Method and apparatus for random access in sbfd environment

Abstract

This method for a terminal may comprise the steps of: receiving downlink control information (DCI) including a PDCCH order from a base station; determining a random access channel (RACH) occasion (RO) type on the basis of information included in the DCI; and transmitting a preamble to the base station in an RO according to the determined RO type.

Description

Method and apparatus for random access in an SBFD environment

[0001] The present disclosure relates to random access technology of a mobile communication system, and more specifically, to a method and apparatus for performing a random access procedure in an environment where a subband full duplex (SBFD) operation is performed.

[0002] Communication networks (e.g., 5G communication networks, 6G communication networks, etc.) are being developed to provide communication services that are improved over existing communication networks (e.g., LTE (long term evolution), LTE-A (advanced), etc.). 5G communication networks (e.g., NR (new radio) communication networks) can support frequency bands above 6 GHz as well as frequency bands below 6 GHz. That is, 5G communication networks can support the FR1 band and / or FR2 band. 5G communication networks can support a wider variety of communication services and scenarios compared to LTE communication networks. For example, usage scenarios for 5G communication networks may include eMBB (enhanced Mobile BroadBand), URLLC (Ultra Reliable Low Latency Communication), mMTC (massive Machine Type Communication), etc.

[0003] 6G communication networks can support a wider variety of communication services and scenarios compared to 5G communication networks. 6G communication networks can meet the requirements for ultra-high performance, ultra-bandwidth, ultra-spatial, ultra-precision, ultra-intelligence, and / or ultra-reliability. 6G communication networks can support a wide range of frequency bands and can be applied to various usage scenarios (e.g., terrestrial communication, non-terrestrial communication, sidelink communication, etc.).

[0004] Meanwhile, as part of the enhancement of the TDD system, 3GPP is proceeding with the standardization of subband full duplex (SBFD) technology, which allows a base station to simultaneously perform downlink (DL) signal transmission and uplink (UL) signal reception using non-overlapping resources in the frequency domain within the TDD band.

[0005] Additional RACH (random access channel) occupations (ROs) for terminals supporting SBFD operation may be configured in SBFD symbols for which subbands for SBFD operation are configured. In this case, solutions are required for legacy ROs for legacy terminals that do not support SBFD operation and for additional ROs, methods for indicating and / or determining the RO type for performing the RACH procedure, and solutions for overlapping issues between legacy ROs and additional ROs.

[0006] The objective of the present disclosure to solve the above-mentioned problems is to provide a method and apparatus for performing a random access procedure in an environment where a subband full duplex (SBFD) operation is performed.

[0007] A method of a terminal according to embodiments of the present disclosure for achieving the above objective may include: receiving downlink control information (DCI) including a PDCCH order from a base station; determining a random access channel (RACH) occupancy (RO) type based on the information included in the DCI; and transmitting a preamble from the RO according to the determined RO type to the base station.

[0008] The above RO type may be a legacy RO or an additional RO.

[0009] The above RO type may be indicated by a field included in the DCI, by reserved bit(s) included in the DCI, or by a radio network temporary identifier (RNTI) scrambled into the CRC of the DCI.

[0010] The field included in the above DCI may be a frequency-domain resource assignment field or an RO mask index field.

[0011] The above method further includes a step of receiving information about subgroups of partitioned preambles prior to the step of receiving the DCI, and the RO type may be determined as the RO type corresponding to the subgroup to which the preamble index indicated in the DCI belongs.

[0012] The above subgroups may include a subgroup of preambles for a CBRA (contention-based random access) procedure for legacy ROs, a subgroup of preambles for a CFRA (contention-free random access) procedure for legacy ROs, a subgroup of preambles for a CBRA procedure for additional ROs, and a subgroup of preambles for a CFRA procedure for additional ROs.

[0013] The above subgroups may include a subgroup of preambles for CBRA procedures for legacy ROs and additional ROs, a subgroup of preambles for CFRA procedures for legacy ROs, and a subgroup of preambles for CBRA procedures for additional ROs.

[0014] A method of a base station according to embodiments of the present disclosure for achieving the above objective comprises: transmitting downlink control information (DCI) including a PDCCH order to a terminal; and receiving a preamble from the terminal, wherein the preamble may be received at an RO according to a random access channel (RO) type determined based on information included in the DCI.

[0015] The above RO type may be a legacy RO or an additional RO.

[0016] The above RO type may be indicated by a field included in the DCI, by reserved bit(s) included in the DCI, or by a radio network temporary identifier (RNTI) scrambled into the CRC of the DCI.

[0017] The field included in the above DCI may be a frequency-domain resource assignment field or an RO mask index field.

[0018] The above method further includes a step of transmitting information about subgroups of partitioned preambles to the terminal prior to the step of transmitting the DCI, and the RO type may be determined as an RO type corresponding to the subgroup to which the preamble index indicated in the DCI belongs.

[0019] The above subgroups may include a subgroup of preambles for a CBRA (contention-based random access) procedure for legacy ROs, a subgroup of preambles for a CFRA (contention-free random access) procedure for legacy ROs, a subgroup of preambles for a CBRA procedure for additional ROs, and a subgroup of preambles for a CFRA procedure for additional ROs.

[0020] The above subgroups may include a subgroup of preambles for CBRA procedures for legacy ROs and additional ROs, a subgroup of preambles for CFRA procedures for legacy ROs, and a subgroup of preambles for CBRA procedures for additional ROs.

[0021] A terminal according to embodiments of the present disclosure for achieving the above objective comprises at least one processor, and the at least one processor may enable the terminal to perform the steps of: receiving downlink control information (DCI) including a PDCCH order from a base station; determining a random access channel (RACH) occupancy (RO) type based on the information included in the DCI; and transmitting a preamble from the RO according to the determined RO type to the base station.

[0022] The above RO type may be a legacy RO or an additional RO.

[0023] The above RO type may be indicated by a field included in the DCI, by reserved bit(s) included in the DCI, or by a radio network temporary identifier (RNTI) scrambled into the CRC of the DCI.

[0024] The above at least one processor enables the terminal to additionally perform the step of receiving information about subgroups of partitioned preambles prior to the step of receiving the DCI, and the RO type may be determined as an RO type corresponding to the subgroup to which the preamble index indicated in the DCI belongs.

[0025] The above subgroups may include a subgroup of preambles for a CBRA (contention-based random access) procedure for legacy ROs, a subgroup of preambles for a CFRA (contention-free random access) procedure for legacy ROs, a subgroup of preambles for a CBRA procedure for additional ROs, and a subgroup of preambles for a CFRA procedure for additional ROs.

[0026] The above subgroups may include a subgroup of preambles for CBRA procedures for legacy ROs and additional ROs, a subgroup of preambles for CFRA procedures for legacy ROs, and a subgroup of preambles for CBRA procedures for additional ROs.

[0027] According to embodiments of the present disclosure, various methods may be provided to effectively distinguish and indicate legacy ROs and additional ROs in a PDCCH order-based RACH procedure. Accordingly, the terminal can select an appropriate RO type for the situation and transmit a preamble, and consistent operation is possible even in situations of RO type overlap or collision. Accordingly, the methods according to the present disclosure minimize control signal collisions between the terminal and the base station and enable stable RACH procedure execution even in situations such as beam failure recovery. Furthermore, when the terminal initiates a RACH procedure, according to embodiments of the present disclosure, the terminal can determine the RO type for preamble transmission by considering additional conditions (e.g., RSRP threshold, terminal state, time conditions, etc.). Accordingly, by selecting an appropriate RO type, the terminal can reduce the probability of collision and increase resource utilization efficiency. Consequently, when the methods according to the present disclosure are applied, the connection success rate of the terminal and the efficiency of network resources can be significantly improved in an NR SBFD environment.

[0028] FIG. 1 is a conceptual diagram illustrating a first embodiment of a communication system.

[0029] FIG. 2 is a block diagram illustrating a first embodiment of a communication node constituting a communication system.

[0030] FIG. 3 is a block diagram illustrating a first embodiment of communication nodes performing communication.

[0031] FIG. 4a is a block diagram illustrating a first embodiment of a transmission path.

[0032] FIG. 4b is a block diagram illustrating a first embodiment of a receiving path.

[0033] FIG. 5 is a conceptual diagram illustrating a first embodiment of a system frame in a communication system.

[0034] FIG. 6 is a conceptual diagram illustrating a first embodiment of a subframe in a communication system.

[0035] FIG. 7 is a conceptual diagram illustrating a first embodiment of a slot in a communication system.

[0036] FIG. 8 is a conceptual diagram illustrating a first embodiment of a time-frequency resource in a communication system.

[0037] FIG. 9 is a conceptual diagram illustrating a preamble division according to an embodiment of the present disclosure.

[0038] FIG. 10 is a conceptual diagram illustrating various cases of preamble division according to an embodiment of the present disclosure.

[0039] FIG. 11 is a flowchart for explaining embodiments of the present invention.

