Method and apparatus for uplink transmission and reception in wireless communication system

Abstract

Methods and apparatus for uplink transmission and reception in a wireless communication system are disclosed. A method performed by a wireless communication system according to an embodiment of the present disclosure may comprise the steps of: receiving first configuration information related to physical random access channel (PRACH) preamble repeat transmission from a base station; and performing a first PRACH preamble repeat transmission in a plurality of first random access channel opportunities (ROs) based on the first configuration information, in which a power of the first PRACH preamble repeat transmission performed across the plurality of first ROs is based on a first reference signal (RS) for acquiring a path loss value, and a transmission power ramp is not applied within the plurality of first ROs.

Description

Technical Field

[0001] The present disclosure relates to a wireless communication system, and more particularly, to a method and apparatus for performing uplink transmission and reception in a wireless communication system. Background Art

[0002] A mobile communication system has been developed to provide voice services while ensuring user mobility. However, the mobile communication system has been extended to data services as well as voice services, and currently, the explosive growth of services has led to resource shortages, and users have demanded faster services, thus requiring more advanced mobile communication systems.

[0003] The overall requirements of the next generation mobile communication system should be able to support the accommodation of explosive data services, a significant increase in the transmission rate per user, the accommodation of a significantly increased number of connected devices, very low end-to-end latency and high energy efficiency. To this end, a variety of technologies such as dual connectivity, massive multiple-input multiple-output (massive MIMO), in-band full-duplex, non-orthogonal multiple access (NOMA), ultra-wideband support, and device networking have been studied. Summary of the invention

[0004] Technical issues

[0005] A technical problem of the present disclosure is to provide a method and apparatus for performing uplink transmission and reception in a wireless communication system.

[0006] In addition, an additional technical problem of the present disclosure is to provide a method and apparatus for performing beam operation and power control for repeated transmission of a PRACH preamble code.

[0007] In addition, an additional technical problem of the present disclosure is to provide a method and apparatus for setting a reference signal for calculating a path loss during repeated transmission of a PRACH preamble.

[0008] The technical objectives to be achieved by the present disclosure are not limited to the above-mentioned technical objectives, and those skilled in the art can clearly understand other technical objectives not described herein through the following description.

[0009] Technical Solution

[0010] According to one embodiment of the present disclosure, a method performed by a user equipment (UE) in a wireless communication system may include: receiving first configuration information related to repeated transmission of a physical random access channel (PRACH) preamble code from a base station; and based on the first configuration information, performing repeated transmission of a first PRACH preamble code in multiple first ROs (random access channel opportunities), and the power of the repeated transmission of the first PRACH preamble code performed across the multiple first ROs may be based on a first reference signal (RS) for obtaining a path loss value, and transmission power ramping may not be applied within the multiple first ROs.

[0011] According to one embodiment of the present disclosure, a method performed by a base station in a wireless communication system may include: sending first configuration information related to repeated transmission of a physical random access channel (PRACH) preamble code to a user equipment (UE); and based on the first configuration information, performing repeated reception of a first PRACH preamble code in multiple first ROs (random access channel opportunities), and the power of the repeated transmission of the first PRACH preamble code performed across the multiple first ROs may be based on a first reference signal (RS) for obtaining a path loss value, and transmission power ramping may not be applied within the multiple first ROs.

[0012] Technical Effects

[0013] According to an embodiment of the present disclosure, a method and apparatus for performing uplink transmission and reception in a wireless communication system may be provided.

[0014] In addition, according to various embodiments of the present disclosure, a method and apparatus for performing beam operation and power control for repeated transmission of a PRACH preamble code may be provided.

[0015] In addition, according to various embodiments of the present disclosure, a method and apparatus for configuring a reference signal for calculating a path loss during repeated transmission of a PRACH preamble code may be provided.

[0016] In addition, according to various embodiments of the present disclosure, the transmission power may be set not to change when performing PRACH preamble code repetition transmission.

[0017] Effects achievable by the present disclosure are not limited to the above-described effects, and other effects not described herein may be clearly understood by those skilled in the art through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are included as a part of the detailed description for understanding the present disclosure, provide embodiments of the present disclosure and describe technical features of the present disclosure through the detailed description.

[0019] Figure 1 The structure of a wireless communication system to which the present disclosure can be applied is illustrated.

[0020] Figure 2 The frame structure in a wireless communication system to which the present disclosure can be applied is illustrated.

[0021] Figure 3 A resource grid in a wireless communication system to which the present disclosure can be applied is illustrated.

[0022] Figure 4 The physical resource blocks in a wireless communication system to which the present disclosure can be applied are illustrated.

[0023] Figure 5 The time slot structure in a wireless communication system to which the present disclosure can be applied is illustrated.

[0024] Figure 6 Physical channels used in a wireless communication system to which the present disclosure can be applied and a general signal transmission and reception method using the physical channels are illustrated.

[0025] Figure 7 An example of a wireless communication system supporting a license-free band applicable to the present disclosure is illustrated.

[0026] Figure 8 is a diagram illustrating uplink transmission and reception operations in a wireless communication system to which the present disclosure can be applied.

[0027] Fig. 9 Detailed description is a diagram for explaining an uplink transmission operation of a UE in a wireless communication system to which the present disclosure may be applied.

[0028] Fig.10 Detailed description is a diagram for describing an uplink reception operation of a base station in a wireless communication system to which the present disclosure may be applied.

[0029] Fig.11 2 is a diagram for describing an operation of a terminal selecting an RO for repeated transmission of a PRACH preamble according to an embodiment of the present disclosure.

[0030] Fig.12 It is a diagram for describing the signaling process of the network side and the UE according to an embodiment of the present disclosure.

[0031] Fig.13 is an exemplary block diagram of a wireless communication device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0032] Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description disclosed by the accompanying drawings is intended to describe exemplary embodiments of the present disclosure, rather than to represent the only embodiment in which the present disclosure can be implemented. The following detailed description includes specific details to provide a complete understanding of the present disclosure. However, those skilled in the relevant art know that the present disclosure can be implemented without these specific details.

[0033] In some cases, well-known structures and devices may be omitted, or may be shown in the form of a block diagram based on the core functions of each structure and device in order to prevent ambiguity in the concepts of the present disclosure.

[0034] In the present disclosure, when an element is referred to as being "connected", "combined" or "linked" to another element, it may include an indirect connection relationship between another element and a direct connection relationship. In addition, in the present disclosure, the term "comprising" or "having" specifies the presence of the mentioned features, steps, operations, components and / or elements, but does not exclude the presence or addition of one or more other features, stages, operations, components, elements and / or groups thereof.

[0035] In the present disclosure, terms such as "first", "second", etc. are only used to distinguish one element from another element and are not used to limit the elements, and unless otherwise specified, they do not limit the order or importance between elements, etc. Therefore, within the scope of the present disclosure, the first element in an embodiment may be referred to as the second element in another embodiment, and similarly, the second element in an embodiment may be referred to as the first element in another embodiment.

[0036] The terms used in this disclosure are intended to describe specific embodiments, rather than to limit the claims. As used in the description of the embodiments and the appended claims, the singular form is intended to include the plural form, unless the context clearly indicates otherwise. The term "and / or" used in this disclosure may refer to one of the related enumerated items, or mean that it refers to and includes any and all possible combinations of two or more of them. In addition, unless otherwise stated, the " / " between words in this disclosure has the same meaning as "and / or".

[0037] The present disclosure describes a wireless communication network or a wireless communication system, and operations performed in the wireless communication network may be performed in a process in which a device (e.g., a base station) controlling a corresponding wireless communication network controls the network and transmits or receives a signal, or may be performed in a process in which a terminal associated with the corresponding wireless network transmits or receives a signal between the network or the terminal.

[0038] In the present disclosure, sending or receiving a channel includes the meaning of sending or receiving information or signals through the corresponding channel. For example, sending a control channel means sending control information or control signals through the control channel. Similarly, sending a data channel means sending data information or data signals through the data channel.

[0039] In the following, downlink (DL) means communication from a base station to a terminal, and uplink (UL) means communication from a terminal to a base station. In the downlink, the transmitter may be part of a base station, and the receiver may be part of a terminal. In the uplink, the transmitter may be part of a terminal, and the receiver may be part of a base station. The base station may be expressed as a first communication device, and the terminal may be expressed as a second communication device. The base station (BS) may be replaced by terms such as a fixed station, a node B, an eNB (evolved node B), a gNB (next generation node B), a BTS (base station transceiver system), an access point (AP), a network (5G network), an AI (artificial intelligence) system / module, an RSU (roadside unit), a robot, a drone (UAV: unmanned aerial vehicle), an AR (augmented reality) device, a VR (virtual reality) device, and the like. In addition, the terminal can be fixed or mobile, and can be replaced by 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, RSU (roadside unit), robot, AI (artificial intelligence) module, drone (UAV: unmanned aerial vehicle), AR (augmented reality) device, VR (virtual reality) device, etc.

[0040] The following description can be used for various radio access systems, such as CDMA, FDMA, TDMA, OFDMA, SC-FDMA, etc. CDMA can be implemented by UTRA (Universal Terrestrial Radio Access) or CDMA2000. TDMA can be implemented by radio technologies such as GSM (Global System for Mobile Communications) / GPRS (General Packet Radio Service) / EDGE (Data Rate Enhanced GSM Evolution). OFDMA can be implemented by radio technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE802-20, E-UTRA (Evolved UTRA), etc. UTRA is part of UMTS (Universal Mobile Telecommunications System). 3GPP (3rd Generation Partnership Project) LTE (Long Term Evolution) is part of E-UMTS (Evolved UMTS) using E-UTRA, and LTE-A (Advanced) / LTE-Apro is an advanced version of 3GPP LTE. 3GPP NR (New Radio or New Radio Access Technology) is an advanced version of 3GPP LTE / LTE-A / LTE-A pro.

