Method and device for transmitting and receiving random access channel

Abstract

A method according to an embodiment of the present specification comprises the steps of: receiving a RACH configuration; and transmitting a PRACH on the basis of sets. Each of the sets includes PRACH occasions based on the number of repetitions. The sets include a first set and a second set associated with frequency hopping. The first set and the second set are determined on the basis of an order of a time resource index and / or a frequency resource index of a first PRACH occasion in each set among sets in a time period.

Description

Method and device for transmitting and receiving on a random access channel

[0001] The present specification relates to a method and device for transmitting and receiving a random access channel.

[0002] Mobile communication systems were developed to provide voice services while ensuring user activity. However, they have expanded beyond voice to include data services. Currently, explosive growth in traffic is leading to resource shortages and users are demanding faster services, necessitating a more advanced mobile communication system.

[0003] Next-generation mobile communication systems must support explosive data traffic growth, dramatically increasing data rates per user, a vastly increased number of connected devices, ultra-low end-to-end latency, and high energy efficiency. To achieve these goals, various technologies are being studied, including dual connectivity, massive multiple input multiple output (MIMO), in-band full duplex, non-orthogonal multiple access (NOMA), super wideband support, and device networking.

[0004] Meanwhile, in Rel-18, PRACH repeated transmission using ROs (PRACH Occasions) was introduced to improve coverage.

[0005] For PRACH repeat transmission, the number of repetitions (e.g. ) can be set. The ROs based on the above repetition count are consecutive in the time domain and use the same frequency resource. As a specific example, each set for PRACH repeated transmission is consecutive in the time domain within the same frequency resource. It is determined to include the ROs of the dog. At this time, the set(s) within the time interval are defined / determined based on the first RO of the set.

[0006] As described above, according to the current standard, PRACH repeated transmission is performed based on ROs having the same frequency resource index.

[0007] The purpose of this specification is to propose a method for supporting frequency hopping in PRACH repetitive transmissions. More specifically, the purpose of this specification is to propose a method for supporting frequency hopping while minimizing changes to the previously defined rules for determining the set(s) of ROs associated with PRACH repetitive transmissions.

[0008] The purpose of this specification is to propose a method to solve the above-mentioned problems.

[0009] The technical problems to be achieved in this specification 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 invention belongs from the description below.

[0010] A method performed by a terminal according to one embodiment of the present disclosure includes the steps of receiving a random access channel (RACH) configuration and transmitting a physical random access channel (PRACH) based on the sets.

[0011] Each of the above sets contains PRACH occasions based on the number of repetitions.

[0012] The above sets include a first set and a second set related to frequency hopping.

[0013] The first set and the second set are characterized in that they are determined based on the order of the time resource index and / or the frequency resource index of the first PRACH occasion within each set among the sets within a time period.

[0014] The second set may be determined in ascending order of the time resource index from the first set having the lowest frequency resource index among the sets within the time interval.

[0015] Based on the fact that there is no set based on the time resource index greater than the time resource index based on the first set among the above sets:

[0016] The second set can be determined in ascending order of the frequency resource index from the first set.

[0017] The frequency hopping may be performed based on i) a first PRACH occasion selected from the first set or the second set and ii) a second PRACH occasion selected from the second set or the first set.

[0018] The second PRACH occasion may be located after the first PRACH occasion in the time domain.

[0019] The above sets may include i) the first set and the second set and / or ii) the third set.

[0020] The third set may include the PRACH occasions associated with the frequency hopping.

[0021] The frequency hopping associated with the third set may be performed based on indices associated with the number of repetitions.

[0022] In the third set, a frequency resource index of a PRACH occasion based on one of the indices may be different from a frequency resource index of a PRACH occasion based on a next index of the indices.

[0023] The method may further include a step of receiving a System Information Block (SIB). The SIB may include settings related to the frequency hopping.

[0024] The above settings related to the frequency hopping may include i) information indicating whether the frequency hopping is enabled, ii) information related to determination of the first set and the second set, and / or iii) information related to determination of a PRACH occasion for the frequency hopping.

[0025] A terminal according to another embodiment of the present disclosure includes one or more transceivers, one or more processors, and one or more memories connected to the one or more processors and storing instructions.

[0026] The instructions are characterized in that, based on being executed by the one or more processors, the one or more processors are set to perform all steps of any one of the methods.

[0027] A device according to another embodiment of the present disclosure comprises one or more memories and one or more processors functionally connected to the one or more memories.

[0028] Said one or more memories are characterized in that they store instructions that cause said one or more processors to perform all steps of any one of said methods based on what is executed by said one or more processors.

[0029] In another embodiment of the present disclosure, one or more non-transitory computer-readable media store instructions, the instructions being executable by one or more processors, characterized in that they cause the one or more processors to perform all steps of any one of the methods.

[0030] A method performed by a base station according to another embodiment of the present disclosure includes the steps of transmitting a random access channel (RACH) configuration and receiving a physical random access channel (PRACH) based on the sets.

[0031] Each of the above sets contains PRACH occasions based on the number of repetitions.

[0032] The above sets include a first set and a second set related to frequency hopping.

[0033] The first set and the second set are characterized in that they are determined based on the order of the time resource index and / or the frequency resource index of the first PRACH occasion within each set among the sets within a time period.

[0034] According to another embodiment of the present disclosure, a base station includes one or more transceivers, one or more processors, and one or more memories coupled to the one or more processors and storing instructions.

[0035] The instructions are characterized in that they are executed by the one or more processors, and the one or more processors are set to perform all steps of the method.

[0036] According to the embodiments of the present specification, the frequency location is changed for each RO for PRACH repeated transmission. Therefore, a frequency diversity gain can be obtained compared to the existing PRACH repeated transmission operation performed based on ROs having the same frequency resource index.

[0037] Furthermore, according to the embodiments of the present disclosure, sets for frequency hopping are determined based on the order of the time resource index and / or frequency resource index of the first RO within each set among the sets within a time interval. Therefore, changes to existing rules defined for determining the set(s) of ROs associated with PRACH repeated transmission (e.g., determination based on the first RO of each set) can be minimized. In other words, the implementation complexity of the terminal / base station required to support PRACH repeated transmission together with frequency hopping can be minimized.

[0038] The effects that can be obtained from this specification are not limited to the effects mentioned above, and other effects that are not mentioned can be clearly understood by a person having ordinary skill in the technical field to which this specification belongs from the description below.

[0039] Figure 1 illustrates physical channels and typical signal transmission used in a 3GPP system.

[0040] Figure 2 shows RACH occasions by preamble format.

[0041] Figure 3 illustrates a random access procedure.

[0042] Figure 4 shows an example of an RO group for PRACH repetition.

[0043] Figure 5 shows another example of a RO group for PRACH repetition.

[0044] Figure 6 shows an example of an RO group according to method 1 of the present specification.

[0045] Figure 7 shows another example of an RO group according to method 1 of the present specification.

[0046] Figure 8 shows an example of an RO group according to method 2 of the present specification.

[0047] Figure 9 shows another example of an RO group according to method 2 of the present specification.

[0048] Figure 10 shows an example of an RO group according to method 3 of the present specification.

[0049] Figure 11 shows another example of an RO group according to method 3 of the present specification.

[0050] FIG. 12 illustrates a frequency hopping pattern according to one embodiment of the present specification.

[0051] FIG. 13 illustrates a frequency hopping pattern according to another embodiment of the present specification.

[0052] FIG. 14 illustrates pairing of P RO groups according to one embodiment of the present specification.

[0053] FIG. 15 illustrates an example of a frequency hopping pattern based on P RO groups according to one embodiment of the present specification.

[0054] FIG. 16 illustrates another example of a frequency hopping pattern based on P RO groups according to one embodiment of the present specification.

[0055] FIG. 17 is a flowchart illustrating a method performed by a terminal according to one embodiment of the present specification.

[0056] FIG. 18 is a flowchart illustrating a method performed by a base station according to another embodiment of the present specification.

[0057] FIG. 19 is a drawing showing the configuration of the first device and the second device according to an embodiment of the present specification.

[0058] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The detailed description set forth below, together with the accompanying drawings, is intended to illustrate exemplary embodiments of the present invention and is not intended to represent the only embodiments in which the present invention may be practiced. The following detailed description includes specific details to provide a thorough understanding of the present invention. However, one of ordinary skill in the art will appreciate that the present invention may be practiced without these specific details.

[0059] In some cases, to avoid obscuring the concept of the present invention, well-known structures and devices may be omitted or illustrated in block diagram form focusing on the core functions of each structure and device.

[0060] Hereinafter, downlink (DL) refers to communication from a base station to a terminal, and uplink (UL) refers to communication from a terminal to a base station. In downlink, a transmitter may be part of a base station, and a receiver may be part of a terminal. In uplink, a transmitter may be part of a terminal, and a receiver may be part of a base station. A base station may be expressed as a first communication device, and a terminal may be expressed as a second communication device. A base station (BS) may be replaced by terms such as a fixed station, Node B, eNB (evolved-NodeB), gNB (Next Generation NodeB), BTS (base transceiver system), access point (AP: Access Point), network (5G network), AI system, RSU (road side unit), vehicle, robot, drone (Unmanned Aerial Vehicle, UAV), AR (Augmented Reality) device, VR (Virtual Reality) device, etc. In addition, the terminal may be fixed or mobile, and may be replaced with terms such as UE (User Equipment), MS (Mobile Station), UT (user terminal), MSS (Mobile Subscriber Station), SS (Subscriber Station), AMS (Advanced Mobile Station), WT (Wireless terminal), MTC (Machine-Type Communication) device, M2M (Machine-to-Machine) device, D2D (Device-to-Device) device, vehicle, robot, AI module, drone (Unmanned Aerial Vehicle, UAV), AR (Augmented Reality) device, VR (Virtual Reality) device, etc.