[0040] The present disclosure is capable of various modifications and may have various embodiments, and specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the present disclosure to specific embodiments and should be understood to include all modifications, equivalents, and substitutions that fall within the spirit and scope of the present disclosure.

[0041] Terms such as "first," "second," etc., may be used to describe various components, but said components should not be limited by said terms. Such terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present disclosure, the first component may be named the second component, and similarly, the second component may be named the first component. The term "and / or" may mean a combination of a plurality of related described items or any of a plurality of related described items.

[0042] In the present disclosure, "at least one of A and B" may mean "at least one of A or B" or "at least one of one or more combinations of A and B". Additionally, in the present disclosure, "at least one of A and B" may mean "at least one of A or B" or "at least one of one or more combinations of A and B".

[0043] In the present disclosure, (re)transmission may mean "transmission," "retransmission," or "transmission and retransmission"; (re)setting may mean "setting," "resetting," or "setting and resetting"; (re)connection may mean "connection," "reconnection," or "connection and reconnection"; and (re)connection may mean "connection," "reconnection," or "connection and reconnection".

[0044] When it is stated that one component is "connected" or "connected" to another component, it should be understood that while it may be directly connected or connected to that other component, there may also be other components in between. On the other hand, when it is stated that one component is "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between.

[0045] The terms used in this disclosure are used merely to describe specific embodiments and are not intended to limit this disclosure. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this disclosure, terms such as “comprising” or “having” are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0046] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which this disclosure pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this disclosure.

[0047] Hereinafter, preferred embodiments of the present disclosure will be described in more detail with reference to the attached drawings. To facilitate overall understanding in describing the present disclosure, the same reference numerals are used for identical components in the drawings, and redundant descriptions of identical components are omitted. Operations according to combinations of embodiments, extensions of embodiments, and / or modifications of embodiments may be performed, as well as the embodiments explicitly described in the present disclosure. The performance of some operations may be omitted, and the order of operations may be changed.

[0048] In the embodiments, even when a method performed at a first communication node among the communication nodes (e.g., transmission or reception of a signal) is described, the corresponding second communication node may perform a method corresponding to the method performed at the first communication node (e.g., reception or transmission of a signal). That is, when the operation of a UE (user equipment) is described, the corresponding base station may perform an operation corresponding to the operation of the UE. Conversely, when the operation of a base station is described, the corresponding UE may perform an operation corresponding to the operation of the base station.

[0049] A base station may be referred to as Node B, evolved Node B, gNode B (next generation node B), gNB, device, apparatus, node, communication node, BTS (base transceiver station), RRH (radio remote head), TRP (transmission reception point), RU (radio unit), RSU (road side unit), radio transceiver, access point, access node, etc. A UE may be referred to as terminal, device, apparatus, node, communication node, end node, access terminal, mobile terminal, station, subscriber station, mobile station, portable subscriber station, OBU (on-broad unit), etc.

[0050] In the present disclosure, signaling may be at least one of upper-layer signaling, MAC signaling, or PHY (physical) signaling. A message used for upper-layer signaling may be referred to as an "upper-layer message" or an "upper-layer signaling message." A message used for MAC signaling may be referred to as a "MAC message" or a "MAC signaling message." A message used for PHY signaling may be referred to as a "PHY message" or a "PHY signaling message." Upper-layer signaling may refer to the transmission and reception operations of system information (e.g., MIB (master information block), SIB (system information block)) and / or RRC messages. MAC signaling may refer to the transmission and reception operations of MAC CE (control element). PHY signaling may refer to the transmission and reception operations of control information (e.g., DCI (downlink control information), UCI (uplink control information), SCI (sidelink control information)).

[0051] In the present disclosure, "setting an operation (e.g., a transmission operation)" may mean that "setting information for said operation (e.g., an information element, a parameter)" and / or "information directing the performance of said operation" is signaled. "Setting an information element (e.g., a parameter)" may mean that said information element is signaled. In the present disclosure, "signal and / or channel" may mean a signal, a channel, or "signal and channel," and "signal" may be used to mean "signal and / or channel."

[0052] The communication networks to which the embodiments are applied are not limited to those described below, and the embodiments may be applied to various communication networks (e.g., 4G communication networks, 5G communication networks, and / or 6G communication networks). Here, the term "communication network" may be used interchangeably with "communication system."

[0053] FIG. 1 is a conceptual diagram illustrating a first embodiment of a communication system.

[0054] Referring to FIG. 1, the communication system (100) may include a plurality of communication nodes (110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5, 130-6). Additionally, the communication system (100) may further include a core network (e.g., an S-GW (serving-gateway), a P-GW (PDN (packet data network)-gateway), and an MME (mobility management entity)). If the communication system (100) is a 5G communication system (e.g., a new radio (NR) system), the core network may include an AMF (access and mobility management function), a UPF (user plane function), an SMF (session management function), etc.

[0055] Multiple communication nodes (110 to 130) can support communication protocols defined in 3GPP (3rd generation partnership project) standards (e.g., LTE communication protocol, LTE-A communication protocol, NR communication protocol, etc.). Multiple communication nodes (110 to 130) can support CDMA (code division multiple access) technology, WCDMA (wideband CDMA) technology, TDMA (time division multiple access) technology, FDMA (frequency division multiple access) technology, OFDM (orthogonal frequency division multiplexing) technology, Filtered OFDM technology, CP (cyclic prefix)-OFDM technology, DFT-s-OFDM (discrete Fourier transform-spread-OFDM) technology, OFDMA (orthogonal frequency division multiple access) technology, SC (single carrier)-FDMA technology, NOMA (non-orthogonal multiple access) technology, GFDM (generalized frequency division multiplexing) technology, FBMC (filter bank multi-carrier) technology, UFMC (universal filtered multi-carrier) technology, SDMA (space division multiple access) technology, etc. Each of the multiple communication nodes may have the following structure.

[0056] FIG. 2 is a block diagram illustrating a first embodiment of a communication node constituting a communication system.

[0057] Referring to FIG. 2, the communication node (200) may include at least one processor (210), a memory (220), and a transceiver (230) that is connected to a network to perform communication. Additionally, the communication node (200) may further include an input interface device (240), an output interface device (250), a storage device (260), etc. Each component included in the communication node (200) may be connected by a bus (270) to communicate with one another.

[0058] The processor (210) can execute a program command stored in at least one of the memory (220) and the storage device (260). The processor (210) may mean a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which the methods according to embodiments of the present disclosure are performed. Each of the memory (220) and the storage device (260) may be composed of at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory (220) may be composed of at least one of read-only memory (ROM) and random access memory (RAM).

[0059] Referring again to FIG. 1, the communication system (100) may include a plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) and a plurality of terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6). Each of the first base station (110-1), the second base station (110-2), and the third base station (110-3) may form a macro cell. Each of the fourth base station (120-1) and the fifth base station (120-2) may form a small cell. The fourth base station (120-1), the third terminal (130-3), and the fourth terminal (130-4) may be located within the cell coverage of the first base station (110-1). The second terminal (130-2), the fourth terminal (130-4), and the fifth terminal (130-5) may be located within the cell coverage of the second base station (110-2). The fifth base station (120-2), the fourth terminal (130-4), the fifth terminal (130-5), and the sixth terminal (130-6) may be located within the cell coverage of the third base station (110-3). The first terminal (130-1) may be located within the cell coverage of the fourth base station (120-1). The sixth terminal (130-6) may be located within the cell coverage of the fifth base station (120-2).

[0060] Here, each of the multiple base stations (110-1, 110-2, 110-3, 120-1, 120-2) may be referred to as NB (NodeB), eNB (evolved NodeB), gNB, ABS (advanced base station), HR-BS (high reliability-base station), BTS (base transceiver station), radio base station, radio transceiver, access point, access node, RAS (radio access station), MMR-BS (mobile multihop relay-base station), RS (relay station), ARS (advanced relay station), HR-RS (high reliability-relay station), HNB (home NodeB), HeNB (home eNodeB), RSU (road side unit), RRH (radio remote head), TP (transmission point), TRP (transmission and reception point), etc.

[0061] Each of the multiple terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) may be referred to as UE (user equipment), TE (terminal equipment), AMS (advanced mobile station), HR-MS (high reliability-mobile station), terminal, access terminal, mobile terminal, station, subscriber station, mobile station, portable subscriber station, node, device, OBU (on board unit), etc.

[0062] Meanwhile, each of the multiple base stations (110-1, 110-2, 110-3, 120-1, 120-2) may operate in different frequency bands or in the same frequency band. Each of the multiple base stations (110-1, 110-2, 110-3, 120-1, 120-2) may be connected to each other via an ideal backhaul link or a non-ideal backhaul link, and may exchange information with each other via an ideal backhaul link or a non-ideal backhaul link. Each of the multiple base stations (110-1, 110-2, 110-3, 120-1, 120-2) may be connected to a core network via an ideal backhaul link or a non-ideal backhaul link. Each of the multiple base stations (110-1, 110-2, 110-3, 120-1, 120-2) can transmit a signal received from the core network to the corresponding terminal (130-1, 130-2, 130-3, 130-4, 130-5, 130-6), and can transmit a signal received from the corresponding terminal (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) to the core network.

