Method and apparatus for transmitting and receiving random access preambles in wireless communication systems

Abstract

A method according to one embodiment of this specification includes the steps of receiving a RACH setting and transmitting a Random Access Preamble based on a repetition number associated with a feature combination. The RACH setting includes a plurality of preamble settings. Each of the plurality of preamble settings is associated with a feature combination. The repetition number is one of a plurality of repetition numbers based on the plurality of preamble settings.

Description

Technical Field

[0001] This specification relates to a method and apparatus for transmitting and receiving a random access preamble in a wireless communication system.

Background Art

[0002] Mobile communication systems were developed to provide voice services while ensuring user mobility. However, mobile communication systems have expanded their scope to include not only voice but also data services, and currently, due to the explosive increase in traffic, a shortage of resources has occurred, and users are demanding faster services, so more advanced mobile communication systems are required.

[0003] The requirements for next-generation mobile communication systems are great, and they must support the accommodation of explosive data traffic, a revolutionary increase in the transmission rate per user, the accommodation of a greatly increased number of connected devices, a very low end-to-end latency, and high energy efficiency. Therefore, various technologies such as dual connectivity, massive multiple input multiple output (Massive MIMO), in-band full duplex, non-orthogonal multiple access (NOMA), super wideband support, and device networking are being studied.

[0004] On the other hand, according to Rel-17 feature combinations, a specific RACH resource partitioning can have only one feature or a combination of multiple features. In Rel-18, features related to MSG1 repetition are supported. In this case, a repetition number (2, 4, or 8) can be set. In this case, among the preamble indices, only one repetition number can be set / applied to the preamble index to which the MSG1 repetition feature is applied. [Overview of the project] [Problems that the invention aims to solve]

[0005] Using a fixed repetition number for all preambles to which the aforementioned MSG1 repetition feature applies can be inefficient.

[0006] This specification proposes a method for solving the aforementioned problems.

[0007] The technical problems to be addressed in this specification are not limited to those mentioned above, and other technical problems not mentioned should be clearly understood by those skilled in the art to which the present invention pertains from the following description. [Means for solving the problem]

[0008] A method performed by a terminal according to one embodiment of this specification includes the steps of receiving a Random Access Channel (RACH) setting and transmitting a Random Access Preamble based on a repetition number associated with a feature combination.

[0009] The RACH setting includes multiple preamble settings. Each of the multiple preamble settings is associated with a feature combination. The number of iterations is one of a plurality of iterations based on the multiple preamble settings.

[0010] The number of repetitions can be determined from among the plurality of repetitions based on the Reference Signal Received Power (RSRP).

[0011] The RACH setting may include a RACH setting based on a Bandwidth Part (BWP) - uplink common setting.

[0012] The RACH setting may include i) the RACH setting within the BWP-uplink common setting and ii) the RACH setting based on each additional RACH setting within the BWP-uplink common setting.

[0013] Each preamble setting based on the RACH setting may include information about the set of preambles. In the bandwidth portion (BWP), there may be at most one set of preambles associated with each of the multiple iteration counts.

[0014] The aforementioned multiple repetition counts can be based on different values.

[0015] Based on the feature combination, one or more features may be specified. These one or more features may include MSG1 repetitions.

[0016] The multiple iteration counts can be set based on a preamble configuration that includes the feature combination associated with the MSG1 repetitions.

[0017] The aforementioned number of iterations may be associated with a shared random access channel opportunity (RACH Occasion, RO).

[0018] The number of repetitions may be 2, 4, or 8.

[0019] A terminal according to another embodiment of this specification includes one or more transceivers, one or more processors, and one or more memories connected to the one or more processors for storing instructions.

[0020] The instruction is characterized in that, based on the fact that it is executed by one or more processors, it is configured so that one or more processors execute all the steps of any one of the methods.

[0021] Apparatus according to other embodiments of this specification includes one or more memories and one or more processors functionally connected to the one or more memories.

[0022] The one or more memories are configured to store instructions that, when executed by the one or more processors, cause the one or more processors to execute all steps of any one of the methods.

[0023] One or more non-transitory computer-readable media according to other embodiments herein store instructions. The instructions executable by one or more processors are configured to cause the one or more processors to execute all steps of any one of the methods.

[0024] A method performed by a base station according to yet other embodiments herein includes transmitting Random Access Channel (RACH) configuration and receiving a Random Access Preamble based on a repetition number associated with a feature combination.

[0025] The RACH configuration includes a plurality of preamble configurations. Each of the plurality of preamble configurations is associated with one feature combination. The repetition number is one of a plurality of repetition numbers based on the plurality of preamble configurations.

[0026] A base station according to yet another embodiment herein includes one or more transceivers, one or more processors, and one or more memories connected to the one or more processors and storing instructions.

[0027] The instructions are configured to cause the one or more processors to execute all steps of the method when executed by the one or more processors.

Advantages of the Invention

[0028] According to the embodiments of this specification, the random access preamble can be executed based on one of multiple repetition counts. Therefore, since various repetition counts can be supported for the same feature (MSG1 repetition), the repeated transmission of the random access preamble can be executed based on the repetition count that best suits the channel quality.

[0029] Also, the signaling overhead of the RACH procedure can be reduced compared to the case where a fixed repetition count is set / used. For example, when the channel state is good, unnecessary signaling overhead is generated when the random access preamble repeated transmission is performed based on a large number of repetition counts. According to the embodiments of this specification, since the repeated transmission can be executed based on the repetition count that suits the channel state, the RACH procedure can be improved in terms of signaling overhead.

[0030] The effects obtained in this specification are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those with ordinary knowledge in the technical field to which this specification belongs from the following description.

Brief Description of the Drawings

[0031] [Figure 1] Exemplify the physical channels and general signal transmissions used in the 3GPP (registered trademark; the same hereinafter) system. [Figure 2] Show RACH occasions by preamble format. [Figure 3] Exemplify the random access procedure. [Figure 4] Exemplify RRC parameters related to RACH partitioning. [Figure 5-9]This example illustrates how to set the repetition number based on additional RACH configuration. [Figure 10-15] This example illustrates how to set the repetition number based on a feature combination. [Figure 16] This is a flowchart illustrating a method performed by a terminal according to one embodiment of this specification. [Figure 17] This is a flowchart illustrating a method performed by a base station according to other embodiments of this specification. [Figure 18] This figure shows the configurations of the first and second apparatus according to embodiments of this specification. [Modes for carrying out the invention]

[0032] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The detailed description disclosed below, together with the accompanying drawings, is intended to describe exemplary embodiments of the present invention and not to show only the embodiments in which the invention can be carried out. The following detailed description includes specific details in order to provide a complete understanding of the invention. However, those skilled in the art will see that the invention can be carried out without such specific details.

[0033] In some cases, known structures and devices may be omitted or shown in the form of block diagrams focusing on the core function of each structure and device, in order to avoid ambiguity of the concept of the present invention.

[0034] In the following, 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, the transmitter can be part of the base station, and the receiver can be part of the terminal. In uplink, the transmitter can be part of the terminal, and the receiver can be part of the base station. The base station can also be described as the first communication device, and the terminal as the second communication device. The term base station (BS) can be replaced with terms such as fixed station, Node B, eNB (evolved-Node B), gNB (Next Generation Node B), BTS (base transceiver system), access point (AP), network (5G network), AI system, RSU (roadside unit), vehicle, robot, drone (unmanned aerial vehicle, UAV), AR (Augmented Reality) device, and VR (Virtual Reality) device. Furthermore, a terminal can be fixed or mobile, and can 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) equipment, M2M (Machine-to-Machine) equipment, D2D (Device-to-Device) equipment, vehicle, robot, AI module, drone (Unmanned Aerial Vehicle, UAV), AR (Augmented Reality) equipment, and VR (Virtual Reality) equipment.

