}, {downlink subband, uplink subband}, or {first downlink subband, uplink subband, second downlink subband} in the frequency domain.
[0472] FIG. 11f is a drawing illustrating an SBFD setting according to one embodiment of the present disclosure.
[0473] Referring to FIG. 11f, the terminal can receive uplink symbols, downlink symbols, or flexible symbols according to the TDD configuration. Here, in the 'D' slot, all symbols in the slot are downlink symbols. In the 'U' slot, all symbols in the slot are uplink symbols. The 'S' slot is a slot that is neither the 'D' slot nor the 'U' slot. The terminal can receive UL BWP (1120f). Also, the terminal can receive UL subband (1110f) within the DL symbols. Additionally, the terminal can receive slots or symbols to which the UL subband (1110f) is to be applied. Referring to FIG. 11f, the UL subband may be applied only to some of the DL symbols of the TDD periodicity. The DL symbols in the second and third slots may have the UL subband applied, but other DL symbols may not have the UL subband applied. Here, the SBFD symbol may represent a symbol to which the UL subband applies.
[0474] A base station may set a guard frequency interval between the DL subband and the UL subband at the terminal. When the guard frequency interval is set at the terminal, the frequency resources in the frequency domain may be divided into the UL subband, the guard frequency interval, and the DL subband. For the purpose of explaining this embodiment, it is assumed that the guard frequency interval is included in the UL subband. That is, in the following description, the expression "if X overlaps with the UL subband" can be interpreted as "if X overlaps with the UL subband or the guard frequency interval." Additionally, the expression "if X overlaps with the UL subband" can be interpreted as "if X does not overlap with the DL subband."
[0475] The expression "if X does not overlap with the UL subband" can be interpreted as "if X does not overlap with the UL subband and the Guard frequency range." Additionally, the expression "if X does not overlap with the UL subband" can be interpreted as "if X overlaps with the DL subband."
[0476] Embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Hereinafter, a base station is an entity that performs resource allocation for terminals and may be at least one of a gNode B, gNB, eNode B, Node B, BS (Base Station), wireless access unit, base station controller, or a node on a network. A terminal may include a UE (User Equipment), MS (Mobile Station), cellular phone, smartphone, computer, or a multimedia system capable of performing communication functions. Although embodiments of the present disclosure are described below using a 5G system as an example, embodiments of the present disclosure may be applied to other communication systems having similar technical backgrounds or channel types. For example, LTE or LTE-A mobile communication and mobile communication technologies developed after 5G may be included therein. Accordingly, embodiments of the present disclosure may be applied to other communication systems with some modifications without significantly departing from the scope of the present disclosure, in the judgment of a person skilled in the art. The contents of the present disclosure are applicable to FDD, TDD and / or XDD (and / or SBFD, full duplex) systems.
[0477] Furthermore, in describing the present disclosure, if it is determined that a detailed description of related functions or configurations could unnecessarily obscure the essence of the present disclosure, such detailed description is omitted. Additionally, the terms described below are defined in consideration of their functions within the present disclosure, and these definitions may vary depending on the intentions or practices of the user or operator. Therefore, their definitions should be based on the content throughout this specification.
[0478] In describing the present disclosure below, the term "upper layer signaling" may refer to a signaling corresponding to at least one or a combination of at least one of the following signalings.
[0479] - MIB (Master Information Block)
[0480] - SIB (System Information Block) or SIB
[0481] - RRC (Radio Resource Control)
[0482] - MAC (Medium Access Control) CE (Control Element)
[0483] In addition, L1 signaling may be a signaling corresponding to at least one or a combination of at least one of the following physical layer channels or signaling methods using signaling.
[0484] - PDCCH (Physical Downlink Control Channel)
[0485] - DCI (Downlink Control Information)
[0486] - Terminal-specific (UE-specific) DCI
[0487] - Group common DCI
[0488] - Common DCI
[0489] - Scheduling DCI (e.g., DCI used for the purpose of scheduling downlink or uplink data)
[0490] - Non-scheduling DCI (e.g., DCI not intended for scheduling downlink or uplink data)
[0491] - PUCCH (Physical Uplink Control Channel)
[0492] - UCI (Uplink Control Information)
[0493] The term "slot" used in the present disclosure below is a general term that may refer to a specific time unit corresponding to TTI (transmit time interval, transmission time interval), and specifically, it may refer to a slot used in a 5G NR system, or a slot or subframe used in a 4G LTE system.
[0494] In the following disclosure, the examples are described through a number of embodiments, but these are not independent, and one or more embodiments may be applied simultaneously or in combination.
[0495] FIG. 12 is a drawing illustrating an example of a non-SBFD symbol of a wireless communication system according to one embodiment of the present disclosure.
[0496] Referring to FIG. 12, the entire RB located at the non-SBFD symbol (1201) of the carrier (1202) can be used in downlink (DL), uplink (UL), or sidelink (SL) transmission depending on the transmission direction.
[0497] According to one embodiment of the present disclosure, a terminal and a base station may perform operations based on SBFD (subband full duplex, subband non-overlapping full duplex). The SBFD subband in which the SBFD operation is performed may consist of at least one consecutive RB, and the resources belonging to the SBFD subband have the same transmission direction. That is, all resources belonging to a single SBFD subband may be used in the downlink, uplink, or sidelink. The SBFD operation may be performed by utilizing some resources of the TDD carrier.
[0498] A base station can configure a BWP for SBFD operation on a terminal. The BWP configured by the base station may include a DL-BWP (Downlink Bandwidth Part), an UL-BWP (Uplink Bandwidth Part), and an SL-BWP (Sidelink Bandwidth Part). The base station and the terminal can perform communication using SBFD symbols (symbols in which SBFD subbands are located on the time axis). Up to one UL subband may be located in an SBFD symbol. One or up to two DL subbands may be located in an SBFD symbol. The UL subbands located in an SBFD symbol may be located in the central part of the carrier or at one end. The location of the SBFD symbol may be configured in a DL symbol or a Flexible symbol.
[0499] FIGS. 13, 14, and 15 illustrate an example of an SBFD symbol of a wireless communication system according to an embodiment of the present disclosure. Some of the RBs (one or more of the RBs included in the carrier) located at the SBFD symbols (1301, 1401, 1501) of the carrier (1302, 1402, 1502) may belong to a downlink subband and an uplink subband (1303, 1403, 1503). For example, the location of the uplink subband (1303, 1403, 1503) located at the SBFD symbol (1301, 1401, 1501) may be located at the central part of the uplink carrier as shown in FIG. 13, at one end having a low RB index as shown in FIG. 14 (one or more RBs consecutive in the frequency axis starting from the RB with the lowest index among the RBs included in the carrier), or at one end having a high RB index as shown in FIG. 15 (one or more RBs consecutive in the frequency axis starting from the RB with the highest index among the RBs included in the carrier).
[0500] According to one embodiment of the present disclosure, the location of an SBFD symbol may be signaled to a terminal. For example, the location of an SBFD symbol may be signaled by one or more combinations of an RRC message, a System Information Block (SIB) message, MAC CE, and DCI.
[0501] According to one embodiment of the present disclosure, the location of an SBFD subband may be signaled to a terminal. For example, the location of an SBFD subband may be signaled by one or more combinations of an RRC message, a SIB message, MAC CE, and DCI. According to one embodiment of the present disclosure, the size of the SBFD subband (subband bandwidth) set in the terminal may be set in RB units, that is, in multiple RB units. According to one embodiment of the present disclosure, the size of the SBFD subband set in the terminal may be set in a unit that groups multiple RBs into one group, that is, to include multiple said groups. The said unit may include, for example, an RBG (RB Group), a PRG (Precoding Resource block Group), etc.
[0502] According to one embodiment of the present disclosure, a base station and a terminal can communicate using SBFD symbols. For example, the base station can transmit data to the terminal using the DL subband of the SBFD symbol, and the terminal can transmit data to the base station using the UL subband of the SBFD symbol. As another example, sidelink communication between terminals can be performed using SBFD symbols. For example, the terminal can transmit and receive a sidelink signal using the UL subband of the SBFD symbol.
[0503] According to one embodiment of the present disclosure, a base station may transmit data to a terminal by using SBFD symbols and non-SBFD symbols (symbols where the SBFD subband is not located) together. For example, a base station may transmit PDSCH to a terminal by using SBFD symbols and non-SBFD symbols together. A base station may transmit data to a terminal via PDSCH by using SBFD symbols and non-SBFD symbols included in a single slot together. A base station may transmit data to a terminal via PDSCH by using a slot containing SBFD symbols and a slot containing non-SBFD symbols together.
