Terminal, wireless communication method, and base station

Abstract

A terminal according to one aspect of the present disclosure is characterized by comprising: a control unit that controls the transmission timing of a physical random access channel (PRACH) without receiving a synchronization signal block (SSB); and a transmission unit that transmits the PRACH on the basis of the transmission timing. According to one aspect of the present disclosure, it is possible to suitably perform initial access.

Description

Terminal, wireless communication method and base station

[0001] The present disclosure relates to a terminal, a wireless communication method, and a base station in a next-generation mobile communication system.

[0002] Long Term Evolution (LTE) has been specified for the Universal Mobile Telecommunications System (UMTS) network with the aim of achieving higher data rates and lower latency (Non-Patent Document 1). Also, LTE-Advanced (3GPP Rel. 10-14) has been specified with the aim of achieving higher capacity and more advanced features than LTE (Third Generation Partnership Project (3GPP (registered trademark)) Release (Rel.) 8, 9).

[0003] Successor systems to LTE (e.g., 5th generation mobile communication system (5G), 5G+ (plus), 6th generation mobile communication system (6G), New Radio (NR), 3GPP Rel. 15 or later, etc.) are also being considered.

[0004] 3GPP TS 36.300 V8.12.0 “Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 (Release 8)”, April 2010

[0005] In future wireless communication systems (e.g., Beyond 5G and 6G), from the viewpoint of further improving the efficiency of communication, communication (asynchronous communication, sync-free communication) that assumes asynchronous operation between a terminal (user terminal, User Equipment (UE)) and a base station is being considered. Specifically, in the initial access procedure, it is being considered to simplify the procedures required for communication by eliminating the procedure for synchronization between a UE and a base station in existing specifications (e.g., NR). Asynchronous communication is expected to reduce overhead due to synchronization and maximize communication efficiency.

[0006] However, in the initial access procedure of asynchronous communication, it is not possible to accurately estimate / understand the time / frequency resources for transmitting / receiving signals / channels by the UE / base station, which may result in an inappropriate initial access procedure, resulting in a decrease in system performance, such as a decrease in communication throughput.

[0007] Therefore, one object of the present disclosure is to provide a terminal, a wireless communication method, and a base station that can properly perform initial access.

[0008] A terminal according to one aspect of the present disclosure is characterized by having a control unit that controls the transmission timing of a physical random access channel (PRACH) without receiving a synchronization signal block (SSB), and a transmission unit that transmits the PRACH based on the transmission timing.

[0009] According to one aspect of the present disclosure, initial access can be performed appropriately.

[0010] Fig. 1 is a diagram showing an example of 4-step RA. Fig. 2 is a diagram showing an example of 2-step RA. Fig. 3 is a diagram showing an example of PRACH transmission in a case where a UE and a base station are unsynchronized and a case where a UE and a base station are roughly synchronized. Fig. 4 is a diagram showing an example of PRACH transmission in a case where a UE and a base station are unsynchronized and a case where a UE and a base station are roughly synchronized. Fig. 5 is a diagram showing an example of transmission of HARQ-ACK for Msg. 3 and Msg. 4 in a case where a UE and a base station are roughly synchronized. Fig. 6 is a diagram showing an example of transmission of Msg. 3 in a case where a UE and a base station are roughly synchronized. Fig. 7 is a diagram showing an example of transmission of Msg. 3 in a case where a UE and a base station are roughly synchronized. FIG. 8 is a diagram showing an example of a schematic configuration of a wireless communication system according to an embodiment. FIG. 9 is a diagram showing an example of a configuration of a base station according to an embodiment. FIG. 10 is a diagram showing an example of a configuration of a user terminal according to an embodiment. FIG. 11 is a diagram showing an example of a hardware configuration of a base station and a user terminal according to an embodiment. FIG. 12 is a diagram showing an example of a vehicle according to an embodiment.

[0011] (Initial Access Procedure) In the initial access procedure of NR, the UE (RRC_IDLE mode) performs a random access procedure after receiving an SS / PBCH block (SSB) (see Figure 1).

[0012] In the random access procedure, the UE transmits Msg. 1 (PRACH / random access preamble / preamble), receives Msg. 2 (PDCCH, PDSCH including random access response (RAR)), transmits Msg. 3 (PUSCH scheduled by RAR UL grant), and receives Msg. 4 (PDCCH, PDSCH including UE contention resolution identity) (see Figure 1). After that, when the base station (network) transmits an ACK for Msg. 4 from the UE, an RRC connection is established (RRC_CONNECTED mode).

[0013] SSB reception includes PSS detection, SSS detection, PBCH-DMRS detection, and PBCH reception. PSS detection includes detecting part of the physical cell ID (PCI), detecting (synchronizing) OFDM symbol timing, and (coarse) frequency synchronization. SSS detection includes detecting the physical cell ID. PBCH-DMRS detection includes detecting (part of) the SSB index within a half radio frame (5 ms). PBCH reception includes detecting the system frame number (SFN) and radio frame timing (SSB index), receiving configuration information for receiving remaining minimum system information (RMSI, SIB1), and recognizing whether the UE can camp on that cell (carrier).

[0014] SSB has a bandwidth of 20 RBs and a time of 4 symbols. The transmission period of SSB can be set to {5, 10, 20, 40, 80, 160} ms. In a half frame, multiple symbol positions of SSB are defined based on the frequency range (FR1, FR2).

[0015] The PBCH has a payload of 56 bits. N repetitions of the PBCH are transmitted within a period of 80 ms, where N depends on the SSB transmission period.

[0016] The system information consists of the MIB, RMSI (SIB1), and other system information (OSI) carried by the PBCH. SIB1 contains information for RACH setup and RACH procedures. The time / frequency resource relationship between the SSB and the PDCCH monitoring resource for SIB1 is configured by the PBCH.

[0017] The frequency on which the UE searches for the PSS / SSS may be referred to as a synchronization raster.

[0018] In NR, the center frequency of SSB is located on the synchronous raster.

[0019] A synchronization raster is defined for each frequency range (FR1 / FR2).

[0020] The wider the frequency interval of the synchronization rasters (the fewer the number of synchronization rasters), the shorter the time required for searching during initial access, and the lighter the load.

[0021] Candidates for frequency positions where component carriers (CCs) are arranged are called a channel raster.

[0022] The interval of the synchronization rasters is determined to satisfy a specific condition, specifically, the interval of the synchronization rasters is determined so that, no matter in which channel raster a CC is placed with a minimum channel bandwidth (CBW), there exists at least one synchronization raster in which the band of the SSB in the synchronization raster is included in the CBW.

[0023] If the UE fails to receive the SSB on a particular synchronization raster within a specific period of time, the length of which is up to the UE implementation, it attempts to receive the SSB on another synchronization raster.

[0024] During initial access, the order in which the UE searches for synchronization rasters is up to the UE implementation. For efficient searching, a Global Synchronization Channel Number (GSCN) is defined, and the UE is notified of the GSCN offset / GSCN range.

[0025] The frequencies to be searched for PSS / SSS other than at the time of initial access are instructed to the UE by the network (NW, for example, a base station).

[0026] For example, when instructed to measure RSRP / RSRQ / SINR for neighboring cells, the UE is instructed on the SSB frequency using the upper layer parameter "MeasObjectNR".

[0027] For example, when instructed to add a serving cell, the UE is instructed on the SSB frequency using the higher layer parameter "FrequencyInfoDL."

[0028] For example, a UE (in RRC_IDLE mode) is instructed on the SSB frequency using SIB4 (InterFreqCarrierFreqInfo).

[0029] A base station using beam correspondence transmits multiple SSBs using multiple beams (analog beams) for each SSB transmission period. The multiple SSBs may be referred to as SSB bursts. The multiple SSBs have multiple SSB indices. A UE that detects an SSB transmits a PRACH in the RACH occasion associated with that SSB index and receives an RAR in the RAR window.

[0030] Additionally, multiple PRACH formats (PRACH preamble formats) are being considered for NR. A Random Access (RA) preamble using each PRACH format includes a RACH OFDM symbol. Furthermore, the RA preamble may include at least one of a cyclic prefix (CP) and a guard period (GP). For example, PRACH formats 0 to 3 use a long sequence preamble sequence in the RACH OFDM symbol. PRACH formats A1 to A3, B1 to B4, C0, and C2 use a short sequence preamble sequence in the RACH OFDM symbol.

[0031] (Random Access Procedure) NR supports a random access procedure for establishing UL synchronization. The random access procedure includes contention-based random access (also called contention-based random access (CBRA)) and non-contention-based random access (non-CBRA, also called contention-free random access (CFRA)).

[0032] In contention-based random access (CBRA), a user terminal transmits a preamble randomly selected from a plurality of preambles (also called random access preambles, random access channel (Physical Random Access Channel (PRACH)), RACH preambles, etc.) defined for each cell. Contention-based random access is a user terminal-initiated random access procedure, and can be used, for example, at the time of initial access, at the start or restart of UL transmission, etc.

[0033] On the other hand, in non-contention random access (Non-CBRA, CFRA), a radio base station allocates a preamble to a user terminal uniquely via a downlink (DL) control channel (Physical Downlink Control Channel (PDCCH)), and the user terminal transmits the preamble allocated by the radio base station. Non-contention random access is a network-initiated random access procedure, and can be used, for example, at the time of handover, or when starting or resuming DL transmission (when starting or resuming UL transmission of DL retransmission instruction information), etc.

[0034] Fig. 1 is a diagram showing an example of contention-based random access. In Fig. 1, a user terminal receives in advance information (PRACH configuration information) indicating the configuration of a random access channel (PRACH) (PRACH configuration, RACH configuration) through system information (e.g., MIB (Material Information Block) and / or SIB (System Information Block)) or higher layer signaling (e.g., RRC (Radio Resource Control) signaling).

[0035] The PRACH configuration information can indicate, for example, multiple preambles (e.g., preamble formats) defined for each cell, time resources (e.g., system frame numbers, subframe numbers) and frequency resources (e.g., an offset (prach-FrequencyOffset) indicating the starting position of six resource blocks (PRBs: Physical Resource Blocks)) used for PRACH transmission, etc.

[0036] As shown in FIG. 1 , when a user terminal transitions from an idle (RRC_IDLE) state to an RRC connected (RRC_CONNECTED) state (e.g., at the time of initial access), when the user terminal is in an RRC connected state but UL synchronization has not been established (e.g., at the start or restart of UL transmission), etc., the user terminal randomly selects one of multiple preambles indicated by the PRACH configuration information and transmits the selected preamble via the PRACH (message 1, Msg. 1).

[0037] When the radio base station detects the preamble, it transmits a random access response (RAR) in response (message 2, Msg. 2). If the user terminal fails to receive the RAR within a predetermined period (RAR window) after transmitting the preamble, it increases the transmission power of the PRACH and retransmits (resends) the preamble. Increasing the transmission power during retransmission is also called power ramping.

[0038] Upon receiving the RAR, the user terminal adjusts the UL transmission timing based on the timing advance (TA) included in the RAR to establish UL synchronization. The user terminal also transmits a control message of the upper layer (L2 / L3: Layer 2 / Layer 3) using the UL resources specified by the UL grant included in the RAR (Message 3, Msg. 3). This control message includes the user terminal's identifier (UE-ID). The user terminal identifier may be, for example, a Cell-Radio Network Temporary Identifier (C-RNTI) if the user terminal is in an RRC connected state, or a UE-ID of an upper layer such as a System Architecture Evolution-Temporary Mobile Subscriber Identity (S-TMSI) if the user terminal is in an idle state.

[0039] The radio base station transmits a collision resolution message (message 4, Msg. 4) in response to a control message from a higher layer. The collision resolution message is transmitted based on the identifier of the user terminal included in the control message. A user terminal that successfully detects the collision resolution message transmits an acknowledgement (ACK) in Hybrid Automatic Repeat reQuest (HARQ) to the radio base station. This causes the user terminal in idle state to transition to an RRC connected state.

[0040] On the other hand, a user terminal that fails to detect the collision resolution message determines that a collision has occurred, reselects a preamble, and repeats the random access procedure of messages 1 to 4. When the radio base station detects that the collision has been resolved by an ACK from the user terminal, it transmits an UL grant to the user terminal. The user terminal transmits UL data using the UL resources allocated by the UL grant.