[0063] In addition, each of the multiple base stations (110-1, 110-2, 110-3, 120-1, 120-2) can support MIMO transmission (e.g., SU (single user)-MIMO, MU (multi user)-MIMO, massive MIMO, etc.), CoMP (coordinated multipoint) transmission, carrier aggregation (CA) transmission, transmission in an unlicensed band, sidelink communication (e.g., D2D (device to device communication), ProSe (proximity services)), IoT (Internet of Things) communication, dual connectivity (DC), etc. Here, each of the plurality of terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) can perform an operation corresponding to the base station (110-1, 110-2, 110-3, 120-1, 120-2) and an operation supported by the base station (110-1, 110-2, 110-3, 120-1, 120-2). For example, the second base station (110-2) can transmit a signal to the fourth terminal (130-4) based on the SU-MIMO method, and the fourth terminal (130-4) can receive a signal from the second base station (110-2) based on the SU-MIMO method. Alternatively, the second base station (110-2) can transmit a signal to the fourth terminal (130-4) and the fifth terminal (130-5) based on the MU-MIMO method, and each of the fourth terminal (130-4) and the fifth terminal (130-5) can receive a signal from the second base station (110-2) by the MU-MIMO method.

[0064] Each of the first base station (110-1), the second base station (110-2), and the third base station (110-3) can transmit a signal to the fourth terminal (130-4) based on the CoMP method, and the fourth terminal (130-4) can receive a signal from the first base station (110-1), the second base station (110-2), and the third base station (110-3) by the CoMP method. Each of the multiple base stations (110-1, 110-2, 110-3, 120-1, 120-2) can transmit and receive signals based on the CA method with terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) within its cell coverage area. Each of the first base station (110-1), the second base station (110-2), and the third base station (110-3) can control sidelink communication between the fourth terminal (130-4) and the fifth terminal (130-5), and each of the fourth terminal (130-4) and the fifth terminal (130-5) can perform sidelink communication by controlling each of the second base station (110-2) and the third base station (110-3).

[0065] Meanwhile, communication nodes performing communication in a communication network may be configured as follows. The communication node shown in FIG. 3 may be a specific embodiment of the communication node shown in FIG. 2.

[0066] FIG. 3 is a block diagram illustrating a first embodiment of communication nodes performing communication.

[0067] Referring to FIG. 3, the first communication node (300a) and the second communication node (300b) may each be a base station or a UE. The first communication node (300a) may transmit a signal to the second communication node (300b). A transmission processor (311) included in the first communication node (300a) may receive data (e.g., a data unit) from a data source (310). The transmission processor (311) may receive control information from a controller (316). The control information may include at least one of system information, RRC setting information (e.g., information set by RRC signaling), MAC control information (e.g., MAC CE), or PHY control information (e.g., DCI, SCI).

[0068] The transmitting processor (311) can generate data symbol(s) by performing processing operations on data (e.g., encoding operations, symbol mapping operations, etc.). The transmitting processor (311) can generate control symbol(s) by performing processing operations on control information (e.g., encoding operations, symbol mapping operations, etc.). Additionally, the transmitting processor (311) can generate synchronization / reference symbol(s) for synchronization signals and / or reference signals.

[0069] The Tx MIMO processor (312) can perform spatial processing operations (e.g., precoding operations) on data symbol(s), control symbol(s), and / or synchronization / reference symbol(s). The output of the Tx MIMO processor (312) (e.g., a symbol stream) can be provided to modulators (MODs) included in transceivers (313a to 313t). The modulators (MODs) can perform processing operations on the symbol stream to generate modulated symbols and perform additional processing operations on the modulated symbols (e.g., analog conversion operations, amplification operations, filtering operations, up-conversion operations) to generate signals. The signals generated by the modulators (MODs) of the transceivers (313a to 313t) can be transmitted through antennas (314a to 314t).

[0070] Signals transmitted by the first communication node (300a) can be received at the antennas (364a to 364r) of the second communication node (300b). Signals received at the antennas (364a to 364r) can be provided to demodulators (DEMODs) included in the transceivers (363a to 363r). The demodulators (DEMODs) can obtain samples by performing processing operations on the signals (e.g., filtering, amplification, down-conversion, digital conversion). The demodulators (DEMODs) can obtain symbols by performing additional processing operations on the samples. The MIMO detector (362) can perform MIMO detection operations on the symbols. The receiving processor (361) can perform processing operations on the symbols (e.g., deinterleaving, decoding). The output of the receiving processor (361) can be provided to the data sink (360) and the controller (366). For example, data can be provided to the data sink (360), and control information can be provided to the controller (366).

[0071] Meanwhile, the second communication node (300b) can transmit a signal to the first communication node (300a). The transmission processor (368) included in the second communication node (300b) can receive data (e.g., a data unit) from the data source (367) and can generate data symbol(s) by performing a processing operation on the data. The transmission processor (368) can receive control information from the controller (366) and can generate control symbol(s) by performing a processing operation on the control information. Additionally, the transmission processor (368) can generate reference symbol(s) by performing a processing operation on a reference signal.

[0072] The Tx MIMO processor (369) can perform spatial processing operations (e.g., precoding operations) on data symbol(s), control symbol(s), and / or reference symbol(s). The output of the Tx MIMO processor (369) (e.g., a symbol stream) can be provided to modulators (MODs) included in transceivers (363a to 363t). The modulators (MODs) can perform processing operations on the symbol stream to generate modulated symbols and perform additional processing operations on the modulated symbols (e.g., analog conversion operations, amplification operations, filtering operations, up-conversion operations) to generate signals. The signals generated by the modulators (MODs) of the transceivers (363a to 363t) can be transmitted through antennas (364a to 364t).

[0073] Signals transmitted by the second communication node (300b) can be received at the antennas (314a to 314r) of the first communication node (300a). Signals received at the antennas (314a to 314r) can be provided to demodulators (DEMODs) included in the transceivers (313a to 313r). The demodulators (DEMODs) can obtain samples by performing processing operations on the signals (e.g., filtering operation, amplification operation, down-conversion operation, digital conversion operation). The demodulators (DEMODs) can obtain symbols by performing additional processing operations on the samples. The MIMO detector (320) can perform MIMO detection operations on the symbols. The receiving processor (319) can perform processing operations on the symbols (e.g., deinterleaving operation, decoding operation). The output of the receiving processor (319) can be provided to the data sink (318) and the controller (316). For example, data can be provided to the data sink (318), and control information can be provided to the controller (316).

[0074] The memories (315 and 365) may store data, control information, and / or program code. The scheduler (317) may perform scheduling operations for communication. The processors (311, 312, 319, 361, 368, 369) and controllers (316, 366) shown in FIG. 3 may be the processor (210) shown in FIG. 2 and may be used to perform the methods described in this disclosure.

[0075] FIG. 4a is a block diagram illustrating a first embodiment of a transmission path, and FIG. 4b is a block diagram illustrating a first embodiment of a reception path.

[0076] Referring to FIGS. 4a and 4b, a transmission path (410) may be implemented at a communication node that transmits a signal, and a reception path (420) may be implemented at a communication node that receives a signal. The transmission path (410) may include a channel coding and modulation block (411), an S-to-P (serial-to-parallel) block (512), an N IFFT (Inverse Fast Fourier Transform) block (413), a P-to-S (parallel-to-serial) block (414), a CP (cyclic prefix) addition block (415), and an UC (up-converter) (UC) (416). The reception path (420) may include a DC (down-converter) (421), a CP removal block (422), an S-to-P block (423), an N FFT block (424), a P-to-S block (425), and a channel decoding and demodulation block (426). Here, N can be a natural number.

[0077] Information bits in the transmission path (410) can be input to the channel coding and modulation block (411). The channel coding and modulation block (411) can perform coding operations (e.g., LDPC (low-density parity check) (LDPC) coding operations, polar coding operations, etc.) and modulation operations (e.g., QPSK (Quadrature Phase Shift Keying), QAM (Quadrature Amplitude Modulation), etc.) on the information bits. The output of the channel coding and modulation block (411) may be a sequence of modulation symbols.

[0078] The S-to-P block (412) can convert modulated symbols in the frequency domain into parallel symbol streams to generate N parallel symbol streams. N can be the IFFT size or the FFT size. The N IFFT block (413) can generate signals in the time domain by performing an IFFT operation on the N parallel symbol streams. The P-to-S block (414) can convert the output of the N IFFT block (413) (e.g., parallel signals) into a serial signal to generate a serial signal.

