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 determines, on the basis of information pertaining to reception timing of a downlink (DL) signal for an initial access, a specific reception timing of the DL signal without receiving a synchronization signal block (SSB); and a reception unit that receives the DL signal on the basis of the specific reception timing. According to one aspect of the present disclosure, the initial access can be appropriately performed even in a case in which a UE and a base station are not synchronized with each other.

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

[0006] However, because existing systems are designed on the assumption that UEs and base stations are time-synchronized, the initial access procedure for asynchronous communication has not been adequately considered. In this case, the initial access procedure may not be performed properly, which may result in a decrease in system performance, such as a decrease in communication throughput.

[0007] Therefore, one of the objectives of the present disclosure is to provide a terminal, a wireless communication method, and a base station that can properly perform initial access even when the UE and the base station are not synchronized.

[0008] A terminal according to one aspect of the present disclosure is characterized in that it has a control unit that determines a specific reception timing of a downlink (DL) signal for initial access based on information regarding the reception timing of the DL signal without receiving a synchronization signal block (SSB), and a receiving unit that receives the DL signal based on the specific reception timing.

[0009] According to one aspect of the present disclosure, initial access can be performed appropriately even when the UE and the base station are not synchronized.

[0010] FIG. 1 is a diagram showing an example of a four-step RA. FIG. 2 is a diagram showing an example of a two-step RA. FIGS. 3A and 3B are diagrams showing an example of initial access. FIG. 4 is a diagram showing an example of symbol boundary synchronization. FIG. 5 is a diagram showing an example of system synchronization. FIG. 6 is a diagram showing an example of a schematic configuration of a wireless communication system according to an embodiment. FIG. 7 is a diagram showing an example of a base station configuration according to an embodiment. FIG. 8 is a diagram showing an example of a user terminal configuration according to an embodiment. FIG. 9 is a diagram showing an example of hardware configurations of a base station and a user terminal according to an embodiment. FIG. 10 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 UE transmits a preamble randomly selected from multiple 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 UE-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 UE specifically via a downlink (DL) control channel (Physical Downlink Control Channel (PDCCH)), and the UE 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, at the start or restart of DL transmission (at the start or restart of UL transmission of DL retransmission instruction information), etc.

[0034] Fig. 1 is a diagram illustrating an example of contention-based random access. In Fig. 1, a UE receives information (PRACH configuration information) indicating a configuration of a random access channel (PRACH) (PRACH configuration, RACH configuration) in advance 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 the UE transitions from an idle (RRC_IDLE) state to an RRC connected (RRC_CONNECTED) state (e.g., at the time of initial access), when the UE is in an RRC connected state but UL synchronization is not established (e.g., at the start or restart of UL transmission), etc., the UE 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 UE 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 the preamble. Increasing the transmission power during retransmission is also called power ramping.

[0038] Upon receiving the RAR, the UE adjusts its UL transmission timing based on the timing advance (TA) included in the RAR to establish UL synchronization. The UE also transmits a control message (Message 3, Msg. 3) of the upper layer (L2 / L3: Layer 2 / Layer 3) using the UL resource specified by the UL grant included in the RAR. The control message includes the UE's identifier (UE-ID). The UE's identifier may be, for example, a Cell-Radio Network Temporary Identifier (C-RNTI) if the UE 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 UE 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 UE identifier included in the control message. A UE that successfully detects the collision resolution message transmits an acknowledgement (ACK) in Hybrid Automatic Repeat reQuest (HARQ) to the radio base station. As a result, the UE in idle state transitions to an RRC connected state.

[0040] On the other hand, a UE 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 UE, it transmits an UL grant to the UE. The UE transmits UL data using the UL resources allocated by the UL grant.

[0041] In the above-described contention-based random access, a UE 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 UE 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 UE may transmit an ACK / NACK in response to Msg. B. This ACK / NACK may 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, or the like.