[0041] In the above-described contention-based random access, a user terminal can autonomously initiate a random access procedure when it desires to transmit UL data. Furthermore, after UL synchronization is established, the UL data is transmitted using UL resources that are specifically allocated to the user terminal by an UL grant, thereby enabling highly reliable UL transmission.

[0042] A random access procedure using transmission of Msg. 1, reception of Msg. 2, transmission of Msg. 3, and reception of Msg. 4 is also called a four-step random access procedure, a four-step random access procedure, a four-step RACH, or a four-step random access (RA).

[0043] In addition, NR supports a two-step random access procedure. The two-step random access procedure is also called a two-step random access procedure, a two-step RACH, or a two-step RA.

[0044] A two-step RA may consist of a first step of transmission from the UE to the base station and a second step of transmission from the base station to the UE (see Figure 2).

[0045] For example, in the first step, at least one of an UL signal and an UL channel (hereinafter also referred to as an UL signal / UL channel) including a preamble and a message may be transmitted from the UE to the base station. The preamble may be configured to fulfill the same role as message 1 (PRACH) in the existing random access procedure. The message may be configured to fulfill the same role as message 3 (PUSCH) in the existing random access procedure. The message transmitted in the first step may be referred to as message A (Msg. A).

[0046] In addition, in the second step, at least one of a DL signal and a DL channel (hereinafter also referred to as DL signal / DL channel) including a response and contention resolution may be transmitted from the base station to the UE. The response may be configured to fulfill the same role as message 2 (random access response (RAR) transmitted on PDSCH) in the existing random access procedure. The contention resolution may be configured to fulfill the same role as message 4 (PDSCH) in the existing random access procedure. Note that the message transmitted in the second step may be referred to as message B (Msg. B).

[0047] The user terminal may also transmit an ACK / NACK in response to Msg. B. This ACK / NACK may also be called an ACK / NACK (A / N) in response to Msg. B, a Msg. B ACK / NACK (A / N), a HARQ-ACK in response to Msg. B, a Msg. B HARQ-ACK, etc.

[0048] (Analysis) Future wireless communication systems (e.g., Beyond 5G and 6G) ​​have begun to be studied. One of the challenges for Beyond 5G and 6G is how to improve communication efficiency.

[0049] Here, existing specifications (e.g., NR) are designed on the premise of synchronization between a UE and a base station. In communications under existing specifications, a procedure for synchronization between a UE and a base station must be performed at the time of initial access. For example, the base station transmits a DL signal (e.g., SSB) for synchronization, and the UE receives the DL signal, thereby synchronizing the time / frequency resources of the UE and the base station.

[0050] On the other hand, in Beyond 5G and 6G, from the viewpoint of further improving the efficiency of communication, communication based on asynchronous communication between UE and base station (asynchronous communication, sync-free communication) is being considered. In particular, in the initial access procedure, it is being considered to simplify the procedures required for communication by eliminating the procedure for synchronization between UE and base station in the existing specifications. Asynchronous communication is expected to reduce overhead due to synchronization and maximize communication efficiency.

[0051] However, in the initial access procedure of asynchronous communication, it is not possible to accurately estimate / understand the time / frequency resources for transmitting / receiving signals / channels by the UE / base station, which may result in an inappropriate initial access procedure, resulting in a decrease in system performance, such as a decrease in communication throughput.

[0052] Therefore, the present inventors have conceived the following embodiments: According to one aspect of the present disclosure, initial access can be performed appropriately.

[0053] Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the drawings. Wireless communication methods according to the embodiments may be applied independently or in combination.

[0054] (Various Reinterpretations) In the present disclosure, a word enclosed in "( )" in a sentence may indicate an explanation of the word immediately preceding it (for example, an explanation of spelling), a paraphrase, a specific example, a supplementary explanation, etc. Furthermore, in the present disclosure, a word enclosed in "[ ]" in a sentence may be interpreted including the word in the meaning of the entire sentence, or may be interpreted excluding (ignoring) the word in the meaning of the entire sentence. Note that "( )" and "[ ]" may also be used for purposes / meanings other than those mentioned above.

[0055] In the present disclosure, "A / B" and "at least one of A and B" may be interpreted interchangeably. Also, in the present disclosure, "A / B / C" may mean "at least one of A, B, and C."

[0056] In the present disclosure, terms such as notify, activate, deactivate, indicate (or indicate), select, configure, update, and determine may be read interchangeably. In the present disclosure, terms such as support, control, controllable, operate, and operate may be read interchangeably.

[0057] In the present disclosure, Radio Resource Control (RRC), RRC parameters, RRC messages, higher layer parameters, fields, information elements (IEs), settings, etc. may be interchangeable. In the present disclosure, Medium Access Control (MAC) control elements (CEs), update commands, activation / deactivation commands, etc. may be interchangeable.

[0058] In the present disclosure, the higher layer signaling may be, for example, any one of Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information, other messages (e.g., messages from the core network such as positioning protocol (e.g., NR Positioning Protocol A (NRPPa) / LTE Positioning Protocol (LPP)) messages), or a combination thereof.

[0059] In the present disclosure, MAC signaling may use, for example, a MAC Control Element (MAC CE), a MAC Protocol Data Unit (PDU), etc. Broadcast information may be, for example, a Master Information Block (MIB), a System Information Block (SIB), Remaining Minimum System Information (RMSI), Other System Information (OSI), etc.

[0060] In the present disclosure, physical layer signaling may be, for example, Downlink Control Information (DCI), Uplink Control Information (UCI), and the like.

[0061] In the present disclosure, the terms drop, abort, cancel, puncture, rate match, postpone, do not transmit, etc. may be read interchangeably.

[0062] In the present disclosure, the terms carrier, band, cell, band, frequency [resource], etc. may be read interchangeably.

[0063] In the present disclosure, the terms radio frame, frame, subframe, slot, symbol, time (resource), timing, etc. may be read interchangeably.

[0064] In the present disclosure, random access (RA) procedure, RA, 4-step RA, 2-step RA, [4-step / 2-step] CBRA, [4-step / 2-step] CFRA, etc. may be read interchangeably.

[0065] In the present disclosure, synchronization signal (SS), primary synchronization signal (PSS), secondary synchronization signal (SSS), physical broadcast channel (PBCH), SS / PBCH block, synchronization signal block (SSB), [DL] signal, etc. may be interpreted interchangeably.

[0066] In the present disclosure, Msg. 1, PRACH, random access preamble, preamble, Msg. A, first message, first signal, [UL] signal, etc. may be read interchangeably.

[0067] In the present disclosure, Msg. 2, a PDCCH associated with an RAR, an RAR, a PDSCH including an RAR, a response [signal] to Msg. 1, Msg. B, Msg. B PDCCH / PDSCH, a response [signal] to Msg. A, a second message, a second signal, a [DL] signal, etc. may be interpreted as interchangeable.

[0068] In the present disclosure, Msg. 3, Msg. 3 PUSCH, PUSCH scheduled by RAR UL grant, response [signal] to Msg. 2, Msg. A, Msg. A PUSCH, third message, third signal, [UL] signal, etc. may be read interchangeably.

[0069] In the present disclosure, terms such as Msg. 4, a specific message indicating contention resolution, Msg. 4 PDCCH / PDSCH, a PDSCH including UE contention resolution identity, a response signal to Msg. 3, Msg. B, Msg. B PDCCH / PDSCH, a response signal to Msg. A, a fourth message, a fourth signal, and a DL signal may be interchangeable.

[0070] In the present disclosure, terms such as ACK / NACK (A / N) for Msg. 4, Msg. 4 ACK / NACK (A / N), HARQ-ACK for Msg. 4, Msg. 4 HARQ-ACK, response [signal] for Msg. 4, ACK / NACK (A / N) for Msg. B, Msg. B ACK / NACK (A / N), HARQ-ACK for Msg. B, Msg. B HARQ-ACK, response [signal] for Msg. B, fifth signal, [UL] signal, ACK / NACK (A / N), HARQ-ACK, UCI, etc. may be read interchangeably.

[0071] In the present disclosure, the terms ID, index, identifier, etc. may be read interchangeably.

[0072] In the present disclosure, the random access preamble ID, RAPID, RACH ID, etc. may be read interchangeably.

[0073] In the present disclosure, system information, system information block (SIB), SIB1, SIB based on SIB1 (SIBx (x is an integer of 2 or more)), etc. may be read interchangeably.

[0074] In the present disclosure, obtaining a timing advance (TA), measuring a TA, calculating a TA, deriving a TA, and determining a TA may be read interchangeably.

[0075] In the present disclosure, trigger signal, DL signal, DL channel, DL-RS, signal, instruction, setting, etc. may be read interchangeably.

[0076] (Wireless communication method) In the present disclosure, cases where a UE and a base station are not synchronized in time / frequency, where a UE and a base station are asynchronous in time / frequency resources, where a UE and a base station do not have a common understanding of time / frequency resources (for transmission and reception), where a UE does not receive an SSB (for synchronization), where an SSB received by a UE contains only specific information (information not related to synchronization (e.g., cell ID)), where a UE receives an SSB containing more limited information than an SSB of an existing specification (e.g., NR), where a predetermined period has passed since the reception of an SSB (for synchronization), where a predetermined timer started after the reception of an SSB (for synchronization) has expired, where a predetermined period has passed since the transmission of the (latest) PRACH, where a predetermined timer started after the transmission of the (latest) PRACH has expired, where a predetermined period has passed since the reception of the (latest) RAR, where a predetermined timer started after the reception of the (latest) RAR has expired, where a (latest) Msg. The cases where a predetermined period has elapsed since the transmission of (latest) Msg. 3, where a predetermined timer started after the transmission of (latest) Msg. 3 has expired, where a predetermined period has elapsed since the reception of (latest) Msg. 4, where a predetermined timer started after the reception of (latest) Msg. 4 has expired, where a predetermined period has elapsed since the transmission of (latest) Msg. 4 HARQ-ACK, where a predetermined timer started after the transmission of (latest) Msg. 4 HARQ-ACK has expired, where a predetermined period has elapsed since the completion of (latest) RA procedure, where a predetermined timer started after the completion of (latest) RA procedure has expired, and where time / frequency resources are not notified from the base station may be interpreted as being interchangeable.

[0077] In the present disclosure, the following cases are considered: a case where a UE and a base station are roughly synchronized; a case where a UE and a base station are asynchronous [in time / frequency [resources]]; a case where a UE and a base station are incomplete / partially synchronized [in time / frequency [resources]]; a case where a UE and a base station do not have a common understanding of time / frequency [resources] (for transmission and reception); a case where a UE and a base station have an incomplete / partial common understanding of time / frequency [resources] (for transmission and reception); a case where a UE does not receive SSB (for synchronization); a case where an SSB received by a UE contains specific information (information not related to synchronization); (e.g., cell ID), a case where the UE receives an SSB containing more limited information than an SSB of an existing specification (e.g., NR), a case where a predetermined period has elapsed since the reception of an SSB (for synchronization), a case where a predetermined timer started after the reception of an SSB (for synchronization) has expired, a case where a predetermined period has elapsed since the transmission of the (latest) PRACH, a case where a predetermined timer started after the transmission of the (latest) PRACH has expired, a case where a predetermined period has elapsed since the reception of the (latest) RAR, a case where a predetermined timer started after the reception of the (latest) RAR has expired, a case where a predetermined period has elapsed since the transmission of the (latest) Msg. 3, a case where a predetermined timer started after the transmission of the (latest) Msg. 3 has expired, a case where a predetermined period has elapsed since the reception of the (latest) Msg. 4, a case where a predetermined timer started after the reception of the (latest) Msg. 4 has expired, a case where a predetermined period has elapsed since the reception of the (latest) Msg. The case where a predetermined period has elapsed since the transmission of Msg. 4 HARQ-ACK, the case where a predetermined timer that is started after the transmission of the (latest) Msg. 4 HARQ-ACK has expired, the case where a predetermined period has elapsed since the completion of the (latest) RA procedure, the case where a predetermined timer that is started after the completion of the (latest) RA procedure has expired, the case where time / frequency resources are not notified from the base station, etc. may be interpreted as being interchangeable.