[0035] Physical channels and general signal transmission

[0036] Figure 1 illustrates the physical channels and typical signal transmissions used in 3GPP systems. In wireless communication systems, terminals receive information from base stations via the downlink (DL) and transmit information to base stations via the uplink (UL). The information transmitted and received between base stations and terminals includes data and various control information, and various physical channels exist depending on the type and purpose of the information being transmitted and received.

[0037] When a terminal is powered on or enters a new cell, it performs initial cell search operations, such as synchronizing with the base station (S101). To do this, 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 the cell ID. Subsequently, the terminal receives the Physical Broadcast Channel (PBCH) from the base station to obtain broadcast information within the cell. Meanwhile, the terminal receives a Downlink Reference Signal (DLRS) during the initial cell search step to check the downlink channel status.

[0038] After completing the initial cell search, the terminal can obtain more specific system information by receiving the Physical Downlink Control Channel (PDCCH) and the Physical Downlink Shared Channel (PDSCH) via the information carried on the PDCCH (S102).

[0039] On the other hand, if the terminal is initially connected to a base station or does not have radio resources for signal transmission, it can perform a Random Access Procedure (RACH) with respect to the base station (S103-S106). To do this, the terminal transmits a specific sequence in the preamble via a Physical Random Access Channel (PRACH) (S103 and S105), and can receive a Random Access Response (RAR) message for the preamble via the PDCCH and the corresponding PDSCH. In the case of a competitive RACH, an additional Contention Resolution Procedure can be performed (S106).

[0040] A terminal that has performed the procedures described above can then perform general uplink / downlink signal transmission procedures, such as PDCCH / PDSCH reception (S107) and Physical Uplink Shared Channel (PUSCH) / Physical Uplink Control Channel (PUCCH) transmission (S108). In particular, the terminal can receive Downlink Control Information (DCI) via PDCCH. Here, DCI includes control information such as resource allocation information for the terminal, and its format can be applied in different ways depending on its intended use.

[0041] On the other hand, control information that a terminal transmits to or receives from a base station via the uplink may include downlink / uplink ACK / NACK signals, CQI (Channel Quality Indicator), PMI (Precoding Matrix Index), RI (Rank Indicator), etc. The terminal can transmit the aforementioned control information such as CQI / PMI / RI via PUSCH and / or PUCCH.

[0042] Next, I will explain the RACH traction.

[0043] A RACH slot contains one or more RACH occasion(s).

[0044] The slot duration is 1 ms for {1.25 kHz, 5 kHz} subcarrier spacings, and has scalable durations (i.e., 1 ms, 0.5 ms, 0.25 ms, 0.125 ms) for {15 kHz, 30 kHz, 60 kHz, 120 kHz} subcarrier spacings.

[0045] For short preamble formats, the OFDM symbol index starting with the RACH slot has {0, 2, x} values.

[0046] Figure 2 shows RACH occasions by preamble format.

[0047] As shown in Figure 2, a RACH slot can contain one or more RACH occasions (ROs) for each preamble format (e.g., A1, A2, ...C2). Figure 2(a) shows the case where the starting OFDM symbol is "0", and Figure 2(b) shows the case where the starting OFDM symbol is "2".

[0048] Figure 3 illustrates a random access procedure.

[0049] Figure 3(a) shows a contention-based RACH procedure, and Figure 3(b) shows a contention-free RACH procedure.

[0050] The following explains how to send an MSG1.

[0051] The subcarrier spacing for MSG1 is set in the RACH configuration and provided in the handover instruction for non-competitive RA procedures for handover.

[0052] The preamble indices for CBRA (contention-based random access) and CFRA (contention-free random access) are sequentially mapped to one SSB per RACH transmission occasion.

[0053] Within a CBRA:SS burst set, the relationships between SS blocks (SSBs) and subsets such as RACH resources and / or preamble indices are defined by a parameter set in RMSI.

[0054] CFRA:UE can be configured to send multiple MSG1s via a dedicated multiple RACH transmission opportunity in the time domain before the end of the monitored RAR window.

[0055] The connection between the CFRA preamble and the SSB is then re-established via the UE-specific RRC.

[0056] A random access procedure can be either a Type-1 random access procedure (4-step RA) or a Type-2 random access procedure (2-step RA).

[0057] The aforementioned Type-1 random access procedure may include sending a random access preamble (Msg1) on a physical random access channel (PRACH), receiving a random access response (RAR) (Msg2), sending a PUSCH scheduled by the UL grant of the RAR (Msg3), and performing 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.

[0058] The aforementioned Type-2 random access procedure may include sending a random access preamble and a PUSCH (MsgA) and receiving a RAR (MsgB).

[0059] Table 1 illustrates the settings and operations associated with random access preambles.

[0060] [Table 1]

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[0065] JPEG2026515671000007.jpg201148

[0066] The settings / definitions / operations described in Table 1 above may be referenced to clarify the definitions / operations of the embodiments described later. For example, in the embodiments described later, RO may mean a valid PRACH occasion as mentioned in Table 1. For example, in the embodiments described later, multiple ROs having the same beam index may mean 1 / N (where N < 1) consecutive valid PRACH occasions mapped to one SS / PBCH index.

[0067] Tables 2 to 4 below illustrate PRACH configuration tables that can be applied to embodiments described later.

[0068] [Table 2]

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[0070] JPEG2026515671000010.jpg211149

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[0077] Table 3

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[0086] Table 4

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[0099] For example, in the embodiments described later, RO may be an RO based on one of Tables 2 to 4.

[0100] The aforementioned information can be applied in combination with the method proposed herein, as described later, or can be supplemented to clarify the technical features of the method proposed herein.

[0101] Furthermore, the methods related to the PRACH transmission occasion configuration described later are related to uplink transmission and can be similarly applied to the uplink signal transmission methods in the aforementioned NR system (licensed band) or U-Band system (unlicensed band). It goes without saying that the technical ideas proposed herein can be realized in such systems as well, and can be modified or substituted to suit the terminology, expressions, structures, etc., defined in each system.

[0102] For example, uplink transmission via methods associated with the PRACH transmission occasion configuration described later can be performed in L-cells (cells operating in the licensed band (L-band)) and / or U-cells (cells operating in the unlicensed band (U-band)) as defined in the NR system or U-Band system.

[0103] NR supports multiple numerologies (or subcarrier spacings (SCS)) to support various 5G services. For example, an SCS of 15kHz supports wide area in traditional cellular bands, an SCS of 30kHz / 60kHz supports dense-urban, lower latency, and wider carrier bandwidth, and an SCS of 60kHz or higher supports bandwidths greater than 24.25GHz to overcome phase noise.

[0104] The NR frequency band is defined as a frequency range of two types (FR1, FR2). FR1 and FR2 can be configured as shown in Table 5 below. Furthermore, FR2 can refer to millimeter waves (mmW).

[0105] [Table 5]

[0106] In the following, when the PRACH repetition scheme is introduced in NR for coverage enhancement, we propose a RACH resource partitioning method for PRACH repetition and related terminal / base station operations. In this specification, "PRACH transmission," "RACH transmission," or "preamble transmission" may be interpreted / substituted for "MSG1 transmission."

[0107] Various RAN1 work items are defined to allow for the differentiation of terminal / base station operations based on RACH resources (e.g., PRACH preamble index). For example, terminals related to redcap, small data transmission, and Msg.3PUSCH repetition are defined to request the base station to use the corresponding feature by selecting a specific preamble index during the PRACH preamble transmission step. However, defining separate operations for each work item in this way can increase the complexity of terminal / base station implementation.

