Uplink channel transmission methods in wireless communication systems and devices that implement this method.

Abstract

The invention proposes a method for performing uplink channel transmission in a wireless communication system, which is performed by a terminal device and comprises the following steps: receiving system information block 1 (SIB1) from the base station; transmitting the initials for the random access procedure to the base station; receiving the random access response (RAR) to the initials from the base station; and transmitting PUSCH to the base station based on the random access response.

Description

Method for transmitting an uplink channel in a wireless communication system and device therefor

[0001] This specification relates to a wireless communication system, and to a method for transmitting an uplink channel and a device therefor.

[0002] Since the commercialization of 4G (4th generation) communication systems, efforts are being made to develop new 5G (5th generation) communication systems to meet the growing demand for wireless data traffic. 5G communication systems are also referred to as "beyond 4G network" communication systems, "post-LTE" systems, or "new radio" (NR) systems. To achieve high data rates, 5G communication systems include systems operating in the ultra-high frequency (mmWave) band above 6 GHz. Furthermore, for coverage purposes, systems operating in frequency bands below 6 GHz are being considered for implementation at base stations and terminals.

[0003] The 3rd Generation Partnership Project (3GPP) NR system improves network spectral efficiency, enabling carriers to provide more data and voice services within a given bandwidth. Therefore, the 3GPP NR system is designed to meet the demands for high-speed data and media transmission in addition to high-capacity voice support. The advantages of the NR system include high throughput, low latency, support for both frequency division duplex (FDD) and time division duplex (TDD) on the same platform, an improved end-user experience, and a simple architecture that reduces operating costs. To further enhance data processing efficiency, the NR system's dynamic TDD can vary the number of orthogonal frequency division multiplexing (OFDM) symbols available for uplink and downlink transmissions based on the data traffic direction of users in the cell. For example, when the cell's downlink traffic exceeds its uplink traffic, the base station can allocate multiple downlink OFDM symbols to a slot (or subframe). Information about the slot configuration must be transmitted to terminals.

[0004] To mitigate the path loss of radio waves in ultra-high frequency bands and increase the transmission distance of radio waves, beamforming, massive MIMO (massive MIMO), full dimensional MIMO (FD-MIMO), array antenna, analog beamforming, hybrid beamforming that combines analog beamforming and digital beamforming, and large scale antenna technologies are being discussed in 5G communication systems. Additionally, to improve the network of the system, 5G communication systems are developing technologies for advanced small cells, advanced small cells, cloud radio access networks (cloud RAN), ultra-dense networks, device to device communication (D2D), vehicle to everything communication (V2X), wireless backhaul, non-terrestrial network communication (NTN), moving networks, cooperative communication, coordinated multi-points (CoMP), and interference cancellation.In addition, advanced coding modulation (ACM) methods such as hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC), as well as advanced access technologies such as filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) are being developed in 5G systems.

[0005] Meanwhile, the Internet is evolving from a human-centric network where humans create and consume information to the Internet of Things (IoT), where information is exchanged and processed between distributed components such as objects. The Internet of Everything (IoE), which combines IoT technologies with big data processing technologies through connections to cloud servers, is also emerging. To implement the IoT, technological elements such as sensing technology, wireless and wired communication and network infrastructure, service interface technology, and security technology are required. Recently, research is being conducted on technologies such as sensor networks, machine-to-machine (M2M) communication, and machine-type communication (MTC) for connecting objects. In the IoT environment, intelligent IT (Internet technology) services can be provided that collect and analyze data generated from connected objects to create new value for human life. Through the convergence and integration of existing IT (Information Technology) technologies with various industries, the IoT can be applied to areas such as smart homes, smart buildings, smart cities, smart or connected cars, smart grids, healthcare, smart appliances, and advanced medical services.

[0006] Accordingly, various attempts are being made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, machine-to-machine (M2M), and machine-type communication (MTC) are being implemented using 5G communication techniques such as beamforming, MIMO, and array antennas. Cloud RAN, a big data processing technology described above, can also be considered an example of the convergence of 5G and IoT technologies. Mobile communication systems have traditionally been developed to provide voice services while ensuring user activity.

[0007] However, mobile communication systems are gradually expanding beyond voice to include data services, and have now evolved to the point where they can provide high-speed data services. However, resource shortages and user demand for high-speed services in existing mobile communication systems are driving the need for more advanced systems.

[0008] The purpose of this specification is to provide a method for transmitting an uplink channel in a wireless communication system and a device therefor.

[0009] The present specification provides a method for transmitting an uplink channel in a wireless communication system and a device therefor.

[0010] Specifically, in a wireless communication system, a method for transmitting an uplink channel comprises the steps of: receiving a System Information Block 1 (SIB1) from a base station; transmitting a preamble for a random access procedure to the base station; receiving a Random Access Response (RAR) to the preamble from the base station, the random access response including information for scheduling a Physical Uplink Shared Channel (PUSCH) transmitted by the terminal to the base station; and transmitting the PUSCH to the base station based on the random access response, wherein the SIB1 includes information on a candidate set of the number of repetitions including values ​​for one or more numbers of repetitions for performing repeated transmission of the PUSCH, and the random access response includes information indicating one of the values ​​for one or more numbers of repetitions included in the candidate set of the number of repetitions, and the PUSCH is characterized in that it is repeatedly transmitted as many as the one or more values.

[0011] A terminal further comprises a step of receiving, from a base station, downlink control information (DCI) including information for scheduling a retransmission PUSCH; a step of repeatedly transmitting, to the base station, the retransmission PUSCH based on the DCI, wherein the information for scheduling the retransmission PUSCH includes information on a number of repetitions of the retransmission PUSCH, and the information on the number of repetitions of the retransmission PUSCH is included in a HARQ process number field of the DCI, wherein the retransmission PUSCH is identical to the PUSCH, and the DCI is characterized in that the base station transmits it when the base station fails to receive the PUSCH transmitted by the terminal.

[0012] In a wireless communication system, a terminal transmitting an uplink channel includes a transceiver; a processor controlling the transceiver, wherein the processor receives a System Information Block 1 (SIB1) from a base station, transmits a preamble for a random access procedure to the base station, and receives a Random Access Response (RAR) to the preamble from the base station, wherein the random access response includes information for scheduling a Physical Uplink Shared Channel (PUSCH) transmitted by the terminal to the base station, and transmits the PUSCH to the base station based on the random access response, wherein the SIB1 includes information on a candidate set of the number of repetitions including values ​​for one or more numbers of repetitions for performing repeated transmission of the PUSCH, and the random access response includes information indicating one of the values ​​for one or more numbers of repetitions included in the candidate set of the number of repetitions, and wherein the PUSCH is repeatedly transmitted as many times as the one or more values.

[0013] The processor receives, from a base station, downlink control information (DCI) including information for scheduling a retransmission PUSCH, and repeatedly transmits the retransmission PUSCH to the base station based on the DCI, the information for scheduling the retransmission PUSCH includes information on the number of repetitions of the retransmission PUSCH, and the information on the number of repetitions of the retransmission PUSCH is included in a HARQ process number field of the DCI, and the retransmission PUSCH is identical to the PUSCH, and the DCI is characterized in that the base station transmits it when the base station fails to receive the PUSCH transmitted by the terminal.

[0014] The above random access response is characterized in that it is a physical downlink shared channel (PDSCH) including an uplink (UL) grant.

[0015] The information indicating any one of the above values ​​is characterized in that it is included in at least one of a Time Domain Resource Assignment (TDRA) field, a Modulation Coding Scheme (MCS) field, and a Transmission Power Control (TPC) field of the random access response.

[0016] When information indicating one of the above values ​​is included in the MCS field, the one of the values ​​is characterized in that it is indicated by one or more MSBs (Most Significant Bits) among the bits of the MCS field.

[0017] When information indicating one of the above values ​​is included in the TPC field, the one of the values ​​is characterized in that it is indicated by one or more LSBs (Least Significant Bits) among the bits of the TPC field.

[0018] The SIB1 includes at least one of information related to the preamble and a RACH opportunity, and the PUSCH is characterized in that it is transmitted on a resource determined based on at least one of information related to the preamble and the RACH opportunity.

[0019] The above DCI is scrambled with TC-RNTI, and the format of the DCI is characterized by being DCI format 0_0.

[0020] Each of the values ​​for the number of repetition transmissions above is characterized in that it is a power of 2.

[0021] Each of the values ​​for the number of repetition transmissions is characterized by being 1, 2, 4 and 8.

[0022] The random access response includes a frequency hopping flag indicating whether the PUSCH frequency hops, and the PUSCH is characterized in that it frequency hops within a slot (intra-slot) or between slots (inter-slot) based on any one of the values ​​and the frequency hopping flag.

[0023] If any one of the above values ​​is 1, and if the value of the frequency hopping flag indicates that the PUSCH frequency hops, the PUSCH frequency hops within a slot, and if the value of the frequency hopping flag indicates that the PUSCH does not frequency hop, the PUSCH does not frequency hop.

[0024] If any one of the above values ​​is greater than 1, and if the value of the frequency hopping flag indicates that the PUSCH frequency hops, the PUSCH frequency hops inter-slot, and if the value of the frequency hopping flag indicates that the PUSCH does not frequency hop, the PUSCH does not frequency hop.

[0025] The random access response further includes information about a resource on which a first repetitive transmission of the PUSCH is performed, and the information about the resource on which the first repetitive transmission of the PUSCH is performed is a slot offset value between a resource on which the random access response is received and a resource on which the first repetitive transmission of the PUSCH is performed, and the SIB1 further includes information related to a TDD (Time Division Duplex) configuration, and the information related to the TDD configuration is information about a type of symbols constituting a slot, and the types of the symbols are any one of a downlink symbol configured to be available for downlink transmission, an uplink symbol configured to be available for uplink transmission, and a flexible symbol that is not configured as the downlink symbol or the uplink symbol, and the PUSCH is repeatedly transmitted in units of slots, and the resource on which the first repetitive transmission of the PUSCH is performed is characterized in that it is a resource that is separated by the slot offset value from a resource on which the random access response is received.

[0026] The resource on which the first repeated transmission of the PUSCH is performed is a flexible slot, and repeated transmissions after the first repeated transmission of the PUSCH are performed on an uplink slot, and the flexible slot is configured to include at least one flexible symbol, and the uplink slot is characterized in that all of the uplink slots are configured with the uplink symbols.

[0027] In a method for receiving an uplink channel in a wireless communication system, the method performed by a base station comprises the steps of: transmitting a System Information Block 1 (SIB1) to a terminal; receiving a preamble for a random access procedure from the terminal; transmitting a Random Access Response (RAR) to the terminal in response to the preamble, the random access response including information for scheduling a Physical Uplink Shared Channel (PUSCH) transmitted by the terminal to the base station; and receiving the PUSCH based on the random access response from the terminal, wherein the SIB1 includes information on a candidate set of the number of repetitions including values ​​for one or more numbers of repetitions for performing repeated transmission of the PUSCH, and the random access response includes information indicating one of the values ​​for one or more numbers of repetitions included in the candidate set of the number of repetitions, and the PUSCH is characterized in that it is repeatedly transmitted as many as the one or more values.

[0028] The purpose of this specification is to provide a method for repeatedly transmitting Msg3 PUSCH of a random access procedure.

[0029] The purpose of this specification is to provide a method for inter-slot frequency hopping of repeatedly transmitted Msg3 PUSCH.

[0030] The purpose of this specification is to provide a method for determining a resource on which Msg3 PUSCH is repeatedly transmitted.

[0031] The effects that can be obtained from this specification are not limited to the effects mentioned above, and other effects that are not mentioned can be clearly understood by those skilled in the art to which the present invention pertains from the description below.

[0032] Figure 1 shows an example of a radio frame structure used in a wireless communication system.

[0033] Figure 2 shows an example of a downlink (DL) / uplink (UL) slot structure in a wireless communication system.

[0034] Figure 3 is a drawing for explaining a physical channel used in a 3GPP system and a general signal transmission method using the physical channel.

[0035] Figures 4a and 4b illustrate SS / PBCH blocks for initial cell access in a 3GPP NR system.

[0036] Figures 5a and 5b illustrate procedures for transmitting control information and control channels in a 3GPP NR system.

[0037] Figure 6 is a diagram showing a CORESET (control resource set) in which a PDCCH (physical downlink control channel) can be transmitted in a 3GPP NR system.

[0038] FIG. 7 is a diagram illustrating a method for setting a PDCCH search space in a 3GPP NR system.

[0039] Figure 8 is a conceptual diagram explaining carrier aggregation.

[0040] Figure 9 is a diagram for explaining single carrier communication and multi-carrier communication.

[0041] Figure 10 is a diagram illustrating an example in which a cross-carrier scheduling technique is applied.

[0042] Figure 11 is a block diagram showing the configuration of a terminal and a base station according to one embodiment of the present invention.

[0043] FIG. 12 illustrates a method for scheduling a physical uplink shared channel in the time domain according to one embodiment of the present invention.

[0044] FIG. 13 illustrates a method for scheduling a physical uplink shared channel in the frequency domain according to one embodiment of the present invention.

[0045] Figure 14 illustrates repeated transmission of a physical uplink shared channel according to one embodiment of the present invention.

[0046] FIG. 15 illustrates a scheduling method of a physical uplink control channel according to one embodiment of the present invention.

[0047] Figure 16 illustrates repeated transmission of a physical uplink control channel according to one embodiment of the present invention.

[0048] FIG. 17 is a diagram illustrating repeated transmission of Msg3 PUSCH according to one embodiment of the present invention.

[0049] FIG. 18 is a diagram illustrating repeated transmission of Msg3 PUSCH using three DMRSs according to one embodiment of the present invention.

[0050] FIGS. 19 to 21 illustrate a Msg3 PUSCH transmission method using two DMRSs according to one embodiment of the present invention.

[0051] FIGS. 22 to 26 illustrate a method for determining the number of modulation symbols for multiplexing uplink control information included in Msg3 PUSCH according to one embodiment of the present invention.

[0052] FIG. 27 and FIG. 28 illustrate resources that can be used for repeated transmission of Msg3 PUSCH according to one embodiment of the present invention.

[0053] FIG. 29 illustrates a method for determining a frequency hopping method according to the number of repeated transmissions of a PUCCH according to one embodiment of the present invention.

[0054] Figure 30 is a flowchart illustrating a method for a terminal to transmit Msg3 PUSCH according to one embodiment of the present invention.

[0055] The terms used in this specification have been selected from widely used and current terms, taking into account the functions of the present invention. However, these terms may vary depending on the intentions of those skilled in the art, customs, or the emergence of new technologies. Furthermore, in certain cases, the applicant may arbitrarily select terms, in which case their meanings will be described in the description of the relevant invention. Therefore, it should be noted that the terms used in this specification should be interpreted based on their substantive meaning and the overall content of this specification, rather than simply their names.

[0056] Throughout the specification, when a component is said to be "connected" to another component, this includes not only the case where the component is "directly connected," but also the case where the component is "electrically connected" with another component intervening therebetween. Furthermore, when a component is said to "include" a particular component, this does not exclude the other component, but rather allows the inclusion of other components, unless specifically stated otherwise. Furthermore, the terms "more than" or "less than" based on a specific threshold may be appropriately replaced with "more than" or "less than", respectively, depending on the embodiment.

[0057] The following technologies can be used in various wireless access systems, such as CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), and SC-FDMA (single carrier frequency division multiple access). CDMA can be implemented with radio technologies such as UTRA (Universal Terrestrial Radio Access) or CDMA2000. TDMA can be implemented with radio technologies such as GSM (Global System for Mobile communications) / GPRS (General Packet Radio Service) / EDGE (Enhanced Data Rates for GSM Evolution). OFDMA can be implemented with radio technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and E-UTRA (Evolved UTRA). UTRA is a part of UMTS (Universal Mobile Telecommunications System). 3GPP (3rd Generation Partnership Project) LTE (long term evolution) is a part of E-UMTS (Evolved UMTS) that uses E-UTRA, and LTE-A (Advanced) is an evolved version of 3GPP LTE.3GPP NR (New Radio) is a system designed separately from LTE / LTE-A to support enhanced Mobile Broadband (eMBB), Ultra-Reliable and Low Latency Communication (URLLC), and massive Machine Type Communication (mMTC) services, which are requirements of IMT-2020. For clarity, the following description focuses on 3GPP NR, but the technical concepts of the present invention are not limited thereto.

[0058] Unless otherwise specified herein, a base station may include a gNB (next generation node B) defined in 3GPP NR. In addition, unless otherwise specified, a terminal may include a UE (user equipment). Hereinafter, to facilitate understanding of the description, each content is described separately as an embodiment, but each embodiment may be used in combination with each other. In the present disclosure, the configuration of a terminal may refer to a configuration by a base station. Specifically, the base station may transmit a channel or signal to the terminal to set the values ​​of parameters used in the operation of the terminal or in a wireless communication system.

[0059] Figure 1 shows an example of a radio frame structure used in a wireless communication system.

[0060] Referring to Figure 1, the radio frame (or radio frame) used in the 3GPP NR system is 10ms (Δf max N f / 100) * T c ) can have a length of . In addition, a radio frame consists of 10 equally sized subframes (SF). Here, Δf max =480*10 3 Hz, N f =4096, T c =1 / (Δfref *N f,ref ), Δf ref =15*10 3 Hz, N f,ref =2048. Each of the 10 subframes within a radio frame can be numbered from 0 to 9. Each subframe has a length of 1ms and can be composed of one or more slots depending on the subcarrier spacing. More specifically, the subcarrier spacing that can be used in the 3GPP NR system is 15*2. μ kHz. μ is the subcarrier spacing configuration, and μ can have a value of 0 to 4. That is, 15 kHz, 30 kHz, 60 kHz, 120 kHz, or 240 kHz can be used as the subcarrier spacing. A 1 ms long subframe is 2 μ It can be composed of slots, where the length of each slot is 2 -μ ms. 2 within one subframe μ The slots of each dog are numbered from 0 to 2 μ - Numbers from 1 to 1 can be assigned. Also, slots within a radio frame are numbered from 0 to 10*2. μ - A number up to 1 may be assigned. Time resources may be distinguished by at least one of a radio frame number (also called a radio frame index), a subframe number (also called a subframe index), and a slot number (or slot index).

[0061] Figure 2 illustrates an example of a downlink (DL) / uplink (UL) slot structure in a wireless communication system. In particular, Figure 2 illustrates the structure of a resource grid of a 3GPP NR system.

[0062] There is one resource grid per antenna port. Referring to Fig. 2, a slot includes multiple OFDM (orthogonal frequency division multiplexing) symbols in the time domain and multiple resource blocks (RBs) in the frequency domain. An OFDM symbol also means one symbol period. Unless otherwise specified, an OFDM symbol may be simply referred to as a symbol. One RB includes 12 consecutive subcarriers in the frequency domain. Referring to Fig. 2, a signal transmitted in each slot is N size,μ grid,x * N RB sc N subcarriers and slot symb It can be expressed as a resource grid consisting of OFDM symbols. Here, when it is a downlink resource grid, x = DL, and when it is an uplink resource grid, x = UL. N size,μ grid,x represents the number of resource blocks (RBs) according to the subcarrier spacing configuration factor μ (x is DL or UL), and N slot symb represents the number of OFDM symbols in a slot. N RB sc N is the number of subcarriers that constitute one RB. RB sc =12. Depending on the multiple access method, an OFDM symbol may be referred to as a CP-OFDM (cyclic prefix OFDM) symbol or a DFT-S-OFDM (discrete Fourier transform spread OFDM) symbol.

[0063] The number of OFDM symbols included in one slot may vary depending on the length of the CP (cyclic prefix). For example, in the case of a normal CP, one slot may include 14 OFDM symbols, but in the case of an extended CP, one slot may include 12 OFDM symbols. In a specific embodiment, the extended CP may be used only at a 60 kHz subcarrier spacing. In Fig. 2, for convenience of explanation, a case in which one slot consists of 14 OFDM symbols is exemplified, but embodiments of the present invention may be applied in the same manner to slots having a different number of OFDM symbols. Referring to Fig. 2, each OFDM symbol is, in the frequency domain, N size,μ grid,x * N RB sc It contains subcarriers. The types of subcarriers can be divided into data subcarriers for data transmission, reference signal subcarriers for reference signal transmission, and guard bands. The carrier frequency is also called the center frequency (fc).