[0078] In the present disclosure, the UE may perform (coarse) frequency synchronization with the base station (may determine / determine frequency resources on which to transmit signals / channels) based on the synchronization raster.

[0079] In the present disclosure, the operation of detecting / measuring whether a signal exceeding a predetermined level (e.g., a predetermined power) is being transmitted from another transmission point, etc., before a transmission point (e.g., a base station, a UE, etc.) transmits a signal may be referred to as listening, listen before talk (LBT), clear channel assessment (CCA), carrier sense, etc.

[0080] In the present disclosure, the location of a UE / base station / network may be acquired / determined based on specific location information. In the present disclosure, the specific location information may be location information related to the UE / base station / network. The specific location information may include at least one of information (e.g., latitude, longitude, altitude) obtained using a positioning system (e.g., a satellite positioning system (Global Navigation Satellite System (GNSS), Global Positioning System (GPS), etc.)), information about a base station adjacent to (or serving) the UE (e.g., a base station / cell identifier (ID), a BS-UE distance, a direction / angle of the BS (UE) as seen from the UE (BS), coordinates of the BS (UE) as seen from the UE (BS) (e.g., X / Y / Z coordinates), etc.), a specific address of the UE (e.g., an Internet Protocol (IP) address), etc. The location information of the UE is not limited to information based on the location of the BS, but may also be information based on a specific point. The specific location information may also include information about its implementation (e.g., location / position / orientation of antennas, location / orientation of antenna panels, number of antennas, number of antenna panels, etc.).

[0081] In the present disclosure, the terms "a UE performing time / frequency synchronization based on a specific time / frequency resource," "a UE determining / judging a time / frequency resource for transmitting / receiving a specific signal / channel based on a specific time / frequency resource," "a UE transmitting / receiving a specific signal / channel using a time / frequency resource based on a specific time / frequency resource," "a UE performing time / frequency synchronization based on a specific time / frequency synchronization," "a UE determining / judging a time / frequency resource for transmitting / receiving a specific signal / channel based on a specific time / frequency synchronization," "a UE transmitting / receiving a specific signal / channel using a time / frequency resource based on a specific time / frequency synchronization," and so on may be read interchangeably.

[0082] The following embodiments will be described using initial access as an example, but may also be applied to operations other than initial access (e.g., operations after a predetermined period has elapsed since at least one of receiving an SSB and completing the latest RA procedure).

[0083] First Embodiment The first embodiment relates to PRACH transmission in the case where a UE and a base station are unsynchronized and in the case where a UE and a base station are roughly synchronized.

[0084] As shown in FIG. 3, in these cases, the UE may transmit the PRACH without receiving an SSB for synchronization.

[0085] As shown in Figure 4, in these cases, the UE may transmit the PRACH without receiving the SSB for synchronization, and then receive the SSB for synchronization after the PRACH transmission. In this case, the SSB may be received in the period from the transmission of the PRACH to the reception of the RAR, in the period from the reception of the RAR to the transmission of Msg. 3, in the period from the transmission of Msg. 3 to the reception of Msg. 4, in the period from the reception of Msg. 4 to the transmission of Msg. 4 HARQ-ACK, in the period from the transmission of the PRACH to the transmission of Msg. 3, in the period from the reception of the RAR to the reception of Msg. 4, in the period from the transmission of Msg. 3 to the reception of Msg. 4 HARQ-ACK, or in the period from the transmission of the PRACH to the transmission of Msg. The RA may be received during the period from reception of the RAR to transmission of Msg. 4 HARQ-ACK, during the period from transmission of the PRACH to transmission of Msg. 4 HARQ-ACK, or during a specific period after transmission of Msg. 4 HARQ-ACK (for example, the period until the start of the next RA procedure).

[0086] <<Embodiment 1.1>> A UE may transmit a PRACH without time / frequency synchronization with a base station.

[0087] The UE may transmit the PRACH at a specific frequency. The specific frequency may be a frequency defined by a specification, a frequency notified by an SIB / RRC / trigger signal, or a frequency configured by another RAT / base station / cell.

[0088] In embodiment 1.1, the UE may transmit the PRACH (may determine the transmission timing of the PRACH) based on at least one of the following methods 1-1-1 to 1-1-3. At least one of the following methods 1-1-1 to 1-1-3 may be suitably applied when the UE is not notified of time resources by the base station.

[0089] (Method 1-1-1) The UE may correct / determine the transmission timing of the PRACH based on the timing advance (TA).

[0090] The UE may estimate / calculate the TA based on the base station's location and its own location (UE's location) at the time of transmitting the PRACH.

[0091] The TA may be defined by specifications. For example, in NR, when the subcarrier spacing (SCS) is 30 kHz, the distance of one TA is approximately 78 m. Therefore, the cell radius may be less than approximately 39 m. In other words, a specific TA may be defined for each subcarrier spacing used for transmitting the PRACH.

[0092] (Method 1-1-2) The UE may perform CFRA. In this case, the ID (RAPID) of the random access preamble may be defined by the specification, may be notified by SIB / RRC, or may be randomly generated. Furthermore, the PRACH format may be randomly generated or may be defined by the specification.

[0093] (Method 1-1-3) The UE may perform CBRA. In this case, the ID (RAPID) of the random access preamble may be defined by the specification, may be notified by SIB / RRC, or may be randomly generated. In addition, the PRACH format may be randomly generated or may be defined by the specification.

[0094] When the UE performs carrier sensing, either method 1-1-1 or method 1-1-2 may be selected based on the relationship between the reception timing of the radio frame and the slot.

[0095] When the UE performs carrier sensing and the reception timing of the radio frame at the base station is determined based on a slot (slotted aloha), Method 1-1-1 may be applied. In this case, the base station may receive the radio frame in a specific slot. This allows the base station to assume reception of the PRACH only in the specific slot, thereby reducing the processing load of the base station.

[0096] When the UE performs carrier sensing and the reception timing of the radio frame at the base station is not determined on a slot, Method 1-1-2 may be applied. In this case, the base station may receive the frame at any slot. This eliminates the need for the UE to correct the transmission timing of the PRACH, thereby reducing the processing load on the UE.

[0097] If the UE does not perform carrier sensing, method 1-1-3 may be applied, in which case the UE does not perform carrier sensing, thereby reducing the processing load on the UE.

[0098] In this way, the transmission method for PRACH transmission (e.g., Method 1-1-1 / Method 1-1-2 / Method 1-1-3) may be determined based on at least one of whether carrier sense is applied and the relationship between the reception timing of the radio frame and the slot.

[0099] Whether or not the UE performs carrier sensing may be notified by an SIB / RRC / trigger signal, or may depend on the implementation of the UE.

[0100] When a frequency resource is notified to the UE by SIB / RRC, the UE may perform frequency synchronization based on the frequency resource (or may transmit PRACH on a frequency resource based on the frequency resource).

[0101] According to the above-described embodiment 1.1, even if the UE is not time / frequency synchronized with the base station, the UE can appropriately determine / judge the time / frequency resource for transmitting the PRACH.

[0102] <<Embodiment 1.2>> The UE may transmit the PRACH in the notified time / frequency resources even when it is coarsely synchronized with the base station.

[0103] In embodiment 1.2, the UE may transmit the PRACH (or determine the timing to transmit the PRACH) based on at least one of the following methods 1-2-1 to 1-2-3.

[0104] (Method 1-2-1) The UE may transmit the PRACH based on a radio frame synchronized using specific location information (for example, GNSS) (or may transmit the PRACH in a time resource based on that radio frame).

[0105] In method 1-2-1, when a frequency resource is notified to the UE by SIB / RRC, the UE may perform frequency synchronization based on the frequency resource (or may transmit the PRACH on a frequency resource based on the frequency resource). Alternatively, the UE may transmit the PRACH on a frequency resource defined by a specification.

[0106] In method 1-2-1, the UE may calculate the TA when transmitting the PRACH (before transmitting the PRACH) and change / determine the transmission timing (time resource) of the PRACH (based on the TA).

[0107] (Method 1-2-2) When a PRACH resource is notified to a UE by SIB / RRC, the UE may perform time / frequency synchronization based on the radio frame of the UE synchronized with the notified (PRACH) resource (or may transmit the PRACH in the time / frequency resource based on the radio frame).

[0108] In method 1-2-2, when the UE retransmits the PRACH, the UE may receive the PRACH resource again from the base station for radio frame synchronization, and the UE may perform time / frequency synchronization based on the radio frame of the synchronized UE for the re-received PRACH resource (or transmit the PRACH in the time / frequency resource based on the radio frame).

[0109] In method 1-2-2, when the UE retransmits the PRACH, the UE may perform time / frequency synchronization based on the radio frame of the UE that was synchronized with the previously notified PRACH resource (the UE may transmit the PRACH in a time / frequency resource based on that radio frame).

[0110] In method 1-2-2, if PRACH retransmission fails a predetermined number of times (e.g., one or more times), the UE may receive PRACH resources again from the base station for radio frame synchronization. The UE may perform time / frequency synchronization on the re-received PRACH resources based on the synchronized radio frame of the UE (or transmit the PRACH on time / frequency resources based on the radio frame).

[0111] (Method 1-2-3) A new PRACH format (extend CP RACH format) in which CP / GP is increased compared to the existing PRACH format may be defined by specifications and may be notified to the UE via SIB / RRC. Alternatively, the CP / GP may be variable and may be notified to the UE via SIB / RRC.

[0112] According to the above-described embodiment 1.2, even if the UE is roughly synchronized with the base station in the notified time / frequency resource, the UE can control synchronization for the PRACH. Also, the UE can appropriately determine / judge the time / frequency resource for transmitting the PRACH.

[0113] Second Embodiment The second embodiment relates to transmission of at least one of Msg. 3 and HARQ-ACK for Msg. 4 (hereinafter also referred to as Msg. 4 HARQ-ACK) in the case where a UE and a base station are roughly synchronized.

[0114] As shown in Figure 5, the UE may transmit Msg. 3 / Msg. 4 HARQ-ACK without receiving an SSB for synchronization.

[0115] As shown in Figure 6, the UE may transmit Msg. 3 without receiving an SSB for synchronization, and then receive the SSB for synchronization after transmitting Msg. 3. In this case, the SSB may be received in the period from the transmission of Msg. 3 to the reception of Msg. 4, in the period from the reception of Msg. 4 to the transmission of Msg. 4 HARQ-ACK, in the period from the transmission of Msg. 3 to the transmission of Msg. 4 HARQ-ACK, or in a specific period after the transmission of Msg. 4 HARQ-ACK (e.g., until the start of the next RA procedure).

[0116] As shown in Figure 7, the UE may transmit Msg. 4 HARQ-ACK without receiving the SSB for synchronization and then receive the SSB for synchronization after the transmission of Msg. 4 HARQ-ACK, in which case the SSB may be received within a certain period of time after the transmission of Msg. 4 HARQ-ACK (e.g., until the start of the next RA procedure).

[0117] The UE may transmit Msg. 3 / Msg. 4 HARQ-ACK in the indicated time / frequency resources even if it is coarsely synchronized with the base station.

[0118] The UE may transmit Msg. 3 / Msg. 4 HARQ-ACK according to at least one of the following methods 2-1 to 2-4.

[0119] (Method 2-1) The UE may transmit Msg. 3 / Msg. 4 HARQ-ACK based on its own radio frame synchronized using specific location information (e.g., GNSS) (or may transmit Msg. 3 / Msg. 4 HARQ-ACK in time / frequency resources based on that radio frame).

[0120] In method 2-1, the UE may perform frequency synchronization based on the frequency resource when it acquires PRACH information (for example, the frequency resource (PRACH resource) notified by the SIB / RRC / trigger signal in the first embodiment) (and may transmit Msg. 3 / Msg. 4 HARQ-ACK in a frequency resource based on that frequency resource). Alternatively, the UE may transmit Msg. 3 / Msg. 4 HARQ-ACK in a frequency resource defined by the specifications.

[0121] In Method 2-1, the UE may calculate the TA when transmitting Msg. 3 / Msg. 4 HARQ-ACK (before transmitting Msg. 3 / Msg. 4 HARQ-ACK) and change / determine the transmission timing (time resource) of Msg. 3 / Msg. 4 HARQ-ACK (based on the TA). The TA may be obtained in the same manner as in the first embodiment (e.g., Method 1-1-1).