[0504] According to one embodiment of the present disclosure, a terminal can transmit data to a base station by using SBFD symbols and non-SBFD symbols together. The terminal can transmit PUSCH to a base station by using SBFD symbols and non-SBFD symbols together. The terminal can transmit data to a base station via PUSCH by using SBFD symbols and non-SBFD symbols included in a single slot together. The terminal can transmit data to a base station via PUSCH by using a slot containing SBFD symbols and a slot containing non-SBFD symbols together.
[0505] According to one embodiment of the present disclosure, a terminal can transmit data to another terminal by using SBFD symbols and non-SBFD symbols together. The terminal can transmit a physical sidelink shared channel (PSSCH) to another terminal by using SBFD symbols and non-SBFD symbols together. The terminal can transmit data to another terminal via the PSSCH by using SBFD symbols and non-SBFD symbols included in a single slot together. The terminal can transmit data to another terminal via the PSSCH by using a slot containing SBFD symbols and a slot containing non-SBFD symbols together.
[0506] According to one embodiment of the present disclosure, one TTI may include at least one SBFD symbol and / or at least one non-SBFD symbol.
[0507] According to one embodiment of the present disclosure, when the symbols used for transmission include both SBFD symbols and non-SBFD symbols, the amount of available frequency resources in SBFD symbols and the amount of available frequency resources in non-SBFD symbols may differ. For example, the number of RBs included in the DL subband located in the SBFD symbol may be less than or equal to the number of RBs located in the DL non-SBFD symbol. The number of RBs included in the UL subband located in the SBFD symbol may be less than or equal to the number of RBs located in the UL non-SBFD symbol. The sum of the number of RBs included in the DL subband located in the SBFD symbol and the number of RBs included in the UL subband located in the SBFD symbol may be less than or equal to the number of RBs located in the non-SBFD symbol.
[0508] FIGS. 16 and FIGS. 17 illustrate slots of a wireless communication system according to one embodiment of the present disclosure. Slots (1601, 1701) containing only SBFD symbols and slots (1602, 1702) containing only non-SBFD symbols may be located consecutively. As illustrated, uplink subbands (1603, 1703) and downlink subbands (1604, 1704) may be located in slots (1601, 1701) containing only SBFD symbols. In FIGS. 16 and 17, slots (1601, 1701) containing only SBFD symbols are shown to be ahead of slots (1602, 1702) containing only non-SBFD symbols, but conversely, slots (1601, 1701) containing only SBFD symbols may be behind slots (1602, 1702) containing only non-SBFD symbols.
[0509] According to one embodiment of the present disclosure, parameters related to a Conditional Handover (CHO) may be set by a base station to a terminal. The setting may be transmitted to the terminal via RRC signaling. The setting parameters may include conditions under which the terminal initiates a handover. The conditions may include, for example, various events (A3, A4, A5, D1, D2, T1, etc.) and parameters associated with each event (offset, threshold, hysteresis, time to Triger, etc.). The terminal may receive the CHO setting, evaluate whether the conditions included in the CHO setting are satisfied, and perform a handover operation if the conditions are satisfied. The handover operation may include the terminal transmitting a PRACH preamble and waiting for a response from the base station. The definitions of the exemplified events may be referenced in Table 24 below.
[0510] [Table 24]
[0511]
[0512] FIG. 18 illustrates an example of a conditional handover operation according to one embodiment of the present disclosure. The flowchart of FIG. 18 illustrates an exemplary method that can be implemented according to the principles of the present disclosure, and various modifications may be made to the method illustrated in the flowchart. For example, although illustrated as a series of steps, the various steps in each figure may overlap, occur in parallel, occur in a different order, or occur multiple times. In other examples, steps may be omitted or replaced with other steps.
[0513] Referring to FIG. 18, the terminal can receive a Conditional Handover (CHO) setting (1810). The terminal can evaluate whether the condition is satisfied by measuring the signal strength (e.g., RSSI (received signal strength indicator), RSRP (reference signal received power)) and comparing it with the set condition (1820). If the condition is satisfied (1830), the terminal performs a conditional handover operation (1840), and if it is not satisfied (1830), it can remain in the corresponding cell (source cell) and evaluate whether the condition is satisfied.
[0514] According to one embodiment of the present disclosure, parameters related to LTM (Lower-layer Triggered Mobility / layer 1 / layer 2 (L1 / L2) triggered mobility) may be configured in a terminal by a base station. The configuration may be transmitted to the terminal via RRC signaling. The configuration parameters may include 'configuration(s) for an LTM candidate cell', 'configuration(s) for CSI-RS resources required for LTM operation', etc. The 'configuration(s) for an LTM candidate cell' may include the cell ID (physical cell ID) of the candidate cell, the SSB configuration of the candidate cell, and the configuration for fast uplink synchronization of the candidate cell (EarlyUL-SyncConfig). Upon receiving such configurations, the terminal may perform measurement and reporting on the candidate cells. Additionally, the terminal may perform downlink / uplink synchronization in advance for the candidate cells.
[0515] According to one embodiment of the present disclosure, a terminal receives a 'Candidate Cell TCI States Activation MAC CE' transmitted by a base station and can perform downlink synchronization to the candidate cell indicated by the MAC CE.
[0516] According to one embodiment of the present disclosure, a terminal receives a 'PDCCH order' transmitted by a base station and can transmit a PRACH preamble in response thereto. The PDCCH order may be transmitted to the terminal by a DCI transmitted via the PDCCH. The DCI may be, for example, DCI format 1_0, and the DCI format 1_0 may include a 'Cell indicator' parameter indicating which cell is instructed to transmit the PRACH preamble. The terminal may transmit the PRACH preamble to the candidate cell indicated by the 'Cell indicator' among the candidate cell(s) included in the 'setting(s) for LTM candidate cells'. The bitwidth of the 'Cell indicator' field may be determined by the number of candidate cell(s) including EarlyUL-SyncConfig among the candidate cell(s) included in the 'setting(s) for LTM candidate cells'. The base station receives the PRACH preamble transmitted by the terminal through the above 'PDCCH order', determines the TA (Timing Advance) value, and can transmit it to the terminal through the 'LTM Cell Switch Command MAC CE'.
[0517] FIG. 19 illustrates an example of an LTM operation according to one embodiment of the present disclosure. The flowchart of FIG. 19 illustrates an exemplary method that can be implemented according to the principles of the present disclosure, and various modifications may be made to the method illustrated in the flowchart. For example, although illustrated as a series of steps, the various steps in each figure may overlap, occur in parallel, occur in a different order, or occur multiple times. In other examples, steps may be omitted or replaced with other steps.
[0518] Referring to FIG. 19, the terminal can receive a Lower-layer Triggered Mobility (LTM) setting (1910). The terminal can perform downlink synchronization on at least some of the set LTM candidate cell(s) using the setting value (1920). The terminal can receive a PDCCH order transmitted by the base station and transmit a PRACH preamble to the LTM candidate cell pointed to by the PDCCH order (1930). The terminal can receive an LTM cell change command MAC CE transmitted by the base station (1940) and receive a TA value included in the LTM cell change command MAC CE to perform a handover operation to the cell pointed to by the LTM cell change command MAC CE.
[0519] According to one embodiment of the present disclosure, parameters related to Conditional Handover (CHO) and parameters related to Lower-layer Triggered Mobility (LTM) may be set to a terminal by a base station. The settings may be transmitted to the terminal via RRC signaling. Through the settings, the terminal may perform a conditional LTM operation. The setting parameters may include 'handover conditions of the terminal', 'setting(s) for LTM candidate cells', 'setting(s) for CSI-RS resources required for LTM operation', etc. Upon receiving such settings, the terminal may perform measurement / reporting on candidate cells, perform downlink / uplink synchronization in advance for candidate cells, and perform a handover operation when the set conditions are satisfied.
