Apparatus and method for performing prach repetition transmission for CFRA in wireless communication system

Abstract

An operation method of a user equipment (UE) in a wireless communication system is provided, the method comprising the steps of: transmitting a preamble of a contention free random access (CFRA) procedure to a base station (BS); receiving a random-access response (RAR) of the CFRA procedure from the base station; transmitting a physical uplink shared channel (PUSCH) including message 3 (Msg3) of the CFRA procedure to the base station on the basis of a first beam indicated by the RAR; receiving, from the base station, downlink control information format 0_0 (DCI format 0_0) indicating retransmission of the PUSCH; and performing the retransmission of the PUSCH on the basis of a second beam indicated by the DCI format 0_0.

Description

Device and method for performing PRACH repetitive transmission for CFRA in a wireless communication system

[0001] The present disclosure relates to a wireless communication system. Specifically, the present disclosure relates to a device and method for performing PRACH (physical random access channel) repetitive transmission for CFRA (contention free random access) in a wireless communication system.

[0002]

[0003] NR supports multiple numerologies (or subcarrier spacings (SCS)) to support various 5G services. For example, an SCS of 15 kHz supports a wide area in traditional cellular bands, an SCS of 30 kHz / 60 kHz supports dense urban areas, lower latency, and wider carrier bandwidth, and an SCS of 60 kHz or higher supports a bandwidth greater than 24.25 GHz to overcome phase noise.

[0004] In 3GPP Release-18 (Rel-18) coverage enhancement, a random access channel occasion group (RACH occasion group, RO group) was introduced for PRACH repetition (physical random access channel repetition, PRACH repetition), and an RO group was defined to be formed using only ROs located at the same frequency.

[0005] Meanwhile, since PRACH repetition is primarily defined to target contention-based random access (CBRA), additional terminal / base station operations may be required when contention-free random access (CFRA) is introduced. Therefore, this specification proposes the necessary terminal / base station operations when CFRA is defined in a situation where PRACH preamble repetition operation is used.

[0006] The operations of the terminal / base station related to CFRA considered in this specification are as follows. That is, when the terminal performs CFRA, the base station receives the PRACH preamble (i.e., message A preamble) that the terminal repeatedly transmits through ROs promised or instructed between the base station and the terminal, and if the PRACH preamble of a specific terminal is detected in at least one RO among the received PRACH preambles, the base station transmits a RAR message (random access response message) to the terminal that transmitted the PRACH preamble. The terminal monitors whether the RAR message provided by the base station has been transmitted in the RAR window promised in advance, and if detected, receives the RAR message.

[0007]

[0008] To solve the above-described problem, the present disclosure provides a device and method for performing PRACH (physical random access channel) repetitive transmission for CFRA (contention free random access) in a wireless communication system.

[0009] The technical problems to be achieved in the present disclosure are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present disclosure belongs from the description below.

[0010]

[0011] According to various embodiments of the present disclosure, a method of operating a user equipment (UE) in a wireless communication system is provided, the method comprising: transmitting a preamble of a contention free random access (CFRA) procedure to a base station (BS); receiving a random access response (RAR) of the CFRA procedure from the base station; transmitting a physical uplink shared channel (PUSCH) including message 3 (Msg3) of the CFRA procedure to the base station based on a first beam indicated by the RAR; receiving a downlink control information format 0_0 (DCI format 0_0) indicating retransmission of the PUSCH from the base station; and performing the retransmission of the PUSCH based on a second beam indicated by the DCI format 0_0.

[0012] According to various embodiments of the present disclosure, a method of operating a base station (BS) in a wireless communication system is provided, the method comprising: receiving a preamble of a contention free random access (CFRA) procedure from a user equipment (UE); transmitting a random access response (RAR) of the CFRA procedure to the UE; receiving a physical uplink shared channel (PUSCH) including a message 3 (Msg3) of the CFRA procedure from the UE based on a first beam indicated by the RAR; transmitting a downlink control information format 0_0 (DCI format 0_0) indicating a retransmission of the PUSCH to the UE; and receiving the retransmission of the PUSCH based on a second beam indicated by the DCI format 0_0.

[0013] According to various embodiments of the present disclosure, in a wireless communication system, a terminal is provided, comprising: a transceiver; at least one processor; and at least one memory operably connectable to the at least one processor and storing instructions that, when executed by the at least one processor, perform operations, wherein the operations include all steps of a method of operating the terminal according to various embodiments of the present disclosure.

[0014] According to various embodiments of the present disclosure, in a wireless communication system, a base station is provided, comprising: a transceiver, at least one processor, and at least one memory operably connectable to the at least one processor and storing instructions that, when executed by the at least one processor, perform operations, wherein the operations include all steps of a method of operating the base station according to various embodiments of the present disclosure.

[0015] According to various embodiments of the present disclosure, a control device for controlling a terminal in a wireless communication system is provided, the control device including at least one processor and at least one memory operably connected to the at least one processor, wherein the at least one memory stores instructions for performing operations based on being executed by the at least one processor, the operations including all steps of an operating method of the terminal according to various embodiments of the present disclosure.

[0016] According to various embodiments of the present disclosure, a control device for controlling a base station in a wireless communication system is provided, comprising at least one processor and at least one memory operably connected to the at least one processor, wherein the at least one memory stores instructions for performing operations based on being executed by the at least one processor, wherein the operations include all steps of a method of operating a base station according to various embodiments of the present disclosure.

[0017] According to various embodiments of the present disclosure, there is provided one or more non-transitory computer-readable media storing one or more commands, wherein the one or more commands perform operations based on being executed by one or more processors, the operations including all steps of a method of operating a terminal according to various embodiments of the present disclosure.

[0018] According to various embodiments of the present disclosure, there is provided one or more non-transitory computer-readable media storing one or more commands, wherein the one or more commands, when executed by one or more processors, perform operations, the operations including all steps of a method of operating a base station according to various embodiments of the present disclosure.

[0019]

[0020] In order to solve the above-described problem, the present disclosure can provide a device and method for performing PRACH (physical random access channel) repeated transmission for CFRA (contention free random access) in a wireless communication system.

[0021]

[0022] The accompanying drawings are intended to aid in understanding the present disclosure and, together with detailed descriptions, may provide embodiments of the present disclosure. However, the technical features of the present disclosure are not limited to specific drawings, and the features disclosed in each drawing may be combined with each other to form new embodiments. Reference numerals in each drawing may indicate structural elements.

[0023] FIG. 1 is a diagram illustrating an example of physical channels used in a system applicable to the present disclosure and a general signal transmission method using the same.

[0024] FIG. 2 is a diagram illustrating an example of a wireless frame structure used in a system applicable to the present disclosure.

[0025] FIG. 3 is a drawing illustrating an example of a slot structure used in a system applicable to the present disclosure.

[0026] FIG. 4 is a diagram illustrating an example of a slot structure of a wireless frame used in a system applicable to the present disclosure.

[0027] FIG. 5 is a diagram illustrating an example of the operation process of a terminal in a system applicable to the present disclosure.

[0028] FIG. 6 is a diagram illustrating an example of an operation process of a base station in a system applicable to the present disclosure.

[0029] FIG. 7 is a drawing showing an example of the structure of a first device and a second device in a system applicable to the present disclosure.

[0030]

[0031] In various embodiments of the present disclosure, “A or B” may mean “only A,” “only B,” or “both A and B.” In other words, in various embodiments of the present disclosure, “A or B” may be interpreted as “A and / or B.” For example, in various embodiments of the present disclosure, “A, B or C” may mean “only A,” “only B,” “only C,” or “any combination of A, B and C.”

[0032] In various embodiments of the present disclosure, a slash ( / ) or a comma may mean "and / or." For example, "A / B" may mean "A and / or B." Accordingly, "A / B" may mean "only A," "only B," or "both A and B." For example, "A, B, C" may mean "A, B, or C."

[0033] In various embodiments of the present disclosure, “at least one of A and B” may mean “only A,” “only B,” or “both A and B.” Furthermore, in various embodiments of the present disclosure, the expressions “at least one of A or B” or “at least one of A and / or B” may be interpreted as equivalent to “at least one of A and B.”

[0034] Additionally, in various embodiments of the present disclosure, “at least one of A, B and C” can mean “only A,” “only B,” “only C,” or “any combination of A, B and C.” Additionally, “at least one of A, B or C” or “at least one of A, B and / or C” can mean “at least one of A, B and C.”

[0035] Additionally, parentheses used in various embodiments of the present disclosure may mean "for example." Specifically, when indicated as "control information (PDCCH)", "PDCCH" may be proposed as an example of "control information." In other words, "control information" in various embodiments of the present disclosure is not limited to "PDCCH", and "PDDCH" may be proposed as an example of "control information." Furthermore, even when indicated as "control information (i.e., PDCCH)", "PDCCH" may be proposed as an example of "control information."