[0122] (Method 2-2) The UE may perform time / frequency synchronization based on the time / frequency synchronization when receiving the RAR (Msg. 2) / Msg. 4 (and may determine / judge the time / frequency resources for transmitting Msg. 3 / Msg. 4 HARQ-ACK based on the time / frequency synchronization when receiving the RAR / Msg. 4).

[0123] When the UE receives an RAR after a predetermined period has elapsed since the transmission of the PRACH (or after a predetermined timer that starts after the transmission of the PRACH has expired), the UE may perform time / frequency synchronization based on the time / frequency synchronization when the RAR is received (and may determine / judge the time / frequency resources for transmitting Msg.3 / Msg.4 HARQ-ACK based on the time / frequency synchronization when the RAR is received).

[0124] When the UE receives Msg. 4 after a predetermined period has elapsed since the transmission of the PRACH (or after a predetermined timer that starts after the transmission of the PRACH has expired), the UE may perform time / frequency synchronization based on the time / frequency synchronization at the time of receiving Msg. 4 (and may determine / judge the time / frequency resource for transmitting Msg. 4 HARQ-ACK based on the time / frequency synchronization at the time of receiving Msg. 4).

[0125] When the UE receives Msg. 4 after a predetermined period has elapsed since the transmission of Msg. 3 (or after a predetermined timer that starts after the transmission of Msg. 3 has expired), the UE may perform time / frequency synchronization based on the time / frequency synchronization at the time of receiving Msg. 4 (and may determine / judge the time / frequency resource for transmitting Msg. 4 HARQ-ACK based on the time / frequency synchronization at the time of receiving Msg. 4).

[0126] Generally, the accuracy of synchronization between a UE and a base station decreases / attenuates over time. Therefore, when RAR / Msg.4 is retransmitted, time / frequency synchronization may be performed each time (each time RAR / Msg.4 is retransmitted). (The time / frequency resource for transmitting Msg.3 / Msg.4 HARQ-ACK may be determined / judged based on the time / frequency synchronization performed each time RAR / Msg.4 is retransmitted.)

[0127] The same preamble may be inserted / added to RAR / Msg. 4 every time, or an RS based on RAPID may be mapped to a resource.

[0128] (Method 2-3) The UE may apply / apply / add a preamble signal for time / frequency synchronization immediately before transmitting Msg. 3 / Msg. 4 HARQ-ACK. The timing may be specified by the specification (e.g., the latest symbol / slot before the symbol / slot where the transmission of Msg. 3 / Msg. 4 HARQ-ACK starts).

[0129] The preamble signal may use the PRACH signal as is, may be punctured / repeated from an existing sequence length so as to use the same frequency resource as Msg. 3, or may have a new sequence length defined.

[0130] (Method 2-4) The CP ratio may be different between UL and DL. The CP length / number of OFDM symbols may be notified by SIB / RRC / RAR / MAC CE.

[0131] The synchronization accuracy of the UE may be notified / reported by the UE capability information. The CP length / number of OFDM symbols may be changed / determined based on the synchronization accuracy (supported / reported by the UE).

[0132] According to the second embodiment described above, even if the UE is roughly synchronized with the base station in the notified time / frequency resources, the UE can control synchronization for Msg. 3 / Msg. 4 HARQ-ACK. Furthermore, the UE can appropriately determine / judge the time / frequency resources for transmitting Msg. 3 / Msg. 4 HARQ-ACK.

[0133] <Variations> The above-described embodiments may be applied to two-step RA. In this case, PRACH / Msg. 3 in the above-described embodiments may be replaced with Msg. A, RAR / Msg. 4 in the above-described embodiments may be replaced with Msg. B, and Msg. 4 HARQ-ACK in the above-described embodiments may be replaced with Msg. B HARQ-ACK.

[0134] <Supplementary Information> <<Notification of Information to UE>> In the above-described embodiments, notification of any information to the UE [from a Network (NW) (e.g., a Base Station (BS))] (in other words, reception of any information from the BS by the UE) may be performed using physical layer signaling (e.g., DCI), higher layer signaling (e.g., RRC signaling, MAC CE), a specific signal / channel (e.g., PDCCH, PDSCH, reference signal), or a combination thereof.

[0135] When the notification is performed by a MAC CE, the MAC CE may be identified by including a new Logical Channel ID (LCID) in the MAC subheader, which is not defined in existing standards.

[0136] When the notification is made by DCI, the notification may be made by a specific field of the DCI, a Radio Network Temporary Identifier (RNTI) used to scramble Cyclic Redundancy Check (CRC) bits assigned to the DCI, the format of the DCI, etc.

[0137] Furthermore, notification of any information to the UE in the above embodiments may be performed periodically, semi-persistently, or aperiodically.

[0138] <<Notification of Information from UE>> In the above-described embodiments, notification of any information from the UE [to the NW] (in other words, transmission / report of any information from the UE to the BS) may be performed using physical layer signaling (e.g., UCI), higher layer signaling (e.g., RRC signaling, MAC CE), a specific signal / channel (e.g., PUCCH, PUSCH, PRACH, reference signal), or a combination thereof.

[0139] When the notification is performed by a MAC CE, the MAC CE may be identified by including a new LCID, which is not defined in existing standards, in the MAC subheader.

[0140] If the notification is made by UCI, the notification may be transmitted using PUCCH or PUSCH.

[0141] Furthermore, any information in the above-described embodiments may be notified from the UE periodically, semi-persistently, or aperiodically.

[0142] <<Regarding Application of Each Embodiment>> In a UE / BS, specific (one or more) processes / operations / controls / assumptions / information for at least one of the above-mentioned embodiments may be applied (used) when one or more of the following conditions are met: - a higher layer parameter indicating the specific processes / operations / controls / assumptions / information is configured; - the specific processes / operations / controls / assumptions / information is determined based on related higher layer parameters; - the specific processes / operations / controls / assumptions / information is specified / activated / triggered by a MAC CE / DCI / UCI / resource / channel / RS; - a specific UE capability indicating (or related to) the specific processes / operations / controls / assumptions / information is reported or supported; - the application of the specific processes / operations / controls / assumptions / information is determined based on specific conditions.

[0143] The specific UE capability may indicate at least one of the following: - Supporting the specific process / operation / control / assumption / information; - Supporting asynchronous communication; - Information regarding the synchronization accuracy of the UE.

[0144] Furthermore, the above-mentioned specific UE capability may be a capability that is applied across all frequencies (commonly regardless of frequency), or may be a capability for each frequency (e.g., one or a combination of a cell, a band, a band combination, a BWP, a component carrier, etc.), or may be a capability for each frequency range (e.g., Frequency Range 1 (FR1), FR2, FR3, FR4, FR5, FR2-1, FR2-2), or may be a capability for each subcarrier spacing (SubCarrier Spacing (SCS)), or may be a capability for each Feature Set (FS) or Feature Set Per Component-carrier (FSPC).

[0145] Furthermore, the specific UE capability may be a capability that is applied to all duplexing methods (commonly regardless of the duplexing method), or may be a capability for each duplexing method (e.g., Time Division Duplex (TDD) or Frequency Division Duplex (FDD)).

[0146] If the above conditions are not met, the UE / BS may follow the behavior specified in existing 3GPP releases.

[0147] (Supplementary Notes) The following inventions are supplementary notes regarding one embodiment of the present disclosure (particularly the first embodiment). [Supplementary Note 1] A terminal having: a controller that controls transmission timing of a physical random access channel (PRACH) without receiving a synchronization signal block (SSB); and a transmitter that transmits the PRACH based on the transmission timing. [Supplementary Note 2] The terminal according to Supplementary Note 1, wherein the controller controls the transmission timing based on whether or not to perform carrier sensing. [Supplementary Note 3] The terminal according to Supplementary Note 1 or Supplementary Note 2, wherein the controller controls the transmission timing based on specific location information. [Supplementary Note 4] The terminal according to any one of Supplementary Notes 1 to 3, wherein, when a resource for the PRACH is notified, the controller controls the transmission timing based on the resource.

[0148] (Supplementary Notes) The following inventions are supplementary notes regarding one embodiment of the present disclosure (particularly, the second embodiment). [Supplementary Note 1] A terminal having: a control unit that controls synchronization for a response to at least one of a random access response (RAR) and a specific message indicating contention resolution without receiving a synchronization signal block (SSB); and a transmission unit that transmits the response based on the synchronization. [Supplementary Note 2] The terminal described in Supplementary Note 1, wherein the control unit controls the synchronization based on a timing advance (TA). [Supplementary Note 3] The terminal described in Supplementary Note 1 or Supplementary Note 2, wherein the control unit controls the synchronization for each retransmission when at least one of the RAR and the specific message is retransmitted. [Supplementary Note 4] The terminal described in any of Supplementary Notes 1 to 3, wherein the control unit applies a preamble signal for synchronizing at least one of time and frequency to the response.

[0149] (Wireless Communication System) The configuration of a wireless communication system according to an embodiment of the present disclosure will be described below. In this wireless communication system, communication is performed using any one of the wireless communication methods according to the above embodiments of the present disclosure or a combination thereof.

[0150] 8 is a diagram illustrating an example of a schematic configuration of a wireless communication system according to an embodiment. The wireless communication system 1 (which may be simply referred to as system 1) may be a system that realizes communication using Long Term Evolution (LTE) or 5th generation mobile communication system New Radio (5G NR) specified by the Third Generation Partnership Project (3GPP).

[0151] The wireless communication system 1 may also support dual connectivity between multiple Radio Access Technologies (RATs) (Multi-RAT Dual Connectivity (MR-DC)). MR-DC may include dual connectivity between LTE (Evolved Universal Terrestrial Radio Access (E-UTRA)) and NR (E-UTRA-NR Dual Connectivity (EN-DC)), dual connectivity between NR and LTE (NR-E-UTRA Dual Connectivity (NE-DC)), etc.

[0152] In EN-DC, the LTE (E-UTRA) base station (eNB) is the master node (Master Node (MN)), and the NR base station (gNB) is the secondary node (Secondary Node (SN)). In NE-DC, the NR base station (gNB) is the MN, and the LTE (E-UTRA) base station (eNB) is the SN.

[0153] The wireless communication system 1 may support dual connectivity between multiple base stations within the same RAT (for example, dual connectivity in which both the MN and SN are NR base stations (gNBs) (NR-NR Dual Connectivity (NN-DC))).

[0154] The wireless communication system 1 may include a base station 11 that forms a macrocell C1 with a relatively wide coverage, and base stations 12 (12a-12c) that are located within the macrocell C1 and form small cells C2 that are smaller than the macrocell C1. A user terminal 20 may be located within at least one of the cells. The location, number, shape, size, etc. of each cell and user terminal 20 are not limited to the embodiment shown in the figure. Hereinafter, when there is no need to distinguish between the base stations 11 and 12, they will be collectively referred to as the base station 10.

[0155] The wireless communication system 1 may utilize multi-input multi-output (MIMO). For example, one cell may be formed by one antenna / base station 10, or may be formed by multiple antennas / base stations 10. One [virtual] cell (which may be called, for example, a supercell) may be composed of multiple [virtual] cells (which may be called, for example, subcells). A supercell may correspond to a cell with a fixed physical range, and a subcell may correspond to a cell with a quasi-static / dynamically variable physical range. In this case, the wireless communication system 1 may be called a cell-free system.

[0156] The user terminal 20 may be connected to at least one of the multiple base stations 10. The user terminal 20 may utilize at least one of carrier aggregation (CA) using multiple component carriers (CCs) and dual connectivity (DC).

[0157] Each CC may be included in at least one of a first frequency band (Frequency Range 1 (FR1)) and a second frequency band (Frequency Range 2 (FR2)). The macro cell C1 may be included in FR1, and the small cell C2 may be included in FR2. For example, FR1 may be a frequency band of 6 GHz or less (sub-6 GHz), and FR2 may be a frequency band higher than 24 GHz (above-24 GHz). Note that the frequency bands and definitions of FR1 and FR2 are not limited to these, and for example, FR1 may correspond to a higher frequency band than FR2.