[0079] The CP addition block (415) can insert CP into the signal. The UC (416) can up-convert the frequency of the output of the CP addition block (415) to an RF (radio frequency) frequency. Additionally, the output of the CP addition block (415) can be filtered in the baseband before up-conversion.

[0080] A signal transmitted from the transmission path (410) can be input to the reception path (420). The operation in the reception path (420) may be the inverse operation of the operation in the transmission path (410). The DC (421) may down-convert the frequency of the received signal to a baseband frequency. The CP removal block (422) may remove CP from the signal. The output of the CP removal block (422) may be a serial signal. The S-to-P block (423) may convert the serial signal into parallel signals. The N FFT block (424) may generate N parallel signals by performing an FFT algorithm. The P-to-S block (425) may convert the parallel signals into a sequence of modulation symbols. The channel decoding and demodulation block (426) may perform a demodulation operation on the modulation symbols and perform a decoding operation on the result of the demodulation operation to restore the data.

[0081] In FIGS. 4a and 4b, Discrete Fourier Transform (DFT) and Inverse DFT (IDFT) may be used instead of FFT and IFFT. In FIGS. 4a and 4b, each of the blocks (e.g., components) may be implemented by at least one of hardware, software, or firmware. For example, in FIGS. 4a and 4b, some blocks may be implemented by software, and the remaining blocks may be implemented by hardware or a "combination of hardware and software." In FIGS. 4a and 4b, one block may be subdivided into multiple blocks, multiple blocks may be integrated into one block, some blocks may be omitted, and blocks supporting other functions may be added.

[0082] FIG. 5 is a conceptual diagram illustrating a first embodiment of a system frame in a communication system.

[0083] Referring to FIG. 5, time resources in a communication system can be divided into frames. For example, system frames can be set consecutively in the time domain of the communication system. The length of a system frame can be 10 ms (millisecond). The system frame number (SFN) can be set from #0 to #1023. In this case, 1024 system frames can be repeated in the time domain of the communication system. For example, the SFN of a system frame after system frame #1023 can be #0.

[0084] A single system frame may contain two half frames. The length of a single half frame may be 5ms. A half frame located at the beginning of the system frame may be referred to as "Half Frame #0", and a half frame located at the end of the system frame may be referred to as "Half Frame #1". A system frame may contain 10 subframes. The length of a single subframe may be 1ms. Within a single system frame, the 10 subframes may be referred to as "Subframe #0-9".

[0085] FIG. 6 is a conceptual diagram illustrating a first embodiment of a subframe in a communication system.

[0086] Referring to FIG. 6, one subframe may include n slots, where n is a natural number. Thus, one subframe may consist of one or more slots.

[0087] FIG. 7 is a conceptual diagram illustrating a first embodiment of a slot in a communication system.

[0088] Referring to FIG. 7, a slot may contain one or more symbols. A slot illustrated in FIG. 7 may contain 14 symbols. The length of the slot may vary depending on the number of symbols included in the slot and the length of the symbols. Alternatively, the length of the slot may vary depending on the numerology.

[0089] Numerals applied to physical signals and channels in a communication system may be variable. Numerals may be variable to meet various technical requirements of the communication system. In a communication system where CP (cyclic prefix) based OFDM waveform technology is applied, numerals may include subcarrier spacing and CP length (or CP type). Table 1 may be a first embodiment of a method for configuring numerals for a CP-OFDM based communication system. Depending on the frequency band in which the communication system operates, at least some of the numerals in Table 1 may be supported. Additionally, numerals not listed in Table 1 may be further supported in the communication system.

[0090] Subcarrier Spacing 15kHz 30kHz 60kHz 120kHz 240kHz 480kHz OFDM Symbol Length (μs) 66.733.316.78.34.22.1 CP Length (μs) 4.762.381.190.600.300.151 ms Number of OFDM Symbols within 142856112224448

[0091]

[0092] When the subcarrier spacing is 15 kHz (e.g., μ=0), the slot length may be 1 ms. In this case, one system frame may contain 10 slots. When the subcarrier spacing is 30 kHz (e.g., μ=1), the slot length may be 0.5 ms. In this case, one system frame may contain 20 slots.

[0093] When the subcarrier spacing is 60 kHz (e.g., μ=2), the slot length may be 0.25 ms. In this case, one system frame may contain 40 slots. When the subcarrier spacing is 120 kHz (e.g., μ=3), the slot length may be 0.125 ms. In this case, one system frame may contain 80 slots. When the subcarrier spacing is 240 kHz (e.g., μ=4), the slot length may be 0.0625 ms. In this case, one system frame may contain 160 slots.

[0094] A symbol can be set as a downlink (DL) symbol, a flexible (FL) symbol, or an uplink (UL) symbol. A slot consisting only of a DL symbol may be referred to as a "DL slot," a slot consisting only of an FL symbol may be referred to as a "FL slot," and a slot consisting only of a UL symbol may be referred to as a "UL slot."

[0095] The slot format can be semi-fixed by upper-layer signaling (e.g., RRC signaling). Information indicating the semi-fixed slot format may be included in system information, and the semi-fixed slot format can be set cell-specifically. Additionally, the semi-fixed slot format can be additionally set per terminal through terminal-specific upper-layer signaling (e.g., RRC signaling). The flexible symbols of the cell-specific slot format can be overridden as downlink symbols or uplink symbols by the terminal-specific upper-layer signaling. Furthermore, the slot format can be dynamically indicated by physical layer signaling (e.g., the SFI (slot format indicator) included in the DCI). The semi-fixed slot format can be overridden by the dynamically indicated slot format. For example, the semi-fixed flexible symbols can be overridden as downlink symbols or uplink symbols by the SFI.

[0096] The reference signal may be a CSI-RS (channel state information-reference signal), SRS (sounding reference signal), DM-RS (demodulation-reference signal), PT-RS (phase tracking-reference signal), etc. The channel may be a PBCH (physical broadcast channel), PDCCH (physical downlink control channel), PDSCH (physical downlink shared channel), PUCCH (physical uplink control channel), PUSCH (physical uplink shared channel), PSCCH (physical sidelink control channel), PSSCH (physical sidelink shared channel), etc. In the present disclosure, the control channel may mean PDCCH, PUCCH, or PSCCH, and the data channel may mean PDSCH, PUSCH, or PSSCH.

[0097] FIG. 8 is a conceptual diagram illustrating a first embodiment of a time-frequency resource in a communication system.

[0098] Referring to FIG. 8, a resource consisting of one symbol (e.g., an OFDM symbol) in the time domain and one subcarrier in the frequency domain can be defined as a "RE (resource element)." A resource consisting of one OFDM symbol in the time domain and K subcarriers in the frequency domain can be defined as a "REG (resource element group)." A REG can include K REs. A REG can be used as the basic unit of resource allocation in the frequency domain. K can be a natural number. For example, K can be 12. N can be a natural number. In the slot illustrated in FIG. 7, N can be 14. N OFDM symbols can be used as the basic unit of resource allocation in the time domain.

[0099] In the present disclosure, RB may mean a common RB (CRB). Alternatively, RB may mean a PRB or a virtual RB (VRB). In a communication system, a CRB may mean an RB that constitutes a set of consecutive RBs (e.g., a common RB grid) based on a reference frequency (e.g., point A). A carrier and / or bandwidth portion may be placed on the common RB grid. That is, the carrier and / or bandwidth portion may be composed of CRB(s). An RB or CRB constituting the bandwidth portion may be referred to as a PRB, and within the bandwidth portion, a CRB index may be appropriately converted to a PRB index.

[0100] Downlink data may be transmitted via PDSCH. A base station may transmit configuration information of the PDSCH (e.g., scheduling information) to a terminal via PDCCH. A terminal may obtain the configuration information of the PDSCH by receiving the PDCCH (e.g., downlink control information (DCI)). For example, the configuration information of the PDSCH may include a modulation coding scheme (MCS) used for transmitting and receiving the PDSCH, time resource information of the PDSCH, frequency resource information of the PDSCH, feedback resource information for the PDSCH, etc. PDSCH may refer to a radio resource where downlink data is transmitted and received. Alternatively, PDSCH may refer to the downlink data itself. PDCCH may refer to a radio resource where downlink control information (e.g., DCI) is transmitted and received. Alternatively, PDCCH may refer to the downlink control information itself.

[0101] The terminal may perform a monitoring operation for the PDCCH to receive the PDSCH transmitted from the base station. The base station may notify the terminal of configuration information for the monitoring operation of the PDCCH using a higher-layer message (e.g., a radio resource control (RRC) message). The configuration information for the monitoring operation of the PDCCH may include CORESET (control resource set) information and search space information.

