Terminal, radio communication method, and base station

Abstract

To improve coverage in consideration of overhead.SOLUTION: A terminal of the present invention receives at least one synchronization signal block of a first number of first synchronization signal blocks and at least one synchronization signal block of a second number of second synchronization signal blocks, assuming that the at least one synchronization signal block and the at least one synchronization signal block are quasi co-located (QCL) with each other, and a downlink first demodulation reference signal is QCL with the at least one synchronization signal block of the first number of first synchronization signal blocks. In a case that a downlink second demodulation reference signal is quasi co-located with the at least one synchronization signal block of the second number of the second synchronization signal blocks, reception is controlled assuming that the second demodulation reference signal is quasi co-located with the first demodulation reference signal.SELECTED DRAWING: Figure 11

Description

[Technical Field]

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

[0002] In Universal Mobile Telecommunications System (UMTS) networks, Long Term Evolution (LTE) was specified with the aim of achieving higher data rates and lower latency (Non-Patent Document 1). Also, LTE-Advanced (3GPP Rel. 10-14) was specified with the aim of achieving higher capacity and more advanced features than LTE (Third Generation Partnership Project (3GPP) 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) are also being considered.

[0004] In existing LTE systems (e.g., 3GPP Rel. 8-14), a user equipment (UE) transmits uplink control information (UCI) using at least one of an UL data channel (e.g., a Physical Uplink Shared Channel (PUSCH)) and an UL control channel (e.g., a Physical Uplink Control Channel (PUCCH)). [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] 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 Summary of the Invention [Problem to be solved by the invention]

[0006] In future wireless communication systems (e.g., NR), improvements in coverage are being considered.

[0007] However, narrowing / increasing the number of beams to improve coverage may increase overhead and reduce communication throughput.

[0008] Therefore, one of the objects of the present disclosure is to provide a terminal, a wireless communication method, and a base station that can improve coverage while taking overhead into consideration. [Means for solving the problem]

[0009] A terminal according to one embodiment of the present disclosure includes a receiving unit that receives at least one synchronization signal block of a first number of first synchronization signal blocks and at least one synchronization signal block of a second number of second synchronization signal blocks; and a control unit that controls reception assuming that the at least one synchronization signal block of the second number of second synchronization signal blocks is quasi-colocated (QCL) with the at least one synchronization signal block of the first number of first synchronization signal blocks, and controls initial access based on the at least one synchronization signal block of the first number of first synchronization signal blocks or the at least one synchronization signal block of the second number of second synchronization signal blocks.When a downlink first demodulation reference signal is QCL'd with the at least one synchronization signal block of the first number of first synchronization signal blocks and a downlink second demodulation reference signal is QCL'd with the at least one synchronization signal block of the second number of second synchronization signal blocks, the control unit controls reception assuming that the second demodulation reference signal is QCL'd with the first demodulation reference signal. [Effects of the Invention]

[0010] According to one aspect of the present disclosure, coverage can be improved by taking overhead into account. [Brief explanation of the drawings]

[0011] [Figure 1] 1A and 1B are diagrams showing an example of beams and coverage. [Figure 2] 2A and 2B are diagrams showing an example of a first SSB and a second SSB. [Figure 3] 3A and 3B are diagrams showing an example of the first area and the second area. [Figure 4] FIG. 4 is a diagram showing an example of mode 1-1. [Figure 5] FIG. 5 is a diagram showing an example of an SSB transmission period. [Figure 6] FIG. 6 is a diagram showing an example of mode 1-2. [Figure 7] 7A and 7B are diagrams showing an example of embodiment 1-3. [Figure 8] 8A and 8B are diagrams illustrating an example of the third embodiment. [Figure 9] FIG. 9 is a diagram illustrating an example of the fifth embodiment. [Figure 10] FIG. 10 is a diagram illustrating an example of a QCL relationship. [Figure 11] 11A and 11B are diagrams illustrating an example of a QCL relationship of a DMRS. [Figure 12] 12A and 12B are diagrams showing an example of embodiment 7-1. [Figure 13] 13A and 13B are diagrams showing an example of embodiment 7-2. [Figure 14] 14A and 14B are diagrams showing an example of embodiment 7-3. [Figure 15] 15A and 15B are diagrams showing an example of a first variation of aspect 7-3. [Figure 16] 16A and 16B are diagrams showing an example of a second variation of aspect 7-3. [Figure 17] FIG. 17 is a diagram illustrating an example of coverage. [Figure 18] 18A and 18B are diagrams showing an example of aspect 8-1. [Figure 19] FIG. 19 is a diagram showing an example of a first variation of aspect 8-1. [Figure 20] 20A and 20B are diagrams showing an example of a second variation of aspect 8-1. [Figure 21] FIG. 21 is a diagram showing an example of a third variation of aspect 8-1. [Figure 22] FIG. 22 is a diagram showing an example of aspect 8-2. [Figure 23] 23A and 23B are diagrams showing an example of aspect 8-4-2. [Figure 24] FIG. 24 is a diagram showing an example of aspect 8-5. [Figure 25] FIG. 25 is a diagram illustrating an example of the ninth embodiment. [Figure 26]FIG. 26 is a diagram illustrating an example of a beam according to the tenth embodiment. [Figure 27] FIG. 27 is a diagram showing an example of an SSB beam. [Figure 28] FIG. 28 is a diagram showing an example of variations in SSB beams. [Figure 29] 29A and 29B are diagrams showing an example of an SSB configuration. [Figure 30] 30A and 30B are diagrams showing an example of embodiment 10-2. [Figure 31] FIG. 31 is a diagram showing an example of aspect 10-4-1. [Figure 32] FIG. 32 is a diagram showing an example of aspect 10-4-2. [Figure 33] FIG. 33 illustrates an example of cyclic shifting of a PBCH-DMRS sequence. [Figure 34] FIG. 34 is a diagram showing an example of aspect 10-4-3. [Figure 35] FIG. 35 is a diagram illustrating an example of the eleventh embodiment. [Figure 36] 36A and 36B are diagrams showing an example of setting the number of repetitions according to the eleventh embodiment. [Figure 37] FIG. 37 is a diagram illustrating an example of the twelfth embodiment. [Figure 38] 38A and 38B are diagrams showing an example of embodiment 12-1. [Figure 39] 39A and 39B are diagrams showing an example of embodiment 12-1-A. [Figure 40] 40A and 40B are diagrams showing an example of aspect 12-1-B. [Figure 41] 41A and 41B are diagrams showing an example of embodiment 12-2. [Figure 42] 42A and 42B are diagrams illustrating an example of the thirteenth embodiment. [Figure 43] 43A-43C are diagrams showing an example of a Msg.3 transmission method. [Figure 44]44A and 44B are diagrams showing an example of a repetition number instruction setting. [Figure 45] FIG. 45 is a diagram illustrating an example of a schematic configuration of a wireless communication system according to an embodiment. [Figure 46] FIG. 46 is a diagram illustrating an example of the configuration of a base station according to an embodiment. [Figure 47] FIG. 47 is a diagram illustrating an example of the configuration of a user terminal according to an embodiment. [Figure 48] FIG. 48 is a diagram illustrating an example of the hardware configuration of a base station and a user terminal according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] (TCI, spatial relations, QCL) In NR, it is being considered to control the reception processing (e.g., at least one of reception, demapping, demodulation, and decoding) and transmission processing (e.g., at least one of transmission, mapping, precoding, modulation, and encoding) in the UE of at least one of a signal and a channel (referred to as signal / channel) based on the transmission configuration indication state (TCI state).

[0013] The TCI state may represent that which is applied to a downlink signal / channel, and the equivalent of the TCI state which is applied to an uplink signal / channel may be expressed as a spatial relation.

[0014] The TCI state is information about the quasi-co-location (QCL) of signals / channels, and may also be called spatial reception parameters, spatial relation information, etc. The TCI state may be configured in the UE for each channel or signal.

[0015] A QCL is an index that indicates the statistical properties of a signal / channel. For example, if a signal / channel has a QCL relationship with another signal / channel, it may mean that it can be assumed that at least one of the Doppler shift, Doppler spread, average delay, delay spread, and spatial parameter (e.g., spatial Rx parameter) is the same between these different signals / channels (i.e., they are QCLs with respect to at least one of these).

[0016] The spatial reception parameters may correspond to a reception beam (e.g., a reception analog beam) of the UE, and the beam may be determined based on a spatial QCL. A QCL (or at least one element of a QCL) in the present disclosure may be replaced with an sQCL (spatial QCL).

[0017] A plurality of types (QCL types) of QCLs may be defined. For example, four QCL types A and B may be provided, each having different parameters (or parameter sets) that can be assumed to be the same. The parameters (which may also be referred to as QCL parameters) are listed below: QCL Type A (QCL-A): Doppler shift, Doppler spread, mean delay and delay spread, QCL Type B (QCL-B): Doppler shift and Doppler spread, QCL Type C (QCL-C): Doppler shift and mean delay, · QCL Type D (QCL-D): Spatial reception parameters.

[0018] The assumption by a UE that a Control Resource Set (CORESET), channel, or reference signal has a specific QCL (e.g., QCL type D) relationship with another CORESET, channel, or reference signal may be referred to as a QCL assumption.

[0019] The UE may determine at least one of a transmit beam (Tx beam) and a receive beam (Rx beam) for a signal / channel based on the TCI condition or QCL assumption of the signal / channel.

[0020] The TCI state may be, for example, information about the QCL between the target channel (in other words, the Reference Signal (RS) for the channel) and another signal (e.g., another RS). The TCI state may be set (indicated) by higher layer signaling, physical layer signaling, or a combination thereof.

[0021] The channel / signal to which the TCI state is applied may be called a target channel / reference signal (target channel / RS), or simply a target, and the other signal may be called a reference reference signal (reference RS), source RS, or simply a reference.

[0022] The channel for which the TCI state or spatial relationship is set (specified) may be, for example, at least one of a downlink shared channel (Physical Downlink Shared Channel (PDSCH)), a downlink control channel (Physical Downlink Control Channel (PDCCH)), an uplink shared channel (Physical Uplink Shared Channel (PUSCH)), and an uplink control channel (Physical Uplink Control Channel (PUCCH)).

[0023] Furthermore, the RS that has a QCL relationship with the channel may be at least one of, for example, a Synchronization Signal Block (SSB), a Channel State Information Reference Signal (CSI-RS), a Sounding Reference Signal (SRS), a CSI-RS for tracking (also called a Tracking Reference Signal (TRS)), a QCL detection reference signal (also called a QRS), and a Demodulation Reference Signal (DMRS).

[0024] An SSB is a signal block that includes at least one of a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS), and a Physical Broadcast Channel (PBCH). An SSB may also be referred to as an SS / PBCH block.

[0025] An RS of QCL type X in a TCI state may refer to an RS that has a relationship of QCL type X with (the DMRS of) a certain channel / signal, and this RS may be called a QCL source of QCL type X in the TCI state.

[0026] In the TCI state of the DMRS of the PDCCH / PDSCH, the type A RS is always configured (in both FR1 and FR2), and the type D RS may be configured (mainly in FR2).

[0027] Type-A RSs are used for long-term channel information measurements, such as channel estimation for DMRSs. Measuring DMRSs only provides instantaneous measurements, and does not provide Doppler information. UEs obtain Type-A information (Doppler shift, Doppler spread, average delay, and delay spread) by measuring periodic RSs (e.g., TRSs) configured as Type-A RSs, and use this information to receive PDCCH / PDSCH.

[0028] The Type D RS is used to notify the base station of the transmit spatial domain filter (analog beam). The UE selects the receive spatial domain filter by measuring the RS (e.g., TRS) configured as the Type D RS, and receives the PDCCH / PDSCH using this receive spatial domain filter.

[0029] (Initial Access Procedures) In the initial access procedure, the UE (RRC_IDLE mode) receives the SS / PBCH block (SSB), 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). After that, when the base station (network) transmits an ACK for Msg.4 from the UE, an RRC connection is established (RRC_CONNECTED mode).

[0030] SSB reception includes PSS detection, SSS detection, PBCH-DMRS detection, and PBCH reception. PSS detection detects part of the physical cell ID (PCI), detects (synchronizes) OFDM symbol timing, and performs (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).

[0031] SSB has a bandwidth of 20 RB and a time of 4 symbols. The transmission period of SSB can be set to {5, 10, 20, 40, 80, 160} ms. In the half frame, multiple symbol positions of SSB are specified based on the frequency range (FR1, FR2).

[0032] 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.

[0033] The system information consists of the MIB, RMSI (SIB1), and other system information (OSI) carried by the PBCH. SIB1 contains information for RACH configuration and RACH procedures. The time / frequency resource relationship between the SSB and the PDCCH monitoring resource for SIB1 is configured by the PBCH.

[0034] A base station using beam correspondence transmits multiple SSBs using multiple beams in each SSB transmission period. The multiple SSBs have multiple SSB indices. When a UE detects an SSB, it transmits a PRACH in the RACH occasion associated with that SSB index and receives an RAR in the RAR window.