[0158] Furthermore, the user terminal 20 may perform communication using at least one of time division duplex (TDD) and frequency division duplex (FDD) in each CC.

[0159] The multiple base stations 10 may be connected by wire (e.g., optical fiber compliant with the Common Public Radio Interface (CPRI), an X2 / Xn interface, etc.) or wirelessly (e.g., NR communication). For example, when NR communication is used as a backhaul between the base stations 11 and 12, the base station 11 corresponding to the upper station may be called an Integrated Access Backhaul (IAB) donor, and the base station 12 corresponding to the relay station (relay) may be called an IAB node.

[0160] The base station 10 may be connected to the core network 30 directly or via another base station 10. The core network 30 may include, for example, at least one of an Evolved Packet Core (EPC), a 5G Core Network (5GCN), a Next Generation Core (NGC), and the like.

[0161] The core network 30 may include network functions (Network Functions (NF)) such as a User Plane Function (UPF), an Access and Mobility management Function (AMF), a Session Management Function (SMF), a Unified Data Management (UDM), an Application Function (AF), a Data Network (DN), a Location Management Function (LMF), and Operation, Administration and Maintenance (Management) (OAM). A single network node may provide multiple functions. Communication with an external network (e.g., the Internet) may also be performed via the DN.

[0162] The user terminal 20 may be a terminal that supports at least one of communication methods such as LTE, LTE-A, and 5G.

[0163] An Orthogonal Frequency Division Multiplexing (OFDM)-based radio access scheme may be used in the wireless communication system 1. For example, Cyclic Prefix OFDM (CP-OFDM), Discrete Fourier Transform Spread OFDM (DFT-s-OFDM), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), or the like may be used in at least one of the downlink (DL) and uplink (UL).

[0164] The radio access scheme may also be called a waveform. Note that in the wireless communication system 1, other radio access schemes (e.g., other single-carrier transmission schemes, other multi-carrier transmission schemes) may be used as the UL and DL radio access schemes.

[0165] In the wireless communication system 1, a downlink shared channel (Physical Downlink Shared Channel (PDSCH)) shared by each user terminal 20, a broadcast channel (Physical Broadcast Channel (PBCH)), a downlink control channel (Physical Downlink Control Channel (PDCCH)), etc. may be used as the downlink channel.

[0166] Furthermore, in the wireless communication system 1, an uplink shared channel (Physical Uplink Shared Channel (PUSCH)) shared by each user terminal 20, an uplink control channel (Physical Uplink Control Channel (PUCCH)), a random access channel (Physical Random Access Channel (PRACH)), or the like may be used as an uplink channel.

[0167] The PDSCH transmits user data, higher layer control information, a System Information Block (SIB), etc. The PUSCH may transmit user data, higher layer control information, etc. Furthermore, the PBCH may transmit a Master Information Block (MIB).

[0168] Lower layer control information may be transmitted by the PDCCH. The lower layer control information may include, for example, Downlink Control Information (DCI) including scheduling information for at least one of the PDSCH and the PUSCH.

[0169] Note that the DCI for scheduling the PDSCH may be referred to as a DL assignment, a DL DCI, etc., and the DCI for scheduling the PUSCH may be referred to as a UL grant, a UL DCI, etc. Note that the PDSCH may be replaced with DL data, and the PUSCH may be replaced with UL data.

[0170] A control resource set (CORESET) and a search space may be used to detect the PDCCH. The CORESET corresponds to resources for searching for DCI. The search space corresponds to a search region and a search method for PDCCH candidates. One CORESET may be associated with one or more search spaces. The UE may monitor the CORESET associated with a certain search space based on the search space configuration.

[0171] One search space may correspond to PDCCH candidates corresponding to one or more aggregation levels. One or more search spaces may be referred to as a search space set. Note that the terms "search space," "search space set," "search space configuration," "search space set configuration," "CORESET," "CORESET configuration," and the like in the present disclosure may be read interchangeably.

[0172] The PUCCH may transmit uplink control information (UCI) including at least one of channel state information (CSI), delivery confirmation information (which may be called, for example, Hybrid Automatic Repeat reQuest ACKnowledgement (HARQ-ACK), ACK / NACK, etc.), and scheduling request (SR). The PRACH may transmit a random access preamble for establishing a connection with a cell.

[0173] In the present disclosure, downlink, uplink, etc. may be expressed without adding "link." Also, various channels may be expressed without adding "Physical" to the beginning.

[0174] In the wireless communication system 1, a synchronization signal (SS), a downlink reference signal (DL-RS), etc. may be transmitted. In the wireless communication system 1, as the DL-RS, a cell-specific reference signal (CRS), a channel state information reference signal (CSI-RS), a demodulation reference signal (DMRS), a positioning reference signal (PRS), a phase tracking reference signal (PTRS), etc. may be transmitted.

[0175] The synchronization signal may be, for example, at least one of a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS). A signal block including an SS (PSS, SSS) and a PBCH (and a DMRS for the PBCH) may be referred to as an SS / PBCH block, an SS Block (SSB), or the like. Note that the SS, SSB, and the like may also be referred to as a reference signal.

[0176] Furthermore, in the wireless communication system 1, a sounding reference signal (SRS), a demodulation reference signal (DMRS), or the like may be transmitted as an uplink reference signal (UL-RS). Note that the DMRS may also be called a user equipment-specific reference signal (UE-specific reference signal).

[0177] (Base Station) Fig. 9 is a diagram showing an example of the configuration of a base station according to an embodiment. The base station 10 includes a control unit 110, a transceiver unit 120, a transceiver antenna 130, and a transmission line interface 140. Note that the base station may include one or more of each of the control unit 110, the transceiver unit 120, the transceiver antenna 130, and the transmission line interface 140.

[0178] In this example, the functional blocks of the characteristic parts of the present embodiment are mainly shown, and it may be assumed that the base station 10 also has other functional blocks necessary for wireless communication. Some of the processing of each unit described below may be omitted.

[0179] The control unit 110 performs overall control of the base station 10. The control unit 110 can be configured from a controller, a control circuit, and the like that are explained based on common understanding in the technical field to which the present disclosure relates.

[0180] The control unit 110 may control signal generation, scheduling (e.g., resource allocation, mapping), etc. The control unit 110 may control transmission and reception using the transceiver unit 120, the transceiver antenna 130, and the transmission path interface 140, measurement, etc. The control unit 110 may generate data, control information, sequences, etc. to be transmitted as signals, and transfer them to the transceiver unit 120. The control unit 110 may perform call processing (setting up, releasing, etc.) of communication channels, status management of the base station 10, management of radio resources, etc.

[0181] The transceiver unit 120 may include a baseband unit 121, a radio frequency (RF) unit 122, and a measurement unit 123. The baseband unit 121 may include a transmission processing unit 1211 and a reception processing unit 1212. The transceiver unit 120 may be configured with a transmitter / receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transceiver circuit, etc., which are described based on common understanding in the technical field related to the present disclosure.

[0182] The transmitting / receiving unit 120 may be configured as an integrated transmitting / receiving unit, or may be configured from a transmitting unit and a receiving unit. The transmitting unit may be configured from a transmission processing unit 1211 and an RF unit 122. The receiving unit may be configured from a reception processing unit 1212, the RF unit 122, and a measurement unit 123.

[0183] The transmitting and receiving antenna 130 can be configured from an antenna described based on common understanding in the technical field to which the present disclosure relates, such as an array antenna.

[0184] The transceiver 120 may transmit the above-mentioned downlink channel, synchronization signal, downlink reference signal, etc. The transceiver 120 may receive the above-mentioned uplink channel, uplink reference signal, etc.

[0185] The transceiver 120 may form at least one of the transmit beam and the receive beam using digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), or the like.

[0186] The transmitter / receiver unit 120 (transmission processing unit 1211) may perform Packet Data Convergence Protocol (PDCP) layer processing, Radio Link Control (RLC) layer processing (e.g., RLC retransmission control), Medium Access Control (MAC) layer processing (e.g., HARQ retransmission control), etc. on data, control information, etc. obtained from the control unit 110, and generate a bit string to be transmitted.

[0187] The transmitter / receiver unit 120 (transmission processing unit 1211) may perform transmission processing such as channel coding (which may include error correction coding), modulation, mapping, filtering, Discrete Fourier Transform (DFT) processing (if necessary), Inverse Fast Fourier Transform (IFFT) processing, precoding, and digital-to-analog conversion on the bit string to be transmitted, and output a baseband signal.

[0188] The transceiver unit 120 (RF unit 122) may perform modulation, filtering, amplification, etc. on the baseband signal to a radio frequency band, and transmit the radio frequency band signal via the transceiver antenna 130.

[0189] On the other hand, the transmitting / receiving unit 120 (RF unit 122) may perform amplification, filtering, demodulation to a baseband signal, etc. on the radio frequency band signal received by the transmitting / receiving antenna 130.

[0190] The transceiver 120 (reception processing unit 1212) may apply reception processing such as analog-to-digital conversion, Fast Fourier Transform (FFT) processing, Inverse Discrete Fourier Transform (IDFT) processing (if necessary), filtering, demapping, demodulation, decoding (which may include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing to the acquired baseband signal, thereby acquiring user data, etc.

[0191] The transceiver 120 (measurement unit 123) may perform measurements on the received signal. For example, the measurement unit 123 may perform Radio Resource Management (RRM) measurements, Channel State Information (CSI) measurements, etc. based on the received signal. The measurement unit 123 may measure received power (e.g., Reference Signal Received Power (RSRP)), received quality (e.g., Reference Signal Received Quality (RSRQ), Signal to Interference plus Noise Ratio (SINR), Signal to Noise Ratio (SNR)), signal strength (e.g., Received Signal Strength Indicator (RSSI)), propagation path information (e.g., CSI), etc. The measurement results may be output to the control unit 110.

[0192] The transmission path interface 140 may transmit and receive signals (backhaul signaling) between devices included in the core network 30 (e.g., network nodes that provide NF), other base stations 10, etc., and may acquire and transmit user data (user plane data), control plane data, etc. for the user terminal 20.

[0193] The transmitting section and receiving section of the base station 10 in the present disclosure may be configured by at least one of the transmitting / receiving section 120, the transmitting / receiving antenna 130, and the transmission path interface 140.

[0194] The base station 10 may be separated into three elements: a radio unit (RU), a distributed unit (DU), and a central unit (CU). For example, the RU may implement RF processing (digital beamforming, digital-to-analog conversion, analog beamforming, etc.) and lower-level functions of the physical layer (precoding, IFFT, FFT, etc.). The DU may implement higher-level functions of the physical layer (coding to resource element mapping, etc.), MAC layer functions, and RLC layer functions. The CU may implement the functions of the PDCP layer, Service Data Adaptation Protocol (SDAP) layer, and RRC layer.

[0195] In the present disclosure, the base station 10 may include a single device that realizes all of the functions of the RU, DU, and CU, or may include multiple devices that each realize some of the functions of the RU, DU, and CU and are connected to each other. In the present disclosure, the base station 10 may be interchangeably read as RU / DU / CU.

[0196] The control unit 110 may control the transmission timing of the physical random access channel (PRACH) of the user terminal 20 without transmitting a synchronization signal block (SSB).

[0197] The transceiver 120 may receive the PRACH, which is transmitted based on the transmission timing.

[0198] The control unit 110 may control synchronization for a response to at least one of a random access response (RAR) and a specific message indicating contention resolution without transmitting a synchronization signal block (SSB).

[0199] The transmitting / receiving unit 120 may receive the response that is transmitted based on the synchronization.

[0200] (User Terminal) Fig. 10 is a diagram showing an example of the configuration of a user terminal according to one embodiment. The user terminal 20 includes a control unit 210, a transceiver unit 220, and a transceiver antenna 230. Note that the user terminal 20 may include one or more of each of the control unit 210, the transceiver unit 220, and the transceiver antenna 230.

[0201] In this example, the functional blocks of the characteristic parts of the present embodiment are mainly shown, and it may be assumed that the user terminal 20 also has other functional blocks necessary for wireless communication. Some of the processing of each unit described below may be omitted.

[0202] The control unit 210 performs overall control of the user terminal 20. The control unit 210 can be configured from a controller, a control circuit, etc., which are described based on common understanding in the technical field to which the present disclosure relates.