[0036] Technical features individually described in a single drawing in various embodiments of the present disclosure may be implemented individually or simultaneously.

[0037]

[0038] Common signal transmission methods in 3GPP

[0039] Physical channels and general signal transmission

[0040] FIG. 1 is a diagram illustrating an example of physical channels used in a system applicable to the present disclosure and a general signal transmission method using these channels. Specifically, FIG. 1 illustrates physical channels used in a 3GPP system and general signal transmission.

[0041] Figure 1 illustrates the physical channels and typical signal transmission used in the 3GPP system. In a wireless communication system, a terminal receives information from a base station via the downlink (DL), and the terminal transmits information to the base station via the uplink (UL). The information transmitted and received between the base station and the terminal includes data and various control information, and various physical channels exist depending on the type and purpose of the information they transmit and receive.

[0042] When a terminal is powered on again from a powered-off state or newly enters a cell, it performs an initial cell search operation, such as synchronizing with the base station (S11). To this end, the terminal receives the PSCH (Primary Synchronization Channel) and SSCH (Secondary Synchronization Channel) from the base station to synchronize with the base station and obtain information such as the cell ID (cell identity). In addition, the terminal can obtain broadcast information within the cell by receiving the PBCH (Physical Broadcast Channel) from the base station. In addition, the terminal can receive the DL RS (Downlink Reference Signal) during the initial cell search phase to check the downlink channel status.

[0043] A terminal that has completed initial cell search can obtain more specific system information by receiving a PDCCH (Physical Downlink Control Channel) and a corresponding PDSCH (Physical Downlink Control Channel) (S12).

[0044] Thereafter, the terminal may perform a random access procedure to complete connection to the base station (S13-S16). Specifically, the terminal may transmit a preamble via a physical random access channel (PRACH) (S13) and receive a random access response (RAR) for the preamble via a physical downlink control channel (PDCCH) and a corresponding PDSCH (S14). Thereafter, the terminal may transmit a physical uplink shared channel (PUSCH) using scheduling information in the RAR (S15) and perform a contention resolution procedure such as a PDCCH and a corresponding PDSCH (S16).

[0045] A terminal that has performed the above-described procedure can then perform PDCCH / PDSCH reception (S17) and PUSCH / PUCCH (Physical Uplink Control Channel) transmission (S18) as general uplink / downlink signal transmission procedures. Control information that the terminal transmits to the base station is referred to as UCI (Uplink Control Information). UCI includes HARQ ACK / NACK (Hybrid Automatic Repeat and reQuest Acknowledgement / Negative-ACK), SR (Scheduling Request), CSI (Channel State Information), etc. CSI includes CQI (Channel Quality Indicator), PMI (Precoding Matrix Indicator), RI (Rank Indication), etc. UCI is generally transmitted through PUCCH, but can be transmitted through PUSCH when control information and data must be transmitted simultaneously. In addition, the terminal can aperiodically transmit UCI through PUSCH according to a request / instruction of the network.

[0046]

[0047] OFDM (Orthogonal Frequency Division Multiplexing) Numerology

[0048] The new RAT system uses OFDM transmission scheme or a similar transmission scheme. The new RAT system may follow OFDM parameters different from those of LTE. Alternatively, the new RAT system may follow the existing LTE / LTE-A numerology but have a larger system bandwidth (e.g., 100 MHz). Alternatively, a single cell may support multiple numerologies. That is, UEs operating under different numerologies can coexist within a single cell.

[0049]

[0050] Radio frame structure

[0051] FIG. 2 is a diagram illustrating an example of the structure of a wireless frame used in a system applicable to the present disclosure.

[0052] In NR, uplink and downlink transmissions are organized into frames. A radio frame is 10 ms long and is defined by two 5 ms half-frames (HF). Each half-frame is defined by five 1 ms subframes (SF). A subframe is divided into one or more slots, and the number of slots in a subframe depends on the subcarrier spacing (SCS). Each slot contains 12 or 14 OFDM(A) symbols, depending on the cyclic prefix (CP). When a regular CP is used, each slot contains 14 symbols. When an extended CP is used, each slot contains 12 symbols. Here, the symbols can include OFDM symbols (or CP-OFDM symbols), SC-FDMA symbols (or DFT-s-OFDM symbols).

[0053] Table 1 illustrates that when CP is normally used, the number of symbols per slot, the number of slots per frame, and the number of slots per subframe vary depending on the SCS.

[0054] SCS (15*2^u)N slot symb N frame,u slot N subframe,u slot 15KHz (u=0)1410130KHz (u=1)1420260KHz (u=2)14404120KHz (u=3)14808240KHz (u=4)1416016

[0055] N slot symb is the number of symbols in the slot. N frame,uslot is the number of slots in the frame. N subframe,u slot is the number of slots within a subframe.

[0056]

[0057] Table 2 illustrates that when extended CP is used, the number of symbols per slot, the number of slots per frame, and the number of slots per subframe vary depending on the SCS.

[0058] SCS (15*2^u)N slot symb N frame,u slot N subframe,u slot 60KHz (u=2)12404

[0059] NR supports multiple numerologies (or subcarrier spacings (SCS)) to support various 5G services. For example, an SCS of 15 kHz supports wide areas in traditional cellular bands; an SCS of 30 kHz / 60 kHz supports dense urban areas, lower latency, and wider carrier bandwidth; and an SCS of 60 kHz or higher supports bandwidths greater than 24.25 GHz to overcome phase noise.

[0060] The NR frequency band can be defined by two types of frequency ranges (FR1, FR2). The numerical values ​​of the frequency ranges can be changed, and for example, the two types of frequency ranges (FR1, FR2) can be as shown in Table 3 below. For convenience of explanation, among the frequency ranges used in the NR system, FR1 can mean the "sub 6 GHz range", and FR2 can mean the "above 6 GHz range" and can be called millimeter wave (mmW).

[0061] Frequency Range designationCorresponding frequency rangeSubcarrier SpacingFR1450MHz - 6000MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0062] As described above, the numerical value of the frequency range of the NR system can be changed. For example, FR1 may include a band from 410 MHz to 7125 MHz, as shown in Table 4 below. That is, FR1 may include a frequency band above 6 GHz (or 5850, 5900, 5925 MHz, etc.). For example, the frequency band above 6 GHz (or 5850, 5900, 5925 MHz, etc.) included within FR1 may include an unlicensed band. The unlicensed band may be used for various purposes, such as for vehicular communications (e.g., autonomous driving).

[0063] Frequency Range designationCorresponding frequency rangeSubcarrier SpacingFR1410MHz - 7125MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0064] In an NR system, OFDM(A) numerologies (e.g., SCS, CP length, etc.) may be set differently between multiple cells that are merged into a single terminal. Accordingly, the (absolute time) interval of a time resource (e.g., SF, slot, or TTI) (conveniently referred to as TU (Time Unit)) consisting of the same number of symbols may be set differently between the merged cells.

[0065] FIG. 3 is a drawing illustrating an example of a slot structure used in a system applicable to the present disclosure.

[0066] A slot contains multiple symbols in the time domain. For example, a slot contains 7 symbols for a regular CP, but 6 symbols for an extended CP. A carrier contains multiple subcarriers in the frequency domain. A Resource Block (RB) is defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. A Bandwidth Part (BWP) is defined as multiple consecutive (P)RBs in the frequency domain, and can correspond to a single numerology (e.g., SCS, CP length, etc.). A carrier can contain up to N (e.g., 5) BWPs. Data communication is performed through activated BWPs, and only one BWP can be activated for a single terminal. Each element in the resource grid is referred to as a Resource Element (RE), to which one complex symbol can be mapped.

[0067]

[0068] FIG. 4 is a diagram illustrating an example of a slot structure of a wireless frame used in a system applicable to the present disclosure.

[0069] Fig. 4 is an exemplary system, illustrating the slot structure of a frame of an NR system.

[0070] The frame structure of NR is characterized by a self-contained structure in which a DL control channel, DL or UL data, and UL control channel can all be included in a single slot unit, as shown in the example of FIG. 4. At this time, DL data scheduling information, UL data scheduling information, etc. can be transmitted in the DL control channel, and ACK / NACK information for DL ​​data, CSI information (modulation and coding scheme information, MIMO transmission-related information, etc.), scheduling requests, etc. can be transmitted in the UL control channel. In FIG. 4, a time gap for DL-to-UL or UL-to-DL switching may exist between the control region and the data region. In addition, some of DL control / DL data / UL data / UL control may not be configured within a single slot. Or, the order of each channel configuring a single slot may be different. (For example, DL control / DL data / UL control / UL data or UL control / UL data / DL control / DL data, etc.)

[0071]

[0072] Composition and Method of the Invention

[0073] The contents examined above (NR frame structure, RACH, U-Band system, etc.) can be applied in combination with the methods proposed in this specification, which will be described later, or can be supplemented to clarify the technical characteristics of the methods proposed in this specification.