[0108] Therefore, the concept of "Feature Combination" was introduced in the RAN2 Rel-17 RACH partitioning work item to efficiently support terminal / base station operations that require partitioning using RACH resources (e.g., PRACH preamble index). That is, the base station sets specific PRACH resources (e.g., preamble start index and total number indication) to set / instruct terminals that a specific feature or combination of features is supported. A terminal that intends to use / request a specific feature and / or combination of features can, during the execution of the RACH procedure, select one of the preamble indices of the area allocated to the specific feature and / or combination of features it desires and transmit the PRACH preamble. The RRC parameters for this operation may be "FeatureCombinationPreambles" and "FeatureCombination". Table 6 below illustrates the aforementioned "FeatureCombinationPreambles" and "FeatureCombination".

[0109] [Table 6]

[0110] Multiple FeatureCombinationPreambles parameters can be set within RACH-ConfigCommon. The preamble index intervals corresponding to each region (i.e., regions / partitions based on preamble(s) belonging to each of the multiple FeatureCombinationPreambles parameters) must be set so as not to overlap. In addition, the features and / or feature combinations set in each region must also be set so as not to overlap with each other. As described above, parameters for random access procedures can be initialized / determined based on the RACH resource (e.g., preamble) selected by the terminal.

[0111] In this specification, “RACH resource” (or “PRACH resource”) may be interpreted / substituted as “Random access resource.” For example, a Featurecombination associated with a RACH resource (e.g., a feature or combination of features) may be interpreted / substituted as a Featurecombination associated with a set of Random access resources.

[0112] On the other hand, in addition to the RACH-ConfigCommon assigned to the existing BWP-UplinkCommon, the base station can further assign RACH configurations via AdditionalRACH-Config-r17. The BWP-UplinkCommon can be configured based on an SIB (e.g., SIB1). The RACH procedure can be performed by a Rel-16 terminal / Rel-17 terminal as follows:

[0113] For Rel-16 terminals that cannot read AdditionalRACH-Config-r17, the terminal will execute the RACH procedure based on the RACH-ConfigCommon assigned to the existing BWP-UplinkCommon.

[0114] For terminals running Rel-17 or later that can read AdditionalRACH-Config-r17, the terminal will check the RACH-ConfigCommon assigned to the existing BWP-UplinkCommon and the RACH-ConfigCommon assigned to AdditionalRACH-Config-r17, and then execute the RACH procedure.

[0115] Furthermore, one or more of the aforementioned FeatureCombinationPreambles may be configured in the RACH-ConfigCommon assigned to the existing BWP-UplinkCommon. One or more of the aforementioned FeatureCombinationPreambles may also be configured in the RACH-ConfigCommon assigned to AdditionalRACH-Config-r17. The following explanation will be given with reference to Figure 4.

[0116] Figure 4 shows the RRC parameters related to RACH partitioning. Specifically, Figure 4 shows the connection relationships / hierarchical relationships of the RRC parameters related to RACH partitioning.

[0117] Refer to Figure 4 for a detailed explanation of each parameter. For convenience of explanation, RRC parameters (e.g., BWP-UplinkCommon parameters) will be referred to by their parameter names (e.g., BWP-UplinkCommon).

[0118] BWP-UplinkCommon includes i) RACH-ConfigCommon, ii) msgA-ConfigCommon, and iii) one or more AdditionalRACH-Configs (#1, #2, etc.).

[0119] Each AdditionalRACH-Config includes i) rach-ConfigCommon and ii) msgA-ConfigCommon.

[0120] Each `rach-ConfigCommon` contains one or more `FeatureCombinationPreambles`.

[0121] Each FeatureCombinationPreamble contains a FeatureCombination.

[0122] Table 7 shows examples of the RRC parameters mentioned above.

[0123] [Table 7]

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[0131] On the other hand, the introduction of PRACH preamble repetition transmission is being considered to enhance the UL coverage of existing NR systems. Therefore, in order to support PRACH repetition, it is necessary to define how to allocate PRACH resources that have different repetition counts. Accordingly, this specification proposes a PRACH resource partitioning method and related terminal / base station operations when PRACH repetition is introduced into an NR system.

[0132] Below, we will carefully examine how to allocate RACH resources for multiple PRACH repetitions.

[0133] Several methods have been considered for allocating PRACH repetition resources with different repetition counts. In this case, a method can be considered for allocating RACH resources so that they are divided into preamble level or RO level among multiple PRACH repetition resources with different repetition counts, and a related method is proposed as follows.

[0134] [Method 1]

[0135] Below, we will carefully examine how multiple PRACH repetition resources with different repetition counts are allocated using a separated RO method based on the additional RACH configuration.

[0136] A. The base station can set / instruct the repetition number as follows: The repetition number may be set / instructed based on RACHcommonconfig or FeatureCombinationPreambles. For example, a parameter (e.g., RACH-commonconfig) within each additional RACH configuration (e.g., AdditionalRACH-Config-r17) may include a repetition number. For example, RACH partitioning (e.g., FeatureCombinationPreambles) within RACH-commonconfig may include a repetition number.

[0137] i. As a specific example, the configured / instructed repetition number can be one of {1, 2, 4, 8}. The terminal can perform single or multiple RACH transmissions depending on the configured / instructed repetition number from the base station.

[0138] ii. As another example, the set / instructed repetition number can be one of {2, 4, 8}. If the base station does not set / instruct a repetition number, the repetition number may be implicitly instructed as 1. For example, a terminal can perform a multiple RACH transmission according to the repetition number set / instructed by the base station. If the base station does not instruct a repetition number (e.g., there is no value for repetition number to instruct, or the repetition number parameter is absent), the terminal can perform a single RACH transmission.

[0139] In the following sections, the setting of the repetition number will be explained in detail with reference to Figures 5 to 9.

[0140] Figures 5 to 9 illustrate the setting of the repetition number based on the additional RACH configuration.

[0141] Alt 1-1)

[0142] Each additional RACH configuration that sets up / instructs multiple RACH transmissions can be defined to always instruct a different repetition number from one another.

[0143] i. It can be assumed that the base station allocates single RACH resources and multiple RACH resources based on a separated RO scheme. That is, if the legacy RACH configuration does not specify a repetition number, the repetition number (repetition factor) can be assigned as shown in Figure 5. Referring to Figure 5, the repetition number based on each AdditionalRACHconfig is A, B, or C. FC stands for feature combination. For example, a terminal can select a RACH configuration that matches the repetition number determined based on the RSRP and execute the RACH procedure. As an example, the repetition number may be determined to be 2, 4, or 8 based on the fact that the RSRP is lower than the RSRP threshold (for repetition number 2 / 4 / 8).

[0144] ii. It can be assumed that the base station allocates single RACH resources and multiple RACH resources in a separated preamble in shared RO manner. That is, if the legacy RACH configuration also indicates a repetition number, the following embodiments may apply.

[0145] Alt 1-1-1)

[0146] As shown in Figure 6, the repetition number indicated in the legacy RACH configuration can be defined to always be different from the repetition number value indicated in the additional RACH configuration. Referring to Figure 6, the repetition number based on the legacy RACH configuration is A, and the repetition number based on each AdditionalRACHconfig is B or C. For example, a terminal can select a RACH configuration that matches the number of repetitions (repetition number) determined based on the RSRP and execute the RACH procedure. As an example, the repetition number may be determined to be 2, 4, or 8 based on the RSRP being lower than the RSRP threshold (for repetition number 2 / 4 / 8).

[0147] Alt 1-1-2)

[0148] As shown in Figure 7, regardless of the repetition number value indicated in the legacy RACH configuration, the repetition number values ​​indicated based on each additional RACH configuration may be defined to be set / instructed to be different from one another.

[0149] A. If two RACH resources have the same repetition number (e.g., the repetition number is the same between a legacy RACH configuration and a specific additional RACH configuration), and the terminal decides to select the corresponding repetition number via RSRP or the like, the following embodiments may apply.