[0048] (Analysis) Existing systems (e.g., NR) are designed on the premise of time synchronization (e.g., symbol boundary synchronization, system synchronization) between a UE and a base station. In the existing system, a procedure for time 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 resources of the UE and the base station.

[0049] Symbol boundary synchronization is primarily performed to ensure UE reception performance, while system synchronization is primarily performed for time-related control (e.g., signal transmission timing, Time Division Duplex (TDD), beamforming).

[0050] Discussions on future wireless communication systems (for example, Beyond 5G and 6G) ​​have begun. One of the issues being considered for Beyond 5G and 6G is how to improve communication efficiency.

[0051] 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 system (initial access procedure of asynchronous communication). Asynchronous communication is expected to reduce overhead due to synchronization and maximize communication efficiency.

[0052] However, as mentioned above, existing systems are designed on the assumption that UEs and base stations are time-synchronized, and therefore initial access procedures for asynchronous communication have not been fully considered. In such cases, the initial access procedure may not be performed properly, which may result in degradation of system performance, such as a decrease in communication throughput.

[0053] Therefore, the present inventors have conceived the following embodiment: According to one aspect of the present disclosure, initial access can be properly performed even in a case where a UE and a base station are not synchronized.

[0054] 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.

[0055] (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.

[0056] 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."

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] In the present disclosure, physical layer signaling may be, for example, Downlink Control Information (DCI), Uplink Control Information (UCI), and the like.

[0062] In the present disclosure, the terms drop, abort, cancel, puncture, rate match, postpone, do not transmit, etc. may be read interchangeably.

[0063] In the present disclosure, the terms carrier, band, cell, band, frequency [resource], etc. may be read interchangeably.

[0064] In the present disclosure, the terms radio frame, frame, subframe, slot, symbol, time [resource], timing, etc. may be read interchangeably.

[0065] 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.

[0066] 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.

[0067] In the present disclosure, Msg. 1, PRACH, random access preamble, preamble, Msg. A, first message, first signal, [UL] signal, etc. may be read interchangeably.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] In the present disclosure, the terms ID, index, identifier, etc. may be read interchangeably.

[0073] In the present disclosure, the random access preamble ID, RAPID, RACH ID, etc. may be read interchangeably.

[0074] 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.

[0075] In the present disclosure, a signal / channel may be interpreted as a UL signal / channel, a DL signal / channel, etc. A UL signal / channel may be interpreted as a PUCCH, a PUSCH, a PRACH, an SRS, an uplink (UL) demodulation reference signal (DMRS), etc. A DL signal / channel may be interpreted as a PDCCH, a PDSCH, an SSB, a downlink (DL) DMRS, etc.

[0076] In the present disclosure, the terms symbol [boundary / position], slot [boundary / position], subframe [boundary / position], frame [boundary / position], second [boundary / position], millisecond [boundary / position], time unit [boundary / position], timing, time, time resource, etc. may be interpreted interchangeably.

[0077] (Wireless Communication Method) In the following embodiments, a symbol may mean a time unit in an existing system or a time unit in a future wireless communication system.

[0078] The UE may perform initial access according to at least one of the following conditions 1 to 4: Condition 1: Both symbol boundary synchronization and system synchronization are performed. Condition 2: Symbol boundary synchronization is performed, but system synchronization is not performed. Condition 3: Symbol boundary synchronization is not performed, but system synchronization is performed. Condition 4: Both symbol boundary synchronization and system synchronization are not performed.

[0079] The initial access according to condition 1 may be called an initial access that performs time synchronization (or that involves time synchronization). The initial access according to condition 2 / condition 3 / condition 4 may be called an initial access that does not perform time synchronization (or that does not involve time synchronization), or an initial access that is performed without receiving SSB (not based on SSB) (or an initial access that does not involve [synchronization by] SSB).

[0080] In the initial access with time synchronization, the base station may transmit an SSB to the UE, and the UE may receive the SSB (FIG. 3A). In this case, time synchronization between the UE and the base station may be achieved based on the SSB.