[0074] In addition, the methods related to the PRACH transmission occasion configuration described later are related to uplink transmission and can be equally applied to the uplink signal transmission method in the NR system (licensed band) or U-Band system (unlicensed band) described above, and of course, the technical idea proposed in this specification can be modified or replaced to fit the terms, expressions, structures, etc. defined in each system so that it can be implemented in the relevant system as well.

[0075] For example, uplink transmission through methods related to the PRACH transmission occasion configuration described below can be performed in an L-cell and / or U-cell defined in an NR system or a U-Band system.

[0076] NR supports multiple numerologies (or subcarrier spacings (SCS)) to support various 5G services. For example, an SCS of 15 kHz supports wide areas in traditional cellular bands; an SCS of 30 kHz / 60 kHz supports dense urban areas, lower latency, and wider carrier bandwidth; and an SCS of 60 kHz or higher supports bandwidths greater than 24.25 GHz to overcome phase noise.

[0077] In 3GPP Release-18 (Rel-18) coverage enhancement, RO group (random access channel occasion group, RACH occasion group) was introduced for PRACH repetition (physical random access channel repetition), and it was defined that an RO group is formed using only ROs located at the same frequency.

[0078] Meanwhile, since PRACH repetition is primarily defined to target CBRA (contention-based random access), additional terminal / base station operations may be required when CFRA (contention-free random access) is introduced. Therefore, this specification proposes the necessary terminal / base station operations when CFRA is defined in a situation where PRACH (Msg. A) preamble repetition operation is used.

[0079] The operations of the terminal / base station related to CFRA considered in this specification are as follows. That is, when the terminal performs CFRA, the base station receives the PRACH preamble that the terminal repeatedly transmits through ROs promised or instructed between the base station and the terminal, and if the PRACH preamble of a specific terminal is detected in at least one RO among the received PRACH preambles, the base station transmits a RAR message (random access response message) to the terminal that transmitted the PRACH preamble. The terminal monitors whether the RAR message provided by the base station has been transmitted within the RAR window promised in advance, and if detected, receives the RAR message.

[0080]

[0081] 1. How to indicate starting RO through PRACH Mask index

[0082] According to 3GPP TS (technical specification) 38.212, if the CRC of DCI format 1_0 is scrambled with C-RNTI and the FDRA (frequency domain resource allocation) field value is set to all 1, the DCI format 1_0 is defined to indicate a RACH procedure initiated in PDCCH order. At this time, the PRACH Mask index field of the DCI format 1_0 is defined to indicate the time domain index of the RO (RACH occasion) corresponding to the SSB index (synchronization signal block index) indicated by the SS / PBCH index field of the same DCI.

[0083] However, in a situation where PRACH repeated transmission is considered, it is important for the terminal to know the location of the starting RO among multiple ROs (i.e., RO group) to be used for a specific PRACH repeated transmission. Therefore, the base station can be defined to inform the terminal of the time domain index of the starting RO of the RO group associated with the SSB index indicated by the SS / PBCH index field using the corresponding PRACH Mask index. The terminal can be configured to receive the information and perform CFRA by selecting one or more of the indicated starting ROs.

[0084] First, we propose a method to modify section 7.3.1.2.1 of 3GPP TS 38.212. For example, in the sentence that previously only mentioned single PRACH transmission, a definition could be added that for multiple PRACH transmission, the PRACH Mask index value indicates the first RO associated with the SSB index.

[0085] [Chapter 7.3.1.2.1 in 3GPP TS 38.212: Underlined portions are those proposed in this disclosure]

[0086] The following information is transmitted by means of the DCI format 1_0 with CRC scrambled by C-RNTI, CS-RNTI, or MCS-C-RNTI:

[0087] - Identifier for DCI formats - 1 bit

[0088] - The value of this bit field is always set to 1, indicating a DL DCI format.

[0089] - Frequency domain resource assignment - Beat, here, is given by Section 7.3.1.0 ( bits where is given by clause 7.3.1.0)

[0090] If the CRC of the DCI format 1_0 is scrambled by C-RNTI and the "Frequency domain resource assignment" field are of all ones, the DCI format 1_0 is for a random access procedure initiated by a PDCCH order, with all remaining fields set as follows:

[0091] - Random Access Preamble Index - 6 bits according to ra-PreambleIndex in Clause 5.1.2 of [8, TS38.321]

[0092] - UL / SUL indicator - 1 bit. If the value of the "Random Access Preamble index" is not all zeros and the UE is configured with supplementaryUplink in ServingCellConfig in the cell, this field indicates which UL carrier in the cell to transmit the PRACH according to Table 7.3.1.1.1-1; otherwise, this field is reserved.

[0093] - SS / PBCH index (SS / PBCH index) - 6 bits. If the value of the "Random Access Preamble index" is not all zeros, this field indicates the SS / PBCH that shall be used to determine the RACH occasion for the PRACH transmission. Otherwise, this field is reserved.

[0094] - PRACH Mask Index - 4 bits. If the value of the "Random Access Preamble index" is not all zeros, this field indicates the RACH occasion associated with the SS / PBCH indicated by the "SS / PBCH index" for the PRACH transmission, or indicates the first RACH occasion associated with the SS / PBCH indicated by the "SS / PBCH index" for the multiple PRACH transmissions, according to Clause 5.1.1 of [8, TS38.321]; Otherwise, this field is reserved.

[0095] - Reserved bits - 12 bits for operation in a cell with shared spectrum channel access in frequency range 1 or when the DCI format is monitored in common search space for operation in a cell in frequency range 2-2; otherwise 10 bits

[0096]

[0097] As another example, you might consider revising it as follows to avoid unnecessary repetition of sentences:

[0098] [Chapter 7.3.1.2.1 in 3GPP TS 38.212: Underlined portions are those proposed in this disclosure]

[0099] The following information is transmitted by means of the DCI format 1_0 with CRC scrambled by C-RNTI, CS-RNTI, or MCS-C-RNTI:

[0100] - Identifier for DCI formats - 1 bit

[0101] - The value of this bit field is always set to 1, indicating a DL DCI format.

[0102] - Frequency domain resource assignment - Beat, here, is given by Section 7.3.1.0 ( bits where is given by clause 7.3.1.0)

[0103] If the CRC of the DCI format 1_0 is scrambled by C-RNTI and the "Frequency domain resource assignment" field are of all ones, the DCI format 1_0 is for a random access procedure initiated by a PDCCH order, with all remaining fields set as follows:

[0104] - Random Access Preamble Index - 6 bits according to ra-PreambleIndex in Clause 5.1.2 of [8, TS38.321]

[0105] - UL / SUL indicator - 1 bit. If the value of the "Random Access Preamble index" is not all zeros and the UE is configured with supplementaryUplink in ServingCellConfig in the cell, this field indicates which UL carrier in the cell to transmit the PRACH according to Table 7.3.1.1.1-1; otherwise, this field is reserved.

[0106] - SS / PBCH index (SS / PBCH index) - 6 bits. If the value of the "Random Access Preamble index" is not all zeros, this field indicates the SS / PBCH that shall be used to determine the RACH occasion for the PRACH transmission. Otherwise, this field is reserved.

[0107] - PRACH Mask Index - 4 bits. If the value of the "Random Access Preamble index" is not all zeros, this field indicates the RACH occasion associated with the SS / PBCH indicated by the "SS / PBCH index" for the first PRACH transmission, according to Clause 5.1.1 of [8, TS38.321]; otherwise, this field is reserved.

[0108] - Reserved bits - 12 bits for operation in a cell with shared spectrum channel access in frequency range 1 or when the DCI format is monitored in common search space for operation in a cell in frequency range 2-2; otherwise 10 bits

[0109]

[0110] Next, we propose a method to modify section 8.1 of 3GPP TS 38.213. For example, for the existing sentence that only mentions a single PRACH transmission, we can add a definition that for multiple PRACH transmissions, the PRACH Mask index value indicates the first RO (first RACH occasion, first RO) associated with the SSB index.