[0150] Alt 1-1-2-A)

[0151] The terminal can select a RACH resource based on a configured / instructed / defined probability value. For example, the probability value may be configured / instructed / defined as follows:

[0152] p = legacy RACH configuration selection probability

[0153] 1-p = probability of selecting an additional RACH configuration (0≦p≦1)

[0154] Alt 1-1-2-B)

[0155] The terminal can randomly select a RACH resource.

[0156] Alt 1-2)

[0157] The same repetition number may be set / indicated based on two or more additional RACH configurations and / or legacy RACH configurations.

[0158] i. There may be two RACH resources with the same repetition number (e.g., the same repetition number based on a legacy RACH configuration and / or multiple additional RACH configurations). Specifically, referring to Figure 8, the repetition number based on the legacy RACH config, Additional RACH config#0, and Additional RACH config#1 is A. If the terminal decides to select the corresponding repetition number via RSRP or the like, the following embodiments may apply.

[0159] Alt 1-2-A)

[0160] The terminal can select a RACH resource based on a configured / instructed / defined probability value. For example, the probability value may be configured / instructed / defined as follows:

[0161] p = legacy RACH configuration selection probability

[0162] (1-p) / N = probability of selecting one out of N additional RACH configurations (0≦p≦1)

[0163] Alt 1-2-B)

[0164] The terminal can randomly select a RACH resource.

[0165] The following section will specifically explain how to set parameters for feature combinations.

[0166] i.Alt A) Parameters for feature combinations can be set commonly for msg.1 repetition regardless of the repetition number. For example, a new parameter may be introduced (e.g., msg.1 Repetition R18). For example, an existing parameter (e.g., msg.3 repetition R17) may be reused and configured to support up to the PRACH repetition.

[0167] ii. Alt B) As shown in Figure 9, the parameters for the Feature combination can be set to different parameters for each repetition number. For example, the parameters for the Feature combination can be defined to include the repetition number value (e.g., msg. 1 Repetition A, msg. 1 Repetition B, msg. 1 Repetition C). In this embodiment, the base station does not need to separately specify the repetition number value in the RACH configuration, but the parameters for the Feature combination should be set to multiple values.

[0168] As an example, different features can be introduced for each repetition number (e.g., R = A, B, C) as shown in Table 8 below (in this case, A, B, and C can be one of 2, 4, or 8).

[0169] [Table 8]

[0170] As described above, the base station can set / instruct the terminal to configure / perform PRACH resource partitioning corresponding to each repetition number through the feature combination method, while setting the repetition numbers to different features.

[0171] Characteristically, the terminal can expect that no multiple RACH partitionings are configured within a particular additional RACH configuration, each containing multiple PRACH features with different repetition numbers. If such multiple RACH partitionings are configured, the terminal can determine that the configuration is invalid.

[0172] In addition, the terminal can expect that RACH partitioning consisting of feature combinations between multiple PRACH features with different repetition numbers will not be configured within a specific additional RACH configuration. If such a configuration is made, the terminal can determine that it is an invalid configuration.

[0173] When different repetition counts are assigned using the separated RO method, the probability of collisions between terminals using a specific repetition count can be reduced compared to when they are assigned using the separated preamble in shared RO method.

[0174] [Method 2]

[0175] Below, we carefully examine how to allocate multiple PRACH repetition resources with different repetition counts using a separated preamble in shared RO method based on the feature combination method.

[0176] A. In order to assign different number of repetitions using the Separated Preamble in Shared RO method, it is necessary to define that they are separated by a specific preamble level within the RACH configuration.

[0177] Alt 2-1)

[0178] One possible approach is to consider a method where parameters for feature combinations are set commonly for msg.1 repetitions, regardless of the repetition number. [

[0179] In the prior art, it is not supported to assign multiple RACH partitionings with the same feature or feature combination within a given RACH configuration.

[0180] Alt 2-1-1)

[0181] If Rel-18 CE supports assigning multiple RACH partitionings with the same feature or feature combination within a given RACH configuration, the following embodiments may apply.

[0182] Alt 2-1-1-1)

[0183] The base station can set / instruct different repetition numbers for each RACH partitioning corresponding to the PRACH repetition feature (e.g., Msg. 1 Repetition R18) and / or feature combination including the relevant feature.

[0184] A. That is, as shown in Figure 10, different repetition numbers may be set for each RACH partitioning (e.g., FeatureCombinationPreambles). Each RACH partitioning (e.g., FeatureCombinationPreambles) can be based on FeatureCombinationPreambles included in each of the RACH-commonconfigs (e.g., RACH-ConfigcCommon in Figure 4). Referring to Figure 4, the RACH-commonconfig may include i) FeatureCombinationPreambles based on a legacy RACH configuration (rach-ConfigCommon based on BWP-UplinkCommon) and / or ii) FeatureCombinationPreambles based on each AdditionalRACH-Config.

[0185] In this case, a PRACH repetition feature (e.g., Msg. 1 Repetition R18) and / or a feature combination including the relevant feature may be set based on the corresponding RACH partitioning (e.g., FeatureCombinationPreambles).

[0186] Alt 2-1-1-2)

[0187] The base station can arbitrarily set / instruct a repetition number for each RACH partitioning corresponding to a PRACH repetition feature (e.g., Msg. 1 Repetition R18) and / or a feature combination containing the relevant feature. In other words, the base station can set / instruct the same repetition number for multiple RACH partitionings.

[0188] A. That is, as shown in Figure 11, an (arbitrary) repetition number can be set for each RACH partitioning (e.g., FeatureCombinationPreambles). In other words, unlike Alt 2-1-1-1), an arbitrary repetition number can be said to be not limited to repetition numbers that are different from each other. For example, a repetition number (A) set based on one RACH partitioning (e.g., RACH partitioning based on the legacy RACH configuration in Figure 11) may be the same as a repetition number (A) set based on another RACH partitioning (e.g., RACH partitioning based on Addition RACH Config#0 in Figure 11).

[0189] Each RACH partitioning (e.g., FeatureCombinationPreambles) can be based on FeatureCombinationPreambles contained in each of the RACH-commonconfigs (e.g., rach-ConfigcCommon in Figure 4). Referring to Figure 4, the RACH-commonconfig can include i) FeatureCombinationPreambles based on a legacy RACH configuration (rach-ConfigCommon based on BWP-UplinkCommon) and / or ii) FeatureCombinationPreambles based on each AdditionalRACH-Config.

[0190] i. In this case, a PRACH repetition feature (e.g., Msg.1 Repetition R18) and / or a feature combination including the relevant feature may be set based on the corresponding RACH partitioning (e.g., FeatureCombinationPreambles).

[0191] The following embodiments may apply to the selection of RACH partitioning.

[0192] Alt 2-1-1-2-A)

[0193] The terminal can select RACH partitioning based on a configured / specified probability value. As an example, the probability value may be configured / specified / defined as follows:

[0194] p / M = probability of selecting one of M partitionings in a legacy RACH configuration.

[0195] (1-p) / N = Probability of selecting one of N partitionings in the additional RACH configuration.

[0196] Alt 2-1-1-2-B)

[0197] The terminal can randomly select RACH partitioning.

[0198] Alt 2-1-2)

[0199] If (while maintaining the existing scheme) RACH partitioning with the same feature or feature combination does not support multiple allocations within a particular RACH configuration, the following embodiments may apply.

[0200] Alt 2-1-2-1)

[0201] A method can be considered for dividing the preamble index interval (i.e., the starting preamble index and / or the number of preamble indices) by repetition number based on a predefined formula.

[0202] A. The base station sets / instructs the terminal to set one or more repetition numbers in higher layer signaling (e.g., SIB1).