[0081] In the initial access without time synchronization, the base station does not need to transmit the SSB to the UE, and the UE does not need to receive the SSB (FIG. 3B). In this case, time synchronization between the UE and the base station based on the SSB is not required.

[0082] In this disclosure, symbol boundary synchronization (symbol boundaries are synchronized) may mean that the symbol boundaries of the UE and the base station coincide.

[0083] 4 illustrates an example of symbol boundary synchronization. When a base station transmits a signal to a UE, a propagation delay (which may vary from UE to UE) may occur. The propagation delay may also cause a gap in the recognition of symbol boundaries between the UE and the base station. Symbol boundary synchronization may compensate / correct for this gap. Symbol boundary synchronization may ensure that the symbol boundaries between the UE and the base station are aligned.

[0084] In the present disclosure, system synchronization may mean that the UE and the base station have a common understanding of time (e.g., transmission timing / reception timing of signals / channels).

[0085] Fig. 5 is a diagram illustrating an example of system synchronization. In Fig. 5, a UE and a base station may recognize specific time resources (time resources indicated by diagonal lines) as having the same timing. The specific time resources may completely overlap or partially overlap between the UE and the base station.

[0086] The UE may receive information / settings for system synchronization (e.g., information / settings related to a system frame number (SFN)). The UE may also perform a process / operation for system synchronization based on the information / settings. This process / operation may be preferably applied, for example, when an initial access conforming to condition 3 is performed.

[0087] 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.).

[0088] First Embodiment The first embodiment relates to initial access.

[0089] The UE / base station may perform an initial access procedure based on at least one of the following embodiments 1.1 to 1.3. Note that the following embodiments 1.1 to 1.3 are preferably applicable to initial access without time synchronization, but may also be applicable to initial access with time synchronization.

[0090] <<Embodiment 1.1>> Embodiment 1.1 is preferably applicable when initial access is performed in accordance with condition 2, but may also be applied to initial access in accordance with other conditions (e.g., condition 1 / condition 3 / condition 4).

[0091] The UE may receive information about the system frame number (SFN) of the received signal / channel, which may be signaled by SIB / RRC or from another RAT / base station / cell.

[0092] The UE may receive a notification regarding the timing of reception / transmission of a signal / channel. The UE may determine / judge the timing of reception / transmission of a signal / channel based on the notification. The UE may receive / transmit the signal / channel at the timing.

[0093] The notification regarding the timing of reception / transmission of signals / channels may follow at least one of the following methods A1 and A2.

[0094] Method A1: A relative value of the timing of reception / transmission of a signal / channel based on the timing of receiving the notification may be predefined. For example, the timing of reception / transmission of the signal / channel may be predefined as X time units (e.g., X symbols / slots / subframes / frames / seconds / milliseconds) after the timing of receiving the notification (e.g., 0).

[0095] Method A2: A relative value of the reception / transmission timing of a signal / channel based on the timing at which the notification is received may be notified / instructed to the UE. For example, the UE may be notified / instructed to receive / transmit a signal / channel at a timing Y time units (e.g., Y symbols / slots / subframes / frames / seconds / milliseconds) after the timing at which the notification is received (e.g., 0). The relative value Y may be notified / instructed by the notification, may be notified / instructed by SIB / RRC, or may be notified / instructed by another RAT / base station / cell.

[0096] The relative values ​​of the methods A1 / A2 may be constant (fixed values), which can simplify the processing / operations related to determining / judging the timing of receiving / transmitting signals / channels.

[0097] The relative value of the method A1 / A2 may be variable. For example, whether the first relative value or the second relative value is used may be determined based on a condition regarding time resources. In this case, the timing of receiving / transmitting signals / channels can be flexibly controlled.

[0098] According to the embodiment 1.1 described above, it is possible to omit sending and receiving information related to system synchronization, thereby reducing overhead in initial access.