[0520] According to one embodiment of the present disclosure, during a conditional LTM process, a terminal receives a 'PDCCH order' transmitted by a base station and can transmit a PRACH preamble in response thereto. The description of the DCI transmitting the 'PDCCH order' is as described above. The candidate cell indicated by the 'PDCCH order' receives the PRACH preamble transmitted by the terminal by the 'PDCCH order', and a TA (Timing Advance) value can be transmitted to the terminal by the source cell. The TA value can be determined by a base station managing the candidate cell or the source cell. If the TA value is determined by a base station (or a module of a base station) managing the candidate cell, the base station (or a module of a base station) managing the candidate cell can transmit the determined TA value to a base station (or a module of a base station) managing the source cell. When the above TA value is determined by the base station (or base station module) managing the source cell, the base station (or base station module) managing the above candidate cell transmits PRACH reception related data (raw data, sampling data) to the base station (or base station module) managing the source cell so that the base station (or base station module) managing the source cell can determine the TA value. The above TA value may be transmitted to the terminal through a 'RAR (Random Access Response)' or a 'MAC CE defined for early TA transmission'.
[0521] FIG. 20 illustrates an example of a conditional LTM operation according to an embodiment of the present disclosure. The flowchart of FIG. 20 illustrates an exemplary method that can be implemented according to the principles of the present disclosure, and various modifications may be made to the method illustrated in the flowchart. For example, although illustrated as a series of steps, the various steps in each figure may overlap, occur in parallel, occur in a different order, or occur multiple times. In other examples, steps may be omitted or replaced with other steps.
[0522] The terminal can receive a Conditional LTM (Lower-layer Triggered Mobility) setting (2010). The terminal can perform downlink synchronization on at least some of the set LTM candidate cell(s) using the setting value (2020). The terminal receives a PDCCH order transmitted by the base station and can transmit a PRACH preamble to the LTM candidate cell indicated by the PDCCH order (2030). The terminal can receive a TA value from the source cell. This TA value can be transmitted to the terminal via RAR or MAC CE (2040). The terminal can evaluate whether the condition is satisfied by measuring the signal strength (e.g., RSSI, RSRP) and comparing it with the set condition (2050). If the condition is satisfied (2060), the terminal performs a conditional handover operation (2070), and if it is not satisfied (2060), it can remain in the corresponding cell (source cell) and evaluate whether the condition is satisfied.
[0523] According to one embodiment of the present disclosure, a terminal that transmits a PRACH preamble to a candidate cell 1 indicated by a 'PDCCH order' can perform an operation to receive a DCI format 1_0 with a CRC scrambled into RA-RNTI from a source cell (a currently connected cell, a cell that transmitted the 'PDCCH order') during a 'RAR window'.
[0524] According to one embodiment of the present disclosure, a terminal that transmits a PRACH preamble to a candidate cell 2 indicated by a 'PDCCH order' can perform an operation to receive a DCI format 1_0 with a CRC scrambled into RA-RNTI from a source cell (a currently connected cell, a cell that transmitted the 'PDCCH order') during a 'RAR window'.
[0525] According to one embodiment of the present disclosure, a terminal that transmits a PRACH preamble to a source cell (currently connected cell) indicated by a 'PDCCH order' can perform an operation to receive a DCI format 1_0 with a CRC scrambled into RA-RNTI from the source cell (currently connected cell, cell that transmitted the 'PDCCH order') during a 'RAR window'.
[0526] It may be necessary to distinguish which cell the TA value transmitted via the PDSCH scheduled by the DCI format 1_0, which has its CRC scrambled with RA-RNTI, is intended for. As in the example above, since the RAR (PDSCH) for each PRACH preamble transmitted to candidate cell 1, candidate cell 2, and source cell, and the DCI format 1_0 scheduling the PDSCH, are all received by the source cell, it may be necessary to distinguish which cell the TA value received via the RAR (PDSCH) is intended for.
[0527] According to one embodiment of the present disclosure, the RA-RNTI may vary depending on the cell to which the PRACH preamble is transmitted. For example, it may differ when the PRACH preamble is transmitted to a source cell and when the PRACH preamble is transmitted to a candidate cell.
[0528] According to one embodiment of the present disclosure, cell-related parameters may be used when calculating the RA-RNTI value. According to one embodiment of the present disclosure, LTM setting-related parameters (e.g., ltm-CandidateId, etc.) may be used when calculating the RA-RNTI value.
[0529] According to one embodiment of the present disclosure, RA-RNTI can be calculated using the following formula.
[0530] RA-RNTI = 1 + s_id + 14 × t_id + 14 × 80 × f_id + 14 × 80 × 8 × ul_carrier_id +14 × 80 × 8 × 2 × ltm-CandidateId
[0531] According to one embodiment of the present disclosure, s_id is the first OFDM symbol index of the PRACH occasion in which the PRACH preamble was transmitted, t_id is the first slot index of the PRACH occasion within the system frame in which the PRACH preamble was transmitted, f_id is the frequency axis index of the PRACH occasion in which the PRACH preamble was transmitted, ul_carrier_id is the index of the uplink carrier in which the PRACH preamble was transmitted (0: NUL (normal uplink carrier), 1: SUL (supplementary uplink carrier)), and ltm-CandidateId is the index of the cell in which the PRACH preamble was transmitted (0: source cell, remainder: ltm-CandidateId of the cell set as a candidate cell).
[0532] According to one embodiment of the present disclosure, a 'cell indicator' value included in a DCI format in which a 'PDCCH order' instructing the transmission of a PRACH preamble is transmitted in the calculation of RA-RNTI may be used. According to one embodiment of the present disclosure, an 'ltm-CandidateId setting value corresponding to the cell indicator value' may correspond to the 'ltm-CandidateId' value of the calculation formula.
[0533] According to one embodiment of the present disclosure, a terminal can determine a cell to which a ‘TA value included in a RAR transmitted by a PDSCH’ scheduled by a ‘DCI in which the CRC is scrambled by the RNTI’ is applied, according to the RNTI separated by cell as described above. For example, if 0 is used as the ltm-CandidateId value in the calculation of the ‘RNTI in which the CRC of the DCI is scrambled’ scheduled by the ‘PDSCH in which the received RAR is transmitted’, the terminal determines that the ‘TA included in the received RAR’ is for a source cell (serving cell), and if a value other than 0 is used as the ltm-CandidateId value, the terminal can determine that the ‘TA included in the received RAR’ is for a candidate cell corresponding to the ltm-CandidateId value.
[0534] According to one embodiment of the present disclosure, cell-related parameters may be used when calculating the RA-RNTI value. According to one embodiment of the present disclosure, when calculating the RA-RNTI value, a field within the DCI (e.g., a 'Cell indicator field', etc.) in which a 'PDCCH order' instructing the transmission of a PRACH preamble is transmitted may be used.
[0535] According to one embodiment of the present disclosure, RA-RNTI can be calculated using the following formula.
[0536] RA-RNTI = 1 + s_id + 14 × t_id + 14 × 80 × f_id + 14 × 80 × 8 × ul_carrier_id +14 × 80 × 8 × 2 × Cell_indicator
[0537] According to one embodiment of the present disclosure, s_id is the first OFDM symbol index of the PRACH occasion in which the PRACH preamble was transmitted, t_id is the first slot index of the PRACH occasion within the system frame in which the PRACH preamble was transmitted, f_id is the frequency axis index of the PRACH occasion in which the PRACH preamble was transmitted, ul_carrier_id is the index of the uplink carrier in which the PRACH preamble was transmitted (0: NUL, 1: SUL), and Cell_indicator is the index of the cell in which the PRACH preamble was transmitted (0: source cell (serving cell), remainder: candidate cell(s) in which EarlyUlSyncConfig is configured among the cell(s) configured as candidate cells).
[0538] According to one embodiment of the present disclosure, a 'Cell indicator field' value included in a DCI format in which a 'PDCCH order' instructing the transmission of a PRACH preamble is transmitted for the calculation of RA-RNTI may be used. According to one embodiment of the present disclosure, the 'Cell indicator field' value may correspond to the 'Cell_indicator' value of the calculation formula.
[0539] According to one embodiment of the present disclosure, only 'candidate cell(s) having EarlyUlSyncConfig among candidate cell(s) set for LTM' are sorted in ascending order according to the 'set ltm-CandidateId' value, and a value starting from 1 may be assigned to the 'candidate cell(s) having EarlyUlSyncConfig among candidate cell(s) set for LTM' sorted in ascending order. The assigned value(s) may be used as the Cell_indicator value of the RA-RNTI calculation formula. A value used in the 'Cell indicator field' may also be determined in the same way as the Cell_indicator value. For example, as shown in Table 25 below, 8 LTM candidate cells are set, and among the 8 candidate cells, EarlyUlSyncConfig is set only in the candidate cells corresponding to ltm-CandadateId values 2, 3, 5, 6, and 8. In this case, the 'Cell_indicator' values corresponding to the candidate cells corresponding to ltm-CandadateId values 2, 3, 5, 6, and 8 may be 1, 2, 3, 4, and 5, respectively.