[0035] (Beam and Coverage) In high-frequency bands, if beamforming is not applied to synchronization signals / reference signals, coverage will be narrow, making it difficult for UEs to find base stations. On the other hand, if beamforming is applied to synchronization signals / reference signals to ensure coverage, a strong signal will reach a specific direction, but the signal will be even more difficult to reach in other directions (Figure 1A). If the base station does not know the direction of the UE before connecting, it is impossible to transmit synchronization signals / reference signals using beams pointing only in the appropriate direction. One possible method is for the base station to transmit multiple synchronization signals / reference signals, each with a beam pointing in a different direction, and for the UE to recognize which beam it has found. Using thin (narrow) beams for coverage requires transmitting many synchronization signals / reference signals, which increases overhead and may reduce frequency utilization efficiency.

[0036] In order to reduce the number of beams (synchronization signals / reference signals) and reduce overhead, using a thick (wide) beam results in a narrower coverage area (Figure 1B).

[0037] In future wireless communication systems (e.g., 6G), it is expected that the use of frequency bands such as millimeter waves and terahertz waves will become more widespread. It is conceivable that communication services will be provided by constructing cell areas / coverage using multiple narrow beams.

[0038] It is possible to expand the coverage area by using the existing FR2, or to use a higher frequency band than the existing FR2. To achieve this, it is desirable to improve beam management in addition to multi-TRP, reconfigurable intelligent surface (RIS), etc.

[0039] In current 5G NR, the maximum number of synchronization signal blocks (SSBs) is 64. Because it is necessary to cover the cell area (surface) using a maximum of 64 beams, it is difficult to use narrow beams. To use a large number of narrow beams, the following beam management methods 1 and 2 can be considered.

[0040] [Beam management method 1] Use more than 64 SSBs (the maximum number of SSBs exceeds 64). Simply increasing the number of SSBs may increase SSB overhead / initial access delay.

[0041] [Beam management method 2] Use up to 64 SSBs (the maximum number of SSBs is 64). Reduce the area (surface) covered by one cell / sector. Inter-cell / sector interference and fast / frequent handover between cells / sectors may become problems.

[0042] Therefore, the present inventors came up with a method for reducing overhead / initial access delay.

[0043] 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.

[0044] In the present disclosure, "A / B / C" and "at least one of A, B, and C" may be read as interchangeable. In the present disclosure, cell, serving cell, CC, carrier, BWP, DL BWP, UL BWP, active DL BWP, active UL BWP, and band may be read as interchangeable. In the present disclosure, index, ID, indicator, and resource ID may be read as interchangeable. In the present disclosure, sequence, list, set, group, group, cluster, subset, etc. may be read as interchangeable. In the present disclosure, support, control, controllable, operate, and operable may be read as interchangeable.

[0045] In the present disclosure, the terms configure, activate, update, indicate, enable, specify, and select may be read interchangeably.

[0046] In the present disclosure, higher layer signaling may be, for example, any one of Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information, etc., or a combination thereof. In the present disclosure, RRC, RRC signaling, RRC parameters, higher layer parameters, RRC information elements (IEs), RRC messages, and settings may be read interchangeably.

[0047] The MAC signaling may use, for example, a MAC Control Element (MAC CE), a MAC Protocol Data Unit (PDU), etc. The 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.

[0048] In the present disclosure, MAC CE and activation / deactivation command may be read interchangeably.

[0049] In this disclosure, the terms beam, spatial domain filter, spatial setting, TCI state, UL TCI state, unified TCI state, unified beam, common TCI state, common beam, TCI assumption, QCL assumption, QCL parameter, spatial domain receive filter, UE spatial domain receive filter, UE receive beam, DL beam, DL receive beam, DL precoding, DL precoder, DL-RS, QCL type D RS in TCI state / QCL assumption, QCL type A RS in TCI state / QCL assumption, spatial relationship, spatial domain transmit filter, UE spatial domain transmit filter, UE transmit beam, UL beam, UL transmit beam, UL precoding, UL precoder, PL-RS, antenna port, panel group, and beam group may be interchangeable. In this disclosure, the terms QCL type X-RS, DL-RS associated with QCL type X, DL-RS with QCL type X, source of DL-RS, SSB, CSI-RS, and SRS may be interchangeable.

[0050] In the present disclosure, CSI-RS, NZP-CSI-RS, periodic (P)-CSI-RS, P-TRS, semi-persistent (SP)-CSI-RS, aperiodic (A)-CSI-RS, TRS, tracking CSI-RS, CSI-RS having TRS information (higher layer parameter trs-Info), NZP CSI-RS resources in an NZP CSI-RS resource set having TRS information, NZP-CSI-RS resources in an NZP-CSI-RS resource set consisting of multiple NZP-CSI-RS resources of the same antenna port, and TRS resources may be read as interchangeable terms.

[0051] In the present disclosure, Msg.1, PRACH, random access preamble, preamble, message may be interchangeable. In the present disclosure, Msg.2, Msg.2 PDCCH, random access response (RAR), PDSCH including RAR, message may be interchangeable. In the present disclosure, Msg.3, PUSCH scheduled by RAR UL grant, message may be interchangeable. In the present disclosure, Msg.4, Msg.4 PDCCH, PDSCH including UE contention resolution identity, message may be interchangeable.

[0052] (Wireless communication method) In the present disclosure, failure may be interpreted as a specific number of failures. The specific number of failures may be defined in the specifications, or may be notified / set by broadcast / SIB / upper layer signaling, etc. The specific number of failures may be 1.

[0053] In the present disclosure, beam sweeping, repeated transmission with beam change, and multiple repeated transmissions using different beams may be read interchangeably.

[0054] In the present disclosure, the terms "not detecting / receiving an SSB (first SSB / second SSB)" and "the received power / received quality of the SSB is equal to or less than a threshold (or is below a threshold)" may be interchangeable. In the present disclosure, the terms "detecting / receiving an SSB (first SSB / second SSB)" and "the received power / received quality of the SSB is equal to or greater than a threshold (or exceeds a threshold)" may be interchangeable.

[0055] In the present disclosure, the terms wide beam, thick beam, first SSB, first SSB index, PSS / SSS, and PSS / SSS beam may be interchangeable. In the present disclosure, the terms narrow beam, thick beam, second SSB, second SSB index, PBCH / PBCH-DMRS, and PBCH / PBCH-DMRS beam may be interchangeable.

[0056] First Embodiment A first SSB (legacy SSB, 64 SSBs, first number of SSBs) may cover a first area (FIG. 2A), and a second SSB (RS different from the legacy SSBs, second number of SSBs) may cover a second area (FIG. 2B). The first UE may receive the first SSB, and the second UE may receive the second SSB. The first UE may be a legacy (Rel. 15 / 16 NR) UE.

[0057] The first SSB (primary SSB) may be a legacy (Rel. 15 / 16 NR) SSB. The first SSB may be transmitted periodically. The first SSB may be the first set of SSBs. The maximum number of first SSBs may be 64.

[0058] The second SSB (secondary SSB) may cover an area not covered by the first SSB. The second SSB may be transmitted periodically or aperiodically. The second SSB may be a second set of SSBs. The number of second SSBs (second number) may be different from or the same as the number of first SSBs (first number).

[0059] In the present disclosure, the second SSB may be an RS other than an SSB, may be a CSI-RS, or may be a tracking reference signal (TRS, tracking CSI-RS).

[0060] In 3D MIMO, each beam defines an area (surface), and the second area covered by the second SSB (FIG. 3B) may not include part or all of the first area covered by the first SSB (FIG. 3A).

[0061] The beam used to transmit the second SSB may be narrower than the beam used to transmit the first SSB.

[0062] The first and second SSBs may be transmitted on the same carrier / CC / BWP.

[0063] <<Aspect 1-1>> The first SSB may be transmitted periodically.

[0064] The second SSB may be transmitted periodically. If the second SSB is transmitted periodically, the transmission period of the second SSB may be different from the transmission period of the first SSB. The transmission period of the second SSB may be greater than the transmission period of the first SSB.

[0065] The second SSB may be transmitted aperiodically (FIG. 4).

[0066] For each primary SSB, a specific number of secondary SSBs may be transmitted. For example, the specific number may be 4, 6, 8, or any other number. If 64 primary SSBs are transmitted and the specific number is 6, then 384 secondary SSBs may be transmitted.

[0067] If the first SSB and the second SSB are transmitted periodically and the transmission period of the second SSB is greater than the transmission period of the first SSB (FIG. 5), the UE may follow at least one of the following initial access operations 1 and 2.

[0068] [Initial access behavior 1] A UE that can detect the first SSB performs initial access using the first SSB. Because the frequency of the first SSB is higher than the frequency of the second SSB, the initial access delay for a UE using the first SSB is small.

[0069] [Initial access behavior 2] UEs that can detect the second SSB perform initial access using the second SSB. Because the frequency of the second SSB is lower than that of the first SSB, the initial access delay of UEs using the second SSB is longer than that of UEs using the first SSB. Assuming that most UEs are located within the first area, the impact of the initial access delay can be reduced.

[0070] <<Aspect 1-2>> The first SSB does not have to be transmitted periodically. The first SSB may be repeatedly transmitted a specific number of times (M times) at specific intervals. The specific interval may be one frame or more, or 20 ms or more.

[0071] The first SSB may be repeatedly transmitted M times and the second SSB may be repeatedly transmitted N times for each specific time period. The specific time period may be equal to or greater than the specific period × (M + N).

[0072] Either the first SSB or the second SSB may be transmitted at each specific period. In the example of Figure 6, SSB transmission opportunities #0 to #4 occur at specific periods (e.g., 20 ms). The first SSB is transmitted at each of SSB transmission opportunities #0 to #2, and the third SSB is transmitted at each of SSB transmission opportunities #3 to #4.

[0073] <<Aspects 1-3>> If the first SSB is transmitted using a first beam and the second SSB is transmitted using a second beam, and the second beam is narrower than the first beam, the number of second SSBs may be greater than the number of first SSBs.

[0074] A first SSB may be transmitted every first period, and a second SSB may be transmitted every second period. The second period may be different from the first period. The first SSBs transmitted in one first period may be referred to as a first SSB set. The second SSBs transmitted in one second period may be referred to as a second SSB set.

[0075] [Aspect 1-3-1] The number of second SSBs (in the second SSB set) per second period is equal to the number of first SSBs (in the first SSB set) per first period.

[0076] All secondary SSBs (secondary SSBs corresponding to all secondary SSB indices) may be transmitted over multiple second periods (multiple secondary SSB sets). In other words, some secondary SSBs (secondary SSB subsets) may be transmitted in each second period.

[0077] In each first period (each primary SSB set), all primary SSBs (primary SSBs corresponding to all primary SSB indices) may be transmitted.

[0078] The transmission duration (length of time) of the second SSB in each second period may be different from the transmission duration (length of time) of the first SSB in each first period.

[0079] In the example of Figure 7A, the number of first SSBs is 64 and the number of second SSBs is 256. 64 first SSBs are transmitted in each first period. 64 different second SSBs are transmitted in each second period, resulting in 256 second SSBs being transmitted over four second periods.

[0080] [Aspect 1-3-2] The number of second SSBs (in the second SSB set) per second period is different from the number of first SSBs (in the first SSB set) per first period.

[0081] The transmission duration (length of time) of the second SSB in each second period may be different from the transmission duration (length of time) of the first SSB in each first period. The transmission duration (length of time) of the second SSB in each second period may be longer than the transmission duration (length of time) of the first SSB in each first period.

[0082] In the example of Figure 7B, the number of primary SSBs is 64 and the number of secondary SSBs is 256. 64 primary SSBs are transmitted in each primary period. 256 secondary SSBs are transmitted in each secondary period.

[0083] [Aspect 1-3-3] The subcarrier spacing of the second SSBs may be different from the subcarrier spacing of the first SSBs. The number of second SSBs (in the second SSB set) per second period may be equal to the number of first SSBs (in the first SSB set) per first period, and the transmission duration (length of time) of the second SSBs per second period may be different from the transmission duration (length of time) of the first SSBs per first period. The number of second SSBs (in the second SSB set) per second period may be different from the number of first SSBs (in the first SSB set) per first period, and the transmission duration (length of time) of the second SSBs per second period may be equal to the transmission duration (length of time) of the first SSBs per first period.

[0084] The subcarrier spacing of the second SSBs may be equal to the subcarrier spacing of the first SSBs, the number of second SSBs (in the second SSB set) per second period may be different from the number of first SSBs (in the first SSB set) per first period, and the transmission duration (length of time) of the second SSBs per second period may be different from the transmission duration (length of time) of the first SSBs per first period.

[0085] [Aspect 1-3-4] A combination of multiple aspects from aspects 1-3-1 to 1-3-3 may be used. For example, the transmission duration (length of time) of the second SSB in each second period may be longer than the transmission duration (length of time) of the first SSB in each first period, and all second SSBs (second SSBs corresponding to all second SSB indices) may be transmitted over multiple second periods (multiple second SSB sets).

[0086] <<Aspects 1-4>> In existing NR, information on cell-defined SSBs is signaled by a system information block (SIB). Information on additional SSBs for measurement may be signaled by a measurement object information element (measObject).