[0041] In order to make the description clearer, the description is based on the 3GPP communication system (e.g., LTE-A, NR), but the technical idea of ​​the present disclosure is not limited to this. LTE means the technology after 3GPP TS (Technical Specification) 36.xxx version 8. Specifically, the LTE technology in or after 3GPP TS 36.xxx version is called LTE-A, and the LTE technology in or after 3GPP TS 36.xxx version 13 is called LTE-A pro. 3GPP NR means the technology in or after TS 38.xxx version. LTE / NR can be referred to as a 3GPP system. "xxx" means the detailed number of the standard document. LTE / NR can generally be referred to as a 3GPP system. For the background technology, terms, abbreviations, etc. used to describe the present disclosure, reference can be made to the matters described in the standard documents disclosed before the present disclosure. For example, reference can be made to the following documents.

[0042] For 3GPP LTE, reference may be made to TS 36.211 (Physical Channels and Modulation), TS 36.212 (Multiplexing and Channel Coding), TS 36.213 (Physical Layer Procedures), TS 36.300 (Overall Description), and TS 36.331 (Radio Resource Control).

[0043] For 3GPP NR, you can refer to TS 38.211 (Physical channels and modulation), TS 38.212 (Multiplexing and channel coding), TS 38.213 (Physical layer procedures for control), TS 38.214 (Physical layer procedures for data), TS 38.300 (NR and NG-RAN (Next Generation Radio Access Network) overall description), and TS 38.331 (Radio Resource Control Protocol Specification).

[0044] Abbreviations of terms that may be used in the present disclosure are defined as follows.

[0045] -BM: Beam Management

[0046] -CQI: Channel Quality Indicator

[0047] -CRI: Channel State Information-Reference Signal Resource Indicator

[0048] -CSI: Channel State Information

[0049] -CSI-IM: Channel State Information-Interference Measurement

[0050] -CSI-RS: Channel State Information-Reference Signal

[0051] -DMRS: Demodulation Reference Signal

[0052] -FDM: Frequency Division Multiplexing

[0053] -FFT: Fast Fourier Transform

[0054] -IFDMA: Interleaved Frequency Division Multiple Access

[0055] -IFFT: Inverse Fast Fourier Transform

[0056] -L1-RSRP: Layer 1 reference signal received power

[0057] -L1-RSRQ: Layer 1 reference signal reception quality

[0058] -MAC: Media Access Control

[0059] -NZP: Non-Zero Power

[0060] -OFDM: Orthogonal Frequency Division Multiplexing

[0061] -PDCCH: Physical Downlink Control Channel

[0062] -PDSCH: Physical Downlink Shared Channel

[0063] -PMI: Precoding matrix indicator

[0064] -RE: Resource Element

[0065] -RI: Rank indicator

[0066] -RRC: Radio Resource Control

[0067] -RSSI: Received Signal Strength Indicator

[0068] -Rx: Receive

[0069] -QCL: Quasi-Co-located

[0070] -SINR: Signal to Interference and Noise Ratio

[0071] -SSB (or SS / PBCH block): synchronization signal block (including PSS (primary synchronization signal), SSS (secondary synchronization signal) and PBCH (physical broadcast channel))

[0072] -TDM: Time Division Multiplexing

[0073] -TRP: Transmit and Receive Point

[0074] -TRS: Tracking Reference Signal

[0075] -Tx: Send

[0076] -UE: User Equipment

[0077] -ZP: Zero Power

[0078] Overall system

[0079] As more communication devices require higher capacity, there has been a demand for improved mobile broadband communications compared to existing radio access technologies (RATs). In addition, large-scale MTC (machine type communication) that provides various services anytime and anywhere by connecting multiple devices and things is also one of the main issues to be considered in the next generation of communications. In addition, the design of communication systems considering services / terminals that are sensitive to reliability and latency is also discussed. Therefore, the introduction of next-generation RATs considering eMBB (enhanced mobile broadband communication), mMTC (massive MTC), URLLC (ultra-reliable low-latency communication), etc. is discussed, and for convenience, the corresponding technology is referred to as NR in this disclosure. NR is an expression representing an example of 5G RAT.

[0080] The new RAT system including NR uses an OFDM transmission method or a transmission method similar thereto. The new RAT system may follow OFDM parameters different from those of LTE. Alternatively, the new RAT system follows the parameters of the existing LTE / LTE-A as is, but may support a wider system bandwidth (e.g., 100 MHz). Alternatively, a cell may support multiple parameter sets. In other words, terminals operating according to different parameter sets may coexist in one cell.

[0081] A parameter set corresponds to one subcarrier spacing in the frequency domain. As the reference subcarrier spacing is scaled by an integer N, different parameter sets can be defined.

[0082] Figure 1 The structure of a wireless communication system to which the present disclosure can be applied is illustrated.

[0083] refer to Figure 1 , NG-RAN is configured with gNBs that provide the control plane (RRC) protocol side for the NG-RA (NG Radio Access) user plane (i.e., the new AS (Access Stratum) sublayer / PDCP (Packet Data Convergence Protocol) / RLC (Radio Link Control) / MAC / PHY) and the UE. The gNBs are interconnected through the Xn interface. In addition, the gNBs are connected to the NGC (Next Generation Core) through the NG interface. More specifically, the gNB is connected to the AMF (Access and Mobility Management Power) through the N2 interface, and to the UPF (User Plane Function) through the N3 interface.

[0084] Figure 2 The frame structure in a wireless communication system to which the present disclosure can be applied is illustrated.

[0085] The NR system may support multiple parameter sets. Here, the parameter set may be defined by subcarrier spacing and cyclic prefix (CP) overhead. Here, multiple subcarrier spacings may be derived by scaling the basic (reference) subcarrier spacing by an integer N (or, μ). In addition, although it is assumed that very low subcarrier spacings are not used in very high carrier frequencies, the parameter set used may be selected independently of the frequency band. In addition, various frame structures according to multiple parameter sets may be supported in the NR system.

[0086] In the following, OFDM parameter sets and frame structures that can be considered in the NR system are described. Multiple OFDM parameter sets supported in the NR system can be defined as shown in Table 1 below.

[0087] [Table 1]

[0088] μ <![CDATA[Δf=2 μ ·15[kHz]]]> CP 0 15 normal 1 30 normal 2 60 Normal, Extended 3 120 normal 4 240 normal

[0089] NR supports multiple parameter sets (or subcarrier spacing (SCS)) for supporting various 5G services. For example, when the SCS is 15kHz, the wide area of ​​the traditional cellular band is supported; and when the SCS is 30kHz / 60kHz, dense cities, lower latency and wider carrier bandwidth are supported; and when the SCS is 60kHz or higher, bandwidths exceeding 24.25GHz are supported to overcome phase noise. The NR band is defined as two types of frequency ranges (FR1, FR2). FR1 and FR2 can be configured as shown in Table 2 below. In addition, FR2 can mean millimeter wave (mmW).

[0090] [Table 2]

[0091] Frequency range specification Corresponding frequency range Subcarrier spacing FR1 410MHz–7125MHz 15,30,60kHz FR2 24250MHz–52600MHz 60,120,240kHz

[0092] Regarding the frame structure in the NR system, the sizes of various fields in the time domain are expressed as T c =1 / (Δf max ·N f ) is a multiple of the time unit. Here, Δf max is 480·10 3Hz, and N f is 4096. Downlink and uplink transmissions are configured (organized) to have duration T f =1 / Δf max N f / 100)·T c =10ms radio frame. Here, the radio frame is configured with 10 subframes, each of which has T sf =(Δf max N f / 1000)·T c =1 ms duration. In this case, there may be one frame set for the uplink and one frame set for the downlink. Furthermore, the transmission in the i-th uplink frame from the terminal should start T earlier than the corresponding downlink frame in the corresponding terminal. TA =(N TA +N TA,offset )T c For subcarrier spacing configuration μ, the time slots are arranged in n subframes. s μ ∈{0,...,N slot subframe,μ -1} and in the radio frame the number is incremented by n s,f μ ∈{0,...,N slot frame,μ -1}. A time slot is configured with N symb slot consecutive OFDM symbols, and Nsymb slot Determined according to CP. Time slot n in a subframe s μ The beginning of the OFDM symbol n in the same subframe s μ N symb slot All terminals may not perform transmission and reception at the same time, which means that all OFDM symbols of a downlink time slot or an uplink time slot may not be used. Table 3 shows the number of OFDM symbols per time slot in a normal CP (N symb slot ), the number of time slots per radio frame (N slot frame,μ ) and the number of time slots per subframe (N slot subframe,μ ), and Table 4 represents the number of OFDM symbols per slot, the number of slots per radio frame, and the number of slots per subframe in the extended CP.

[0093] [Table 3]

[0094] μ <![CDATA[N symb slot ]]> <![CDATA[N slot frame,μ ]]> <![CDATA[N slot subframe,μ ]]> 0 14 10 1 1 14 20 2 2 14 40 4 3 14 80 8 4 14 160 16

[0095] [Table 4]

[0096] μ <![CDATA[N symb slot ]]> <![CDATA[N slot frame,μ ]]> <![CDATA[N slot subframe,μ ]]> 2 12 40 4

[0097] Figure 2 is an example of μ=2 (SCS is 60kHz), see Table 3, 1 subframe can include 4 time slots. Figure 2 1 subframe = {1,2,4} shown in is an example, and the number of time slots that can be included in 1 subframe is defined in Table 3 or Table 4. In addition, a micro-time slot may include 2, 4 or 7 symbols or more or less symbols. Regarding the physical resources in the NR system, antenna ports, resource grids, resource elements, resource blocks, carrier parts, etc. can be considered. In the following, the physical resources that can be considered in the NR system will be described in detail. First, with respect to antenna ports, antenna ports are defined so that the channel carrying the symbols in the antenna port can be inferred from the channel carrying other symbols in the same antenna port. When the large-scale properties of the channel on which the symbols in one antenna port are carried can be inferred from the channel carrying the symbols of another antenna port, it can be said that the two antenna ports are in a QC / QCL (quasi-colocated or quasi-colocated) relationship.