[0540] [Table 25]
[0541]
[0542]
[0543] According to one embodiment of the present disclosure, a terminal can determine a cell to which a ‘TA value included in a RAR transmitted by a PDSCH’ scheduled by a ‘DCI in which the CRC is scrambled by the RNTI’ is applied, according to the RNTI separated by cell as described above. For example, if 0 is used as the Cell_indicator value in the calculation of the ‘RNTI in which the CRC of the DCI is scrambled’ scheduled by the ‘PDSCH in which the received RAR is transmitted’, the terminal determines that the ‘TA included in the received RAR’ is for a source cell (serving cell), and if a value other than 0 is used as the Cell_indicator value, the terminal determines that the ‘TA included in the received RAR’ is for a candidate cell corresponding to the Cell_indicator value.
[0544] According to one embodiment of the present disclosure, an RA-RNTI is determined as described above, and the 'determined RA-RNTI' may be used for scrambling a PDSCH scheduled by a 'DCI having a CRC that scrambles with the determined RA-RNTI'. According to one embodiment of the present disclosure, a scrambling sequence may be initialized through the following formula, The value may be the RA-RNTI value determined above, and if there is one codeword, the value of q is 0, and if there are two codewords, the value of q may have a value of 0 or 1 for each codeword, and The value Value (physical layer cell identity) (corresponding to the cell and source cell to which the above PDSCH is transmitted It can be a value.
[0545]
[0546] FIG. 21 illustrates an example of an operation in which a terminal checks a TA value in a (conditional) LTM according to an embodiment of the present disclosure. The flowchart of FIG. 21 illustrates an exemplary method that can be implemented according to the principles of the present disclosure, and various modifications may be made to the method illustrated in the flowchart. For example, although illustrated as a series of steps, the various steps in each figure may overlap, occur in parallel, occur in a different order, or occur multiple times. In other examples, steps may be omitted or replaced with other steps.
[0547] Referring to FIG. 21, the terminal receives a PDCCH order transmitted by the base station and can transmit a PRACH preamble to the LTM candidate cell indicated by the PDCCH order (2110). The terminal can identify (calculate, determine) the RA-RNTI corresponding to the LTM candidate cell according to the above-described embodiment (2120). The terminal can monitor DCI format 1_0, in which the CRC is scrambled with the RA-RNTI, while the RAR window is running (2130). The terminal receives the DCI format 1_0 and can receive the PDSCH scheduled by the DCI format 1_0 (2140). The terminal can check the TA value in the RAR transmitted through the PDSCH and apply the TA value to the LTM candidate cell (2150).
[0548] According to one embodiment of the present disclosure, a terminal that transmits a PRACH preamble to a cell indicated by a 'PDCCH order' performs an operation to receive a DCI format 1_0 with a CRC scrambled to RA-RNTI from a source cell (a currently connected cell, a cell that transmitted the 'PDCCH order') during a 'RAR window', and can receive a 'RAR (Random Access Response)' transmitted via a PDSCH scheduled by the DCI format 1_0. According to one embodiment of the present disclosure, the 'RAR (Random Access Response)' may include a 'field containing cell-related information' indicating which cell the 'Timing Advance Command' included in the 'RAR (Random Access Response)' should be applied to.
[0549] According to one embodiment of the present disclosure, the value included in the 'field containing information related to the cell' may be an LTM setting related parameter (e.g., ltm-CandidateId, etc.).
[0550] According to one embodiment of the present disclosure, a value related to a 'cell indicator' value included in a DCI format in which a 'PDCCH order' instructing the transmission of a PRACH preamble is transmitted may be used in the 'field containing information related to the cell'. According to one embodiment of the present disclosure, an 'ltm-CandidateId setting value corresponding to the cell indicator value' may be a value included in the 'field containing information related to the cell'. For example, if eight LTM candidate cells are set, the value included in the 'field containing information related to the cell' included in the RAR may be one of '0 to 8'.
[0551] According to one embodiment of the present disclosure, a terminal can determine the cell to which the 'Timing Advance Command' included in the received RAR is applied based on the 'field containing information related to the cell' (e.g., ltm-CandidateId value). For example, if the value of the 'field containing information related to the cell' (e.g., ltm-CandidateId value) is 0, the terminal determines that the cell to which the 'Timing Advance Command' included in the received RAR is applied is for the source cell (serving cell), and if the value of the 'field containing information related to the cell' (e.g., ltm-CandidateId value) is not 0, the terminal can determine that the cell to which the 'Timing Advance Command' included in the received RAR is applied is for the candidate cell corresponding to the 'non-zero value'.
[0552] According to one embodiment of the present disclosure, the value included in the 'field containing information related to the cell' may be the value of a field within the DCI (e.g., 'Cell indicator field', etc.) to which a 'PDCCH order' instructing the transmission of a PRACH preamble is transmitted. For example, if eight LTM candidate cells are set, and among the eight, five cells have EarlyUlSyncConfig set, the 'Cell indicator' field within the DCI may have a value of '0 to 5 (0: source cell, 1 to 5: candidate cell)'. In such a case, the value included in the 'field containing information related to the cell' included in the RAR may be one of the values of '0 to 5'.
[0553] According to one embodiment of the present disclosure, a terminal can determine the cell to which the 'Timing Advance Command' included in the received RAR is applied based on the 'field containing information related to the cell' (e.g., having a value of 0 to 5 in the case of the example above). For example, if the value of the 'field containing information related to the cell' is 0, the terminal determines that the cell to which the 'Timing Advance Command' included in the received RAR is applied is for a source cell (serving cell), and if the value of the 'field containing information related to the cell' is not 0, the terminal can determine that the cell to which the 'Timing Advance Command' included in the received RAR is applied is for a candidate cell corresponding to the 'non-zero value'.
[0554] According to one embodiment of the present disclosure, a ‘RAR (Random Access Response)’ may include at least one (multiple) pair of a ‘Timing Advance Command’ and a corresponding ‘field containing information related to a cell’ (e.g., ltm-CandidateId value, ‘Cell indicator field’ value).
[0555] According to one embodiment of the present disclosure, a terminal that receives a plurality of pairs of 'Timing Advance Commands' and corresponding 'fields containing information related to cells' through the 'RAR (Random Access Response)' can identify cell(s) through the value of the 'field containing information related to cells', and identify a TA value corresponding to the identified cell(s) in each 'Timing Advance Command' field and apply it to each identified cell(s).
[0556] FIG. 22 illustrates an example of an operation in which a terminal checks a TA value in a (conditional) LTM according to an embodiment of the present disclosure. The flowchart of FIG. 22 illustrates an exemplary method that can be implemented according to the principles of the present disclosure, and various modifications may be made to the method illustrated in the flowchart. For example, although illustrated as a series of steps, the various steps in each figure may overlap, occur in parallel, occur in a different order, or occur multiple times. In other examples, steps may be omitted or replaced with other steps.
[0557] Referring to FIG. 22, the terminal receives a PDCCH order transmitted by the base station and can transmit a PRACH preamble to the LTM candidate cell indicated by the PDCCH order (2210). The terminal can monitor DCI format 1_0 while the RAR window is running (2220). At this time, the aforementioned cell parameters may not be used in the calculation of the RA-RNTI that scrambles the CRC. The terminal receives DCI format 1_0 and can receive a PDSCH scheduled by the DCI format 1_0 (2230). The terminal checks the cell indicator and TA value in the RAR transmitted through the PDSCH and can apply the TA value to the LTM candidate cell indicated by the cell indicator (2240).
[0558] According to one embodiment of the present disclosure, a base station may transmit a TA value to be applied to the 'instructed cell' through MAC CE from a source cell (the cell to which the 'PDCCH order' was transmitted) to a terminal that has transmitted a PRACH preamble to the cell indicated by the 'PDCCH order'.
[0559] According to one embodiment of the present disclosure, the MAC CE may include at least one (multiple) pair of a 'Timing Advance Command' and a corresponding 'field containing information related to a cell' (e.g., ltm-CandidateId value, 'Cell indicator field' value).