[0102] CORESET information may include PDCCH DMRS (demodulation reference signal) information, PDCCH precoding information, PDCCH occasion information, etc. The PDCCH DMRS may be a DMRS used to demodulate the PDCCH. A PDCCH occasion may be an area where the PDCCH can exist. That is, a PDCCH occasion may be an area where DCI can be transmitted. A PDCCH occasion may be referred to as a PDCCH candidate. PDCCH occasion information may include time resource information and frequency resource information of the PDCCH occasion. In the time domain, the length of the PDCCH occasion may be indicated in symbol units. In the frequency domain, the size of the PDCCH occasion may be indicated in RB units (e.g., PRB (physical resource block) units or CRB (common resource block) units).

[0103] The search space information may include a CORESET ID (identifier) ​​associated with the search space, the period of PDCCH monitoring, and / or an offset. The period and offset of PDCCH monitoring may each be specified in slot units. Additionally, the search space information may further include the index of the symbol where the PDCCH monitoring operation begins.

[0104] A base station may configure a Bandwidth Part (BWP) for downlink communication. BWPs may be configured differently for each terminal. The base station may notify the terminal of the BWP configuration information using upper-layer signaling. Upper-layer signaling may refer to "transmission operations of system information" and / or "transmission operations of Radio Resource Control (RRC) messages." One or more BWPs may be configured for a single terminal. The terminal may receive BWP configuration information from the base station and identify the BWP(s) configured by the base station based on the BWP configuration information. If multiple BWPs are configured for downlink communication, the base station may activate one or more of the multiple BWPs. The base station may transmit the configuration information of the activated BWP(s) to the terminal using at least one of upper-layer signaling, a Medium Access Control (MAC) Control Element (CE), or a DCI. The base station may perform downlink communication using the activated BWP(s). The terminal can identify the activated BWP(s) by receiving configuration information of the activated BWP(s) from the base station, and can perform a downlink reception operation on the activated BWP(s).

[0105]

[0106] TDD (time division duplex) systems are widely used in NR deployment. In a TDD system, downlink (DL) symbols and uplink (UL) symbols can exist within a single carrier using different time resources. By considering various usage scenarios that account for coverage and latency, resources can be used more efficiently than in FDD (frequency division duplex) systems, which implies that resource scheduling at the base station becomes more important in a TDD system.

[0107] As part of the enhancement of these TDD systems, standardization is underway for subband full duplex (SBFD) technology, which allows base stations to simultaneously perform DL signal transmission and UL signal reception using non-overlapping resources in the frequency domain within the TDD band. In 3GPP Rel-18, SBFD technology was designated as a study item (SI) for discussion, and in 3GPP Rel-19, SBFD technology was designated as a work item (WI) to proceed with full-scale standardization.

[0108] In SBFD technology, it is assumed that the base station can perform DL transmission and UL reception within a single symbol (i.e., full-duplexing), and that the terminal can perform only one of the operations of DL reception or UL transmission within a single symbol (i.e., half-duplexing).

[0109] In the present disclosure, 'SBFD symbol' refers to a symbol containing subbands in which a base station can perform SBFD operations. Meanwhile, 'non-SFBD symbol' may refer to a symbol that is not an SBFD symbol. Generally, a subband for SBFD may be interpreted as referring to a UL subband. As a result of standardization discussions, it was agreed that UL subbands may also exist in symbols in which SSB is transmitted.

[0110] Meanwhile, 3GPP Rel-19 agreed that SBFD operation is performed based on the semi-static configuration of time and frequency domain resources. Although allowing dynamic configuration could be more efficient in terms of resource management, it was decided that standardization for semi-static configuration would proceed first, as it could lead to many problems due to the need to consider conflicts with resources allocated by the semi-static configuration. Additionally, it was decided that subbands exist only within DL and / or flexible symbols configured by the TDD-UL-DL configuration common. Furthermore, within the time domain, transitions between non-SBFD and SBFD symbols and transitions from SBFD to non-SBFD symbols are limited to one per slot. This is because frequent transitions increase implementation complexity and can cause interference between transmitted and received signals during the transition. Regarding the setting of time / frequency resources for subbands, it was agreed that the basic basis is to ensure that the terminal is aware of information about the time / frequency resources of the subband in advance.

[0111] As previously mentioned, it has been agreed that DL and / or flexible symbols configured via TDD-UL-DL-ConfigCommon can be configured as SBFD symbols. TDD-UL-DL-ConfigCommon is configuration information for setting patterns for time-domain DL or UL resources in a TDD system, and such patterns may change depending on the network environment. The current standard stipulates that a maximum of two patterns can be configured. TDD-UL-DL-ConfigCommon is a cell-specific parameter, and the base station can change the configuration of symbols in specific slots within the pre-configured patterns on a terminal-by-terminal basis; however, the slots for which configuration changes are possible are limited to the slots flexibly configured by TDD-UL-DL-ConfigCommon. The RRC signaling used in this case is TDD-UL-DL-ConfigDedicated.

[0112] Table 2 shows the specific configuration of TDD-UL-DL-ConfigCommon.

[0113]

[0114]

[0115] In Table 2, dl-UL-TransmissionPeriodicity indicates the period of the DL-UL pattern, and nrofDownlinkSlots indicates the total number of DL slots that exist consecutively at the beginning of each DL-UL pattern, with a maximum value of 320. nrofDownlinkSymbols indicates the number of DL symbols that exist consecutively at the beginning of the slots following the last total DL slot, derived from nrofDownlinkSlots, and if this value is set to 0, it may indicate that there are no partial-downlink slots. nrofUplinkSlots indicates the total number of UL slots that exist consecutively at the end of each DL-UL pattern, and in this release, the maximum value of this field is 320. nrofUplinkSymbols represents the number of consecutive UL symbols at the end of the slots preceding the first full UL slot, derived from nrofUplinkSlots, and if the value is set to 0, it may indicate that there are no partial-uplink slots.

[0116] Table 3 shows the specific configuration of TDD-UL-DL-ConfigDedicated.

[0117]

[0118]

[0119] Referring to Table 3, slotSpecificConfigurationsToAddModList included in TDD-UL-DL-ConfigDedicated allows overriding the UL / DL assignments provided by tdd-UL-DL-configurationCommon. nrofDownlinkSymbols included in TDD-UL-DL-SlotConfig indicates the number of consecutive DL symbols at the beginning of the slot identified by slotIndex; if this field is absent, the terminal assumes there are no preceding DL symbols. nrofUplinkSymbols indicates the number of consecutive UL symbols at the end of the slot identified by slotIndex; if this field is absent, the terminal assumes there are no trailing UL symbols. slotIndex identifies the slot within the given slot configuration cycle in tdd-UL-DL-configurationCommon. Symbols indicates the direction (downlink or uplink) of the symbols within the slot; if set to allDownlink, it indicates that all symbols within the slot are used for downlinks; if set to allUplink, it indicates that all symbols within the slot are used for uplinks; and if set to explicit, it explicitly indicates how many symbols are assigned to downlinks and uplinks at the beginning and end of the slot, respectively.

[0120] Referring to Tables 2 and 3, it can be seen that the DL / UL pattern by TDD-UL-DL-ConfigCommon is repeated for a specific interval length (e.g., periodicity), with the first half of the interval used for DL ​​and the second half for UL. Furthermore, the available values ​​for this periodicity may vary depending on the reference numerology. Current standards stipulate that a guard time or gap required for switching is necessary between consecutive DL symbols / slots and UL symbols / slots, but that no separate guard time or gap is required between consecutive UL symbols / slots and DL symbols / slots. This is because the presence of propagation delay in DL signals causes interference with UL symbols. Additionally, unlike DL, UL does not encounter problems in receiving consecutive DL signals because the base station transmits a Timing Advance command to the terminal.

[0121] Hereinafter, for the sake of technical convenience, TDD-UL-DL-ConfigCommon and TDD-UL-DL-ConfigDedicated signalings are abbreviated as 'TDD common' and 'TDD dedicated', respectively, and the subband for SBFD is abbreviated as 'UL subband'. Additionally, since the DL symbols / slots, UL symbols / slots, and flexible symbols / slots configured by TDD common and TDD dedicated can be arranged sequentially along the time axis, they are referred to as 'DL region', 'UL region', and 'flexible region', respectively. Furthermore, terminals that support or recognize SBFD are referred to as 'SBFD UE', and terminals that do not support or recognize SBFD are referred to as 'Non-SBFD UE'. Also, the term 'legacy configuration' refers to the configuration for Non-SBFD UEs. In addition, RACH occasions (RO) that non-SBFD UEs do not recognize are referred to as 'SBFD RO', and ROs that non-SBFD UEs can recognize are referred to as 'legacy RO'.

[0122]

[0123] For the configuration of PRACH transmission in an SBFD system, options may be supported: Option #1, which follows the existing configuration of PRACH transmission in a non-SBFD system exactly, and Option #2, which includes separate additional settings in addition to the existing configuration of PRACH transmission in a non-SBFD system and utilizes both configurations. For technical convenience, legacy RACH configuration refers to the configuration for PRACH transmission in a non-SBFD system, and additional RACH configuration refers to additional configuration to support an SBFD system. In the following, unless otherwise specified, Option #1 refers to a method of configuring PRACH-related resources for an SBFD UE using only legacy RACH configuration, and Option #2 refers to a method of configuring PRACH-related resources using separate additional settings for an SBFD UE.