[0087] At least one of the SIB and the serving cell configuration (servingCellConfig) may include information / configuration of the second SSB. At least one of the SIB and the serving cell configuration may include information / configuration of the first SSB.

[0088] The UE may perform reception / detection / measurement operations for the second SSB (after RRC connection establishment / in RRC_CONNECTED mode) using information about the second SSB configured / notified by at least one of the SIB and the serving cell configuration.

[0089] According to this embodiment, by transmitting the second SSB in addition to the first SSB, it is possible to achieve an expansion of coverage, a reduction in overhead, and the like.

[0090] <Second embodiment> <<Aspect 2-1>> The UE may attempt to receive / detect the first SSB, which is transmitted periodically / non-periodically. If the UE can receive / detect the first SSB, it may perform initial access using only the first SSB (without using the second SSB). If the UE can receive / detect the first SSB, it may perform initial access using either the first SSB or the second SSB. For example, if initial access based on the first SSB fails, the UE may perform initial access using the second SSB.

[0091] If the UE cannot detect the first SSB (e.g., the UE cannot detect the first SSB within the detection time), it may attempt to receive / detect the second SSB. A UE that cannot receive / detect the first SSB may perform initial access using only the second SSB (without the first SSB).

[0092] At least one of the following resource information for the second SSB, namely frequency information 1 and 2, time information 1 and 2, may be specified in the specification, may be broadcast, or may be set (by higher layer signaling).

[0093] [Frequency information 1] The frequency information of the second SSB may be the same as the frequency information of the first SSB.

[0094] The frequency information of the second SSB may include a frequency (synchronization raster, sync raster) that the UE searches for the PSS / SSS during initial access. The frequency information of the second SSB may be specified in a specification for each frequency range (FR1, FR2, etc.).

[0095] The frequency at which the UE searches for the PSS / SSS other than at the time of initial access may be configured / instructed by the network.

[0096] [Frequency information 2] The frequency information of the second SSB may be different from the frequency information of the first SSB, and may be set / instructed by the network.

[0097] The frequency information of the second SSB may include the relationship between the frequency of the first SSB and the frequency of the second SSB (relative position, frequency offset of the first SSB from the detected RB, etc.).

[0098] [Time information 1] The time information of the second SSB may be the same as the time information of the first SSB.

[0099] The time information of the second SSB may include a period (eg, one of a plurality of values ​​including at least one of {5, 10, 20, 40, 80, 160} ms). The UE may blindly detect the period.

[0100] [Time information 2] The time information of the second SSB may be different from the time information of the first SSB, and may be set / instructed by the network.

[0101] The time information of the second SSB may include the relationship between the time of the first SSB and the time of the second SSB (relative position, time offset from the detected symbol of the first SSB, relationship between the period of the first SSB and the period of the second SSB, the period of the second SSB being the same as the period of the first SSB, etc.).

[0102] If the UE detects the first SSB and encounters problems with subsequent operations (eg, Msg. 3 transmission), it may detect the second SSB and perform subsequent operations based on the second SSB.

[0103] <<Aspect 2-2>> The UE may use the same SSB index derivation rule for the first and second SSBs. The UE can derive frame timing without distinguishing between the first and second SSBs. If the first and second SSBs are transmitted in the same half-frame, the UE may use a method (e.g., DMRS sequence, field / bit in PBCH) to distinguish all SSB indices for the first and second SSBs.

[0104] The UE may use different SSB index derivation rules for the first SSB and the second SSB. The UE can distinguish between the first SSB and the second SSB. The number of SSB indices for the first SSB and the second SSB can be reduced. The UE may use different frame timing derivation methods for the first SSB and the second SSB.

[0105] According to this embodiment, the UE can properly receive / detect the first SSB / second SSB.

[0106] <Third embodiment> A UE that detects the first SSB may transmit a PRACH (Msg. 1) on a PRACH occasion (RACH occasion) corresponding to the detected first SSB (FIG. 8A).

[0107] A UE that does not detect the first SSB (e.g., a UE that fails to detect the first SSB within the detection time) may detect the second SSB and transmit a PRACH on the PRACH occasion corresponding to the detected second SSB (FIG. 8B). The correspondence between the second SSB and the PRACH occasion may be specified, broadcast, or configured by higher layer signaling.

[0108] A UE that detects the first SSB may also detect the second SSB and transmit a PRACH on the PRACH occasion corresponding to the detected second SSB.

[0109] A UE that transmits a PRACH on a PRACH occasion corresponding to the second SSB may receive a random access response (RAR) within the RAR window corresponding to the second SSB (FIG. 8B). The RAR window corresponding to the second SSB may be specified, broadcast, or configured by higher layer signaling.

[0110] According to this embodiment, the UE can appropriately perform the random access procedure based on the reception of the first SSB or the second SSB.

[0111] <Fourth embodiment> A UE within the coverage (first area) of the first SSB may follow at least one of the following SSB-related actions 1 and 2.

[0112] [SSB related operations 1] A UE that can detect the first SSB does not need to detect the second SSB or transmit a PRACH in the PRACH occasion corresponding to the second SSB. This eliminates the need to provide multiple PRACH occasions / resources corresponding to the second SSB (especially in contention-based random access (CBRA)), allowing for decentralized PRACH occasions / resources.

[0113] [SSB related operations 2] In a network that transmits a second SSB, a UE that can detect the first SSB may detect the second SSB and transmit a PRACH on the PRACH occasion corresponding to the second SSB. The accuracy of the beam (QCL) information obtained from the second SSB is higher (narrower) than the accuracy of the beam information obtained from the first SSB. By using the beam information of the second SSB, the UE can detect the DMRS with higher accuracy than when using the beam information of the first SSB, thereby improving the reception performance of the PDSCH / PDCCH and the transmission performance of the PUSCH / PUCCH.

[0114] This embodiment can improve the performance of the UE within the coverage of the first SSB.

[0115] <Fifth embodiment> This embodiment relates to a QCL using a first SSB and a second SSB.

[0116] The QCL relationship using the first SSB and the second SSB may be specified in the specification or may be notified to the UE. The QCL type / QCL chain representing the QCL inclusion relationship may be specified in the specification or may be notified to the UE. One or more second SSBs may be associated with (included in) one first SSB.

[0117] In the example of Figure 9, a first SSB (wide beam) having a first SSB index #1-1 and a second SSB (narrow beam) having second SSB indexes #2-1 to #2-4 are transmitted. As shown in Figure 10, the QCL relationship of the second SSB indexes #2-1 to #2-4 points to (references) the first SSB index #1-1. If the QCL relationship is Type D, the UE can use the receive beam (spatial receive parameters, spatial domain receive filter) determined by receiving the first SSB index #1-1 for receiving the second SSB indexes #2-1 to #2-4. If the QCL relationship is Type A, the UE can use the QCL parameters (Doppler shift, Doppler spread, average delay, delay spread) determined by receiving the first SSB index #1-1 for receiving the second SSB indexes #2-1 to #2-4.

[0118] The reference (source) of a QCL relationship may be expressed as encompassing the reference (target) of that QCL relationship. The UE may determine the reference (source) of the QCL relationship from the reference (target) based on the QCL relationship. For example, the UE may determine the associated first SSB from the detected second SSB and use the first SSB as the QCL (beam) for the channel / RS. The UE may receive multiple second SSBs associated with the same first SSB as well as narrow beams.

[0119] If the QCL source of DMRS#1 of a certain PDSCH / PDCCH#1 is SSB#1-1 and the QCL source of DMRS#2 of another PDSCH / PDCCH#2 is SSB#2-1, the question arises as to whether the UE can receive PDSCH / PDCCH#1 and PDSCH / PDCCH#2 simultaneously (especially in FR2).

[0120] In the example of Figure 11A, the QCL relationship of DMRS#1 references TRS#1, and the QCL relationship of TRS#1 references SSB#1-1. SSB#1-1, which is the ultimate reference of the QCL relationship of DMRS#1, may be referred to as the root SSB of DMRS#1, the root QCL source, etc. The QCL relationship of DMRS#2 references TRS#2, and the QCL relationship of TRS#2 references SSB#2-1. SSB#2-1, which is the ultimate reference of the QCL relationship of DMRS#2, may be referred to as the root SSB of DMRS#2, the root QCL source, etc.

[0121] It may be specified that if the SSB index of the root SSB between DMRS#1 and DMRS#2 is different, the UE assumes that DMRS#1 and DMRS#2 are not QCL related. In this case, in FR2, if PDSCH / PDCCH#1 and PDSCH / PDCCH#2 are transmitted in the same symbol, the UE may not be able to receive both.

[0122] Even if the SSB indexes of the root SSBs of DMRS#1 and DMRS#2 are different, if the QCL source of DMRS#1 and the QCL source of DMRS#2 are in a QCL relationship, the UE may assume that DMRS#1 and DMRS#2 are in a QCL relationship. This case may be the case where the beam of the QCL source of DMRS#1 (SSB#1, first SSB) includes (contains) the beam of the QCL source of DMRS#2 (SSB#2, second SSB), as shown in FIG. 11B. This case may be expressed as DMRS#1 and DMRS#2 having an inclusive QCL relationship. In this case, if PDSCH / PDCCH#1 and PDSCH / PDCCH#2 are transmitted in the same symbol in FR2, the UE may be able to receive both.

[0123] According to this embodiment, the UE can properly recognize the QCL relationship between the first SSB / second SSB.

[0124] Sixth Embodiment This embodiment relates to the QCL relationship between the first SSB / second SSB and the DMRS of the PDSCH / PDCCH.

[0125] If the UE transmits a PRACH on a PRACH occasion corresponding to the first SSB / second SSB, the UE may assume that the DMRS of the PDSCH / PDCCH has a QCL relationship with the first SSB / second SSB corresponding to the PRACH occasion used for transmission.

[0126] The TCI state may be set by higher layer signaling, and the QCL relationship of the DMRS of the PDSCH / PDCCH may be set / notified by the TCI state. The first SSB / second SSB may be directly referenced / set as the QCL source of the TCI state of the DMRS. Another TRS / CSI-RS may be referenced / set as the QCL source of the TCI state of the DMRS, and the first SSB / second SSB may be referenced / set as the QCL source of this TRS / CSI-RS.

[0127] According to this embodiment, the UE can appropriately use the first SSB / second SSB in accordance with the QCL relationship of the DMRS of the PDSCH / PDCCH.

[0128] Seventh Embodiment It is conceivable that the base station transmits the second SSB only when necessary. In this case, it is preferable for the base station to know whether there are UEs within its coverage area that require the second SSB. However, it is difficult for the base station to determine whether a UE can perform initial access using only the first SSB or whether it requires the second SSB.

[0129] This embodiment relates to a second SSB transmission triggered by the UE.

[0130] <<Aspect 7-1>> If the UE can detect the first SSB, the UE may transmit a PRACH using the PRACH occasion corresponding to the first SSB and receive an RAR in the RAR window (FIG. 12A).

[0131] If the UE cannot detect (find) the first SSB (due to a failed correlation detection or a received power below a threshold), it may transmit a dedicated PRACH for failed detection indication in one or more dedicated PRACH occasions for failed detection indication (FIG. 12B). The dedicated PRACH occasions may be specified in the specification or configured by higher layer signaling.

[0132] The base station that receives the dedicated PRACH may transmit multiple second SSBs (while sweeping the beam). The UE may measure the received power of the multiple second SSBs (while sweeping the beam) and transmit the PRACH in the PRACH occasion corresponding to the second SSB with the highest received power.

[0133] The UE may transmit multiple dedicated PRACHs on multiple dedicated PRACH occasions, respectively, and may use different transmit beams for the multiple dedicated PRACH transmissions (perform beam sweeping of the dedicated PRACHs).

[0134] The base station may attempt to receive multiple PRACHs in multiple dedicated PRACH occasions, respectively. The base station may use different beams (narrow beams) to receive the multiple dedicated PRACHs (perform beam sweeping). If a dedicated PRACH is detected, the base station may transmit a second SSB in the direction of the detected dedicated PRACH (using the beam corresponding to the detected dedicated PRACH).

[0135] After detecting the first SSB and transmitting the dedicated PRACH, the UE may search for the second SSB within a specific period thereafter (and may measure the received power of multiple second SSBs).

[0136] The base station may select a secondary SSB corresponding to the detected dedicated PRACH occasion and transmit only the selected secondary SSB.

[0137] Aspect 7-2 After transmitting a dedicated PRACH in one or more dedicated PRACH occasions for the first SSB detection failure notification, the UE may receive an RAR using the resource (beam / RAR window) corresponding to the beam used for the dedicated PRACH (Figure 13A). This eliminates the need to transmit a second SSB, thereby reducing overhead.

[0138] The UE may receive the RAR using different receive beams (while sweeping the receive beams) in multiple RAR windows (as in FIG. 20A of aspect 8-1 described later). In this case, it may be assumed that the UE receives the RAR using any one of the one or more beams used for the dedicated PRACH.

[0139] Multiple RAR windows may be specified in the specification or configured by higher layer signaling. The multiple RAR windows may correspond to multiple dedicated PRACH occasions / dedicated PRACHs, respectively (FIG. 13B). The UE may attempt reception / measurement / detection in the RAR window corresponding to the transmitted dedicated PRACH using a receive beam corresponding to the transmit beam of the dedicated PRACH.