[0203] Characteristically, the repetition number can be set / indicated based on parameters for legacy RACH configuration and / or additional RACH configuration (e.g., RACH-commonconfig).

[0204] A single RACH partitioning may be assigned to a feature combination containing a B.PRACH repetition feature (e.g., Msg. 1 Repetition R18) and / or the feature in question. Depending on the number and value of the repetition numbers indicated via higher layer signaling (e.g., SIB1), the preamble index may be defined to be divided (equally) based on a predefined formula.

[0205] i. As an example, it can be assumed that a total of K repetition numbers (e.g., K=3, R={A, B, C}) are indicated based on higher layer signaling (e.g., SIB1), and that a total of L preamble indices are assigned to the RACH partitioning corresponding to the PRACH repetition feature (e.g., Msg.1 Repetition R18). In this case, the repetition numbers may be set / assigned as shown in Figure 12. This will be explained in detail below.

[0206] 1. Of the preamble indices assigned to RACH partitioning, sail(L / K) preamble indices starting from the lowest preamble index may be defined for use with repetition number A.

[0207] 2. Of the preamble indices assigned to RACH partitioning, sail(L / K) preamble indices (row and index + sail(L / K)) can be defined for use as repetition number B.

[0208] 3. Of the preamble indices assigned to RACHpartitioning, (lowest index + 2 * From ceil(L / K) preamble index, ceil(L / K) preamble indices can be defined for use with repetition number C.

[0209] If repetition number C is used (lowest index + 2 *If ceil(L / K) preamble indices are selected from the ceil(L / K) preamble index, but some of these preamble indices exceed the L preamble indices allocated by the base station, the excess preamble indices can be configured not to be used.

[0210] ii. As a different example, it can be assumed that a total of K repetition numbers (e.g., K = 3, R = {A, B, C}) are indicated based on higher layer signaling (e.g., SIB1), and that the total number of preamble indices assigned to the RACH partitioning corresponding to the PRACH repetition feature (e.g., Msg.1 Repetition R18) is L via startPreambleForThisPartition-r17 and / or numberOfPreamblesPerSSB-ForThisPartition-r17. In this case, the repetition numbers may be set / assigned as shown in Figure 13. This will be explained in detail below.

[0211] 1. Of the preamble index assigned to RACHpartitioning Starting from the lowest preamble index (e.g., startPreambleForThisPartition-r17), floor(L / K) preamble indices can be defined for use with repetition number B.

[0212] 2. Of the preamble indexes assigned to RACHpartitioning (lowest index + floor(L / K)) Floor(L / K) preamble indexes can be defined for use with repetition number B.

[0213] 3. Of the preamble indexes assigned to RACHpartitioning, (lowest index + 2 * From the floor(L / K) preamble index, floor(L / K) preamble indices can be defined for use with repetition number C.

[0214] Repetition number C for use with (lowest index + 2) * After floor(L / K) preamble indexes have been determined from floor(L / K) preamble index, if any of the L preamble indexes are not selected for use as a Repetition number, the following actions / settings may apply.

[0215] For example, the relevant preamble index may be configured not to be used for repeated transmissions.

[0216] For example, the base station can be configured to use the largest (or smallest) repetition number set for the relevant RO, or the relevant preamble index for the example repetition number C.

[0217] iii. As another example, a method can be considered that allows for a more equitable distribution of the number of preamble indices across repetition numbers. The following can be assumed:

[0218] The base station indicates a total of K repetition numbers (e.g., K = 3, R = {A, B, C}) based on higher layer signaling (e.g., SIB1). The total number of preamble indices assigned to the RACH partitioning corresponding to the PRACH repetition feature (e.g., Msg. 1 Repetition R18) by startPreambleForThisPartition-r17 and / or numberOfPreamblesPerSSB-ForThisPartition-r17 is L. Let each preamble index be p_idx (e.g., p_idx = startPreambleForThisPartition-r17, startPreambleForThisPartition-r17+1, startPreambleForThisPartition-r17+2, ..., startPreambleForThisPartition-r17+L-1).

[0219] In the above case, the repetition number can be set / assigned as follows:

[0220] 1. Among the preamble indices assigned to RACH partitioning, preamble indices corresponding to p_idx that satisfy mod(p_idx, K) = 0 may be defined for use with repetition number A.

[0221] 2. Among the preamble indices assigned to RACHpartitioning, preamble indices corresponding to p_idx that satisfy mod(p_idx, K) = 1 may be defined for use as repetition number B.

[0222] 3. Among the preamble indices assigned to RACH partitioning, preamble indices corresponding to p_idx that satisfy mod(p_idx, K) = 2 may be defined for use as repetition number C.

[0223] In the above method, when the number of repetition numbers indicated by the base station based on higher layer signaling (e.g., SIB1, etc.) is a total of K (e.g., K=3, R={A, B, C}), the order of A, B, C can be defined as follows.

[0224] For example, the order of A, B, and C could be the order actually specified by the base station within the relevant parameters (e.g., 1st, 2nd, 3rd, etc.).

[0225] For example, the order of A, B, and C could be in ascending (or descending) order between repetition numbers as instructed by the base station.

[0226] For example, the order of A, B, and C corresponding to the result of mod(p_idx, K) {0, 1, 2} can be defined in advance (e.g., defined so that the value with the largest repetition number maps to the preamble index corresponding to mod(p_idx, K) = 0).

[0227] In particular, the base station can set the L and K values ​​so that the L / K values ​​are always integers (i.e., so that there are no remaining preamble indices using the method described above). That is, the base station can set the L value to be one of the integer multiples of the number of repetition numbers set / instructed by the RACH resource in question.

[0228] Alt 2-1-2-2)

[0229] One possible approach is to introduce additional parameters into higher layer signaling (e.g., SIB1) and divide the preamble index interval (i.e., the starting preamble index and / or the number of preamble indices) by repetition number.

[0230] A. The base station can set / instruct one or more repetition numbers based on higher layer signaling (e.g., SIB1). Characteristically, the repetition number may be set / instructed based on parameters for legacy RACH configuration and / or additional RACH configuration (e.g., RACH-commonconfig).

[0231] B. A base station can assign one RACH partitioning that corresponds to a feature combination containing the PRACH repetition feature (e.g., Msg. 1 Repetition R18) and / or the relevant feature.

[0232] If a repetition number is set / specified, a preamble interval for that repetition number may be set via existing parameters (e.g., startPreambleForThisPartition-r17, numberOfPreamblesPerSSB-ForThisPartition-r17).

[0233] If multiple repetition numbers are set / instructed, the following actions / settings may apply.

[0234] i. The preamble interval for the lowest (or highest) repetition number can be set via existing parameters (e.g., startPreambleForThisPartition-r17, numberOfPreamblesPerSSB-ForThisPartition-r17). The preamble intervals for the remaining repetition numbers can be set based on the following embodiments.

[0235] Alt 2-1-2-2-1)

[0236] For each remaining repetition number, a pair of additional parameters (e.g., additionalstartPreambleForThisPartition-r18, additionalnumberOfPreamblesPerSSB-ForThisPartition-r18) is set / instructed, and through these, the preamble interval for the next repetition number may be set.

[0237] In other words, if a total of three repetition numbers are specified (e.g., R={A,B,C}), the preamble interval for one repetition number (e.g.,A) can be set using existing parameters, as shown in Figure 14, and the preamble intervals for the remaining repetition numbers can be set by adding two pairs of additional parameters.

[0238] Alt 2-1-2-2-2)

[0239] To allocate the remaining repetitions, or to specify multiple starting preamble offsets, an offset from the starting index indicated by an existing parameter may be specified. In this case, the number of preambles can also be specified as an additional parameter and may be set / defined to reuse an existing parameter.