[0099] <<Embodiment 1.2>> Embodiment 1.2 is preferably applicable when initial access is performed in accordance with condition 3, but may also be applied to initial access in accordance with other conditions (for example, condition 1 / condition 2 / condition 4).

[0100] When a signal / channel is received, information regarding the SFN of that signal / channel may be notified to the UE.

[0101] For system synchronization, coarse synchronization of symbol boundaries may be performed. The UE may determine timing for transmitting / receiving signals / channels based on the coarse synchronization of symbol boundaries. The UE may transmit / receive signals / channels at the timing. The coarse synchronization of symbol boundaries may be performed according to at least one of the following methods B1 to B3.

[0102] Method B1: Synchronization signals (e.g., SSB) may not be configured / received / transmitted. The UE may receive / transmit signals / channels other than synchronization signals (e.g., DL signals / channels, UL signals / channels). Based on these signals / channels, coarse synchronization of symbol boundaries may be performed.

[0103] Method B2: The UE may change the synchronization accuracy / reception accuracy of a specific signal / channel. For example, the UE may change the block error rate (BLER) applied to reception of a specific signal / channel. As an example, the UE may control to receive the PDCCH at a BLER of Z%. The value of Z may be defined in the specifications or may be notified / configured to the UE by the base station. Based on the synchronization accuracy / reception accuracy, coarse synchronization of the symbol boundary may be performed.

[0104] Method B3: Coarse synchronization of symbol boundaries may be performed based on at least one of other systems (e.g., specific position information such as GNSS) and specific time information (e.g., an internal clock).

[0105] For reception characteristics, a preamble may be applied / added to the transmitted signal / channel.

[0106] According to the above-described embodiment 1.2, it is possible to omit sending and receiving information relating to synchronization of symbol boundaries, thereby reducing overhead in initial access.

[0107] <<Embodiment 1.3>> Embodiment 1.3 is preferably applicable when initial access is performed in accordance with condition 4, but may also be applied to initial access in accordance with other conditions (for example, condition 1 / condition 2 / condition 3).

[0108] The transmitting UE / base station may transmit a signal / channel at any timing, and the receiving UE / base station may monitor (blind decode) the signal / channel.

[0109] For example, in condition 4, there is no set time for transmission / reception, so the transmitting UE / base station may transmit a signal / channel at any timing. In this case, the receiving UE / base station may perform reception control so as to constantly monitor the signal.

[0110] The transmission / reception of signals / channels may be performed according to at least one of the following methods C1 and C2.

[0111] Method C1: A transmitting UE / base station may transmit a specific control signal (UL signal / DL signal) before transmitting a signal / channel. A receiving UE / base station may receive the specific control signal. The specific control signal may indicate at least one of a transmission timing, a reception timing, and a transmission method of the signal / channel. The specific control signal (first signal) may also trigger the receiving UE / base station to transmit a signal (second signal).

[0112] Method C1 may further follow at least one of the following methods C1-1 and C1-2.

[0113] Method C1-1: Subsequent control information (at initial access) may be notified based on the transmission timing / reception timing of a specific control signal.

[0114] Method C1-2: Before transmitting / receiving a signal / channel, a procedure equivalent to initial access (e.g., transmitting / receiving SSB / Msg.1 / Msg.2 / Msg.3 / Msg.4 / Msg.A / Msg.B) may be performed.

[0115] Method C2: The transmitting UE / base station may transmit a periodic signal in the UL / DL, and the receiving UE / base station may determine / judge at least one of the transmission timing, reception timing, and transmission method of the signal / channel based on the periodic signal.

[0116] Methods C1 / C2 can reduce the monitoring load on the receiving UE / base station.

[0117] Frequency Division Duplex (FDD) may be applied to UL and DL transmissions, which simplifies signal / channel transmission and reception processing since the receiving UE / base station does not need to perform full-duplex operation (e.g., simultaneous UL transmission and DL reception).