[0111] [Chapter 8.1 in 3GPP TS 38.213: Underlined portions are those proposed in this disclosure]

[0112] For a PRACH transmission of a UE triggered by a PDCCH command, if the value of the Random Access Preamble Index field is not 0, the PRACH Mask Index field [5, TS 38.212] indicates a PRACH opportunity for a PRACH transmission, or Indicates the first PRACH opportunity for PRACH transmission with preamble repetition. Here, the PRACH opportunity is associated with the SS / PBCH block index indicated by the SS / PBCH block index field of the PDCCH command. If the UE is assigned K by cellSpecificKoffset, cell,offset If offered, PRACH opportunity is slot After, where n is T TA= 0, is the slot of the UL BWP for PRACH transmission overlapping the end of the PDCCH command reception, and μ is the SCS configuration for the PRACH transmission. If the PDCCH reception for the PDCCH command includes two PDCCH candidates among two linked search space sets based on searchSpaceLinkingId as described in Section 10.1, the last symbol of the PDCCH reception is the last symbol of the PDCCH candidate that ends later. Even if the UE does not need to monitor one of the two PDCCH candidates as described in Sections 10 (except Section 10.4), 11.1, 11.1.1, and 17.2, the PDCCH reception includes two PDCCH candidates. (For a PRACH transmission by a UE triggered by a PDCCH order, the PRACH mask index field [5, TS 38.212], if the value of the random access preamble index field is not zero, indicates the PRACH occasion for the PRACH transmission, or indicates the first PRACH occasion for the PRACH transmission with preamble repetitionswhere the PRACH occasions are associated with the SS / PBCH block index indicated by the SS / PBCH block index field of the PDCCH order. If the UE is provided K cell,offset bycellSpecificKoffset, the PRACH occasion is after slot where n is the slot of the UL BWP for the PRACH transmission that overlaps with the end of the PDCCH order reception assuming T TA =0, and μ is the SCS configuration for the PRACH transmission. If the PDCCH reception for the PDCCH order includes two PDCCH candidates from two linked search space sets based onsearchSpaceLinkingId, as described in clause 10.1, the last symbol of the PDCCH reception is the last symbol of the PDCCH candidate that ends later. The PDCCH reception includes the two PDCCH candidates also when the UE is not required to monitor one of the two PDCCH candidates as described in clauses 10 (except clause 10.4), 11.1, 11.1.1 and 17.2.)

[0113]

[0114] As another example, you might consider revising it as follows to avoid unnecessary repetition of sentences:

[0115] [Chapter 8.1 in 3GPP TS 38.213: Underlined portions are those proposed in this disclosure]

[0116] For a PRACH transmission of a UE triggered by a PDCCH command, if the value of the Random Access Preamble Index field is not 0, the PRACH Mask Index field [5, TS 38.212] indicates the first PRACH opportunity for a PRACH transmission. Here, the PRACH opportunity is associated with the SS / PBCH block index indicated by the SS / PBCH block index field of the PDCCH command. If the UE has K by cellSpecificKoffset, cell,offset If offered, PRACH opportunity is slot After, where n is T TA= 0, is the slot of the UL BWP for PRACH transmission overlapping the end of the PDCCH command reception, and μ is the SCS configuration for the PRACH transmission. If the PDCCH reception for the PDCCH command includes two PDCCH candidates among two linked search space sets based on searchSpaceLinkingId as described in Section 10.1, the last symbol of the PDCCH reception is the last symbol of the PDCCH candidate that ends later. Even if the UE does not need to monitor one of the two PDCCH candidates as described in Sections 10 (except Section 10.4), 11.1, 11.1.1, and 17.2, the PDCCH reception includes two PDCCH candidates. (For a PRACH transmission by a UE triggered by a PDCCH order, the PRACH mask index field [5, TS 38.212], if the value of the random access preamble index field is not zero, indicates thefirstPRACH occasion for the PRACH transmission where the PRACH occasions are associated with the SS / PBCH block index indicated by the SS / PBCH block index field of the PDCCH order. If the UE is provided K cell,offset bycellSpecificKoffset, the PRACH occasion is after slot where n is the slot of the UL BWP for the PRACH transmission that overlaps with the end of the PDCCH order reception assuming T TA=0, and μ is the SCS configuration for the PRACH transmission. If the PDCCH reception for the PDCCH order includes two PDCCH candidates from two linked search space sets based onsearchSpaceLinkingId, as described in clause 10.1, the last symbol of the PDCCH reception is the last symbol of the PDCCH candidate that ends later. The PDCCH reception includes the two PDCCH candidates also when the UE is not required to monitor one of the two PDCCH candidates as described in clauses 10 (except clause 10.4), 11.1, 11.1.1 and 17.2.)

[0117]

[0118] Meanwhile, for example, for ReconfigurationWithSync or BFR, the PRACH mask index is also indicated when CFRA is indicated by an RRC signaling rather than a PDCCH order. Specifically, in section 6.3.2 of 3GPP TS 38.331, ra-ssb-OccasionMaskIndex in RACH-ConfigDedicated indicates the PRACH mask index.

[0119] [RACH-ConfigDedicated in Chapter 6.3.2 of 3GPP TS 38.331]

[0120] - RACH-ConfigDedicated

[0121] IERACH-ConfigDedicated is used to specify dedicated random access parameters.

[0122] [RACH-ConfigDedicated information element]

[0123] CFRA ::= SEQUENCE { (CFRA ::= SEQUENCE {)

[0124] Opportunities SEQUENCE { (occasions SEQUENCE {)

[0125] rach-ConfigGeneric RACH-ConfigGeneric,

[0126] ssb-perRACH-Occasion ENUMERATED {oneEighth, oneFourth, oneHalf, one, two, four,ight, sixteen} OPTIONAL -- Cond Mandatory

[0127] } OPTIONAL, -- Need S

[0128] Resources CHOICE {

[0129] ssb sequence { (ssb SEQUENCE {)

[0130] CFRA-SSB-리소스 ssb-ResourceList 시군스(SIZE(1..maxRA-SSB-리소스)), (ssb-ResourceList SEQUENCE (SIZE(1..maxRA-SSB-Resources)) OF CFRA-SSB-Resource,)

[0131] ra-ssb-OccasionMaskIndex INTEGER (0..15)

[0132] },

[0133] csirs 시연스 { (csirs SEQUENCE {)

[0134] CFRA-CSIRS-자원 csirs-ResourceList SEQUENCE (SIZE(1..maxRA-CSIRS-Resources)), (csirs-ResourceList SEQUENCE (SIZE(1..maxRA-CSIRS-Resources)) OF CFRA-CSIRS-Resource,)

[0135] rsrp-ThresholdCSI-RS RSRP-Range

[0136] }

[0137] },

[0138] ...,

[0139] [[

[0140] totalNumberOfRA-Preambles INTEGER (1..63) OPTIONAL -- Cond Occasions

[0141] ]]

[0142] }

[0143]

[0144] [RACH-ConfigDedicated field descriptions]

[0145] ra-ssb-OccasionMaskIndex: Explicitly signaled PRACH mask index for RA resource selection in TS 38.321 [3]. The mask is valid for all SSB resources signaled in ssb-ResourceList.

[0146]

[0147] At this time, the method proposed for the above PRACH mask index can be extended and applied to ra-ssb-OccasionMaskIndex. That is, the base station can be defined to use the ra-ssb-OccasionMaskIndex to inform the terminal of the time domain index of the starting RO of the RO group associated with the SSB index indicated by ssb-ResourceList. The terminal can be configured to receive the information and perform CFRA by selecting one or more of the indicated starting ROs.

[0148] First, we propose a method to modify section 6.3.2 of 3GPP TS 38.331. For example, we can leave the existing sentence as is and add a definition that, for multiple PRACH transmission, the ra-ssb-OccasionMaskIndex value indicates the first RO associated with the SSB index.

[0149]

[0150] [RACH-ConfigDedicated field descriptions: The underlined part is the part proposed in this disclosure]

[0151] ra-ssb-OccasionMaskIndex: Explicitly signaled PRACH Mask Index for RA Resource selection in TS 38.321 [3]. The mask is valid for all SSB resources signaled in ssb-ResourceList. If msg1 repetition is enabled, the PRACH Mask Index indicates the first RACH occasion associated with the SS / PBCH indicated by " ssb-ResourceList " for the multiple PRACH transmissions.

[0152]

[0153] Meanwhile, a method of indicating an RO set index (i.e., an RO group index) rather than an RO index through the PRACH MASK index may be considered. In this case, a method for determining indexing for multiple RO sets associated with a specific SSB index needs to be introduced. For reference, the existing specification of 3GPP TS 38.213 defines the method for determining indexing for ROs associated with a specific SSB index as follows.

[0154]

[0155] PRACH occasions are consecutively mapped for each SS / PBCH block index. The indexing of the PRACH occasion indicated by the mask index value is reset per mapping cycle of consecutive PRACH occasions per SS / PBCH block index. The UE selects the PRACH occasion indicated by the PRACH mask index value for the indicated SS / PBCH block index in the first available mapping cycle for a PRACH transmission. (The PRACH occasions are consecutively mapped for each corresponding SS / PBCH block index. The indexing of the PRACH occasion indicated by the mask index value is reset per mapping cycle of consecutive PRACH occasions per SS / PBCH block index. The UE selects the PRACH occasion indicated by the PRACH mask index value for the indicated SS / PBCH block index in the first available mapping cycle.)

[0156] For the indicated preamble index, the order of PRACH cases is as follows.