[0064] One RB is N in the frequency domain. RB sc can be defined by a number of consecutive subcarriers (e.g., 12). For reference, a resource consisting of one OFDM symbol and one subcarrier can be referred to as a resource element (RE) or tone. Therefore, one RB is N slot symb * N RB sc It can be composed of resource elements. Each resource element within the resource grid can be uniquely defined by an index pair (k, l) within one slot. k is from 0 to N in the frequency domain. size,μ grid, x * N RBsc - An index is given from 1, and l is from 0 to N in the time domain. slot symb - It can be an index assigned up to 1.

[0065] For a terminal to receive signals from or transmit signals to a base station, its time / frequency synchronization may need to be aligned with that of the base station. Only when the base station and terminal are synchronized can the terminal determine the time and frequency parameters necessary to accurately demodulate DL signals and transmit UL signals.

[0066] Each symbol of a radio frame operating in time division duplex (TDD) or an unpaired spectrum can be composed of at least one of a downlink symbol (DL symbol), an uplink symbol (UL symbol), or a flexible symbol. A radio frame operating as a downlink carrier in frequency division duplex (FDD) or a paired spectrum can be composed of downlink symbols or flexible symbols, and a radio frame operating as an uplink carrier can be composed of uplink symbols or flexible symbols. Downlink transmission is possible in a downlink symbol but uplink transmission is not possible, and uplink transmission is possible in an uplink symbol but downlink transmission is not possible. A flexible symbol can be determined whether to be used for downlink or uplink depending on a signal.

[0067] Information about the type of each symbol, i.e., information indicating either a downlink symbol, an uplink symbol, or a flexible symbol, may be configured as a cell-specific (or common) radio resource control (RRC) signal. In addition, information about the type of each symbol may be additionally configured as a UE-specific (or dedicated) RRC signal. The base station uses the cell-specific RRC signal to indicate i) the period of the cell-specific slot configuration, ii) the number of slots containing only downlink symbols from the beginning of the period of the cell-specific slot configuration, iii) the number of downlink symbols from the first symbol of the slot immediately following the slot containing only downlink symbols, iv) the number of slots containing only uplink symbols from the end of the period of the cell-specific slot configuration, and v) the number of uplink symbols from the last symbol of the slot immediately preceding the slot containing only uplink symbols. Here, a symbol that is not composed of either an uplink symbol or a downlink symbol is a flexible symbol.

[0068] When information about the symbol type is configured as a terminal-specific RRC signal, the base station can signal whether the flexible symbol is a downlink symbol or an uplink symbol using a cell-specific RRC signal. At this time, the terminal-specific RRC signal cannot change the downlink symbol or uplink symbol configured as the cell-specific RRC signal to a different symbol type. The terminal-specific RRC signal is configured for each slot, and N of the corresponding slot slot symb Number of downlink symbols in the symbol slot, N slot symbThe number of uplink symbols in the symbol can be signaled. At this time, the downlink symbols of the slot can be configured continuously from the first symbol of the slot to the i-th symbol. In addition, the uplink symbols of the slot can be configured continuously from the j-th symbol of the slot to the last symbol (where, i <j). 슬롯에서 상향링크 심볼과 하향링크 심볼 어느 것으로도 구성되지 않은 심볼은 플랙서블 심볼이다.

[0069] The type of symbol composed of the above RRC signal can be referred to as a semi-static DL / UL configuration. In the semi-static DL / UL configuration composed of the above RRC signal, a flexible symbol can be indicated as a downlink symbol, an uplink symbol, or a flexible symbol through dynamic SFI (slot format information) transmitted on a physical downlink control channel (PDCCH). In this case, the downlink symbol or uplink symbol composed of the RRC signal is not changed to another symbol type. Table 1 shows examples of dynamic SFI that a base station can indicate to a terminal.

[0070]

[0071] In Table 1, D represents a downlink symbol, U represents an uplink symbol, and X represents a flexible symbol. As shown in Table 1, up to two DL / UL switchings can be allowed within one slot.

[0072] FIG. 3 is a diagram illustrating a physical channel used in a 3GPP system (e.g., NR) and a general signal transmission method using the physical channel.

[0073] When the terminal powers up or enters a new cell, the terminal performs an initial cell search operation (S101). Specifically, the terminal can synchronize with the base station during the initial cell search. To this end, the terminal receives a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) from the base station to synchronize with the base station and obtain information such as a cell index. Thereafter, the terminal can receive a physical broadcast channel from the base station to obtain broadcast information within the cell.

[0074] A terminal that has completed initial cell search can obtain more specific system information than the system information obtained through initial cell search by receiving a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) according to information carried in the PDCCH (S102). The system information received by the terminal here is cell-common system information for the terminal to operate properly in the physical layer of the RRC (Radio Resource Control, RRC), and is referred to as remaining system information or system information block (SIB) 1.

[0075] When a terminal accesses a base station for the first time or there are no radio resources for signal transmission (when the terminal is in RRC_IDLE mode), the terminal can perform a random access process for the base station (steps S103 to S106). First, the terminal transmits a preamble through a physical random access channel (PRACH) (S103), and can receive a random access response (RAR) message for the preamble from the base station through a PDCCH and a corresponding PDSCH (S104). At this time, the preamble in steps S103 and S104 can be described as message 1 (Msg1), and the random access response can be described as a response message or message 2 (Msg2). When a valid random access response is received from the terminal, the terminal transmits data including its identifier, etc. to the base station through the physical uplink shared channel (PUSCH) indicated in the uplink grant transmitted from the base station through the PDCCH or PDSCH (S105). At this time, the data including its identifier, etc. of step S105 and the PUSCH including the data may be described as message 3 (Msg3). In addition, the PUSCH including the data may be described as message 3 PUSCH (Msg3 PUSCH). Next, the terminal waits for reception of the PDCCH as an instruction from the base station for collision resolution. When the terminal successfully receives the PDCCH through its identifier and receives the corresponding PDSCH (S106), the random access process is terminated. At this time, the PDCCH and PDSCH of step S106 may be described as message 4 (Msg 4). During the random access process, the terminal can obtain terminal-specific system information required for the terminal to operate properly at the physical layer and at the RRC layer.When the terminal obtains terminal-specific system information from the RRC layer, the terminal enters RRC connected mode (RRC_CONNECTED mode).

[0076] The RRC layer is used to generate and manage messages for control between terminals and the Radio Access Network (RAN). More specifically, the base station and terminals can perform broadcasting of cell system information required for all terminals in the cell, management of delivery of paging messages, mobility management and handover, terminal measurement reporting and control thereof, terminal capability management, and storage management including base station management in the RRC layer. In general, since the update of a signal transmitted in the RRC layer (hereinafter, “RRC signal”) is longer than the transmission / reception cycle (i.e., transmission time interval, TTI) in the physical layer, the RRC signal can be maintained without change for a long period.

[0077] After the procedure described above, the terminal can perform the general uplink / downlink signal transmission procedure of receiving PDCCH / PDSCH (S107) and transmitting physical uplink shared channel (PUSCH) / physical uplink control channel (PUCCH) (S108). In particular, the terminal can receive downlink control information (DCI) through the PDCCH. The DCI can include control information such as resource allocation information for the terminal. In addition, the format of the DCI can vary depending on the purpose of use. The uplink control information (UCI) that the terminal transmits to the base station through the uplink can include downlink / uplink ACK / NACK signals, channel quality indicator (CQI), precoding matrix index (PMI), rank indicator (RI), etc. Here, the CQI, PMI, and RI can be included in channel state information (CSI). In the case of a 3GPP NR system, the terminal can transmit control information such as the HARQ-ACK and CSI described above through PUSCH and / or PUCCH.

[0078] Figures 4a and 4b illustrate SS / PBCH blocks for initial cell access in a 3GPP NR system.

[0079] When a terminal is powered on or attempts to connect to a new cell, it can acquire time and frequency synchronization with the cell and perform an initial cell search process. During the cell search process, the terminal obtains the physical cell identity N of the cell. cell IDcan be detected. To this end, the terminal can synchronize with the base station by receiving a synchronization signal, such as a primary synchronization signal (PSS) and a secondary synchronization signal (SSS), from the base station. At this time, the terminal can obtain information such as a cell identifier (ID).

[0080] Referring to Fig. 4a, the synchronization signal (SS) will be described in more detail. The synchronization signal can be divided into PSS and SSS. PSS can be used to obtain time domain synchronization such as OFDM symbol synchronization, slot synchronization, and / or frequency domain synchronization. SSS can be used to obtain frame synchronization and cell group ID. Referring to Fig. 4a and Table 2, an SS / PBCH block can be composed of 20 consecutive RBs (= 240 subcarriers) in the frequency axis and 4 consecutive OFDM symbols in the time axis. At this time, in the SS / PBCH block, the PSS is transmitted through the 56th to 182nd subcarriers in the first OFDM symbol, and the SSS is transmitted through the 56th to 182nd subcarriers in the third OFDM symbol. Here, the lowest subcarrier index of the SS / PBCH block is numbered from 0. In the first OFDM symbol where PSS is transmitted, the base station does not transmit signals through the remaining subcarriers, i.e., subcarriers 0 to 55 and 183 to 239. Furthermore, in the third OFDM symbol where SSS is transmitted, the base station does not transmit signals through subcarriers 48 to 55 and 183 to 191. The base station transmits the PBCH (physical broadcast channel) through the remaining REs in the SS / PBCH block, excluding the above signals.

[0081]

[0082] The SS can be grouped into 336 physical-layer cell-identifier groups, each group containing three unique identifiers, such that each physical-layer cell ID is part of only one physical-layer cell-identifier group, for a total of 1008 unique physical-layer cell IDs through a combination of three PSSs and SSSs. Therefore, the physical-layer cell ID N cell ID = 3N (1) ID + N (2) ID An index N in the range 0 to 335 representing a group of physical-layer cell identifiers. (1) ID and an index N from 0 to 2 representing the physical-layer identifier within the physical-layer cell-identifier group. (2) ID can be uniquely defined by. The terminal can detect the PSS to identify one of three unique physical-layer identifiers. In addition, the terminal can detect the SSS to identify one of 336 physical-layer cell IDs associated with the physical-layer identifier. At this time, the sequence d of the PSS PSS (n) is as follows.

[0083]

[0084] Here, And,

[0085] is given as

[0086] Also, the sequence d of SSS SSS (n) is as follows.

[0087]

[0088] Here, And,

[0089] is given as

[0090] A 10ms long radio frame can be divided into two half frames each of 5ms long. Referring to Fig. 4b, the slots in which SS / PBCH blocks are transmitted within each half frame are described. The slots in which SS / PBCH blocks are transmitted can be any one of Cases A, B, C, D, and E. In Case A, the subcarrier spacing is 15kHz, and the starting point of the SS / PBCH block is the {2, 8} + 14*nth symbol. At this time, n can be 0 or 1 for carrier frequencies below 3GHz. In addition, n can be 0, 1, 2, or 3 for carrier frequencies exceeding 3GHz and below 6GHz. In Case B, the subcarrier spacing is 30kHz, and the starting point of the SS / PBCH block is the {4, 8, 16, 20} + 28*nth symbol. At this time, n can be 0 for carrier frequencies below 3GHz. Also, n can be 0, 1 at a carrier frequency exceeding 3 GHz and below 6 GHz. In case C, the subcarrier spacing is 30 kHz, and the starting point of the SS / PBCH block is the {2, 8} + 14*nth symbol. At this time, n can be 0, 1 at a carrier frequency below 3 GHz. Also, n can be 0, 1, 2, 3 at a carrier frequency exceeding 3 GHz and below 6 GHz. In case D, the subcarrier spacing is 120 kHz, and the starting point of the SS / PBCH block is the {4, 8, 16, 20} + 28*nth symbol. At this time, n can be 0, 1, 2, 3, 5, 6, 7, 8, 10, 11, 12, 13, 15, 16, 17, 18 at a carrier frequency above 6 GHz. In Case E, the subcarrier spacing is 240 kHz, and the starting point of the SS / PBCH block is {8, 12, 16, 20, 32, 36, 40, 44} + 56*nth symbol. At this time, n can be 0, 1, 2, 3, 5, 6, 7, or 8 for carrier frequencies above 6 GHz.

[0091] Figures 5a and 5b illustrate a procedure for transmitting control information and a control channel in a 3GPP NR system. Referring to Figure 5a, a base station may add a CRC (cyclic redundancy check) masked (e.g., XOR operation) with a radio network temporary identifier (RNTI) to control information (e.g., downlink control information, DCI) (S202). The base station may scramble the CRC with an RNTI value determined according to the purpose / target of each control information. A common RNTI used by one or more terminals may include at least one of a system information RNTI (SI-RNTI), a paging RNTI (P-RNTI), a random access RNTI (RA-RNTI), and a transmit power control RNTI (TPC-RNTI). In addition, a terminal-specific RNTI may include at least one of a cell temporary RNTI (C-RNTI) and a CS-RNTI. Afterwards, the base station can perform rate matching according to the amount of resource(s) used for PDCCH transmission after performing channel encoding (e.g., polar coding) (S204). Afterwards, the base station can multiplex DCI(s) based on a PDCCH structure based on CCE (control channel element) (S208). In addition, the base station can apply additional processes such as scrambling, modulation (e.g., QPSK), and interleaving (S210) to the multiplexed DCI(s) and then map them to resources to be transmitted. CCE is a basic resource unit for PDCCH, and one CCE can be composed of multiple (e.g., 6) REGs (resource element groups). One REG can be composed of multiple (e.g., 12) REs.The number of CCEs used for a single PDCCH can be defined as an aggregation level. In a 3GPP NR system, aggregation levels of 1, 2, 4, 8, or 16 can be used. Figure 5b is a diagram regarding CCE aggregation levels and PDCCH multiplexing, showing the types of CCE aggregation levels used for a single PDCCH and the CCE(s) transmitted in the control domain accordingly.

[0092] Figure 6 is a diagram showing a CORESET (control resource set) in which a PDCCH (physical downlink control channel) can be transmitted in a 3GPP NR system.

[0093] A CORESET is a time-frequency resource where the PDCCH, a control signal for a terminal, is transmitted. Furthermore, a search space, described below, can be mapped to a single CORESET. Therefore, rather than monitoring the entire frequency band for PDCCH reception, a terminal can monitor the time-frequency domain designated by the CORESET and decode the PDCCH mapped to the CORESET. A base station can configure one or more CORESETs for each cell for the terminal. A CORESET can consist of up to three consecutive symbols along the time axis. Furthermore, a CORESET can be configured in units of six consecutive PRBs along the frequency axis. In the embodiment of FIG. 6, CORESET#1 consists of consecutive PRBs, and CORESET#2 and CORESET#3 consist of non-consecutive PRBs. A CORESET can be located in any symbol within a slot. For example, in the embodiment of FIG. 6, CORESET#1 starts at the first symbol of the slot, CORESET#2 starts at the fifth symbol of the slot, and CORESET#9 starts at the ninth symbol of the slot.

[0094] FIG. 7 is a diagram illustrating a method for setting a PDCCH search space in a 3GPP NR system.

[0095] In order to transmit a PDCCH to a terminal, each CORESET may have at least one search space. In an embodiment of the present invention, the search space is a set of all time-frequency resources (hereinafter, PDCCH candidates) on which the PDCCH of the terminal can be transmitted. The search space may include a common search space that 3GPP NR terminals must commonly search and a terminal-specific or UE-specific search space that a specific terminal must search. In the common search space, a PDCCH that is commonly set for all terminals in a cell belonging to the same base station can be monitored. In addition, a terminal-specific search space may be set for each terminal so that the PDCCH allocated to each terminal can be monitored at different search space locations depending on the terminal. In the case of a terminal-specific search space, the search spaces between terminals may be allocated to partially overlap due to the limited control region to which the PDCCH can be allocated. Monitoring PDCCHs involves blindly decoding PDCCH candidates within the search space. Successful blind decoding is referred to as "successful detection / reception of the PDCCH." Failure to do so is referred to as "non-detection / non-reception of the PDCCH," or "non-successful detection / reception."

[0096] For convenience of explanation, a PDCCH scrambled with a group common (GC) RNTI that one or more terminals already know in order to transmit downlink control information to one or more terminals is referred to as a group common (GC) PDCCH or common PDCCH. In addition, a PDCCH scrambled with a terminal-specific RNTI that a specific terminal already knows in order to transmit uplink scheduling information or downlink scheduling information to a specific terminal is referred to as a terminal-specific PDCCH. The common PDCCH may be included in a common search space, and the terminal-specific PDCCH may be included in either the common search space or the terminal-specific PDCCH.

[0097] The base station can inform each terminal or terminal group of information related to resource allocation of the transmission channel, PCH (paging channel) and DL-SCH (downlink-shared channel) (i.e., DL Grant) or information related to resource allocation of UL-SCH (uplink-shared channel) and HARQ (hybrid automatic repeat request) (i.e., UL Grant) through PDCCH. The base station can transmit PCH transport blocks and DL-SCH transport blocks through PDSCH. The base station can transmit data excluding specific control information or specific service data through PDSCH. In addition, the terminal can receive data excluding specific control information or specific service data through PDSCH.

[0098] The base station can transmit information on the PDCCH, including information about which terminal (one or more terminals) the PDSCH data is transmitted to and how the corresponding terminal should receive and decode the PDSCH data. For example, assume that the DCI transmitted through a specific PDCCH is CRC-masked with an RNTI called "A", and that the DCI indicates that the PDSCH is allocated to a radio resource (e.g., frequency location) called "B", and indicates transmission format information (e.g., transmission block size, modulation method, coding information, etc.) called "C". The terminal monitors the PDCCH using the RNTI information it has. In this case, if there is a terminal that blindly decodes the PDCCH using the "A" RNTI, the terminal receives the PDCCH and, based on the information in the received PDCCH, receives the PDSCH indicated by "B" and "C".

[0099] Table 3 shows an example of a physical uplink control channel (PUCCH) used in a wireless communication system.

[0100]

[0101] PUCCH can be used to transmit the following uplink control information (UCI):

[0102] - SR (Scheduling Request): Information used to request uplink UL-SCH resources.

[0103] - HARQ-ACK: This is a response to the PDCCH (indicating DL SPS release) and / or a response to a downlink transport block (TB) on the PDSCH. HARQ-ACK indicates whether the information transmitted through the PDCCH or PDSCH was successfully received. The HARQ-ACK response includes positive ACK (simply, ACK), negative ACK (hereinafter, NACK), Discontinuous Transmission (DTX), or NACK / DTX. Here, the term HARQ-ACK is used interchangeably with HARQ-ACK / NACK and ACK / NACK. In general, ACK can be expressed with bit value 1, and NACK can be expressed with bit value 0.

[0104] - CSI (Channel State Information): This is feedback information for the downlink channel. It is generated by the terminal based on the CSI-RS (Reference Signal) transmitted by the base station. MIMO (Multiple Input Multiple Output)-related feedback information includes the RI (Rank Indicator) and PMI (Precoding Matrix Indicator). CSI can be divided into CSI Part 1 and CSI Part 2, depending on the information it represents.

[0105] In 3GPP NR systems, five PUCCH formats can be used to support various service scenarios, channel environments, and frame structures.

[0106] PUCCH format 0 is a format that can transmit 1-bit or 2-bit HARQ-ACK information or SR. PUCCH format 0 can be transmitted through 1 or 2 OFDM symbols in the time axis and 1 PRB in the frequency axis. When PUCCH format 0 is transmitted through two OFDM symbols, the same sequence can be transmitted in different RBs in the two symbols. At this time, the sequence can be a sequence cyclically shifted (CS) from the base sequence used in PUCCH format 0. Through this, the terminal can obtain frequency diversity gain. Specifically, the terminal can receive M bit Beat UCI (M bit = 1 or 2) depending on the cyclic shift (CS) value m cs can be determined. In addition, a base sequence of length 12 is given with a CS value m cs A cyclically shifted sequence based on M can be transmitted by mapping it to 12 REs of 1 OFDM symbol and 1 RB. The number of cyclic shifts available to the terminal is 12, and M bit = 1, 1-bit UCI 0 and 1 can be mapped to two cyclically shifted sequences, each with a cyclic shift value difference of 6. In addition, M bit = 2, 2-bit UCI 00, 01, 11, 10 can be mapped to four cyclically shifted sequences, each with a cyclic shift value difference of 3.