[0061] Physical channels and general signal transmission

[0062] 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.

[0063] When a terminal is powered on or enters a new cell, it performs an initial cell search operation, such as synchronizing with the base station (S101). To this end, the terminal receives a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS) from the base station to synchronize with the base station and obtain information such as a cell ID. Afterwards, the terminal can receive a Physical Broadcast Channel (PBCH) from the base station to obtain broadcast information within the cell. Meanwhile, the terminal can receive a Downlink Reference Signal (DL RS) during the initial cell search phase to check the downlink channel status.

[0064] A terminal that has completed initial cell search can obtain more specific system information by receiving a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) according to information carried in the PDCCH (S102).

[0065] Meanwhile, when accessing a base station for the first time or when there are no radio resources for signal transmission, the terminal may perform a random access procedure (RACH) for the base station (S103 to S106). To this end, the terminal may transmit a specific sequence as a preamble via a physical random access channel (PRACH) (S103 and S105) and receive a response message (RAR (Random Access Response) message) to the preamble via a PDCCH and a corresponding PDSCH. In the case of a contention-based RACH, a contention resolution procedure may additionally be performed (S106).

[0066] The terminal that has performed the procedure described above can then perform PDCCH / PDSCH reception (S107) and physical uplink shared channel (PUSCH) / physical uplink control channel (PUCCH) transmission (S108) as general uplink / downlink signal transmission procedures. In particular, the terminal can receive downlink control information (DCI) through the PDCCH. Here, the DCI includes control information such as resource allocation information for the terminal, and different formats can be applied depending on the purpose of use.

[0067] Meanwhile, the control information that the terminal transmits to the base station via the uplink or that the terminal receives from the base station may include downlink / uplink ACK / NACK signals, CQI (Channel Quality Indicator), PMI (Precoding Matrix Index), RI (Rank Indicator), etc. The terminal may transmit the above-described control information such as CQI / PMI / RI via PUSCH and / or PUCCH.

[0068] Next, let's look at the RACH slot.

[0069] A RACH slot contains one or more RACH Occasion(s).

[0070] The slot duration is 1ms for {1.25kHz, 5kHz} subcarrier spacing and has scalable duration (i.e. 1ms, 0.5ms, 0.25ms, 0.125ms) for {15kHz, 30kHz, 60kHz, 120kHz} subcarrier spacing.

[0071] For short preamble formats, the starting OFDM symbol index in the RACH slot has values ​​{0,2,x}.

[0072] Figure 2 shows RACH occasions by preamble format.

[0073] Referring to Fig. 2, a RACH slot may include one or more RACH occasions (ROs) for each preamble format (e.g., A1, A2, ..C2). Fig. 2 (a) shows a case where the start OFDM symbol is '0', and Fig. 2 (b) shows a case where the start OFDM symbol is '2'.

[0074] Figure 3 illustrates a random access procedure.

[0075] Figure 3 (a) shows a contention-based RACH procedure, and Figure 3 (b) shows a contention-free RACH procedure.

[0076] Below, we will look at MSG1 transmission.

[0077] Subcarrier spacing for MSG1 is set in the RACH configuration and provided in the handover command for contention-free RA procedures for handover.

[0078] Preamble indices for contention based random access (CBRA) and contention free random access (CFRA) are mapped consecutively to one SSB in one RACH transmission occasion.

[0079] CBRA: The association between a SS block (SSB) and a subset of RACH resources and / or preamble indices within an SS burst set is established by a parameter set in the RMSI.

[0080] CFRA: The UE may be configured to transmit multiple MSG1s via dedicated multi-RACH transmission opportunities in the time domain before the end of the monitored RAR window.

[0081] And, the association between CFRA preamble and SSB is reestablished via UE-specific RRC.

[0082] The random access procedure can be a Type-1 random access procedure (4-step RA) or a Type-2 random access procedure (2-step RA).

[0083] The above Type-1 random access procedure may include transmitting a random access preamble (Msg1) on a physical random access channel (PRACH), receiving a random access response (RAR) (Msg2), transmitting a PUSCH scheduled by an UL grant of the RAR (Msg3), and transmitting a PDSCH for contention resolution (Msg4). If the random access procedure is contention-free random access (CFRA), the Msg3 transmission and Msg4 reception operations are omitted.

[0084] The above Type-2 random access procedure may include transmission of a random access preamble and PUSCH (MsgA) and reception of a RAR (MsgB).

[0085] Settings / actions related to random access preambles

[0086] 8.1 Random access preamble

[0087] The physical random access procedure for a UE is triggered by a request for PRACH transmission from a higher layer or by a PDCCH order for a cell. Configuration by the higher layer for PRACH transmission includes:

[0088] - Configuration for PRACH transmission in a cell [4, TS 38.211].

[0089] - Preamble index, preamble SCS, , if applicable, may include the corresponding RA-RNTI [11, TS 38.321], and PRACH resources for the cell.

[0090] - When the UE transmits PRACH repeatedly, the number of preamble repetitions for PRACH transmission >1.

[0091] The UE transmits power as described in Section 7.4. Transmit PRACH in the cell using the selected PRACH format having In case of preamble repetition, the same spatial filter is used to determine the PRACH resource or Transmit from a set of resources.

[0092] For a Type-1 random access procedure, the UE is provided with N SS / PBCH block indices associated with one PRACH opportunity and R contention-based preambles per SS / PBCH block index per valid PRACH opportunity by ssb-perRACH-OccasionAndCB-PreamblesPerSSB.

[0093] For a Type-2 random access procedure using a common configuration of PRACH occasions with a Type-1 random access procedure, the UE is provided with the number N of SS / PBCH block indices associated with one PRACH occasion by ssb-perRACH-OccasionAndCB-PreamblesPerSSB and the number Q of contention-based preambles per SS / PBCH block index per valid PRACH opportunity by msgA-CB-PreamblesPerSSB-PerSharedRO. A PRACH transmission can be made in a subset of the PRACH opportunities associated with the same SS / PBCH block index within a SSB-RO mapping period for the UE provided with a PRACH mask index by msgA-SSB-SharedRO-MaskIndex according to [11, TS 38.321].

[0094] For a Type-2 random access procedure with a separate configuration of PRACH occasions from the Type-1 random access procedure, the UE is provided with the number of SS / PBCH block indices R per valid PRACH occasion and the number of SS / PBCH block indices N associated with one PRACH occasion by msgA-SSB-PerRACH-OccasionAndCB-PreamblesPerSSB, otherwise it receives ssb-perRACH-OccasionAndCB-PreamblesPerSSB.

[0095] For a random access procedure associated with a feature combination indicated by FeatureCombinationPreambles, the UE is provided with the number N of SS / PBCH block indices associated with one PRACH opportunity by ssb-perRACH-OccasionAndCB-PreamblesPerSSB or msgA-SSB-PerRACH-OccasionAndCB-PreamblesPerSSB, and with the number S of contention-based preambles per SS / PBCH block index per valid PRACH opportunity by startPreambleForThisPartition and numberOfPreamblesPerSSB-ForThisPartition. A PRACH transmission can be made in a subset of the PRACH opportunities associated with the same SS / PBCH block index within a SSB-RO mapping period for a UE provided with a PRACH mask index by ssb-SharedRO-MaskIndex according to [11, TS 38.321].

[0096] For a Type-1 random access procedure or a Type-2 random access procedure that separately configures a Type-1 random access procedure and a PRACH occasion, if N<1, one SS / PBCH block index is mapped to 1 / N consecutive valid PRACH occasions and R contention-based preambles, and R contention-based preambles with consecutive indices associated with the SS / PBCH block index per valid PRACH occasion start from preamble index 0. If N≥1, R contention-based preambles with consecutive indices associated with the SS / PBCH block index n (0≤n≤N-1) are mapped to preamble indexes per valid PRACH occasion. It starts from here is given in totalNumberOfRA-Preambles for type 1 random access procedures, or in msgA-TotalNumberOfRA-Preambles for type 2 random access procedures with separate configurations of type 1 random access procedures and PRACH opportunities, and is an integer multiple of N.

[0097] For a Type-2 random access procedure with a common structure of PRACH occasions and a Type-1 random access procedure, if N<1, one SS / PBCH block index is mapped to 1 / N consecutive valid PRACH occasions, and Q contention-based preambles having consecutive indices associated with the SS / PBCH block index per valid PRACH occasion, starting from preamble index R. If N≥1, Q contention-based preambles having consecutive indices associated with the SS / PBCH block index n (0≤n≤N-1) per valid PRACH occasion are mapped to preamble index R. It starts from here, here is provided in totalNumberOfRA-Preambles for Type-1 random access procedures.

[0098] The SS / PBCH block indices provided in ssb-PositionsInBurst of SIB1 or ServingCellConfigCommon are mapped to valid PRACH cases in the following order, where the parameters are described in [4, TS 38.211].

[0099] - First, the increasing order of preamble index within a single PRACH case

[0100] - Second, the increasing order of frequency resource index for frequency multiplexed PRACH cases.

[0101] - Third, the increasing order of time resource index for time-multiplexed PRACH cases within a PRACH slot.

[0102] - Fourth, the increasing order of the index for the PRACH slot

[0103] The association period starting from frame 0 for mapping SS / PBCH block indices to PRACH opportunities is the smallest integer in the set determined by the PRACH configuration period according to Table 8.1-1. If SS / PBCH block indices are mapped to a PRACH opportunity at least once within the association period, the UE may use the ssb-PositionsInBurst value of SIB1 or ServingCellConfigCommon. . After an integer number of cycles mapping from SS / PBCH block index to PRACH opportunity within the association period. If there is a PRACH opportunity or PRACH preamble set that is not mapped to an SS / PBCH block index, the SS / PBCH block index is not mapped to a PRACH opportunity or PRACH preamble set. The association pattern period includes one or more association periods, and the pattern between the PRACH occasion and the SS / PBCH block index is determined such that it repeats at most every 160 milliseconds.