[0240] Alt 2-1-2-2-3)

[0241] Without any additional parameters, the preamble interval for the previous repetition number can be set / defined so that the interval for the next repetition number begins immediately after the interval for the previous repetition number ends. In this case, the number of preambles can also be specified separately, and the existing parameters can be reused.

[0242] 1. In this case, a parameter representing the existing number of preambles may be defined to be used as the offset of the starting index.

[0243] Additionally, the number of preambles can be specified as an additional parameter, which may be set to reuse existing parameters.

[0244] In the above method, the terminal can expect that each preamble section corresponding to a different repetition number will not overlap with each other.

[0245] Alt 2-2)

[0246] One possible approach is to set the parameters for feature combination to be different for each repetition number.

[0247] As an example, as shown in Figure 15, the parameters for a feature combination can be defined to include repetition number values ​​(e.g., msg. 1 Repetition A, msg. 1 Repetition B, msg. 1 Repetition C).

[0248] Either the base station does not need to specify repetition number values ​​separately within the RACH Configuration, or multiple parameters should be set for the feature combination.

[0249] As an example, as shown in Table 9, different features can be introduced for each repetition number (e.g., R = A, B, C) (in this case, A, B, and C can be one of 2, 4, or 8).

[0250] [Table 9]

[0251] As described above, the base station can instruct the terminal to perform PRACH resource partitioning corresponding to each repetition number through the feature combination method, while setting the repetition numbers to different features.

[0252] Characteristically, a terminal can expect that within a specific additional RACH configuration, RACH partitioning consisting of feature combinations between multiple PRACH features with different repetition numbers will not be configured. If such a configuration occurs, the terminal can determine that it is an invalid configuration.

[0253] The above operation is applicable to all legacy RACH configurations and / or Additional RACH configurations.

[0254] [Method 3]

[0255] One possible approach is to use TDM to separate and allocate multiple PRACH repetition resources with different repetition counts to the same RACH configuration.

[0256] A. The base station can set / instruct the repetition number as follows: The repetition number may be set / instructed based on RACH-commonconfig or FeatureCombinationPreambles. For example, a parameter (e.g., RACH-commonconfig) within each additional RACH configuration (e.g., AdditionalRACH-Config-r17) may include a repetition number. For example, RACH partitioning (e.g., FeatureCombinationPreambles) within RACH-commonconfig may include a repetition number.

[0257] i. As a specific example, the repetition number instructed by the base station can be multiple numbers from {1, 2, 4, 8}.

[0258] ii. As another example, the repetition number instructed by the base station can be one or more of {2, 4, 8}. That is, it can be assumed that single transmission is always set.

[0259] B. The number of ROmask parameters can be set / instructed based on higher layer signaling (e.g., SIB1) for each repetition number instructed by the base station.

[0260] i. RO mask parameters, set for each different repetition number, can be parameters with a size equal to the number of TDMed ROs corresponding to the SSB-to-RO mapping period. These RO mask parameters can be defined to represent / indicate TDMed ROs corresponding to a specific repetition number as a bitmap.

[0261] As a specific example, if the total number of ROs located at different time instances within a specific interval (e.g., PRACHconfiguration period, association (pattern) period, etc.) is N, the size of the RO mask parameter can be set to N bits.

[0262] As another example, if the total number of ROs associated with the same SSB within a specific interval (e.g., PRACH configuration period, association (pattern) period, etc.) that are located at different time instances is M, then the size of the RO mask parameter may be set to M bits.

[0263] 2. If K repetition numbers (2 or more) are set / instructed for the applicable RACH configuration, a total of K ROmask parameters (2 or more) will be instructed, and each RO mask parameter may be instructed to be different for each repetition number.

[0264] 3. The terminal can determine which RO is to be used for PRACH repetitive transmission (or is included in an RO group for repetitive transmission) according to the N-bit (or M-bit) bitmap, and can use it to perform repetitive transmission.

[0265] 4. In this case, the terminals can expect that the RO locations indicated by the RO mask parameters, which are set for different repetition numbers, will be assigned so as not to overlap in the time domain.

[0266] ii. Characteristically, no separate RO mask parameter is introduced for repetition number 1, and the remaining ROs can be set / defined as ROs for single PRACH transmission without specifying RO mask parameters for 2 or more repetition numbers.

[0267] iii. The base station may configure / instruct the terminal to configure / configure candidate ROs based on RO mask parameters for each repetition number configured / instructed by the base station. The terminal can then select ROs from the candidate ROs that correspond to the UL beam that the terminal intends to transmit via SSB-to-RO mapping (i.e., ROs associated with the SSB index selected by the terminal) by repetition number and execute the RACH procedure (or configure an RO group).

[0268] C. On the other hand, it may be assumed that a specific preamble index interval is set / defined via RACH partitioning to a PRACHrepetition feature (e.g., Msg.1 Repetition R18) and / or a feature combination that includes the relevant feature. The relevant RACH partitioning can only be applied to ROs set / indicated via RO mask parameters for two or more repetition numbers.

[0269] i. That is, ROs not selected through the RO mask parameter for two or more repetition numbers may be defined as ignoring the RACH partitioning set / defined in the PRACH repetition feature (e.g., Msg.1 Repetition R18) and / or the feature combination containing the relevant feature, and the relevant preamble index interval may be used by the terminal for single RACH transmission purposes.

[0270] The proposed method can be configured / applied to other UL signals / channels such as MSG3 PUSCH, MSGA Preamble / PUSCH, or PUSCH / PUCCH. Characteristically, the proposed terminal / base station operation for PRACH repetition can also be configured / applied to other newly introduced features (e.g., the Msg.4 HARQ ACK PUCCH repetition transmission feature). For example, a feature for PUCCH repetition (e.g., pucch-Repetitions-r18) can be configured / applied in place of the proposed feature for PRACH repetition, and the feature for PUCCH repetition can also be used in the proposed combination method and in methods that the terminal does not expect. Furthermore, if terminal / base station operations for PRACH repetition and / or PUCCH repetition are supported simultaneously, the proposed method can be configured / applied to both channels.

[0271] Furthermore, the example of the proposed scheme described above can also be considered a type of proposed scheme, as it may be included as one of the implementation methods of this specification. Moreover, while the proposed scheme described above can be implemented independently, it may also be implemented in the form of a combination (or merger) of some of the proposed methods. The rules may be defined so that the base station informs the terminal of the applicability of the method (or information regarding the rules of the method) via a predefined signal (e.g., a physical layer signal or a higher layer signal). The higher layer may include one or more functional layers such as MAC, RLC, PDCP, RRC, and SDAP.

[0272] The methods, embodiments, or descriptions for implementing the methods proposed herein may be applied separately, or one or more methods (or embodiments or descriptions) may be applied in combination.

[0273] In terms of practical aspects, the operations of the base station / terminal according to the foregoing embodiments (e.g., operations based on at least one of Methods 1 to 3) can be processed by the device in FIG. 18 described below (e.g., processors 110 and 210 in FIG. 18).

[0274] Also, the operations of the base station / terminal according to the foregoing embodiments (e.g., operations based on at least one of Methods 1 to 3) may be stored in a memory (e.g., 140 and 240 in FIG. 18) in the form of instruction words / programs (e.g., instruction, executable code) for driving at least one processor (e.g., 110 and 210 in FIG. 18).

[0275] Hereinafter, the foregoing embodiments will be specifically described with reference to FIGS. 16 and 17 from the perspective of the operations of the terminal and the base station. The methods described below are only divided for the convenience of explanation, and it is of course possible that some configurations of any one method are replaced by or combined with some configurations of other methods and applied.

[0276] FIG. 16 is a flowchart for explaining a method executed by a terminal according to an embodiment of the present specification.

[0277] Referring to FIG. 16, the method executed by a terminal according to an embodiment of the present specification includes a RACH setting reception step (S1610) and a Random Access Preamble transmission step (S1620).