[0140] Aspect 7-3 Aspects 7-1 and 7-2 may be combined.

[0141] The UE may transmit a dedicated PRACH in one or more dedicated PRACH occasions, perform measurements on multiple second SSBs, and then receive an RAR (FIG. 14A). In this case, repeated transmission of the RAR (beam sweeping) may be performed according to aspect 8-1 described below.

[0142] After transmitting the dedicated PRACH in one or more dedicated PRACH occasions, the UE may select one of a plurality of RAR windows based on reception / measurement / detection of a plurality of second SSBs and receive the RAR in the selected RAR window. The selected RAR window may correspond to a second SSB with the highest received power among the plurality of second SSBs. One receive beam of the plurality of second SSBs may correspond to the receive beam of the RAR (FIG. 14B).

[0143] As shown in Figure 15A, the order in the time domain may be multiple first SSBs, multiple second SSBs, multiple dedicated PRACH occasions, and RAR / RAR windows. One second SSB beam may correspond to one dedicated PRACH occasion / dedicated PRACH beam, and one RAR beam.

[0144] As shown in Figure 15B, the order in the time domain may be multiple first SSBs, multiple second SSBs, multiple dedicated PRACH occasions, and multiple RAR windows. One second SSB beam may correspond to one dedicated PRACH beam / occasion and one RAR beam / window.

[0145] As shown in Figure 16A, the UE may measure multiple secondary SSBs, select one secondary SSB based on the results of receiving / detecting / measuring the multiple secondary SSBs, select a dedicated PRACH occasion corresponding to the selected secondary SSB from multiple dedicated PRACH occasions, and transmit a dedicated PRACH on the selected dedicated PRACH occasion. Here, the selected secondary SSB may be the secondary SSB corresponding to the highest received power among the multiple secondary SSBs. A beam of one secondary SSB may correspond to a beam / dedicated PRACH occasion of the dedicated PRACH and a beam / RAR window of the RAR.

[0146] As shown in Figure 16B, the order in the time domain may be multiple first SSBs, multiple second SSBs, multiple dedicated PRACH occasions, and multiple RAR windows. One second SSB beam may correspond to one dedicated PRACH beam / occasion and one RAR beam / window.

[0147] Any of aspects 7-1 to 7-3 may be applied to at least one of initial access, an operation of searching for an SCell on a different frequency (different frequency band), UL synchronization, RRC reconfiguration, and recovery from RRC idle. A dedicated PRACH occasion for notification of detection failure of the first SSB may be configured by an RRC IE.

[0148] The first SSB, the PRACH occasion corresponding to the first SSB, and the RAR window corresponding to the first SSB may be in the same BWP / CC or in different BWP / CCs.

[0149] The first SSB, the second SSB, the PRACH occasion corresponding to the second SSB, the RAR window corresponding to the second SSB, and the dedicated PRACH occasion for notification of detection failure for the first SSB may be in the same BWP / CC or in different BWP / CCs.

[0150] According to this embodiment, the overhead of the second SSB can be reduced.

[0151] Eighth Embodiment As shown in the example of Figure 17, it may be assumed that Msg.3 (Msg.3 PUSCH, PUSCH scheduled by RAR UL grant) has the smallest coverage among the channels / signals in initial access. The UL transmission power is smaller than the DL transmission power, and Msg.3 has a larger number of information bits than PRACH / Msg.4 (PDSCH including UE contention resolution identity) HARQ-ACK, resulting in a smaller coverage.

[0152] It is possible that the initial transmission of Mg.3 from many UEs is received correctly, but that Mg.3 from UEs outside the Mg.3 coverage area is incorrect. Below, we will describe an improvement method for UEs outside the Mg.3 coverage area.

[0153] This embodiment may also be applied to a wireless communication system in which the second SSB is not transmitted.

[0154] <<Aspect 8-1>> A UE that fails to transmit the initial Msg.3 may send multiple repetitions of Msg.3, which may be inter-slot or intra-slot.

[0155] Only UEs configured / instructed by broadcast / higher layer signaling / Msg.2 (RAR UL grant) / scheduling of Msg.3 retransmissions may send multiple repetitions of Msg.3 retransmissions.

[0156] A UE that fails a certain number of Mg.3 transmissions (initial transmissions / retransmissions) may send multiple repetitions of Mg.3 retransmissions.

[0157] The beam used for retransmission (repetition) of Msg.3 may be the same as the beam used for the initial transmission.

[0158] The beam used for retransmission (repetition) of Msg.3 may be different from the beam used for the initial transmission. For example, a different transmission beam may be used for each of the multiple repetitions (beam sweeping may be used).

[0159] The example of FIG. 18A shows a case where reception of the first SSB, transmission of a PRACH in a PRACH occasion corresponding to the first SSB, reception of Msg.2 (RAR), and initial transmission of Msg.3 are successful.

[0160] In the example of FIG. 18B, if the initial transmission of Msg.3 fails, the UE sends repeated retransmissions of Msg.3.

[0161] If the initial transmission of Msg.3 fails, the UE may receive a DCI to schedule a retransmission of Msg.3. If Msg.4 is not received within a certain time period after the initial transmission of Msg.3, the UE may determine that the initial transmission of Msg.3 failed and may send a retransmission of Msg.3 without scheduling.

[0162] The UE may transmit multiple repetitions of the Msg.3 initial transmission. As shown in the example of Figure 19, the multiple repetitions / number of repetitions of the Msg.3 initial transmission may be indicated by the Mg.2 PDCCH / RAR (PDSCH) or DCI indicating retransmission. The multiple repetitions of the Msg.3 initial transmission may be indicated or specified, similar to aspect 8-2 described below.

[0163] When Msg.3 is retransmitted, the second SSB may not be transmitted. Multiple repetitions of Msg.2 PDCCH / RAR may be transmitted using different beams (beam sweeping). For example, if the base station recognizes that the reception quality of the PRACH is poor, beam sweeping may be performed after Msg.2 PDCCH.

[0164] As shown in the example of Figure 20A, beam sweeping may be used for multiple repetitions of the RAR. The UE may transmit a Msg.2 PDCCH using the detected beam of the first SSB, and multiple repetitions of the RAR may be scheduled by the Msg.2 PDCCH, and beam sweeping may be used for the multiple repetitions.

[0165] As shown in the example of Figure 20B, beam sweeping may be used for multiple repetitions of Msg.2 PDCCH and multiple repetitions of RAR. Beam sweeping may be used for the repetitions of Msg.2 PDCCH, multiple repetitions of RAR may be scheduled by the multiple repetitions of Msg.2 PDCCH, and beam sweeping may be used for the multiple repetitions of RAR.

[0166] As shown in the example of Figure 21, beam sweeping may be used for multiple RAR windows. Multiple RAR windows may be specified or configured / instructed. The UE may attempt to receive Msg.2 PDCCH and RAR within the RAR window using the beam corresponding to that RAR window. After receiving the RAR, the UE may transmit Msg.3 using the resources / beam scheduled by that RAR.

[0167] 《Aspect 8-2》 A UE that has sent multiple repetitions of initial / retransmissions of Msg.3 may attempt to detect Msg.4 on multiple occasions.

[0168] As shown in the example of Figure 22, multiple beams are used for multiple repetitions of Msg.3. Multiple occasions of Msg.4 correspond to multiple repetitions of Msg.3. The base station may select one repetition based on reception / measurement / detection of multiple repetitions of Msg.3 and transmit Mg.4 using the occasion / beam corresponding to the selected repetition among the multiple occasions / beams of Msg.4.

[0169] If the UE can detect Msg.4 in one occasion, it may use the DL / UL beam corresponding to that occasion for subsequent reception / transmission (it may be assumed that the DL / UL beam corresponding to that occasion is DMRS and QCL of PDSCH / PDCCH). This operation allows the UE and the base station to have a common understanding of the beam to be used.

[0170] Aspect 8-3 This aspect relates to whether multiple repetitions (number of repetitions, aggregation factor) are transmitted in the initial transmission / retransmission of Msg.3.

[0171] Whether multiple repetitions are transmitted (the number of repetitions) may be specified in the specifications, or may be notified / set by broadcast / SIB / upper layer signaling, etc.

[0172] The number of repetitions of Msg.3 retransmission may be specified in the specifications, or may be notified / set by broadcast / SIB / upper layer signaling, etc. Whether multiple repetitions of Msg.3 retransmissions are transmitted (the number of repetitions) may be set separately from whether multiple repetitions of Msg.3 are transmitted (the number of repetitions). The number of repetitions of the initial transmission of Msg.3 does not have to be limited to 1. The number of repetitions of the initial transmission of Msg.3 may be specified in the specifications, or may be notified / set by broadcast / SIB / upper layer signaling, etc. The number of repetitions may be changed (increased) depending on the number of times Msg.3 is transmitted.

[0173] The number of repetitions for Msg.3 retransmission may be greater than the number of repetitions for the initial transmission of Msg.3. By applying a larger number of repetitions only to UEs that fail to transmit Msg.3 the first time, only necessary UEs can transmit as many repetitions as necessary, improving resource utilization efficiency.

[0174] At least one of Msg.2, the Msg.3 RAR UL grant, and the DCI scheduling the Msg.3 retransmission may indicate whether multiple repetitions of the Msg.3 retransmission are sent (the number of repetitions).

[0175] The base station can instruct repetition for each UE to which Msg.3 is transmitted, allowing for more flexible operation. For example, the base station may instruct multiple retransmissions of Msg.3 if the received power / quality of the initial Msg.3 transmission is below a threshold, but may not instruct multiple retransmissions of Msg.3 if this is not the case.

[0176] Whether to transmit multiple repetitions of Msg.3 retransmission may be indicated by one bit of information, or may be indicated by the number of repetitions. The correspondence between the value (code point) of the repetition indication and the number of repetitions may be specified in the specifications, or may be notified / set by broadcast / SIB / upper layer signaling, etc. For example, in the correspondence, the value 00 may correspond to the number of repetitions 1 (transmission in 1 slot), and the value 01 may correspond to the number of repetitions 2 (transmission in 2 slots).

[0177] If the UE is not instructed whether to transmit multiple repetitions of Msg.3 (the number of repetitions), the UE may not transmit multiple repetitions of Msg.3, may use the number of repetitions of the initial Msg.3 transmission as the number of repetitions of Msg.3, may use the number of repetitions of the previous Msg.3 retransmission as the number of repetitions of Msg.3, or may use a specific number of repetitions (the number of repetitions specified in the specifications) as the number of repetitions of Msg.3.

[0178] Aspect 8-4 This aspect relates to a method for determining a beam for initial transmission / retransmission of Msg.3.

[0179] [Aspect 8-4-1] The beam for the initial transmission / retransmission of Msg.3 may be specified in the specifications, or may be notified / set by broadcast / SIB / higher layer signaling, etc.

[0180] [Aspect 8-4-2] The beam for the initial transmission / retransmission of Msg.3 may be indicated by at least one of Msg.2, Msg.3 RAR UL grant, and DCI scheduling the retransmission of Msg.3. The correspondence between the indication value (code point) and the beam ID (RS index) may be specified in the specifications, or may be notified / set by broadcast / SIB / higher layer signaling, etc.

[0181] The assignment of beam IDs and the assignment of the number of repetitions may be indicated by common instruction information (field / bit). For example, as in the example of Fig. 23A, when the value of the 2-bit instruction information is 00 to 01, the number of repetitions may be 2, and when the value of the instruction information is 10 to 11, the number of repetitions may be 4. A beam ID of the number of repetitions (beam ID for each repetition) may be associated with each value of the instruction information.

[0182] The assignment of beam IDs and the assignment of the number of repetitions may be indicated by independent instruction information (fields / bits). For example, as in the example of FIG. 23B, each value of the 2-bit first instruction information is associated with four beam IDs, and the number of repetitions may be indicated / set by separate second instruction information or may be specified in the specifications. When the number of repetitions is 2, the first two beam IDs of the four beam IDs indicated by the first instruction information are used for the first repetition and the second repetition, respectively.

[0183] [Aspect 8-4-3] The beam for the initial transmission / retransmission of Msg.3 may be determined by the UE. The beam for the initial transmission / retransmission of Msg.3 may be determined based on a rule or may depend on the UE implementation.

[0184] Aspect 8-5 This embodiment relates to the above-mentioned embodiment 8-4-1.

[0185] When a UE uses a wide beam (beam of the first SSB) and a narrow beam (beam narrower than the beam of the first SSB), the correspondence between the beam ID of the wide beam and the beam ID of the narrow beam may be specified in the specification, may be notified / set by broadcast / SIB / upper layer signaling, etc., or may be reported by the UE.

[0186] 24, spatial relation #1-1 includes spatial relations #2-1 to #2-4. For example, if spatial relation #1-1 is used for the initial transmission of Msg.3, spatial relations #2-1 to #2-4 may be used for the retransmission of Msg.3.

[0187] According to this embodiment, the performance of Msg.3 can be improved.