[0104] After an integer number of association periods have elapsed, PRACH occasions not associated with an SS / PBCH block index are not used for PRACH transmission.

[0105] For PRACH transmissions triggered from higher layers, if ssb-ResourceList is provided, the PRACH mask index is indicated by ra-ssb-OccasionMaskIndex, which indicates the PRACH occasions for the PRACH transmission, where the PRACH occasions are associated with the selected SS / PBCH block index.

[0106] PRACH occasions are mapped consecutively for each SS / PBCH block index. The indexing of PRACH occasions indicated by the mask index value is reset for each consecutive PRACH occasion mapping period for each SS / PBCH block index. In the first available mapping period, the UE selects the PRACH occasion indicated by the PRACH mask index value for the indicated SS / PBCH block index for PRACH transmission.

[0107] For a given preamble index, the order of PRACH occasions is as follows:

[0108] - First, the increasing order of frequency resource indices for frequency-multiplexed PRACH occasions.

[0109] - Second, the increasing order of time resource indices for time-multiplexed PRACH occasions within a PRACH slot.

[0110] - Third, the increasing order of the index for the PRACH slot

[0111] For PRACH transmissions using preamble repetitions, the sets are temporally consecutive, use the same frequency resources, and are associated with the same one or more SS / PBCH block indices. It consists of valid PRACH occasions, and each SS / PBCH block index is associated with the same preamble index in all valid PRACH occasions within the set.

[0112] For PRACH transmissions with preamble repetition, the time period starting from frame 0 is The smallest integer number of associated pattern periods for which at least one set of valid PRACH occasions for each of the SS / PBCH block indices can be determined within the time period for all configured preamble repetition counts. The set(s) of valid PRACH occasions for each configured preamble repetition count are repeated in every time period.

[0113] Within a time period, For PRACH transmission with preamble repetition For a set(s) of valid PRACH occasions

[0114] - The first valid PRACH occasion in the first set is the first PRACH occasion.

[0115] - The first valid PRACH occasion in the subsequent sets (if any) is determined by the ordering of the valid PRACH occasions.

[0116] - First, in increasing order of frequency resource indices for frequency multiplexed PRACH occasions.

[0117] - Second, in increasing order of time resource indices for time-multiplexed PRACH occasions.

[0118] Here, for each frequency resource index for frequency multiplexed PRACH occasions,

[0119] - The first valid PRACH occasion in the first set is a valid PRACH occasion.

[0120] - The first valid PRACH occasion in the subsequent sets (if any) is

[0121] - After the first valid PRACH occasion of the previous set, there are TimeOffsetBetweenStartingRO valid PRACH occasions that are temporally consecutive, each PRACH occasion being associated with the same SS / PBCH block index, and each SS / PBCH block index being associated with the same preambles, if TimeOffsetBetweenStartingRO is provided.

[0122] - If TimeOffsetBetweenStartingRO is not provided, it is after the previous set of PRACH occasions.

[0123] Table 8.1-1: Mapping between PRACH configuration periods and SS / PBCH blocks and PRACH occasional connection periods

[0124]

[0125] The above-described settings / definitions / operations may be referenced to clarify the definitions / operations of the embodiments described below. For example, in the embodiments described below, RO may mean the PRACH occasion described above. For example, in the embodiments described below, an RO group including N ROs based on the number of repetitions (N) may be can be interpreted / replaced by a set of valid PRACH occasions. That is, one RO group can be interpreted / replaced by one set. For example, in the embodiment described below, the starting RO of an RO group can be interpreted / replaced by the first valid PRACH occasion of the set.

[0126] RA-RNTI (MSGB-RNTI)

[0127] The RA-RNTI and MSGB-RNTI currently applied to the FR1 / 2 area can be defined as follows.

[0128] 5.1.3 Random Access Preamble Transmission

[0129] The RA-RNTI associated with a PRACH opportunity during which a random access preamble is transmitted is calculated as follows:

[0130] RA-RNTI = 1 + s_id + 14 Х t_id + 14 Х 80 Х f_id + 14 Х 80 Х 8 Х ul_carrier_id

[0131] Here, s_id is the first OFDM symbol index of a PRACH opportunity (0 ≤ s_id < 14), t_id is the first slot index of a PRACH opportunity in the system frame (0 ≤ t_id < 80), the subcarrier spacing that determines t_id is based on the μ value specified in clause 5.3.2 of TS 38.211 [8], f_id is the index of a PRACH opportunity in the frequency domain (0 ≤ f_id < 8), and ul_carrier_id is the UL carrier used for random access preamble transmission (0 for NUL carrier, 1 for SUL carrier).

[0132] 5.1.3a MSGA Transmission

[0133] The MSGB-RNTI associated with a PRACH opportunity in which a random access preamble is transmitted is calculated as follows:

[0134] MSGB-RNTI = 1 + s_id + 14 Х t_id + 14 Х 80 Х f_id + 14 Х 80 Х 8 Х ul_carrier_id + 14 Х 80 Х 8 Х 2

[0135] where s_id is the first OFDM symbol index of a PRACH opportunity (0 ≤ s_id < 14), t_id is the first slot index of a PRACH opportunity in the system frame (0 ≤ t_id < 80), the subcarrier spacing that determines t_id is based on the μ value specified in clause 5.3.2 of TS 38.211 [8], f_id is the index of a PRACH opportunity in the frequency domain (0 ≤ f_id < 8), and ul_carrier_id is the UL carrier used for random access preamble transmission (0 for NUL carrier, 1 for SUL carrier). The RA-RNTI is computed as specified in clause 5.1.3.

[0136] RO group for PRACH repetition

[0137] In Rel-18 coverage enhancement, RO groups were introduced for PRACH repetition. When the base station sets / instructs the UE to specify a repetition number (N), N valid ROs are grouped in ascending order of time domain index among the valid ROs on the same frequency. This is illustrated in Figures 4 and 5. A more detailed explanation follows.

[0138] Figure 4 shows an example of an RO group for PRACH repetition.

[0139] The following settings are assumed for the determination of the RO group in Fig. 4.

[0140] # of repetition = 4, # of SSBs = 2, # of FDMed RO = 4, # of SSBs per RO = 1 / 2

[0141] '# of repetition' is the number of repetitions (e.g. =4) means.

[0142] '# of SSBs' is the number of SSBs based on the time period associated with the PRACH repeated transmission (e.g. ) represents. Specifically, the number of SSBs can be obtained as follows. The terminal obtains the number of SSBs ( from the value of the upper layer parameter ssb-PositionsInBurst. ) can be obtained. The upper layer parameter ssb-PositionsInBurst can be set / indicated based on a system information block (e.g., SIB1) or serving cell configuration information (e.g., ServingCellConfigCommon).

[0143] '# of FDMed RO' indicates the number of frequency-multiplexed ROs. The frequency-multiplexed ROs may refer to ROs within one time instance.

[0144] '# of SSBs per RO' indicates the number of SSBs per RO.

[0145] Referring to Figure 4, RO groups (1) associated with one of the two SSBs st RO Group~4 th RO group) is determined. ROs belonging to each RO group (1 st ~4 th ) are based on the same frequency resource index.

[0146] Figure 5 shows another example of a RO group for PRACH repetition.

[0147] Referring to Figure 5, the following settings are assumed for determining the RO group.

[0148] # of repetition = 4, # of SSBs = 3, # of FDMed RO = 4, # of SSBs per RO = 1

[0149] Referring to Figure 5, RO groups (1) associated with one of the three SSBs st RO Group~4 th RO group) is determined. ROs belonging to each RO group (1 st ~4 th ) are based on the same frequency resource index.

[0150] As described above, the RO groups are determined in ascending order of the frequency resource index of the first RO of each RO group, and when the frequency resource index is the same, the RO groups are determined in ascending order of the time resource index of the first RO of each RO group.

[0151] Among valid ROs associated with the same beam / SSB (e.g., same SS / PBCH block index), N ROs existing in the same frequency resource can be grouped into one RO group. The valid ROs associated with the same beam / SSB can refer to all ROs based on the four RO groups in FIGS. 4 and 5.

[0152] The contents discussed above 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 features of the methods proposed in this specification.

[0153] 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.

[0154] For example, uplink transmission through methods related to the PRACH transmission occasion configuration described later can be performed in an L-cell (a cell operating in a licensed band (L-band)) and / or a U-cell (a cell operating in an unlicensed band (U-band)) defined in an NR system or a U-Band system.

[0155] 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.

[0156] The NR frequency band is defined by two types of frequency ranges (FR1 and FR2). FR1 and FR2 can be configured as shown in Table 1 below. FR2 can also mean millimeter wave (mmW).

[0157]

[0158] As previously explained, Rel-18 coverage enhancement introduced RO groups for PRACH repetition. They were defined to be composed of only ROs located at the same frequency. If RO frequency hopping is additionally supported in addition to the PRACH repetition operation based on the RO groups, it can provide additional frequency diversity gains, thereby providing advantages in terms of coverage enhancement. Therefore, this specification proposes a method for performing RO frequency hopping between RO groups when PRACH (Msg. A) preamble repetition operation is defined.

[0159] Specifically, the present specification proposes 1) methods for selecting / determining multiple RO groups belonging to an RO group pair and 2) methods for performing RO frequency hopping between RO groups belonging to an RO group pair.

[0160] Specifically, the ROs used in multiple PRACH transmissions (or PRACH repetitions) mentioned in this specification are valid ROs (valid PRACH occasions). In this specification, 'PRACH transmission', 'RACH transmission', or 'preamble transmission' may be interpreted / replaced with 'MSG1 transmission'.