[0107] PUCCH format 1 can carry 1-bit or 2-bit HARQ-ACK information or SR. PUCCH format 1 can be transmitted through consecutive OFDM symbols in the time axis and 1 PRB in the frequency axis. Here, the number of OFDM symbols occupied by PUCCH format 1 can be one of 4 to 14. More specifically, M bit= 1 UCI can be modulated with BPSK. The terminal is M bit =2 UCI can be modulated with QPSK (quadrature phase shift keying). A signal is obtained by multiplying a modulated complex valued symbol d(0) by a sequence of length 12. At this time, the sequence may be a base sequence used in PUCCH format 0. The terminal transmits the obtained signal by spreading it with a time-domain OCC (orthogonal cover code) in the even-numbered OFDM symbols to which PUCCH format 1 is assigned. In PUCCH format 1, the maximum number of different terminals multiplexed into the same RB is determined according to the length of the OCC used. A demodulation reference signal (DMRS) can be mapped by spreading it with the OCC in the odd-numbered OFDM symbols of PUCCH format 1.

[0108] PUCCH format 2 can carry UCI exceeding 2 bits. PUCCH format 2 can be transmitted through 1 or 2 OFDM symbols in the time axis and 1 or multiple RBs in the frequency axis. When PUCCH format 2 is transmitted through 2 OFDM symbols, the same sequence can be transmitted through different RBs through the 2 OFDM symbols. Here, the sequence is a plurality of modulated complex symbols d(0), … , d(M symbol -1) can be. Here, M symbol Silver M bit / 2 can be used. This allows the terminal to obtain frequency diversity gain. More specifically, M bit Beat UCI (M bit >2) is bit-level scrambled, QPSK modulated and mapped to RB(s) of one or two OFDM symbol(s), where the number of RB(s) can be between 1 and 16.

[0109] PUCCH format 3 or PUCCH format 4 can carry UCI exceeding 2 bits. PUCCH format 3 or PUCCH format 4 can be transmitted through consecutive OFDM symbols in the time axis and one PRB in the frequency axis. The number of OFDM symbols occupied by PUCCH format 3 or PUCCH format 4 can be one of 4 to 14. Specifically, the terminal can transmit M bit Beat UCI (M bit >2) is modulated with π / 2-BPSK (Binary Phase Shift Keying) or QPSK to produce complex symbols d(0)~d(M symb -1) can be generated. Here, using π / 2-BPSK, M symb =M bit And, if QPSK is used, M symb =M bit / 2. The terminal may not apply block-wise spreading to PUCCH format 3. However, the terminal may apply block-wise spreading to one RB (i.e., 12 subcarriers) using PreDFT-OCC of length 12 so that PUCCH format 4 can have a multiplexing capacity of 2 or 4. The terminal may transmit the spread signal by transmitting precoding (or DFT-precoding) the spread signal and mapping it to each RE.

[0110] At this time, the number of RBs occupied by PUCCH format 2, PUCCH format 3, or PUCCH format 4 can be determined according to the length of UCI transmitted by the terminal and the maximum code rate. If the terminal uses PUCCH format 2, the terminal can transmit HARQ-ACK information and CSI information together through PUCCH. If the number of RBs that the terminal can transmit is greater than the maximum number of RBs available for PUCCH format 2, PUCCH format 3, or PUCCH format 4, the terminal can transmit only the remaining UCI information without transmitting some UCI information according to the priority of the UCI information.

[0111] PUCCH format 1, PUCCH format 3, or PUCCH format 4 can be configured via RRC signaling to indicate frequency hopping within a slot. When frequency hopping is configured, the index of the RB to be frequency hopped can be configured via RRC signaling. When PUCCH format 1, PUCCH format 3, or PUCCH format 4 is transmitted over N OFDM symbols in the time axis, the first hop can have floor(N / 2) OFDM symbols and the second hop can have ceil(N / 2) OFDM symbols.

[0112] PUCCH format 1, PUCCH format 3, or PUCCH format 4 can be configured to be repeatedly transmitted in multiple slots. In this case, the number K of slots in which the PUCCH is repeatedly transmitted can be configured by an RRC signal. The repeatedly transmitted PUCCH must start from the same OFDM symbol in each slot and have the same length. If any OFDM symbol in the slot in which the UE must transmit the PUCCH is indicated as a DL symbol by an RRC signal, the UE may not transmit the PUCCH in that slot and postpone transmission to the next slot.

[0113] Meanwhile, in the 3GPP NR system, a terminal can perform transmission and reception using a bandwidth that is smaller than or equal to the bandwidth of a carrier (or cell). To this end, the terminal can be configured with a bandwidth part (BWP) consisting of a continuous bandwidth of a portion of the carrier's bandwidth. A terminal operating in TDD or an unpaired spectrum can be configured with up to four DL / UL BWP pairs per carrier (or cell). In addition, the terminal can activate one DL / UL BWP pair. A terminal operating in FDD or a paired spectrum can be configured with up to four DL BWPs per downlink carrier (or cell) and up to four UL BWPs per uplink carrier (or cell). The terminal can activate one DL BWP and one UL BWP per carrier (or cell). A terminal may not receive or transmit on time-frequency resources other than the activated BWP. The activated BWP may be referred to as an active BWP.

[0114] A base station can indicate an activated BWP among the configured BWPs of a terminal through downlink control information (DCI). The BWP indicated through the DCI is activated, and other configured BWP(s) are deactivated. In a carrier (or cell) operating in TDD, the base station can include a bandwidth part indicator (BPI) indicating an activated BWP in the DCI scheduling PDSCH or PUSCH to change the DL / UL BWP pair of the terminal. The terminal can receive the DCI scheduling PDSCH or PUSCH and identify the activated DL / UL BWP pair based on the BPI. In a downlink carrier (or cell) operating in FDD, the base station can include a BPI indicating an activated BWP in the DCI scheduling PDSCH to change the DL BWP of the terminal. For an uplink carrier (or cell) operating in FDD, the base station may include a BPI indicating the BWP to be activated in the DCI scheduling the PUSCH to change the UL BWP of the terminal.

[0115] Figure 8 is a conceptual diagram explaining carrier aggregation.

[0116] Carrier aggregation refers to a method in which a wireless communication system utilizes multiple frequency blocks or (logically speaking) cells composed of uplink resources (or component carriers) and / or downlink resources (or component carriers) as a single large logical frequency band, so that the terminal can utilize a wider frequency band. A single component carrier may also be referred to as a PCell (Primary cell), SCell (Secondary Cell), or PScell ​​(Primary SCell). However, for convenience of explanation, the term "component carrier" will be used hereafter.

[0117] Referring to FIG. 8, as an example of a 3GPP NR system, the entire system bandwidth may include up to 16 component carriers, and each component carrier may have a bandwidth of up to 400 MHz. A component carrier may include one or more physically contiguous subcarriers. Although FIG. 8 illustrates that each component carrier has the same bandwidth, this is merely an example, and each component carrier may have a different bandwidth. In addition, although each component carrier is illustrated as being adjacent to each other on the frequency axis, the drawing is illustrated in a logical concept, and each component carrier may be physically adjacent to each other or may be spaced apart from each other.

[0118] Different center frequencies may be used for each component carrier. Furthermore, a common center frequency may be used for physically adjacent component carriers. In the embodiment of FIG. 8, assuming that all component carriers are physically adjacent, center frequency A may be used for all component carriers. Furthermore, assuming that each component carrier is not physically adjacent, center frequency A and center frequency B may be used for each component carrier.

[0119] When the overall system bandwidth is expanded by carrier aggregation, the frequency band used for communication with each terminal can be defined in component carrier units. Terminal A can use the entire system bandwidth of 100 MHz and performs communication using all five component carriers. Terminals B1 to B5 can use only a 20 MHz bandwidth and perform communication using one component carrier. Terminals C1 and C2 can use a 40 MHz bandwidth and perform communication using two component carriers each. The two component carriers may or may not be logically / physically adjacent. The embodiment of FIG. 8 illustrates a case where terminal C1 uses two non-adjacent component carriers and terminal C2 uses two adjacent component carriers.

[0120] Figure 9 is a diagram for explaining single-carrier communication and multi-carrier communication. In particular, Figure 9 (a) illustrates the subframe structure of a single carrier, and Figure 9 (b) illustrates the subframe structure of a multi-carrier.

[0121] Referring to (a) of Fig. 9, a typical wireless communication system can perform data transmission or reception through one DL band and one corresponding UL band in the case of FDD mode. In another specific embodiment, the wireless communication system can divide a radio frame into an uplink time unit and a downlink time unit in the time domain in the case of TDD mode, and perform data transmission or reception through the uplink / downlink time units. Referring to (b) of Fig. 9, three 20MHz component carriers (CCs) each in the UL and DL can be aggregated to support a bandwidth of 60MHz. Each CC can be adjacent or non-adjacent in the frequency domain. For convenience, Fig. 9 (b) illustrates a case where the bandwidth of the UL CC and the bandwidth of the DL CC are both the same and symmetrical, but the bandwidth of each CC can be determined independently. In addition, asymmetric carrier aggregation is also possible, where the number of UL CCs and the number of DL CCs are different. A DL / UL CC allocated / configured to a specific terminal through RRC can be called the serving DL / UL CC of the specific terminal.

[0122] A base station can communicate with a terminal by activating some or all of the serving CCs of the terminal or deactivating some CCs. The base station can change the CCs to be activated / deactivated and the number of CCs to be activated / deactivated. When the base station allocates available CCs to the terminal in a cell-specific or terminal-specific manner, at least one of the assigned CCs may not be deactivated unless the CC allocation to the terminal is completely reconfigured or the terminal performs a handover. One CC that is not deactivated for the terminal is called a primary CC (PCC) or PCell (primary cell), and the CC that the base station can freely activate / deactivate is called a secondary CC (SCC) or SCell (secondary cell).

[0123] Meanwhile, 3GPP NR uses the concept of a cell to manage radio resources. A cell is defined as a combination of downlink and uplink resources, i.e., a combination of a DL CC and an UL CC. A cell can consist of only DL resources or a combination of DL and UL resources. When carrier aggregation is supported, the linkage between the carrier frequency of the DL resources (or DL ​​CC) and the carrier frequency of the UL resources (or UL CC) can be indicated by system information. The carrier frequency refers to the center frequency of each cell or CC. The cell corresponding to the PCC is referred to as a PCell, and the cell corresponding to the SCC is referred to as an SCell. The carrier corresponding to the PCell in the downlink is a DL PCC, and the carrier corresponding to the PCell in the uplink is a UL PCC. Similarly, the carrier corresponding to the SCell in the downlink is a DL SCC, and the carrier corresponding to the SCell in the uplink is a UL SCC. Depending on the UE's capabilities, the serving cell(s) may consist of one PCell and zero or more SCells. For UEs in RRC_CONNECTED state but without carrier aggregation configured or supporting carrier aggregation, there is only one serving cell consisting of only PCell.

[0124] As mentioned above, the term "cell" used in carrier aggregation is distinct from the term "cell" which refers to a certain geographic area where communication services are provided by a single base station or a single antenna group. That is, a single component carrier may also be referred to as a scheduling cell, a scheduled cell, a PCell (Primary cell), a SCell (Secondary Cell), or a PScell ​​(Primary SCell). However, in order to distinguish between a cell referring to a certain geographic area and a cell of carrier aggregation, the present invention refers to a cell of carrier aggregation as a CC, and a cell of a geographic area as a cell.

[0125] FIG. 10 is a diagram illustrating an example of a cross-carrier scheduling technique. When cross-carrier scheduling is configured, a control channel transmitted through a first CC can schedule a data channel transmitted through the first or second CC using a carrier indicator field (CIF). The CIF is included in the DCI. In other words, a scheduling cell is configured, and a DL grant / UL grant transmitted in the PDCCH region of the scheduling cell schedules the PDSCH / PUSCH of the scheduled cell. In other words, a search region for multiple component carriers exists in the PDCCH region of the scheduling cell. The PCell is basically a scheduling cell, and a specific SCell can be designated as a scheduling cell by a higher layer.

[0126] In the embodiment of FIG. 10, it is assumed that three DL CCs are merged. Here, DL component carrier #0 is assumed to be a DL PCC (or PCell), and DL component carrier #1 and DL component carrier #2 are assumed to be DL SCCs (or SCells). In addition, it is assumed that the DL PCC is configured as a PDCCH monitoring CC. If cross-carrier scheduling is not configured by UE-specific (or UE-group-specific or cell-specific) upper layer signaling, CIF is disabled, and each DL CC can transmit only a PDCCH that schedules its own PDSCH without a CIF according to the NR PDCCH rule (non-cross-carrier scheduling, self-carrier scheduling). On the other hand, when cross-carrier scheduling is configured by terminal-specific (or terminal-group-specific or cell-specific) upper layer signaling, CIF is enabled, and a specific CC (e.g., DL PCC) can transmit not only the PDCCH scheduling the PDSCH of DL CC A but also the PDCCH scheduling the PDSCH of other CCs using CIF (cross-carrier scheduling). On the other hand, PDCCH is not transmitted in other DL CCs. Therefore, depending on whether cross-carrier scheduling is configured for the terminal, the terminal monitors the PDCCH that does not include CIF to receive a self-carrier scheduled PDSCH, or monitors the PDCCH that includes CIF to receive a cross-carrier scheduled PDSCH.

[0127] Meanwhile, although FIGS. 9 and 10 illustrate the subframe structure of a 3GPP LTE-A system, the same or similar configuration can also be applied to a 3GPP NR system. However, in a 3GPP NR system, the subframes of FIGS. 9 and 10 can be replaced with slots.

[0128] Figure 11 is a block diagram showing the configuration of a terminal and a base station according to one embodiment of the present invention.

[0129] In embodiments of the present invention, a terminal may be implemented as various types of wireless communication devices or computing devices that ensure portability and mobility. The terminal may be referred to as a UE (User Equipment), STA (Station), MS (Mobile Subscriber), etc. In addition, in embodiments of the present invention, a base station may control and manage cells (e.g., macro cells, femto cells, pico cells, etc.) corresponding to a service area, and perform functions such as signal transmission, channel designation, channel monitoring, self-diagnosis, and relay. The base station may be referred to as a gNB (next generation NodeB) or an AP (access point).

[0130] As illustrated, a terminal (100) according to one embodiment of the present invention may include a processor (110), a communication module (120), a memory (130), a user interface unit (140), and a display unit (150).

[0131] First, the processor (110) can execute various commands or programs and process data within the terminal (100). In addition, the processor (110) can control the overall operation of the terminal (100), including each unit, and control data transmission and reception between the units. Here, the processor (110) can be configured to perform operations according to the embodiments described in the present invention. For example, the processor (110) can receive slot configuration information, determine the slot configuration based on the information, and perform communication according to the determined slot configuration.

[0132] Next, the communication module (120) may be an integrated module that performs wireless communication using a wireless communication network and wireless LAN access using a wireless LAN. To this end, the communication module (120) may be equipped with a plurality of network interface cards (NICs) in built-in or external form, such as a cellular communication interface card (121, 122) and an unlicensed band communication interface card (123). Although the communication module (120) is illustrated as an integrated module in the drawing, each network interface card may be independently arranged depending on the circuit configuration or purpose, unlike the drawing.

[0133] The cellular communication interface card (121) can transmit and receive wireless signals with at least one of a base station (200), an external device, and a server using a mobile communication network, and can provide a cellular communication service by a first frequency band based on a command of the processor (110). According to one embodiment, the cellular communication interface card (121) can include at least one NIC module that uses a frequency band lower than 6 GHz. At least one NIC module of the cellular communication interface card (121) can independently perform cellular communication with at least one of the base station (200), an external device, and a server according to a cellular communication standard or protocol of a frequency band lower than 6 GHz supported by the corresponding NIC module.

[0134] The cellular communication interface card (122) may transmit and receive wireless signals with at least one of a base station (200), an external device, and a server using a mobile communication network, and may provide a cellular communication service by a second frequency band based on a command of the processor (110). According to one embodiment, the cellular communication interface card (122) may include at least one NIC module that uses a frequency band of 6 GHz or higher. At least one NIC module of the cellular communication interface card (122) may independently perform cellular communication with at least one of the base station (200), an external device, and a server according to a cellular communication standard or protocol of a frequency band of 6 GHz or higher supported by the corresponding NIC module.

[0135] The unlicensed band communication interface card (123) transmits and receives wireless signals with at least one of a base station (200), an external device, and a server using the third frequency band, which is an unlicensed band, and provides an unlicensed band communication service based on a command of the processor (110). The unlicensed band communication interface card (123) may include at least one NIC module that uses an unlicensed band. For example, the unlicensed band may be a band of 2.4 GHz, 5 GHz, 6 GHz, 7 GHz, or 52.6 GHz or higher. At least one NIC module of the unlicensed band communication interface card (123) may independently or dependently perform wireless communication with at least one of the base station (200), an external device, and a server according to an unlicensed band communication standard or protocol of a frequency band supported by the corresponding NIC module.

[0136] Next, the memory (130) stores a control program used in the terminal (100) and various data corresponding thereto. This control program may include a predetermined program required for the terminal (100) to perform wireless communication with at least one of a base station (200), an external device, and a server.

[0137] Next, the user interface (140) includes various types of input / output means provided in the terminal (100). That is, the user interface (140) can receive user input using various input means, and the processor (110) can control the terminal (100) based on the received user input. In addition, the user interface (140) can perform output based on a command of the processor (110) using various output means.

[0138] Next, the display unit (150) outputs various images on the display screen. The display unit (150) can output various display objects, such as content executed by the processor (110) or a user interface based on the control commands of the processor (110).

[0139] Additionally, a base station (200) according to one embodiment of the present invention may include a processor (210), a communication module (220), and a memory (230).

[0140] First, the processor (210) can execute various commands or programs and process data within the base station (200). In addition, the processor (210) can control the overall operation of the base station (200), including each unit, and control data transmission and reception between the units. Here, the processor (210) can be configured to perform operations according to the embodiments described in the present invention. For example, the processor (210) can signal slot configuration information and perform communication according to the signaled slot configuration.

[0141] Next, the communication module (220) may be an integrated module that performs wireless communication using a wireless communication network and wireless LAN access using a wireless LAN. To this end, the communication module (220) may be equipped with multiple network interface cards, such as cellular communication interface cards (221, 222) and unlicensed band communication interface cards (223), in built-in or external form. Although the communication module (220) is depicted as an integrated module in the drawing, each network interface card may be independently arranged depending on the circuit configuration or purpose, unlike the drawing.

[0142] The cellular communication interface card (221) can transmit and receive wireless signals with at least one of the terminal (100), external device, and server described above using a mobile communication network, and can provide a cellular communication service using a first frequency band based on a command of the processor (210). According to one embodiment, the cellular communication interface card (221) can include at least one NIC module using a frequency band lower than 6 GHz. At least one NIC module of the cellular communication interface card (221) can independently perform cellular communication with at least one of the terminal (100), external device, and server according to a cellular communication standard or protocol of a frequency band lower than 6 GHz supported by the corresponding NIC module.

[0143] The cellular communication interface card (222) may transmit and receive wireless signals with at least one of a terminal (100), an external device, and a server using a mobile communication network, and may provide a cellular communication service using a second frequency band based on a command of the processor (210). According to one embodiment, the cellular communication interface card (222) may include at least one NIC module using a frequency band of 6 GHz or higher. At least one NIC module of the cellular communication interface card (222) may independently perform cellular communication with at least one of the terminal (100), an external device, and a server according to a cellular communication standard or protocol of a frequency band of 6 GHz or higher supported by the corresponding NIC module.

[0144] The unlicensed band communication interface card (223) transmits and receives wireless signals with at least one of a terminal (100), an external device, and a server using the third frequency band, which is an unlicensed band, and provides an unlicensed band communication service based on a command of the processor (210). The unlicensed band communication interface card (223) may include at least one NIC module that uses an unlicensed band. For example, the unlicensed band may be a band of 2.4 GHz, 5 GHz, 6 GHz, 7 GHz, or 52.6 GHz or higher. At least one NIC module of the unlicensed band communication interface card (223) may independently or dependently perform wireless communication with at least one of the terminal (100), an external device, and a server according to an unlicensed band communication standard or protocol of a frequency band supported by the corresponding NIC module.

[0145] The terminal (100) and base station (200) illustrated in FIG. 11 are block diagrams according to one embodiment of the present invention, and the blocks shown separately are logically distinguished elements of the device. Accordingly, the elements of the above-described device may be mounted as one chip or multiple chips depending on the design of the device. In addition, some components of the terminal (100), such as the user interface (140) and the display unit (150), may be selectively provided in the terminal (100). In addition, the user interface (140) and the display unit (150), etc. may be additionally provided in the base station (200) as needed.