[0203] The control unit 210 may control signal generation, mapping, etc. The control unit 210 may control transmission and reception, measurement, etc. using the transceiver unit 220 and the transceiver antenna 230. The control unit 210 may generate data, control information, sequences, etc. to be transmitted as signals and transfer them to the transceiver unit 220.

[0204] The transceiver unit 220 may include a baseband unit 221, an RF unit 222, and a measurement unit 223. The baseband unit 221 may include a transmission processing unit 2211 and a reception processing unit 2212. The transceiver unit 220 may be configured with a transmitter / receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transceiver circuit, etc., which are described based on common understanding in the technical field related to the present disclosure.

[0205] The transmitting / receiving unit 220 may be configured as an integrated transmitting / receiving unit, or may be composed of a transmitting unit and a receiving unit. The transmitting unit may be composed of a transmission processing unit 2211 and an RF unit 222. The receiving unit may be composed of a reception processing unit 2212, an RF unit 222, and a measurement unit 223.

[0206] The transmitting / receiving antenna 230 can be configured from an antenna described based on common understanding in the technical field to which the present disclosure relates, such as an array antenna.

[0207] The transceiver 220 may receive the above-mentioned downlink channel, synchronization signal, downlink reference signal, etc. The transceiver 220 may transmit the above-mentioned uplink channel, uplink reference signal, etc.

[0208] The transceiver unit 220 may form at least one of the transmit beam and the receive beam using digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), or the like.

[0209] The transceiver unit 220 (transmission processing unit 2211) may perform PDCP layer processing, RLC layer processing (e.g., RLC retransmission control), MAC layer processing (e.g., HARQ retransmission control), etc. on data, control information, etc. obtained from the control unit 210, and generate a bit string to be transmitted.

[0210] The transmitter / receiver unit 220 (transmission processing unit 2211) may perform transmission processing such as channel coding (which may include error correction coding), modulation, mapping, filtering, DFT processing (if necessary), IFFT processing, precoding, and digital-to-analog conversion on the bit string to be transmitted, and output a baseband signal.

[0211] Whether or not to apply DFT processing may be based on the setting of transform precoding. When transform precoding is enabled for a certain channel (e.g., PUSCH), the transceiver unit 220 (transmission processing unit 2211) may perform DFT processing as the transmission processing to transmit the channel using a DFT-s-OFDM waveform, and if not, it may not be necessary to perform DFT processing as the transmission processing.

[0212] The transceiver unit 220 (RF unit 222) may perform modulation, filtering, amplification, etc. on the baseband signal to a radio frequency band, and transmit the radio frequency band signal via the transceiver antenna 230.

[0213] On the other hand, the transceiver unit 220 (RF unit 222) may perform amplification, filtering, demodulation to a baseband signal, etc. on the radio frequency band signal received by the transceiver antenna 230.

[0214] The transceiver unit 220 (reception processing unit 2212) may apply reception processing such as analog-to-digital conversion, FFT processing, IDFT processing (if necessary), filtering, demapping, demodulation, decoding (which may include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing to the acquired baseband signal, and acquire user data, etc.

[0215] The transceiver 220 (measurement unit 223) may perform measurements on the received signal. For example, the measurement unit 223 may perform RRM measurements, CSI measurements, etc. based on the received signal. The measurement unit 223 may measure received power (e.g., RSRP), received quality (e.g., RSRQ, SINR, SNR), signal strength (e.g., RSSI), propagation path information (e.g., CSI), etc. The measurement results may be output to the control unit 210.

[0216] The measurement unit 223 may derive channel measurements for CSI calculation based on the channel measurement resources. The channel measurement resources may be, for example, non-zero power (NZP) CSI-RS resources. The measurement unit 223 may also derive interference measurements for CSI calculation based on the interference measurement resources. The interference measurement resources may be at least one of an NZP CSI-RS resource for interference measurement, a CSI-Interference Measurement (IM) resource, etc. Note that CSI-IM may be referred to as CSI-Interference Management (IM) or may be interchangeably read as Zero Power (ZP) CSI-RS. Note that in the present disclosure, CSI-RS, NZP CSI-RS, ZP CSI-RS, CSI-IM, CSI-SSB, etc. may be interchangeably read as interchangeable.

[0217] The transmitting unit and receiving unit of the user terminal 20 in the present disclosure may be configured by at least one of the transmitting / receiving unit 220 and the transmitting / receiving antenna 230.

[0218] The control unit 210 may control the transmission timing of the physical random access channel (PRACH) without receiving a synchronization signal block (SSB).

[0219] The transceiver 220 may transmit the PRACH based on the transmission timing.

[0220] The control unit 210 may control the transmission timing based on whether or not carrier sensing is performed.

[0221] The control unit 210 may control the transmission timing based on specific location information.

[0222] When the control unit 210 is notified of the PRACH resource, the control unit 210 may control the transmission timing based on the resource.

[0223] The control unit 210 may control synchronization for responses (e.g., Msg. 4 HARQ-ACK, Msg. B HARQ-ACK) to at least one of a random access response (RAR) and a specific message indicating contention resolution (e.g., Msg. 4, Msg. B) without receiving a synchronization signal block (SSB).

[0224] The transmitting / receiving unit 220 may transmit the response based on the synchronization.

[0225] The control unit 210 may control the synchronization based on a timing advance (TA).

[0226] The control unit 210 may control the synchronization for each retransmission when at least one of the RAR and the specific message is retransmitted.

[0227] The control unit 210 may apply a preamble signal to the response for synchronizing at least one of time and frequency.

[0228] (Hardware Configuration) Note that the block diagrams used to explain the above embodiments show functional blocks. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method for realizing each functional block is not particularly limited. That is, each functional block may be realized using a single device that is physically or logically coupled, or may be realized using two or more physically or logically separated devices that are directly or indirectly connected (for example, using wires, wirelessly, etc.) and these multiple devices. The functional block may be realized by combining software with the single device or the multiple devices.

[0229] Here, the functions include, but are not limited to, judgment, determination, judgment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, election, establishment, comparison, assumption, expectation, deeming, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assignment. For example, a functional block (component) that performs transmission may be called a transmitting unit, transmitter, etc. As described above, the implementation method of each is not particularly limited.

[0230] For example, a base station, a user terminal, or the like according to an embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Fig. 11 is a diagram illustrating an example of the hardware configuration of a base station and a user terminal according to an embodiment. The above-described base station 10 and user terminal 20 may be physically configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and the like.

[0231] In the present disclosure, the terms apparatus, circuit, device, section, unit, etc. may be used interchangeably. The hardware configurations of the base station 10 and the user terminal 20 may be configured to include one or more of the devices shown in the drawings, or may be configured to exclude some of the devices.

[0232] For example, although only one processor 1001 is shown, there may be multiple processors. Furthermore, processing may be performed by one processor, or processing may be performed by two or more processors simultaneously, serially, or in other ways. Furthermore, processor 1001 may be implemented by one or more chips.

[0233] Each function in the base station 10 and the user terminal 20 is realized, for example, by loading specified software (programs) onto hardware such as a processor 1001 and a memory 1002, causing the processor 1001 to perform calculations, control communication via the communication device 1004, and control at least one of reading and writing data in the memory 1002 and the storage 1003.

[0234] The processor 1001, for example, runs an operating system to control the entire computer. The processor 1001 may be configured as a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic unit, a register, etc. For example, at least a part of the above-mentioned control unit 110 (210), transceiver unit 120 (220), etc. may be realized by the processor 1001.

[0235] The processor 1001 also reads programs (program codes), software modules, data, etc. from at least one of the storage 1003 and the communication device 1004 into the memory 1002 and executes various processes in accordance with these. The programs used are those that cause a computer to execute at least some of the operations described in the above-described embodiments. For example, the control unit 110 (210) may be implemented by a control program stored in the memory 1002 and running on the processor 1001, and the other functional blocks may be implemented in a similar manner.

[0236] The memory 1002 is a computer-readable recording medium and may be configured by at least one of, for example, Read Only Memory (ROM), Erasable Programmable ROM (EPROM), Electrically EEPROM (EEPROM), Random Access Memory (RAM), or other suitable storage medium. The memory 1002 may also be referred to as a register, cache, main memory, etc. The memory 1002 may store executable programs (program codes), software modules, etc. for implementing a wireless communication method according to an embodiment of the present disclosure.

[0237] Storage 1003 is a computer-readable recording medium and may be composed of at least one of, for example, a flexible disk, a floppy disk, a magneto-optical disk (e.g., a compact disc (e.g., a Compact Disc ROM (CD-ROM)), a digital versatile disc, a Blu-ray disc), a removable disk, a hard disk drive, a smart card, a flash memory device (e.g., a card, a stick, a key drive), a magnetic stripe, a database, a server, or other suitable storage medium. Storage 1003 may also be referred to as an auxiliary storage device.

[0238] The communication device 1004 is hardware (transmission / reception device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as, for example, a network device, a network controller, a network card, or a communication module. The communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc. to realize at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, the above-mentioned transmission / reception unit 120 (220), transmission / reception antenna 130 (230), etc. may be realized by the communication device 1004. The transmission / reception unit 120 (220) may be implemented as a transmission unit 120a (220a) and a reception unit 120b (220b) that are physically or logically separated.

[0239] The input device 1005 is an input device (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that accepts input from the outside. The output device 1006 is an output device (e.g., a display, a speaker, a light emitting diode (LED) lamp, etc.) that outputs to the outside. Note that the input device 1005 and the output device 1006 may be integrated into one device (e.g., a touch panel).

[0240] Furthermore, each device, such as the processor 1001 and the memory 1002, is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or may be configured using different buses between each device.

[0241] Furthermore, the base station 10 and the user terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field programmable gate array (FPGA), and some or all of the functional blocks may be realized using this hardware. For example, the processor 1001 may be implemented using at least one of these pieces of hardware.

[0242] In addition, the devices included in the core network 30 (for example, network nodes that provide NF) may also be realized by the above-mentioned functional block / hardware configuration.

[0243] (Modifications) Note that terms described in the present disclosure and terms necessary for understanding the present disclosure may be replaced with terms having the same or similar meanings. For example, a channel, a symbol, and a signal (signal or signaling) may be interchangeable. A signal may also be a message. A reference signal may be abbreviated as RS, and may also be called a pilot, pilot signal, etc. depending on the applicable standard. A component carrier (CC) may also be called a cell, frequency carrier, carrier frequency, etc.

[0244] A radio frame may be composed of one or more periods (frames) in the time domain. Each of the one or more periods (frames) constituting a radio frame may be called a subframe. Furthermore, a subframe may be composed of one or more slots in the time domain. A subframe may have a fixed time length (e.g., 1 ms) that is independent of numerology.

[0245] Here, the numerology may be a communication parameter applied to at least one of transmission and reception of a signal or channel, and may indicate at least one of, for example, Subcarrier Spacing (SCS), bandwidth, symbol length, cyclic prefix length, Transmission Time Interval (TTI), number of symbols per TTI, radio frame structure, specific filtering performed by a transceiver in the frequency domain, and specific windowing performed by a transceiver in the time domain.

[0246] A slot may be composed of one or more symbols (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol or a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol) in the time domain. A slot may also be a time unit based on numerology.

[0247] A slot may include multiple minislots. Each minislot may consist of one or multiple symbols in the time domain. A minislot may also be called a subslot. A minislot may consist of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a minislot may be called PDSCH (PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called PDSCH (PUSCH) mapping type B.

[0248] A radio frame, a subframe, a slot, a minislot, and a symbol all represent time units for transmitting signals. The radio frame, the subframe, the slot, the minislot, and the symbol may be referred to by other names corresponding to the radio frame, the subframe, the slot, the minislot, and the symbol. Note that the time units such as a frame, a subframe, a slot, a minislot, and a symbol in the present disclosure may be interchangeable.

[0249] For example, one subframe may be referred to as a TTI, or multiple consecutive subframes may be referred to as a TTI, or one slot or one minislot may be referred to as a TTI. That is, at least one of the subframe and the TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (for example, 1-13 symbols), or a period longer than 1 ms. Note that the unit representing the TTI may be called a slot, minislot, etc. instead of a subframe.