[0157] For the indicated preamble index, the ordering of the PRACH occasions is

[0158] - First, in increasing order of frequency resource indexes for frequency multiplexed PRACH occasions

[0159] - Second, in increasing order of time resource indexes for time multiplexed PRACH occasions within a PRACH slot

[0160] - Third, in increasing order of indexes for PRACH slots

[0161]

[0162] A similar, but slightly different, approach could be introduced to determine the indexing for multiple RO sets associated with a specific SSB index. Specifically, the following operations could be considered:

[0163]

[0164] - When determining the order of multiple RO sets associated with a specific SSB index, the order can be determined based on the time / frequency position of a specific RO in each RO set. For example, the order can be determined based on the time / frequency position of the first RO in each RO set, or the time / frequency position of the last RO in each RO set. Alternatively, the base station can configure / indicate a specific RO in an RO set, or it can be predefined in the specification.

[0165] - Additionally, the ordering is done as frequency first / time second / PRACH slot third based on the time / frequency position of a specific RO included in each RO set, but additionally, the system frame number (i.e., SFN) can be considered fourth, and additionally, the hyper frame number (i.e., HFN) can also be considered.

[0166] - Meanwhile, the RO set index can be configured to be initialized every "time period" consisting of multiple association pattern periods defined for RO set determination. Additionally, the terminal can be configured to select the RO set index from the first available time period.

[0167]

[0168] Considering the above methods, for example, the RO set index ordering related operation can be defined as follows in 38.213. At this time, the ordering method based on the first RO included in the RO set was considered, and the frequency resource index was set to be the first, the time resource index the second, the PRACH slot index the third, and the SFN index the fourth for the index of the first RO.

[0169]

[0170] Indicated by the mask index value for PRACH repetition. For PRACH transmission with preamble repetition The indexing of the valid PRACH opportunity set is reset per SS / PBCH block index period. The UE uses the PRACH mask index value for PRACH repetition for the indicated SS / PBCH block index in the first available time period for multiple PRACH transmissions. Select a valid PRACH opportunity set. (The indexing of the set of valid PRACH occasions for a PRACH transmission with preamble repetitions indicated by the mask index value for PRACH repetition is reset per time period per SS / PBCH block index. The UE selects for multiple PRACH transmissions the set of valid PRACH occasions indicated by PRACH mask index value for PRACH repetition for the indicated SS / PBCH block index in the first available time period.)

[0171] For the indicated preamble index The ordering of the set of valid PRACH opportunities is as follows: (For the indicated preamble index, the ordering of the set of valid PRACH occasions is)

[0172] - First, about frequency multiplexed PRACH opportunities First, in increasing order of frequency resource indexes of the first PRACH occasion of the set of valid PRACH opportunities valid PRACH occasions for frequency multiplexed PRACH occasions)

[0173] - Second, for the case of time-multiplexed PRACH within the PRACH slot Second, in increasing order of time resource indexes of the first PRACH occasion of the set of valid PRACH opportunities valid PRACH occasions for time multiplexed PRACH occasions within a PRACH slot)

[0174] - Third, in increasing order of indexes for PRACH slots

[0175] - Fourth, in increasing order of indexes for SFN

[0176]

[0177] To use the above method, a new table including the RO set index as shown in Table 5 below can be added. Table 5 below shows the PRACH Mask Index values.

[0178]

[0179] PRACH Mask Index / msgA-SSB-SharedRO-MaskIndex / ssb-SharedRO-MaskIndex Allowed PRACH occasion(s) / set of PRACH occasions of SSB 0 All 1 PRACH opportunity index 1 or PRACH opportunity set index 1 2 PRACH opportunity index 2 or PRACH opportunity set index 2 3 PRACH opportunity index 3 or PRACH opportunity set index 3 4 PRACH opportunity index 4 or PRACH opportunity set index 4 5 PRACH opportunity index 5 or PRACH opportunity set index 5 (PRACH occasion index 5 or PRACH occasion set index 5)6PRACH opportunity index 6 or PRACH opportunity set index 6 (PRACH occasion index 6 or PRACH occasion set index 6)7PRACH opportunity index 7 or PRACH opportunity set index 7 (PRACH occasion index 7 or PRACH occasion set index 7)8PRACH opportunity index 8 or PRACH opportunity set index 8 (PRACH occasion index 8 or PRACH occasion set index 8)9Every even PRACH occasion or Every even PRACH occasionset)10Every odd PRACH occasion or Every odd PRACH occasion set11Reserved12Reserved13Reserved14Reserved15Reserved

[0180]

[0181] Meanwhile, depending on the msg1 repetition-related configurations, the number of RO set indices that can exist within a “time period” consisting of multiple association pattern periods may exceed 8 for each SSB beam index. In this case, the RO set indices can be defined to start from 1. This leads to the problem that RO set indices greater than 9 cannot be separately indicated using Table 5 above.

[0182] Therefore, to solve this problem, the cycle for initializing the RO set index can be set to initialize when the RO set index becomes 8. Alternatively, in addition to always initializing the RO set index when the time period is reached, it can be set to restart from 1 when the ordering of the RO set index exceeds 8 within the time period. Alternatively, it can be defined that a new time period for initializing the RO set index is introduced. Specifically, the new time period can be independently defined for each specific repetition number, and the terminal can determine a time period in which up to 8 RO set indices can be configured for each specific SSB beam index.

[0183] Alternatively, the RO set index can be set to be initialized every “time period” consisting of multiple association pattern periods, but the terminal can set / define the actual RO set index value to correspond to the value indicated by the base station through the PRACH mask index through a modular 8 operation. In other words, if the value set / indicated by the base station through the PRACH mask index is RO set index A, the terminal can be set to understand that the RO set indexes corresponding to the following [Mathematical Formula 1] have been selected. Thereafter, the terminal can be set to perform CFRA using any RO set index among the multiple RO set indexes set / indicated by the base station. The following [Mathematical Formula 1] is for the case where the RO set index is defined to start from 1. (If the RO set index is defined to start from 0, the corresponding mathematical formula can be applied as (RO set index) mod 8 = A.)

[0184]

[0185]

[0186]

[0187] For example, if A=1, the terminal can understand that RO set indexes 1, 9, 17, etc. are selected. As another example, if A=4, the terminal can understand that RO set indexes 4, 12, 20, etc. are selected. As another example, if A=8, the terminal can understand that RO set indexes 8, 16, 24, etc. are selected. Specifically, if every even RO set or every odd RO set or all RO sets are indicated, the terminal can be configured to understand as indicated by the base station without modular operation.

[0188] Meanwhile, it can be set that RO set index ordering starts from an RO set index that is a specific timing away from the time when a PRACH mask index-related instruction is received from the base station or the time when a CFRA-related instruction is received.

[0189]

[0190] 2. How to set the RA Type and / or number of repetitions when PRACH repetitions are used in CFRA.

[0191] Meanwhile, when PRACH single transmission is used in the existing CFRA, the RA type (2-step RACH or 4-step RACH) is set by the dedicated RACH configuration. Looking at RACH-ConfigDedicated in 38.311, the parameters 'cfra' and 'cfra-Two-Step' are defined, and by defining that the two parameters are not indicated from the base station at the same time, the RA type of the CFRA for a specific terminal can be set as 2-step RACH or 4-step RACH.

[0192]

[0193] [RACH-ConfigDedicated in Chapter 6.3.2 of 3GPP TS 38.331]

[0194] - RACH-ConfigDedicated

[0195] IE RACH-ConfigDedicated is used to specify the dedicated random access parameters.

[0196] [RACH-ConfigDedicated information element]

[0197] -- ASN1START

[0198] -- TAG-RACH-CONFIGDEDICATED-START

[0199] RACH-ConfigDedicated ::= SEQUENCE {

[0200] cfra CFRA OPTIONAL, -- Need S

[0201] ra-Prioritization RA-Prioritization OPTIONAL, -- Need N

[0202] ...,

[0203] [[

[0204] ra-PrioritizationTwoStep-r16 RA-Prioritization OPTIONAL, -- Need N

[0205] cfra-TwoStep-r16 CFRA-TwoStep-r16 OPTIONAL -- Need S

[0206] ]]

[0207] }

[0208]

[0209] [RACH-ConfigDedicated field descriptions]

[0210] cfra: Parameters for contention-free random access to a given target cell. If this field and cfra-TwoStep are absent, the UE performs contention-based random access.

[0211] cfra-TwoStep: Parameters for contention-free 2-step random access type to a given target cell. The network ensures that cfra and cfra-TwoStep are not configured at the same time. If this field and cfra are absent, the UE performs contention-based random access. This field may only be present if msgA-ConfigCommon is configured on the BWP.

[0212]

[0213] If PRACH repeated transmission is also applied to CFRA, it is necessary to distinguish whether the repeatedly transmitted CFRA is a 2-step RACH or a 4-step RACH, or whether the CFRA is repeated transmission or not, through a method similar to the above.