[0161] <RO group pairing determination>

[0162] It can be assumed that after the UE configures / determines the RO group for PRACH repetition, RO frequency hopping is enabled by the base station. The UE can be defined to select two RO groups for RO frequency hopping. Below, we will examine in detail the methods for selecting two RO groups for a specific RO group pair.

[0163] {Implicit determination for RO group pairing}

[0164] [Method 1]

[0165] 1. [1-1]: If there are two or more starting ROs for different RO groups that do not belong to a RO group pair at a specific time instance, the one with the lowest frequency position (i.e., frequency index (n)) is selected. RA ) can be determined as an RO group pair, with two RO groups belonging to two starting ROs in ascending order from the lowest starting RO. That is, hopping can be performed between two RO groups based on the corresponding RO group pair.

[0166] And, the above-described RO group pair determination operation can be repeatedly performed until there are less than 2 (i.e., 1) starting ROs of the RO group that do not belong to the RO group pair in the time instance.

[0167] If there are no more starting ROs of RO groups that do not belong to the RO group pair in the given time instance, the operation of [1-1] above can be performed on time instances that have starting ROs of RO groups that do not belong to the RO group pair while increasing the time instance in ascending order.

[0168] If there is a starting RO of an RO group that does not belong to the RO group pair in the given time instance, the following actions [1-2] can be performed.

[0169] 2. [1-2]: If there is only one starting RO of a specific RO group in the same time instance, the RO group pair is determined in ascending order of time instance (e.g., time resource index), and then the RO group pair can be determined in ascending order of frequency (e.g., frequency resource index).

[0170] The RO group with the first existing starting RO and the previously existing RO group can be determined as an RO group pair. Then, among the starting ROs of the RO groups belonging to the RO group pair, the operation of [1-1] or the operation of [1-2] can be performed again at the time instance corresponding to the larger time index value.

[0171] 3. The operation of [1-1] or the operation of [1-2] can be performed repeatedly until the time period X (K association pattern periods) ends.

[0172] An example of performing RO group pairing using the above [Method 1] is illustrated in Figs. 6 and 7.

[0173] Figure 6 shows an example of an RO group according to method 1 of the present specification.

[0174] In Fig. 6, the following settings are assumed.

[0175] # of repetition = 4, # of SSBs = 2, # of FDMed RO = 4, # of SSBs per RO = 1 / 2

[0176] Specifically, Fig. 6 shows an example of RO group pairing based on method 1. Referring to Fig. 6, RO group pairs (6A, 6B) are determined based on the operation of [1-1] above.

[0177] Figure 7 shows another example of an RO group according to method 1 of the present specification.

[0178] In Fig. 7, the following settings are assumed.

[0179] # of repetition = 4, # of SSBs = 3, # of FDMed RO = 4, # of SSBs per RO = 1

[0180] Specifically, Fig. 7 shows an example of RO group pairing based on method 1. Referring to Fig. 6, an RO group pair (7A) is determined based on the operation of [1-1], and an RO group pair (7B) is determined based on the operation of [1-2].

[0181] [Method 2]

[0182] 1. [2-1]: The RO group with the lowest frequency position among the RO groups that do not belong to the RO group pair at a specific time instance (i.e., frequency index (n) RA) can be determined as an RO group pair between an RO group having the lowest starting RO (e.g., RO group 1) and an RO group having the next starting RO (e.g., RO group 2).

[0183] The RO group having the starting RO existing in the next order above can be determined in ascending order of the time instance (e.g., time resource index) of the starting RO and / or in ascending order of the frequency (e.g., frequency resource index) of the starting RO.

[0184] For example, based on the ascending order of the time instance (e.g., time resource index) of the starting RO, RO group 2 may be determined as the RO group with the lowest time instance of the starting RO, following the starting RO of RO group 1.

[0185] Hopping can be performed between two RO groups (e.g., RO group 1, RO group 2) based on a RO group pair.

[0186] [2-1-A] It may be assumed that a second RO of the initially selected RO group (e.g., RO group 1) exists in a subsequent time instance. For example, the starting RO of RO group 1 and the starting ROs of other RO groups may exist in the same time instance. In this case, an RO group pair may be determined based on the frequency of a specific time instance (e.g., the time instance of the starting RO of RO group 1). The RO group (e.g., RO group 1) and the RO group with the starting RO that exists first in ascending frequency order (e.g., RO group 2) may be determined as an RO group pair.

[0187] Specifically, if there is no RO group determined in ascending order of the time instance of the starting RO (e.g., if the starting ROs of other RO groups exist in the same time instance as the starting RO of RO group 1), RO group 2 can be determined as follows: Based on the ascending order of the frequency (e.g., frequency resource index) of the starting RO, RO group 2 can be determined as the RO group whose starting RO has the lowest frequency (e.g., frequency resource index) after the starting RO of RO group 1.

[0188] 2. [2-2] If there are any starting ROs remaining in the RO group that are not bound to the RO group pair at a specific time instance, the operation of [2-1] can be repeated for the RO groups that are not bound to the RO group pair.

[0189] 3. [2-3] If there are no more RO groups that are not grouped into RO group pairs in a specific time instance, the operations of [2-1] and [2-2] above can be performed in the next time instance. The operations of [2-3] can be repeatedly performed in ascending order of time instances.

[0190] 4. The operation of [2-1] or [2-2] or [2-3] can be performed repeatedly until the time period X (K association pattern periods) ends.

[0191] An example of performing RO group pairing using the above [Method 2] is illustrated in Figs. 8 and 9.

[0192] Figure 8 shows an example of an RO group according to method 2 of the present specification.

[0193] In Fig. 8, the following settings are assumed.

[0194] # of repetition = 4, # of SSBs = 2, # of FDMed RO = 4, # of SSBs per RO = 1 / 2

[0195] Specifically, Fig. 8 shows an example of RO group pairing based on method 2. Referring to Fig. 8, RO group pairs (8A, 8B) are determined based on the operation of [2-1-A].

[0196] Figure 9 shows another example of an RO group according to method 2 of the present specification.

[0197] In Fig. 9, the following settings are assumed.

[0198] # of repetition = 4, # of SSBs = 3, # of FDMed RO = 4, # of SSBs per RO = 1

[0199] Specifically, Fig. 9 shows another example of RO group pairing based on method 2. Referring to Fig. 9, an RO group pair (9A) is determined based on the operation of [2-1]. That is, RO group 1 is an RO group based on the lowest frequency resource index among the two RO groups belonging to 9A. RO group 2 is a starting RO (1) of RO group 1 among the two RO groups belonging to 9A. st ) Next, the starting RO(1) that exists first in ascending order of time instance st ) is a RO group.

[0200] Afterwards, the RO group pair (9B) is determined based on the operation of [2-1-A]. That is, RO group 1 is the RO group based on the lowest frequency resource index among the two RO groups belonging to 9B. RO group 2 is the starting RO (1) of RO group 1 among the two RO groups belonging to 9B. st ) Next, starting RO(1) exists first in ascending frequency order st ) is a RO group.

[0201] In the examples according to the parameters used in Figs. 6 and 8, [Method 1] and [Method 2] have the same results. The RO group pairs (6A, 6B) in Fig. 6 and the RO group pairs (8A, 8B) in Fig. 8 are identical.

[0202] In the examples according to the parameters used in Figs. 7 and 9, [Method 1] and [Method 2] produce different results. That is, the RO group pairs (7A, 7B) of Fig. 7 and the RO group pairs (9A, 9B) of Fig. 9 are different.

[0203] Specifically, when an RO group pair is determined based on [Method 2], the frequency interval between the RO groups of each RO group pair is the same as two ROs (based on the starting RB of each RO). On the other hand, when an RO group pair is determined based on [Method 1], the frequency intervals associated with each RO group pair are different. The RO groups of one RO group pair (7B) have a frequency interval of one RO (based on the starting RB of each RO) (e.g., frequency resource indexes 1, 2). The RO groups of another RO group pair (7A) have a frequency interval of three ROs (based on the starting RB of each RO) (e.g., frequency resource indexes 0, 3).

[0204] When a terminal attempts to perform repeated PRACH transmissions, and the MAC layer randomly selects a starting RO, it may be desirable to have the same interval for RO frequency hopping. In this case, [Method 2] can be applied.

[0205] The base station can configure / instruct the terminal to use the RO group pair method based on the SIB (System Information Block). For example, the base station can select either Method 1 or Method 2 and configure / instruct the terminal to use the method according to the PRACH configuration (or repetition number) that supports PRACH repetition.

[0206] { Explicit configuration for RO group pairing}

[0207] [Method 3]

[0208] 1. It can be assumed that M starting ROs associated with the same SSB index (SS / PBCH block index) exist in a specific time instance, frequency-division multiplexed (FDMed). The base station can configure / instruct the UE to use one of the RO group pair combinations defined below as a common value via SIB. Alternatively, RO group pair combinations based on repetition number or PRACH configuration can be predefined.

[0209] 2. Alternatively, the frequency interval (e.g., the difference in frequency indices) between the RO groups forming a RO group pair can be defined in advance.

[0210] For example, the difference between the above frequency indices can be floor(M / 2) or ceil(M / 2). Specifically, the difference between the frequency indices of RO group 1 and RO group 2 can be floor(M / 2) or ceil(M / 2).

[0211] For example, the frequency interval can be defined / expressed as the interval between the starting RBs of the starting ROs of the RO groups. That is, when the number of RBs occupied by one RO is Q, the frequency interval can be expressed as floor(M / 2)*Q RB or ceil(M / 2)*Q RB.

[0212] 3. For example, the base station can set / instruct the terminal via SIB the frequency index difference (i.e., delta) between the RO groups forming the RO group pair as a common value. For example, the base station can set / instruct the terminal the values ​​for the frequency index difference according to the repetition number or PRACH configuration. For example, a delta value having a common value (or an independent delta value for each repetition number or PRACH configuration) can be defined in advance (e.g., delta = 1).