[0250] Here, TTI refers to, for example, the smallest time unit for scheduling in wireless communication. For example, in an LTE system, a base station performs scheduling to allocate radio resources (such as frequency bandwidth and transmission power that can be used by each user terminal) to each user terminal in TTI units. Note that the definition of TTI is not limited to this.

[0251] The TTI may be a transmission time unit for a channel-encoded data packet (transport block), a code block, a code word, etc., or may be a processing unit for scheduling, link adaptation, etc. When a TTI is given, the time interval (e.g., the number of symbols) to which a transport block, a code block, a code word, etc. is actually mapped may be shorter than the TTI.

[0252] When one slot or one minislot is called a TTI, one or more TTIs (i.e., one or more slots or one or more minislots) may be the minimum time unit for scheduling. Also, the number of slots (minislots) constituting the minimum time unit for scheduling may be controlled.

[0253] A TTI having a time length of 1 ms may be called a regular TTI (TTI in 3GPP Rel. 8-12), normal TTI, long TTI, regular subframe, normal subframe, long subframe, slot, etc. A TTI shorter than a regular TTI may be called a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, minislot, subslot, slot, etc.

[0254] In addition, a long TTI (e.g., a normal TTI, a subframe, etc.) may be interpreted as a TTI having a time length of more than 1 ms, and a short TTI (e.g., a shortened TTI, etc.) may be interpreted as a TTI having a TTI length shorter than the TTI length of a long TTI and greater than or equal to 1 ms.

[0255] A resource block (RB) is a resource allocation unit in the time domain and the frequency domain, and may include one or more consecutive subcarriers in the frequency domain. The number of subcarriers included in an RB may be the same regardless of numerology, for example, 12. The number of subcarriers included in an RB may be determined based on numerology.

[0256] In addition, an RB may include one or more symbols in the time domain and may have a length of one slot, one minislot, one subframe, or one TTI, each of which may be composed of one or more resource blocks.

[0257] In addition, one or more RBs may be referred to as a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, etc.

[0258] Furthermore, a resource block may be composed of one or more resource elements (REs). For example, one RE may be a radio resource region of one subcarrier and one symbol.

[0259] A Bandwidth Part (BWP), which may also be referred to as a partial bandwidth, may represent a subset of contiguous common resource blocks (RBs) for a given numerology on a given carrier, where the common RBs may be identified by their index relative to a Common Reference Point of the carrier. PRBs may be defined in a BWP and numbered within the BWP.

[0260] The BWP may include a UL BWP (BWP for UL) and a DL BWP (BWP for DL). One or more BWPs may be configured for a UE within one carrier.

[0261] At least one of the configured BWPs may be active, and the UE may not expect to transmit or receive a given signal / channel outside the active BWP. Note that the terms "cell," "carrier," etc. in this disclosure may be read as "BWP."

[0262] The above-described structures of radio frames, subframes, slots, minislots, symbols, etc. are merely examples. For example, the number of subframes included in a radio frame, the number of slots per subframe or radio frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in an RB, the number of symbols in a TTI, the symbol length, the cyclic prefix (CP) length, etc. may be changed in various ways.

[0263] Furthermore, the information, parameters, etc. described in the present disclosure may be expressed using absolute values, may be expressed using relative values ​​from a predetermined value, or may be expressed using other corresponding information. For example, a radio resource may be indicated by a predetermined index.

[0264] The names used for parameters and the like in this disclosure are not intended to be limiting in any way. Furthermore, the mathematical expressions and the like using these parameters may differ from those explicitly disclosed in this disclosure. The various channels (PUCCH, PDCCH, etc.) and information elements may be identified by any suitable names, and therefore the various names assigned to these various channels and information elements are not intended to be limiting in any way.

[0265] The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0266] Furthermore, information, signals, etc. may be output from a higher layer to a lower layer and / or from a lower layer to a higher layer. Information, signals, etc. may be input / output via multiple network nodes.

[0267] Input and output information, signals, etc. may be stored in a specific location (for example, memory) or may be managed using a management table. Input and output information, signals, etc. may be overwritten, updated, or added. Output information, signals, etc. may be deleted. Input information, signals, etc. may be transmitted to another device.

[0268] With respect to any information (e.g., variables, constants, parameters) described in the present disclosure, even if not specifically stated in the above embodiments, any first device (e.g., UE / base station) may notify any second device (e.g., base station / UE) of information indicating / specifying (or relating to) the value of the any information.

[0269] The notification of information is not limited to the aspects / embodiments described in the present disclosure, and may be performed using other methods. For example, the notification of information in the present disclosure may be performed by physical layer signaling (e.g., Downlink Control Information (DCI) and Uplink Control Information (UCI)), higher layer signaling (e.g., Radio Resource Control (RRC) signaling, broadcast information (Master Information Block (MIB) and System Information Block (SIB)), Medium Access Control (MAC) signaling), other signals, or a combination thereof.

[0270] Note that the physical layer signaling may be referred to as Layer 1 / Layer 2 (L1 / L2) control information (L1 / L2 control signal), L1 control information (L1 control signal), etc. Furthermore, the RRC signaling may be referred to as an RRC message, such as an RRC Connection Setup message or an RRC Connection Reconfiguration message. Furthermore, the MAC signaling may be notified using, for example, a MAC Control Element (CE).

[0271] Furthermore, notification of specified information (e.g., notification that "it is X") is not limited to explicit notification, but may be made implicitly (e.g., by not notifying the specified information or by notifying other information).

[0272] The determination may be made by a value represented by one bit (0 or 1), by a Boolean value represented by true or false, or by a comparison of numerical values ​​(e.g., comparison with a predetermined value).

[0273] Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0274] Software, instructions, information, etc. may also be transmitted or received over a transmission medium. For example, if software is transmitted from a website, server, or other remote source using wired technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL)), and / or wireless technologies (such as infrared, microwave), these wired and / or wireless technologies are included within the definition of transmission media.

[0275] As used in this disclosure, the terms "system" and "network" may be used interchangeably. A "network" may refer to devices included in the network (e.g., base stations).

[0276] In this disclosure, terms such as "precoding," "precoder," "weight (precoding weight)," "Quasi-Co-Location (QCL)," "Transmission Configuration Indication state (TCI state)," "spatial relation," "spatial domain filter," "transmit power," "phase rotation," "antenna port," "layer," "number of layers," "rank," "resource," "resource set," "beam," "beam width," "beam angle," "antenna," "antenna element," "panel," "UE panel," "transmitting entity," "receiving entity," etc. may be used interchangeably.

[0277] In the present disclosure, the term "antenna port" may be interchangeably read as an antenna port for any signal / channel (e.g., a demodulation reference signal (DMRS) port). In the present disclosure, the term "resource" may be interchangeably read as a resource for any signal / channel (e.g., a reference signal resource, an SRS resource, etc.). The resource may include time / frequency / code / space / power resources. Furthermore, the spatial domain transmission filter may include at least one of a spatial domain transmission filter and a spatial domain reception filter.

[0278] The group may include, for example, at least one of a spatial relationship group, a Code Division Multiplexing (CDM) group, a Reference Signal (RS) group, a Control Resource Set (CORESET) group, a PUCCH group, an antenna port group (e.g., a DMRS port group), a layer group, a resource group, a beam group, an antenna group, a panel group, and the like.

[0279] In addition, in the present disclosure, beam, SRS Resource Indicator (SRI), CORESET, CORESET pool, PDSCH, PUSCH, codeword (CW), transport block (TB), RS, etc. may be read as interchangeable terms.

[0280] In addition, in the present disclosure, the terms TCI state, downlink TCI state (DL TCI state), uplink TCI state (UL TCI state), unified TCI state, common TCI state, joint TCI state, etc. may be read interchangeably.

[0281] Furthermore, in the present disclosure, terms such as "QCL," "QCL assumption," "QCL relationship," "QCL type information," "QCL property / properties," "specific QCL type (e.g., Type A, Type D) property," and "specific QCL type (e.g., Type A, Type D)" may be interchangeable.

[0282] In the present disclosure, terms such as index, identifier (ID), indicator, indication, and resource ID may be interchangeable. In the present disclosure, terms such as sequence, list, set, group, cluster, and subset may be interchangeable.

[0283] Furthermore, the spatial relationship information identifier (ID) (TCI state ID) and the spatial relationship information (TCI state) may be interchangeable. The "spatial relationship information (TCI state)" may be interchangeable with "set of spatial relationship information (TCI state)", "one or more pieces of spatial relationship information", etc. The TCI state and the TCI may be interchangeable. The spatial relationship information and the spatial relationship may be interchangeable.

[0284] In the present disclosure, terms such as "base station (BS)," "radio base station," "fixed station," "NodeB," "eNB (eNodeB)," "gNB (gNodeB)," "access point," "transmission point (TP)," "reception point (RP)," "transmission / reception point (TRP)," "panel," "cell," "sector," "cell group," "carrier," "component carrier," etc. may be used interchangeably. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, picocell, etc.

[0285] A base station can accommodate one or more (e.g., three) cells. When a base station accommodates multiple cells, the overall coverage area of ​​the base station can be partitioned into multiple smaller areas, and each smaller area can be provided with communication service by a base station subsystem (e.g., a small indoor base station (Remote Radio Head (RRH))). The terms "cell" or "sector" refer to part or all of the coverage area of ​​a base station and / or base station subsystem that provides communication service within that coverage.

[0286] In the present disclosure, a base station transmitting information to a terminal may be interpreted as the base station instructing the terminal to control / operate based on the information.

[0287] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0288] A mobile station may also be referred to as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable terminology.

[0289] At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a wireless communication device, etc. Note that at least one of the base station and the mobile station may be a device mounted on a moving object, the moving object itself, etc.

[0290] The mobile body is a movable object that can move at any speed and naturally includes cases where the mobile body is stationary. Examples of the mobile body include, but are not limited to, vehicles, transport vehicles, automobiles, motorcycles, bicycles, connected cars, excavators, bulldozers, wheel loaders, dump trucks, forklifts, trains, buses, handcars, rickshaws, ships and other watercraft, airplanes, rockets, satellites, drones, multicopters, quadcopters, balloons, and objects mounted thereon. The mobile body may also be a mobile body that moves autonomously based on an operation command.

[0291] The mobile object may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile object (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). Note that at least one of the base station and the mobile station may also include devices that do not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an Internet of Things (IoT) device such as a sensor.

[0292] 12 is a diagram showing an example of a vehicle according to an embodiment. The vehicle 40 includes a drive unit 41, a steering unit 42, an accelerator pedal 43, a brake pedal 44, a shift lever 45, left and right front wheels 46, left and right rear wheels 47, axles 48, an electronic control unit 49, various sensors (including a current sensor 50, an RPM sensor 51, an air pressure sensor 52, a vehicle speed sensor 53, an acceleration sensor 54, an accelerator pedal sensor 55, a brake pedal sensor 56, a shift lever sensor 57, and an object detection sensor 58), an information service unit 59, and a communication module 60.

[0293] The drive unit 41 is configured with at least one of an engine, a motor, and a hybrid of an engine and a motor, for example. The steering unit 42 includes at least a steering wheel (also called a handle) and is configured to steer at least one of the front wheels 46 and the rear wheels 47 based on the operation of the steering wheel operated by a user.

[0294] The electronic control unit 49 is composed of a microprocessor 61, memory (ROM, RAM) 62, and a communication port (for example, an input / output (IO) port) 63. Signals are input to the electronic control unit 49 from various sensors 50-58 provided in the vehicle. The electronic control unit 49 may also be called an Electronic Control Unit (ECU).

[0295] The signals from the various sensors 50-58 include a current signal from a current sensor 50 that senses the current of the motor, a rotation speed signal of the front wheels 46 / rear wheels 47 obtained by a rotation speed sensor 51, an air pressure signal of the front wheels 46 / rear wheels 47 obtained by an air pressure sensor 52, a vehicle speed signal obtained by a vehicle speed sensor 53, an acceleration signal obtained by an acceleration sensor 54, a depression amount signal of the accelerator pedal 43 obtained by an accelerator pedal sensor 55, a depression amount signal of the brake pedal 44 obtained by a brake pedal sensor 56, an operation signal of the shift lever 45 obtained by a shift lever sensor 57, and a detection signal for detecting obstacles, vehicles, pedestrians, etc. obtained by an object detection sensor 58.