[0560] According to one embodiment of the present disclosure, a terminal that receives a plurality of pairs of 'Timing Advance Commands' and corresponding 'fields containing information related to cells' through the MAC CE can identify cell(s) through the value of the 'field containing information related to cells', and identify a TA value corresponding to the identified cell(s) in each 'Timing Advance Command' field and apply it to each identified cell(s).
[0561] FIG. 23 illustrates an example of an operation in which a terminal checks a TA value in a (conditional) LTM according to an embodiment of the present disclosure. The flowchart of FIG. 23 illustrates an exemplary method that can be implemented according to the principles of the present disclosure, and various modifications may be made to the method illustrated in the flowchart. For example, although illustrated as a series of steps, the various steps in each figure may overlap, occur in parallel, occur in a different order, or occur multiple times. In other examples, steps may be omitted or replaced with other steps.
[0562] Referring to FIG. 23, the terminal receives a PDCCH order transmitted by the base station and can transmit a PRACH preamble to the LTM candidate cell indicated by the PDCCH order (2310). The terminal can receive a MAC CE transmitted by the base station (2320). The MAC CE may be a MAC CE that transmits the TA value(s) of the aforementioned LTM candidate cell(s). The type of MAC CE can be distinguished through header values, etc. The terminal can check the cell indicator and TA value in the received MAC CE (2330) and apply the TA value to the LTM candidate cell indicated by the cell indicator.
[0563] According to one embodiment of the present disclosure, a terminal that transmits a PRACH preamble to a candidate cell indicated by a 'PDCCH order' can perform an operation to receive a DCI format 1_0 with a CRC scrambled into RA-RNTI from a source cell (a currently connected cell, a cell that transmitted the 'PDCCH order') during a 'RAR window'.
[0564] According to one embodiment of the present disclosure, a terminal that transmits a PRACH preamble to a source cell (currently connected cell) indicated by a 'PDCCH order' can perform an operation to receive a DCI format 1_0 with a CRC scrambled into RA-RNTI from the source cell (currently connected cell, cell that transmitted the 'PDCCH order') during a 'RAR window'.
[0565] It is necessary to determine which QCL (quasi co-location property) should be applied to receive the above DCI format 1_0.
[0566] According to one embodiment of the present disclosure, when a terminal performs an operation to receive a DCI format 1_0 with a CRC scrambled by RA-RNTI after transmitting a PRACH preamble to a candidate cell, it may use the DM-RS antenna port QCL properties of a CORESET associated with a Type1-PDCCH CSS set. That is, when the terminal receives the DCI format 1_0, it may assume (determine) that the DCI format 1_0 has the same DM-RS antenna port QCL properties as the PDCCH order. The terminal may assume (determine) that the PDCCH DM-RS for the PDCCH containing the DCI format 1_0 has the same QCL properties as the PDCCH order.
[0567] According to one embodiment of the present disclosure, when a terminal performs an operation for receiving a DCI format 1_0 with a CRC scrambled by RA-RNTI after transmitting a PRACH preamble to a candidate cell, it may use the QCL properties of an 'SS / PBCH block (SSB)' associated with the transmission of the PRACH preamble. That is, when the terminal receives the DCI format 1_0, it may assume (determine) that the DCI format 1_0 has the same QCL properties as the 'SS / PBCH block (SSB)'. The terminal may assume (determine) that the PDCCH DM-RS for the PDCCH containing the DCI format 1_0 has the same QCL properties as the 'SS / PBCH block (SSB)'. The 'SS / PBCH block (SSB)' associated with the transmission of the above PRACH preamble may be determined by the value included in the field ('SS / PBCH index') contained in the DCI format in which the 'PDCCH order' commanding the transmission of the above PRACH preamble is transmitted. The above 'SS / PBCH block (SSB)' may be the 'SS / PBCH block (SSB)' of the candidate cell to which the above PRACH preamble was transmitted.
[0568] According to one embodiment of the present disclosure, when a terminal performs an operation to receive a DCI format 1_0 with a CRC scrambled by RA-RNTI after transmitting a PRACH preamble to a candidate cell, it may use the QCL properties of a 'CSI-RS resource' associated with the transmission of the PRACH preamble. That is, when the terminal receives the DCI format 1_0, it may assume (determine) that the DCI format 1_0 has the same QCL properties as the 'CSI-RS resource'. The terminal may assume (determine) that the PDCCH DM-RS for the PDCCH containing the DCI format 1_0 has the same QCL properties as the 'CSI-RS resource'. The 'CSI-RS resource' associated with the transmission of the above PRACH preamble may be determined by a value included in a field ('SS / PBCH index') included in the DCI format through which the 'PDCCH order' commanding the transmission of the above PRACH preamble is transmitted. Alternatively, the DCI format through which the above 'PDCCH order' is transmitted may include a field pointing to the 'CSI-RS resource'. The above 'CSI-RS resource' may be the 'CSI-RS resource' of the candidate cell to which the above PRACH preamble was transmitted.
[0569] According to one embodiment of the present disclosure, when a terminal performs an operation to receive a DCI format 1_0 with a CRC scrambled by RA-RNTI after transmitting a PRACH preamble to a candidate cell, the terminal may assume (determine) the QCL properties assumed (determine) for receiving the DCI format 1_0 determined according to the embodiment as the QCL properties of the PDSCH (including RAR) scheduled by the DCI format 1_0, and receive the PDSCH. The terminal may assume (determine) that the PDSCH DM-RS for the PDSCH (including RAR) has the same QCL properties as the PDCCH DM-RS for the PDCCH containing the DCI format 1_0.
[0570] FIG. 24 illustrates an example of an operation in which a terminal determines a QCL attribute in a (conditional) LTM according to an embodiment of the present disclosure. The flowchart of FIG. 24 illustrates an exemplary method that can be implemented according to the principles of the present disclosure, and various modifications may be made to the method illustrated in the flowchart. For example, although illustrated as a series of steps, the various steps in each figure may overlap, occur in parallel, occur in a different order, or occur multiple times. In other examples, steps may be omitted or replaced with other steps.
[0571] Referring to FIG. 24, the terminal receives a PDCCH order transmitted by a base station and can transmit a PRACH preamble to an LTM candidate cell indicated by the PDCCH order (2410). The terminal can identify (calculate, determine) an RA-RNTI corresponding to the LTM candidate cell according to the above-described embodiment (2420). The terminal can identify (determine) QCL properties for monitoring DCI format 1_0 scrambled with the RA-RNTI according to the above-described embodiment (2430). The terminal can identify (determine) QCL properties for receiving a PDSCH scheduled by the DCI format 1_0 according to the above-described embodiment (2440). The terminal receives DCI format 1_0 and the PDSCH scheduled by the DCI format 1_0 according to the determined QCL properties, and checks the TA value in the RAR transmitted by the PDSCH, and can apply the checked TA value to the identified LTM candidate cell (2450).
[0572] According to one embodiment of the present disclosure, a TimeAlignmentTimer (TAT) may be used for operations related to the LTM candidate cell. The TimeAlignmentTimer may determine (assume) how long the MAC entity of the terminal has been uplink time-aligned with the associated LTM candidate cell(s). The value of the TimeAlignmentTimer may be set by the base station to the terminal via RRC signaling, and may be set in time units (ms), slot units (number of slots), or infinite. The TimeAlignmentTimer may be set per LTM candidate cell and may be operated per LTM candidate cell. The TimeAlignmentTimer may utilize an existing TimeAlignmentTimer (TAT) for the LTM candidate cell, or a separate ltm-TimeAlignmentTimer (ltm-TAT) for the LTM candidate cell may be introduced.
[0573] According to one embodiment of the present disclosure, a terminal that receives a TA value (i.e., TAC) for an LTM candidate cell via RAR or MAC CE according to the above embodiment may apply the TA value to the corresponding LTM candidate cell and start a corresponding time alignment timer. When the time alignment timer starts, the time alignment timer becomes a running state.
[0574] According to one embodiment of the present disclosure, before the time alignment timer starts and expires (i.e., while it is running), a terminal that receives a TA value (i.e., TAC) for an LTM candidate cell via RAR or MAC CE according to the above embodiment may apply the TA value to the corresponding LTM candidate cell and restart the corresponding time alignment timer. That is, the time alignment timer value that was running may be initialized and the time alignment timer may be started again so that the time alignment timer becomes a running state.