[0213] 4. Below, examples of RO group pair combinations according to M values ​​are described.

[0214] A. Here, the value in {} represents the (relative) frequency domain index value. Delta represents the frequency index difference between RO groups of each RO group pair based on the M ROs associated with the same SSB index. If delta is absent, the frequency index difference may vary for each RO group pair.

[0215] B. M=2

[0216] RO group pair combination #1: {0, 1} (delta = 1)

[0217] C. M=4

[0218] RO group pair combination #1: {0, 1}, {2, 3} (delta = 1)

[0219] RO group pair combination #2: {0, 2}, {1, 3} (delta = 2)

[0220] RO group pair combination #3: {0, 3}, {1, 2}

[0221] D. M=6

[0222] RO group pair combination #1: {0, 1}, {2, 3}, {4, 5} (delta = 1)

[0223] RO group pair combination #2: {0, 3}, {1, 4}, {2, 5} (delta = 3)

[0224] RO group pair combination #3: {0, 2}, {1, 4}, {3, 5}

[0225] RO group pair combination #4: {0, 4}, {1, 5}, {2, 3}

[0226] RO group pair combination #5: {0, 5}, {1, 4}, {2, 3}

[0227] E. M=8

[0228] RO group pair combination #1: {0, 1}, {2, 3}, {4, 5}, {6, 7} (delta = 1)

[0229] RO group pair combination #2: {0, 2}, {1, 3}, {4, 6}, {5, 7} (delta = 2)

[0230] RO group pair combination #3: {0, 4}, {1, 5}, {2, 6}, {3, 7} (delta = 4)

[0231] RO group pair combination #4: {0, 3}, {1, 2}, {4, 7}, {5, 6}

[0232] RO group pair combination #5: {0, 6}, {1, 7}, {2, 4}, {3, 5}

[0233] RO group pair combination #6: {0, 7}, {1, 6}, {2, 5}, {3, 4}

[0234] The combination of RO group pairs according to the above-described M values ​​is an example. The technical ideas according to the embodiments of the present specification are not intended to be limited to examples of combinations of RO group pairs according to each M value.

[0235] 5. If M is an odd number, the RO group pairing operation can only be performed between M-1 RO groups (from the lowest (or highest) frequency).

[0236] An example of performing RO group pairing using the above [Method 3] is illustrated in Fig. 10.

[0237] Figure 10 shows an example of an RO group according to method 3 of the present specification.

[0238] In Fig. 10, the following settings are assumed.

[0239] # of repetition = 4, # of SSBs = 3, # of FDMed RO = 4, # of SSBs per RO = 1

[0240] Referring to Fig. 10, in the first time instance, there are two starting ROs. That is, M=2, and the relative frequency domain index values ​​are 0 for the lowest frequency RO and 1 for the highest frequency RO. These two RO groups can be determined as an RO group pair (10A). In other time instances, since there is only one starting RO in each instance (the relative frequency domain index values ​​are 0 in each instance), these RO groups are not determined as an RO group pair. In other words, the RO groups belonging to 10B are not used for RO group pairing.

[0241] [Method 3] can be configured to be used primarily in situations where there are many starting ROs in a specific time instance (e.g., # of repetitions = 4, # of SSBs = 2, # of FDMed RO = 4, # of SSBs per RO = 1 / 4). This is represented graphically as in Fig. 11.

[0242] Figure 11 shows another example of an RO group according to method 3 of the present specification.

[0243] In Fig. 11, the following settings are assumed.

[0244] # of repetition = 4, # of SSBs = 2, # of FDMed RO = 4, # of SSBs per RO = 1 / 4

[0245] Referring to Fig. 11, since M is 4, two RO group pairs (11A, 11B) can be determined. The RO group pairs (11A, 11B) can be based on the RO group pair combination #2: {0, 2}, {1, 3} (delta = 2) among the examples described above.

[0246] The terminal / base station operations that can be commonly applied to the above-described methods are listed below.

[0247] 1. The base station can set / instruct the terminal via SIB whether to support RO frequency hopping operation.

[0248] For example, whether the RO frequency hopping operation is supported can be set / indicated for each PRACH configuration in which the PRACH repetition is set.

[0249] For example, whether the RO frequency hopping operation is supported can be set / indicated for each different repetition number in the PRACH configuration in which the PRACH repetition is set.

[0250] 2. RO groups that do not belong to a specific RO group pair do not support RO frequency hopping.

[0251] 3. A specific RO group cannot be included in more than two RO group pairs.

[0252] 4. RO group pairing can be defined within RO groups belonging to time period X (K association pattern periods).

[0253] 5. For an RO group that is grouped using N valid ROs, but cannot use all N due to collisions with other signals / channels, the following actions can be applied.

[0254] Alt 1) The RO group is excluded from RO group pairing.

[0255] Alt 2) Include the relevant RO group in the RO group pairing, but set it to drop the RO that cannot actually transmit without delaying (postponing).

[0256] 6. The base station may also configure, via SIB, one of the above methods to be applied equally across all PRACH configurations that support repetition. For example, the base station may instruct, via SIB, that one of the above methods be used independently for each PRACH configuration that supports repetition.

[0257] < RO frequency hopping pattern >

[0258] After RO group pairing is completed using the aforementioned methods for determining RO group pairing (Methods 1 through 3), it is necessary to define how the terminal should hop between ROs. Below, we specifically describe the RO frequency hopping pattern applicable between two RO groups within an RO group pair.

[0259] [Method A]

[0260] A. Within an RO group consisting of N ROs according to the repetition number N, the relative time index of each RO is referred to as index 0, 1, 2, 쪋, N-1. In an even indexed (0, 2, 4, 쪋, N-2) RO, the RO of the next RO group can be selected as follows. In an even indexed (0, 2, 4, 쪋, N-2) RO, the RO of the RO group with a relatively smaller time index of the starting RO (if the time index is the same, the frequency index is relatively smaller) can be selected.

[0261] In an odd indexed (1, 3, 5, 쪋, N-1) RO, the RO of the next RO group can be selected as follows: In an odd indexed (1, 3, 5, 쪋, N-1) RO, an RO of another RO group that has not been previously selected within the corresponding RO group pair can be selected.

[0262] For example, it can be assumed that N is 4 and each RO group contains 4 ROs (RO 0 to RO 3). An even indexed RO (e.g., RO 0) of RO group 1 (or RO group 2) can be selected followed by an odd indexed RO (e.g., RO 1) of RO group 2 (or RO group 1).

[0263] [Example 1] RO 0 of RO group 1 -> RO 1 of RO group 2 -> RO 2 of RO group 1 -> RO 3 of RO group 2

[0264] [Example 2] RO 0 of RO group 2 -> RO 1 of RO group 1 -> RO 2 of RO group 2 -> RO 3 of RO group 1

[0265] RO frequency hopping is performed based on the selection of the RO described above.

[0266] B. Afterwards, RO frequency hopping is performed between unselected ROs.

[0267] [Method B]

[0268] A. Among the two RO groups belonging to an RO group pair (e.g., RO group index K & L), the starting RO corresponding to the RO group with a relatively smaller time index (if the time indices are the same, the starting RO with a relatively smaller frequency index) is selected. The RO corresponding to the next index in time can be selected by hopping to another RO group within the RO group pair that was not previously selected.

[0269] B. RO frequency hopping can be performed based on the ROs that were not selected thereafter.

[0270] Additionally, an example of a RO frequency hopping pattern using the above [Method A] and / or [Method B] is illustrated in FIG. 12.

[0271] FIG. 12 illustrates a frequency hopping pattern according to one embodiment of the present specification.

[0272] In Fig. 12, the following settings are assumed.

[0273] # of repetition = 4, # of SSBs = 3, # of FDMed RO = 4, # of SSBs per RO = 1

[0274] Specifically, Fig. 12 is an example assuming a situation in which RO group pairing is performed using [Method 2] above. That is, the RO group pairs are identical to 9A and 9B of Fig. 9. The starting ROs of the RO groups belonging to the first RO group pair corresponding to 9A of Fig. 9 are 12A and 12B. The starting ROs of the RO groups belonging to the second RO group pair corresponding to 9B of Fig. 9 are 12C and 12D.

[0275] As an example, the RO frequency hopping pattern starting from 12A is as follows:

[0276] The first RO in RO group 1 (e.g., RO 0) -> the second RO in RO group 2 (e.g., RO 1) -> the third RO in RO group 1 (e.g., RO 2) -> the fourth RO in RO group 2 (e.g., RO 3)

[0277] For example, the RO frequency hopping pattern starting from 12B is as follows:

[0278] The first RO of RO group 2 (e.g., RO 0) -> the second RO of RO group 1 (e.g., RO 1) -> the third RO of RO group 2 (e.g., RO 2) -> the fourth RO of RO group 1 (e.g., RO 3)

[0279] Additionally, another example of a RO frequency hopping pattern using the above [Method A] and / or [Method B] is illustrated in FIG. 13.

[0280] FIG. 13 illustrates a frequency hopping pattern according to another embodiment of the present specification.

[0281] In Fig. 13, the following settings are assumed.

[0282] # of repetition = 4, # of SSBs = 2, # of FDMed RO = 4, # of SSBs per RO = 1 / 4

[0283] Specifically, Fig. 13 is an example that assumes a situation in which RO group pairing is performed using [Method 3] above. In the case of Fig. 13, RO group pair combination #1: {0, 1}, {2, 3} (delta = 1) is assumed. That is, the starting ROs of the RO groups (0, 1) belonging to the first RO group pair are 13A and 13B. The starting ROs of the RO groups (2, 3) belonging to the second RO group pair are 13C and 13D.