[0118] According to the above-described embodiment 1.3, it is possible to omit sending and receiving information relating to symbol boundary synchronization and information relating to system synchronization, thereby reducing overhead in initial access.

[0119] In a system where DL is asynchronous (for example, a system that supports initial access according to condition 2 / condition 3 / condition 4), initial access may follow at least one of the following methods D1 to D3.

[0120] Method D1: Information on a transmission signal (e.g., PRACH) may be notified from the base station to the UE by a specific DL signal (e.g., PDCCH, SIB1 PDSCH). Note that the transmission signal may be interpreted as an UL signal or the like.

[0121] Method D1 may further follow at least one of the following methods D1-1 and D1-2.

[0122] Method D1-1: The absolute time at which a signal (e.g., a transmission signal, a specific DL signal) is transmitted may be specified by a specification. The UE may derive / calculate the absolute time based on at least one of specific location information (e.g., GNSS) and specific time information (e.g., an internal clock).

[0123] Method D1-2: The information may be notified using another communication system (e.g., 4G / 5G).

[0124] Method D2: A transmission signal may be sent from the UE to the base station.

[0125] Method D2 may further follow at least one of the following methods D2-1 to D2-4.

[0126] Method D2-1: The transmission timing of the transmission signal may be determined based on the information of Method D1.

[0127] Method D2-2: The UE may transmit a transmission signal at any timing, and the base station may monitor the transmission signal.

[0128] Method D2-3: The absolute time at which the transmission signal is transmitted may be specified by a specification. The UE may derive / calculate the absolute time based on at least one of specific location information (e.g., GNSS) and specific time information (e.g., an internal clock).

[0129] Method D2-4: The information may be notified using another communication system (e.g., 4G / 5G).

[0130] Method D3: A reply signal / response signal to the transmission signal may be transmitted from the base station to the UE. Note that the reply signal / response signal may be interpreted as a DL signal or the like.

[0131] In method D3, the UE may monitor a reply signal / response signal transmitted from the base station for a specific period. For example, the specific period may be a period until K time units (e.g., K symbols / slots / subframes / frames / seconds / milliseconds) have elapsed since the transmission of the transmission signal in method D2. Information regarding the specific period (e.g., the value of K) may be notified by the information transmitted in method D1, or may be notified / instructed by SIB / RRC, or may be notified / instructed by another RAT / base station / cell. Alternatively, the specific period may be predefined by a specification.

[0132] According to the first embodiment described above, initial access can be performed appropriately even without time synchronization (for example, synchronization of symbol boundaries, synchronization of systems).

[0133] Second Embodiment The second embodiment relates to maintaining time synchronization.

[0134] The UE may maintain time synchronization without using (receiving) synchronization signals / SSB.

[0135] The UE may maintain / keep information about the time of transmission / reception of previously transmitted / received signals / channels, in which case the UE may follow at least one of the following methods E1 to E3:

[0136] Method E1: When a UE transmits / receives a signal / channel, the UE may maintain / keep information about the time of transmission / reception of the signal / channel (information about [time] synchronization). When the UE transmits / receives (monitors) the next signal / channel, the UE may transmit / receive (monitors) the next signal / channel based on the information.

[0137] Method E2: The UE may use an external signal (e.g., specific location information such as GNSS) to maintain / save information about the time of transmission / reception of signals / channels (information about [time] synchronization). A period for maintaining / storing information about the time of transmission / reception of signals / channels (information about [time] synchronization) may be set. When the period elapses / expires, the information about the time of transmission / reception of signals / channels (information about [time] synchronization) may be discarded.

[0138] Method E3: The UE may use cell-specific / UE-specific signaling to maintain / retain information about the time of transmission / reception of signals / channels (time synchronization information). For example, the UE may monitor a specific DL signal / channel (e.g., PDCCH) to maintain / retain information about the time of transmission / reception of signals / channels (time synchronization information).