[0124] Regarding the mapping relationship between ROs for transmitting a PRACH corresponding to an SSB (synchronization signal block), for Option #2, it was agreed that ROs are valid if they are located within at least fully usable UL PRBs (physical resource blocks) and do not overlap with the SSB. Additionally, although ROs containing symbols of fundamentally different symbol types (i.e., 'SBFD symbols' and 'non-SBFD symbols') are generally deemed invalid, under Option #2, they may be configured as valid ROs based on network judgment. For the relevant RO (i.e., the RO containing symbols of different symbol types), the terminal assumes the following.

[0125] The same frequency resources are used in both the SBFD segment and the non-SBFD segment of -PRACH.

[0126] The same UL transmission power is used in both the SBFD and non-SBFD sections of -PRACH.

[0127] The same UL spatial domain filter is used for both the SBFD and non-SBFD sections of -PRACH.

[0128] - The terminal does not interrupt PRACH transmission during the transition interval / gap (if any) between SBFD symbols and non-SBFD symbols.

[0129] There are no phase coherency requirements for terminals between the SBFD and non-SBFD segments of PRACH.

[0130]

[0131] In this disclosure, additional ROs generated according to Option #1 or Option #2 are defined as 'additional ROs'. For example, additional ROs in Option #1 refer to ROs existing within SBFD symbols, and additional ROs in Option #2 refer to all ROs generated based on additional settings.

[0132] In current standards, while it has been agreed that existing rules should be applied as they are for SSB to RO mapping rules, issues requiring discussion and resolution may arise. This disclosure describes issues requiring discussion regarding the mapping relationship between SSB and RO and presents solutions. In particular, a method for determining which RO type (i.e., legacy RO or additional RO) to send a preamble to the terminal side when a CFRA (contention-free randm access) procedure is triggered based on the PDCCH order is also described.

[0133]

[0134] CFRA triggered by the PDCCH order

[0135] While general RACH procedure operations are initiated by the transmission of a preamble at the terminal side, PDCCH order-based RACH procedures can be initiated based on the judgment of the base station side. Considering the triggering of PDCCH order-based CFRA procedures in the SBFD system, as described above, the SBFD UE can transmit preambles not only to legacy ROs but also to additional ROs; furthermore, to ensure equity with legacy terminals, it has been agreed that the SBFD UE performs power control for preamble retransmission based on the symbol type of the RO. Additionally, discussions are underway regarding which type of RO the RACH procedure should be executed by the SBFD UE. Since a method for providing information indicating the RO type where the preamble is transmitted is being discussed when triggering a PDCCH order-based RACH procedure, a definition of such indication method is required. The present disclosure proposes, as examples of the relevant indication methods, a method of reinterpreting the field(s) of an existing DCI, a method of partitioning the preambles, or a method of using a separate RNTI.

[0136]

[0137] Method 1-1: Use existing DCI fields as replacements

[0138] Conventional PDCCH order-based RACH procedure triggering is indicated when the CRC of the PDCCH is scrambled by the terminal's C-RNTI and all bits of the 'frequency-domain resource assignment' field are set to 1.

[0139] In one embodiment, bits of the corresponding field (frequency domain resource assignment field) may be utilized to indicate the RO type for the SBFD UE. For example, two LSB (least significant bits) bits or two MSB (most significant bits) bits of the corresponding field may be utilized to indicate the association between the indicated PDCCH order and a specific RO type, and to indicate whether there is a request for RACH transmission using the corresponding RO. Specifically, among two consecutive bits, the first bit may be associated with preamble transmission using legacy RO, and the second bit may be associated with preamble transmission using additional RO. Assuming that the corresponding field (i.e., frequency domain resource assignment field) consists of a total of 7 bits and two LSB bits are used for RO type setting, 'xxxxx00', 'xxxxx01', 'xxxxx10', and 'xxxxx11' may be mapped to 'terminal implementation', 'legacy RO', 'additional RO', and 'both', respectively.

[0140] 'Terminal implementation' may mean allowing the terminal to select one of two RO types and transmit a preamble based on its own decision without any conditions, and 'both' may mean that transmission of a preamble is possible for all RO types. In this case, the selection condition for the RO type may be additionally transmitted to the terminal from the base station via RRC signaling or system information. Alternatively, some of the code points that can be represented by 2 bits may be left in a reserved state. For example, '10' may be used as 'Legacy RO' and '11' as 'Additional RO', and the remaining code points '00' and '11' may be left in a reserved state.

[0141] Additionally, all parameters related to RO settings indicated by the PDCCH order can be utilized for selecting an RO according to the corresponding RO type. That is, the terminal can utilize information indicated for RO selection, such as the preamble index, SSB index, and mask index, for selecting an RO according to the indicated RO type. In the above embodiment, the case using 2 bits was given as an example, but it can be extended to N bits. N MSB or LSB bits can be used to indicate the RO type, and the remaining bits can all be set to '1'.

[0142] In another embodiment, reserved code points of an RO mask index (e.g., PRACH mask index, msgA-SSB-SharedRO-MaskIndex, or ssb-SharedRO-MaskIndex) may be used. The mask index field may be used together with the SSB index to indicate a specific RO. That is, the SSB index included in the PDCCH order is intended to ensure beam synchronization by specifying which beam direction the terminal should transmit the RACH preamble based on, and the mask index is intended to reduce collisions and improve resource control by limiting the ROs available to the terminal. Thus, the PDCCH order can instruct the terminal to transmit the RACH preamble using specific ROs in the specified beam direction (SSB index).

[0143] The mask index can consist of 4 bits. Of the 16 code points represented by the 4 bits, 11 code points are currently in use, and 5 code points remain in a reserved state. Therefore, one or more of the reserved code points may be used to indicate RO types. For example, if one code point is used, that code point may indicate all additional ROs. If two code points are used, one code point may indicate even-numbered additional ROs, and the other code point may indicate odd-numbered additional ROs. In other words, the code points currently in use (e.g., 0 to 10) are used to indicate legacy ROs, while the reserved code points (e.g., 11 to 15) may all be used to indicate specific additional ROs. Table 4 shows an example.

[0144]

[0145]

[0146] In another embodiment, the RO mask index field is configured with 5 bits to represent a total of 32 code points. In this case, instruction information for additional ROs can be represented using code points 11 to 21 by borrowing the instruction information expressed using existing code points 0 to 10. Tables 5 and 6 show examples thereof.

[0147]

[0148]

[0149]

[0150]

[0151] Method 1-2: Utilizing reserved bits

[0152] The reserved bits of the DCI that trigger the PDDCH order can be utilized. By utilizing N bits among the reserved bits, the base station can instruct the terminal to transmit a preamble using a specific RO type. For example, if 1 bit is used to indicate the RO type, bit values ​​'1' and '0' are associated with different RO types, respectively, and the terminal can transmit a preamble in the RO type indicated by that bit. Alternatively, 2 bits may be utilized as in Method 1-1 above. Additionally, all parameters related to RO configuration indicated by the PDCCH order can be utilized for RO selection according to the corresponding RO type. That is, the terminal can utilize information indicated for RO selection, such as the preamble index, SSB index, and mask index, for RO selection according to the indicated RO type.

[0153]

[0154] Method 1-3: Preamble partitioning

[0155] When additional ROs are configured, the base station may allocate a portion of the total preambles intended for the legacy ROs to the additional ROs. That is, it may separate a subgroup of preambles expected to be transmitted from the legacy ROs from a subgroup of preambles expected to be transmitted from the additional ROs. The base station may establish a preamble index within the DCI that triggers a PDCCH order based on the preamble indices belonging to each of the separated subgroups. The terminal may identify the RO type based on the preamble index within the DCI and transmit a preamble from the RO corresponding to the identified RO type.

[0156] Even if an agreement is reached to mix all preambles regardless of RO type due to concerns about the depletion of preamble numbers, the base station may transmit information regarding separate preamble partitioning to the terminal for the PDCCH order-based RACH procedure, and such information may be included in the RACH configuration information. Information regarding preamble partitioning is not utilized in the RACH procedure initiated by the terminal, but can be utilized only when the base station initiates the RACH procedure via the PDDCH order. Information regarding preamble partitioning may be transmitted to the terminal via RRC signaling or system information.

[0157] FIG. 9 is a conceptual diagram illustrating a preamble division according to an embodiment of the present disclosure.

[0158] When the base station triggers a RACH procedure based on a PDCCH order, it may transmit preamble splitting information, which groups preambles by RO type or symbol type including RO, to the terminal before the transmission of the PDCCH order, and the terminal may expect the transmission of a preamble from an RO belonging to a specific RO type or a specific symbol type according to the subgroup to which the preamble indicated by the PDCCH order belongs.