[0214]

[0215] (1) Proposed method 1: A method of introducing a new parameter that indicates the repetition factor

[0216] As a first proposed method, a method of introducing a new parameter that sets / indicates the repetition number in RACH-ConfigDedicated can be considered. For example, a new parameter indicating the repetition factor, such as ra-RepetitionFactor, can be introduced in RACH-ConfigDedicated, and the parameter can be set to indicate one of {2, 4, 8}. If the base station sets one of {2, 4, 8}, the terminal can determine that the CFRA has been instructed to be performed through repeated transmission, and in addition, (as in the existing operation), depending on the parameter set / indicated by the base station among 'cfra' and 'cfra-Two-Step', the terminal can determine whether to perform the CFRA repeated transmission as 4-step RACH (RA_TYPE = 4-stepRA) or 2-step RACH (RA_TYPE = 2-stepRA). On the other hand, if the base station does not set / indicate a parameter indicating a repetition factor such as ra-RepetitionFactor, the terminal can determine that it has been instructed to perform CFRA through a single transmission as before. Of course, in this case as well, the terminal can decide whether to perform CFRA single transmission as 4-step RACH (RA_TYPE = 4-stepRA) or 2-step RACH (RA_TYPE = 2-stepRA) depending on the parameter set / indicated by the base station as before.

[0217] Additionally, a parameter indicating a repetition factor such as ra-RepetitionFactor can be defined to indicate {1, 2, 4, 8}, in which case the terminal can understand and operate that the base station has set / instructed to perform CFRA as a single transmission by indicating the parameter value as 1.

[0218]

[0219] (2) Proposed method 2: A method of introducing parameters that indicate repeated transmission for each RA type.

[0220] As a second proposed method, a method of introducing new parameters indicating 2-step RACH repetition transmission and 4-step RACH repetition transmission in RACH-ConfigDedicated can be considered. For example, a new parameter 'cfra-repetition' indicating 4-step RACH repetition transmission and a new parameter 'cfra-TwoStep-repetition' indicating 2-step RACH repetition transmission can be introduced. When new parameters are introduced in this way, the base station can be defined to indicate only one of the four parameters (cfra, cfra-TwoStep, cfra-repetition, cfra-TwoStep-repetiton). In other words, two or more parameters can be defined so that they are not set at the same time. Thereafter, the terminal can be configured to perform CFRA using the parameter indicated by the base station among the four parameters. If none of the four parameters are indicated, the terminal can be configured to perform CBRA.

[0221] Additionally, when a parameter indicating 4-step RACH repetitive transmission or a parameter indicating 2-step RACH repetitive transmission is indicated, the base station needs to set / indicate the actual repetition factor. For example, a parameter indicating the repetition factor can be additionally introduced and set / indicated to one of {2, 4, 8}. As another example, the parameter indicating 4-step RACH repetitive transmission or the parameter indicating 2-step RACH repetitive transmission itself can be defined as a parameter indicating one of {2, 4, 8}. That is, when the base station indicates one of the parameters indicating 4-step RACH repetitive transmission or 2-step RACH repetitive transmission and sets / indicates one of {2, 4, 8}, the terminal can be configured to select either 4-step RACH or 2-step RACH depending on the indicated parameter type and perform CFRA repetitive transmission using the indicated parameter value as the repetition factor.

[0222]

[0223] (3) Proposed Method 3: A method in which the UE uses the same behavior used in past CBRA transmissions for CFRA transmissions.

[0224] As a third proposed method, we can consider a method in which whether to repeat the CFRA can be determined based on whether a PRACH single transmission or PRACH repeated transmission was used for the immediately preceding CBRA transmission, based on the time point at which a CFRA is triggered for a specific UE. Specifically, if a PRACH single transmission was used for the immediately preceding CBRA transmission for a specific UE, the CFRA can be defined to be performed as a PRACH single transmission as well. Alternatively, if a PRACH repeated transmission was used for the immediately preceding CBRA transmission for a specific UE, the CFRA can be defined to be performed as a PRACH repeated transmission as well. Consequently, from the perspective of a specific UE, the PRACH operation performed for the most recent CBRA can be configured to be applied to the CFRA operation that is triggered until the next CBRA is performed. In a slightly different method, if a specific UE successfully completes the initial access procedure and enters connected mode, the number of PRACH transmissions (i.e., single transmission or repeated transmission) used during the initial access procedure can be configured to be applied to the CFRA operation.

[0225] Additionally, the proposed method can be configured to be used if CFRA is enabled / instructed to be used in a dedicated PRACH configuration according to the existing 3GPP specification operation.

[0226]

[0227] 3. How to set timing when PRACH repeat transmission is used in CFRA

[0228] Section 8.1 of 3GPP TS 38.213 defines the timing gap of the RO that the base station can select when the RACH procedure is initiated by a PDCCH order. That is, the interval between the last symbol of the PDCCH order reception and the first symbol of the RO must be greater than the predefined timing gap.

[0229]

[0230] [Chapter 8.1 in 3GPP TS 38.213]

[0231] When the random access procedure is initiated by a PDCCH command, if there is a request from the upper layer, the UE transmits a PRACH at the selected PRACH opportunity as described in [11, TS 38.321]. The time between the last symbol of the PDCCH command reception and the first symbol of the PRACH transmission is greater than or equal to Here, (If a random access procedure is initiated by a PDCCH order, the UE, if requested by higher layers, transmits a PRACH in the selected PRACH occasion, as described in [11, TS 38.321], for which a time between the last symbol of the PDCCH order reception and the first symbol of the PRACH transmission is larger than or equal to , where )

[0232] - N T,2is the duration of N2 symbols corresponding to the PUSCH preparation time for UE processing capability 1 [6, TS 38.214], and μ is assumed to correspond to the smallest SCS configuration among the SCS configuration of the PDCCH command and the SCS configuration of the corresponding PRACH transmission. (N T,2 is a time duration of N2symbols corresponding to a PUSCH preparation time for UE processing capability 1 [6, TS 38.214] assuming μ corresponds to the smallest SCS configuration between the SCS configuration of the PDCCH order and the SCS configuration of the corresponding PRACH transmission)

[0233] - Active UL BWP remains unchanged If defined in [10, TS 38.133] is. Otherwise, ( if the active UL BWP does not change and is defined in [10, TS 38.133] otherwise )

[0234] - For FR1 =0.5msec, and for FR2 =0.25msec. ( =0.5 msec for FR1 and =0.25 msec for FR2)

[0235] - T switch is the switching gap period defined in [6, TS 38.214]. (T switch is a switching gap duration as defined in [6, TS 38.214])

[0236]

[0237] If PRACH repeated transmission is used in CFRA (i.e., RACH procedure started with PDCCH order), it is necessary to define which of the multiple ROs that the UE will use when performing repeated transmission with CFRA should satisfy the above timing gap. For example, it can be defined that the first symbol of the first (starting) RO among the multiple ROs that the UE will use is spaced from the last symbol of the PDCCH order reception by a predefined timing gap greater than or equal to the timing gap. That is, if the above example is reflected in Section 8.1 of the 38.213 spec, it is as follows.

[0238]

[0239] [Chapter 8.1 in 3GPP TS 38.213: Underlined portions are those proposed in this disclosure]

[0240] When the random access procedure is initiated by a PDCCH command, if there is a request from the upper layer, the UE transmits a PRACH at the selected PRACH opportunity as described in [11, TS 38.321]. The time between the last symbol of the PDCCH command reception and the first symbol of the first PRACH transmission is greater than or equal to Here, (If a random access procedure is initiated by a PDCCH order, the UE, if requested by higher layers, transmits a PRACH in the selected PRACH occasion, as described in [11, TS 38.321], for which a time between the last symbol of the PDCCH order reception and the first symbol of the firstPRACH transmission is larger than or equal to , where )

[0241] - N T,2 is the duration of N2 symbols corresponding to the PUSCH preparation time for UE processing capability 1 [6, TS 38.214], and μ is assumed to correspond to the smallest SCS configuration among the SCS configuration of the PDCCH command and the SCS configuration of the corresponding PRACH transmission. (N T,2 is a time duration of N2symbols corresponding to a PUSCH preparation time for UE processing capability 1 [6, TS 38.214] assuming μ corresponds to the smallest SCS configuration between the SCS configuration of the PDCCH order and the SCS configuration of the corresponding PRACH transmission)

[0242] - Active UL BWP remains unchanged If defined in [10, TS 38.133] is. Otherwise, ( if the active UL BWP does not change and is defined in [10, TS 38.133] otherwise )

[0243] - For FR1 =0.5msec, and for FR2 =0.25msec. ( =0.5 msec for FR1 and =0.25 msec for FR2)

[0244] - T switch is the switching gap period defined in [6, TS 38.214]. (T switch is a switching gap duration as defined in [6, TS 38.214])

[0245]

[0246] 4. Best beam indication method for Msg3 PUSCH re-transmission when different beams are available for PRACH retransmission

[0247] When different beams are available for PRACH repetitive transmission, the base station can configure / indicate the best UL beam index to the UE. In this case, in the case of the initial transmission of Msg3 PUSCH, the best UL beam index can be indicated through the RAR UL grant, but in the case of re-transmission of Msg3 PUSCH, the best UL beam index needs to be indicated separately. In this case, the bit width that can be considered for the best UL beam index can be K bits (K is a positive integer). If up to M different beam indices are configured / indicated to be used within specific RACH attempts performing PRACH repetitive transmission, can be determined. For example, if M is one of {2, 3}, K=1, if M is one of {4, 5, 6, 7}, K=2, and if M is one of {8, 9, ..., 14, 15}, K=3.