[0188] <Ninth embodiment> Regarding the relationship between the 2nd SSB and Msg.3.

[0189] The UE may receive / measure / detect the second SSB.

[0190] A UE that detects the first SSB may transmit Msg.1 (PRACH) in the PRACH occasion corresponding to the detected first SSB, receive an RAR in the RAR window corresponding to the first SSB, and transmit Msg.3 scheduled by the RAR UL grant in the RAR. The UE may only perform initial access operation based on the first SSB if it is capable of doing so.

[0191] If a specific number of Mg.3 transmission failures occur, either the following initial access actions 1 or 2 may be followed. The Mg.3 transmission failure may be due to scheduling of Mg.3 retransmission or failure to receive Mg.4 within a certain time. The specific number of failures may be specified in the specification or may be notified / set by broadcast / SIB / higher layer signaling, etc. The specific number of failures may be 1.

[0192] [Initial access behavior 1] The UE continues initial access based on the first SSB and uses the beam corresponding to the detected second SSB for Msg.3 retransmission. Here, the UE may transmit multiple repetitions of Msg.3 retransmission, as in the eighth embodiment. The UE continues initial access based on the first SSB and uses the beam corresponding to the detected second SSB for Msg.3 retransmission after a specific number of failed Msg.3 transmissions.

[0193] [Initial access behavior 2] The UE may terminate initial access based on the first SSB and initiate initial access based on the detected second SSB. The UE may transmit Msg. 1 in the PRACH occasion corresponding to the detected second SSB, receive an RAR in the RAR window corresponding to the detected second SSB, and transmit Msg. 3 scheduled by an RAR UL grant in the RAR. Here, the UE may use the beam corresponding to the detected second SSB to transmit Msg. 3.

[0194] The UE does not need to receive / measure / detect all of the second SSBs (it may receive / measure / detect some of the second SSBs). If the QCL relationship (inclusion relationship) between the first SSB index and the second SSB index is specified / configured, the UE may receive / measure / detect the second SSB index that corresponds to (is included in) the first SSB index. The UE may use the second SSB index that corresponds to (is included in) the first SSB index used in the beam for the initial transmission of Msg.3 for the beam for the retransmission of Msg.3.

[0195] In the eighth embodiment, the beams from Msg.2 onwards may be based on the detected second SSB or a second SSB corresponding to (included in) the detected first SSB.

[0196] The UE may perform initial access after receiving both the first and second SSBs. If the UE is capable of performing initial access based on the first SSB, it may perform initial access based only on the first SSB. This improves resource utilization efficiency by limiting Msg.2 beam sweep to a minimum number of UEs.

[0197] In the example of Figure 25, a UE detects a first SSB and multiple second SSBs, transmits Mg. 1 in the PRACH occasion corresponding to the detected first SSB, receives an RAR in the RAR window corresponding to the detected first SSB, and the initial transmission of Mg. 3 scheduled by the RAR UL grant within the RAR fails. The UE transmits multiple repetitions of Mg. 3 retransmissions. The multiple repetitions may correspond to multiple detected second SSBs, respectively. The multiple second SSBs may be associated with (or encompass) the detected first SSB.

[0198] According to this embodiment, the performance of the initial access / Msg.3 can be improved using the second SSB.

[0199] <Tenth embodiment> This relates to the beams used for SSB (1st SSB / 2nd SSB).

[0200] In NR, the SSB transmission period is 20 ms and the period for maintaining PBCH content is 80 ms.

[0201] Beam sweeping / beam cycling may be used within a specific period for at least some specific channels / signals (second signals) of the PSS / SSS / PBCH within the SSB. For example, a narrower beam (beam of the second SSB) than that of the first SSB may be used for this beam sweeping.

[0202] As in Figure 26, if the beam of SSB index #1 includes beams of SSB indexes #1-1 to #1-4, the UE may assume that it can receive narrow beams such as SSB indexes #1-1 to #1-4 even when using (assuming) a wide beam such as SSB index #1.

[0203] The UE may identify the time / frequency of the SSB using a wide beam such as SSB index #1, and then identify SSB indexes #1-1 to #1-4 using narrow beams such as SSB indexes #1-1 to #1-4.

[0204] For example, a wide beam (SSB index #1) may be used for PSS / SSS (first signal), and narrow beams (SSB indexes #1-1 to #1-4) may be used for PBCH-DMRS and PBCH (second signal).

[0205] As shown in Figure 27, a set of SSBs is transmitted every SSB transmission period (e.g., 20 ms), and the PSS / SSS in the SSB with SSB index #1 in each SSB transmission period is transmitted using the same beam (SSB index #1). This prevents a decrease in the accuracy of PSS / SSS detection.

[0206] In multiple SSB transmission periods (e.g., four SSB transmission periods) within a specific period (e.g., 80 ms), the PBCH-DMRS and PBCH within the SSB with SSB index #1 may be beam swept (transmitted using four beams with SSB indexes #1-1 to #1-4, respectively).

[0207] As shown in Figure 28, a set of SSBs is transmitted every SSB transmission period (e.g., 20 ms), and the PSS / SSS in the SSB with SSB index #1 in each SSB transmission period is transmitted using the same beam (SSB index #1). This prevents a decrease in the accuracy of PSS / SSS detection.

[0208] In the first SSB transmission period within a specific period (e.g., 100 ms), the PBCH-DMRS and PBCH in the SSB with SSB index #1 may be transmitted using the beam with SSB index #1. In the second and subsequent SSB transmission periods within the specific period (e.g., the second to fifth four SSB transmission periods), the PBCH-DMRS and PBCH in the SSB with SSB index #1 may be beam swept (transmitted using four beams with SSB indexes #1-1 to #1-4, respectively).

[0209] The UE may assume that at least some specific channels / signals of PSS / SSS / PBCH (PBCH-DMRS) in one SSB are not QCL related to other channels / signals.

[0210] As shown in FIG. 29A, the SSS and the PBCH may be transmitted in the same symbol, or as shown in FIG. 29B, the SSS and the PBCH may be transmitted in different symbols.

[0211] <<Aspect 10-1>> This aspect relates to the transmission of Msg.1 (PRACH) and the reception of Msg.2 PDCCH / RAR.

[0212] [Aspect 10-1-1] The UE may transmit Msg.1 (PRACH) using a wide beam such as SSB index #1 (a beam that includes beams with SSB indexes #1-1 to #1-4).

[0213] A PRACH occasion may correspond to a wide beam, such as SSB index #1. Based on reception / measurement / detection of an SSB of a wide beam, such as SSB index #1, the UE may select a PRACH occasion corresponding to that SSB and transmit a PRACH on the selected PRACH occasion. The number of PRACH occasions may be the number of SSBs of a wide beam, such as SSB index #1 (e.g., 64).

[0214] The UE may receive Msg.2 PDCCH / RAR using the beam of the SSB index (e.g., SSB index #1) notified using Msg.1.

[0215] [Aspect 10-1-2] The UE may transmit Msg.1 (PRACH) using narrow beams such as SSB indexes #1-1 to #1-4 (beams contained in the beam of SSB index #1).

[0216] A PRACH occasion may correspond to a narrow beam, such as SSB index #1-1 through #1-4. Based on reception / measurement / detection of an SSB of a narrow beam, such as SSB index #1-1 through #1-4, the UE may select a PRACH occasion corresponding to that SSB and transmit a PRACH on the selected PRACH occasion. The number of PRACH occasions may be the number of SSBs of a narrow beam, such as SSB index #1-1 through #1-4 (e.g., 64×4).

[0217] The UE may receive Msg.2 PDCCH / RAR using the beam of the SSB index (for example, any of SSB indexes #1-1 to #1-4) notified using Msg.1.

[0218] 《Aspect 10-2》 This aspect relates to the transmission of Msg.3.

[0219] [Aspect 10-2-1] The UE may transmit Msg.3 using a wide beam such as SSB index #1 (a beam that includes beams with SSB indexes #1-1 to #1-4).

[0220] The beam used for transmitting Msg.3 may be the beam notified by Msg.1 in aspect 10-1-1.

[0221] In aspect 10-1-2, the UE may include narrow beam information (indexes in FIG. 30A) such as SSB indexes #1-1 to #1-4 in Msg. 3. This allows the UE to use the narrow beam notified by Msg. 3 for transmission and reception after transmitting Msg. 3.

[0222] The UE may signal the narrow beam via other UL channels / UL signals instead of Msg.3.

[0223] After receiving a response to Msg.3 (e.g., Msg.4 PDCCH / PDSCH), the UE may use the narrow beam notified by Msg.3 as QCL information. In other words, the UE may use the narrow beam notified by Msg.3 as a QCL source in transmission and reception after receiving the response to Msg.3.

[0224] The fact that a channel / signal is SSB and QCL (is QCLed as SSB) may be interpreted as the SSB and QCL of the SSB index notified by MMsg.3.

[0225] [Aspect 10-2-2] The UE may transmit Msg.3 using narrow beams such as SSB indexes #1-1 to #1-4 (beams contained in the beam of SSB index #1).

[0226] In aspect 10-1-1, the UE may report information about a wide beam by Msg. 1 and include information about the narrow beams (indexes in FIG. 30B) associated with (contained in) that wide beam in Msg. 3. In this example, SSB index #x of the wide beam corresponds to SSB indexes #x-1 to #x-4 of the narrow beams.

[0227] The UE may signal the narrow beam via other UL channels / UL signals instead of Msg.3.

[0228] Aspect 10-3 The UE may not assume a QCL between the PSS / SSS and the PBCH in one SSB. The UE may not assume a QCL between multiple PBCHs corresponding to the same SSB index within a specific period.

[0229] In aspect 10-2, the UE may notify the narrow beam (PBCH beam, SSB index corresponding to the received PBCH beam) by Msg.3.

[0230] Before a certain timing (based on Msg.3 transmission, Msg.4 reception, or HARQ-ACK transmission for Msg.4), a channel / signal being SSB and QCL may mean that the channel / signal is PSS / SSS and QCL. After that timing, a channel / signal being SSB and QCL may mean that the channel / signal is PBCH / PBCH-DMRS and QCL.

[0231] Aspect 10-4 The UE may be notified of information (SSB index) about the narrow beam (beam of the PBCH / PBCH-DMRS) via the PBCH / PBCH-DMRS. In aspect 10-2-2, the UE may report information about this narrow beam by Msg.3.

[0232] [Aspect 10-4-1] The beam of the PBCH (narrow beam, SSB index #1-1 to #1-4) may be signaled in the PBCH by information outside the MIB (e.g., timing related bits).

[0233] For example, when the beam of Figure 27 mentioned above is used for PBCH, four different values ​​(SSB indexes #1-1 to #1-4) may be notified in the timing-related fields of four SSB transmission periods within a specific period, as in the example of Figure 31.

[0234] The SSB indexes #x-1 to #x-4 of the narrow beams corresponding to the SSB index #x of the wide beam (PSS / SSS beam) may be signaled in the PBCH by information outside the MIB (for example, timing related bits). This allows the size of the information to be reduced compared to aspect 10-4-1.

[0235] The beam cycle period of the PBCH (eg, a particular period, the number of SSB transmission periods used in the beam cycle, etc.) may be signaled by the MIB / SIB.

[0236] [Aspect 10-4-2] The PBCH beams (narrow beams, SSB indices #1-1 to #1-4) may be signaled by the PBCH-DMRS sequences. Within a specific period, the PBCH-DMRS sequences corresponding to the same wide beam (PSS / SSS beam) may be different for each narrow beam (SSB transmission period). In the PBCH-DMRS sequences, at least one of a time / frequency resource, a cyclic shift index, a comb index, and an orthogonal cover code (OCC) index may be associated with the narrow beam index.

[0237] The correspondence between the PBCH SSB index and the PBCH-DMRS sequence may be specified, broadcast, or configured by higher layer signaling. By receiving / confirming / detecting the PBCH-DMRS sequence, the UE can derive a narrow beam (SSB index #1-1 to #1-4) from the received PBCH-DMRS based on the correspondence.

[0238] For example, if the beam of Figure 27 mentioned above is used for the PBCH and the wide beam (PSS / SSS beam) is SSB index #x, the PBCH-DMRS sequences for four SSB transmission periods within a particular period may be associated with four different values ​​(SSB indexes #x-1 to #x-4), as in the example of Figure 32.

[0239] 33, the cyclic shift of the PBCH-DMRS sequence for four SSB transmission periods within a specific period may be associated with four different values ​​(cyclic shift indexes and PBCH-DMRS sequence indexes corresponding to SSB indexes #x-1 to #x-4). The four different values ​​of the cyclic shift index m_CS may be 0, 3, 6, and 9.

[0240] [Aspect 10-4-3] The beams of the PBCH (narrow beams, SSB indexes #1-1 to #1-4) may be determined by rules using the time domain resources of the SSBs. For example, the rules may determine the SSB index from the SFN and the time position within the frame.