[0159] Referring to FIG. 9, the configuration of contention-based (CB) preambles is exemplified assuming that Msg1-FDM is set to 1 and SSB-perRACH-occasion is set to 'one'. Case (a) illustrates the case where all configured preambles are used regardless of RO type, and case (b) illustrates the case where preambles are divided into subgroups by RO type. The terminal can determine the RO type of the RO to which the terminal must transmit the preamble based on the subgroup to which a specific preamble index indicated by the PDCCH order belongs.

[0160] Meanwhile, preamble splitting can be applied not only to PDCCH order-based RACH procedures but also to general RACH procedures initiated by the terminal, and the corresponding signaling can be transmitted through system information.

[0161] FIG. 10 is a conceptual diagram illustrating various cases of preamble division according to an embodiment of the present disclosure.

[0162] Referring to FIG. 10, case (a) shows an example of a conventional preamble configuration when only legacy ROs are considered without additional ROs, and the total number of preambles assigned to CBRA and CFRA procedures is the total number of preambles minus the number of preambles used for other purposes (e.g., system information request (SI request)).

[0163] In case (b), when the base station sets up an additional RO, the preambles assigned to the previously described CBRA and CFRA procedures may be divided for the CBRA and CFRA procedures using the legacy RO and the CBRA and CFRA procedures using the additional RO, respectively.

[0164] Case (c) corresponds to the case where preambles for CBRA procedures are set regardless of RO type, and preambles for CFRA procedures are set for each RO type.

[0165]

[0166] Method 1-4: Introduction of a New RNTI

[0167] According to the existing method, the CRC of the DCI for a PDCCH order-based RACH procedure is scrambled with the terminal's C-RNTI. A method may be considered to scramble the CRC of the DCI triggering the PDCCH order by defining a new RNTI instead of the C_RNTI. The terminal can recognize the triggering of a RACH procedure associated with a specific RO type based on the RNTI scrambled with the received DCI.

[0168] That is, if the C-RNTI is scrambled in the received DCI, the terminal can expect the transmission of a preamble from a legacy RO and can use all information constituting the fields of the DCI for RO selection within the legacy ROs. Meanwhile, if the new RNTI is scrambled in the received DCI, the terminal can expect the transmission of a preamble from an additional RO and can use all information constituting the fields of the DCI for RO selection within the additional ROs. This is because the same RO indices and preamble indices are used in both the additional ROs and the legacy ROs. When applying Method 1-4, the field configuration of the DCI scrambled with the new RNTI can be maintained identically to the field configuration of the legacy PDCCH order.

[0169]

[0170] FIG. 11 is a flowchart for explaining embodiments of the present invention.

[0171] Referring to FIG. 11, the terminal can receive downlink control information (DCI) including a PDCCH order from a base station (S1110). At this time, the terminal may be an SBFD UE that supports or recognizes the previously described SBFD.

[0172] Next, the terminal can determine the type of RO to transmit the RACH preamble based on the information included in the DCI (S1120). That is, the terminal can determine the type of RO to transmit the RACH preamble as a legacy RO or an additional RO based on the information included in the DCI.

[0173] Here, the RO type may be indicated by a field included in the DCI (i.e., Method 1-1), by reserved bit(s) included in the DCI (i.e., Method 1-2), or by a radio network temporary identifier (RNTI) scrambled into the CRC of the DCI (i.e., Method 1-3).

[0174] For example, a field included in the DCI that indicates the RO type may be a frequency-domain resource assignment field or an RO mask index field. However, one or more combinations of the various fields included in the DCI may be used to indicate the RO type.

[0175] Meanwhile, if the terminal receives information about subgroups of partitioned preambles before receiving the DCI (S1101), the RO type may be determined as the RO type corresponding to the subgroup to which the preamble index indicated in the DCI belongs.

[0176] For example, if the subgroup to which the preamble index indicated by the DCI belongs is a subgroup corresponding to a legacy RO, the terminal may determine the RO type for preamble transmission as a legacy RO. Conversely, if the subgroup to which the preamble index indicated by the DCI belongs is a subgroup corresponding to an additional RO, the terminal may determine the RO type for preamble transmission as an additional RO.

[0177] The above subgroups may include a subgroup of preambles for a CBRA (contention-based random access) procedure for legacy ROs, a subgroup of preambles for a CFRA (contention-free random access) procedure for legacy ROs, a subgroup of preambles for a CBRA procedure for additional ROs, and a subgroup of preambles for a CFRA procedure for additional ROs (i.e., case (b) of FIG. 10).

[0178] Alternatively, the above subgroups may include a subgroup of preambles for CBRA procedures for legacy ROs and additional ROs, a subgroup of preambles for CFRA procedures for legacy ROs, and a subgroup of preambles for CBRA procedures for additional ROs (i.e., case (c) of FIG. 10).

[0179] Finally, the terminal can transmit a preamble from the RO according to the RO type determined in step (S1120) to the base station (S1130).

[0180]

[0181] Selection of Legacy RO and Additional RO in SBFD UE

[0182] In the case of Option #2, the SBFD UE can receive both the configuration for legacy ROs and the configuration for additional ROs. Power control can be applied separately for each RO type, and the terminal can transmit a preamble from all types of ROs or transmit a preamble from a single type of RO.

[0183] If the SBFD UE operates to perform RACH on the nearest RO based on the RO type of the RO at the time it decides to perform the RACH procedure, the base station may not set additional information to support the terminal's RO selection. However, if the terminal is required to transmit a preamble on a specific RO type appropriate for a specific situation, the base station may need to additionally set information necessary to transmit a preamble on that RO type for the terminal.

[0184]

[0185] Method 2-1: Providing additional conditions to determine the RO type

[0186] If the base station provides information on additional conditions required to determine the RO type at the terminal, such information on additional conditions may include an RSRP threshold for selecting an additional RO, and such RSRP threshold may be a value greater than the RSRP threshold of the legacy RO. This is because the bandwidth of the UL subband is smaller than the bandwidth of the UL band, so the number of valid ROs within the UL subband may be small and the probability of collision may be high. If an RSRP threshold for selecting an additional RO is provided, the terminal can expect a preamble transmission from the legacy RO if the RSRP value of the received SSB does not satisfy the RSRP threshold.

[0187]

[0188] Method 2-2: Selecting RO Type Based on Terminal Status

[0189] In another embodiment, the base station may instruct the SBFD UE to transmit to a specific RO type through explicit signaling (e.g., system information or RRC signaling). In this case, the terminal may be required to select an RO type and transmit a preamble based on its current state. For example, if the base station instructs the SBFD UE to transmit a preamble through a specific RO type via system information, a terminal in an RRC idle / inactive state may only transmit a preamble to the instructed RO type. On the other hand, for an RRC connected terminal that needs to perform a RACH procedure from a beam management perspective, if a beam failure is declared and a beam failure recovery (BFR) request must be transmitted, the preamble may be transmitted to the nearest RO (additional RO or legacy RO) regardless of the RO type. Alternatively, the base station may transmit a time condition to the terminal, the time may be set in units of symbols or slots, and if an SSB or DL ​​symbol exists within the time, the terminal may be configured not to transmit a preamble in an additional RO.

[0190]

[0191] Mapping between SSB and RO when additional ROs and legacy ROs overlap

[0192] As previously explained, in the case of Option #2, the base station transmits the configuration for the legacy RO and the configuration for the additional RO to the SBFD UE. In this case, ROs may overlap depending on the configuration of the legacy RO and the additional RO. To handle such cases, additional rules regarding the handling of overlapping ROs and mapping with the SSB are required.

[0193] The easiest way to solve the above problem is to expect the SBFD UE to be configured by the base station so that there is no overlap between additional ROs and legacy ROs. If this is not possible, the terminal can perform mapping with the SSB for the valid ROs using one or more of the following methods.

[0194] Method 3-1: An SBFD UE may not transmit a preamble in additional ROs configured within non-SBFD symbols. Therefore, it may drop the transmission of a preamble in additional ROs that (partially) overlap with legacy ROs.

[0195] Method 3-2: An SBFD UE may not send a preamble on legacy ROs configured within non-SBFD symbols. Therefore, the preamble may be dropped on legacy ROs that overlap with additional ROs (partially).

[0196] Method 3-3: An SBFD UE may not send a preamble on legacy ROs configured within an SBFD symbol. Therefore, it may drop the preamble transmission on legacy ROs that overlap with additional ROs (partially).

[0197] Method 3-4: An SBFD UE may not transmit a preamble in additional ROs configured within an SBFD symbol. Therefore, it may drop the transmission of a preamble in additional ROs that (partially) overlap with legacy ROs.