[0248] Specifically, a method of indicating the best UL beam index using a specific DCI field in the DCI (i.e., DCI format 0_0 CRC scrambled by TC-RNTI) indicating re-transmission of Msg3 PUSCH can be considered. As one method, K bits among the DCI fields defined as reserved can be used to indicate the best UL beam index. For example, since the HARQ process number field defined as a 4-bit field is not used for Msg3 PUSCH re-transmission and is defined as reserved, the whole or part of the HARQ process number field can be used to indicate the best UL beam index. If part of it is used, K bits from the LSB (or MSB) can be used, and the unused bits can be defined as reserved. Alternatively, the New data indicator field defined as a 1-bit field can be used to indicate the best UL beam index. Alternatively, the reserved fields can be used in combination. Alternatively, a new field with K bits can be introduced within the DCI (i.e., DCI format 0_0 CRC scrambled by TC-RNTI) to indicate the best UL beam index.

[0249]

[0250] Meanwhile, in a situation where PRACH repetition is used, the number M of different beam indices that can be used within a specific RACH attempts may be applied equally to CBRA and / or CFRA, but different methods may be applied depending on whether it is CBRA or CFRA. First, in case of CBRA, since the base station does not know which UE transmits Msg3 PUSCH, if a specific “RO location” is indicated through RAR UL grant and / or DCI format 0_0 with CRC scrambled by TC-RNTI (e.g., reserved field), the UE may determine that the UL beam of the corresponding RO location is indicated as the best UL beam and may configure the UL beam used for PRACH transmission in the indicated RO to transmit Msg3 PUSCH. Next, in case of CFRA (same method as above, or) specific beams M can be set / mapped in advance to the terminal for PRACH transmission for CFRA operation from index 0 to M-1, and a specific “beam index” to be used for Msg3 PUSCH transmission can be directly indicated to the terminal via RAR UL grant and / or DCI format 0_0 with CRC scrambled by TC-RNTI (e.g., reserved field). The terminal can receive the information and be set to transmit Msg3 PUSCH using the best UL beam index.

[0251]

[0252] When the base station sets / indicates the best UL beam index, the terminal can use the UL beam index for Msg3 PUSCH (re-)transmission, and further, can use the UL beam index for Msg4 HARQ-ACK PUCCH transmission.

[0253]

[0254] The above proposed method can be set / applied to other UL signals / channels such as PRACH / PUSCH / PUCCH. In addition, it is clear that examples of the proposed method described above can also be included as one of the implementation methods of the present specification, and thus can be considered as a type of proposed method. In addition, the proposed methods described above can be implemented independently, but can also be implemented in the form of a combination (or merge) of some of the proposed methods. Information on whether the proposed methods are applied (or information on the rules of the proposed methods) can be defined as a rule so that the base station notifies the terminal of the application of the proposed methods through a predefined signal (e.g., a physical layer signal or a higher layer signal). The higher layer can include one or more of functional layers such as MAC, RLC, PDCP, RRC, and SDAP, for example.

[0255]

[0256] The methods, embodiments or descriptions for implementing the method proposed in this specification may be applied separately, or one or more methods (or embodiments or descriptions) may be applied in combination.

[0257]

[0258] [Terminal claim related explanation]

[0259] The embodiments described below are specifically described with reference to FIG. 5 in terms of the operation of a user equipment (UE). The methods described below are distinguished for convenience of explanation, and it is understood that, unless mutually exclusive, some components of one method may be substituted for or combined with some components of another method.

[0260] FIG. 5 is a diagram illustrating an example of the operation process of a terminal in a system applicable to the present disclosure.

[0261] In step S510, the user equipment (UE) transmits a preamble of a contention free random access (CFRA) procedure to the base station (BS).

[0262] In step S520, the terminal receives a random access response (RAR) of the CFRA procedure from the base station.

[0263] In step S530, the terminal transmits a PUSCH (physical uplink shared channel) including Msg3 (message 3) of the CFRA procedure to the base station based on the first beam indicated by the RAR.

[0264] At step S540, the terminal receives DCI format 0_0 (downlink control information format 0_0) indicating retransmission for the PUSCH from the base station.

[0265] At step S550, the terminal performs the retransmission for the PUSCH based on the second beam indicated by the DCI format 0_0.

[0266]

[0267] According to various embodiments of the present disclosure, the second beam may be indicated by all or part of the first bits included in a hybrid automatic repeat request (HARQ) process number field included in the DCI format 0_0.

[0268] According to various embodiments of the present disclosure, the second beam may be indicated by a number of bits set from the least significant bit (LSB) or the most significant bit (MSB) of the first bits.

[0269] According to various embodiments of the present disclosure, the second beam may be indicated by a specific field including one bit or a specific number of bits within the DCI format 0_0.

[0270] According to various embodiments of the present disclosure, the first beam and the second beam may be included in a plurality of beams associated with repeated transmissions of the preamble.

[0271] According to various embodiments of the present disclosure, each of the repeated transmissions of the preamble may be based on a different beam among the plurality of beams.

[0272] According to various embodiments of the present disclosure, the embodiment of FIG. 5 may further include a step of receiving configuration information related to a repetition number of the CFRA procedure. The preamble may be repeatedly transmitted to the base station within the repetition number.

[0273]

[0274] According to various embodiments of the present disclosure, a terminal is provided in a wireless communication system. The terminal includes a transceiver and at least one processor, wherein the at least one processor may be configured to perform the operating method of the terminal according to FIG. 5.

[0275]

[0276] According to various embodiments of the present disclosure, a device for controlling a terminal in a communication system is provided. The device includes at least one processor and at least one memory operably connected to the at least one processor. The at least one memory may be configured to store instructions for performing the operating method of the terminal according to FIG. 5 based on instructions executed by the at least one processor.

[0277]

[0278] According to various embodiments of the present disclosure, one or more non-transitory computer-readable media (CRM) storing one or more commands are provided. The one or more commands, when executed by one or more processors, perform operations, and the operations may include the operating method of the terminal according to FIG. 5.

[0279]

[0280] [Explanation regarding base station claims]

[0281] The embodiments described below are specifically described with reference to FIG. 6 from the perspective of the operation of a base station (BS). The methods described below are distinguished for convenience of explanation, and it is understood that some components of one method may be substituted for or combined with some components of another method, as long as they are not mutually exclusive.

[0282] FIG. 6 is a diagram illustrating an example of an operation process of a base station in a system applicable to the present disclosure.

[0283] At step S610, the base station (BS) receives a preamble of a contention free random access (CFRA) procedure from a user equipment (UE).

[0284] At step S620, the base station transmits a random access response (RAR) of the CFRA procedure to the terminal.

[0285] At step S630, the base station receives a PUSCH (physical uplink shared channel) including Msg3 (message 3) of the CFRA procedure from the terminal based on the first beam indicated by the RAR.

[0286] At step S640, the base station transmits DCI format 0_0 (downlink control information format 0_0) to the terminal, which instructs retransmission for the PUSCH.

[0287] At step S650, the base station receives the retransmission for the PUSCH based on the second beam indicated by the DCI format 0_0.

[0288]

[0289] According to various embodiments of the present disclosure, the second beam may be indicated by all or part of the first bits included in a hybrid automatic repeat request (HARQ) process number field included in the DCI format 0_0.

[0290] According to various embodiments of the present disclosure, the second beam may be indicated by a number of bits set from the least significant bit (LSB) or the most significant bit (MSB) of the first bits.

[0291] According to various embodiments of the present disclosure, the second beam may be indicated by a specific field including one bit or a specific number of bits within the DCI format 0_0.

[0292] According to various embodiments of the present disclosure, the first beam and the second beam may be included in a plurality of beams associated with repeated transmissions of the preamble.

[0293] According to various embodiments of the present disclosure, each of the repeated transmissions of the preamble may be based on a different beam among the plurality of beams.

[0294] According to various embodiments of the present disclosure, the embodiment of FIG. 6 may further include a step of receiving configuration information related to a repetition number of the CFRA procedure. The preamble may be repeatedly transmitted to the base station within the repetition number.

[0295]

[0296] According to various embodiments of the present disclosure, a base station is provided in a wireless communication system. The base station includes a transceiver and at least one processor, wherein the at least one processor may be configured to perform the operating method of the base station according to FIG. 6.