[0241] For example, if the beam in Figure 27 described above is used for the PBCH and the wide beam (PSS / SSS beam) is SSB index #x, multiple SSBs (e.g., 64 SSBs) within the SSB set for each SSB transmission period may be indexed, and multiple SSB sets (e.g., 4 SSB sets) from a reference point (e.g., the starting point of a frame, a specific period (e.g., 4 SSB transmission periods), a specific number of SSB transmission periods (e.g., 4), etc.) may be indexed, as in the example of Figure 34. The SSB index #xi of the PBCH beam may be modulated (e.g., mod 4) for each specific number of SSB transmission periods.

[0242] Aspect 10-5 When the UE uses the SSB index in a procedure (transmission / reception of a certain channel / signal) after notifying the SSB index, the fact that a certain channel / signal is QCL'd with the SSB having that SSB index may follow at least one of the following interpretations 1 and 2. [Interpretation 1] The UE uses the PSS / SSS of its SSB as the QCL source for its channel / signal. [Interpretation 2] The UE uses the PBCH-DMRS of its SSB as the QCL source for its channel / signal.

[0243] The UE may follow either of the following QCL application methods 1 and 2.

[0244] [QCL application method 1] As described in aspect 10-3, the UE may use interpretation 1 before a certain timing (based on transmission of Msg.3, reception of Mg.4, or transmission of HARQ-ACK for Msg.4) and may use interpretation 2 after that timing. The certain timing may be after a specific time (a specific number of symbols / a specific number of slots) has elapsed since transmission of Msg.3, reception of Mg.4, or transmission of HARQ-ACK for Msg.4.

[0245] [QCL application method 2] For each channel / RS to which the QCL is applied (target), whether interpretation 1 or 2 is to be used may be specified in the specification, may be broadcast, or may be set / instructed.

[0246] Either interpretation 1 or 2 may be set / instructed together with beam instructions such as TCI status / QCL information.

[0247] For example, for UE-specific channels / RSs, interpretation 2 may be used since narrow beams are preferred. For example, for UE-common channels / RSs, interpretation 1 may be used since repeated transmission of many beams would be overhead.

[0248] According to this embodiment, the UE can properly determine the beam to be used for the SSB / channel / signal.

[0249] <Eleventh embodiment> Repeat transmission may be notified / configured by broadcast / higher layer signaling. The notified / configured UE may apply repeat transmission to a specific type of channel / RS (Figure 35). The same repetition number may be applied to all notified / configured UEs.

[0250] The specific type of channel / RS may be multiple types of DL / UL channels / RS, or may be all DL / UL channels / RS.

[0251] For a particular type of channel / RS, one repetition number (aggregation factor) may be set.

[0252] A plurality of repetition numbers may be set for a plurality of types of channels / RSs, or a repetition number may be set for each type of channel / RS.

[0253] The repetition number may be specified in the specification, may be signaled / configured by broadcast / MIB / SIB, may be signaled / configured by UE-specific higher layer control information (RRC IE), or may be based on a value reported by UE capability signaling. For example, a UE with poor transmission / reception performance may use a large repetition number, and a UE with better performance may use a small repetition number.

[0254] The method for setting the number of repetitions may follow the method described later in aspect 2-2.

[0255] Several patterns of repetition numbers may be specified / configured. One of the patterns may be indicated by broadcast / upper layer signaling / MAC CE / physical layer control information. The example in FIG. 36A shows a case where one repetition number is configured / instructed for multiple types of channels / RSs. When configurations #1 to #4 are configured and one of configurations #1 to #4 is indicated, the UE applies the repetition number corresponding to the indicated configuration to multiple types of channels / RSs. The example in FIG. 36B shows a case where one repetition number is configured / instructed for each type of channel / RS. When configurations #1 to #4 are configured and one of configurations #1 to #4 is indicated, the UE applies the repetition number corresponding to the channel / RS (PUSCH / PUCCH / PDSCH) from the indicated configuration to that channel / RS.

[0256] According to this embodiment, coverage can be improved by repeated transmissions.

[0257] <Twelfth embodiment> Repeated transmission may be notified / configured by broadcast / higher layer signaling, and the notified / configured UE may apply repeated transmission to specific types of channels / RSs as needed (depending on conditions) (Figure 37).

[0258] The specific type of channel / RS may be multiple types of DL / UL channels / RS, or may be all DL / UL channels / RS.

[0259] If the application conditions are met, the UE may apply repeated transmission to a particular type of channel / RS.

[0260] The number of repetitions may be set for each type of channel / RS, or may be set for multiple types of DL / UL channels / RS.

[0261] The number of repetitions may be notified / set by broadcast / MIB / SIB, or may be notified / set by UE-specific upper layer control information (RRC IE).

[0262] The number of iterations may be determined based on a decision rule.

[0263] If the UE successfully detects PSS / SSS (PSS / SSS received power is above the threshold) but fails to read the MIB, the decision rule may determine the number of repetitions based on the number of failures in MIB reading. For example, if the number of failures is 0, the number of repetitions is 1 (no repeated transmissions), and if the number of failures is 4, the number of repetitions is 4.

[0264] The decision rule may determine the number of repetitions based on the number of failed transmissions of Msg. 3. For example, the number of repetitions for the first transmission of Msg. 3 is 1, the number of repetitions for the first retransmission of Msg. 3 is 2, and the number of repetitions for the second retransmission of Msg. 3 is 3.

[0265] The correspondence between the number of MIB read failures, the number of Msg.3 transmission failures, etc. and the number of repetitions may be specified in the specifications, may be set by higher layer signaling, or may be reported by UE capability signaling.

[0266] The question is when the determined number of repetitions will be applied.

[0267] The UE may apply the determined repetition number to a specific type of channel / RS immediately after the applicable condition is met. The UE may apply the repetition number to a specific type of channel / RS that is triggered / scheduled after the applicable condition is met. The UE may apply the repetition number to a specific type of channel / RS that is transmitted / received after the applicable condition is met.

[0268] The UE may apply the determined repetition number to a specific type of channel / RS after a waiting time (e.g., X symbols / X slots / Y [ms]) has elapsed since the application condition was satisfied. The UE may apply the repetition number to a specific type of channel / RS that is triggered / scheduled after the waiting time has elapsed since the application condition was satisfied. The UE may apply the repetition number to a specific type of channel / RS that is transmitted / received after the waiting time has elapsed since the application condition was satisfied.

[0269] The waiting time may be specified in a specification, configured by higher layer signaling, or reported by UE capability signaling.

[0270] The UE may explicitly or implicitly notify the base station of repeated transmission after the applicable conditions are met, and apply the determined number of repetitions to a specific type of channel / RS based on the notification. If the UE determines that repeated transmission is necessary, repeated transmission in the uplink is possible. If the UE notifies the base station that repeated transmission is necessary, repeated transmission in the downlink is also possible.

[0271] The UE may explicitly send a repeat transmission request / indication / notification in the first UL transmission after the applicable conditions are met. The UE may also implicitly send a repeat transmission request / indication / notification by performing a repeat transmission in the first UL transmission after the applicable conditions are met.

[0272] 《Aspect 12-1》 The UE may determine the repeat transmission / number of repeats. The applicable condition may be at least one of the following conditions, or may be AND / OR of multiple conditions among the following conditions: The received power / quality of a specific SSB is below a threshold (for example, the specific SSB may be the SSB corresponding to the highest received power / quality among 65 SSBs). The UE fails to transmit Mg.1 (PRACH) within a specific period (time) (the UE does not receive Mg.2 within a specific period (time)). · The UE fails to receive Mg.2 (PDCCH / RAR) within a specific period (time) (the UE does not receive Mg.2 (PDCCH / RAR) within a specific period (time)). The UE fails to transmit Mg.3 (PUSCH scheduled by the RAR UL grant) within a specific period (time) (the UE does not receive Mg.4 within a specific period (time), or the UE is instructed to retransmit Mg.3). · The UE fails to receive Mg.4 within a specific period (time) (the UE does not receive Mg.4 within a specific period (time)). The UE fails to transmit Mg.4 HARQ-ACK within a specific period (time) (the UE is instructed to receive Mg.4 retransmission within a specific period (time)). The UE decides based on its implementation (the UE decides to repeat transmission of Msg.1 / Msg.3 / Msg.4 HARQ-ACK based on SSB reception, etc.). A UE that has performed repeated transmission of Msg.1 / Msg.3 / Msg.4 HARQ-ACK may apply repeated transmission to specific types of channels / RSs in subsequent operations after the initial access procedure / RRC connection establishment. The UE may also transmit a request / desired number of repetitions to the base station. The UE fails to transmit Mg.A (PRACH / PUSCH) within a specific period (time) (the UE does not receive Mg.B within a specific period (time), or Mg.B schedules the transmission of Mg.3 (fallback indication)). · The UE fails to receive Msg.B (PDCCH / PDSCH) within a specific period (time) (the UE does not receive Msg.B (PDCCH / PDSCH) within a specific period (time)). · The UE successfully reads the MIB, but fails to receive at least one of the SIB1 PDSCH and the PDCCH (CORESET#0 / Search Space#0) that schedules it.

[0273] As shown in Figure 38A, if the application conditions are not met (if the initial transmission of Msg.3 is successful), the UE may not apply repeated transmission to a specific type of channel / RS thereafter (a repetition count of 1 may be applied).

[0274] As shown in Figure 38B, if the application condition is met (if the initial transmission of Msg.3 fails), the UE may apply repeated transmission (may apply a repetition number greater than 1) to subsequent specific types of channels / RSs (e.g., Msg.3 retransmissions). The UE may use different beams for multiple repetitions (may use beam sweeping), or may use the same beam for multiple repetitions.

[0275] The relationship between the application conditions and the number of repetitions will be explained below.

[0276] [Aspect 12-1-A] The correspondence between the application condition and the repetition number may be specified in the specification, or may be notified / set by broadcast / higher layer signaling. The UE may use the correspondence to determine the repetition number corresponding to the application condition and apply the repetition number to a specific type of channel / RS.

[0277] 39A and 39B, the application conditions are defined by the range of SSB RSRP value P. The boundary values ​​P_0, P_1, and P_2 may be specified in the specification or may be notified / set by broadcast / higher layer signaling.

[0278] In the example of Figure 39A, the number of repetitions is defined for one or more specific types of channels / RSs. In the example of Figure 39B, the number of repetitions is defined for each type of channel / RS (PUSCH / PUCCH / PDSCH). Since the coverage differs for each channel / RS, the required number of repetitions may also differ. For example, the DL reception (transmission) power is higher than the UL reception (transmission) power, and the larger the payload size, the smaller the coverage. The type of channel / RS may be the type of message / content. The type of message / content may be Msg.2 / 3 / 4, etc.

[0279] Example 12-1 may be applied before the RRC connection is established, and the repetition number may be set by an RRC IE after the RRC connection is established.

[0280] [Aspect 12-1-B] Multiple configurations / candidates for the number of repetitions requested / reported by UL transmission (e.g., Msg.3) may be specified in the specifications, or may be notified / configured by broadcast / higher layer signaling. The UE may determine the number of repetitions from the multiple configurations. The UE may request / report the determined number of repetitions by Msg.3 and apply it to a specific type of channel / RS after acknowledging receipt of Msg.3 (reception of Mg.4 PDCCH or Mg.4 (PDSCH)).

[0281] In the example of FIG. 40A, multiple settings / candidates for the number of repetitions for one or more specific types of channels / RSs are defined / set. In the example of FIG. 40B, multiple settings / candidates for the number of repetitions are defined / set for each type of channel / RS (PUSCH / PUCCH / PDSCH). Since coverage differs for each channel / RS, the required number of repetitions may also differ. For example, DL reception (transmission) power is higher than UL reception (transmission) power, and the larger the payload size, the smaller the coverage. The type of channel / RS may be the type of message / content. The type of message / content may be Msg.2 / 3 / 4, etc.

[0282] Example 12-1 may be applied before the RRC connection is established, and the repetition number may be set by an RRC IE after the RRC connection is established.

[0283] 《Aspect 12-2》 The base station (network) may determine the repeat transmission / number of repeats. The UE may be instructed / configured to perform the repeat transmission by at least one of Msg.2 PDCCH / RAR, Msg.4, Msg.B PDCCH / PDSCH, and higher layer signaling.

[0284] Multiple configurations / candidates of the repetition number indicated / set by DL transmission (at least one of Msg.2 PDCCH / RAR, Msg.4, Msg.B PDCCH / PDSCH, and higher layer signaling) may be specified in the specification or may be notified / set by broadcast / higher layer signaling. The base station may notify / indicate / set one of multiple configurations of the repetition number by DL transmission. The UE may apply the notified repetition number to a specific type of channel / RS.

[0285] In the example of FIG. 41A, multiple settings / candidates for the number of repetitions for one or more specific types of channels / RSs are defined / configured. In the example of FIG. 41B, multiple settings / candidates for the number of repetitions are defined / configured for each type of channel / RS (PUSCH / PUCCH / PDSCH). Since coverage differs for each channel / RS, the required number of repetitions may also differ. For example, DL reception (transmission) power is higher than UL reception (transmission) power, and the larger the payload size, the smaller the coverage. The type of channel / RS may be the type of message / content. The type of message / content may be Msg.2 / 3 / 4, etc.

[0286] According to this embodiment, the UE can appropriately apply repeated transmission.