[0575] According to one embodiment of the present disclosure, when the time alignment timer for a specific LTM candidate cell has expired after (re)started and time has elapsed (or is nearing expiration, which may be defined as the case where X% of the time alignment timer setting value set by the network to the terminal remains; the value of X may be predefined or set / instructed), the base station may perform an operation to enable the terminal to obtain a TA value again. That is, the base station may transmit a PDCCH order to the terminal to cause the terminal to transmit a PRACH preamble to the specific candidate cell.
[0576] According to one embodiment of the present disclosure, when the time alignment timer for an LTM candidate cell expires and the conditions for a set handover are satisfied, a handover operation to transmit a PRACH preamble to the LTM candidate cell can be initiated.
[0577] According to one embodiment of the present disclosure, while the time alignment timer for an LTM candidate cell is running, if a set handover condition is satisfied, the terminal may start a RACH-less handover operation. That is, the terminal does not send a PRACH preamble to the LTM candidate cell. The terminal may send a Handover Complete message to the LTM candidate cell that satisfied the handover condition as a sign that the 'RACH-less handover' operation has been completed.
[0578] According to one embodiment of the present disclosure, when a plurality of LTM candidate cells satisfy a set handover condition and the time alignment timers of some of the plurality of LTM candidate cells have expired, the LTM candidate cells whose time alignment timers have expired may have a lower priority compared to the candidate cells whose time alignment timers have not expired. That is, when a plurality of LTM candidate cells satisfy a set handover condition and the time alignment timers of some of the plurality of LTM candidate cells have expired, the terminal may perform an LTM handover to one of the LTM candidate cells that satisfy the set handover condition and whose time alignment timers have not expired (running).
[0579] FIG. 25 illustrates an example of operation related to a time alignment timer in a (conditional) LTM according to one embodiment of the present disclosure. The flowchart of FIG. 25 illustrates an exemplary method that can be implemented according to the principles of the present disclosure, and various modifications may be made to the method illustrated in the flowchart. For example, although illustrated as a series of steps, the various steps in each figure may overlap, occur in parallel, occur in a different order, or occur multiple times. In other examples, steps may be omitted or replaced with other steps.
[0580] Referring to FIG. 25, the terminal receives a PDCCH order transmitted by the base station and can transmit a PRACH preamble to the LTM candidate cell indicated by the PDCCH order (2510). The terminal can obtain a TA value for the LTM candidate cell according to the above-described embodiment (2520). The terminal can start a TimeAlignmentTimer (TAT) for the LTM candidate cell (2530). The terminal can perform a conditional LTM handover to an LTM candidate cell that satisfies a condition among the running LTM candidate cell(s) whose TAT has not expired (2540).
[0581] According to one embodiment of the present disclosure, a terminal that transmits a PRACH preamble to a candidate cell indicated by a 'PDCCH order' may perform an operation to receive a DCI format 1_0 with a CRC scrambled to RA-RNTI from a source cell (a currently connected cell, a cell that transmitted the 'PDCCH order') during a 'RAR window'. According to one embodiment of the present disclosure, the value of the 'RAR window' (e.g., ra-ResponseWindow) may be set by the station to the terminal for RRC signaling, etc. According to one embodiment of the present disclosure, the value of the 'RAR window' may correspond to the number of slots.
[0582] According to one embodiment of the present disclosure, a terminal with a conditional LTM configured can perform an operation to receive the DCI format 1_0 while the 'RAR window' is valid (running) without ignoring the 'RAR window' configuration value. According to one embodiment of the present disclosure, the 'RAR window' configuration value is a configuration value corresponding to the ra-ResponseWindow parameter, which may be within the rach-ConfigGeneric parameter, and the rach-ConfigGeneric parameter may be within the EarlyUL-SyncConfig configuration IE (Information Element).
[0583] According to one embodiment of the present disclosure, a terminal configured with a conditional LTM can start the 'RAR window' after transmitting a PRACH preamble via a PDCCH order. According to one embodiment of the present disclosure, the 'RAR window' value can be configured per LTM candidate cell. That is, it can be LTM candidate cell specific. Accordingly, according to one embodiment of the present disclosure, the terminal receives a PDCCH order commanding the transmission of a PRACH preamble to an LTM candidate cell, checks the 'RAR window' value of the configuration corresponding to the LTM candidate cell, and can start the checked 'RAR window'. The start of the 'RAR window' may be at the first PDCCH monitoring occasion after the completion of the transmission of the PRACH preamble, and there may be at least a certain time interval between the time of completion of the transmission of the PRACH preamble and the time of PDCCH monitoring. The time interval may be at least one symbol.
[0584] According to one embodiment of the present disclosure, a combination of some or all of the aforementioned embodiments may be performed by a terminal. According to one embodiment of the present disclosure, a combination of some or all of the aforementioned embodiments may be performed by a base station.
[0585] FIG. 26 is a drawing illustrating the structure of a terminal according to one embodiment of the present disclosure.
[0586] Referring to FIG. 26, the terminal may include a transceiver (2610), a control unit (processor) (2620), and a memory (storage unit) (2330). In the present disclosure, the control unit may be defined as a circuit or an application-specific integrated circuit or at least one processor.
[0587] The transceiver (2610) can transmit and receive signals with other network entities. The transceiver (2610) can, for example, transmit or receive a data channel. The transceiver (2610) can, for example, transmit or receive a control channel. The transceiver (2610) can, for example, transmit or receive an RRC message.
[0588] The control unit (2620) can control the overall operation of the terminal according to the embodiment proposed in the present disclosure. For example, the control unit (2620) can control the signal flow between each block to perform operations according to the flowchart described above. For example, the control unit (2620) receives a setting related to a conditional LTM (layer 1 / layer 2 (L1 / L2) triggered mobility) through upper layer signaling, receives a PDCCH (physical downlink control channel) order that triggers a PRACH (physical random access channel) transmission (the PDCCH order includes a field indicating an LTM candidate cell related to the conditional LTM), transmits a PRACH preamble to the LTM candidate cell via PRACH, monitors the PDCCH (physical downlink control channel) for the RAR while the RAR (random access response) window is running, receives the RAR via the PDSCH (physical downlink shared channel) based on the PDCCH, identifies that the TA (timing advance) value included in the RAR is for the LTM candidate cell, and the LTM The overall operation of the terminal can be controlled to start the TAT (time alignment timer) associated with the candidate cell.
[0589] In addition to this, the operation of the terminal described above can be controlled by the control unit (2620).
[0590] The memory (2630) can store at least one of the information transmitted and received through the transmission and reception unit (2610) and the information generated through the control unit (2320).
[0591] FIG. 27 is a drawing illustrating the structure of a base station according to one embodiment of the present disclosure.
[0592] Referring to FIG. 27, the base station may include a transceiver (2710), a control unit (processor) (2720), and a memory (2730). In the present disclosure, the control unit may be defined as a circuit or an application-specific integrated circuit or at least one processor.
[0593] The transceiver (2710) can transmit and receive signals with other network entities. The transceiver (2710) can transmit and receive data channels, for example. The transceiver (2710) can transmit or receive control channels, for example. The transceiver (2710) can transmit or receive RRC messages, for example.
[0594] The control unit (2720) can control the overall operation of the base station according to the embodiment proposed in the present disclosure. For example, the control unit (2720) can control the signal flow between each block to perform operations according to the flowchart described above. For example, the control unit (2720) transmits a setting related to a conditional LTM (layer 1 / layer 2 (L1 / L2) triggered mobility) through upper layer signaling, transmits a PDCCH (physical downlink control channel) order that triggers a PRACH (physical random access channel) transmission (the PDCCH order includes a field indicating an LTM candidate cell related to the conditional LTM), receives a PRACH preamble from the LTM candidate cell via PRACH, transmits a PDCCH (physical downlink control channel) for a RAR while a RAR (random access response) window is running, transmits the RAR via a PDSCH (physical downlink shared channel) (the TA (timing advance) value included in the RAR is for the LTM candidate cell), and transmits a TAT (time) related to the LTM candidate cell. The overall operation of the base station can be controlled to start the alignment timer.
[0595] In addition to this, the operation of the base station described above can be controlled by the control unit (2720).
[0596] The storage unit (2730) can store at least one of the information transmitted and received through the transmission and reception unit (2710) and the information generated through the control unit (2720).