[0278] In S1610, the terminal receives a random access channel (RACH) setting from the base station.

[0279] In S1620, the terminal transmits a Random Access Preamble based on the repetition number related to the feature combination to the base station.

[0280] As an example, the random access preamble may be transmitted based on Table 1. Specifically, the transmission of the random access preamble based on the number of repetitions can mean that the random access preamble transmission based on one RO (RACHoccasion) is performed multiple times. Therefore, the repeated transmission of the random access preamble can mean PRACH transmission based on multiple ROs. In this case, multiple ROs may be associated with the same Synchronization Signal / Physical Broadcast Channel Block Index (SS / PBCH Block Index).

[0281] In one embodiment, the RACH setting (e.g., RACH-ConfigCommon) may include a plurality of preamble settings. Each of the plurality of preamble settings may be associated with a single feature combination. The number of iterations may be one of a plurality of iterations based on the plurality of preamble settings. This embodiment may be based on Alt 2-1-1) of Method 2.

[0282] As an example, the RACH setting may include a RACH setting based on a Bandwidth Part (BWP) - Uplink Common setting. The BWP-Uplink Common setting may be based on the BWP-Uplink Common setting described in Figure 4 and Table 7. Specifically, the RACH setting may include i) RACH setting I within the BWP-Uplink Common setting and ii) RACH settings based on each additional RACH setting within the BWP-Uplink Common setting. Each additional RACH setting may be based on AdditionalRACH-Config-r17 in Figure 4 and Table 7.

[0283] Each preamble setting based on the RACH setting (e.g., FeatureCombinationPreambles) may include information about a set of preambles. In the Bandwidth Portion (BWP), there may be at most one set of preambles associated with each of the multiple iteration counts. That is, the multiple iteration counts may be based on different values. The BWP may be configured based on the BWP uplink common setting.

[0284] For example, the number of repetitions can be associated with a shared random access channel opportunity (RACH Occasion, RO).

[0285] For example, the number of repetitions may be 2, 4, or 8.

[0286] As an example, one or more features may be specified based on the feature combination. The one or more features may include MSG1 repetitions. The number of repetitions may be set based on a preamble setting that includes a feature combination associated with the MSG1 repetitions. More specifically, the number of repetitions may be set based on a preamble setting that includes a feature combination associated with the MSG1 repetitions, among the preamble settings based on the RACH setting.

[0287] In one embodiment, the number of iterations may be determined based on the Reference Signal Received Power (RSRP) among the multiple number of iterations. For example, the number of iterations applicable to a random access procedure may be determined based on the fact that the RSRP is lower than an RSRP threshold. As a specific example, the RSRP threshold may be defined / set for each number of iterations. Based on the fact that the RSRP is lower than the RSRP threshold for a particular number of iterations (e.g., 2, 4, or 8), the number of iterations may be determined as the particular number of iterations among the multiple number of iterations (e.g., 2, 4, 8).

[0288] The operations based on S1610 to S1620 described above can be realized by the device shown in Figure 18. For example, terminal 200 can control one or more transceivers 230 and / or one or more memories 240 to perform the operations based on S1610 to S1620.

[0289] The above-mentioned embodiment will now be described in detail from the perspective of the base station's operation.

[0290] The S1710-S1720 described later correspond to the S1610-S1620 explained in Figure 16. Considering this correspondence, redundant explanations are omitted. That is, the specific explanations of base station operations described later can be replaced by the corresponding explanations / embodiments in Figure 16. For example, the explanations / embodiments of S1610-S1620 in Figure 16 can be further applied to the base station operations of S1710-S1720 described later.

[0291] Figure 17 is a flowchart illustrating a method performed by a base station according to other embodiments of this specification.

[0292] Referring to Figure 17, a method performed by a base station according to other embodiments of this specification includes a RACH configuration transmission step (S1710) and a random access preamble reception step (S1720).

[0293] In S1710, the base station transmits a random access channel (RACH) configuration to the terminal.

[0294] In S1720, the base station receives a random access preamble from the terminal based on the repetition number related to the feature combination.

[0295] The operations based on S1710 to S1720 described above can be realized by the device in FIG. 18. For example, the base station 100 can control one or more transceivers 130 and / or one or more memories 140 to execute the operations based on S1710 to S1720.

[0296] The operations / terms based on the above-described embodiments are described assuming a 5G system. However, this is for the convenience of explanation and is not intended to limit the technical problems to be solved and the scope of application of the problem-solving means by this specification to a specific system. That is, the technical problems / issues / problems mentioned in this specification can similarly exist in other systems (for example, 6G systems). It is clear that the embodiments of this specification can be extended and applied to solve the same problems existing in the other systems. Therefore, for the extended application of the embodiments of this specification to other systems, the terms defined / described based on the 5G system can be replaced / changed with the terms defined in the other systems (or generalized terms not specific to one system).

[0297] Hereinafter, the device to which the embodiments of this specification can be applied (the device that realizes the method / operation according to the embodiments of this specification) will be described with reference to FIG. 18.

[0298] Figure 18 shows the configurations of the first and second apparatus according to embodiments of this specification.

[0299] The first device 100 may include a processor 110, an antenna unit 120, a transceiver 130, and a memory 140.

[0300] The processor 110 performs baseband-related signal processing and may include a higher-level processing unit 111 and a physical-level processing unit 115. The higher-level processing unit 111 can process MAC layer, RRC layer, or higher-level layer operations. The physical-level processing unit 115 can process PHY layer operations. For example, if the first device 100 is a base station device in base station-terminal communication, the physical-level processing unit 115 can perform uplink received signal processing, downlink transmitted signal processing, etc. For example, if the first device 100 is a first terminal device in terminal-terminal communication, the physical-level processing unit 115 can perform downlink received signal processing, uplink transmitted signal processing, sidelink transmitted signal processing, etc. In addition to performing baseband-related signal processing, the processor 110 can also control the overall operation of the first device 100.

[0301] The antenna unit 120 may include one or more physical antennas, and if it includes multiple antennas, it can support MIMO transmission and reception. The transceiver 130 may include an RF (Radio Frequency) transmitter and an RF receiver. The memory 140 can store information processed by the processor 110, as well as software, an operating system, applications, etc., related to the operation of the first device 100, and may also include components such as buffers.

[0302] The processor 110 of the first device 100 can be configured to implement the operation of the base station in base station-terminal communication (or the operation of the first terminal device in terminal-terminal communication) in the embodiments described herein.

[0303] The second device 200 may include a processor 210, an antenna unit 220, a transceiver 230, and a memory 240.

[0304] The processor 210 performs baseband-related signal processing and may include a higher-level processing unit 211 and a physical-level processing unit 215. The higher-level processing unit 211 can process MAC layer, RRC layer, or higher-level layer operations. The physical-level processing unit 215 can process PHY layer operations. For example, if the second device 200 is a terminal device in base station-terminal communication, the physical-level processing unit 215 can perform downlink received signal processing, uplink transmitted signal processing, etc. For example, if the second device 200 is a second terminal device in terminal-to-terminal communication, the physical-level processing unit 215 can perform downlink received signal processing, uplink transmitted signal processing, sidelink received signal processing, etc. In addition to performing baseband-related signal processing, the processor 210 can also control the overall operation of the second device 200.

[0305] The antenna unit 220 may include one or more physical antennas, and if it includes multiple antennas, it can support MIMO transmission and reception. The transceiver 230 may include an RF transmitter and an RF receiver. The memory 240 can store information processed by the processor 210, and software, an operating system, applications, etc., related to the operation of the second device 200, and may also include components such as buffers.

[0306] The processor 210 of the second device 200 can be configured to implement the operation of a terminal in base station-terminal communication (or the operation of a second terminal device in terminal-terminal communication) in the embodiments described herein.