[0098] In this case, the large-scale attribute includes at least one of delay spread, Doppler spread, frequency shift, average received power, and received timing.

[0099] Figure 3 A resource grid in a wireless communication system to which the present disclosure can be applied is illustrated.

[0100] refer to Figure 3 , exemplarily describing a resource grid configuration with N in the frequency domain RB μ N sc RB subcarriers, and one subframe is configured with 14·2 μ OFDM symbols, but not limited to this. In the NR system, the transmitted signal consists of 2 μ N symb (μ) OFDM symbols and N RB μ N sc RB Here, N RB μ ≤N RB max,μ . N RB max,μ represents the maximum transmission bandwidth, which may differ between uplink and downlink and between parameter sets. In this case, one resource grid can be configured for each μ and antenna port p. Each element of the resource grid for μ and antenna port p is called a resource element and is uniquely identified by an index pair (k, l'). Here, k = 0, ..., N RB μ N sc RB -1 is the index in the frequency domain, and l'=0,...,2 μ N symb (μ) -1 refers to the symbol position in the subframe. When referencing a resource element in a slot, an index pair (k, l) is used. Here, l = 0, ..., N symb μ -1. The resource element (k, l') for μ and antenna port p corresponds to the complex value a k,l' (p,μ) When there is no risk of aliasing or when no specific antenna port or parameter set is specified, the indices p and μ may be dropped and the complex value may be ak,l'(p) or ak,l'. In addition, a resource block (RB) is defined as N in the frequency domain. sc RB =12 consecutive subcarriers.

[0101] Point A serves as a common reference point for the resource block grid and is obtained as follows.

[0102] -OffsetToPointA for the primary cell (PCell) downlink represents the frequency offset between point A and the lowest subcarrier of the lowest resource block overlapping the SS / PBCH block used by the terminal for initial cell selection. Assuming a subcarrier spacing of 15kHz for FR1 and a subcarrier spacing of 60kHz for FR2, it is expressed in resource blocks.

[0103] -absoluteFrequencyPointA represents the frequency position of point A, expressed in ARFCN (Absolute Radio Frequency Channel Number). For subcarrier spacing configuration μ, common resource blocks are numbered from 0 upwards in the frequency domain. The center of subcarrier 0 of common resource block 0 for subcarrier spacing configuration μ is the same as "point A". Common resource block number n for subcarrier spacing configuration μ in the frequency domain CRB μ The relationship between and resource element (k, l) is given as follows in Equation 1.

[0104] [Formula 1]

[0105]

[0106] In Equation 1, k is defined relative to point A, so that k=0 corresponds to a subcarrier centered at point A. Physical resource blocks are spaced from 0 to N in a bandwidth part (BWP). BWP,i size,μ -1 numbering and i is the number of the BWP. Physical resource block n in BWP i PRB and public resource block n CRB The relationship between is given by the following formula 2.

[0107] [Formula 2]

[0108]

[0109] is the common resource block where the BWP starts relative to common resource block 0.

[0110] Figure 4 The present invention illustrates a physical resource block in a wireless communication system to which the present disclosure can be applied. Figure 5 The time slot structure in a wireless communication system to which the present disclosure can be applied is illustrated.

[0111] refer to Figure 4 and Figure 5 , a time slot includes multiple symbols in the time domain. For example, for a normal CP, 1 time slot includes 7 symbols, but for an extended CP, 1 time slot includes 6 symbols

[0112] A carrier includes multiple subcarriers in the frequency domain. An RB (resource block) is defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. A BWP (bandwidth part) is defined as multiple consecutive (physical) resource blocks in the frequency domain and may correspond to a parameter set (e.g., SCS, CP length, etc.). A carrier may include up to N (e.g., 5) BWPs. Data communication may be performed through an activated BWP, and only one BWP may be activated for a terminal. In a resource grid, each element is called a resource element (RE) and may map a complex symbol.

[0113] In the NR system, each component carrier (CC) can support up to 400MHz. If a terminal operating in such a wideband CC always operates to turn on the radio frequency (FR) chip for the entire CC, the terminal battery consumption may increase. Alternatively, when considering multiple application scenarios operating in a wideband CC (e.g., eMBB, URLLC, Mmtc, V2X, etc.), different parameter sets (e.g., subcarrier spacing, etc.) can be supported in each frequency band in the corresponding CC. Alternatively, each terminal may have different capabilities for the maximum bandwidth. Taking this into account, the base station can instruct the terminal to operate only in part of the bandwidth instead of the full bandwidth of the wideband CC, and for convenience, the corresponding partial bandwidth is defined as a bandwidth part (BWP). BWP can be configured with continuous RBs on the frequency axis and can correspond to a parameter set (e.g., subcarrier spacing, CP length, slot / microslot duration).

[0114] At the same time, even in one CC configured to the terminal, the base station can configure multiple BWPs. For example, a BWP occupying a relatively small frequency domain can be configured in the PDCCH monitoring time slot, and the PDSCH indicated by the PDCCH can be scheduled in a larger BWP. Alternatively, when the UE is congested in a specific BWP, other BWPs can be configured for some terminals for load balancing. Alternatively, considering the frequency domain inter-cell interference elimination between adjacent cells, etc., some full-bandwidth intermediate spectrums can be excluded, and BWPs on two edges can be configured in the same time slot. In other words, the base station can configure at least one DL / UL BWP to a terminal associated with a broadband CC. The base station can activate at least one DL / UL BWP in the configured DL / UL BWP at a specific time (through L1 signaling or MAC CE (control element) or RRC signaling, etc.). In addition, the base station can indicate switching to other configured DL / UL BWPs (through L1 signaling or MAC CE or RRC signaling, etc.).

[0115] Alternatively, based on a timer, when the timer value expires, a switch may be made to a determined DL / UL BWP. Here, the activated DL / UL BWP is defined as the active DL / UL BWP. However, before the terminal performs an initial access procedure or establishes an RRC connection, the configuration on the DL / UL BWP may not be received, so the DL / UL BWP assumed by the terminal in these cases is defined as the initial active DL / UL BWP.

[0116] Figure 6 Physical channels used in a wireless communication system to which the present disclosure can be applied and a general signal transmission and reception method using the physical channels are illustrated.

[0117] In a wireless communication system, a terminal receives information from a base station through a downlink and transmits information to the base station through an uplink. The information sent and received by the base station and the terminal includes data and various control information, and there are various physical channels according to the type / purpose of the information they send and receive.

[0118] When the terminal is turned on or newly enters a cell, it performs an initial cell search including synchronization with a base station (S601). For the initial cell search, the terminal can synchronize with the base station by receiving a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) from the base station, and obtain information such as a cell identifier (ID). Then, the terminal can obtain broadcast information in the cell by receiving a physical broadcast channel (PBCH) from the base station. At the same time, the terminal can check the downlink channel status by receiving a downlink reference signal (DL RS) in the initial cell search phase.

[0119] The terminal that has completed the initial cell search may obtain more detailed system information by receiving a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) according to information carried in the PDCCH (S602).

[0120] At the same time, when the terminal accesses the base station for the first time or there are no radio resources for signal transmission, it can perform a random access (RACH) process (S603 to S606) on the base station. For the random access process, the terminal can send a specific sequence as a preamble through a physical random access channel (PRACH) (S603 and S605), and can receive a response message to the preamble through a PDCCH and a corresponding PDSCH (S604 and S606). The contention-based RACH can additionally perform a contention resolution process.

[0121] The terminal that subsequently performs the above process may perform PDCCH / PDSCH reception (S607) and PUSCH (Physical Uplink Shared Channel) / PUCCH (Physical Uplink Control Channel) transmission (S608) as a general uplink / downlink signal transmission process. Specifically, the terminal receives downlink control information (DCI) through PDCCH. Here, DCI includes control information such as resource allocation information for the terminal, and the format varies according to its purpose of use.

[0122] At the same time, the control information sent by the terminal to the base station through the uplink or received by the terminal from the base station includes downlink / uplink ACK / NACK (acknowledgement / non-acknowledgement) signal, CQI (channel instruction indicator), PMI (precoding matrix indicator), RI (rank indicator), etc. For the 3GPP LTE system, the terminal can send the above-mentioned CQI / PMI / RI and other control information through PUSCH and / or PUCCH.

[0123] Table 5 shows an example of the DCI format in the NR system.

[0124] [Table 5]

[0125]

[0126] Referring to Table 5, DCI formats 0_0, 0_1 and 0_2 may include resource information (e.g., UL / SUL (supplementary UL), frequency resource allocation, time resource allocation, hopping, etc.), information related to transport blocks (TBs) (e.g., MCS (modulation coding and scheme), NDI (new data indicator), RV (redundancy version)), etc.), information related to HARQ (hybrid-automatic repeat and request) (e.g., process number, DAI (downlink assignment index), PDSCH-HARQ feedback timing, etc.), information related to multiple antennas (e.g., DMRS sequence initialization information, antenna port, CSI request, etc.), power control information related to PUSCH scheduling (e.g., PUSCH power control, etc.), and the control information included in each DCI format may be predefined.

[0127] DCI format 0_0 is used to schedule PUSCH in one cell. Information included in DCI format 0_0 is CRC (Cyclic Redundancy Check) scrambled by C-RNTI (Cell Radio Network Temporary Identifier) ​​or CS-RNTI (Configured Scheduling RNTI) or MCS-C-RNTI (Modulation Coding Scheme Cell RNTI) and transmitted.

[0128] DCI format 0_1 ​​is used to indicate the scheduling of one or more PUSCHs or to configure grant (CG) downlink feedback information to a terminal in a cell. The information included in DCI format 0_1 ​​is scrambled and transmitted by C-RNTI or CS-RNTI or SP-CSI-RNTI (semi-persistent CSI RNTI) or MCS-C-RNTI.

[0129] DCI format 0_2 is used to schedule PUSCH in one cell. Information included in DCI format 0_2 is scrambled and transmitted by C-RNTI, CS-RNTI, SP-CSI-RNTI, or MCS-C-RNTI.