[0287] <Thirteenth embodiment> Coverage may be expanded by repeating SSB transmission. Channels / RS other than SSB (e.g., UE-specific channels / RS) may use narrower beams than SSB to expand coverage. Channels / RS other than SSB may not use repeat transmission whenever possible.

[0288] The repeated transmission of SSBs transmitted periodically has little impact on system overhead, whereas the repeated transmission of UE-specific channels / RSs has a large impact on system overhead.

[0289] As in the example of FIG. 42A, signals using a wide beam (e.g., the wide beam SSB, the first SSB) may be combined and received to expand coverage. A UE may obtain combining gain by combining and receiving a specific number (e.g., four) of SSBs. As in the example of FIG. 42B, signals using a narrow beam (e.g., the narrow beam SSB, the second SSB) may be narrowed to expand coverage. In the examples of FIGS. 42A and 42B, one wide beam corresponds to (includes) four narrow beams. The narrow beams are beam swept, and a different beam (SSB index #1 to #4) is used for each period. In this example, the narrow beam second SSB is transmitted in a different frame / slot from the wide beam first SSB, but they may also be transmitted in the same frame / slot. As in the tenth embodiment, the PSS / SSS and the PBCH / PBCH-DMRS may be transmitted using different beams within one SSB.

[0290] If the application conditions in the twelfth embodiment are met, the UE may request a narrow beam (e.g., the second SSB) as a QCL source for a specific type of channel / RS. The UE may follow either of the following beam application operations 1 and 2.

[0291] [Beam application action 1] If the application condition is met (for example, if the received power / quality of the SSB is equal to or less than a threshold), the UE may request / report repeated transmission as in aspect 12-1-B and may apply a narrow beam to the QCL source of a specific type of channel / RS. The UE may determine the number of repetitions and also select / determine the beam to be applied to the repetitions. A wide beam (first SSB) may be applied to channels / RSs to which repeated transmission is not applied. A narrow beam (second SSB) may be applied to channels / RSs to which repeated transmission is applied. The number of repetitions of channels / RSs using narrow beams may be smaller than the number of repetitions of channels / RSs using wide beams.

[0292] [Beam application action 2] If the application conditions are met (e.g., if the received power / quality of the SSB is below a threshold), the UE may not request / report repeated transmission as in aspect 12-1-B, but may apply a narrow beam to the QCL source of a particular type of channel / RS.

[0293] According to beam application operations 1 and 2, the resources required for repeated transmission can be reduced, and resource utilization efficiency can be improved.

[0294] The narrow beam may be one of multiple secondary SSBs associated with (contained within) the received primary SSB. The narrow beam selection method may be specified in the specification or signaled / configured via PBCH / SIB1 / broadcast / higher layer signaling.

[0295] The channels / RS to which the narrow beam is applied may be all the channels / RS.

[0296] The channel / RS to which the narrow beam is applied may be a specific type of channel / RS. The specific type may be an RS, a data channel, a control channel, or a channel having a payload size equal to or larger than a certain value. For channels / RS other than the specific type, repeated transmission may be applied, or neither repeated transmission nor narrow beam may be applied.

[0297] Figure 43A is a diagram illustrating an example of the eleventh and twelfth embodiments. If the applicable condition is met (the received power / quality of the detected SSB is equal to or less than a threshold), the UE may transmit a PRACH in the PRACH occasion corresponding to the SSB, receive Msg. 2 in the RAR window, and transmit multiple repetitions of Msg. 3 using a wide beam. Different wide beams may be used for the multiple repetitions. The SSB may be a first SSB. Different wide beams may be associated with different first SSBs.

[0298] Figure 43B shows an example of beam application operation 1. If the application condition is met (the received power / quality of the detected SSB is equal to or less than a threshold), the UE may transmit a PRACH in the PRACH occasion corresponding to the SSB, receive Msg. 2 in the RAR window, and transmit multiple repetitions of Msg. 3 using a narrow beam. Different narrow beams may be used for the multiple repetitions. The SSB may be a first SSB. A different narrow beam may be associated with a different second SSB associated with the first SSB.

[0299] Figure 43C shows an example of beam application operation 2. If the application condition is met (the received power / quality of the detected SSB is equal to or less than a threshold), the UE may transmit a PRACH in the PRACH occasion corresponding to the SSB, receive Msg. 2 in the RAR window, and transmit Msg. 3 (non-repeated transmission) using a narrow beam. The SSB may be a first SSB. The narrow beam may be associated with one of multiple second SSBs associated with the first SSB.

[0300] In the embodiments 12-1-A, 12-1-B, and 12-2, in addition to the number of repetitions, whether to use a wide beam or a narrow beam may be set. For example, in the example of Fig. 44A, the number of repetitions and whether to use a wide beam or a narrow beam may be associated with each setting in Fig. 14A of the embodiment 12-2. For example, in the example of Fig. 44B, the number of repetitions and whether to use a wide beam or a narrow beam may be associated with each setting in Fig. 14B of the embodiment 12-2.

[0301] <Other embodiments> 《UE Capabilities / Upper Layer Parameters》 In each embodiment, a higher layer parameter (RRC information element) / UE capability corresponding to at least one function (feature) may be defined. The UE capability may indicate whether the function is supported.

[0302] A UE for which a higher layer parameter corresponding to the function is configured may perform the function. Alternatively, it may be specified that "a UE for which a higher layer parameter corresponding to the function is not configured does not perform the function (for example, applies the operation of Rel. 15 / 16)."

[0303] A UE that reports a UE capability indicating that it supports the function may perform the function. It may also be specified that "a UE that does not report a UE capability indicating that it supports the function shall not perform the function (e.g., apply the behavior of Rel. 15 / 16)."

[0304] If the UE reports a UE capability indicating that it supports the function and the corresponding upper layer parameter is configured, the UE may perform the function. It may also be specified that "if the UE does not report a UE capability indicating that it supports the function or if the corresponding upper layer parameter is not configured, the UE shall not perform the function (e.g., apply the behavior of Rel. 15 / 16)."

[0305] The UE capabilities may indicate whether or not the second SSB is supported.

[0306] The UE capability may indicate whether it supports one QCL source / RS index being associated with (encompassing) multiple QCL source / RS indices.

[0307] The above UE capabilities / upper layer parameters allow the UE to achieve the above functions while maintaining compatibility with existing specifications.

[0308] (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.

[0309] 45 is a diagram illustrating an example of a schematic configuration of a wireless communication system according to an embodiment. The wireless communication 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).

[0310] 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.

[0311] In EN-DC, the LTE (E-UTRA) base station (eNB) is the master node (MN), and the NR base station (gNB) is the 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.

[0312] 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 the SN are NR base stations (gNBs) (NR-NR Dual Connectivity (NN-DC))).

[0313] 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 locations and numbers of the cells and user terminals 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 base station 10.

[0314] 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 (CC) and dual connectivity (DC).

[0315] 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 above 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 be a frequency band higher than FR2.

[0316] 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.

[0317] The multiple base stations 10 may be connected by wire (for example, optical fiber conforming to the Common Public Radio Interface (CPRI), an X2 interface, or the like) or wirelessly (for example, 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.

[0318] 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.

[0319] The user terminal 20 may be a terminal compatible with at least one of communication methods such as LTE, LTE-A, and 5G.

[0320] An Orthogonal Frequency Division Multiplexing (OFDM)-based radio access scheme may be used in the radio 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).

[0321] The radio access scheme may also be called a waveform. Note that in the wireless communication system 1, other radio access schemes (for example, other single-carrier transmission schemes, other multi-carrier transmission schemes) may be used as the UL and DL radio access schemes.

[0322] 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.

[0323] 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)), etc. may be used as an uplink channel.

[0324] The PDSCH transmits user data, higher layer control information, System Information Block (SIB), etc. The PUSCH may transmit user data, higher layer control information, etc. Furthermore, the PBCH may transmit Master Information Block (MIB).

[0325] 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.

[0326] 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 an UL grant, a UL DCI, etc. Note that the PDSCH may be interpreted as DL data, and the PUSCH may be interpreted as UL data.

[0327] A control resource set (CORESET) and a search space may be used to detect the PDCCH. The CORESET corresponds to resources to search 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 a CORESET associated with a certain search space based on the search space configuration.

[0328] One search space may correspond to PDCCH candidates corresponding to one or more aggregation levels. One or more search spaces may be called a search space set. Note that the terms "search space," "search space set," "search space setting," "search space set setting," "CORESET," "CORESET setting," etc. in the present disclosure may be read interchangeably.

[0329] The PUCCH may transmit uplink control information (UCI) including at least one of channel state information (CSI), acknowledgement 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.

[0330] 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.

[0331] 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, 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 as DL-RS.

[0332] 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 the SS (PSS, SSS) and the PBCH (and 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 reference signals.

[0333] Furthermore, in the wireless communication system 1, a sounding reference signal (SRS), a demodulation reference signal (DMRS), etc. 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).

[0334] (base station) 46 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.

[0335] 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.

[0336] 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.

[0337] 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 to be transmitted as signals, control information, sequences, etc., 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.

[0338] 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.

[0339] The transmitting / receiving unit 120 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 1211 and an RF unit 122. The receiving unit may be composed of a reception processing unit 1212, an RF unit 122, and a measurement unit 123.

[0340] 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 pertains, such as an array antenna.

[0341] 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.

[0342] The transceiver 120 may form at least one of a transmission beam and a reception beam using digital beamforming (for example, precoding), analog beamforming (for example, phase rotation), or the like.

[0343] The transceiver 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.

[0344] The transceiver 120 (transmission processor 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.

[0345] The transmitting / receiving unit 120 (RF unit 122) may perform modulation to a radio frequency band, filtering, amplification, etc. on the baseband signal, and transmit the radio frequency band signal via the transmitting / receiving antenna .

[0346] On the other hand, the transmitting / receiving unit 120 (RF unit 122) may perform amplification, filtering, demodulation to a baseband signal, etc. on the radio frequency band signal received by the transmitting / receiving antenna .

[0347] 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.

[0348] 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.

[0349] The transmission path interface 140 may transmit and receive signals (backhaul signaling) between devices included in the core network 30, other base stations 10, etc., and may acquire and transmit user data (user plane data), control plane data, etc. for the user terminal 20.

[0350] 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.

[0351] The transceiver 120 may transmit a first number of first synchronization signal blocks and a second number of second synchronization signal blocks, and the controller 110 may control initial access based on at least one of the first number of first synchronization signal blocks and the second number of second synchronization signal blocks.

[0352] The transmitter / receiver 120 may transmit the first synchronization signal block and the second synchronization signal block, and the controller 110 may control reception of the signal based on the second synchronization signal block based on the reception result of the first synchronization signal block.

[0353] The transceiver 120 may transmit a first synchronization signal block and a plurality of second synchronization signal blocks, and the controller 110 may control the transmission assuming that the plurality of second synchronization signal blocks are quasi-colocated (QCL) with the first synchronization signal block.

[0354] The transceiver 120 may transmit a primary synchronization signal block. If reception of the primary synchronization signal block fails, the controller 110 may control reception of a preamble using a random access occasion for reporting the failure.

[0355] The transceiver 120 may receive a message in the random access procedure on the physical uplink shared channel. The controller 110 may control multiple repetitions of at least one of transmitting a downlink channel that schedules the physical uplink shared channel and receiving the physical uplink shared channel.

[0356] The transceiver 120 may transmit a synchronization signal block including a first signal and a second signal. The controller 110 may control the transmission of the synchronization signal block by assuming that a first beam used in the first signal is different from a second beam used in the second signal.

[0357] The transceiver 120 may transmit a repetition instruction for a plurality of types of signals, and the controller 110 may apply the repetition to the plurality of types of signals based on the instruction.

[0358] (user terminal) 47 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 transmitting / receiving antenna 230. Note that the user terminal 20 may include one or more of each of the control unit 210, the transceiver unit 220, and the transmitting / receiving antenna 230.

[0359] Note that this example mainly shows functional blocks of the characteristic parts of the present embodiment, 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.

[0360] 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, and the like that are explained based on common understanding in the technical field to which the present disclosure relates.

[0361] The control unit 210 may control signal generation, mapping, etc. The control unit 210 may also 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.

[0362] 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 from 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.

[0363] 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.

[0364] The transmitting / receiving antenna 230 can be configured as an antenna described based on common understanding in the technical field to which the present disclosure pertains, such as an array antenna.

[0365] 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.

[0366] The transceiver 220 may form at least one of a transmission beam and a reception beam using digital beamforming (for example, precoding), analog beamforming (for example, phase rotation), or the like.

[0367] The transceiver 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.

[0368] The transceiver 220 (transmission processor 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.

[0369] 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 when transform precoding is not enabled, the transceiver unit 220 may not perform DFT processing as the transmission processing.

[0370] The transmitting / receiving unit 220 (RF unit 222) may perform modulation to a radio frequency band, filtering, amplification, etc. on the baseband signal, and transmit the radio frequency band signal via the transmitting / receiving antenna 230.

[0371] On the other hand, the transmitting / receiving unit 220 (RF unit 222) may perform amplification, filtering, demodulation to a baseband signal, etc. on the radio frequency band signal received by the transmitting / receiving antenna 230.