[0146] FIG. 12 illustrates a method for scheduling a physical uplink shared channel in the time domain according to one embodiment of the present invention.

[0147] A terminal can transmit uplink data to a base station via PUSCH. The base station can schedule (PUSCH scheduling) to transmit uplink data to the terminal via PUSCH. i) Using the Dynamic Grant (DG) method, the base station can schedule the PUSCH via DCI included in the PDCCH. Or ii) Using the Configured Grant (CG) method, the terminal can transmit uplink data to the base station via PUSCH according to the resources and transmission method preset by the base station to the terminal.

[0148] At this time, the DCI included in the PDCCH may include PUSCH scheduling information. For example, the DCI may include information on the time domain (time-domain resource assignment, TDRA) and information on the frequency domain (frequency-domain resource assignment, FDRA). The UE may receive the DCI transmitted in the control resource set and search space, and perform operations indicated through the DCI (e.g., uplink data transmission via PUSCH). At this time, the format of the DCI for PUSCH scheduling may be DCI format 0_0, 0_1, 0_2. The DCI of DCI format 0_0, 0_1, 0_2 may be configured to include a TDRA field including time-domain information of the PUSCH. At this time, the time-domain information may include K2, which is an offset value between the slot in which the PDCCH is transmitted from the base station and the slot in which the UE transmits the PUSCH. In addition, DCI may include a Start and Length Indication Value (SLIV), which is a joint-coded value of the start symbol index (S) of the PUSCH and the symbol length (L, number) of the PUSCH within the slot indicated by K2. When the terminal receives DCI in slot n, the slot in which the PUSCH is scheduled is floor(n*2 μPUSCH / n*2 μPDCCH )+K2 slots. μPUSCH and μPDCCH may respectively represent the subcarrier spacing (SCS) of the cell where the PUSCH is scheduled and the cell where the UE receives the PDCCH. floor(x) is a function that returns the largest integer among integers less than or equal to x. In this specification, slot n may represent a slot indexed by index n.

[0149] Referring to Fig. 12(a), the subcarrier spacing (subcarrier spacing) of the cell in which the terminal receives the PDCCH and the cell in which the PUSCH is scheduled may be the same. In this case, if the terminal receives the PDCCH in slot n and K2 is instructed to be 4, the slot in which the PUSCH is scheduled may be slot n+K2, i.e., slot n+4.

[0150] There can be two mapping types for PUSCH scheduling: PUSCH mapping type A and PUSCH mapping type B. Depending on the PUSCH mapping type, the start symbol index of the PUSCH and the range of values ​​that can be SLIV may vary. PUSCH mapping type A can only allocate resources that include a DMRS symbol, and the DMRS symbol can be located in the third or fourth symbol of the slot depending on the value indicated by the upper layer. That is, in the case of PUSCH mapping type A, the index of the start symbol of the PUSCH (S) is 0, and the length of the PUSCH (L) can have one of the values ​​from 4 to 14 (12 in the case of extended CP) depending on the DMRS symbol position. In PUSCH mapping type B, the first symbol of the PUSCH can be the DMRS symbol. Therefore, S can have one of the values ​​from 0 to 13 (11 in the case of extended CP), and L can have one of the values ​​from 1 to 14 (12 in the case of extended CP). Additionally, since a single PUSCH cannot cross the slot boundary, the sum of S and L must be less than or equal to 14 (12 for extended CP).

[0151] Referring to FIG. 12(b), the base station can schedule PUSCH mapping type A in which the third symbol is a DMRS symbol, the index (S) of the start symbol is 0, and the length (L) is 7, PUSCH mapping type A in which the fourth symbol is a DMRS symbol, the index (S) of the start symbol is 0, and the length (L) is 7, and PUSCH mapping type B in which the first symbol is a DMRS symbol, the index (S) of the start symbol is 5, and the length (L) is 5. At this time, the frequency domain information of the PUSCH indicated in the FDRA field of DCI format 0_0, 0_1, 0_2 can be divided into two types according to the frequency resource allocation type.

[0152] FIG. 13 illustrates a method for scheduling a physical uplink shared channel in the frequency domain according to one embodiment of the present invention.

[0153] Referring to Figure 13 below, the frequency resource allocation type is described.

[0154] i) The first type, frequency resource allocation type 0, may be a type that configures an RBG by bundling a certain number of PRBs according to the number of RBs included in the BWP configured (set) for the terminal, and indicates whether to use the RBG through a bitmap per RBG. That is, the terminal can determine whether to use the corresponding RBG through the bitmap transmitted from the base station. The number of PRBs included in one RBG can be set (configured) from a higher layer, and the more RBs included in the BWP configured (configured) for the terminal, the more PRBs can be set (configured). Referring to Fig. 13(a), the BWP size configured (set) for the terminal may be 72 PRBs, and one RBG may be composed of 4 PRBs. At this time, the terminal may determine 4 PRBs as one RBG in ascending order from PRB 0, and each RBG may be indexed from 0. That is, the RBG composed of PRB 0 to PRB 3 can be indexed as RBG 0, and the RBG composed of PRB 4 to PRB 7 can be indexed as RBG 1. In the same way, RBG 17 can be indexed, and at this time, the base station transmits 1 bit (0 or 1) per RBG, a total of 18 bits, to the terminal, and the terminal can determine whether to use the PRB constituting the corresponding RBG based on the received 18 bits. At this time, if the bit value is 0, the terminal can determine that the PUSCH is not scheduled for any PRB among the PRBs constituting the corresponding RBG. If the bit value is 1, the terminal can determine that the PUSCH is scheduled for all PRBs in the corresponding RBG. At this time, the bit values ​​can be applied in reverse. ii) The second type, frequency resource allocation type 1, may be a type that indicates information on consecutive PRBs allocated according to the size of the initial BWP or active BWP of the terminal.Information about consecutive PRBs may be a resource indication value (RIV) value that is combined-coded with the start index (S) and length (L) of consecutive PRBs. Referring to Fig. 13(b), when the BWP size for a UE is 50 PRBs and a PUSCH is scheduled in PRBs 2 through 11 among the 50 PRBs, the start index of the consecutive PRBs may be 2 and the length may be 10. That is, the UE may determine the start index and length of consecutive PRBs for which a PUSCH is scheduled based on the RIV value received from the base station. Specifically, the RIV is N. size BWP *(L-1)+S can be calculated as N size BWP may be the size of the BWP set to the terminal. For example, if the RIV value received by the terminal is 452, it is calculated as 452 = 50*(10-1)+2, so the terminal can determine the start index of the consecutive PRBs for which the PUSCH is scheduled as 2 and the length as 10.

[0155] Through DCI formats 0_1 and 0_2 for scheduling PUSCH, a terminal can be configured by a higher layer to use only one of the two frequency resource allocation types described above, or to dynamically use both types. If a terminal is configured to dynamically use both types, the terminal can determine which type it is by using the most significant bit (MSB) 1 bit of the FDRA field of the DCI.

[0156] There may be an uplink shared channel transmission method based on a configured grant, such as for URLLC transmission. The uplink shared channel transmission method based on the configured grant may be described as grant-free transmission. The uplink shared channel transmission method based on the configured grant may be a method in which, when a base station configures resources available for uplink transmission to a terminal through a higher layer (i.e., RRC signaling), the terminal transmits an uplink shared channel using the configured resources. The uplink shared channel transmission method based on the configured grant may be divided into two types depending on whether the DCI indicates activation and release. i) Type 1: The uplink shared channel transmission method based on the configured grant may be a method in which resources and a transmission method are configured in advance through a higher layer. ii) Type 2: The uplink shared channel transmission method based on the configured grant may be a method in which transmission based on the configured grant is configured through a higher layer, and resources and a method for actual transmission are configured by the DCI.

[0157] An uplink transmission method based on a configured grant can support URLLC transmission. Therefore, in order to ensure high reliability, uplink transmission can be performed repeatedly on multiple slots. At this time, the RV (redundancy version) sequence can be one of {0, 0, 0, 0}, {0, 2, 3, 1}, {0, 3, 0, 3}, and the RV corresponding to the mod(n-1, 4)+1th value can be used in the nth repeated transmission. That is, the RV corresponding to the remainder obtained by dividing n-1 by 4 plus 1 can be used. In addition, a terminal configured to repeatedly transmit an uplink channel can start repeated transmission only in a slot where the RV value corresponds to 0. However, if the RV sequence is {0, 0, 0, 0} and the uplink channel is configured to be repeatedly transmitted in 8 slots, the terminal cannot start repeated transmission in the 8th slot. A terminal can terminate repeated transmissions when the number of repeated transmissions set by the upper layer is reached or the cycle is exceeded, or when a UL grant with the same HARQ process ID is received. The UL grant may refer to a DCI that schedules a PUSCH.

[0158] As described above, in order to improve PUSCH transmission / reception reliability between a base station and a terminal in a wireless communication system, the base station can be configured to repeatedly transmit PUSCH to the terminal.

[0159] Figure 14 illustrates repeated transmission of a physical uplink shared channel according to one embodiment of the present invention.

[0160] There can be two types of PUSCH repetitive transmission performed by a terminal. i) First, PUSCH repetitive transmission type A will be described. When a terminal receives DCI of DCI format 0_1, 0_2 included in a PDCCH for scheduling a PUSCH from a base station, the terminal can repetitively transmit a PUSCH on K consecutive slots. The value of K can be set from a higher layer or can be a value set to the terminal by being included in the TDRA field of the DCI. For example, referring to Fig. 14(a), the terminal can receive a PDCCH for scheduling a PUSCH in slot n, and can set a K2 value from the DCI included in the received PDCCH. In this case, when the K2 value is 2 and the K value is 4, the terminal can start PUSCH repetitive transmission in slot n+K2 and repetitively transmit the PUSCH up to slot n+K2+K-1. That is, the terminal starts PUSCH repetitive transmission at n+2 and repeatedly transmits PUSCH up to n+5. At this time, the resources in the time and frequency domains in which the PUSCH is transmitted in each slot may be the same as those indicated in the DCI. That is, the PUSCH may be transmitted in the same symbol and PRB(s) within the slot. ii) Next, PUSCH repetitive transmission type B is described. PUSCH repetitive transmission type B may be a type used by the terminal to repeatedly transmit a low-latency PUSCH to satisfy requirements of URLLC, etc. The terminal may receive a symbol (S) at which the repetitive transmission of the PUSCH starts and a length (L) of the repetitively transmitted PUSCH through the TDRA field of the DCI transmitted by the base station. At this time, the start symbol (S) and the length (L) may be for a temporarily obtained nominal PUSCH rather than a PUSCH (actual PUSCH) actually transmitted by the terminal. There may be no separate symbols between nominal PUSCHs that are configured to be repeatedly transmitted.That is, nominal PUSCHs can be continuous in the time domain. The UE can determine an actual PUSCH from the nominal PUSCHs. One nominal PUSCH can be determined as one or more actual PUSCHs. The base station can configure the UE with symbols that cannot be used in PUSCH repetition transmission type B. The symbols that cannot be used in PUSCH repetition transmission type B can be described as invalid symbols. The UE can exclude invalid symbols from the resources configured to transmit nominal PUSCHs. As described above, nominal PUSCHs are configured to be repeatedly transmitted on consecutive symbols, but if invalid symbols are excluded, the resources for nominal PUSCH transmission become discontinuous. The actual PUSCH can be configured to be transmitted on consecutive symbols configured for one nominal PUSCH transmission excluding the invalid symbols. In this case, if the consecutive symbols cross the slot boundary, the actual PUSCH that is actually transmitted can be divided based on the slot boundary. An invalid symbol may include a downlink symbol configured by the base station to the terminal. Referring to Fig. 14(b), the terminal may be scheduled for a PUSCH transmission of 5 symbols in length starting from the 12th symbol of the first slot (slot n) and may be configured for 4 Type B repeated transmissions. At this time, the resource scheduled for the first nominal PUSCH (nominal#1) may include symbol (n,11), symbol (n,12), symbol (n,13), symbol (n+1,0), and symbol (n+1,1). The resource scheduled for the second nominal PUSCH (nominal#2) may include symbol (n+1,2), symbol (n+1,3), symbol (n+1,4), symbol (n+1,5), and symbol (n+1,6).The resource scheduled for the third nominal PUSCH (nominal#3) may include symbols (n+1,7), (n+1,8), (n+1,9), (n+1,10), and (n+1,11). The resource scheduled for the fourth nominal PUSCH (nominal#4) may include symbols (n+1,12), (n+1,13), (n+2,0), (n+2,1), and (n+2,2). In this case, symbol (n,k) represents symbol k of slot n. That is, k may be a value from 0 to 13 for normal CP, and a value from 0 to 11 for extended CP. Invalid symbols may be set to symbols 6 and 7 of slot n+1. At this time, to determine the actual PUSCH, the last symbol of the second nominal PUSCH (nominal#2) may be excluded, and the first symbol of the third nominal PUSCH (nominal#3) may be excluded. The first nominal PUSCH (nominal#1) may be divided into two actual PUSCHs (actual#1 and actual#2) that are actually transmitted by the slot boundary. The second nominal PUSCH (nominal#2) and the third nominal PUSCH (nominal#3) may be divided into one actual PUSCH (actual#3 and actual#4) by grouping consecutive symbols excluding invalid symbols. Finally, the fourth nominal PUSCH (nominal#4) is divided into two actual PUSCHs (actual#5 and actual#6) that are actually transmitted by the slot boundary. The terminal ultimately transmits the (actual) PUSCHs that are actually transmitted. One actual PUSCH must include at least one DMRS symbol. Therefore, when PUSCH repetition transmission type B is set, if the total length of the actual PUSCH is one symbol, this actual PUSCH may be omitted without being transmitted.This is because the actual PUSCH, which is a single symbol, cannot contain any information other than DMRS.

[0161] Frequency hopping may be configured for uplink channel transmission to obtain diversity gain in the frequency domain.

[0162] For PUSCH repetitive transmission type A, either intra-slot frequency hopping, in which frequency hopping is performed within a slot, or inter-slot frequency hopping, in which frequency hopping is performed for each slot, may be configured for the UE. When intra-slot frequency hopping is configured for the UE, the UE may divide the PUSCH in half in the time domain in the slot in which the PUSCH is transmitted, and transmit half in the scheduled PRB, and transmit the other half in the PRB obtained by adding an offset value to the scheduled PRB. At this time, the offset value may be configured to two or four values ​​depending on the active BWP size through the upper layer, and one of the values ​​may be configured (instructed) to the UE through DCI. When inter-slot frequency hopping is configured for the UE, the UE may transmit the PUSCH in the PRB scheduled in the slot with an even slot index, and transmit the PUSCH in the PRB obtained by adding an offset value to the scheduled PRB in the odd slot.

[0163] In case of PUSCH repetitive transmission type B, either inter-repetition frequency hopping, in which frequency hopping is performed at the nominal PUSCH boundary, or inter-slot frequency hopping, in which frequency hopping is performed at every slot, may be configured for the UE. When inter-repetition frequency hopping is configured for the UE, the UE transmits actual PUSCH(s) corresponding to odd-numbered nominal PUSCHs on a scheduled PRB, and the UE transmits actual PUSCH(s) corresponding to even-numbered nominal PUSCHs on a PRB obtained by adding an offset value to the scheduled PRB. In this case, the offset value may be configured to two or four values ​​depending on the active BWP size through a higher layer, and one of the values ​​may be configured (instructed) to the UE through DCI. When inter-slot frequency hopping is set for a terminal, the terminal can transmit a PUSCH in a PRB scheduled in a slot with an even slot index, and transmit a PUSCH in a PRB with an offset value added to the PRB scheduled in an odd slot.

[0164] When a terminal performs repeated PUSCH transmission, if a symbol scheduled for PUSCH transmission in a specific slot overlaps with a symbol configured for reception of a semi-statically configured DL symbol or SS / PBCH block, the terminal may not transmit the overlapping PUSCH in the slot containing the overlapping symbol. In addition, the overlapping PUSCH may be postponed and not transmitted in the next slot.

[0165] When a terminal receives a DCI of DCI format 1_0, 1_1, 1_2 for scheduling a PUCCH, the terminal must transmit the PUCCH to the base station. At this time, the PUCCH may include uplink control information (UCI), and the UCI may include at least one of HARQ-ACK, SR (Scheduling Request), and CSI (Channel State Information). The HARQ-ACK may be an HARQ-ACK indicating whether the terminal has successfully received two types of channels. The first type may be a HARQ-ACK for a PDSCH when the terminal schedules a PDSCH through a DCI of DCI format 1_0, 1_1, 1_2. The second type may be HARQ-ACK for DCI when DCI of DCI format 1_0, 1_1, 1_2 is a DCI indicating release of PDSCH that is semi-persistently scheduled (Semi-Persistent Scheduling, SPS). For transmission of PUCCH including HARQ-ACK, the 'PDSCH-to-HARQ_feedback timing indicator' field of DCI may indicate K1, which is information (value) about a slot in which the scheduled PUCCH is transmitted. Here, K1 may be a non-negative integer value. DCI of DCI format 1_0 may indicate one of {0, 1, 2, 3, 4, 5, 6, 7} as the K1 value. The K1 value that can be indicated in DCI of DCI format 1_1, 1_2 may be set (configured) from a higher layer.

[0166] A method for determining a slot for transmitting a PUCCH including a first type of HARQ-ACK is described. There may be an uplink slot that overlaps with the last symbol for transmitting a PDSCH corresponding to the HARQ-ACK. In this case, if the index of the overlapping uplink slot is m, the terminal can transmit a PUCCH including the HARQ-ACK on slot m+K1. The index of the uplink slot may be a value determined based on the subcarrier spacing of the BWP for transmitting the PUCCH. When the terminal is configured for downlink slot aggregation, the last symbol for transmitting the PDSCH may mean the last symbol scheduled within the last slot among the slots for transmitting the PDSCH.

[0167] FIG. 15 illustrates a scheduling method of a physical uplink control channel according to one embodiment of the present invention.

[0168] Referring to FIG. 15, the subcarrier spacing of the DL BWP where the PDCCH is received, the subcarrier spacing of the DL BWP where the PDSCH is scheduled, and the subcarrier spacing of the UL BWP where the PUCCH is transmitted may be the same. The terminal may receive the PDCCH that schedules the PDSCH and the PUCCH from the base station in slot n. At this time, the DCI included in the PDCCH received in slot n may set (indicate) the K0 value to 2 and the K1 value to 3. For example, if the last symbol on which the PDSCH is transmitted is n+K0 (i.e., n+2), the terminal may transmit the HARQ-ACK for the PDSCH on slot n+2+K1 (i.e., n+5). At this time, the HARQ-ACK for the PDSCH may be included in the PUCCH.

[0169] Figure 16 illustrates repeated transmission of a physical uplink control channel according to one embodiment of the present invention.

[0170] In order to secure wide coverage in the NR system, the terminal can repeatedly transmit long PUCCH on 2, 4, or 8 slots. At this time, the long PUCCH format can be PUCCH format 1, 3, or 4. When the terminal repeatedly transmits PUCCH, the same UCI can be repeatedly transmitted in each slot. Referring to Fig. 16, when PDSCH reception is terminated in slot n and the value of K1 is 2, the terminal can transmit PUCCH on slot n+K1 (i.e., n+2). The base station sets the number of repeated PUCCH transmissions to 4(N repeat PUCCH =4), the terminal can repeatedly transmit PUCCH from slot n+2 to slot n+5. At this time, the symbol configuration of the repeatedly transmitted PUCCHs can be the same. That is, the repeatedly transmitted PUCCHs can start from the same symbol of each slot and be composed of the same number of symbols.

[0171] Even for PUCCH transmission, frequency hopping may be applied to obtain diversity gain in the frequency domain. When intra-slot frequency hopping is applied, the terminal may divide the time domain of the slot transmitting the PUCCH in half, transmit the PUCCH on the first PRB in half, and transmit the PUCCH on the second PRB in the other half. The first PRB and the second PRB may be configured through an upper layer that configures PUCCH resources. When inter-slot frequency hopping is applied, the terminal may transmit the PUCCH on the first PRB of a slot whose slot index is even, and transmit the PUCCH on the second PRB of a slot whose slot index is odd. In addition, when performing repeated PUCCH transmission, if the symbols of a specific slot scheduled for PUCCH transmission overlap with symbols configured for reception of semi-statically configured DL symbols or SS / PBCH blocks, the terminal may not transmit the PUCCH on the slot containing the overlapping symbols. A terminal may postpone transmission of an untransmitted PUCCH to the next slot. At this time, if the symbol for PUCCH transmission in the postponed slot does not overlap with the symbol configured for reception of a semi-statically configured DL symbol or SS / PBCH block, the terminal may transmit the PUCCH.