[0130] Next, DCI formats 1_0, 1_1 and 1_2 may include resource information (e.g., frequency resource allocation, time resource allocation, VRB (virtual resource block) -PRB (physical resource block) mapping, etc.), information related to transport blocks (TBs) (e.g., MCS, NDI, RV, etc.), information related to HARQ (e.g., process number, DAI, PDSCH-HARQ feedback timing, etc.), information related to multiple antennas (e.g., antenna ports, TCI (transmission configuration indicator), SRS (sounding reference signal) request, etc.), information related to PUCCH scheduling regarding PDSCH (e.g., PUCCH power control, PUCCH resource indicator, etc.), and the control information included in each DCI format may be predefined.

[0131] DCI format 1_0 is used to schedule PDSCH in one DL cell. Information included in DCI format 1_0 is CRC scrambled and transmitted by C-RNTI or CS-RNTI or MCS-C-RNTI.

[0132] DCI format 1_1 is used to schedule PDSCH in one cell. Information included in DCI format 1_1 is CRC scrambled and transmitted by C-RNTI or CS-RNTI or MCS-C-RNTI.

[0133] DCI format 1_2 is used to schedule PDSCH in one cell. Information included in DCI format 1_2 is CRC scrambled and transmitted by C-RNTI, CS-RNTI, or MCS-C-RNTI.

[0134] Wireless communication systems supporting unlicensed bands / shared spectrum

[0135] Figure 7 An example of a wireless communication system supporting an unlicensed frequency band applicable to the present disclosure is shown. For example, Fig. 9 An unlicensed spectrum (NR-U) wireless communication system is illustrated.

[0136] In the following description, a cell operating in a licensed band (L-band) is defined as an LCell, and a carrier of the LCell is defined as a (downlink / uplink) LCC. In addition, a cell operating in an unlicensed band (U-band) is defined as an UCell, and a carrier of the UCell is defined as a (downlink / uplink) UCC. The carrier / carrier frequency of a cell may represent an operating frequency (e.g., a center frequency) of the cell. Cells / carriers (e.g., component carriers (CCs)) are collectively referred to as cells.

[0137] like Figure 7 As shown in (a), when the terminal and the base station send and receive signals through carrier aggregation (CA) LCC and UCC, the LCC can be configured as a primary CC (PCC) and the UCC can be configured as a secondary CC (SCC). Figure 7 As shown in (b), the terminal and the base station can send and receive signals through one UCC or multiple UCCs combined with the carrier. That is, the terminal and the base station can send and receive signals only through the UCC without the LCC. For independent operation, PRACH, PUCCH, PUSCH, SRS transmission, etc. can be supported in UCell.

[0138] For example, the unlicensed frequency band may be included in a specific frequency range (e.g., from 52.6 GHz to 71 GHz) higher than the existing frequency ranges (e.g., FR1 and FR2). The specific frequency range may be referred to as FR2-2 (in which case, the existing FR2 (i.e., 24250 MHz to 52600 MHz) may be referred to as FR2-1) or may be referred to as FR3. The scope of the present disclosure is not limited to the names FR2-2 or FR3.

[0139] Uplink transmit and receive operations

[0140] Figure 8 is a diagram illustrating uplink transmission and reception operations in a wireless communication system to which the present disclosure can be applied.

[0141] refer to Figure 8 , the base station schedules uplink transmission, such as frequency / time resources, transmission layer, uplink precoder, MCS, etc. (S1501). Specifically, the base station can determine the beam used for PUSCH transmission to the UE through the above operations.

[0142] The UE receives DCI for uplink scheduling (ie, including scheduling information of a PUSCH) from the base station on the PDCCH (S1502).

[0143] DCI format 0_0, 0_1 or 0_2 can be used for uplink scheduling. Specifically, DCI format 0_1 ​​includes the following information: DCI format identifier, UL / SUL (supplemental uplink) indicator, bandwidth part indicator, frequency domain resource assignment, time domain resource assignment, frequency hopping flag, modulation and coding scheme (MCS), SRS resource indicator (SRI), precoding information and number of layers, antenna port, SRS request, DMRS sequence initialization, UL-SCH (uplink shared channel) indicator.

[0144] Specifically, the SRS resource configured in the SRS resource set associated with the "usage" of the higher layer parameter may be indicated by the SRS resource indicator field. In addition, "spatialRelationInfo" may be configured for each SRS resource, and its value may be one of {CRI, SSB, SRI}.

[0145] The UE transmits uplink data to the base station on the PUSCH (S1503).

[0146] When the UE detects a PDCCH including DCI formats 0_0, 0_1, and 0_2, the UE sends a PUSCH according to an indication of the corresponding DCI.

[0147] For PUSCH transmission, two transmission methods are supported: codebook-based transmission and non-codebook-based transmission:

[0148] i) When the higher layer parameter "txConfig" is set to "codebook", the UE is configured for codebook-based transmission. On the other hand, when the higher layer parameter "txConfig" is set to "nonCodebook", the UE is configured for non-codebook-based transmission. If the higher layer parameter "txConfig" is not set, the UE is not expected to be scheduled in DCI format 0_1. When PUSCH is scheduled in DCI format 0_0, PUSCH transmission is based on a single antenna port.

[0149] For codebook-based transmission, the PUSCH may be scheduled in DCI format 0_0, DCI format 0_1, DCI format 0_2, or semi-statically. If the PUSCH is scheduled in DCI format 0_1, the UE determines the PUSCH transmit precoder based on the SRI, TPMI (transmit precoding matrix indicator) and transmit rank from the DCI as given by the SRS resource indicator field and the precoding information and layer number field. TPMI is used to indicate the precoder to be applied across antenna ports and corresponds to the SRS resource selected by SRI when multiple SRS resources are configured.

[0150] Alternatively, if a single SRS resource is configured, the TPMI is used to indicate the precoder to be applied across antenna ports and corresponds to the single SRS resource. The transmit precoder is selected from an uplink codebook with the same number of antenna ports as the higher layer parameter "nrofSRS-Ports". When a UE is configured with the higher layer parameter "txConfig" set to "codebook", the UE is configured with at least one SRS resource. The SRI indicated in time slot n is associated with the most recent transmission of the SRS resource identified by the SRI, where the SRS resource precedes the PDCCH carrying the SRI (i.e., time slot n).

[0151] ii) For non-codebook based transmission, PUSCH may be scheduled in DCI format 0_0, DCI format 0_1 ​​or semi-statically. When multiple SRS resources are configured, the UE may determine the PUSCH precoder and transmission rank based on the wideband SRI, where the SRI is given by the SRS resource indicator in the DCI or by the higher layer parameter "srs-ResourceIndicator".

[0152] The UE uses one or more SRS resources for SRS transmission, where the number of SRS resources can be configured for simultaneous transmission within the same RB based on UE capabilities. Only one SRS port is configured for each SRS resource. Only one SRS resource can be configured with the high-level parameter "usage" set to "nonCodebook". The maximum number of SRS resources that can be configured for non-codebook based uplink transmission is 4. The SRI indicated in time slot n is associated with the most recent transmission of the SRS resource identified by the SRI, where the SRS transmission precedes the PDCCH carrying the SRI (i.e., time slot n).

[0153] PRACH repeated transmission and transmission power configuration method

[0154] In order to improve the UL coverage of the basic wireless communication system, a PRACH preamble repetition transmission operation may be performed. When the UE repeatedly transmits the PRACH preamble, a beam operation and / or power control method should be defined. Hereinafter, a method for configuring / controlling the transmission power when the UE performs PRACH preamble repetition transmission (or / and Msg.3 PUSCH repetition transmission) according to an embodiment of the present disclosure will be described.

[0155] The present disclosure can be applied in combination with the above content (e.g., NR frame structure, RACH process, U-band system, etc.). In addition, the method related to configuring the PRACH transmission timing described later can be equally applied to the uplink signal transmission and reception method.

[0156] For example, uplink transmission by a method related to PRACH transmission timing configuration described later may be performed in an L-cell and / or U-cell defined in an NR system or a U-band system.

[0157] Fig. 9 Detailed description is a diagram for describing an uplink transmission operation of a UE in a wireless communication system to which the present disclosure may be applied.

[0158] The UE may receive first configuration information related to repeated transmission of a PRACH preamble code from a base station (S910).

[0159] For example, the first configuration information may include information indicating / configuring the execution of repeated transmission of the PRACH preamble code, information related to the (maximum) number of repeated transmissions of the PRACH preamble code, information related to the power of the PRACH preamble code transmission, information about at least one RO / SSB through which the PRACH preamble code is transmitted, etc.

[0160] The first configuration information may be sent from the base station to the UE via at least one of higher layer signaling (eg, RRC message, SIB), MAC CE, or DCI.

[0161] The UE may perform repeated transmission of the first PRACH preamble code at a plurality of first ROs (random access channel opportunities) based on the first configuration information (S920).

[0162] Specifically, the UE may select the most preferred SSB among multiple SSBs transmitted from the base station, and select multiple first ROs among ROs mapped to the selected SSB. The UE may perform first PRACH preamble code repetition transmission across multiple first ROs based on the first configuration information.

[0163] And, power of repeated transmission of the first PRACH preamble code performed across multiple first ROs may be based on a first reference signal (RS) for obtaining a path loss value.

[0164] That is, within multiple first ROs (i.e., first RACH attempts) in which repeated transmission of the first PRACH preamble is performed, the same first reference signal can be set to obtain a path loss value. That is, while performing repeated transmission of the first PRACH preamble, the UE can maintain the first reference signal used to calculate the path loss value.

[0165] And, the UE may determine the power of repeated transmission of the first PRACH preamble code performed at multiple first ROs based on the first path loss value obtained through the first reference signal.

[0166] As an example of the present disclosure, after completing the repeated transmission of the first PRACH preamble code, within multiple second ROs (i.e., second RACH attempts) selected by the UE, the UE can determine the power of the repeated transmission of the second PRACH preamble code performed in multiple second ROs based on the second path loss value obtained through the second reference signal.