[0307] In the operation of the first device 100 and the second device 200, the matters described in the examples of this disclosure regarding the base station and terminal in base station-terminal communication (or the first terminal and second terminal in terminal-terminal communication) can be applied in the same manner, and redundant explanations will be omitted.

[0308] Here, the wireless communication technologies implemented in the devices 100 and 200 of this 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 is an example of LPWAN (Low Power Wide Area Network) technology and can be implemented using standards such as LTE Cat NB1 and / or LTE Cat NB2, and is not limited to the aforementioned names.

[0309] Additionally or alternatively, the wireless communication technology implemented in the devices 100, 200 of this disclosure can communicate based on LTE-M technology. For example, LTE-M technology is an example of LPWAN technology and is known by various names such as eMTC (enhanced Machine Type Communication). For example, LTE-M technology can be implemented using 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 names mentioned above.

[0310] Additionally or alternatively, the wireless communication technologies implemented in the devices 100, 200 of this disclosure may include, but are not limited to, at least one of ZigBee, Bluetooth (registered trademark), and Low Power Wide Area Network (LPWAN) technologies, with regard to low-power communication. For example, ZigBee technology can generate personal area networks (PANs) related to small / low-power digital communication based on various standards such as IEEE 802.15.4, and can be referred to by a variety of names.

[0311] [Claims when filing an international application] [Claim 1] A method performed by the terminal (user equipment: UE), Steps include receiving the Random Access Channel (RACH) configuration, The process includes the step of transmitting a Random Access Preamble based on a repetition number associated with a combination of functions, The RACH setting includes multiple preamble settings, Each of the aforementioned preamble settings is associated with one feature combination. A method characterized in that the number of repetitions is one of a plurality of repetitions based on the plurality of preamble settings. [Claim 2] The method according to claim 1, characterized in that the number of repetitions is determined based on the Reference Signal Received Power (RSRP) among the plurality of repetitions. [Claim 3] The method according to claim 1, characterized in that the RACH setting includes a RACH setting based on a Bandwidth Part (BWP)-uplink common setting. [Claim 4] The RACH setting mentioned above is i) RACH setting in the BWP uplink common setting, and ii) The method according to claim 3, characterized in that it includes a RACH setting based on each additional RACH (Additional RACH) setting within the BWP uplink common setting. [Claim 5] Each preamble setting based on the aforementioned RACH setting includes information about the set of preambles, The method according to claim 4, characterized in that in the bandwidth portion (BWP), there is at most one set of preambles associated with each of the plurality of iteration counts. [Claim 6] The method according to claim 5, characterized in that the plurality of repetition counts are based on mutually different values. [Claim 7] Based on the aforementioned feature combination, one or more features are indicated. The method according to claim 1, characterized in that one or more of the functions include MSG1 repetitions. [Claim 8] The method according to claim 7, characterized in that the plurality of repetition counts are set based on a preamble setting that includes a feature combination associated with the MSG1 repetitions. [Claim 9] The method according to claim 8, characterized in that the plurality of iterations are related to a shared random access channel opportunity (RACH Occasion, RO). [Claim 10] The method according to claim 1, characterized in that the number of repetitions is 2, 4, or 8. [Claim 11] It is a terminal (user equipment: UE), One or more transceivers and One or more processors, The system comprises one or more memories connected to one or more processors for storing instructions, A terminal characterized in that, based on the fact that the instructions are performed by the one or more processors, the one or more processors are configured to perform all the steps of the method according to any one of claims 1 to 10. [Claim 12] A device (divice), One or more memory devices, The system comprises one or more memory units and one or more processors functionally connected to them, The apparatus is characterized in that the one or more memory stores instructions that, based on being executed by the 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 10. [Claim 13] One or more non-transitory computer-readable media for storing instructions, One or more non-transitory computer-readable media, characterized in that the instructions, which can be executed by one or more processors, are configured to cause the one or more processors to perform all the steps of the method according to any one of claims 1 to 10. [Claim 14] A method performed by a base station, The process includes a step of transmitting a Random Access Channel (RACH) configuration and a step of receiving a Random Access Preamble based on a repetition number related to a feature combination. The RACH setting includes multiple preamble settings, Each of the aforementioned preamble settings is associated with one feature combination. A method characterized in that the number of repetitions is one of a plurality of repetitions based on the plurality of preamble settings. [Claim 15] It is a base station, One or more transceivers, One or more processors, The system comprises one or more memories connected to one or more processors for storing instructions, A base station characterized in that, based on the fact that the instructions are performed by the one or more processors, the one or more processors are configured to perform all the steps of the method according to claim 14.

Claims

1. A method performed by a terminal (user equipment: UE), The steps include receiving the Random Access Channel (RACH) configuration, The process includes the step of transmitting a Random Access Preamble based on a repetition number associated with a combination of functions, The RACH setting includes multiple preamble settings, Each of the aforementioned preamble settings is associated with a feature combination. A method characterized in that the number of repetitions is one of a plurality of repetitions based on the plurality of preamble settings.

2. The method according to claim 1, characterized in that the number of repetitions is determined based on the Reference Signal Received Power (RSRP) among the plurality of repetitions.

3. The method according to claim 1, characterized in that the RACH setting includes a RACH setting based on a Bandwidth Part (BWP) - Uplink Common setting.

4. The aforementioned RACH setting is, i) RACH setting in the BWP uplink common setting, and ii) The method according to claim 3, characterized in that it includes a RACH setting based on each additional RACH (Additional RACH) setting in the BWP uplink common setting.

5. Each preamble setting based on the RACH setting includes information about the set of preambles, The method according to claim 4, characterized in that in the bandwidth portion (BWP), there is at most one set of preambles associated with each of the plurality of repetition counts.

6. The method according to claim 5, characterized in that the plurality of repetition counts are based on mutually different values.

7. Based on the aforementioned feature combination, one or more features are specified. The method according to claim 1, characterized in that one or more of the functions include MSG1 repetitions.

8. The method according to claim 7, characterized in that the plurality of iteration counts are set based on a preamble setting that includes a feature combination associated with the MSG1 repetitions.

9. The method according to claim 8, characterized in that the plurality of iterations are related to a shared random access channel opportunity (RACH Occasion, RO).

10. The method according to claim 1, characterized in that the number of repetitions is 2, 4, or 8.

11. A terminal (user equipment: UE), One or more transceivers and One or more processors, The system comprises one or more memories connected to one or more processors for storing instructions, A terminal characterized in that, based on the fact that the instructions are executed by the one or more processors, the one or more processors are configured to perform all the steps of the method according to any one of claims 1 to 10.

12. A device (device), One or more memory devices, The system comprises one or more memory units and one or more processors functionally connected to them, The apparatus is characterized in that the one or more memory stores instructions that, on the basis that they are to be executed by the one or more processors, cause the one or more processors to perform all the steps of the method according to any one of claims 1 to 10.

13. One or more non-transitory computer-readable media for storing instructions, One or more non-transitory computer-readable media, characterized in that the instructions, which can be executed by one or more processors, are configured to cause the one or more processors to perform all the steps of the method according to any one of claims 1 to 10.

14. A method performed by a base station, The process includes the steps of transmitting a Random Access Channel (RACH) configuration and receiving a Random Access Preamble based on a repetition number related to a feature combination, The RACH setting includes multiple preamble settings, Each of the aforementioned multiple preamble settings is associated with one feature combination. A method characterized in that the number of repetitions is one of a plurality of repetitions based on the plurality of preamble settings.

15. It is a base station, One or more transceivers, One or more processors, The system comprises one or more memories connected to one or more processors for storing instructions, A base station characterized in that, based on the fact that the instructions are executed by the one or more processors, the one or more processors are configured to perform all the steps of the method according to claim 14.

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