[0139] According to the second embodiment described above, it is possible to omit reception of a synchronization signal / SSB for maintaining time synchronization, thereby reducing communication overhead.

[0140] <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.

[0141] 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.

[0142] 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.

[0143] Furthermore, notification of any information to the UE in the above embodiments may be performed periodically, semi-persistently, or aperiodically.

[0144] <<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.

[0145] 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.

[0146] If the notification is made by UCI, the notification may be transmitted using PUCCH or PUSCH.

[0147] Furthermore, any information in the above-described embodiments may be notified from the UE periodically, semi-persistently, or aperiodically.

[0148] <<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.

[0149] The specific UE capability may indicate at least one of the following: - Support for the specific process / operation / control / assumption / information; - Support for asynchronous communication (e.g. initial access according to condition 2 / condition 3 / condition 4); - Information regarding the synchronization accuracy of the UE.

[0150] 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).

[0151] 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)).

[0152] If the above conditions are not met, the UE / BS may follow the behavior specified in existing 3GPP releases.

[0153] (Supplementary Notes) The following inventions are supplementary notes regarding one embodiment of the present disclosure. [Supplementary Note 1] A terminal having: a control unit that determines a specific reception timing of a downlink (DL) signal for initial access based on information regarding the reception timing of the DL signal without receiving a synchronization signal block (SSB); and a receiving unit that receives the DL signal based on the specific reception timing. [Supplementary Note 2] The terminal according to Supplementary Note 1, wherein the control unit determines the specific reception timing based on the timing of receiving the information and a relative value notified by the information. [Supplementary Note 3] The terminal according to Supplementary Note 1 or Supplementary Note 2, wherein the control unit changes the reception accuracy of the specific signal and determines the specific reception timing based on the reception accuracy. [Supplementary Note 4] The terminal according to any one of Supplementary Notes 1 to 3, wherein the control unit maintains information regarding the time of reception of the DL signal.

[0154] (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.

[0155] 6 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).

[0156] 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.

[0157] 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.

[0158] 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))).

[0159] 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.

[0160] 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.

[0161] 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).

[0162] 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.

[0163] 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.

[0164] 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.

[0165] 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.

[0166] 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.

[0167] The user terminal 20 may be a terminal that supports at least one of communication methods such as LTE, LTE-A, and 5G.

[0168] 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).

[0169] 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.

[0170] 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.

[0171] 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.

[0172] 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).

[0173] 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.

[0174] 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.

[0175] 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.

[0176] 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.

[0177] 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.

[0178] 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.

[0179] 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.

[0180] 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.

[0181] 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).

[0182] 7 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.

[0183] 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.

[0184] 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.

[0185] 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.

[0186] 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.

[0187] 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.

[0188] 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.

[0189] 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.

[0190] 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.

[0191] 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.

[0192] 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.

[0193] 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.

[0194] On the other hand, the transceiver unit 120 (RF unit 122) may perform amplification, filtering, demodulation to a baseband signal, etc. on the radio frequency band signal received by the transceiver antenna 130.

[0195] 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.

[0196] 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.

[0197] 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.

[0198] 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.

[0199] 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.

[0200] 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.

[0201] The control unit 110 may use information regarding the timing of receiving a downlink (DL) signal for initial access to instruct a specific timing of receiving the DL signal without transmitting a synchronization signal block (SSB).

[0202] The transceiver 120 may transmit the DL signal that is received based on the specific reception timing.

[0203] (User Terminal) Fig. 8 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 may include one or more of each of the control unit 210, the transceiver unit 220, and the transceiver antenna 230.

[0204] 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.

[0205] 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.

[0206] 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.

[0207] 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.

[0208] 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.

[0209] 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.

[0210] 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.

[0211] 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.

[0212] 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.

[0213] 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.

[0214] 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.

[0215] 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.

[0216] 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.

[0217] 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.

[0218] 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.

[0219] 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.