[0172] The present invention proposes a method for solving a coverage problem related to PUSCH transmission performed by a terminal when a random access process is performed between a terminal and a base station.

[0173] As described above with reference to FIG. 3, in the random access process, the terminal can transmit the Msg3 PUSCH through the uplink grant (UL grant) included in the random access response (RAR, Msg2). At this time, the UL grant is information for scheduling the Msg3 PUSCH, and may include a frequency hopping flag indicating frequency hopping information, time domain resource assignment (TDRA) information, frequency domain resource assignment (FDRA) information, modulation and coding scheme (MCS) information, Transmit Power Control (TPC) command information for PUSCH transmission, CSI request information, ChannelAccess-CPext information, etc. The Msg3 PUSCH transmitted through the uplink grant included in Msg2 may be an initial transmission PUSCH. Meanwhile, if the base station fails to receive the Msg3 PUSCH from the terminal, the base station may instruct the terminal to retransmit the Msg3 PUSCH. The retransmission of the Msg3 PUSCH may be instructed (scheduled) by the PDCCH, and at this time, the retransmission may be instructed by a DCI of DCI format 0_0 scrambled with a Temporary C-RNTI (TC-RNTI) included in the PDCCH. The terminal may obtain the TC-RNTI through the previously received random access response (Msg2). If the terminal successfully detects the DCI instructing retransmission, the terminal may retransmit the Msg3 PUSCH based on the information included in the DCI.At this time, the information included in the DCI may be a frequency hopping flag, TDRA information, FDRA information, MCS information, TPC information, ChannelAccess-CPext information, New data indicator (NDI) information, Redundancy version (RV) information, HARQ process number (HPN) information, padding bits information, UL / SUL indicator information, etc. The Msg3 PUSCH indicated through the DCI with DCI format 0_0 may be a retransmission PUSCH.

[0174] In other words, the Msg3 PUSCH described in the present invention may be an initial transmission PUSCH or a retransmission PUSCH. Specifically, the PUSCH indicated through the uplink grant of the random access response (Msg2) may be for initial transmission, and the PUSCH indicated through the DCI in the DCI format 0_0 scrambled with TC-RNTI may be for retransmission.

[0175] Previously, the initial transmission PUSCH and retransmission PUSCH could only be transmitted in a single slot. At this time, a single slot could be indicated by the TDRA field of the uplink grant or the TDRA field of the DCI in DCI format 0_0. In other words, repeated transmission of the Msg3 PUSCH was not possible. Therefore, if the UE fails to receive the PDCCH scheduling Msg4 from the base station within a set period of time after transmitting the Msg3 PUSCH, the UE must determine that the random access process has failed and must restart the random access process from the beginning. For example, if the channel environment is poor, the base station may fail to receive the Msg3 PUSCH even if the UE transmits it. Therefore, the base station cannot transmit the PDCCH scheduling Msg4 to the UE, and the random access process must be restarted. In other words, the coverage of the Msg3 PUSCH may be low. Consequently, the entire random access process may be delayed. Therefore, the present invention describes a method for solving the coverage problem of Msg3 PUSCH through repeated transmission of Msg3 PUSCH.

[0176] The base station can configure to the terminal whether or not the Msg3 PUSCH can be repeatedly transmitted during the random access process. For example, the base station can configure to the terminal whether or not the Msg3 PUSCH can be repeatedly transmitted through the System Information Block 1 (SIB1) transmitted from the base station to the terminal during the cell initial access process. That is, the terminal can check whether or not the Msg3 PUSCH can be repeatedly transmitted through SIB1. Whether or not the Msg3 PUSCH can be repeatedly transmitted can be configured not only through SIB1 but also through other SIBs. That is, whether or not the Msg3 PUSCH can be repeatedly transmitted can be configured through SIBx (x = 1, 2, 3 ...). In addition, whether or not the Msg3 PUSCH can be repeatedly transmitted can be indicated through another channel. For example, the base station can configure whether or not the Msg3 PUSCH can be repeatedly transmitted through the PBCH. Specifically, whether or not to repeatedly transmit Msg3 PUSCH can be set through some bits of PBCH, or whether or not to repeatedly transmit Msg3 PUSCH can be inferred through the DMRS sequence or CRC of PBCH.

[0177] Whether repeated transmission of Msg3 PUSCH is possible can be explicitly indicated or inferred from other information included in SIB1. For example, if SIB1 includes parameters for repeated transmission of Msg3 PUSCH, the UE can determine that repeated transmission of Msg3 PUSCH is possible without a separate configuration (indication) as to whether repeated transmission of Msg3 PUSCH is possible. Conversely, if SIB1 does not include parameters for repeated transmission of Msg3 PUSCH, the UE can determine that repeated transmission of Msg3 PUSCH is not possible without a separate configuration (indication) as to whether repeated transmission of Msg3 PUSCH is possible. In this case, the parameters for repeated transmission of Msg3 PUSCH may indicate a PRACH resource on which repeated transmission of Msg3 PUSCH is performed and the number of times repeated transmission of Msg3 PUSCH is performed. For example, if a terminal is configured with a PRACH resource through SIB1, the terminal can repeatedly transmit Msg3 PUSCH through the configured PRACH resource. In addition, if the terminal is configured with a number of repeated transmissions of Msg3 PUSCH through SIB1, the terminal can transmit Msg PUSCH as many times as the configured number of repeated transmissions. At this time, the base station can set a single value or multiple values ​​as the number of times that Msg3 PUSCH can be repeatedly transmitted to the terminal. For example, the base station can set one value among 1, 2, 4, and 8 to the terminal, or a set including multiple values ​​(e.g., {1, 2, 4, 8}). That is, the base station can set one value as the number of repeated transmissions of Msg3 PUSCH to the terminal, or set multiple values ​​as the number of repeated transmissions. If the base station sets multiple values, the base station can indicate one of the multiple values ​​to the terminal through additional signaling (configuration), etc. If the Msg3 PUSCH transmitted by the terminal is repeatedly transmitted, the Msg3 PUSCH may be repeatedly transmitted in slot units.For example, if the number of repetitions of Msg3 PUSCH is 4, Msg3 PUSCH can be repeatedly transmitted on 4 slots. That is, Msg3 PUSCH transmitted on 1 slot can be repeated 4 times.

[0178] When repeated transmission of Msg3 PUSCH is enabled via SIB1, methods for determining whether a terminal will actually perform repeated transmission of Msg3 PUSCH are described. Furthermore, the meaning of "interpreted by the terminal" described herein may be identical to the meaning of "configured by the base station" to the terminal. Furthermore, the meaning of "configured" described herein may be identical to the meaning of "instructed."

[0179] Method for determining whether to repeat transmission of Msg3 PUSCH of a terminal

[0180] If the base station enables the repeated transmission of Msg3 PUSCH within the cell to the terminal, the terminal can always recognize that the Msg3 PUSCH is repeatedly transmitted even without additional signaling (configuration) from the base station instructing the actual repeated transmission of Msg3 PUSCH.

[0181] i) The terminal can determine whether to repeatedly transmit Msg3 PUSCH based on explicit information received from the base station. Explicit information that allows the terminal to determine whether to repeatedly transmit Msg3 PUSCH may be as follows.

[0182] ia) Information configured from upper layers: The terminal can interpret the information configured from upper layers to determine whether to repeatedly transmit Msg3 PUSCH. For example, the base station can configure whether repeated transmission of Msg3 PUSCH is possible within the cell through SIB1 during the initial cell access process. In addition, if repeated transmission of Msg3 PUSCH is configured as possible, the base station can configure the terminal to always repeatedly transmit Msg3 PUSCH.

[0183] ib) Information in the downlink channel scheduling Msg3 PUSCH: The UE can interpret information in the downlink channel scheduling Msg3 PUSCH to determine whether to repeatedly transmit Msg3 PUSCH. At this time, the downlink channel may include an uplink grant of a random access response, a DCI in DCI format 1_0 for scheduling a random access response, or a DCI in DCI format 0_0 for scheduling Msg3 PUSCH. Specifically, the UE can interpret field information in the uplink grant of the random access response for scheduling the initial transmission of Msg3 PUSCH to determine whether to repeatedly transmit Msg3 PUSCH. The UE can interpret field information in the DCI in DCI format 0_0 scrambled with TC-RNTI for scheduling retransmission of Msg3 PUSCH to determine whether to repeatedly transmit Msg3 PUSCH. The terminal can determine whether to repeatedly transmit Msg3 PUSCH by interpreting the field information in the DCI of DCI format 1_0 that schedules the random access response. At this time, whether to repeatedly transmit Msg3 PUSCH can be indicated using 1 bit in the information included in each downlink channel (i.e., uplink grant, DCI of DCI format 1_0, DCI of DCI format 0_0), and the terminal can determine whether to repeatedly transmit Msg3 PUSCH based on whether to repeatedly transmit PUSCH indicated by the 1 bit.

[0184] ii) The terminal can determine whether to repeatedly transmit Msg3 PUSCH based on implicit information transmitted by the base station. The implicit information that allows the terminal to determine whether to repeatedly transmit Msg3 PUSCH may be as follows.

[0185] The UE can determine whether to repeatedly transmit the Msg3 PUSCH by reinterpreting the information in the downlink channel that schedules the Msg3 PUSCH. For example, ii-a) the UE can determine whether to repeatedly transmit the Msg3 PUSCH by reinterpreting the field information in the uplink grant that schedules the initial transmission of the Msg3 PUSCH. ii-b) the UE can determine whether to repeatedly transmit the Msg3 PUSCH by reinterpreting the field information in the DCI format 0_0 scrambled with TC-RNTI that schedules the retransmission of the Msg3 PUSCH. In this case, the field in ii-a) and ii-b) may be any one of the TDRA, FDRA, MCS, and TPC fields. In this case, the method of interpreting the field may be as follows.

[0186] The terminal can determine whether to reinterpret the field based on the number of symbols scheduled in the TDRA field. For example, if the number of symbols scheduled in the TDRA field is greater than or equal to a certain number, the terminal can reinterpret the field information in the uplink grant of the random access response to determine whether to repeatedly transmit the Msg3 PUSCH. Since the base station allocates a large number of symbols to the terminal with insufficient coverage, if the number of allocated symbols is greater than or equal to a preset specific number, the terminal can repeatedly transmit the Msg3 PUSCH to resolve the coverage issue. In other words, if the number of allocated symbols is less than a preset specific number, the terminal may not perform repeated transmission of the Msg PUSCH. As another example, if the number of symbols scheduled in the TDRA field is less than or equal to a certain number, the terminal can reinterpret the field information in the uplink grant of the random access response to determine whether to repeatedly transmit the Msg3 PUSCH. This is because if the base station allocates a small number of symbols to the terminal, a coverage issue may occur. That is, if the base station allocates more than a certain number of symbols, the terminal may not perform repeated transmissions of the Msg3 PUSCH. In this case, the specific number may be set by a higher layer. The higher layer may refer to SIB1 or other SIBs.

[0187] Based on the number of PRBs scheduled by the FDRA field, the UE can reinterpret the FDRA field to determine whether to repeatedly transmit the Msg3 PUSCH. For example, if the number of PRBs indicated by the FDRA field is greater than or equal to a specific number, the UE can reinterpret the field information in the uplink grant of the random access response to determine whether to repeatedly transmit the Msg3 PUSCH. Since the base station allocates a large number of PRBs to UEs with insufficient coverage, if the number of allocated PRBs is greater than or equal to a preset specific number, the UE can repeatedly transmit the Msg3 PUSCH to resolve the coverage issue. That is, if the number of allocated PRBs is less than or equal to a preset specific number, the UE may not perform repeated transmission of the Msg PUSCH. As another example, if the number of PRBs indicated by the FDRA field is less than or equal to a specific number, the UE can reinterpret the field information in the uplink grant of the random access response to determine whether to repeatedly transmit the Msg3 PUSCH. This is because coverage issues may arise if the base station allocates a small number of PRBs to a UE. Specifically, if the base station allocates more than a specific number of PRBs to a UE, the UE may not perform repeated transmissions of the Msg3 PUSCH. This specific number can be set by a higher layer. The higher layer may refer to SIB1 or other SIBs.

[0188] Depending on the modulation scheme or coding rate indicated by the MCS field, the UE can reinterpret the field to determine whether to transmit the Msg3 PUSCH. For example, if the modulation scheme indicated by the MCS field is low (e.g., QPSK) or the coding rate is low, the UE can reinterpret the field information in the uplink grant of the random access response to determine whether to repeatedly transmit the Msg3 PUSCH. Since the base station sets a low modulation scheme or low coding rate to a UE with insufficient coverage, the UE can perform repeated transmission of the Msg3 PUSCH if the modulation scheme or coding rate is low.

[0189] Tables 4 and 5 show modulation methods and coding rates that can be set for terminals. The modulation order in Tables 4 and 5 refers to the modulation method. If the modulation order is q, it can refer to pi / 2-BPSK (q=1) or QPSK (q=2), if it is 2, it can refer to QPSK, if it is 4, it can refer to 16 QAM, if it is 6, it can refer to 64 QAM, and if it is 8, it can refer to 256 QAM.

[0190]

[0191]

[0192] When transform precoding for PUSCH transmission of the terminal is set to disable, Table 4 may be applied, and when it is set to enable, Table 5 may be applied. When the terminal is scheduled for the initial transmission of Msg3 PUSCH (i.e., when transmission of Msg3 PUSCH is set with an uplink grant of a random access response), the base station may set the first 16 MCS indices (0 to 15) of Table 4 and / or Table 5. For example, referring to Table 4, the base station may set QPSK, 16QAM, and 64QAM as modulation schemes for the terminal, and referring to Table 5, the base station may set pi / 2-BPSK, QPSK, 16QAM, and 64QAM as modulation schemes for the terminal. Among the modulation schemes, the lower modulation scheme may be pi / 2-BPSK or QPSK. That is, when the terminal is set to pi / 2-BPSK or QPSK, the terminal can perform repeated transmission of Msg3 PUSCH.

[0193] Based on the TPC command indicated by the TPC field, the terminal can reinterpret the field to determine whether to perform repeated transmission of the Msg3 PUSCH. For example, if the TPC command indicated by the TPC field indicates a value greater than or equal to a specific value, the terminal can reinterpret the field information in the uplink grant of the random access response to determine whether to perform repeated transmission of the Msg3 PUSCH. Since the base station can indicate a TPC command with a high value (greater than or equal to a specific value) in order to transmit at high power to a terminal with insufficient coverage, if the terminal receives a TPC command greater than or equal to a specific value, the terminal can perform repeated transmission of the Msg3 PUSCH. That is, if the base station sets the TPC command to the terminal to be less than or equal to a specific value, the terminal may not perform repeated transmission of the Msg3 PUSCH.

[0194] Based on the TB size, the UE can reinterpret a specific field to determine whether to perform repeated transmission of the Msg3 PUSCH. The UE can determine the TB size of the Msg3 PUSCH based on the FDRA field, TDRA field, MCS field, etc., and determine whether to perform repeated transmission of the Msg3 PUSCH based on the TB size. For example, if the TB size is less than a certain value, the UE can reinterpret the field information in the uplink grant of the random access response to determine whether to perform repeated transmission of the Msg3 PUSCH. Since the base station can allocate a TB with a small size (less than a certain value) to a UE with insufficient coverage, the UE can perform repeated transmission of the Msg3 PUSCH if the TB is allocated less than a certain value. In other words, the UE may not perform repeated transmission of the Msg3 PUSCH if the TB is allocated greater than a certain value.

[0195] Below, the methods for determining the number of repeated transmissions of Msg3 PUSCH by the terminal are described.

[0196] How to determine the number of repeated transmissions of Msg3 PUSCH

[0197] The terminal can determine the number of repetition transmissions of the Msg PUSCH according to the number of repetition transmissions set by the base station. And the terminal can perform repeated transmission of the Msg3 PUSCH according to the set number of repetition transmissions. Before indicating the number of repetition transmissions, the base station can set multiple candidates for the number of repetition transmissions to the terminal. The candidates for the number of repetition transmissions can be preset values, set as broadcast information, or set in a higher layer. For example, the candidates for the number of repetition transmissions can be configured as {N1, N2, N3, N4 ...}. In this case, the candidates for the number of repetition transmissions (N1, N2, N3, N4 ...) can be natural numbers greater than or equal to 1 and powers of 2. For example, the candidates for the number of repetition transmissions can be {1, 2, 4, 8}. And the terminal can repeatedly transmit the Msg3 PUSCH as many times as any one of the values ​​of 1, 2, 4, and 8 indicated by the base station.

[0198] i) The terminal can receive the number of repeated transmissions of Msg3 PUSCH from the upper layer. For example, if the terminal receives an integer value n as the number of repeated transmissions of Msg3 PUSCH from the upper layer, the terminal can repeatedly transmit Msg3 PUSCH n times.

[0199] ii) The base station can set the number of repeated transmissions of Msg3 PUSCH to the terminal by using the field of DCI of DCI format 0_0 for scheduling Msg3 PUSCH or DCI of DCI format 1_0 for scheduling random access response (Msg2). For example, the terminal can interpret a certain number of bits in DCI of DCI format 1_0 scrambled with RA-RNTI for scheduling random access response as bits indicating the number of repeated transmissions of Msg3 PUSCH and perform repeated transmissions of Msg3 PUSCH. As another example, the terminal can interpret a certain number of bits in DCI of DCI format 0_0 scrambled with TC-RNTI for scheduling retransmission of Msg3 PUSCH as bits indicating the number of repeated transmissions of Msg3 PUSCH and perform repeated transmissions of Msg3 PUSCH.

[0200] At this time, the number of repeated transmissions that can be indicated i) from the upper layer or ii) in DCI format 0_0, 1_0 may be one of multiple candidates for the number of repeated transmissions. Thereafter, the terminal may repeatedly transmit the Msg3 PUSCH as many times as the indicated one value.

[0201] Fields including a certain number of bits in the DCI format 0_0 scrambled with the TC-RNTI of the above ii) may be NDI (New data indicator), HPN (HARQ process number), CSI request, FDRA, and TPC fields. Since the NDI, HPN, and CSI request fields may not be used for Msg3 PUSCH transmission, the terminal may interpret the values ​​of the NDI, HPN, and CSI request fields as field values ​​for repeated transmission of Msg3 PUSCH.

[0202] For UEs with insufficient coverage, the base station can schedule PUSCHs with a small number of PRBs in the frequency domain or with the highest possible transmit power. Accordingly, the UE can interpret a certain number of bits in the FDRA field as field values ​​for repeated transmission of the Msg3 PUSCH, or interpret some of the indices indicating low dB values ​​in the TPC field as field values ​​for repeated transmission of the Msg3 PUSCH.

[0203] The following describes a method for a terminal to interpret a certain number of bits in a DCI format 0_0 scrambled with TC-RNTI for repeated transmission of Msg3 PUSCH. In the following, the candidate numbers of repeated transmissions of Msg PUSCH set to the terminal may be {N1, N2, N3, N4}.

[0204] The terminal can interpret the bit value of one of the fields of the DCI format 0_0 scrambled with TC-RNTI as the number of repeated transmissions of the Msg3 PUSCH. That is, the terminal can interpret X bits of any one of the NDI, HPN, CSI request, FDRA, and TPC fields as a field value for repeated transmissions of the Msg3 PUSCH. For example, the terminal can interpret X (e.g., 2) bits of the HPN field as a field value for repeated transmissions of the Msg3 PUSCH. In this case, the base station can indicate one of four numbers of repeated transmissions (N1, N2, N3, N4) using 2 bits. For example, {00}=N1, {01}=N2, {10}=N3, {11}=N4 can be set.