[0167] That is, after the first RACH attempt is terminated, the UE may configure a new reference signal (i.e., a second reference signal) for calculating the path loss value in the second RACH attempt. Then, the UE may determine the power of repeated transmissions of the second PRACH preamble code performed at multiple second ROs based on the second path loss value by using the new reference signal.

[0168] As an example of the present disclosure, the transmit power ramp may not be applied within multiple first ROs (ie, not within the first RACH attempt). That is, the counter value for the preamble power ramp may be maintained at the same value within multiple first ROs performing the first PRACH preamble repetition transmission.

[0169] Additionally or alternatively, a counter value related to the number of preamble transmissions within a plurality of first ROs performing repeated transmissions of the first PRACH preamble may be maintained at the same value.

[0170] In another example of the present disclosure, based on that the repeated transmission of the first PRACH preamble code is stopped, within multiple third ROs selected by the UE after multiple first ROs, the UE can determine the power of the repeated transmission of the third PRACH preamble code performed in multiple third ROs based on a third path loss value obtained through a third reference signal.

[0171] Here, whether to allow stopping the repeated transmission of the first PRACH preamble code may be configured by the base station. For example, the UE may receive second configuration information configuring whether to allow stopping the transmission of the first PRACH preamble code from the base station.

[0172] As another example, the UE may send capability information to the base station regarding whether it supports the capability of allowing stopping of repeated transmission of the first PRACH preamble code. Based on the capability information sent by the UE to the base station, it may be determined whether stopping of repeated transmission of the first PRACH preamble code is allowed.

[0173] For example, if the capability information indicates that the UE supports allowing stopping of repeated transmission of the first PRACH preamble code, repeated transmission of the first PRACH preamble code may be allowed.

[0174] As another example, based on the PDCCH order indicating contention-free random access (CFRA), stopping the repeated transmission of the first PRACH preamble code may not be allowed.

[0175] Fig.10 Detailed description is a diagram for describing an uplink reception operation of a base station in a wireless communication system to which the present disclosure may be applied.

[0176] The base station may send first configuration information related to repeated transmission of a PRACH preamble code to the UE (S1010).

[0177] For example, the base station may send first configuration information to the UE including the following items: information on whether to perform repeated transmission of the PRACH preamble code, the maximum number of repeated transmissions of the PRACH preamble code, information related to the power of the PRACH preamble code transmission, and information on at least one RO / SSB for sending the PRACH preamble code.

[0178] The base station may perform repeated reception of the first PRACH preamble code at a plurality of first ROs based on the first configuration information (S1020).

[0179] For example, the base station may send at least one reference signal for calculating the path loss to the UE. A first reference signal among at least one reference signal within a plurality of first ROs may be configured / determined to be used for calculating the path loss. That is, within the plurality of first ROs, the reference signal for calculating the path loss may be maintained as the first reference signal.

[0180] Hereinafter, a method for repeating PRACH transmission and a method for controlling / setting transmission power to improve the coverage of a wireless communication system are described in detail.

[0181] Implementation Method 1

[0182] Embodiment 1 relates to a method for setting transmit (Tx) power during repeated transmission of a PRACH preamble.

[0183] When the UE is configured / instructed to repeatedly transmit a PRACH preamble and repeatedly transmits the PRACH preamble starting from the configured / instructed RO, the Tx beam direction of the repeatedly transmitted PRACH preamble may be configured / instructed / defined to be the same.

[0184] However, regarding the Tx power between PRACH preamble codes (regardless of whether the Tx beam direction of the repeatedly transmitted PRACH preamble codes is the same), when the UE repeatedly sends the PRACH preamble code at multiple RO (RACH occasions), the Tx power between the repeatedly transmitted PRACH preamble codes can be configured / indicated / defined to be maintained at the same value.

[0185] For example, the UE may be configured / instructed to apply the same value of the preamble power ramping counter (PREAMBLE_POWER_RAMPING_COUNTER) to multiple ROs containing repeatedly transmitted PRACH preambles.

[0186] That is, the UE may be configured to maintain the PREAMBLE_POWER_RAMPING_COUNTER at the same value without increasing the PREAMBLE_POWER_RAMPING_COUNTER during repeated transmission of the PRACH preamble (before the end of a specific repeated transmission). In addition, the UE may be configured to maintain the PREAMBLE_TRANSMISSION_COUNTER at the same value without increasing the PREAMBLE_TRANSMISSION_COUNTER during repeated transmission of the PRACH preamble (before the end of a specific repeated transmission).

[0187] The above method can be Fig.11 As an example, Fig.11 As shown in (a), it is assumed that the base station sets the terminal to perform PRACH preamble retransmission twice in total and PRACH preamble retransmission four times in total. The UE can send the PRACH preamble four times in total (including three retransmissions due to failure to receive a random access response (RAR) in the middle). Therefore, Fig.11 As shown in (a), the UE can perform repeated transmission and retransmission by selecting RO.

[0188] Implementation Method 2

[0189] Embodiment 2 relates to the operation of the UE / base station when the UE's most preferred SSB index changes during repeated transmission of the PRACH preamble code.

[0190] The UE may select multiple ROs to repeatedly transmit the PRACH preamble code. From the perspective of the UE, the UE may select multiple ROs mapped to the SSB index with the best reception performance (ie, the SSB index most preferred by the UE).

[0191] Here, although the UE performs repeated PRACH preamble transmission using a plurality of ROs selected from among ROs mapped to the UE's initially most preferred SSB index, the UE's most preferred SSB index may be changed.

[0192] As described above, if the UE's most preferred SSB index changes during PRACH preamble retransmission, it may be undesirable for the terminal to reselect a new RO and perform PRACH preamble retransmission from the perspective of terminal / base station implementation and system complexity.

[0193] Implementation Method 2-1

[0194] Even if the UE's most preferred SSB index changes during PRACH preamble retransmission, the UE may be configured not to reselect a new RO and perform retransmission. That is, even if the UE's most preferred SSB index changes during PRACH preamble retransmission, the UE may perform PRACH preamble retransmission using the previously selected RO without performing RO reselection.

[0195] The above method can be Fig.11 For example, Fig.11 As shown in (b), it is assumed that the base station configures the UE to perform PRACH preamble retransmission twice in total and performs PRACH preamble retransmission four times in total. If the UE is not allowed to select a new RO even if the most preferred SSB index changes during PRACH preamble retransmission, the UE can send the PRACH preamble four times in total (including three retransmissions due to failure to receive a random access response (RAR) in the middle). Therefore, Fig.11 As shown in (b), the UE can perform PRACH preamble code repetition and retransmission by selecting RO.

[0196] Implementation method 2-2

[0197] If the UE's most preferred SSB index changes during PRACH preamble repetition transmission, the UE may be configured / defined to stop PRACH preamble repetition transmission instead of continuing PRACH preamble repetition transmission.

[0198] As another example, the base station may be configured to allow the UE to stop repetitive transmission of the PRACH preamble (when the UE's most preferred SSB index changes). As an example, the base station may send / provide a parameter indicating / configuring whether the PRACH preamble repetitive transmission may be stopped to the UE via high-layer signaling (e.g., RRC message, SIB (system information block), etc.).

[0199] Additionally or alternatively, if a parameter indicating / configuring whether PRACH preamble repetition transmission can be stopped is not sent / provided to the UE, the UE may be configured to understand that PRACH preamble repetition transmission may be stopped (or not stopped) by default.

[0200] For example, assume that the base station configures / instructs the UE to be able to stop PRACH preamble repetition transmission (or, allows the UE to stop PRACH preamble repetition transmission). If the most preferred SSB index changes in the middle of PRACH preamble repetition transmission, the UE may stop the existing PRACH preamble repetition transmission (or / and the UE does not expect to receive RAR for the existing PRACH preamble repetition transmission). The UE may then be configured to continue the RACH process by newly selecting multiple ROs mapped to the newly selected SSB index after the (predefined / instructed) processing time required for selecting a new RO and / or beam switching, etc. has passed.

[0201] Additionally or alternatively, even if repeated transmission of an existing PRACH preamble is stopped, the UE may be configured to expect to receive a RAR for a previously transmitted PRACH preamble. In this case, if the UE receives a RAR for a previously transmitted PRACH preamble, the UE may perform Msg.3 PUSCH transmission based on the RAR. If the UE does not receive a RAR for a previously transmitted PRACH preamble, the UE may be configured to select a new RO according to a newly selected SSB index.

[0202] Additionally or alternatively, the UE may be configured / instructed / defined to stop repeating the PRACH preamble transmission only when the beam direction of the newly selected SSB index is different from the beam direction of the previously selected SSB index.

[0203] Here, if a new PRACH preamble repetition transmission is started at a newly selected RO, power ramping may not be allowed (compared to the existing repetition transmission). That is, if a new PRACH preamble repetition transmission is started at a newly selected RO, PREAMBLE_POWER_RAMPING_COUNTER may be configured / defined not to increase. In addition, if the UE starts a new PRACH preamble repetition transmission after stopping performing PRACH preamble repetition transmission, PREAMBLE_TRANSMISSION_COUNTER may be configured / defined to increase.

[0204] The above method can be Fig.11 As an example, Fig.11 As shown in (c), it is assumed that the base station configures the UE to be able to perform PRACH preamble retransmission twice in total and PRACH preamble retransmission four times in total. If the most preferred SSB index changes during PRACH preamble retransmission, the UE can be configured to stop the existing PRACH preamble retransmission and reselect a new RO to continue the RACH process.

[0205] For example, if the UE determines that the most preferred SSB index has changed at the second retransmission time point (the third transmission time point in total including the initial transmission), the UE can immediately stop retransmitting the existing PRACH preamble code, select a new RO, and continue the RACH process.

[0206] Here, if Fig.11 As shown in (c), considering the situation that the beam direction of the newly selected SSB index of the UE is different from the beam direction of the previously selected SSB index, PREAMBLE_TRANSMISSION_COUNTER (i.e., PRACH preamble code transmission related counter) may increase, but PREAMBLE_POWER_RAMPING_COUNTER may not increase.