[0297]

[0298] According to various embodiments of the present disclosure, a device for controlling a base station in a wireless communication system is provided. The device includes at least one processor and at least one memory operably connected to the at least one processor. The at least one memory may be configured to store instructions for performing the operating method of the base station according to FIG. 6 based on instructions executed by the at least one processor.

[0299]

[0300] According to various embodiments of the present disclosure, one or more non-transitory computer-readable media (CRM) storing one or more commands are provided. The one or more commands, when executed by one or more processors, perform operations, and the operations may include the operating method of the base station according to FIG. 6.

[0301]

[0302] Wireless devices applicable to the present disclosure

[0303] Below, examples of wireless devices to which various embodiments of the present disclosure are applied are described.

[0304] FIG. 7 is a drawing showing an example of the structure of a first device and a second device in a system applicable to the present disclosure.

[0305] The first device (1600) may include a processor (1610), an antenna unit (1620), a transceiver (1630), and a memory (1640).

[0306] The processor (1610) performs baseband-related signal processing and may include a higher layer processing unit (1611) and a physical layer processing unit (1615). The higher layer processing unit (1611) may process operations of a MAC layer, an RRC layer, or higher layers. The physical layer processing unit (1615) may process operations of a PHY layer. For example, when the first device (1600) is a base station device in base station-to-terminal communication, the physical layer processing unit (1615) may perform uplink reception signal processing, downlink transmission signal processing, etc. For example, when the first device (1600) is a first terminal device in terminal-to-terminal communication, the physical layer processing unit (1615) may perform downlink reception signal processing, uplink transmission signal processing, sidelink transmission signal processing, etc. In addition to performing baseband-related signal processing, the processor (1610) may also control the overall operation of the first device (1600).

[0307] The antenna unit (1620) may include one or more physical antennas, and when it includes multiple antennas, it may support MIMO transmission and reception. The transceiver (1630) may include an RF (Radio Frequency) transmitter and an RF receiver. The memory (1640) may store information processed by the processor (1610), and software, an operating system, applications, etc. related to the operation of the first device (1600), and may also include components such as a buffer.

[0308] The processor (1610) of the first device (1600) may be configured to implement the operation of the base station in the base station-to-terminal communication (or the operation of the first terminal device in the terminal-to-terminal communication) in the embodiments described in the present disclosure.

[0309]

[0310] The second device (1650) may include a processor (1660), an antenna unit (1670), a transceiver (1680), and a memory (1690).

[0311] The processor (1660) performs baseband-related signal processing and may include a higher layer processing unit (1661) and a physical layer processing unit (1665). The higher layer processing unit (1661) may process operations of a MAC layer, an RRC layer, or higher layers. The physical layer processing unit (1665) may process operations of a PHY layer. For example, when the second device (1650) is a terminal device in base station-terminal communication, the physical layer processing unit (1665) may perform downlink reception signal processing, uplink transmission signal processing, etc. For example, when the second device (1650) is a second terminal device in terminal-to-terminal communication, the physical layer processing unit (1665) may perform downlink reception signal processing, uplink transmission signal processing, sidelink reception signal processing, etc. In addition to performing baseband-related signal processing, the processor (1660) may also control the overall operation of the second device (1660).

[0312] The antenna unit (1670) may include one or more physical antennas, and when including multiple antennas, may support MIMO transmission and reception. The transceiver (1680) may include an RF transmitter and an RF receiver. The memory (1690) may store information processed by the processor (1660), and software, an operating system, applications, etc. related to the operation of the second device (1650), and may also include components such as a buffer.

[0313] The processor (1660) of the second device (1650) may be configured to implement operations of the terminal in base station-to-terminal communication (or operations of the second terminal device in terminal-to-terminal communication) in the embodiments described in the present disclosure.

[0314] In the operation of the first device (1600) and the second device (1650), the same explanations given for the base station and the terminal (or the first terminal and the second terminal in the terminal-to-terminal communication) in the examples of the present disclosure may be applied, and any duplicate explanations are omitted.

[0315]

[0316] Here, the wireless communication technology implemented in the device (1600, 1650) of the present disclosure may include various other wireless communication technologies as well as LTE, NR, and 6G.

[0317]

[0318] The claims described in the various embodiments of the present disclosure may be combined in various ways. For example, the technical features of the method claims of the various embodiments of the present disclosure may be combined and implemented as a device, and the technical features of the device claims of the various embodiments of the present disclosure may be combined and implemented as a method. Furthermore, the technical features of the method claims of the various embodiments of the present disclosure may be combined and implemented as a device, and the technical features of the method claims of the various embodiments of the present disclosure may be combined and implemented as a method.

Claims

1. In a method of operating a terminal (user equipment, UE) in a wireless communication system, A step of transmitting a preamble of a contention free random access (CFRA) procedure to a base station (BS); A step of receiving a RAR (random access response) of the CFRA procedure from the base station; A step of transmitting a PUSCH (physical uplink shared channel) including Msg3 (message 3) of the CFRA procedure to the base station based on the first beam indicated by the RAR; A step of receiving DCI format 0_0 (downlink control information format 0_0) indicating retransmission of the PUSCH from the base station; Comprising a step of performing the retransmission for the PUSCH based on the second beam indicated by the DCI format 0_0, method.

2. In paragraph 1, The second beam is indicated by all or part of the first bits included in the HARQ (hybrid automatic repeat request) process number field included in the DCI format 0_0. method.

3. In paragraph 2, The second beam is indicated by a number of bits set from the least significant bit (LSB) or the most significant bit (MSB) of the first bits. method.

4. In paragraph 1, The second beam is indicated by a specific field containing one bit or a specific number of bits in the DCI format 0_0. method.

5. In paragraph 1, The first beam and the second beam are included in a plurality of beams associated with repeated transmissions of the preamble, method.

6. In paragraph 5, Each of the repeated transmissions of the above preamble is based on a different beam among the plurality of beams, method.

7. In paragraph 1, Further comprising a step of receiving setup information related to the repetition number of the above CFRA procedure, The above preamble is repeatedly transmitted to the base station within the repetition number. method.

8. In a method of operating a base station (BS) in a wireless communication system, A step of receiving a preamble of a contention free random access (CFRA) procedure from a user equipment (UE); A step of transmitting a RAR (random access response) of the CFRA procedure to the terminal; A step of receiving a PUSCH (physical uplink shared channel) including Msg3 (message 3) of the CFRA procedure from the terminal based on the first beam indicated by the RAR; A step of transmitting DCI format 0_0 (downlink control information format 0_0) instructing the terminal to retransmit the PUSCH; A step of receiving the retransmission for the PUSCH based on the second beam indicated by the DCI format 0_0, method.

9. In paragraph 8, The second beam is indicated by all or part of the first bits included in the HARQ (hybrid automatic repeat request) process number field included in the DCI format 0_0. method.

10. In paragraph 9, The second beam is indicated by a number of bits set from the least significant bit (LSB) or the most significant bit (MSB) of the first bits. method.

11. In paragraph 8, The second beam is indicated by a specific field containing one bit or a specific number of bits in the DCI format 0_0. method.

12. In paragraph 8, The first beam and the second beam are included in a plurality of beams associated with repeated transmissions of the preamble, method.

13. In paragraph 12, Each of the repeated transmissions of the above preamble is based on a different beam among the plurality of beams, method.

14. In paragraph 8, Further comprising a step of receiving setup information related to the repetition number of the above CFRA procedure, The above preamble is repeatedly transmitted to the base station within the repetition number. method.

15. In a wireless communication system, at a terminal, Transmitter and receiver; at least one processor; and At least one memory operably connectable to said at least one processor and storing instructions that, when executed by said at least one processor, perform operations; The above actions are, Comprising all steps of the method according to any one of claims 1 to 7, Terminal.

16. In a wireless communication system, at a base station, Transmitter and receiver; at least one processor; and At least one memory operably connectable to said at least one processor and storing instructions that, when executed by said at least one processor, perform operations; The above actions are, Comprising all steps of the method according to any one of claims 8 to 14, Base station.

17. In a control device that controls a terminal in a wireless communication system, at least one processor; and comprising at least one memory operably connected to at least one of the processors; The at least one memory stores instructions for performing operations based on being executed by the at least one processor, The above actions are, Comprising all steps of the method according to any one of claims 1 to 7, controller.

18. In a control device for controlling a base station in a wireless communication system, at least one processor; and comprising at least one memory operably connected to at least one of the processors; The at least one memory stores instructions for performing operations based on being executed by the at least one processor, The above actions are, Comprising all steps of the method according to any one of claims 8 to 14, controller.

19. In one or more non-transitory computer-readable media storing one or more instructions, The one or more instructions perform operations based on being executed by one or more processors, The above actions are, Comprising all steps of the method according to any one of claims 1 to 7, Computer readable medium.

20. In one or more non-transitory computer-readable media storing one or more instructions, The one or more instructions perform operations based on being executed by one or more processors, The above actions are, Comprising all steps of the method according to any one of claims 8 to 14, Computer readable medium.

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