[0296] The information service unit 59 is composed of various devices, such as a car navigation system, an audio system, speakers, a display, a television, and a radio, for providing (outputting) various information such as driving information, traffic information, and entertainment information, and one or more ECUs for controlling these devices. The information service unit 59 uses information acquired from external devices via the communication module 60 or the like to provide various information / services (e.g., multimedia information / multimedia services) to the occupants of the vehicle 40.

[0297] The information service unit 59 may include input devices (e.g., keyboards, mice, microphones, switches, buttons, sensors, touch panels, etc.) that accept input from the outside, and may also include output devices (e.g., displays, speakers, LED lamps, touch panels, etc.) that output to the outside.

[0298] The driving assistance system unit 64 includes various devices for providing functions to prevent accidents and reduce the driver's driving burden, such as millimeter-wave radar, Light Detection and Ranging (LiDAR), cameras, positioning locators (e.g., Global Navigation Satellite System (GNSS)), map information (e.g., High Definition (HD) maps, Autonomous Vehicle (AV) maps), gyro systems (e.g., Inertial Measurement Units (IMUs), Inertial Navigation Systems (INSs)), artificial intelligence (AI) chips, and AI processors, as well as one or more ECUs that control these devices. The driving assistance system unit 64 also transmits and receives various information via the communication module 60 to realize driving assistance functions or autonomous driving functions.

[0299] The communication module 60 can communicate with the microprocessor 61 and components of the vehicle 40 via the communication port 63. For example, the communication module 60 transmits and receives data (information) via the communication port 63 to and from the drive unit 41, steering unit 42, accelerator pedal 43, brake pedal 44, shift lever 45, left and right front wheels 46, left and right rear wheels 47, axles 48, the microprocessor 61 and memory (ROM, RAM) 62 in the electronic control unit 49, and the various sensors 50-58, which are provided in the vehicle 40.

[0300] The communication module 60 is a communication device that can be controlled by the microprocessor 61 of the electronic control unit 49 and can communicate with an external device. For example, it transmits and receives various information to and from the external device via wireless communication. The communication module 60 may be located either inside or outside the electronic control unit 49. The external device may be, for example, the base station 10 or the user terminal 20 described above. Furthermore, the communication module 60 may be, for example, at least one of the base station 10 and the user terminal 20 described above (or may function as at least one of the base station 10 and the user terminal 20).

[0301] The communication module 60 may transmit at least one of signals from the above-mentioned various sensors 50-58 input to the electronic control unit 49, information obtained based on the signals, and information based on input from the outside (user) obtained via the information service unit 59 to an external device via wireless communication. The electronic control unit 49, the various sensors 50-58, the information service unit 59, etc. may be referred to as input units that accept input. For example, the PUSCH transmitted by the communication module 60 may include information based on the above-mentioned input.

[0302] The communication module 60 receives various information (traffic information, traffic signal information, vehicle distance information, etc.) transmitted from an external device and displays it on an information service unit 59 provided in the vehicle. The information service unit 59 may also be called an output unit that outputs information (for example, outputs information to a device such as a display or speaker based on the PDSCH received by the communication module 60 (or data / information decoded from the PDSCH)).

[0303] Furthermore, the communication module 60 stores various information received from external devices in a memory 62 that can be used by the microprocessor 61. Based on the information stored in the memory 62, the microprocessor 61 may control the drive unit 41, steering unit 42, accelerator pedal 43, brake pedal 44, shift lever 45, left and right front wheels 46, left and right rear wheels 47, axles 48, various sensors 50-58, and the like provided in the vehicle 40.

[0304] Furthermore, a base station in the present disclosure may be read as a user terminal. For example, the aspects / embodiments of the present disclosure may be applied to a configuration in which communication between a base station and a user terminal is replaced with communication between multiple user terminals (which may be called, for example, Device-to-Device (D2D) or Vehicle-to-Everything (V2X)). In this case, the user terminal 20 may be configured to have the functions of the base station 10 described above. Furthermore, terms such as "uplink" and "downlink" may be read as terms corresponding to terminal-to-terminal communication (for example, "sidelink"). For example, terms such as an uplink channel and a downlink channel may be read as a sidelink channel.

[0305] Similarly, the user terminal in the present disclosure may be read as a base station, in which case the base station 10 may be configured to have the functions of the user terminal 20 described above.

[0306] In the present disclosure, an operation described as being performed by a base station may be performed by its upper node in some cases. It is apparent that in a network including one or more network nodes having a base station, various operations performed for communication with a terminal may be performed by the base station, one or more network nodes other than the base station (such as, but not limited to, a Mobility Management Entity (MME), a Serving-Gateway (S-GW), etc.), or a combination thereof.

[0307] Each aspect / embodiment described in this disclosure may be used alone, in combination, or switched depending on the implementation. Furthermore, the order of the processing procedures, sequences, flowcharts, etc. of each aspect / embodiment described in this disclosure may be changed unless inconsistent. For example, the methods described in this disclosure present elements of various steps using an example order, and are not limited to the particular order presented.

[0308] Each aspect / embodiment described in the present disclosure may be a technology other than Long Term Evolution (LTE), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), 6th generation mobile communication system (6G), xth generation mobile communication system (xG (x is, for example, an integer or decimal number)), Future Radio Access (FRA), New-Radio Access Technology (RAT), New Radio (NR), New radio access (NX), Future generation radio access (FX), Global System for Mobile communications (GSM (registered trademark)), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.17 (WiMAX (registered trademark)), IEEE 802.19 (WiMAX (registered trademark)), IEEE 802.20 (WiMAX (registered trademark)), IEEE 802.21 (Wi-Fi (registered trademark)), IEEE 802.22 (WiMAX (registered trademark)), IEEE 802.23 (WiMAX (registered trademark)), IEEE 802.24 (WiMAX (registered trademark)), IEEE 802.25 (WiMAX (registered trademark)), IEEE 802.26 (WiMAX (registered trademark)), IEEE 802.27 (WiMAX (registered trademark)), IEEE 802.28 (WiMAX (registered trademark)), IEEE 802.29 (WiMAX (registered trademark)), IEEE 802.30 (WiMAX (registered trademark)), IEEE 802.31 (Wi-Fi (registered trademark)), IEEE 802.32 (WiMAX (registered trademark)), IEEE 802.33 (WiMAX (registered trademark)), IEEE 802. The present invention may be applied to systems that use IEEE 802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), or other suitable wireless communication methods, or to next-generation systems that are expanded, modified, created, or defined based on these. Furthermore, the present invention may be applied to a combination of multiple systems (e.g., a combination of LTE or LTE-A and 5G).

[0309] As used in this disclosure, the phrase "based on" does not mean "based only on," unless expressly stated otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

[0310] As used in this disclosure, any reference to an element using a designation such as "first," "second," etc. does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements. Thus, a reference to a first and a second element does not imply that only two elements may be employed or that the first element must in some way precede the second element.

[0311] The term "determining" as used in this disclosure may encompass a wide variety of actions. For example, "determining" may be considered to be judging, calculating, computing, processing, deriving, investigating, looking up, search, inquiry (e.g., looking up in a table, database, or another data structure), ascertaining, etc.

[0312] Additionally, "determining" may be considered to be "determining" receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in memory), etc.

[0313] Furthermore, "determination" may be considered to be "determining" resolving, selecting, choosing, establishing, comparing, etc. In other words, "determination" may be considered to be "determining" some kind of action. In the present disclosure, "determination" may be read interchangeably with the above-mentioned actions.

[0314] Furthermore, in this disclosure, "determine / determining" may be interchangeably read as "assume / assuming," "expect / expecting," "consider / considering," etc. Furthermore, in this disclosure, "does not expect to do..." may be interchangeably read as "assumes not to do...."

[0315] In the present disclosure, "expect" may be interchangeably read as "be expected." For example, "expect(s) ..." ("..." may be expressed, for example, as a that clause, a to-infinitive, etc.) may be interchangeably read as "be expected ..." or "do ... (if the above "..." is a to-infinitive, a verb with "to")," etc. "does not expect ..." may be interchangeably read as "be not expected ..." or "does not ... (if the above "..." is a to-infinitive, a verb with "to")," etc. Furthermore, "An apparatus A is not expected ..." may be interchangeably read as "an apparatus B other than apparatus A does not expect ... from apparatus A" (for example, if apparatus A is a UE, apparatus B may be a base station).

[0316] The "maximum transmit power" in this disclosure may mean the maximum value of transmit power, the nominal UE maximum transmit power, or the rated UE maximum transmit power.

[0317] As used in this disclosure, the terms "connected," "coupled," or any variation thereof, refer to any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, "connected" may be read as "access."

[0318] In this disclosure, when two elements are connected, they may be considered to be "connected" or "coupled" to one another using one or more wires, cables, printed electrical connections, etc., as well as using electromagnetic energy having wavelengths in the radio frequency range, microwave range, light (both visible and invisible) range, etc., as some non-limiting and non-exhaustive examples.

[0319] In the present disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "coupled" may also be interpreted in the same way as "different."

[0320] When the terms "include," "including," and variations thereof are used in this disclosure, these terms are intended to be inclusive, similar to the term "comprising." Furthermore, when the term "or" is used in this disclosure, it is not intended to be an exclusive or.

[0321] In this disclosure, where articles are added by translation, such as a, an, and the in English, the disclosure may include that the nouns following these articles are in the plural form.

[0322] In the present disclosure, terms such as "less than or equal to," "less than," "greater than," "more than," "equal to," etc. may be interchangeable. Furthermore, in the present disclosure, terms meaning "good," "bad," "big," "small," "high," "low," "fast," "slow," "wide," "narrow," etc. may be interchangeable, not limited to the positive, comparative, and superlative. Furthermore, in the present disclosure, terms meaning "good," "bad," "big," "small," "high," "low," "fast," "slow," "wide," "narrow," etc. may be interchangeable, not limited to the positive, comparative, and superlative, as expressions with "i-th" (i is an arbitrary integer) attached (for example, "highest" may be interchangeable with "i-th highest").

[0323] In this disclosure, the terms "of," "for," "regarding," "related to," "associated with," etc. may be read interchangeably.

[0324] In the present disclosure, terms such as "when A, B," "if A, (then) B," "B upon A," "B in response to A," "B based on A," "B during / while A," "B before A," "B at (the same time as) / on A," "B after A," "B since A," and "B until A" may be interchangeable. Note that A, B, and the like herein may be replaced with appropriate expressions such as nouns, gerunds, and regular sentences, depending on the context. Note that the time difference between A and B may be approximately zero (immediately after or immediately before). A time offset may also be applied to the time at which A occurs. For example, "A" may be interchangeable with "before / after a time offset at which A occurs." The time offset (eg, one or more symbols / slots) may be predefined or may be specified by the UE based on signaled information.

[0325] In the present disclosure, timing, time, duration, time instance, any time unit (e.g., slot, subslot, symbol, subframe), period, occasion, resource, etc. may be read interchangeably.

[0326] Although the invention according to the present disclosure has been described in detail above, it is clear to those skilled in the art that the invention according to the present disclosure is not limited to the embodiments described in the present disclosure. The description of the present disclosure is for illustrative purposes only and does not impose any limiting meaning on the invention according to the present disclosure.

Claims

1. A terminal having a control unit that controls the transmission timing of a physical random access channel (PRACH) without receiving a synchronization signal block (SSB), and a transmission unit that transmits the PRACH based on the transmission timing.

2. The terminal according to claim 1, wherein the control unit controls the transmission timing based on whether or not carrier sensing is performed.

3. The terminal according to claim 1, wherein the control unit controls the transmission timing based on specific location information.

4. The terminal according to claim 1, wherein, when a resource for the PRACH is notified, the control unit controls the transmission timing based on the resource.

5. A wireless communication method for a terminal, comprising: a step of controlling the transmission timing of a physical random access channel (PRACH) without receiving a synchronization signal block (SSB); and a step of controlling the PRACH based on the transmission timing.

6. A base station having: a control unit that controls the transmission timing of a physical random access channel (PRACH) of a terminal without transmitting a synchronization signal block (SSB); and a receiving unit that receives the PRACH transmitted based on the transmission timing.

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