[0220] 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.

[0221] The control unit 210 may determine the specific reception timing of the downlink (DL) signal for initial access based on information regarding the reception timing of the DL signal without receiving a synchronization signal block (SSB) (first embodiment).

[0222] The transceiver 220 may receive the DL signal based on the specific reception timing (first embodiment).

[0223] The control unit 210 may determine the specific reception timing based on the timing at which the information is received and the relative value notified by the information (first embodiment).

[0224] The control unit 210 may change the reception accuracy of a specific signal and determine the specific reception timing based on the reception accuracy (first embodiment).

[0225] The control unit 210 may maintain information regarding the time of reception of the DL signal (second embodiment).

[0226] (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.

[0227] 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.

[0228] For example, a base station, a user terminal, etc. 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. 9 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, etc.

[0229] 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.

[0230] 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.

[0231] 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.

[0232] 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.

[0233] 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.

[0234] 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.

[0235] 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.

[0236] 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.

[0237] 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).

[0238] 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.

[0239] 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.

[0240] 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.

[0241] (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.

[0242] 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.

[0243] 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.

[0244] 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.

[0245] 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.

[0246] 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.

[0247] 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.

[0248] 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.

[0249] 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.

[0250] 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.

[0251] 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.

[0252] 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.

[0253] 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.

[0254] 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.

[0255] 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.

[0256] 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.

[0257] 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.

[0258] 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.

[0259] 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."

[0260] 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.

[0261] 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.

[0262] 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.

[0263] 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.

[0264] 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.

[0265] 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.

[0266] 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.

[0267] 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.

[0268] 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).

[0269] 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).

[0270] 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).

[0271] 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.

[0272] 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.

[0273] 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).

[0274] 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.

[0275] 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.

[0276] 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.

[0277] 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.

[0278] 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.

[0279] 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.

[0280] 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.

[0281] 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.

[0282] 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.

[0283] 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.

[0284] 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.

[0285] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0286] 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.

[0287] 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.

[0288] 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.

[0289] 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.

[0290] 10 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.

[0291] 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.

[0292] 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).

[0293] 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.

[0294] 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.

[0295] 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.

[0296] 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.

[0297] 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.

[0298] 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).

[0299] 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.

[0300] 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)).

[0301] 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.

[0302] 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.

[0303] 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.

[0304] 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.

[0305] 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.

[0306] 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).

[0307] 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."

[0308] 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.

[0309] 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.

[0310] 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.

[0311] 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.

[0312] 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...."

[0313] 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).

[0314] 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.

[0315] 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."

[0316] 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.

[0317] 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."

[0318] 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.

[0319] 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.

[0320] 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").

[0321] In this disclosure, the terms "of," "for," "regarding," "related to," "associated with," etc. may be read interchangeably.

[0322] 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.

[0323] 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.

[0324] 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 determines a specific reception timing of a downlink (DL) signal for initial access based on information regarding the reception timing of the DL signal without receiving a synchronization signal block (SSB), and a receiving unit that receives the DL signal based on the specific reception timing.

2. The terminal according to claim 1, wherein the control unit determines the specific reception timing based on the timing at which the information is received and a relative value notified by the information.

3. The terminal according to claim 1, wherein the control unit changes the reception accuracy of a specific signal and determines the specific reception timing based on the reception accuracy.

4. The terminal of claim 1, wherein the control unit maintains information regarding the time of reception of the DL signal.

5. A wireless communication method for a terminal, comprising: a step of determining a specific reception timing of a downlink (DL) signal for initial access based on information regarding the reception timing of the DL signal without receiving a synchronization signal block (SSB); and a step of receiving the DL signal based on the specific reception timing.

6. A base station having: a control unit that indicates a specific reception timing of a downlink (DL) signal for initial access using information regarding the reception timing of the DL signal without transmitting a synchronization signal block (SSB); and a transmission unit that transmits the DL signal received based on the specific reception timing.

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