[0597] Meanwhile, the order of description in the drawings illustrating the method of the present disclosure does not necessarily correspond to the order of execution, and the order of execution may be changed or executed in parallel.
[0598] Alternatively, drawings describing the method of the present disclosure may omit some components and include only some components to the extent that the essence of the present disclosure is not impaired.
[0599] Additionally, the method of the present disclosure may be implemented by combining some or all of the contents included in each embodiment to the extent that it does not impair the essence of the present disclosure.
[0600] Methods according to the claims or embodiments described in the specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.
[0601] When implemented in software, a computer-readable storage medium may be provided for storing one or more programs (software modules). One or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. One or more programs include instructions that cause the electronic device to execute methods according to the claims or embodiments described in the specification of this disclosure.
[0602] Such programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, ROM (Read Only Memory), Electrically Erasable Programmable Read Only Memory (EEPROM), magnetic disc storage devices, Compact Disc-ROM (CD-ROM), Digital Versatile Discs (DVDs), or other forms of optical storage devices, magnetic cassettes. Alternatively, they may be stored in memory composed of some or all of these. Additionally, each constituent memory may include multiple units.
[0603] Additionally, the program may be stored on an attachable storage device accessible via a communication network such as the Internet, Intranet, Local Area Network (LAN), Wide LAN (WLAN), or Storage Area Network (SAN), or a combination thereof. Such a storage device may be connected to a device performing an embodiment of the present disclosure through an external port. Additionally, a separate storage device on a communication network may be connected to a device performing an embodiment of the present disclosure.
[0604] In the specific embodiments of the present disclosure described above, the components included in the embodiments are expressed in a singular or plural form according to the specific embodiments presented. However, the singular or plural expression is selected to suit the situation presented for convenience of explanation, and the present disclosure is not limited to singular or plural components; even if a component is expressed in the plural form, it may be composed of a singular form, and even if a component is expressed in the singular form, it may be composed of a plural form.
[0605] Meanwhile, the embodiments of the present disclosure disclosed in this specification and drawings are merely specific examples provided to facilitate the explanation of the technical content of the present disclosure and to aid in understanding the present disclosure, and are not intended to limit the scope of the present disclosure. That is, it is obvious to those skilled in the art that other variations based on the technical concept of the present disclosure are possible. Furthermore, each of the above embodiments may be combined and operated as needed. For example, a base station and a terminal may be operated by combining parts of one embodiment of the present disclosure with parts of another embodiment. For example, a base station and a terminal may be operated by combining parts of the first embodiment and the second embodiment of the present disclosure. In addition, other variations based on the technical concept of the above embodiments may be implemented in other systems, such as FDD LTE systems, TDD LTE systems, 5G or NR systems.
[0606] Meanwhile, the order of description in the drawings illustrating the method of the present disclosure does not necessarily correspond to the order of execution, and the order of execution may be changed or executed in parallel.
[0607] Alternatively, drawings describing the method of the present disclosure may omit some components and include only some components to the extent that the essence of the present disclosure is not impaired.
[0608] Additionally, the method of the present disclosure may be implemented by combining some or all of the contents included in each embodiment to the extent that it does not impair the essence of the present disclosure.
[0609] Various embodiments of the present disclosure have been described above. The foregoing description of the present disclosure is for illustrative purposes only and is not limited to the embodiments disclosed. Those skilled in the art will understand that other specific forms can be easily modified without altering the technical spirit or essential features of the present disclosure. The scope of the present disclosure is defined by the claims set forth below rather than by the foregoing detailed description, and all modifications or variations derived from the meaning and scope of the claims and equivalent concepts should be interpreted as being included within the scope of the present disclosure.
Claims
1. A method performed by a terminal in a communication system, A step of receiving a setting related to a conditional LTM (layer 1 / layer 2 (L1 / L2) triggered mobility) through upper layer signaling; A step of receiving a PDCCH (physical downlink control channel) order that triggers a PRACH (physical random access channel) transmission, wherein the PDCCH order includes a field indicating an LTM candidate cell associated with the conditional LTM; A step of transmitting a PRACH preamble to the above LTM candidate cell via PRACH; A step of monitoring the PDCCH (physical downlink control channel) for the RAR while the RAR (random access response) window is running; A step of receiving the RAR through the PDSCH (physical downlink shared channel) based on the above PDCCH; A step of identifying that the TA (timing advance) value included in the above RAR is for the above LTM candidate cell; and A method comprising the step of starting a TAT (time alignment timer) associated with the above LTM candidate cell.
2. In Paragraph 1, The above PDCCH includes DCI (downlink control information) that schedules the above PDSCH, and The CRC (cyclic redundancy check) for the above DCI is scrambled into RA-RNTI (random access-radio network temporary identifier), and It is identified based on the RA-RNTI that the TA value included in the above RAR is for the above LTM candidate cell, and The initialization of the scrambling sequence for the above PDSCH is based on the identifier of the source cell associated with the RA-RNTI and the conditional LTM to which the above PDSCH is transmitted, and The above RA-RNTI satisfies the following Equation 1 or Equation 2, and [Mathematical Formula 1] RA-RNTI = 1 + s_id + 14 × t_id + 14 × 80 × f_id + 14 × 80 × 8 × ul_carrier_id +14 × 80 × 8 × 2 × ltm-CandidateId, [Mathematical Formula 2] RA-RNTI = 1 + s_id + 14 × t_id + 14 × 80 × f_id + 14 × 80 × 8 × ul_carrier_id +14 × 80 × 8 × 2 × Cell_indicator, The above s_id is the first OFDM (othogonal frequency division multiplexing) symbol index of the PRACH occasion in which the above PRACH preamble was transmitted, and The above t_id is the index of the first slot of the PRACH opportunity within the system frame in which the above PRACH preamble was transmitted, and The above f_id is the frequency axis index of the PRACH opportunity to which the above PRACH preamble was transmitted, and The above ul_carrier_id is the index of the uplink carrier to which the above PRACH preamble was transmitted, and The above ltm-CandidateId is the index of the cell to which the above PRACH preamble was transmitted, corresponding to a value for the index of one or more LTM candidate cells included in the settings associated with the above LTM, and A method in which the above Cell_indicator is the index of the cell to which the above PRACH preamble is transmitted, corresponding to the value for the field indicating the above LTM candidate cell.
3. In Paragraph 1, The above RAR includes a field associated with the cell corresponding to the above TA value, and The field associated with the cell corresponds to a value for an index of one or more LTM candidate cells included in the settings associated with the LTM, or corresponds to a value for a field indicating the LTM candidate cell, and A method in which the TA value included in the above RAR is identified as being for the above LTM candidate cell based on a field associated with the cell corresponding to the above TA value.
4. In Paragraph 1, It is assumed that the PDCCH DM-RS (demodulation reference signal) for the PDCCH for the above RAR is quasi-co-located with a specific DL RS (downlink reference signal) and QCL, and It is assumed that the PDSCH DM-RS for the above PDSCH is the above PDCCH DM-RS and QCL, and The specific DL RS above includes a PDCCH DM-RS for the PDCCH command, an SS / PBCH (synchronization signal / physical broadcast channel) block or a CSI-RS (channel state information reference signal) associated with the PRACH preamble, and The index of the above SS / PBCH block is identified based on the above PDCCH command, and the above SS / PBCH block is received from the above LTM candidate cell, and A method in which an index of a CSI-RS resource corresponding to the above CSI-RS is identified based on the above PDCCH command and the above CSI-RS is received from the above LTM candidate cell.
5. In Paragraph 1, If a conditional LTM condition related to the LTM candidate cell is satisfied while the above TAT is running, the method further includes the step of performing an operation related to RACH-less-based mobility to the LTM candidate cell based on the TA value. The above conditional LTM condition is a method included in one or more conditional LTM conditions included in the settings associated with the above LTM.
6. In a terminal of a communication system, Transmitter / receiver; and It includes a processor connected to the above-mentioned transceiver, and the processor is: Receive settings related to conditional LTM (layer 1 / layer 2 (L1 / L2) triggered mobility) through upper layer signaling; Receive a PDCCH (physical downlink control channel) order that triggers a PRACH (physical random access channel) transmission, said PDCCH order including a field indicating an LTM candidate cell associated with said conditional LTM; Transmit the PRACH preamble to the above LTM candidate cell via PRACH; Monitor the PDCCH (physical downlink control channel) for RAR while the RAR (random access response) window is running; Receiving the RAR via the PDSCH (physical downlink shared channel) based on the above PDCCH; Identifying that the TA (timing advance) value included in the above RAR is for the above LTM candidate cell; and A terminal configured to start the TAT (time alignment timer) associated with the above LTM candidate cell.