[0198] Method 3-5: An SBFD UE can expect preamble transmission for both legacy ROs and additional ROs within the SBFD symbol. In such cases, if the legacy RO and additional ROs partially overlap, the standard may specify which of the two RO types is always dropped. Alternatively, the terminal may operate by prioritizing the RO type that exists earlier in the time axis and dropping the RO type that exists later in the time axis that (partially) overlaps. Or, the base station may explicitly include relevant information regarding which type of RO to drop in the RACH configuration information and transmit it to the terminal.

[0199] Method 3-6: An SBFD UE can expect preamble transmission for both legacy ROs and additional ROs within non-SBFD symbols. In such cases, if there is partial overlap between the legacy RO and the additional RO, the standard may specify which of the two RO types is always dropped. Alternatively, the terminal may operate by prioritizing the RO type that exists earlier in the time axis and dropping the RO type that exists later in the time axis that (partially) overlaps. Or, the base station may explicitly include relevant information regarding which type of RO to drop in the RACH configuration information and transmit it to the terminal.

[0200]

[0201] The terminal may be configured with additional ROs and legacy ROs, respectively, in time intervals that partially or wholly overlap, and the additional ROs and legacy ROs may exist in frequency domains that do not overlap with each other. In this case, the terminal may expect preamble transmission in one RO type, and the selection of one RO type may be performed according to Method 2-1 and / or Method 2-2 above. Alternatively, the standard may stipulate that additional ROs and legacy ROs are not configured for the terminal as in the above situation. Alternatively, in the above situation, the terminal may expect preamble transmission in all RO types.

[0202]

[0203] The methods described in this disclosure are not limited to specific scenarios and types and may be applied to other scenarios and types, and may be used in a single or multiple combination depending on the conditions.

[0204] The UL subband described in this disclosure represents a time and frequency range in which uplink transmission is possible in DL and / or flexible symbols, and may be replaced by 'UL usable PRBs', which refers to the overlapping area between the UL subband and the active UL BWP in the context of this disclosure, which targets the transmission and reception operations of an actual terminal. Likewise, the DL subband and the DL usable PRBs may also be regarded as the same in this disclosure.

[0205] With respect to the function(s) described in this disclosure, the terminal may notify the base station of whether it supports them, and the base station may transmit different information to the terminal depending on the function(s) supported by the terminal. In addition, some of the details proposed in this disclosure may be equally applicable to other methods.

[0206] The configuration of the UL subband described in this disclosure can be transmitted via RRC signaling and can basically be provided after the configuration of the TDD common.

[0207] The methods described in this disclosure can be utilized in unlicensed bands as well as licensed bands, and can be extended to uplink transmission power in sidelinks and supplementary uplinks (SULs).

[0208] With respect to the function(s) described in the present disclosure, the terminal may report to the base station whether it supports the said function when reporting capability, and the base station may perform signaling and operations related to the methods described in the present disclosure according to the terminal's capability.

[0209] The methods described in this disclosure may be applied together in a single or multiple combinations and may be applied commonly regardless of the RRC status.

[0210] The methods described in this disclosure may be applied to various subsequent types of RACH procedures, such as 4-step RACH procedures as well as 2-step RACH procedures, and the names of messages or information defined in this disclosure may be varied.

[0211]

[0212] The operation of the method according to the present disclosure can be implemented as a computer-readable program or code on a computer-readable recording medium. A computer-readable recording medium includes any type of recording device in which information that can be read by a computer system is stored. Additionally, a computer-readable recording medium may be distributed across networked computer systems, allowing the computer-readable program or code to be stored and executed in a distributed manner.

[0213] In addition, computer-readable recording media may include hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, and flash memory. Program instructions may include machine code, such as that generated by a compiler, as well as high-level language code that can be executed by a computer using an interpreter, etc.

[0214] Some aspects of the present disclosure have been described in the context of a device, but may also be described according to a corresponding method, wherein a block or device corresponds to a method step or a feature of a method step. Similarly, aspects described in the context of a method may also be described according to a corresponding block or item or a feature of a corresponding device. Some or all of the method steps may be performed by (or using) a hardware device, such as, for example, a microprocessor, a programmable computer, or an electronic circuit. In some embodiments, at least one of the most important method steps may be performed by such a device.

[0215] A programmable logic device (e.g., a field-programmable gate array) may be used to perform some or all of the functions of the methods described in this disclosure. A field-programmable gate array may operate with a microprocessor to perform one of the methods described in this disclosure. Generally, it is preferable that the methods be performed by some hardware device.

[0216] Although the present disclosure has been described with reference to preferred embodiments, those skilled in the art will understand that various modifications and changes can be made to the present disclosure without departing from the spirit and scope of the present disclosure as set forth in the following claims.

Claims

1. In the method of the terminal, A step of receiving downlink control information (DCI) including a PDCCH order from a base station; A step of determining a RACH (random access channel) occupancy (RO) type based on information included in the above DCI; and A step comprising transmitting a preamble from an RO according to the determined RO type to the base station, method.

2. In Claim 1, The above RO type is a legacy RO or an additional RO, method.

3. In Claim 1, The above RO type is indicated by a field included in the DCI, by reserved bit(s) included in the DCI, or by a radio network temporary identifier (RNTI) scrambled into the CRC of the DCI, method.

4. In Claim 3, The field included in the above DCI is a frequency-domain resource assignment field or an RO mask index field, method.

5. In Claim 1, The step of receiving information on subgroups of partitioned preambles prior to the step of receiving the DCI is further included, wherein the RO type is determined as the RO type corresponding to the subgroup to which the preamble index indicated in the DCI belongs. method.

6. In Claim 5, The above subgroups include a subgroup of preambles for contention-based random access (CBRA) procedures for legacy ROs, a subgroup of preambles for contention-free random access (CFRA) procedures for legacy ROs, a subgroup of preambles for CBRA procedures for additional ROs, and a subgroup of preambles for CFRA procedures for additional ROs. method.

7. In Claim 5, The above subgroups include a subgroup of preambles for CBRA procedures for legacy ROs and additional ROs, a subgroup of preambles for CFRA procedures for legacy ROs, and a subgroup of preambles for CBRA procedures for additional ROs. method.

8. Regarding the base station method, A step of transmitting downlink control information (DCI) including a PDCCH order to a terminal; and The method includes the step of receiving a preamble from the terminal, The above preamble is received at an RO according to a RACH (random access channel) occupancy (RO) type determined based on information included in the above DCI, method.

9. In Claim 8, The above RO type is a legacy RO or an additional RO, method.

10. In Claim 8, The above RO type is indicated by a field included in the DCI, by reserved bit(s) included in the DCI, or by a radio network temporary identifier (RNTI) scrambled into the CRC of the DCI, method.

11. In Claim 10, The field included in the above DCI is a frequency-domain resource assignment field or an RO mask index field, method.

12. In claim 8, The step of transmitting information about subgroups of partitioned preambles to the terminal prior to the step of transmitting the DCI is further included, wherein the RO type is determined as the RO type corresponding to the subgroup to which the preamble index indicated in the DCI belongs. method.

13. In Claim 12, The above subgroups include a subgroup of preambles for contention-based random access (CBRA) procedures for legacy ROs, a subgroup of preambles for contention-free random access (CFRA) procedures for legacy ROs, a subgroup of preambles for CBRA procedures for additional ROs, and a subgroup of preambles for CFRA procedures for additional ROs. method.

14. In Claim 12, The above subgroups include a subgroup of preambles for CBRA procedures for legacy ROs and additional ROs, a subgroup of preambles for CFRA procedures for legacy ROs, and a subgroup of preambles for CBRA procedures for additional ROs. method.

15. In a terminal comprising at least one processor, the at least one processor is: the terminal A step of receiving downlink control information (DCI) including a PDCCH order from a base station; A step of determining a RACH (random access channel) occupancy (RO) type based on information included in the above DCI; and Performing the step of transmitting a preamble from the RO according to the determined RO type to the base station, Terminal.

16. In Claim 15, The above RO type is a legacy RO or an additional RO, Terminal.

17. In Claim 15, The above RO type is indicated by a field included in the DCI, by reserved bit(s) included in the DCI, or by a radio network temporary identifier (RNTI) scrambled into the CRC of the DCI, Terminal.

18. In Claim 1, The above at least one processor enables the terminal to additionally perform the step of receiving information about subgroups of partitioned preambles prior to the step of receiving the DCI, wherein the RO type is determined as the RO type corresponding to the subgroup to which the preamble index indicated in the DCI belongs. Terminal.

19. In Claim 18, The above subgroups include a subgroup of preambles for contention-based random access (CBRA) procedures for legacy ROs, a subgroup of preambles for contention-free random access (CFRA) procedures for legacy ROs, a subgroup of preambles for CBRA procedures for additional ROs, and a subgroup of preambles for CFRA procedures for additional ROs. Terminal.

20. In Claim 18, The above subgroups include a subgroup of preambles for CBRA procedures for legacy ROs and additional ROs, a subgroup of preambles for CFRA procedures for legacy ROs, and a subgroup of preambles for CBRA procedures for additional ROs. Terminal.

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