[0372] The transceiver 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 to acquire user data, etc.

[0373] The transceiver 220 (measurement unit 223) may perform measurements on the received signal. For example, the measurement unit 223 may perform RRM measurement, CSI measurement, 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.

[0374] The transmitting section and receiving section of the user terminal 20 in the present disclosure may be configured by at least one of the transmitting / receiving section 220 and the transmitting / receiving antenna 230.

[0375] The transceiver 220 may receive at least one of a first number of first synchronization signal blocks and a second number of second synchronization signal blocks, and the controller 210 may control initial access based on the synchronization signal blocks.

[0376] The second number may be greater than the first number.

[0377] The transmission period of the second synchronization signal block may be different from the transmission period of the first synchronization signal block.

[0378] The second synchronization signal block may be transmitted aperiodically.

[0379] The transceiver 220 may attempt to receive the first synchronization signal block, and the controller 210 may control the reception of the second synchronization signal block based on the reception result of the first synchronization signal block.

[0380] When the first synchronization signal block is received, the control unit may control transmission of a first preamble using a first random access channel occasion corresponding to the first synchronization signal block.

[0381] When the second synchronization signal block is received, the control unit may control transmission of a second preamble using a second random access channel occasion corresponding to the second synchronization signal block.

[0382] If reception of the first synchronization signal block fails, the control unit may control reception of the second synchronization signal block.

[0383] The transceiver 220 may receive at least one synchronization signal block from the first synchronization signal block and the plurality of second synchronization signal blocks. The controller 210 may control reception by assuming that the plurality of second synchronization signal blocks are quasi-colocated (QCL) with the first synchronization signal block.

[0384] When a first downlink demodulation reference signal is QCL'd with the first synchronization signal block and a second downlink demodulation reference signal is QCL'd with one of the plurality of second synchronization signal blocks, the control unit may control reception assuming that the second demodulation reference signal is not QCL'd with the first demodulation reference signal.

[0385] When a first downlink demodulation reference signal is QCL'd with the first synchronization signal block and a second downlink demodulation reference signal is QCL'd with one of the plurality of second synchronization signal blocks, the control unit may control reception by assuming that the second demodulation reference signal is QCL'd with the first demodulation reference signal.

[0386] When a preamble is transmitted in a random access channel occasion corresponding to the synchronization signal block, the control unit may control reception by assuming that a third demodulation reference signal of the downlink is QCL'd with the synchronization signal block.

[0387] The transceiver 220 may attempt to receive the primary synchronization signal block. If reception of the primary synchronization signal block fails, the controller 210 may control transmission of a preamble using a random access occasion for reporting the failure.

[0388] If reception of the first synchronization signal block fails, the receiver may attempt to receive a second synchronization signal block.

[0389] If reception of the first synchronization signal block fails, after transmitting the preamble, the receiver may attempt to receive the second synchronization signal block.

[0390] If reception of the first synchronization signal block fails and reception of the second synchronization signal block is successful, the control unit may control transmission of the preamble.

[0391] The transceiver 220 may transmit a message in the random access procedure on the physical uplink shared channel. The controller 210 may control multiple repetitions of at least one of receiving a downlink channel that schedules the physical uplink shared channel and transmitting the physical uplink shared channel.

[0392] The control unit may use a plurality of beams for each of the plurality of repetitions.

[0393] If the initial transmission of the message fails, the controller may control the multiple repetitions of transmission of the physical uplink shared channel.

[0394] The random access procedure may be based on a first synchronization signal block, and the message retransmission may be based on a second synchronization signal block.

[0395] The transceiver 220 may receive a synchronization signal block including a first signal and a second signal. The controller 210 may control reception of the synchronization signal block by assuming that a first beam used in the first signal is different from a second beam used in the second signal.

[0396] The first signal may correspond to a first synchronization signal block index, the second signal may correspond to a second synchronization signal block index, and the first synchronization signal block index may be associated with a plurality of second synchronization signal block indexes.

[0397] The first synchronization signal block index may be constant for each period, and the second synchronization signal block index may be variable for each period.

[0398] The first signal may be a synchronization signal and the second signal may be a physical broadcast channel.

[0399] The transceiver 220 may receive an instruction to repeat the process for a plurality of types of signals, and the controller 210 may apply the repetition process to the plurality of types of signals based on the instruction.

[0400] If an application condition is satisfied, the control unit may apply the repetition to the plurality of types of signals.

[0401] The instruction may include a plurality of repetition numbers, and the control unit may apply one of the plurality of repetition numbers to at least one of the plurality of types of signals.

[0402] The control unit may apply a beam corresponding to a second synchronization signal block to the repetition in a random access procedure based on a first synchronization signal block.

[0403] (Hardware configuration) 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 also be realized by combining the single device or multiple devices with software.

[0404] 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 mentioned above, the implementation method of each is not particularly limited.

[0405] 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. 48 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.

[0406] In this disclosure, terms such as apparatus, circuit, device, section, unit, etc. may be read 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.

[0407] 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.

[0408] Each function in the base station 10 and the user terminal 20 is realized, for example, by loading predetermined 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.

[0409] 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), transmission / reception unit 120 (220), etc. may be realized by the processor 1001.

[0410] 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 realized by a control program stored in the memory 1002 and running on the processor 1001, and the other functional blocks may be realized in a similar manner.

[0411] The memory 1002 is a computer-readable recording medium and may be configured by at least one of, for example, a read-only memory (ROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a random access memory (RAM), or other suitable storage medium. The memory 1002 may also be referred to as a register, a cache, a main memory, or the like. The memory 1002 may store executable programs (program codes), software modules, and the like for implementing a wireless communication method according to an embodiment of the present disclosure.

[0412] Storage 1003 is a computer-readable recording medium and may be constituted by 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, stick, key drive), a magnetic stripe, a database, a server, or other suitable storage medium. Storage 1003 may also be referred to as a secondary storage device.

[0413] 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.

[0414] The input device 1005 is an input device (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that receives input from the outside. The output device 1006 is an output device (for example, a display, a speaker, a light emitting diode (LED) lamp, etc.) that outputs to the outside. The input device 1005 and the output device 1006 may be integrated into one device (for example, a touch panel).

[0415] 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.

[0416] 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 such hardware. For example, the processor 1001 may be implemented using at least one of these pieces of hardware.

[0417] (Variation) Note that terms explained 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.

[0418] 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.

[0419] 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, a subcarrier spacing (SCS), a bandwidth, a symbol length, a cyclic prefix length, a transmission time interval (TTI), the number of symbols per TTI, a radio frame structure, a specific filtering process performed by a transceiver in the frequency domain, and a specific windowing process performed by a transceiver in the time domain.

[0420] A slot may be composed of one or more symbols in the time domain (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol or a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol), and may be a time unit based on numerology.

[0421] 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.

[0422] 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.

[0423] 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 a subframe and a 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.

[0424] 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. However, the definition of TTI is not limited to this.

[0425] 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.

[0426] 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.

[0427] 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.

[0428] 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 equal to or greater than 1 ms.

[0429] 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 also be determined based on numerology.

[0430] 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. One TTI, one subframe, etc. may each be composed of one or more resource blocks.

[0431] Note that one or more RBs may also be called a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, etc.

[0432] 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.

[0433] A Bandwidth Part (BWP), which may also be referred to as a fractional 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 given BWP and numbered within that BWP.

[0434] The BWP may include an UL BWP (a BWP for UL) and a DL BWP (a BWP for DL). One or more BWPs may be configured for a UE within one carrier.

[0435] 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."

[0436] 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.

[0437] 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.

[0438] 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.

[0439] 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.

[0440] 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.

[0441] 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.

[0442] Notification of information is not limited to the aspects / embodiments described in the present disclosure, and may be performed using other methods. For example, 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.

[0443] Note that the physical layer signaling may be called 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 called 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).

[0444] 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).

[0445] 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).

[0446] 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.

[0447] 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), then these wired and / or wireless technologies are included within the definition of transmission media.

[0448] 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).

[0449] In the present 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," "antenna port group," "layer," "number of layers," "rank," "resource," "resource set," "resource group," "beam," "beam width," "beam angle," "antenna," "antenna element," "panel," etc. may be used interchangeably.

[0450] In this 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.

[0451] 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 divided 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 term "cell" or "sector" refers to a part or the entire coverage area of ​​a base station and / or base station subsystem that provides communication service within this coverage.

[0452] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0453] 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.

[0454] 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. At least one of the base station and the mobile station may be a device mounted on a mobile object, or the mobile object itself. 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). 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.

[0455] 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 uplink channel and downlink channel may be read as sidelink channel.

[0456] 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.

[0457] 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) and a Serving-Gateway (S-GW)), or a combination thereof.

[0458] 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 specific order presented.

[0459] Each aspect / embodiment described in the present disclosure may be related to 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) (xG (x is, for example, an integer or a decimal)), 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 The present invention may be applied to systems that use 802.20, Ultra-Wide Band (UWB), Bluetooth (registered trademark), or other appropriate wireless communication methods, or to next-generation systems that are based on and extend these systems. Furthermore, the present invention may be applied to a combination of multiple systems (for example, a combination of LTE or LTE-A and 5G).

[0460] 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."

[0461] 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.

[0462] 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.

[0463] 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.

[0464] Also, "decision" may be considered to be "deciding" resolving, selecting, choosing, establishing, comparing, etc. In other words, "decision" may be considered to be "deciding" on some action.

[0465] Furthermore, "judgment (decision)" may be interpreted as "assuming," "expecting," "considering," or the like.

[0466] 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.

[0467] 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."

[0468] 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.

[0469] 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."

[0470] When used in this disclosure, the terms "include," "including," and variations thereof are intended to be inclusive, similar to the term "comprising." Furthermore, when used in this disclosure, the term "or" is not intended to be an exclusive or.

[0471] 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.

[0472] 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 invention according to the present disclosure can be implemented in modified and altered forms without departing from the spirit and scope of the invention as defined by the description of the claims. Therefore, the description of the present disclosure is intended to be illustrative and does not impose any limiting meaning on the invention according to the present disclosure.

Claims

1. a receiver for receiving at least one synchronization signal block of the first number of first synchronization signal blocks and at least one synchronization signal block of the second number of second synchronization signal blocks; a control unit that controls reception assuming that the at least one synchronization signal block of the second number of second synchronization signal blocks is quasi-collocated (QCL) with the at least one synchronization signal block of the first number of first synchronization signal blocks, and controls initial access based on the at least one synchronization signal block of the first number of first synchronization signal blocks or the at least one synchronization signal block of the second number of second synchronization signal blocks; When a first demodulation reference signal of a downlink is QCL'd with the at least one synchronization signal block of a first number of the first synchronization signal blocks and a second demodulation reference signal of a downlink is QCL'd with the at least one synchronization signal block of the second number of the second synchronization signal blocks, the control unit controls reception of the terminal assuming that the second demodulation reference signal is QCL'd with the first demodulation reference signal.

2. The terminal according to claim 1, wherein the control unit performs initial access using the first synchronization signal block when the first synchronization signal block is received, and performs initial access using the second synchronization signal block when the first synchronization signal block is not received or when initial access using the first synchronization signal block fails.

3. The terminal according to claim 1 or 2, wherein the second number is greater than the first number.

4. 4. The terminal according to claim 1, wherein a transmission period of the second synchronization signal block is different from a transmission period of the first synchronization signal block.

5. The terminal according to claim 1 , wherein the second synchronization signal block is transmitted aperiodically.

6. receiving at least one synchronization signal block of a first number of first synchronization signal blocks and at least one synchronization signal block of a second number of second synchronization signal blocks; controlling reception assuming that the at least one synchronization signal block of the second number of second synchronization signal blocks is quasi-collocated (QCL) with the at least one synchronization signal block of the first number of first synchronization signal blocks; performing an initial access based on the at least one synchronization signal block of the first number of first synchronization signal blocks or the at least one synchronization signal block of the second number of second synchronization signal blocks; A wireless communication method for a terminal, wherein, when a first demodulation reference signal of a downlink is QCL'd with the at least one synchronization signal block of a first number of the first synchronization signal blocks and a second demodulation reference signal of a downlink is QCL'd with the at least one synchronization signal block of the second number of the second synchronization signal blocks, the control unit controls reception by assuming that the second demodulation reference signal is QCL'd with the first demodulation reference signal.

7. a transmitter that transmits a first number of first synchronization signal blocks and a second number of second synchronization signal blocks; a control unit that controls transmission assuming that at least one synchronization signal block of the second number of second synchronization signal blocks is quasi-collocated (QCL) with at least one synchronization signal block of the first number of first synchronization signal blocks, and controls initial access based on the at least one synchronization signal block of the first number of first synchronization signal blocks or the at least one synchronization signal block of the second number of second synchronization signal blocks; When a first demodulation reference signal of a downlink is QCL'd with the at least one synchronization signal block of a first number of the first synchronization signal blocks and a second demodulation reference signal of a downlink is QCL'd with the at least one synchronization signal block of the second number of the second synchronization signal blocks, the control unit controls transmission by assuming that the second demodulation reference signal is QCL'd with the first demodulation reference signal.

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