[0284] As an example, the RO frequency hopping pattern starting from 13A is as follows:

[0285] The first RO in RO group 0 (e.g., RO 0) -> the second RO in RO group 1 (e.g., RO 1) -> the third RO in RO group 0 (e.g., RO 2) -> the fourth RO in RO group 1 (e.g., RO 3)

[0286] For example, the RO frequency hopping pattern starting from 13B is as follows:

[0287] The first RO in RO group 1 (e.g., RO 0) -> the second RO in RO group 0 (e.g., RO 1) -> the third RO in RO group 1 (e.g., RO 2) -> the fourth RO in RO group 0 (e.g., RO 3)

[0288] [Method C]

[0289] A. Within an RO group consisting of N ROs according to the repetition number N, the relative time index of each RO is referred to as index 0, 1, 2, 쪋, N-1. After the first X ROs are selected, Y ROs can be selected.

[0290] The above X ROs may be ROs of an RO group in which the time index of the starting RO is relatively small (if the time index is the same, the frequency index is relatively small).

[0291] The above Y ROs may be ROs of other RO groups that have not been previously selected within the RO group pair.

[0292] The above operation can be repeated until the Repetition number is filled.

[0293] The X and Y values ​​for the above-described RO frequency hopping can be set / indicated / defined as follows.

[0294] For example, the base station can set / indicate X and Y for each PRACH configuration with repetition set via SIB.

[0295] For example, a base station can set / indicate X and Y for each Repetition number within PRACH configurations with repetition set via SIB.

[0296] For example, X and Y for the above-described RO frequency hopping can be defined in advance.

[0297] For example, X and Y for the above-described RO frequency hopping can be implicitly determined by the terminal.

[0298] 1. For example, if X=1, Y=1, it is the same as [Method A] or [Method B].

[0299] 2. For example, X and Y can be independently set / indicated. For example, only X can be indicated and Y can be used as a replacement for X (or only X can be introduced and used without Y). That is, RO frequency hopping can be performed using ROs of different RO groups belonging to the RO group pair for every X transmissions.

[0300] 3. Specific examples in which the values ​​for X and Y are defined in advance are as follows. For example, the X value may be set to floor(N / d) and the Y value may be set to ceil(N / d). For example, the X value may be set to ceil(N / d) and the Y value may be set to floor(N / d) (e.g., if d=2, then N=X+Y, and if d=4, then N=2X+2Y).

[0301] B. The base station can set / indicate X and Y based on the minimum repetition number set in the corresponding PRACH configuration. When applying a repetition number greater than that, the terminal can be configured to sequentially repeat the application of X and Y.

[0302] C. The base station can set / indicate X and Y values ​​for a relatively small repetition number within the corresponding PRACH configuration. When applying a larger repetition number, the terminal can be configured to aggregate the previously set / indicated values ​​until the repetition number is satisfied.

[0303] D. The base station can set / indicate X and Y values ​​for the minimum repetition number set in the PRACH configuration. The terminal can be set to apply scaling to the X and Y values ​​by the amount that the repetition number selected by the terminal is scaled compared to the minimum repetition number. That is, it can be assumed that the minimum repetition number is 4 and the repetition number selected by the terminal is 8. In this case, 2X and 2Y with scaling applied by (8 / 4=)2 can be used.

[0304] As described above, multiple RO groups are initially configured, and based on this, two RO groups can be paired. Next, an operation to determine an RO frequency hopping pattern between the RO groups within the RO group pair can be performed. The above-described operations (pairing, pattern determination) can be performed explicitly or implicitly.

[0305] Afterwards, when repeated PRACH transmissions are required from the actual terminal, a starting RO can be randomly selected at the MAC layer. Repeated transmissions can then be performed according to the previously configured RO frequency hopping pattern.

[0306] At this time, the RA-RNTI value determined by the terminal and the base station can be defined to be calculated based on the last valid RO among multiple ROs to which the frequency hopping pattern is applied (similar to the existing PRACH repetition operation). That is, the RA-RNTI value can be calculated regardless of whether actual transmission (i.e., whether a drop is made) is performed based on the last valid RO.

[0307] Additionally, the RAR window starting point determined by the terminal and base station can be defined as starting after the last OFDM symbol of the last valid RO within multiple ROs to which the frequency hopping pattern is applied (similar to the existing PRACH repetition operation). Similarly, the RAR window starting point can also be defined regardless of whether actual transmission (i.e., whether a drop is made) is performed based on the last valid RO.

[0308] < RO group pairing determination and RO frequency hopping pattern for multiple RO groups >

[0309] The above-described embodiments considered a case where a specific RO group pair includes two RO groups. However, it can be assumed that even if a base station is configured with four FDMed ROs, ROs in a specific frequency range are always determined to be invalid ROs. In this case, only a maximum of three starting ROs remain at a given time instance. If RO group pairing is performed using only the RO groups corresponding to the two starting ROs, at most one RO group will remain incapable of frequency hopping among the RACH resources. Therefore, there is a disadvantage in that too many RO groups do not support frequency hopping. A method to address this issue is described in detail below.

[0310] Specifically, a method may be considered for determining that a certain number of RO groups, P, greater than 2 (a positive integer where P>2), are included in a specific RO group pair. Simply, implicit methods among the methods for determining the RO group pairing may be extended and applied.

[0311] For example, according to [Method 1] and / or [Method 2], the first two RO groups are determined as RO group pairs according to the progression order. According to the present embodiment, the above-described operation can be performed as follows. The first P RO groups can be determined as RO group pairs according to the progression order. P can be 3, and this can be represented graphically as in Fig. 14.

[0312] FIG. 14 illustrates pairing of P RO groups according to one embodiment of the present specification.

[0313] In Fig. 14, the following settings are assumed.

[0314] # of repetition = 4, # of SSBs = 2, # of FDMed RO = 4, # of SSBs per RO = 1 / 4

[0315] Referring to Fig. 14, three RO groups can be determined as RO group pairs (14A). 14B represents invalid ROs.

[0316] Additionally, after the RO group pairing based on P RO groups is completed, an RO frequency hopping pattern may be required between the P RO groups. That is, the relative time indices of the ROs within an RO group consisting of N ROs according to the repetition number N can be defined as index 0, 1, 2, 쪋, N-1, and the relative frequency indices of the ROs can be defined as index 0, 1, 2, 쪋, P-1.

[0317] Based on the definition, the RO frequency hopping pattern based on the RO group pair consisting of P RO groups is described in detail below.

[0318] When RO frequency hopping is enabled, the terminal selects a starting RO having the smallest initial relative time index and / or frequency index. Thereafter, the terminal selects an RO corresponding to the relative time index by increasing it by 1 and changing the relative frequency index by k. As described above, ROs for multiple PRACH transmission can be configured to be selected. Thereafter, the next starting RO can be determined in ascending order of frequency first / time second. That is, the next starting RO can be determined by applying the frequency ascending order first and the time ascending order second.

[0319] The above operation can be set to be repeated from the corresponding starting RO. When the changed relative frequency index is less than 0 or greater than P-1, a modular operation using the P value can be set to select a value between 0 and P-1.

[0320] The above method is expressed in a diagram as in Figure 15.

[0321] Figure 15 illustrates an example of a frequency hopping pattern based on P RO groups according to one embodiment of the present disclosure. Specifically, Figure 15 illustrates an example of applying RO frequency hopping when RO group pairs are determined as in Figure 14. In this case, N=4, P=3, and k=1 are applied.

[0322] As an example, the RO frequency hopping pattern starting from 15A is as follows:

[0323] The first RO of RO group 0 (e.g., RO 0) -> the second RO of RO group 1 (e.g., RO 1) -> the third RO of RO group 2 (e.g., RO 2) -> the fourth RO of RO group 0 (e.g., RO 3)

[0324] Additionally, another example of the above method can be represented in a drawing as shown in Fig. 16.

[0325] FIG. 16 illustrates another example of a frequency hopping pattern based on P RO groups according to one embodiment of the present specification.

[0326] Specifically, Fig. 16 is an example of applying RO frequency hopping when the RO group pair is determined as in Fig. 14. At this time, N=4, P=3, and k=-1 were applied.

[0327] As an example, the RO frequency hopping pattern starting from 16A is as follows:

[0328] The first RO in RO group 0 (e.g., RO 0) -> the second RO in RO group 2 (e.g., RO 1) -> the third RO in RO group 1 (e.g., RO 2) -> the fourth RO in RO group 0 (e.g., RO 3)

[0329] Specifically, the relative frequency index of the first RO in RO group 0 is 0, and adding k=-1 gives -1. The modular value (-1mod3) based on P for -1 is 2, so the next RO becomes the second RO (RO1) in RO group 2.

[0330] Additionally, depending on the number of starting ROs in a specific time instance (or whether the number of starting ROs in a specific time instance is even or odd), the number of RO groups included in the RO group pairing can be set differently.

[0331] For example, if there are 2, 4, 6, or 8 starting ROs (i.e., an even number) at a particular time instance, the number of RO groups for RO group pairing can be defined as 2.

[0332] For example, if there are 5 or 7 starting ROs (i.e., an odd number excluding 1 and 3) at a given time instance, RO group pairing can be performed as follows: Every two RO groups based on the two starting ROs with the lowest frequency are determined as an RO group pair. Finally, three RO groups based on the remaining three starting ROs can be determined as an RO group pair.

[0333] For example, if there are three starting ROs in a specific time instance, three RO groups based on the three starting ROs can be determined as RO group pairs.

[0334] Afterwards, different RO frequency hopping patterns can be applied to RO group pairs grouped in pairs of two and RO group pairs grouped in pairs of three. The method for applying the RO frequency hopping pattern can be configured to suit each case (i.e., the number of RO groups in the RO group pair).