[0207] Therefore, when PREAMBLE_TRANSMISSION_COUNTER is equal to the maximum number of PRACH preamble transmissions (eg, 'preambleTransMax' value) when performing existing PRACH preamble repetition transmissions, the UE may be configured / defined not to stop existing PRACH preamble repetition transmissions (ie, configured / defined not to allow stopping of PRACH preamble repetition transmissions).

[0208] Here, if PREAMBLE_TRANSMISSION_COUNTER is equal to the 'preamleTransMax' value when performing the existing PRACH preamble repetition transmission, this means that the UE stops the PRACH preamble repetition transmission and attempts to perform new repetition transmission, but when the PREAMBLE_TRANSMISSION_COUNTER value increases by 1, the PREAMBLE_TRANSMISSION_COUNTER value becomes greater than 'preamleTransMax', so new PRACH preamble repetition transmission cannot be performed. That is, since the PREAMBLE_TRANSMISSION_COUNTER value becomes 'preambleTransMax+1', the UE may not be able to perform new PRACH preamble repetition transmission.

[0209] Implementation 2-3

[0210] If the base station configures / indicates that PRACH preamble repetition interruption is not possible (or, PRACH preamble repetition interruption is not allowed), the UE can be configured / instructed to continue the existing PRACH preamble repetition even if the most preferred SSB index changes during PRACH preamble repetition.

[0211] However, assume that the UE's preferred SSB index has changed between the time point when the existing PRACH preamble repetition transmission is completed and the time point when the retransmission starts (when the UE expects to receive the RAR but fails to receive the RAR). In this case, the UE can select multiple ROs among the ROs mapped to the newly selected SSB index and perform retransmission for the PRACH preamble repetition transmission without power ramping (compared to the existing retransmission).

[0212] The above method can be Fig.11 As an example, Fig.11 As shown in (d), it is assumed that the base station configures the UE to be able to perform PRACH preamble retransmission twice in total and PRACH preamble retransmission four times in total. In addition, it is assumed that even if the most preferred SSB index changes in the middle of PRACH preamble retransmission, it is not allowed to stop the existing PRACH preamble retransmission. If the time when the UE's most preferred SSB index changes is within a specific time, the UE can select the RO mapped to the new index before the third retransmission (the fourth transmission if the initial transmission is included) and continue the RACH process.

[0213] Here, the specific time point may mean a time period from the end of a specific repetition transmission until the start of the next repetition transmission (and / or including the RO selection time).

[0214] For example, refer to Fig.11 (d), considering the situation that the newly selected SSB index is different from the previously selected SSB index, the value associated with PREAMBLE_TRANSMISSION_COUNTER may be increased, but the value associated with PREAMBLE_POWER_RAMPING_COUNTER may not be increased.

[0215] Implementation 2-4

[0216] In the above embodiment, regardless of whether the PRACH preamble code repetition transmission is stopped, when the UE changes the beam by retransmitting the PRACH preamble code, the value related to PREAMBLE_TRANSMISSION_COUNTER increases, and the value related to PREAMBLE_POWER_RAMPING_COUNTER does not increase.

[0217] In a basic wireless communication system, a single PRACH preamble is transmitted, but the present disclosure describes an implementation of repeatedly transmitting the PRACH preamble. Therefore, when the UE changes the PRACH transmission beam, the UE may initialize PREAMBLE_TRANSMISSION_COUNTER and / or PREAMBLE_POWER_RAMPING_COUNTER to an initial setting value (e.g., 1) and continue the RACH process.

[0218] That is, if the SSB-RSRP of the SSB newly selected by the UE is greater than a specific value (or if the RSRP change amount is greater than the threshold when the base station provides the UE with a threshold for the RSRP change amount), the PREAMBLE_TRANSMISSION_COUNTER and / or PREAMBLE_POWER_RAMPING_COUNTER may be reset.

[0219] As another example, if the SSB-RSRP of the newly selected SSB is below a certain value (or if the RSRP change is within a threshold provided by the base station), the PREAMBLE_TRANSMISSION_COUNTER and / or PREAMBLE_POWER_RAMPING_COUNTER values ​​may be set to remain.

[0220] Implementation 2-5

[0221] It can be preset to determine whether to allow stopping the repeated transmission of the PRACH preamble code according to a specific service scenario. For example, in a terrestrial network (TN) such as NR or / and LTE where the round-trip delay is not large, stopping the repeated transmission of the PRACH preamble code can be set to not be allowed. In addition, in the case of a large round-trip delay such as a non-terrestrial network (NTN) and / or air-to-ground (ATG), the interruption of the repeated transmission of the PRACH preamble code can be set to be allowed.

[0222] Here, if it is confirmed through higher signaling (eg, RRC message, SIB, etc.) that the current service is a TN service, the UE may determine that stopping repeatedly transmitting the PRACH preamble is not allowed.

[0223] As another example, if it is confirmed (via higher layer signaling) that the current service is an NTN service, the UE may determine that stopping repeated transmission of the PRACH preamble is allowed.

[0224] Alternatively, a UE capability for whether to stop repetitive transmission of the PRACH preamble code can be introduced. Depending on the UE capability of the UE (i.e., depending on the capability information related to whether the PRACH preamble code repetitive transmission can be stopped sent by the terminal to the base station), stopping the PRACH preamble code repetitive transmission may be allowed or not allowed.

[0225] Additionally or alternatively, if CFRA (contention-free random access) is indicated by a PDCCH command, the DCI (i.e., PDCCH) of the PDCCH command may be sent to indicate to the terminal whether PRACH preamble repetition transmission suspension is allowed. Here, the UE may determine whether PRACH preamble repetition transmission suspension is allowed by sending the DCI of the PDCCH command.

[0226] Additionally or alternatively, whether to stop PRACH preamble repetition transmission may be configured / defined according to RA type (ie, contention-based random access (CBRA) and CFRA).

[0227] That is, when the PDCCH command indicates CFRA, the base station can select the RO corresponding to the best UL beam for the corresponding UE. Therefore, when CFRA is indicated by the PDCCH command, it can be set so that the repeated transmission of the PRACH preamble code is not allowed to be stopped.

[0228] The SSB used in the above-mentioned embodiments may be replaced by other types of reference signals and / or CSI-RS, etc. That is, other types of reference signals and / or CSI-RS, etc. may be applied to the above-mentioned embodiments.

[0229] In addition, in the above embodiments, the best UL index may be considered together with (or instead of) the best SSB index, and the best UL index may be based on the operation of selecting NUL or SUL.

[0230] In addition, the above embodiment describes the following case: when a better SSB index exists, the terminal changes the SSB index regardless of the RSRP value of the existing SSB index.

[0231] As another example, the terminal may be configured / defined to select the best SSB index only when the RSRP of the currently selected SSB index is below a certain pre-configured / indicated threshold.

[0232] Implementation 3

[0233] Embodiment 3 relates to a method of setting a reference signal for calculating a path loss during repeated transmission of a PRACH preamble.

[0234] For example, assuming that the UE first uses the RO (selected by the terminal) among the ROs mapped to the most preferred SSB index to perform PRACH preamble repetition transmission, the UE's most preferred SSB index is changed, but the existing PRACH preamble repetition transmission continues. In this case, if the operation according to the basic wireless communication system is performed, the path loss value can be changed in terms of UL Tx power control.

[0235] As described above, there is a problem in that when the path loss value changes, the UL Tx power calculated based on the path loss value may change during PRACH preamble repetition transmission.

[0236] Therefore, when the terminal's most preferred SSB index changes while performing PRACH preamble repetition, if the existing PRACH preamble repetition is continued, the UE can keep the reference signal used for path loss calculation the same. And, the UE can apply the calculated path loss value to the power control operation when receiving the path loss measurement reference signal.

[0237] Additionally or alternatively, when performing PRACH preamble retransmission, it is assumed that the UE stops the existing PRACH preamble retransmission when the UE's most preferred SSB index changes (in the case where retransmission stopping is allowed). Here, if the UE is to perform new retransmission by selecting multiple ROs corresponding to the new SSB index, the UE may be configured to change the reference signal used for path loss calculation based on the new SSB index.

[0238] The above-mentioned embodiments may be set / applied to other UL signals / channels, such as Msg.3PUSCH, MSGA preamble / PUSCH and / or PUSCH / PUCCH. That is, in the above-mentioned embodiments, the 'PRACH preamble' may be replaced by other UL signals / channels, such as Msg.3PUSCH, MSGA preamble / PUSCH and / or PUSCH / PUCCH. In addition, it is obvious that the above-mentioned embodiments may also be included as one of the implementation methods of the present disclosure, and thus may be considered as an implementation method.

[0239] In addition, the above embodiments may be implemented independently, but may also be implemented in the form of a combination (or merger) of some embodiments. Information about whether the above embodiments are applicable (or information about the rules of the embodiments) may be defined so that the rules are defined so that the base station notifies the UE through a predefined signal (e.g., a physical layer signal or a high-layer signal). The high layer may include, for example, one or more functional layers such as MAC, RLC, PDCP, RRC, and SDAP.

[0240] Fig.12It is a diagram for describing the signaling process between the network side and the terminal according to an embodiment of the present disclosure.

[0241] Fig.12 An example of signaling between the network side and the terminal (UE) in the M-TRP case to which the above-disclosed embodiments (e.g., embodiment 1, embodiment 2, embodiment 2-1, embodiment 2-2, embodiment 2-3, embodiment 2-4, embodiment 2-5, embodiment 3 or one or more combinations thereof in their detailed examples) can be applied is shown.

[0242] Here, UE / network side is an example and can be replaced by reference Fig.13 The various devices described. Fig.12 This is for the convenience of explanation and does not limit the scope of the present disclosure. In addition, depending on the situation and / or setting, it can be omitted Fig.12 In addition, Fig.12 In the network side / UE operations, the above-mentioned uplink sending / receiving operations, M-TRP related operations, etc. can be referred to or used.