7. In Paragraph 6, The above PDCCH includes DCI (downlink control information) that schedules the above PDSCH, and The CRC (cyclic redundancy check) for the above DCI is scrambled into RA-RNTI (random access-radio network temporary identifier), and It is identified based on the RA-RNTI that the TA value included in the above RAR is for the above LTM candidate cell, and The initialization of the scrambling sequence for the above PDSCH is based on the identifier of the source cell associated with the RA-RNTI and the conditional LTM to which the above PDSCH is transmitted, and The above RA-RNTI satisfies the following Equation 1 or Equation 2, and [Mathematical Formula 1] RA-RNTI = 1 + s_id + 14 × t_id + 14 × 80 × f_id + 14 × 80 × 8 × ul_carrier_id +14 × 80 × 8 × 2 × ltm-CandidateId, [Mathematical Formula 2] RA-RNTI = 1 + s_id + 14 × t_id + 14 × 80 × f_id + 14 × 80 × 8 × ul_carrier_id +14 × 80 × 8 × 2 × Cell_indicator, The above s_id is the first OFDM (othogonal frequency division multiplexing) symbol index of the PRACH occasion in which the above PRACH preamble was transmitted, and The above t_id is the index of the first slot of the PRACH opportunity within the system frame in which the above PRACH preamble was transmitted, and The above f_id is the frequency axis index of the PRACH opportunity to which the above PRACH preamble was transmitted, and The above ul_carrier_id is the index of the uplink carrier to which the above PRACH preamble was transmitted, and The above ltm-CandidateId is the index of the cell to which the above PRACH preamble was transmitted, corresponding to a value for the index of one or more LTM candidate cells included in the settings associated with the above LTM, and The above Cell_indicator is a terminal, which is the index of the cell to which the above PRACH preamble was transmitted, corresponding to the value for the field indicating the above LTM candidate cell.
8. In Paragraph 6, The above RAR includes a field associated with the cell corresponding to the above TA value, and The field associated with the cell corresponds to a value for an index of one or more LTM candidate cells included in the settings associated with the LTM, or corresponds to a value for a field indicating the LTM candidate cell, and A terminal in which the TA value included in the above RAR is for the above LTM candidate cell, identified based on a field associated with the cell corresponding to the above TA value.
9. In Paragraph 6, It is assumed that the PDCCH DM-RS (demodulation reference signal) for the PDCCH for the above RAR is quasi-co-located with a specific DL RS (downlink reference signal) and QCL, and It is assumed that the PDSCH DM-RS for the above PDSCH is the above PDCCH DM-RS and QCL, and The specific DL RS above includes a PDCCH DM-RS for the PDCCH command, an SS / PBCH (synchronization signal / physical broadcast channel) block or a CSI-RS (channel state information reference signal) associated with the PRACH preamble, and The index of the above SS / PBCH block is identified based on the above PDCCH command, and the above SS / PBCH block is received from the above LTM candidate cell, and The index of the CSI-RS resource corresponding to the above CSI-RS is identified based on the above PDCCH command, and the CSI-RS is received from the above LTM candidate cell, terminal.
10. In Paragraph 6, The processor is configured to perform an operation related to RACH-less-based mobility to the LTM candidate cell based on the TA value when a conditional LTM condition related to the LTM candidate cell is satisfied while the TAT is running, and The above conditional LTM condition is a terminal included in one or more conditional LTM conditions included in the settings associated with the above LTM.
11. In a method performed by a base station in a communication system, A step of transmitting settings related to conditional LTM (layer 1 / layer 2 (L1 / L2) triggered mobility) through upper layer signaling; A step of transmitting a PDCCH (physical downlink control channel) order that triggers the transmission of a PRACH (physical random access channel), wherein the PDCCH order includes a field indicating an LTM candidate cell associated with the conditional LTM; A step of receiving a PRACH preamble through PRACH in the above LTM candidate cell; A step of transmitting a PDCCH (physical downlink control channel) for RAR while a RAR (random access response) window is running; A step of transmitting the above RAR through a PDSCH (physical downlink shared channel), wherein the TA (timing advance) value included in the above RAR is for the above LTM candidate cell; and A method comprising the step of starting a TAT (time alignment timer) associated with the above LTM candidate cell.
12. In Paragraph 11, The above PDCCH includes DCI (downlink control information) that schedules the above PDSCH, and The CRC (cyclic redundancy check) for the above DCI is scrambled into RA-RNTI (random access-radio network temporary identifier), and It is indicated based on the RA-RNTI that the TA value included in the above RAR is for the above LTM candidate cell, and The initialization of the scrambling sequence for the above PDSCH is based on the identifier of the source cell associated with the RA-RNTI and the conditional LTM to which the above PDSCH is transmitted, and The above RA-RNTI satisfies the following Equation 1 or Equation 2, and [Mathematical Formula 1] RA-RNTI = 1 + s_id + 14 × t_id + 14 × 80 × f_id + 14 × 80 × 8 × ul_carrier_id +14 × 80 × 8 × 2 × ltm-CandidateId, [Mathematical Formula 2] RA-RNTI = 1 + s_id + 14 × t_id + 14 × 80 × f_id + 14 × 80 × 8 × ul_carrier_id +14 × 80 × 8 × 2 × Cell_indicator, The above s_id is the first OFDM (othogonal frequency division multiplexing) symbol index of the PRACH occasion in which the above PRACH preamble was received, and The above t_id is the index of the first slot of the PRACH opportunity within the system frame in which the above PRACH preamble was received, and The above f_id is the frequency axis index of the PRACH opportunity in which the above PRACH preamble was received, and The above ul_carrier_id is the index of the uplink carrier that received the above PRACH preamble, and The above ltm-CandidateId is the index of the cell to which the above PRACH preamble was received, corresponding to a value for the index of one or more LTM candidate cells included in the settings associated with the above LTM, and A method in which the above Cell_indicator is the index of the cell in which the above PRACH preamble is received, corresponding to the value for the field indicating the above LTM candidate cell.
13. In Paragraph 11, The above RAR includes a field associated with the cell corresponding to the above TA value, and The field associated with the cell corresponds to a value for an index of one or more LTM candidate cells included in the settings associated with the LTM, or corresponds to a value for a field indicating the LTM candidate cell, and A method in which the TA value included in the above RAR is for the above LTM candidate cell is indicated based on a field associated with the cell corresponding to the above TA value.
14. In Paragraph 11, It is assumed that the PDCCH DM-RS (demodulation reference signal) for the PDCCH for the above RAR is quasi-co-located with a specific DL RS (downlink reference signal) and QCL, and It is assumed that the PDSCH DM-RS for the above PDSCH is the above PDCCH DM-RS and QCL, and The specific DL RS above includes a PDCCH DM-RS for the PDCCH command, an SS / PBCH (synchronization signal / physical broadcast channel) block or a CSI-RS (channel state information reference signal) associated with the PRACH preamble, and The index of the above SS / PBCH block is indicated based on the above PDCCH command, and the above SS / PBCH block is transmitted from the above LTM candidate cell, and A method in which an index of a CSI-RS resource corresponding to the above CSI-RS is identified based on the above PDCCH command and the above CSI-RS is transmitted from the above LTM candidate cell.
15. In a base station of a communication system, Transmitter / receiver; and It includes a processor connected to the above-mentioned transceiver, and the processor is: Transmit settings related to conditional LTM (layer 1 / layer 2 (L1 / L2) triggered mobility) through upper layer signaling; Transmitting a PDCCH (physical downlink control channel) order that triggers a PRACH (physical random access channel) transmission, said PDCCH order including a field indicating an LTM candidate cell associated with said conditional LTM; Receive the PRACH preamble from the above LTM candidate cell via PRACH; Transmit the PDCCH (physical downlink control channel) for the RAR while the RAR (random access response) window is running; The above RAR is transmitted via PDSCH (physical downlink shared channel), and the TA (timing advance) value included in the above RAR is for the above LTM candidate cell; and A base station configured to start the TAT (time alignment timer) associated with the above LTM candidate cell.