[0335] <RO group determination method considering RO frequency hopping>

[0336] When determining an RO group, a form that considers the RO frequency hopping operation can be considered. If the PRACH repetition factor is set to N and it can be assumed that there are M FDMed ROs in a specific time instance, multiple ROs can be sequentially selected from among valid ROs associated with the same SSB within a specific time period X (e.g., K SSB-to-RO association pattern periods). Based on the above selection, a method of forming an RO group that considers frequency hopping can be considered.

[0337] Specifically, a valid RO with the smallest time / frequency index within a specific time period X can be set as the starting RO. Floor(N / 2) (or ceil(N / 2)) ROs having the same frequency index as the starting RO (including the starting RO) can be selected.

[0338] Among the valid ROs existing in the time instance after the previously selected RO, ceil(N / 2) (or floor(N / 2)) other ROs having a frequency index that is floor(M / 2) away from the frequency index of the previously selected starting RO can be selected. In this case, instead of floor(M / 2), ceil(M / 2), the number of RBs occupied by one RO, or the interval between L ROs in frequency can be applied.

[0339] As above, i) first selected floor(N / 2) (or ceil(N / 2)) ROs and ii) subsequently selected ceil(N / 2) (or floor(N / 2)) ROs can be set to form (one) RO group to be used for PRACH repetition.

[0340] For example, the L value can be predefined for each PRACH configuration (or repetition number). For example, the L value can be set / instructed to the terminal by the base station.

[0341] The action can be set to repeat until the time period X ends.

[0342] In addition, the proposed method can be set / applied to other UL signals / channels such as 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. A rule can be defined so that the base station notifies the terminal of whether the methods are applied (or information about the rules of the 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.

[0343] 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.

[0344] In terms of implementation, the operations of the base station / terminal according to the embodiments described above (e.g., operations based on at least one of the methods for determining RO group pairing, the methods for RO frequency hopping patterns, the methods for determining RO group pairing for multiple RO groups, and / or the methods for determining RO groups considering RO frequency hopping) can be processed by the device of FIG. 19 described below (e.g., the processor (110, 210) of FIG. 19).

[0345] In addition, the operations of the base station / terminal according to the above-described embodiment (e.g., operations based on at least one of the methods for determining RO group pairing, the methods for RO frequency hopping pattern, the methods for determining RO group pairing for multiple RO groups, and / or the methods for determining RO group considering RO frequency hopping) may be stored in a memory (e.g., 140, 240 of FIG. 19) in the form of a command / program (e.g., instruction, executable code) for driving at least one processor (e.g., 110, 210 of FIG. 19).

[0346] The embodiments described below are specifically described with reference to FIGS. 17 and 18 in terms of the operation of the terminal and base station. The methods described below are distinguished for convenience of explanation, and it is understood that some components of one method may be substituted for some components of another method or may be applied in combination with each other.

[0347] FIG. 17 is a flowchart illustrating a method performed by a terminal according to one embodiment of the present specification.

[0348] Referring to FIG. 17, a method performed by a terminal according to one embodiment of the present specification includes a RACH configuration reception step (S1710) and a PRACH transmission step (S1720).

[0349] In step S1710, the terminal receives a Random Access Channel (RACH) configuration from the base station. For example, the RACH configuration may include information based on the configuration / operation related to the above-described random access preamble.

[0350] In step S1720, the terminal transmits a Physical Random Access Channel (PRACH) to the base station based on the sets. For example, the transmission of the PRACH may be performed based on the settings / operations related to the random access preamble described above.

[0351] Specifically, each of the above sets has a number of repetitions (e.g., ) may include PRACH occasions based on the set. For example, each set may include Valid PRACH opportunities for dogs ( The valid PRACH occasions may include consecutive PRACH occasions in time, use the same frequency resource(s), and are associated with the same Synchronization Signal / Physical Broadcast CHannel Block index (SS / PBCH Block index)(s).

[0352] The transmission of the above PRACH can be interpreted / replaced with the transmission of the above MSG1. That is, the repetition of MSG1 can be interpreted / replaced with the repetition of PRACH. If the random access procedure is a Type-2 random access procedure, MSG1 can be interpreted / replaced with MSGA.

[0353] Frequency hopping may be supported for PRACH repeated transmission based on at least one of the above-described embodiments (e.g., at least one of the methods for determining RO group pairing (Methods 1 to 3), the methods for RO frequency hopping pattern (Methods A to C), the methods for determining RO group pairing for multiple RO groups and / or the methods for determining RO groups considering RO frequency hopping). That is, the PRACH may be transmitted based on frequency hopping. This will be described in detail below. In the description below, 'PRACH occasion' may mean RO in the above-described embodiments, 'set' may mean 'RO group' in the above-described embodiments, and 'first PRACH occasion' of each set may mean 'starting RO' of each RO group in the above-described embodiments.

[0354] In one embodiment, the sets may include a first set and a second set related to frequency hopping. The first set and the second set may be determined based on an order of a time resource index and / or a frequency resource index of a first PRACH occasion within each set among the sets within a time period. The present embodiment may be based on one of Methods 1 to 3 for determining RO group pairing. For example, the time period may mean time period X (K association pattern periods) in the above-described embodiments. The time period X may mean a time period mentioned in the configuration / operation related to the above-described random access preamble. For example, the first set may mean one of two RO groups (e.g., RO group 1) belonging to the above-described RO group pair, and the second set may mean the other one of the two RO groups (e.g., RO group 2).

[0355] For example, the second set may be determined in ascending order of the time resource index from the first set having the lowest frequency resource index among the sets within the time interval. This embodiment may be based on [2-1] of Method 2. Referring to FIG. 9, the first set and the second set may be based on 9A.

[0356] For example, based on the absence of a set based on the time resource index greater than the time resource index based on the first set among the sets: the second set may be determined in ascending order of the frequency resource index from the first set. The present embodiment may be based on [2-1-A] of Method 2. Referring to FIG. 9, the first set and the second set may be based on 9B. In this case, the absence of a set based on the time resource index greater than the time resource index based on the first set may include a case where the sets are based on the same time resource index (e.g., see 8A, 8B of FIG. 8).

[0357] In one embodiment, the frequency hopping may be performed based on i) a first PRACH occasion selected from the first set or the second set, and ii) a second PRACH occasion selected from the second set or the first set. The present embodiment may be based on one of Methods A to C for an RO frequency hopping pattern. The RO frequency hopping pattern is described below with reference to FIG. 12.

[0358] Referring to 12A of FIG. 12, the RO frequency hopping pattern starting from 12A as described above is as follows.

[0359] The first RO in RO group 1 (e.g., RO 0) -> the second RO in RO group 2 (e.g., RO 1) -> the third RO in RO group 1 (e.g., RO 2) -> the fourth RO in RO group 2 (e.g., RO 3)

[0360] For example, the first PRACH occasion may mean the first PRACH occasion (e.g., RO 0) or the third PRACH occasion (e.g., RO 2) of the first set, and the second PRACH occasion may mean the second PRACH occasion (e.g., RO 1) or the fourth PRACH occasion (e.g., RO 3) of the second set.

[0361] Referring to 12B of FIG. 12, the RO frequency hopping pattern starting from 12B as described above is as follows.

[0362] The first RO of RO group 2 (e.g., RO 0) -> the second RO of RO group 1 (e.g., RO 1) -> the third RO of RO group 2 (e.g., RO 2) -> the fourth RO of RO group 1 (e.g., RO 3)

[0363] For example, the first PRACH occasion may mean the first PRACH occasion (e.g., RO 0) or the third PRACH occasion (e.g., RO 2) of the second set, and the second PRACH occasion may mean the second PRACH occasion (e.g., RO 1) or the fourth PRACH occasion (e.g., RO 3) of the first set.

[0364] As described above, the first PRACH occasion and the second PRACH occasion are based on different sets. The second PRACH occasion may be located after the first PRACH occasion in the time domain. In other words, the index associated with the second PRACH occasion (e.g., one of indices 0 to N-1 based on the number of repetitions N) may be the next index of the index associated with the first PRACH. For example, when the number of repetitions is 4, frequency hopping may be performed as follows.

[0365] 1st PRACH occasion (RO 0) -> 2nd PRACH occasion (RO 1) -> 1st PRACH occasion (RO 2) -> 2nd PRACH occasion (RO 3)

[0366] In one embodiment, the sets may include i) the first set and the second set and / or ii) a third set. The present embodiment may be based on methods 1 to 3 and / or a method for determining an RO group considering RO frequency hopping. For example, the third set may include the PRACH occasions related to the frequency hopping. In other words, the third set may refer to an RO group configured considering RO frequency hopping. This will be described in detail below.

[0367] The frequency hopping associated with the third set may be performed based on indices associated with the repetition count (e.g., 0 to N-1 when the repetition count is N). For example, when the repetition count is 4, the indices of the four PRACH occasions included in the third set may be 0 to 3. The following description will be given with reference to the time / frequency domain of FIG. 15.

[0368] The third set includes four PRACH occasions. The indices 0 to 3 may correspond to time resource indices 0 to 3. Specifically, the frequency resource index of a PRACH occasion based on index 0 may be 0, and the frequency resource index of a PRACH occasion based on index 1 may be 1. The frequency resource index of a PRACH occasion based on index 2 may be 0, and the frequency resource index of a PRACH occasion based on index 3 may be 1. In this example, the frequency interval is assumed to be an interval corresponding to one PRACH occasion (i.e., the frequency resource index difference is 1).

[0369] In the third set, a frequency resource index of a PRACH occasion based on one of the indices (e.g., 0) may be different from a frequency resource index of a PRACH occasion based on a next of the indices (e.g., 1). Frequency hopping may be performed based on PRACH occasions within one set (the third set) without changing the set. In this case, a frequency interval between PRACH occasions based on different indices may be based on at least one of Methods 1 to 3. For example, the frequency interval may be defined in advance. For example, the frequency interval may be determined based on the number (M) of PRACH occasions that are frequency division multiplexed in the same time instance (e.g., floor(M / 2) or ceil(M / 2)).