[0243] In the following description, the network side may be a base station including multiple TRPs, or a cell including multiple TRPs. Alternatively, the network side may include multiple remote radio heads (RRH) / remote radio units (RRU). For example, an ideal / non-ideal backhaul may be set between TRP 1 and TRP 2, which constitutes the network side. In addition, the following description is based on multiple TRPs, but can be equally extended and applied to transmission through multiple panels / cells, and can also be extended and applied to transmission through multiple RRH / RRUs, etc.

[0244] In addition, in the following description, it is described based on "TRP", but as described above, "TRP" can also be applied by replacing it with expressions such as panel, antenna array, cell (e.g., macro cell / small cell / pico cell, etc.), TP (transmission point), base station (gNB, etc.). As described above, TRP can be classified according to information about the CORESET group (or CORESET pool) (e.g., CORESET index, ID).

[0245] For example, if a single UE is configured to transmit and receive using multiple TRPs (or cells), this may mean that multiple CORESET groups (or CORESET pools) are configured for a single terminal. The configuration of such a CORESET group (or CORESET pool) may be performed via higher layer signaling (e.g., RRC signaling, etc.).

[0246] In addition, a base station can generally refer to an object that sends and receives data with a terminal. For example, a base station can be a concept including at least one TP (transmission point), at least one TRP (transmit and receive point), etc. In addition, TP and / or TRP can include a panel, a sending and receiving unit, etc. of the base station.

[0247] refer to Fig.13 , a base station (eg, BS) may periodically send an SSB to a terminal (S1202). Here, the SSB may include PSS / SSS / PBCH. The base station may send the SSB to the UE using beam scanning.

[0248] The base station may send remaining minimum system information (RMSI) and other system information (OSI) to the terminal (S1204). RMSI may include information required for the terminal to initially access the base station (eg, PRACH configuration information). Here, the UE may identify the best SSB after performing SSB detection.

[0249] Thereafter, the UE may send a RACH preamble (message 1, Msg1) to the base station using a PRACH resource associated / corresponding to the index (ie, beam) of the best SSB (S1206).

[0250] The beam direction of the RACH preamble may be associated with the PRACH resource. The association between the PRACH resource (and / or the RACH preamble) and the SSB index may be established via system information (eg, RMSI).

[0251] Here, the UE may perform PRACH preamble repetition transmission. The UE may perform PRACH preamble repetition transmission based on configuration information related to PRACH repetition transmission received from the base station.

[0252] Thereafter, as part of the RACH procedure, the base station may send a random access response (RAR) (Msg2) to the terminal in response to the PRACH preamble (S1208).

[0253] The RAR may include at least one of a field related to PUSCH repetition transmission, a field for indicating whether to repeat PUSCH preamble transmission, or a PUSCH time / frequency resource field.

[0254] The UE may send a Msg.3 PUSCH (eg, RRC Connection Request) using the uplink grant in the RAR (S1210).

[0255] The UE may perform PUSCH repetition transmission based on the RAR. Here, the number of PUSCH repetition transmissions may be based on the number of PRACH preamble repetition transmissions.

[0256] The base station may send a contention resolution message (Msg4) to the terminal (S1212). Msg4 may include RRC connection establishment.

[0257] When an RRC connection is established between a base station and a UE through a RACH process, subsequent beam alignment may be performed based on SSB / CSI-RS (in downlink) and SRS (in uplink). For example, the UE may receive SSB / CSI-RS (S1214). The UE may use SSB / CSI-RS to generate a beam / CSI report.

[0258] And the base station can request the UE to report the beam / CSI through DCI (S1216). Here, the UE can generate a beam / CSI report based on the SSB / CSI-RS, and send the generated beam / CSI report to the base station through PUSCH / PUCCH (S1218). The beam / CSI report may include beam measurement results, information about the preferred beam, etc. The base station and the UE can switch beams based on the beam / CSI report (S1220a, S1220b).

[0259] Thereafter, the UE and the base station may perform the above-described / proposed embodiments. For example, according to an embodiment of the present disclosure, the UE and the base station may process the information in the memory and send a wireless signal or process the received wireless signal and store it in the memory based on the configuration information obtained in the network access process (e.g., the system information acquisition process, the RRC connection process via RACH, etc.). Here, the wireless signal may include at least one of PDCCH, PDSCH, and RS (reference signal) in the downlink case, and at least one of PUCCH, PUSCH, and SRS in the uplink case.

[0260] General devices to which the present disclosure can be applied

[0261] Fig.13 is a diagram illustrating a block diagram of a wireless communication system according to an embodiment of the present disclosure.

[0262] refer to Fig.13 , the first device 100 and the second device 200 can send and receive wireless signals through various radio access technologies (e.g., LTE, NR).

[0263] The first device 100 may include one or more processors 102 and one or more memories 104, and may further include one or more transceivers 106 and / or one or more antennas 108. The processor 102 may control the memory 104 and / or the transceiver 106, and may be configured to implement the descriptions, functions, processes, suggestions, methods, and / or operational flow charts included in the present disclosure.

[0264] For example, the processor 102 may generate the first information / signal by processing the information in the memory 104, and then transmit the wireless signal including the first information / signal through the transceiver 106. In addition, the processor 102 may receive the wireless signal including the second information / signal through the transceiver 106, and then store the information obtained by signal processing of the second information / signal in the memory 104.

[0265] The memory 104 may be connected to the processor 102 and may store various information related to the operation of the processor 102. For example, the memory 104 may store software code including commands for executing all or part of the processing controlled by the processor 102 or for executing the descriptions, functions, processes, suggestions, methods and / or operational flow charts included in the present disclosure. Here, the processor 102 and the memory 104 may be part of a communication modem / circuit / chip designed to implement wireless communication technology (e.g., LTE, NR). The transceiver 106 may be connected to the processor 102 and may send and / or receive wireless signals through one or more antennas 108. The transceiver 106 may include a transmitter and / or a receiver. The transceiver 106 may be used in conjunction with an RF (radio frequency) unit. In the present disclosure, a wireless device may refer to a communication modem / circuit / chip.

[0266] The second device 200 may include one or more processors 202 and one or more memories 204, and may further include one or more transceivers 206 and / or one or more antennas 208. The processor 202 may control the memory 204 and / or the transceiver 206, and may be configured to implement the descriptions, functions, processes, suggestions, methods, and / or operational flowcharts included in the present disclosure. For example, the processor 202 may generate third information / signals by processing the information in the memory 204, and then send a wireless signal including the third information / signal through the transceiver 206. In addition, the processor 202 may receive a wireless signal including fourth information / signals through the transceiver 206, and then store information obtained by signal processing of the fourth information / signal in the memory 204. The memory 204 may be connected to the processor 202 and may store various information related to the operation of the processor 202. For example, the memory 204 may store software codes including commands for executing all or part of the processing controlled by the processor 202 or for executing the descriptions, functions, processes, suggestions, methods, and / or operational flowcharts included in the present disclosure. Here, the processor 202 and the memory 204 may be part of a communication modem / circuit / chip designed to implement wireless communication technology (e.g., LTE, NR). The transceiver 206 may be connected to the processor 202 and may send and / or receive wireless signals through one or more antennas 208. The transceiver 206 may include a transmitter and / or a receiver. The transceiver 206 may be used in conjunction with an RF unit. In the present disclosure, a wireless device may refer to a communication modem / circuit / chip.

[0267] In the following, the hardware elements of the apparatus 100, 200 will be described in more detail. Without limitation thereto, one or more protocol layers may be implemented by one or more processors 102, 202. For example, one or more processors 102, 202 may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). One or more processors 102, 202 may generate one or more PDUs (protocol data units) and / or one or more SDUs (service data units) according to the descriptions, functions, processes, suggestions, methods, and / or operational flowcharts included in the present disclosure. One or more processors 102, 202 may generate messages, control information, data, or information according to the descriptions, functions, processes, suggestions, methods, and / or operational flowcharts included in the present disclosure. One or more processors 102, 202 may generate a signal (e.g., a baseband signal) including a PDU, SDU, message, control information, data, or information to provide to one or more transceivers 106, 206 in accordance with the functions, processes, suggestions, and / or methods included in the present disclosure.

[0268] One or more processors 102, 202 may receive a signal (e.g., a baseband signal) from one or more transceivers 106, 206 according to the description, function, process, suggestion, method and / or operational flowchart included in the present disclosure, and obtain PDU, SDU, message, control information, data or information. One or more processors 102, 202 may be referred to as a controller, a microcontroller, a microprocessor or a microcomputer. One or more processors 102, 202 may be implemented by hardware, firmware, software or a combination thereof. For example, one or more ASICs (application specific integrated circuits), one or more DSPs (digital signal processors), one or more DSPDs (digital signal processing devices), one or more PLDs (programmable logic devices) or one or more FPGAs (field programmable gate arrays) may be included in one or more processors 102, 202. The description, function, process, suggestion, method and / or operational flowchart included in the present disclosure may be implemented by using firmware or software, and the firmware or software may be implemented to include modules, processes, functions, etc. Firmware or software configured to perform the descriptions, functions, processes, suggestions, methods and / or operational flowcharts included in the present disclosure may be included in one or more processors 102, 202, or may be stored in one or more memories 104, 204 and driven by one or more processors 102, 202. The descriptions, functions, processes, suggestions, methods and / or operational flowcharts included in the present disclosure may be implemented by using firmware or software in the form of codes, commands and / or command sets.

[0269] One or more memories 104, 204 may be connected to one or more processors 102, 202 and may store data, signals, messages, information, programs, codes, instructions, and / or commands in various forms. One or more memories 104, 204 may be configured with ROM, RAM, EPROM, flash memory, hard drive, registers, cache memory, computer-readable storage media, and / or combinations thereof. One or more memories 104, 204 may be located inside and / or outside one or more processors 102, 202. In addition, one or more memories 104, 204 may be connected to one or more processors 102, 202 via various technologies such as wired or wireless connections.