[0205] The terminal can interpret a combination of bit values ​​of two different fields among the fields of the DCI format 0_0 scrambled with TC-RNTI as the number of repeated transmissions of the Msg3 PUSCH. That is, the terminal can interpret X bits of any one of the NDI, HPN, CSI request, FDRA, and TPC fields and Y bits of any one of the NDI, HPN, CSI request, FDRA, and TPC fields other than the field containing X bits as a field value for repeated transmission of the Msg3 PUSCH. For example, the terminal can interpret a combination of X (e.g., 1) bits of the NDI field and Y (e.g., 1) bits of the HPN field, that is, 2 bits, as a field value for repeated transmission of the Msg3 PUSCH. In this case, the base station can indicate any one of four candidates for the number of repeated transmissions using the 2 bits. For example, {NDI, HPN} may be {0, 0}=N1, {0, 1}=N2, {1, 0}=N3, {1, 1}=N4. Alternatively, {HPN, NDI} may be {0, 0}=N1, {0, 1}=N2, {1, 0}=N3, {1, 1}=N4. As another example, the terminal may interpret the combination of the X (e.g., 1) bit of the NDI field and the Y (e.g., 1) bit of the CSI request field, that is, 2 bits, as a field value for repeated transmission of Msg3 PUSCH. At this time, if the candidates for the number of repeated transmissions of Msg3 PUSCH set to the terminal are {N1, N2, N3, N4}, the base station may use 2 bits to indicate any one of the four candidates for the number of repeated transmissions. For example, {NDI, CSI request} can be set to {0, 0}=N1, {0, 1}=N2, {1, 0}=N3, {1, 1}=N4. Or, {CSI request, NDI} can be set to {0, 0}=N1, {0, 1}=N2, {1, 0}=N3, {1, 1}=N4.

[0206] The terminal can interpret the bit values ​​of two different fields among the fields of the DCI format 0_0 scrambled with TC-RNTI as field values ​​for repeated transmission of Msg3 PUSCH. Specifically, the terminal can interpret the X bit of one field of the DCI and the Y bit of another field other than the field including the X bit as field values ​​for repeated transmission of Msg3 PUSCH. For example, the X bit can indicate whether the terminal interprets the Y bit as a field value for repeated transmission of Msg3 PUSCH, and the Y bit can indicate the number of repeated transmissions of Msg3 PUSCH. For example, 1 bit of the NDI field can indicate whether the terminal interprets the Y bit of the FDRA field as a field value for repeated transmission of Msg3 PUSCH. At this time, if the value of 1 bit of the NDI field is '0', the Y bit of the FDRA field is not interpreted as a field value for repeated transmission of Msg3 PUSCH. If the value of 1 bit of the NDI field is '1', the Y bit of the FDRA field can be interpreted as a field value for repeated transmission of Msg3 PUSCH. At this time, the Y bit can indicate any one of the candidates for the number of repeated transmissions of Msg3 PUSCH preset to the terminal. For example, if the value of 1 bit of the NDI field is '1', the Y (e.g., 2) bit of the FDRA field can indicate any one of the four candidates for the number of repeated transmissions. Specifically, {00} of {FDRA} can be set to N1, {01}=N2, {10}=N3, and {11}=N4.As another example, 1 bit of the CSI request field can indicate whether the terminal interprets the Y bit of the HPN field as a field value for repeated transmission of Msg3 PUSCH, and if 1 bit of the CSI request field has a value of '0', the Y bit of the HPN field is not interpreted as a field value for repeated transmission of Msg3 PUSCH, and if 1 bit of the CSI request field has a value of '1', the Y bit of the HPN field can be interpreted as a Msg3 PUSCH repeated transmission field value. If 1 bit of the CSI request field has a value of '1', the Y (e.g., 2) bit of the HPN field can indicate any one of four numbers of repeated transmissions. Specifically, {00} of {HPN} can be set to N1, {01}=N2, {10}=N3, and {11}=N4.

[0207] iii) The UE may be instructed of the number of repeated transmissions of the Msg3 PUSCH through a specific field of the uplink grant of the random access response that schedules the initial transmission of the Msg3 PUSCH. The UE may repeatedly transmit the Msg3 PUSCH according to the instructed number of repeated transmissions. The UE may interpret the bit value of a specific field of the uplink grant as a field value for repeated transmission of the Msg3 PUSCH. In this case, a specific bit of the uplink grant may indicate any one of multiple numbers of repeated transmissions of the Msg3 PUSCH. The specific field of the uplink grant may be a CSI request, FDRA, TPC, or MCS field. In this case, since the CSI request field may not be used for transmission of the Msg3 PUSCH, the UE may interpret the value of the CSI request field as a field value for repeated transmission of the Msg3 PUSCH. For example, since a base station may schedule a UE with insufficient coverage with a small number of PRBs in the frequency domain, the UE may interpret the bit value of the FDRA field as a field value for repeated transmission of the Msg3 PUSCH. In addition, as another example, since a base station may schedule a UE with insufficient coverage to transmit a PUSCH with the highest possible transmit power, the UE may interpret some of the indices indicating low dB values ​​in the TPC field as field values ​​for repeated transmission of the Msg3 PUSCH. In this case, the TPC field may have a size of 3 bits, and the TPC value indicated by each codepoint is as shown in Table 6. In another example, a UE with insufficient coverage may be scheduled to transmit a PUSCH with the lowest possible modulation scheme (e.g., QPSK) and / or low coding rate. Therefore, the UE may interpret some of the lower indices among the first 16 MCS indices (0 to 15) of Tables 4 and 5 included in the MCS field as fields for repeated transmission of the Msg3 PUSCH.

[0208]

[0209] Below, we further explain how to interpret a specific number of bits in the uplink grant of the random access response. The candidate numbers of repeated transmissions of the Msg PUSCH configured for the UE can be {N1, N2, N3, N4}.

[0210] The bit value of any one of the fields of the uplink grant can be set to indicate the number of repeated transmissions of Msg3 PUSCH. That is, the terminal can interpret the value of X bits of a specific field among the CSI request, FDRA, TPC, and MCS fields as the Msg3 PUSCH repeated transmission field value.

[0211] For example, the base station can set the X (e.g., 2) bit of the FDRA field as a field for repeated transmission of Msg3 PUSCH, and the base station can indicate any one of four (N1, N2, N3, N4) numbers of repeated transmissions using the X (e.g., 2) bit. The terminal can determine N1 if the bit value of the FDRA field is '00', N2 if it is '01', N3 if the FDRA field is '10', and N4 if the FDRA field is '11'. The X bit of the FDRA field can be determined as X = ceil (log2 (M)) when there are M candidates for the number of repeated transmissions set in the upper layer. In this specification, ceil (x) is a function that returns the smallest integer among integers greater than or equal to x. The X bit can be X bits from the MSB (most significant bit) excluding the bit(s) indicating frequency hopping in the FDRA field. Specifically, if the number of RBs included in the initial UL BWP is less than 50, the X bits may be X bits starting from the second bit of the FDRA field, and if the number of RBs is greater than or equal to 50, the X bits may be X bits starting from the third bit of the FDRA field.

[0212] For example, the base station sets the X (e.g., 2) bit of the TPC field as the bit of the field for repeated transmission of Msg3 PUSCH, and the base station can indicate one of four numbers of repeated transmissions using the 2 bits of the TPC field. The terminal can determine N1 if the bit value of the TPC field is '00', N2 if it is '01', N3 if it is '10', and N4 if it is '11'. The X bit of the TPC field can be determined as X=ceil(log2(M)) when there are M candidates for the number of repeated transmissions set in the upper layer. The X bit can be the most leading (MSB) X bit or the most trailing (LSB) X bit of the 3-bit TPC field.

[0213] For example, the base station sets the X (e.g., 2) bits of the MCS field as bits of the field for repeated transmission of Msg3 PUSCH, and the base station can indicate one of four numbers of repeated transmissions using the 2 bits of the MCS field. The terminal can determine N1 if the bit value of the MCS field is '00', N2 if it is '01', N3 if it is '10', and N4 if it is '11'. In the MCS field, the X bit can be determined as X=ceil(log2(M)) when there are M candidates for the number of repeated transmissions set in the upper layer. The X bit can be the most leading (MSB) X bit or the most trailing (LSB) X bit in the 4-bit MCS field.

[0214] The terminal can interpret the number of repeated transmissions of Msg3 PUSCH by combining the bit values ​​of two different fields among the fields of the uplink grant of the random access response. If the number of bits required to set the number of repeated transmissions of Msg3 PUSCH is Z, the terminal can interpret Z bits, which are a combination of bits of two different fields, as the number of repeated transmissions of Msg3 PUSCH. The terminal can interpret the X bit of the first field and the Y bit of the second field among the CSI request, FDRA, TPC, and MCS fields as bits for repeated transmission of Msg3 PUSCH. The first field and the second field are different fields, and X+Y=Z. In addition, X <Z, Y<Z이고, Z는 적어도 2 비트 이상일 수 있다. 한편 제1 필드의 X=Z 비트를 단말이 Msg3 PUSCH의 반복 전송 횟수로 해석할 수 있는 경우, 제1 필드의 X 비트를 이용하여 Msg3 PUSCH의 반복 전송 횟수는 지시될 수 있다.

[0215] If there are M candidates for the number of repeated transmissions of Msg3 PUSCH (e.g., 4 {N1, N2, N3, N4}), Z bits are required to indicate the number of repeated transmissions to the UE. At this time, Z can be Z=ceil(log2(M)) bits. If M is 4, Z is 2. For example, the X (e.g., 1) bit of the first field (e.g., CSI request field) and the Y (e.g., 1) bit of the second field (e.g., FDRA field, MCS field) can be interpreted as bits for repeated transmission of Msg3 PUSCH, and the base station can indicate any one of the four numbers of repeated transmissions using 2 bits. If {the value of 1 bit of the first field, the value of 1 bit of the second field} is {0, 0}, the number of repeated transmissions can be set to N1, if {0, 1} it can be set to N2, if {1, 0} it can be set to N3, and if {1, 1} it can be set to N4.

[0216] In addition to the embodiments described above, the field for repeated transmission of Msg3 PUSCH in the DCI format 0_0 scrambled with TC-RNTI and the uplink grant of the random access response may be at least one field among the TDRA, FDRA, MCS, and TPC fields. In this case, the terminal may perform repeated transmission of Msg3 PUSCH by reinterpreting the bit values ​​of one or more fields. The following additionally describes a specific method for interpreting the bit values ​​of the fields. The candidates for the number of repeated transmissions of Msg PUSCH set to the terminal may be {N1, N2, N3, N4}.

[0217] The terminal can perform repeated transmission of Msg3 PUSCH based on the number of symbols scheduled (allocated) by the TDRA field. For example, if the number of symbols allocated to transmission of Msg3 PUSCH is 1 to (M1-1), the terminal can determine the number of repeated transmissions as N1, if the number of symbols allocated to transmission of Msg3 PUSCH is M1 to (M2-1), the number of repeated transmissions as N2, if the number of symbols allocated to transmission of M2 to (M3-1), the number of repeated transmissions as N3, and if the number of symbols allocated to transmission of M3 to (M4-1) are M4. In this case, M1 <M2<M3<M4 이고, N1> N2>N3>N4 may be the case. This is because coverage shortages can worsen when the base station allocates fewer symbols to the terminal. In other words, when fewer symbols are allocated, the terminal can transmit the Msg3 PUSCH more repeatedly. As another example, N1 <N2<N3<N4일 수 있다. 이는 기지국이 커버리지가 부족한 단말에게 많은 수의 심볼을 할당할 수 있기 때문이다. 즉, 기지국이 심볼 수를 많게 할당하는 경우, 단말은 Msg3 PUSCH를 보다 더 많이 반복 전송할 수 있다. 이때 할당되는 심볼 수는 상위 계층으로부터 설정될 수 있고, 구체적으로 SIB1 또는 다른 SIB들을 통해 설정될 수 있다.

[0218] The UE can perform repeated transmission of Msg3 PUSCH based on the number of PRBs scheduled by the FDRA field. For example, if the number of PRBs allocated to PUSCH transmission is 1 to (M1-1), the UE can determine the number of repeated transmissions as N1, if the number of PRBs allocated to PUSCH transmission is M1 to (M2-1), the number of repeated transmissions as N2, if the number of PRBs allocated to PUSCH transmission is M2 to (M3-1), the number of repeated transmissions as N3, and if the number of PRBs allocated to PUSCH transmission is M3 to (M4-1), the number of repeated transmissions as N4. M1 <M2<M3<M4이고, N1> N2 > N3 > N4. This is because coverage shortages can worsen when the base station allocates fewer PRBs to the UE. In other words, when fewer PRBs are allocated, the UE can transmit the Msg3 PUSCH more repeatedly. Another example is N1. <N2<N3<N4일 수 있다. 이는 기지국이 커버리지가 부족한 단말에게 많은 수의 PRB를 할당할 수 있기 때문이다. 즉, 기지국이 PRB 수를 많게 할당하는 경우, 단말은 Msg3 PUSCH를 보다 더 많이 반복 전송할 수 있다. 이때 할당되는 PRB의 수는 상위 계층으로부터 설정될 수 있고, 구체적으로 SIB1 또는 다른 SIB들을 통해 설정될 수 있다.

[0219] The terminal can perform repeated transmission of Msg3 PUSCH based on the modulation method or coding rate indicated by the MCS field. For example, if the index in the MCS table indicated by the MCS field is 0 to (M1-1), the terminal can determine the number of repeated transmissions as N1, if it is M1 to (M2-1), the number of repeated transmissions as N2, if it is M2 to (M3-1), the number of repeated transmissions as N3, and if it is M3 to (M4-1), the number of repeated transmissions as N4. M1 <M2<M3<M4이고, N1> It could be N2>N3>N4. This is because the base station can set a lower modulation scheme or coding rate for terminals with insufficient coverage. In other words, the lower the modulation scheme or coding rate, the more times the terminal can repeat the Msg3 PUSCH transmission.

[0220] The terminal can perform repeated transmission of Msg3 PUSCH based on the TPC command indicated by the TPC field. For example, the terminal can determine the number of repeated transmissions as N1 if the TPC command index indicated by the TPC field is 0 to (M1-1), as N2 if the number of repeated transmissions is M1 to (M2-1), as N3 if the number of repeated transmissions is M2 to (M3-1), and as N4 if the number of repeated transmissions is M3 to (M4-1). M1 <M2<M3<M4이고, N1> It can be N2>N3>N4. This is because the base station can set a high TPC command value to transmit at high power to a terminal with insufficient coverage. In other words, the higher the TPC command value, the more times the terminal can repeatedly transmit the Msg3 PUSCH.

[0221] The UE can perform repeated transmission of Msg3 PUSCH based on the TB size. For example, the UE can determine the TB size in which Msg3 PUSCH is transmitted based on the FDRA, TDRA, and / or MCS fields. If the determined TB size is 0 to (M1-1), the UE can determine the number of repeated transmissions as N1, if it is M1 to (M2-1), the number of repeated transmissions as N2, if it is M2 to (M3-1), the number of repeated transmissions as N3, and if it is M3 to (M4-1), the number of repeated transmissions as N4. M1 <M2<M3<M4이고, N1> This can be N2>N3>N4. This is because the base station can set a smaller TB size for terminals with insufficient coverage. In other words, the smaller the TB size, the more often the terminal can repeat the Msg3 PUSCH transmission.

[0222] iv) The terminal may receive a TDRA table including the number of repeated transmissions of the Msg3 PUSCH from the base station. Each entry of the TDRA table may include resource information in the time domain of the Msg3 PUSCH and information on the number of repeated transmissions. In addition, each entry may include the same number of repeated transmissions or different numbers of repeated transmissions. The terminal may determine the number of repeated transmissions of the Msg3 PUSCH by referring to the TDRA table. For example, if the terminal is configured to repeatedly transmit the Msg3 PUSCH, the terminal may perform repeated transmissions of the Msg3 PUSCH by referring to the TDRA table. On the other hand, if the terminal is configured not to repeatedly perform the Msg3 PUSCH, the terminal may transmit the Msg3 PUSCH by referring to the conventional TDRA table. In this case, the conventional TDRA table may mean a table that does not include the number of repeated transmissions of the Msg3 PUSCH.

[0223] One or more of the repetition transmission counts described herein may be values ​​commonly used for the initial transmission and retransmission of the Msg3 PUSCH or may be used independently. When the base station instructs the retransmission of the Msg3 PUSCH, the UE may determine the repetition transmission count for the retransmission of the Msg3 PUSCH based on the repetition transmission count instructed for the initial transmission of the Msg3 PUSCH.

[0224] The terminal can determine the number of repeated transmissions for retransmission of Msg3 PUSCH through bits of a specific field of DCI transmitted by the base station or can determine the number of repeated transmissions for retransmission of Msg3 PUSCH through the TDRA table. In this case, the DCI may be a DCI in DCI format 0_0 with a CRC scrambled with TC-RNTI.

[0225] a) The value of the bit may indicate that the number of repetitions for the retransmission of the Msg3 PUSCH is the same as the number of repetitions for the initial transmission of the Msg3 PUSCH. For example, if the values ​​of some or all bits of the bit are 0, the terminal may determine that the number of repetitions for the retransmission of the Msg3 PUSCH is the same as the number of repetitions for the initial transmission of the Msg3 PUSCH.

[0226] b) The number of repeated transmissions for retransmission of Msg3 PUSCH can be determined based on the number of repeated transmissions for the initial transmission of Msg3 PUSCH.

[0227] bi) One of the bit values ​​of the DCI may indicate that the number of repeated transmissions for the retransmission and initial transmission of the Msg3 PUSCH is the same.

[0228] b-ii) One of the bit values ​​of the DCI may indicate that the number of repetitions for the retransmission of the Msg3 PUSCH is greater than the number of repetitions for the initial transmission of the Msg3 PUSCH. Specifically, one of the bit values ​​of the DCI may indicate that the number of repetitions for the retransmission of the Msg3 PUSCH is twice as large as the number of repetitions for the initial transmission of the Msg3 PUSCH. If the number of repetitions for the initial transmission of the Msg3 PUSCH has already reached the maximum number of repetitions (or if the determined number of repetitions for the retransmission of the Msg3 PUSCH exceeds the maximum number of repetitions), the UE may perform Msg3 PUSCH retransmission according to the maximum number of repetitions.

[0229] b-iii) One of the bit values ​​of the DCI may indicate that the number of repetitions for the retransmission of the Msg3 PUSCH is smaller than the number of repetitions for the initial transmission of the Msg3 PUSCH. Specifically, one of the bit values ​​of the DCI may indicate that the number of repetitions for the retransmission of the Msg3 PUSCH is half the number of repetitions for the initial transmission of the Msg3 PUSCH. If the number of Msg3 PUSCH initial repetitions has already reached the minimum number of repetitions (e.g., the number of repetitions is 1) (or if the determined number of repetitions of the Msg3 PUSCH retransmission is smaller than the minimum number of repetitions (e.g., the number of repetitions is 1)), the UE may perform Msg3 PUSCH retransmission according to the minimum number of repetitions.

[0230] Bits of specific fields of the above-described DCI may be replaced by some entries of the TDRA table. For example, the number of repetitions for retransmission of Msg3 PUSCH indicated by some entries of the TDRA table may be equal to, greater than (e.g., twice as large) or less than (e.g., half as small) the number of repetitions for the initial transmission of Msg3 PUSCH.

[0231] How to stop repeated transmission of Msg3 PUSCH

[0232] If the terminal is configured by the base station to repeatedly transmit the Msg3 PUSCH K times, the terminal may repeatedly transmit the Msg3 PUSCH K times. In this case, since the repeatedly transmitted Msg3 PUSCHs are the same, if the base station successfully receives some of the K Msg3 PUSCHs, repeated transmission of the Msg3 PUSCH may not be necessary. Therefore, a method for stopping repeated transmission of the Msg3 PUSCH is described below.

[0233] i) The terminal can determine whether to repeatedly transmit Msg3 PUSCH based on whether or not the PDCCH scheduling Msg4 is received. The terminal can detect the PDCCH scheduling Msg4 transmitted from the base station after the first transmission of Msg3 PUSCH. At this time, if the terminal receives the PDCCH scheduling Msg4, the terminal can recognize that the base station has successfully received the Msg3 PUSCH. Therefore, if the terminal schedules the PDCCH scheduling Msg4, the terminal can stop the subsequent repeated transmission of Msg3 PUSCH. The PDCCH scheduling Msg4 can include DCI in DCI format 1_0 scrambled with TC-RNTI.

[0234] ii) The terminal can determine whether to repeatedly transmit the Msg3 PUSCH based on whether or not the PDCCH scheduling the retransmission of the Msg3 PUSCH is received. The terminal can detect the PDCCH scheduling the retransmission of the Msg3 PUSCH transmitted from the base station after the transmission of the first Msg3 PUSCH. At this time, if the terminal receives the PDCCH scheduling the Msg3, the terminal can receive scheduling information of a new Msg3 PUSCH. Accordingly, the terminal can stop the repeated transmission of the Msg3 PUSCH that is currently being transmitted. The PDCCH scheduling the Msg3 PUSCH can include DCI in DCI format 0_0 scrambled with TC-RNTI.