[0370] In one embodiment, the method may further include a SIB receiving step. Specifically, the terminal receives a System Information Block (SIB) from the base station. The SIB may include settings related to frequency hopping. The SIB receiving step may be performed prior to S1710.

[0371] The above-described configuration related to frequency hopping may include information based on the above-described embodiments. For example, the above-described configuration related to frequency hopping may include i) information indicating whether the frequency hopping is enabled, ii) information related to determining the first set and the second set, and / or iii) information related to determining a PRACH occasion for the frequency hopping.

[0372] The operations based on the above-described S1710 to S1720 and SIB reception steps can be implemented by the device of FIG. 19. For example, the terminal (200) can control one or more transceivers (230) and / or one or more memories (240) to perform the operations based on the S1710 to S1720 and SIB reception steps.

[0373] The embodiments described below are specifically described in terms of base station operation.

[0374] The S1810 to S1820 and SIB transmission steps described below correspond to the S1710 to S1720 and SIB reception steps described in FIG. 17. Considering the above correspondence, redundant descriptions are omitted. That is, the specific description of the base station operation described below may be replaced with the description / embodiment of FIG. 17 corresponding to the operation. For example, the description / embodiment of S1710 to S1720 of FIG. 17 may be additionally applied to the base station operation of S1810 to S1820 described below. For example, the description / embodiment of the terminal operation of the SIB reception step may be additionally applied to the base station operation of the SIB transmission step described below.

[0375] FIG. 18 is a flowchart illustrating a method performed by a base station according to another embodiment of the present specification.

[0376] Referring to FIG. 18, a method performed by a base station according to another embodiment of the present specification includes a RACH configuration transmission step (S1810) and a PRACH reception step (S1820).

[0377] In step S1810, the base station transmits a Random Access Channel (RACH) configuration to the terminal. For example, the RACH configuration may include information based on the configuration / operation related to the above-described random access preamble.

[0378] In step S1820, the base station receives a Physical Random Access Channel (PRACH) from the terminal based on sets. For example, the reception of the PRACH may be performed based on the settings / operations related to the random access preamble described above.

[0379] In one embodiment, the method may further include a SIB transmission step. Specifically, the base station transmits a System Information Block (SIB) to the terminal. The SIB may include settings related to frequency hopping. The SIB transmission step may be performed prior to S1810.

[0380] The operations based on the S1810 to S1820 and SIB transmission steps described above can be implemented by the device of FIG. 19. For example, the base station (100) can control one or more transceivers (130) and / or one or more memories (140) to perform operations based on the S1810 to S1820 and SIB transmission steps.

[0381] Hereinafter, a device to which an embodiment of the present specification can be applied (a device that implements a method / operation according to an embodiment of the present specification) is described with reference to FIG. 19.

[0382] FIG. 19 is a drawing showing the configuration of the first device and the second device according to an embodiment of the present specification.

[0383] The first device (100) may include a processor (110), an antenna unit (120), a transceiver (130), and a memory (140).

[0384] The processor (110) performs baseband-related signal processing and may include a higher layer processing unit (111) and a physical layer processing unit (115). The higher layer processing unit (111) may process operations of a MAC layer, an RRC layer, or higher layers. The physical layer processing unit (115) may process operations of a PHY layer. For example, when the first device (100) is a base station device in base station-terminal communication, the physical layer processing unit (115) may perform uplink reception signal processing, downlink transmission signal processing, etc. For example, when the first device (100) is a first terminal device in terminal-to-terminal communication, the physical layer processing unit (115) 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 (110) may also control the overall operation of the first device (100).

[0385] The antenna unit (120) may include one or more physical antennas, and when it includes multiple antennas, it may support MIMO transmission and reception. The transceiver (130) may include an RF (Radio Frequency) transmitter and an RF receiver. The memory (140) may store information processed by the processor (110), and software, an operating system, applications, etc. related to the operation of the first device (100), and may also include components such as a buffer.

[0386] The processor (110) of the first device (100) 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.

[0387] The second device (200) may include a processor (210), an antenna unit (220), a transceiver (230), and a memory (240).

[0388] The processor (210) performs baseband-related signal processing and may include a higher layer processing unit (211) and a physical layer processing unit (215). The higher layer processing unit (211) may process operations of a MAC layer, an RRC layer, or higher layers. The physical layer processing unit (215) may process operations of a PHY layer. For example, when the second device (200) is a terminal device in base station-terminal communication, the physical layer processing unit (215) may perform downlink reception signal processing, uplink transmission signal processing, etc. For example, when the second device (200) is a second terminal device in terminal-to-terminal communication, the physical layer processing unit (215) 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 (210) may also control the overall operation of the second device (210).

[0389] The antenna unit (220) may include one or more physical antennas, and when it includes multiple antennas, it may support MIMO transmission and reception. The transceiver (230) may include an RF transmitter and an RF receiver. The memory (240) may store information processed by the processor (210), software, an operating system, applications, etc. related to the operation of the second device (200), and may also include components such as a buffer.

[0390] The processor (210) of the second device (200) 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.

[0391] In the operation of the first device (100) and the second device (200), 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 redundant explanations are omitted.

[0392] Here, the wireless communication technology implemented in the device (100, 200) of the present disclosure may include not only LTE, NR, and 6G, but also Narrowband Internet of Things (NB-IoT) for low-power communication. For example, NB-IoT technology may be an example of LPWAN (Low Power Wide Area Network) technology, and may be implemented in standards such as LTE Cat NB1 and / or LTE Cat NB2, and is not limited to the above-described names.

[0393] Additionally or alternatively, the wireless communication technology implemented in the device (100, 200) of the present disclosure may perform communication based on LTE-M technology. For example, LTE-M technology may be an example of LPWAN technology and may be called by various names such as eMTC (enhanced Machine Type Communication). For example, LTE-M technology may be implemented by at least one of various standards such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL (non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine Type Communication, and / or 7) LTE M, and is not limited to the above-described names.

[0394] Additionally or alternatively, the wireless communication technology implemented in the device (100, 200) of the present disclosure may include at least one of ZigBee, Bluetooth, and Low Power Wide Area Network (LPWAN) that take low-power communication into account, and is not limited to the above-described names. For example, ZigBee technology can create personal area networks (PANs) related to small / low-power digital communication based on various standards such as IEEE 802.15.4, and may be called by various names.

Claims

1. In a method performed by a terminal, A step of receiving a Random Access Channel (RACH) setting; and A step of transmitting a Physical Random Access Channel (PRACH) based on sets; comprising: Each of the above sets contains PRACH occasions based on the number of repetitions, The above sets include a first set and a second set related to frequency hopping, A method characterized in that the first set and the second set are determined based on the order of the time resource index and / or frequency resource index of the first PRACH occasion within each set among the sets within a time period.

2. In paragraph 1, A method characterized in that the second set is determined in ascending order of the time resource index from the first set having the lowest frequency resource index among the sets within the time interval.

3. In paragraph 2, Based on the fact that there is no set based on the time resource index greater than the time resource index based on the first set among the above sets: A method characterized in that the second set is determined in ascending order of the frequency resource index from the first set.

4. In paragraph 1, A method characterized in that the frequency hopping is performed based on i) a first PRACH occasion selected from the first set or the second set and ii) a second PRACH occasion selected from the second set or the first set.

5. In paragraph 4, A method characterized in that the second PRACH occasion is located after the first PRACH occasion in the time domain.

6. In paragraph 1, The above sets include i) the first set and the second set and / or ii) the third set, A method characterized in that the third set includes the PRACH occasions associated with the frequency hopping.

7. In paragraph 6, The frequency hopping associated with the third set is performed based on indices associated with the number of repetitions, A method characterized in that, in the third set, a frequency resource index of a PRACH occasion based on one of the indices is different from a frequency resource index of a PRACH occasion based on a next index of the indices.

8. In paragraph 1, Further comprising the step of receiving a System Information Block (SIB), A method characterized in that the SIB includes settings related to the frequency hopping.

9. In paragraph 8, A method characterized in that the setting related to the frequency hopping includes i) information indicating whether the frequency hopping is enabled, ii) information related to determination of the first set and the second set, and / or iii) information related to determination of a PRACH occasion for the frequency hopping.

10. In the terminal, One or more transmitters and receivers; one or more processors; and One or more memories connected to said one or more processors and storing instructions, A terminal characterized in that the instructions are set to cause the one or more processors to perform all steps of the method according to any one of claims 1 to 9, based on being executed by the one or more processors.

11. In a device comprising one or more memories and one or more processors functionally connected to the one or more memories, A device characterized in that said one or more memories store instructions that cause said one or more processors to perform all steps of a method according to any one of claims 1 to 9, based on being executed by said one or more processors.

12. In one or more non-transitory computer-readable media storing instructions, One or more non-transitory computer-readable media characterized in that the instructions executable by one or more processors cause the one or more processors to perform all steps of the method according to any one of claims 1 to 9.

13. In a method performed by a base station, A step of transmitting a Random Access Channel (RACH) setting; and A step of receiving a Physical Random Access Channel (PRACH) based on sets; comprising: Each of the above sets contains PRACH occasions based on the number of repetitions, The above sets include a first set and a second set related to frequency hopping, A method characterized in that the first set and the second set are determined based on the order of the time resource index and / or frequency resource index of the first PRACH occasion within each set among the sets within a time period.

14. At the base station, One or more transmitters and receivers; one or more processors; and One or more memories connected to said one or more processors and storing instructions, A base station characterized in that the instructions are set to cause the one or more processors to perform all steps of the method according to claim 13, based on the instructions being executed by the one or more processors.

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