[0270] One or more transceivers 106, 206 may send user data, control information, wireless signals / channels, etc. mentioned in the method and / or operation flow chart of the present disclosure to one or more other devices. One or more transceivers 106, 206 may receive user data, control information, wireless signals / channels, etc. mentioned in the description, function, process, suggestion, method and / or operation flow chart, etc. included in the present disclosure from one or more other devices. For example, one or more transceivers 106, 206 may be connected to one or more processors 102, 202 and may send and receive wireless signals. For example, one or more processors 102, 202 may control one or more transceivers 106, 206 to send user data, control information or wireless signals to one or more other devices. In addition, one or more processors 102, 202 may control one or more transceivers 106, 206 to receive user data, control information or wireless signals from one or more other devices. In addition, one or more transceivers 106, 206 may be connected to one or more antennas 108, 208, and one or more transceivers 106, 206 may be configured to send and receive user data, control information, wireless signals / channels, etc. mentioned in the description, functions, processes, suggestions, methods and / or operation flow charts, etc. included in the present disclosure through one or more antennas 108, 208. In the present disclosure, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers 106, 206 may convert received wireless signals / channels, etc. from RF band signals into baseband signals to process received user data, control information, wireless signals / channels, etc. by using one or more processors 102, 202. One or more transceivers 106, 206 may convert user data, control information, wireless signals / channels, etc. processed by using one or more processors 102, 202 from baseband signals into RF band signals. Thus, one or more of the transceivers 106 , 206 may include (analog) oscillators and / or filters.

[0271] The above-mentioned embodiments are to combine the elements and features of the present disclosure in a predetermined form. Unless otherwise explicitly mentioned, each element or feature should be regarded as optional. Each element or feature can be implemented in a form that is not combined with other elements or features. In addition, the embodiments of the present disclosure may include a combination of some elements and / or features. The order of the operations described in the embodiments of the present disclosure may be changed. Some elements or features of an embodiment may be included in other embodiments, or may be replaced by corresponding elements or features of other embodiments. Obviously, the embodiments may include claims that do not have a clear reference relationship in the combined claims, or may be included as new claims by modification after application.

[0272] It is clear to those skilled in the relevant art that the present disclosure can be implemented in other specific forms within the scope of the essential features of the present disclosure. Therefore, the above detailed description should not be interpreted restrictively in every aspect, but should be considered as illustrative. The scope of the present disclosure should be determined by the reasonable interpretation of the attached claims, and all changes within the equivalent scope of the present disclosure are included in the scope of the present disclosure.

[0273] The scope of the present disclosure includes software or machine executable commands (e.g., operating systems, applications, firmware, programs, etc.) that perform operations in a device or computer according to the methods of various embodiments, and non-transitory computer-readable media that enable software or commands, etc. to be stored and executable in a device or computer. Commands that can be used to program a processing system that performs the features described in the present disclosure can be stored in a storage medium or a computer-readable storage medium, and the features described in the present disclosure can be implemented by using a computer program product that includes such a storage medium. The storage medium may include a high-speed random access memory, such as, for example, DRAM, SRAM, DDR RAM, or other random access solid-state storage devices, but is not limited thereto, and it may include non-volatile memory, such as, for example, one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid-state storage devices. The memory optionally includes one or more storage devices located away from the processor. The memory, or alternatively, the non-volatile memory device in the memory includes a non-transitory computer-readable storage medium. The features described in this disclosure may be stored in any machine-readable medium to control the hardware of a processing system, and may be integrated into software and / or firmware that allows the processing system to interact with other mechanisms using the results from the embodiments of this disclosure. Such software or firmware may include, but is not limited to, application code, device drivers, operating systems, and execution environments / containers.

[0274] Here, the wireless communication technology implemented in the apparatus 100, 200 of the present disclosure may include narrowband Internet of Things for low-power communication as well as LTE, NR and 6G. Here, for example, NB-IoT technology may be an example of LPWAN (Low Power Wide Area Network) technology, which may be implemented in standards such as LTE Cat NB1 and / or LTE Cat NB2 and is not limited to the above names. Additionally or alternatively, the wireless communication technology implemented in the wireless apparatus 100, 200 of the present disclosure may perform communication based on LTE-M technology. Here, for example, LTE-M technology may be an example of LPWAN technology and may be referred to as various names such as eMTC (enhanced machine type communication). For example, LTE-M technology may be implemented in at least any one of various standards, including 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, etc., and is not limited to the above names. Additionally or alternatively, the wireless communication technology implemented in the wireless devices 100, 200 of the present disclosure may include at least any one of ZigBee, Bluetooth, and a low power wide area network (LPWAN) considering low power communication, and is not limited to the above names. For example, ZigBee technology can generate a PAN (Personal Area Network) related to small / low power digital communication based on various standards (e.g., IEEE 802.15.4, etc.), and can be called various names.

[0275] Industrial Applicability

[0276] The method proposed in the present disclosure is mainly described based on examples applied to 3GPP LTE / LTE-A and 5G systems, but can also be applied to various wireless communication systems other than 3GPP LTE / LTE-A and 5G systems.

Claims

1. A method performed by a user equipment UE in a wireless communication system, the method comprising the following steps: receiving first configuration information related to repeated transmission of a physical random access channel PRACH preamble code from a base station; as well as Based on the first configuration information, repeatedly sending a first PRACH preamble code in multiple first random access channel opportunities RO, wherein the power of the repeated transmission of the first PRACH preamble code performed across the plurality of first ROs is based on a first reference signal RS for obtaining a path loss value, and Wherein, the transmit power ramp-up is not applied in the plurality of first ROs.

2. The method according to claim 1, wherein: A counter value for preamble power ramping is maintained at the same value within the plurality of first ROs performing the repeated transmission of the first PRACH preamble.

3. The method according to claim 1, wherein: The power of the repeated transmission of the first PRACH preamble code performed in the plurality of first ROs is determined based on a first path loss value obtained through the first reference signal.

4. The method according to claim 1, wherein: After completing the repeated transmission of the first PRACH preamble code, power of repeated transmission of the second PRACH preamble code performed in a plurality of second ROs selected by the UE is determined based on a second path loss value obtained through a second reference signal.

5. The method according to claim 1, wherein: Based on the repeated transmission of the first PRACH preamble code being stopped, based on the third path loss value obtained through the third reference signal, the power of the repeated transmission of the third PRACH preamble code performed in the multiple third ROs selected by the UE after the multiple first ROs is determined.

6. The method according to claim 1, wherein: A counter value associated with the number of preamble transmissions within the plurality of first ROs performing the repeated transmissions of the first PRACH preamble is maintained at the same value.

7. The method according to claim 1, wherein: Second configuration information for configuring whether to allow stopping the repeated transmission of the first PRACH preamble code is received from the base station.

8. The method according to claim 1, wherein: sending, to the base station, capability information related to whether to support allowing stopping the repeated transmission of the first PRACH preamble code, and Determine whether stopping the repeated transmission of the first PRACH preamble code is allowed based on the capability information.

9. The method according to claim 1, wherein: Based on indicating contention-free random access CFRA through a physical downlink control channel PDCCH command, it is not allowed to stop the repeated transmission of the first PRACH preamble code.

10. A user equipment UE in a wireless communication system, the UE comprising: at least one transceiver; as well as at least one processor connected to the at least one transceiver, Wherein, the at least one processor is configured to: receiving, by the at least one transceiver, first configuration information related to repeated transmission of a physical random access channel (PRACH) preamble from a base station; and Based on the first configuration information, repeatedly sending a first PRACH preamble code in multiple first random access channel opportunities RO, wherein the power of the repeated transmission of the first PRACH preamble code performed across the plurality of first ROs is based on a first reference signal RS for obtaining a path loss value, and Wherein, the transmit power ramp-up is not applied in the plurality of first ROs.

11. A method performed by a base station in a wireless communication system, the method comprising the following steps: Sending first configuration information related to repeated transmission of a physical random access channel PRACH preamble code to a user equipment UE; as well as performing repeated reception of a first PRACH preamble code in a plurality of first random access channel opportunities RO based on the first configuration information, wherein the power of the repeated transmission of the first PRACH preamble code performed across the plurality of first ROs is based on a first reference signal RS for obtaining a path loss value, and Wherein, the transmit power ramp-up is not applied in the plurality of first ROs.

12. A base station for performing communication in a wireless communication system, the base station comprising: at least one transceiver; as well as at least one processor connected to the at least one transceiver, Wherein, the at least one processor is configured to: Sending, through the at least one transceiver, first configuration information related to repeated transmission of a physical random access channel PRACH preamble code to a user equipment UE; and performing repeated reception of a first PRACH preamble code in a plurality of first random access channel opportunities RO based on the first configuration information, wherein the power of the repeated transmission of the first PRACH preamble code performed across the plurality of first ROs is based on a first reference signal RS for obtaining a path loss value, and Wherein, the transmit power ramp-up is not applied in the plurality of first ROs.

13. A processing device configured to control a user equipment UE in a wireless communication system, the processing device comprising: at least one processor; as well as at least one computer memory operatively coupled to the at least one processor and storing instructions for performing operations when executed by the at least one processor; The operations include: receiving first configuration information related to repeated transmission of a physical random access channel PRACH preamble code from a base station; and Based on the first configuration information, repeatedly sending a first PRACH preamble code in multiple first random access channel opportunities RO, wherein the power of the repeated transmission of the first PRACH preamble code performed across the plurality of first ROs is based on a first reference signal RS for obtaining a path loss value, and Wherein, the transmit power ramp-up is not applied in the plurality of first ROs.

14. At least one non-transitory computer-readable medium storing at least one instruction, Based on the at least one instruction being executed by at least one processor, the device for performing communication in the wireless communication system is controlled to: receiving first configuration information related to repeated transmission of a physical random access channel PRACH preamble code from a base station; and Based on the first configuration information, repeatedly sending a first PRACH preamble code in multiple first random access channel opportunities RO, in, The power of the repeated transmission of the first PRACH preamble code performed across the plurality of first ROs is based on a first reference signal RS for obtaining a path loss value, and Wherein, the transmit power ramp-up is not applied in the plurality of first ROs.

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