[0235] iii) The UE can determine whether to repeatedly transmit the Msg3 PUSCH based on whether the uplink grant of the random access response (Msg2) scheduling the initial transmission of the Msg3 PUSCH is received. The UE can receive the PDCCH scheduling the uplink grant of Msg2 and the uplink grant of Msg2 after the transmission of the first Msg3 PUSCH. If the UE receives the uplink grant of Msg2 or the PDCCH scheduling the uplink grant of Msg2, the UE can configure scheduling information for a new Msg3 PUSCH. Accordingly, the UE can stop the repeated transmission of the Msg3 PUSCH that is currently being transmitted. The PDCCH scheduling the uplink grant of Msg2 can include a DCI in DCI format 1_0 scrambled with RA-RNTI.

[0236] iv) The terminal may perform repeated transmission of Msg3 PUSCH within a specific time window, and may stop the repeated transmission of Msg3 PUSCH when the specific time window ends. At this time, the repeated transmission of Msg3 PUSCH may not be transmitted in a specific situation (e.g., a situation in which the repeated transmission of Msg3 PUSCH in i) to iii) described above is stopped) and may be deferred to a subsequent slot. Therefore, the repeated transmission of Msg3 PUSCH may be postponed after a certain period of time. To prevent this, the terminal may perform repeated transmission of Msg3 PUSCH only during a specific period of time (slot) from the first transmission of Msg3 PUSCH. That is, the terminal may perform repeated transmission of Msg3 PUSCH within a specific period of time (slot), but may no longer perform repeated transmission of Msg3 PUSCH when the specific period of time (slot) ends.

[0237] As described above, the terminal may reinterpret the CSI request field, FDRA field, TPC, and MCS fields to determine the number of repeated transmissions of the Msg3 PUSCH. Below, a method for determining whether the terminal should reinterpret the CSI request field, FDRA field, and TPC field to determine the number of repeated transmissions of the Msg3 PUSCH is described.

[0238] How to determine whether to reinterpret the field for the number of Msg3 PUSCH repeat transmissions

[0239] i) If the terminal receives separate PRACH resources (e.g., PRACH preamble, RACH occasion) for repeated transmission of Msg3 PUSCH from the base station and transmits PRACH to the base station on the separate PRACH resources, the terminal can reinterpret the CSI request field, the FDRA field, and the TPC field based on the above-described method. Conversely, a terminal that transmits a PRACH other than the separate PRACH resources can always reinterpret the CSI request field, the FDRA field, and the TPC field for the original purpose. At this time, the separate PRACH resource can be included in SIB1 and configured by the base station to the terminal. That is, the terminal can repeatedly transmit Msg3 PUSCH on a resource determined based on at least one of the PRACH preamble and the RACH occasion. For example, the base station can determine on which resource the PRACH transmitted by the terminal is transmitted. If the PRACH transmitted by the terminal is transmitted on the separate PRACH resource, the base station can indicate the number of repeated transmissions of the Msg3 PUSCH using at least one or two fields among the CSI request field, the FDRA field, and the TPC field. When indicating the number of repeated transmissions, the base station can also indicate the number of repeated transmissions as 1. That is, the Msg3 PUSCH can be set not to be repeatedly transmitted. In this case, the value of one of the multiple preset repeated transmission number candidates (e.g., N1, N2, N3, N4) can be set to '1'. In addition, N1 can be a value agreed upon in advance as 1 (not set separately), and the base station can set only the values ​​of N2, N3, and N4.

[0240] Meanwhile, the base station can indicate whether to perform repeated transmission of Msg3 PUSCH through a specific field (e.g., CSI request field). As described above, even if the terminal transmits PRACH on a resource separately configured by the base station, the base station can instruct not to perform repeated transmission of Msg3 PUSCH through a specific field. In this case, if the base station instructs to perform repeated transmission of Msg3 PUSCH through a specific field (e.g., CSI request field), the number of repeated transmissions can be indicated using at least one or two fields among the FDRA field and the TPC field. In this case, the base station does not need to indicate 1 as the number of repeated transmissions of Msg3 PUSCH. This is because the number of repeated transmissions of Msg3 PUSCH can be instructed not to be performed through the specific field. Therefore, the values ​​of the candidates for the number of repeated transmissions (N1, N2, N3, N4) may not include 1. That is, the candidates for the number of repeated transmissions may be set to a value greater than 1.

[0241] ii) The terminal may determine whether to reinterpret the CSI request field, the FDRA field, and the TPC field for the purpose of repeated transmission of the Msg3 PUSCH based on the value of a specific field. At this time, the specific field may be any one field of the uplink grant of the random access response. For example, the specific field may be the CSI request field, and at this time, whether to reinterpret may be determined based on the value of 1 bit of the CSI request field. If the value of the CSI request field is 0, the terminal may interpret the FDRA field and the TPC field for their original purpose (not for the purpose of repeated transmission of the Msg3 PUSCH). If the value of the CSI request field is 1, the terminal may reinterpret the FDRA field and the TPC field. At this time, since the CSI request field is used to determine whether to reinterpret, the CSI request field may be excluded from the fields reinterpreted for the repeated transmission of the Msg3 PUSCH described above.

[0242] Method for determining the transmission power command value

[0243] The terminal must determine the TPC command value for the Msg3 PUSCH. If the Msg3 PUSCH is repeatedly transmitted, the terminal may determine the TPC value as the highest 8 dB increase in the transmission power command value in Table 6. Meanwhile, if the terminal repeatedly transmits the Msg3 PUSCH, the base station may set a specific value as the TPC value for the terminal.

[0244] The terminal can determine the transmit power command value based on the remaining bit(s) excluding the X bits for repeated transmission of Msg3 PUSCH. Since the number of remaining bit(s) is 3-X, the remaining bit(s) can be 1 bit or 2 bits.

[0245] Below, a specific method for determining the TPC command value based on the remaining bit(s) is described.

[0246] i) If the remaining bit is 1 bit, the terminal can insert '11' into the 2 bits which are the MSB. Therefore, the terminal can determine the TPC value based on '11a' (where a is the remaining 1 bit value) and Table 6. If the remaining 1 bit value (a) is 0, it means '110', and since '110' is 6, it can mean a 6 dB increase if referencing Table 6. If the remaining 1 bit value (a) is 1, it means '111', and since '111' is 7, it can mean an 8 dB increase if referencing Table 6. That is, the terminal can be instructed to only the two highest TPC command values ​​(6, 7) if referencing Table 6.

[0247] ii) If the remaining bit is 1 bit, the TPC value can be determined according to the value of 1 bit. Specifically, the TPC value can be determined according to Table 7.

[0248]

[0249] Referring to Table 7, if the value of the remaining 1 bit (a) is '0', the terminal can use the TPC_0 value, and if the value of the remaining 1 bit is '1', the terminal can use the TPC_1 value. TPC_0 and TPC_1 may be preset values ​​or values ​​separately set by the base station. The TPC_0 and TPC_1 values ​​may be two values ​​among -6, -4, -2, 0, 2, 4, 6, and 8. The TPC_0 value may be one of the negative values ​​(or non-positive values) among -6, -4, -2, 0, 2, 4, 6, and 8, and the TPC_1 value may be one of the positive values. In addition, in order to expand the coverage of the PUSCH, the values ​​of TPC_0 to TPC_1 may be determined as two positive (or non-negative) values ​​among -6, -4, -2, 0, 2, 4, 6, and 8. The difference between the values ​​of TPC_0 and TPC_1 can be 4 dB. Specifically, TPC_0 can be 4 dB and TPC_1 can be 8 dB, or TPC_0 can be 2 dB and TPC_1 can be 6 dB, or TPC_0 can be 0 dB and TPC_1 can be 4 dB. Meanwhile, the difference between the values ​​of TPC_0 and TPC_1 can be 8 dB. Specifically, TPC_0 can be 0 dB and TPC_1 can be 8 dB.

[0250] If the remaining bits are 2 bits, similar to method i), the terminal can insert '1' into the MSB 1 bit. Therefore, the terminal can determine the TPC value based on '1ab' (where ab is the remaining 2 bit value) and Table 6. That is, if the remaining 2 bit value (ab) is 00, it means '100', and '100' is 4, so it can mean a 2dB increase. Similarly, if the remaining 2 bit value is 01, it means '101', and '101' is 5, so it can mean a 4dB increase. If the remaining 2 bit value is 10, it means '110', and '110' is 6, so it can mean a 6dB increase. If the remaining 2 bit value is 11, it means '111', and '111' is 7, so it can mean an 8dB increase. The terminal can only be instructed with the four highest TPC command values ​​(4, 5, 6, 7) in Table 6.

[0251] If the remaining bits are 2 bits, four TPC values ​​can be determined based on the remaining 2 bit values, similar to method ii). Specifically, the TPC values ​​can be determined according to Table 8.

[0252]

[0253] The terminal can use the TPC_0 value if the remaining 2 bit values ​​(ab) are '00', use the TPC_1 value if '01', use the TPC_2 value if '10', and use the TPC_3 value if '11'. TPC_0, TPC_1, TPC_2, and TPC_3 may be preset values ​​or values ​​separately set by the base station. The TPC_0, TPC_1, TPC_2, and TPC_3 values ​​may be four values ​​among -6, -4, -2, 0, 2, 4, 6, and 8. The TPC_0 value may be one of the negative values ​​(or non-positive values) among -6, -4, -2, 0, 2, 4, 6, and 8, and the TPC_1, TPC_2, and TPC_3 values ​​may be positive values. In addition, the values ​​of TPC_0 and TPC_1 can be negative values ​​(or non-positive values) among -6, -4, -2, 0, 2, 4, 6, and 8, and the values ​​of TPC_2 and TPC_3 can be positive values. In addition, in order to expand the coverage of PUSCH, the values ​​of TPC_0, TPC_1, TPC_2, and TPC_3 can be four positive values ​​(or non-negative values) among -6, -4, -2, 0, 2, 4, 6, and 8. In addition, the difference among the values ​​of TPC_0, TPC_1, TPC_2, and TPC_3 can be 4 dB. Specifically, TPC_0 can be -6 dB, TPC_1 can be -2 dB, TPC_2 can be 2 dB, and TPC_3 can be 6 dB. Additionally, TPC_0 can be -4dB, TPC_1 can be 0dB, TPC_2 can be 4dB, and TPC_3 can be 8dB.

[0254] The above describes the signaling method for the base station related to repeated transmission of the Msg3 PUSCH. Information related to repeated transmission of the Msg3 PUSCH could be configured using some bits in a specific field of the uplink grant or DCI of the random access response. However, using some bits can lead to overhead due to the need to add additional bits. Furthermore, information related to repeated transmission of the Msg3 PUSCH could be configured by reinterpreting specific fields of the uplink grant or DCI, or by reinterpreting bits in specific fields. This reinterpretation method can limit the flexible scheduling of the base station. Furthermore, the base station may not be aware of whether the UE supports repeated transmission of the Msg3 PUSCH. In this case, even if the base station configures information related to repeated transmission of the Msg3 PUSCH, the UE not only fails to perform repeated transmission of the Msg3 PUSCH, but may also misinterpret the uplink grant or DCI. To solve this, the following describes a method for notifying the base station of whether or not to perform repeated transmission of Msg3 PUSCH or the number of repeated transmissions when the terminal transmits Msg3 PUSCH to the base station.

[0255] Method of signaling information related to repeated transmissions via Msg3 PUSCH

[0256] FIG. 17 is a diagram illustrating repeated transmission of Msg3 PUSCH according to one embodiment of the present invention.

[0257] Referring to FIG. 17, a terminal can repeatedly transmit Msg3 PUSCH on four slots. Msg3 PUSCH transmitted in each slot can transmit the same TB. In each slot, the same TB can be repeatedly transmitted with the same or different RVs (redundancy versions). Msg3 PUSCH transmitted in each slot can include at least one DMRS symbol. A DMRS symbol can mean a symbol to which a DMRS is mapped. Msg3 PUSCH transmitted in each slot can include multiple DMRS symbols. Among the multiple DMRS symbols, the DMRS symbol transmitted earliest in time can be described as a first DMRS symbol, and the DMRS symbols transmitted thereafter can be described as additional DMRS symbols. In this specification, for convenience of explanation, the first DMRS symbol is described as a DMRS symbol, but it is obvious that it can also mean additional DMRS symbols.

[0258] Since the base station sets information related to transmission of Msg3 PUSCH to the terminal (e.g., via uplink grant), it knows in advance the resources (slot, symbol, PRB, etc.) in which the first Msg3 PUSCH (Msg3 PUSCH rep#1) is transmitted. In addition, the base station knows in advance the location of the DMRS symbol included in Msg3 PUSCH rep#1. The base station can receive Msg3 PUSCH rep#1 transmitted by the terminal based on the information related to repeated transmission. Since the same TB is repeatedly transmitted in each slot, the base station can decode the TB transmitted by Msg3 PUSCH rep#1 even if it receives only Msg3 PUSCH rep#1. However, in case of poor channel conditions, even if the base station receives Msg3 PUSCH rep#1, it may not be able to decode the TB transmitted by Msg3 PUSCH rep#1. At this time, the base station can receive the second Msg3 PUSCH (Msg3 PUSCH rep#2) in the next slot in which Msg3 PUSCH rep#1 is transmitted. Specifically, the base station can determine whether to receive Msg3 PUSCH rep#2 on the same symbol position and / or PRBs as Msg3 PUSCH rep#1 in the next slot in which Msg3 PUSCH rep#1 is transmitted. The base station cannot determine whether the terminal repeatedly transmits Msg3 PUSCH. Therefore, in order to determine whether to receive Msg3 PUSCH rep#2, the base station can measure the energy of the time-frequency resource in which Msg3 PUSCH rep#2 is expected to be transmitted, and measure the correlation of the DMRS in the time-frequency resource in which the DMRS of Msg3 PUSCH rep#2 is expected to be transmitted. Based on these measurement results, the base station can determine (confirm) whether the terminal transmitted Msg3 PUSCH rep#2.If the measurement result indicates that the base station has transmitted Msg3 PUSCH rep#2, the base station can combine Msg3 PUSCH#1 and Msg3 PUSCH#2 to obtain a lower code rate, which may increase the likelihood of decoding the TB transmitted by the Msg3 PUSCH. Since the code rate can be obtained, the likelihood of decoding the TB transmitted by the Msg3 PUSCH may increase. The process of the base station determining whether to repeatedly transmit the Msg3 PUSCH may be repeatedly performed in slots in which the Msg3 PUSCH is likely to be transmitted. However, in the case of a terminal that repeatedly transmits the Msg3 PUSCH, there may be a problem in that the performance of the above measurement result may be degraded because it may be located at the cell edge and have insufficient coverage. In addition, there may be a problem in that the complexity increases because the base station must check whether to repeatedly transmit the Msg3 PUSCH in every slot.

[0259] FIG. 18 is a diagram illustrating repeated transmission of Msg3 PUSCH using three DMRSs according to one embodiment of the present invention.

[0260] Referring to FIG. 18, there may be three ways for a UE to transmit Msg3 PUSCH. (a) The UE may transmit Msg3 PUSCH without repetition. In other words, the UE may transmit Msg3 PUSCH only in one slot and may not transmit Msg3 PUSCH repeatedly in subsequent slots. (b) The UE may transmit Msg3 PUSCH repeatedly twice. This can be applied when repeated transmission of Msg3 PUSCH is not necessary even under poor uplink channel conditions. (c) The UE may transmit Msg3 PUSCH repeatedly four times. This can be applied when the uplink channel conditions are worse compared to method (b).

[0261] Also, referring to FIG. 18, the UE may use DMRS to indicate to the base station the transmission method (whether to repeatedly transmit) of the Msg3 PUSCH. Specifically, when the UE transmits the Msg3 PUSCH by method (a), DMRS A may be used to indicate the transmission method of the Msg3 PUSCH. When the UE transmits the Msg3 PUSCH by method (b), DMRS B of Msg3 PUSCH rep#1 and Msg3 PUSCH rep#2 of each of two slots may be used to indicate the transmission method of the Msg3 PUSCH. When the UE transmits the Msg3 PUSCH by method (c), DMRS C of Msg3 PUSCH rep#1, Msg3 PUSCH rep#2, Msg3 PUSCH rep#3, and Msg3 PUSCH rep#4 of each of four slots may be used to indicate the transmission method of the Msg3 PUSCH. That is, when the base station receives DMRS A, Msg3 PUSCH can be recognized as being transmitted once, when receiving DMRS B, Msg3 PUSCH can be recognized as being repeatedly transmitted twice, and when receiving DMRS C, Msg3 PUSCH can be recognized as being repeatedly transmitted four times.

[0262] Different base sequences can be applied to DMRS A, DMRS B, and DMRS C. Since different base sequences are applied to DMRS A, DMRS B, and DMRS C, the base station can determine which base sequence is applied by measuring the correlation between each base sequence.

[0263] Although the basic sequences of DMRS A, DMRS B, and DMRS C are the same, they can be sequence initialized with different sequence initialization values. If DMRS A is sequence initialized with the first value, DMRS B and DMRS C can be sequence initialized with the second and third values, respectively. The base station can measure the correlation assuming that the sequences are initialized with the first, second, and third values, and can determine which sequence initialization value was used based on the correlation measurement result. For example, the DMRS of Mag3 PUSCH with transmit precoding enabled can be as shown in Equation 1.

[0264]

[0265] N in mathematical formula 1 slot symb is the number of symbols per slot, n μ s,f is the slot index within the frame with subcarrier spacing configuration μ, l is the OFDM symbol index within the slot, N ID nSCID is the DMRS sequence initialization value n SCID It can mean a scrambling identity according to (0 to 1). Referring to mathematical expression 1, DMRS A, DMRS B, and DMRS C can be distinguished by at least different c_init values.

[0266] DMRS A, DMRS B, and DMRS C can be transmitted through different DMRS ports. In other words, the UE can transmit Msg3 PUSCH through different DMRS ports. The base station can determine which DMRS is used based on the DMRS port of the Msg3 PUSCH transmitted by the UE.

[0267] The base station can determine whether the Msg3 PUSCH is repeatedly transmitted or how many times it is repeatedly transmitted by determining whether the DMRS in the first slot in which the Msg3 PUSCH is transmitted is DMRS A, DMRS B, or DMRS C. Then, the base station can receive the Msg3 PUSCH based on the DMRS determination result.

[0268] However, since a terminal with low coverage repeatedly transmits Msg3 PUSCH, the probability that the base station correctly determines the DMRS of Msg3 PUSCH may decrease. Therefore, the accuracy of the base station determining the transmission method of Msg3 PUSCH in the first slot through one of multiple DMRSs (DMRS A, DMRS B, DMRS C) may be low. Therefore, the following describes a method for a terminal to indicate the transmission method of Msg3 PUSCH using two DMRSs (DMRS A and DMRS B).

[0269] FIGS. 19 to 21 illustrate a Msg3 PUSCH transmission method using two DMRSs according to one embodiment of the present invention.

[0270] Referring to FIG. 19, (a) when Msg3 PUSCH is not repeatedly transmitted, DMRS A may be used to indicate a transmission method of Msg3 PUSCH. (b) when Msg3 PUSCH is repeatedly transmitted twice or (c) when Msg3 PUSCH is repeatedly transmitted four times, DMRS B may be used to indicate a transmission method of Msg3 PUSCH. That is, the UE may use DMRS A or DMRS B to inform the base station of whether Msg3 PUSCH is repeatedly transmitted. The base station may determine whether Msg3 PUSCH is repeatedly transmitted using the DMRS on the first slot in which Msg3 PUSCH is transmitted. For example, if the base station determines that the DMRS received is DMRS A, it may determine that Msg3 PUSCH is not repeatedly transmitted. Conversely, if the base station determines that the DMRS received is DMRS B, it may determine that Msg3 PUSCH is repeatedly transmitted.

[0271] DMRS A may be the same as or different from the DMRS of a UE that does not have the capability to repeatedly transmit Msg3 PUSCH. If the DMRSs are the same, even if the base station determines that the DMRS in the first slot is DMRS A, the base station cannot determine whether the UE that transmitted the Msg3 PUSCH is capable of repeated transmission of Msg3 PUSCH. Therefore, when instructing retransmission of Msg3 PUSCH, repeated transmission of the retransmission cannot be instructed, or even if instructed, it must additionally determine whether the retransmission was repeated. On the other hand, if the DMRSs are different (i.e., if the base station receives DMRS B), the base station can determine that the UE that transmitted the Msg3 PUSCH is capable of repeated transmission of Msg3 PUSCH. Therefore, when instructing retransmission of Msg3 PUSCH, the base station can instruct repeated transmission of the retransmission.

[0272] Referring to FIG. 20, if the UE does not transmit Msg3 PUSCH in slots subsequent to the first slot, it can transmit DMRS A on the first slot, and if Msg3 PUSCH is repeatedly transmitted in slots subsequent to the first slot, it can transmit DMRS B on the first slot. That is, if Msg3 PUSCH is not repeatedly transmitted or if Msg3 PUSCH transmitted on the first slot is the last among the repeatedly transmitted Msg3 PUSCHs, DMRS A can be used. For example, referring to FIG. 20(a), since the UE does not repeatedly transmit Msg3 PUSCH, DMRS A can be used. Referring to FIG. 20(b), since Msg3 PUSCH is repeatedly transmitted on the first slot and the second slot, DMRS B can be transmitted on the first slot and DMRS A can be transmitted on the second slot. Referring to FIG. 20 (c), since Msg3 PUSCH can be repeatedly transmitted on the first, second, third, and fourth slots, DMRS B can be transmitted on the first, second, and third slots, and DMRS A can be transmitted on the fourth slot. That is, the base station can determine whether the DMRS included in the Msg3 PUSCH is DMRS A or DMRS B for each slot, and if the DMRS determined in the first slot is DMRS A, it can determine that there is no Msg3 PUSCH transmitted on the slots after the first slot. Conversely, if the DMRS determined by the base station in the first slot is DMRS B, it can determine that Msg3 PUSCH is repeatedly transmitted on the slots after the first slot. Meanwhile, the base station can determine the DMRS for each slot, but it may not be necessary to determine the DMRS of a specific slot. For example, the candidates for the number of repeated transmissions of Msg3 PUSCH set to the terminal are {R_1, R_2, …}. , R_r}, DMRS A can be transmitted only on the R_1-th slot, the R_2-th slot, and the R_r-th slot. Therefore, the base station can transmit on R_1, R_2, ...By judging only the DMRS of the R_rth slot, it is possible to determine whether there is an additional transmission of Msg3 PUSCH. Specifically, if the candidate number of repeated transmissions of Msg3 PUSCH set to the terminal is {1, 2, 4}, DMRS A can be transmitted only on the first, second, and fourth slots. Therefore, if Msg3 PUSCH is repeatedly transmitted four times as shown in Fig. 20(c), the base station only needs to judge the DMRS of the first, second, and fourth slots. That is, there is no need to judge the DMRS of the third slot of Fig. 20(c). However, in the method described through Fig. 20, if the base station fails to receive the Msg3 PUSCH transmitting DMRS A, the base station cannot determine the slot in which the transmission of Msg3 PUSCH ends. For example, in the case of Msg3 PUSCH that is repeatedly transmitted twice, if the base station fails to receive Msg3 PUSCH including DMRS transmitted on the second slot, the base station cannot determine the slot in which transmission of Msg3 PUSCH ends.

[0273] Referring to FIG. 21, the terminal may transmit DMRS A in the Msg3 PUSCH of a specific number of consecutive slots. The specific number may be a predetermined value determined according to the number of repeated transmissions of the Msg3 PUSCH. The specific number may be a value corresponding to half of the number of repeated transmissions of the Msg3 PUSCH. That is, if the Msg3 PUSCH is repeatedly transmitted twice, the specific number may be 1, and if it is repeatedly transmitted four times, the specific number may be 2. In other words, if the Msg3 PUSCH is repeatedly transmitted R times, the specific number may be f(R / 2). In this case, f(x) may be a function that returns any one of a rounded down, rounded up, or rounded up value of x. The specific number of consecutive slots may be calculated from a slot in which the repeated transmission of the Msg3 PUSCH ends. Referring to FIG. 21(c), Msg3 PUSCH can be repeatedly transmitted four times, and Msg3 PUSCH including DMRS A can be transmitted on two consecutive slots (i.e., the third and fourth slots) from the last slot. In the case of the method through FIG. 21, if the base station determines that the DMRS transmitted on at least one of the third and fourth slots is DMRS A, the base station can know that the transmission of Msg3 PUSCH in the fourth slot is terminated.

[0274] In the two-DMRS method described in Figures 19 to 21, different DMRSs can be transmitted in different slots. However, if the base station must perform joint channel estimation, the same DMRS must be transmitted. Therefore, the two-DMRS method can be applied to all situations except when joint channel estimation is performed.

[0275] Information signaling method related to repeated transmission of Msg3 PUSCH through UCI bit

[0276] FIGS. 22 to 26 illustrate a method for determining the number of modulation symbols for multiplexing uplink control information included in Msg3 PUSCH according to one embodiment of the present invention.

[0277] The number of modulation symbols for transmitting uplink control information (UCI) per layer mapped to Msg3 PUSCH can be calculated as in Equation 2. Equation 2 can also be used to calculate the number of modulation symbols when transmitting HARQ-ACK by multiplexing it on PUSCH.

[0278]

[0279] O in Equation 2 UCI means the number of bits indicating whether repeated transmission of Msg3 PUSCH is performed and the number of times of repeated transmission. L UCI is O UCI It refers to the number of CRC bits used when channel coding β. PUSCH offset can be set via SIB as an offset value to determine the number of resources for mapping UCI to Msg3 PUSCH. C UL-SCH means the number of code blocks (CB) included in Msg3 PUSCH. K r means the size of the rth CB included in Msg3 PUSCH. M UCI sc (l) means the number of REs that can be used for UCI transmission in the lth symbol of Msg3 PUSCH. N PUSCH symb,all means the total number of symbols used for Msg3 PUSCH transmission including DMRS. can be set through SIB as a scaling value. l0 means the index of the first PUSCH symbol other than DMRS after the DMRS symbol. For example, if DMRS is transmitted in the lth symbol, M UCIsc (l) is 0, otherwise M UCI sc (l) is M PUSCH sc - M PT-RS sc (l) is. M PUSCH sc is the number of subcarriers scheduled for PUSCH in the frequency domain, M PT-RS sc (l) represents the number of subcarriers of the lth PUSCH symbol including PTRS. The terminal calculates Q' from Equation 2. UCI UCI can be multiplexed onto PUSCH based on the number of modulation symbols (number of REs). Q' UCI The modulation symbol of the dog is Q' of Msg3 PUSCH UCI can be mapped to REs. At this time, the mapping method can be the same as the mapping method when HARQ-ACK is multiplexed on PUSCH. That is, Q' in the symbol immediately following the DMRS symbol of Msg3 PUSCH UCI A number of REs can be selected.

[0280] A terminal that does not support repeated transmission of Msg3 PUSCH cannot transmit Msg3 PUSCH through UCI multiplexing. Therefore, when receiving Msg3 PUSCH, the base station needs to determine whether UCI is multiplexed. For example, if the size of the UCI bit is less than or equal to 2 bits, the terminal selects Q' among the REs where Msg3 PUSCH is transmitted. UCI Puncturing the REs of the dog and Q' UCI UCI can be transmitted from REs. Therefore, the base station may not need to distinguish whether UCI is multiplexed. That is, Q' where UCI is transmitted UCI Depending on the REs of the dog, the mapping of Msg3 PUSCH may not change. On the other hand, for example, if the size of the UCI bit is greater than 2 bits, Msg3 PUSCH may be mapped to Q' to which the UCI is mapped.UCI Msg3 PUSCH can be transmitted with rate matching around the REs. The base station must decode Msg3 PUSCH twice because the mapping of Msg3 PUSCH may change depending on the different rate matching, whether UCI is multiplexed or not. Therefore, to reduce the number of decoding operations at the base station, the size of the UCI bit needs to be limited to 2 bits or less.

[0281] When the size of the UCI bit is 1 bit, i) the UCI bit can indicate that the number of repeated transmissions of Msg3 PUSCH is 1 or R. R can be a value set in the SIB. 1 is not set separately, and if the value of the UCI bit is '0', the number of repeated transmissions can always be determined to be 1. ii) the UCI bit can indicate that the number of repeated transmissions of Msg3 PUSCH is R_1 or R_2. The values ​​of R_1 and R_2 can be values ​​set in the SIB. In this case, the values ​​of R_1 and R_2 may not be 1.

[0282] When the size of the UCI bit is 2 bits, the UCI bit can indicate i) that the number of repetition transmissions of Msg3 PUSCH is 1, R_1, R_2, or R_3. R_1, R_2, and R_3 can be values ​​set in the SIB. 1 is not set separately, and if the UCI bit is '00', the number of repetition transmissions can always be determined to be 1. ii) The UCI bit can indicate that the number of repetition transmissions of Msg3 PUSCH is R_1, R_2, R_3, or R_4. R_1, R_2, R_3, and R_4 can be values ​​set in the SIB.

[0283] If the terminal needs to indicate a wider range of repeat transmission counts, such as {1, 2, 4, 8, 16, 32}, the UCI bit size must be greater than 2 bits. A method for transmitting a UCI exceeding 2 bits is described below.

[0284] Referring to FIG. 23, a terminal can generate a sub-UCI by grouping UCI bits into groups of up to 2 bits. The terminal can transmit the sub-UCI in the first slot and the second slot, respectively. The terminal can multiplex and transmit the first sub-UCI in the Msg3 PUSCH in the first slot, and multiplex and transmit the second sub-UCI in the Msg3 PUSCH in the second slot. The base station can receive the first sub-UCI and the second sub-UCI transmitted in the first slot and the second slot, respectively, to generate the entire UCI bits. In addition, the base station can determine the number of repeated transmissions of the Msg3 PUSCH based on the entire UCI bits. Referring to FIG. 24, the terminal can transmit the Msg3 PUSCH by multiplexing a 1-bit UCI bit value of '0' or '1' into the Msg3 PUSCH in each slot. A UCI bit value of '0' may indicate that Msg3 PUSCH is repeatedly transmitted in the slot after the slot in which Msg3 PUSCH multiplexed with the UCI bit value of '0' is transmitted. A UCI bit value of '1' may indicate that the slot in which Msg3 PUSCH multiplexed with the UCI bit value of '1' is transmitted is the last slot in which Msg3 PUSCH is transmitted. Referring to Fig. 24(b), the UE may multiplex the UCI bit value of '0' into the Msg3 PUSCH transmitted on the first slot because Msg3 PUSCH is repeatedly transmitted in the second slot (the slot after the first slot). The UE may multiplex the UCI bit value of '1' into the Msg3 PUSCH transmitted on the second slot because the second slot is the last slot in which Msg3 PUSCH is repeatedly transmitted. Referring to FIG. 24(c), the terminal can multiplex the UCI bit value '0' into the Msg3 PUSCH transmitted on the first, second, and third slots, respectively.This is because Msg3 PUSCH is repeatedly transmitted on the second slot (the slot after the first slot), the third slot (the slot after the second slot), and the fourth slot (the slot after the third slot). The terminal can multiplex the UCI bit value '1' on the Msg3 PUSCH transmitted on the fourth slot. This is because the fourth slot is the last slot in which Msg3 PUSCH is repeatedly transmitted. The method of multiplexing the UCI bit value '0' or '1' described through Fig. 24 cannot determine the slot in which the repeatedly transmitted Msg3 PUSCH ends if the base station does not receive the Msg3 PUSCH multiplexed with the UCI bit value '1'. For example, in the case of Fig. 24(b), the number of repeated transmissions of Msg3 PUSCH is 2. At this time, if the base station does not receive the Msg3 PUSCH transmitted on the second slot, there is a problem in that the base station cannot determine the slot in which the repeated transmission of the Msg3 PUSCH ends because the base station cannot confirm the UCI bit value '1'.

[0285] The terminal can multiplex the UCI bit value '1' into the Msg3 PUSCH transmitted on a specific number of consecutive slots. The specific number may be a preset value determined based on the number of repeated transmissions of the Msg3 PUSCH. The specific number may be half the number of repeated transmissions of the Msg3 PUSCH. Specifically, if the Msg3 PUSCH is repeatedly transmitted twice, the specific number may be 1, and if the Msg3 PUSCH is repeatedly transmitted four times, the specific number may be 2. In other words, if the Msg3 PUSCH is repeated R times, the specific number may be f(R / 2). f(x) may be a function that returns any one of a rounded down value, a rounded up value, and a raised up value of x. The specific number of consecutive slots may be selected starting from the slot in which the Msg3 PUSCH is repeatedly transmitted for the last time. The selection may be made starting from the last slot in which this repeated transmission is performed. Referring to Fig. 25(c), Msg3 PUSCH can be repeatedly transmitted four times. The terminal can transmit Msg3 PUSCH by multiplexing UCI bit value '1' to each of Msg3 PUSCH transmitted on two consecutive slots (third and fourth slots) starting from the slot in which Msg3 PUSCH is last repeatedly transmitted. Comparing Fig. 24(c) and Fig. 25(c), in Fig. 25(c), if the base station confirms that the UCI bit value '1' is multiplexed to Msg3 PUSCH transmitted on at least one of the third and fourth slots, the base station can confirm that Msg3 PUSCH ends in the fourth slot.

[0286] According to the above method, since UCI is multiplexed in each slot, the number of REs to be used for Msg3 PUSCH transmission is reduced. Therefore, UCI needs to be multiplexed only in the fewest slots possible. For example, the base station can determine that an Msg3 PUSCH with an unmultiplexed UCI bit value of '1' is the same as one with a multiplexed UCI bit value of '1'. As another example, the UE can transmit the Msg3 PUSCH by multiplexing the UCI onto the Msg3 PUSCH at regular intervals. For example, the UE can bundle N slots in which the Msg3 PUSCH is repeatedly transmitted and multiplex the UCI into the first slot among the N bundled slots to transmit the Msg3 PUSCH. In this case, the N bundled slots can be described as a slot bundle. If Msg3 PUSCH is repeatedly transmitted in slot bundles after the first slot bundle, the UE can multiplex the UCI bit value '0' to the Msg3 PUSCH transmitted on the (first) slot included in the first slot bundle. If Msg3 PUSCH is not repeatedly transmitted in slot bundles after the first slot bundle, the UE can multiplex the UCI bit value '1' to the Msg3 PUSCH transmitted on the (first) slot included in the first slot bundle. That is, the first slot bundle may be the slot bundle in which Msg3 PUSCH is transmitted last. Referring to Fig. 26(b), the UE can configure a slot bundle by bundling two slots. The UE can multiplex the UCI bit value '1' to the Msg3 PUSCH transmitted on the first slot among the first slot bundles. This is because Msg3 PUSCH is not repeatedly transmitted in slot bundles after the first slot bundle. Referring to Fig. 26(c), a terminal can configure a slot bundle by bundling two slots. The terminal can multiplex the UCI bit value '0' into the Msg3 PUSCH transmitted on the first slot of the first slot bundle.This is because Msg3 PUSCH is repeatedly transmitted in the second slot bundle (the slot bundle after the first slot bundle). The terminal can multiplex the UCI bit value '1' into Msg3 PUSCH transmitted in the first slot of the second slot bundle. This is because Msg3 PUSCH is not repeatedly transmitted in the slot bundle after the second slot bundle.

[0287] How to determine the slot in which Msg3 PUSCH is repeatedly transmitted in a TDD situation

[0288] The base station can set the direction of the symbol for TDD operation.

[0289] A base station can set a cell common symbol direction for a terminal. The symbol direction can be set through SIB1 transmitted to a terminal existing in the cell. The base station can set a cell common symbol direction through tdd-UL-DL-ConfigurationCommon of SIB1. The cell common symbol direction can be determined as any one of an UL symbol, a DL symbol, and a flexible symbol. A cell common UL symbol refers to a symbol used only for uplink transmission. A cell common DL symbol refers to a symbol used only for downlink transmission. A cell common flexible symbol refers to a symbol whose specific direction is not determined and can be changed to a UL symbol or a DL symbol through separate configuration.

[0290] The base station can additionally configure a symbol direction specific to each UE. The symbol direction specific to each UE can be configured through RRC signaling during the random access process. Specifically, the UE can be configured with a UE-specific symbol direction specific to each UE through tdd-UL-DL-ConfigurationDedicated. Since the directions of the cell-common UL symbol and cell-common DL symbol have been determined, the directions can no longer be modified, and the cell-common flexible symbol can be configured with a UE-specific symbol direction. The UE-specific symbol direction can be determined as any one of a UE-specific UL symbol, a UE-specific DL symbol, and a UE-specific flexible symbol. A UE-specific UL symbol refers to a symbol used only for uplink transmission. A UE-specific DL symbol refers to a symbol used only for downlink transmission. A UE-specific flexible symbol refers to a symbol whose specific direction has not been determined and can be changed to a UL symbol or a DL symbol through separate configuration.

[0291] Before receiving RRC signaling, the UE can receive the cell common symbol direction through the received SIB1 and repeatedly transmit Msg3 PUSCH. Therefore, the UE must repeatedly transmit Msg3 PUSCH according to the cell common symbol direction. At this time, the UE cannot determine whether the cell common flexible symbol can be used for repeated transmission of Msg3 PUSCH. For example, the base station can set the cell common flexible symbol as a UE-specific DL symbol to another UE. In this case, if the UE repeatedly transmits Msg3 PUSCH using the cell common flexible symbol, it may cause interference to other UEs. Therefore, it must be determined whether the cell common flexible symbol can be used for repeated transmission of Msg3 PUSCH, and a method for determining this is described below.

[0292] Figures 27 and 28 illustrate resources that can be used for repeated transmission of Msg3 PUSCH according to one embodiment of the present invention. In Figures 27 and 28, a D slot refers to a slot including an overlapping symbol when at least one of the symbols scheduled to transmit Msg3 PUSCH overlaps with a cell-common DL symbol. A U slot refers to a slot including overlapping symbols when all symbols scheduled to transmit Msg3 PUSCH overlap with a cell-common UL symbol. An F slot refers to a slot including an overlapping symbol when at least one of the symbols scheduled to transmit Msg3 PUSCH overlaps with a cell-common flexible symbol (in this case, the symbols scheduled to transmit Msg3 PUSCH do not overlap with a cell-common DL symbol, but may overlap with a cell-common UL symbol).

[0293] Referring to FIG. 27, the terminal can be configured to repeatedly transmit Msg3 PUSCH on 6 consecutive slots. At this time, Msg3 PUSCH is transmitted in slots where Msg3 PUSCH transmission is possible, and Msg3 PUSCH may not be transmitted and may be dropped in slots where Msg3 PUSCH transmission is not possible. i) Referring to FIG. 27(a), the terminal can repeatedly transmit Msg3 PUSCH on slots remaining except for the D slot. That is, the terminal can repeatedly transmit Msg3 PUSCH on the F slot and the U slot, and may not transmit and drop the Msg3 PUSCH scheduled on the D slot. However, since Msg3 PUSCH may be transmitted using a cell common flexible symbol, there is a possibility of causing interference to other terminals. ii) Referring to FIG. 27(b), the terminal can repeatedly transmit Msg3 PUSCH only on the U slot. That is, the terminal can drop the Msg3 PUSCH scheduled on the D slot and the F slot without transmitting it. Since the terminal transmits the Msg3 PUSCH using only the UL symbol, it does not interfere with other terminals. iii) Referring to Fig. 27(c), the terminal performs the first transmission of the Msg3 PUSCH repeated transmission in the slot indicated by the uplink grant (i.e., the slot in which the first transmission among the repeated transmissions of the Msg3 PUSCH is performed), and can repeatedly transmit the Msg3 PUSCH only on the U slot in the subsequent slots. The terminal can drop the Msg3 PUSCH scheduled on the F slot and the D slot after the slot indicated by the uplink grant without transmitting it. The slot indicated by the uplink grant can be determined based on the slot in which the uplink grant is received and the K2 value. The K2 value is a value set by the base station and can mean an offset value from the slot in which the uplink grant is received. That is, if the slot in which the uplink grant is received is the nth slot, the slot indicated by the uplink grant may be the n+K2th slot.At this time, the slot indicated by the uplink grant may be an F slot or a U slot. The base station may intentionally configure the cell common flexible symbol to be used for Msg3 PUSCH transmission.

[0294] Referring to FIG. 28, the terminal can be configured to repeatedly transmit Msg3 PUSCH four times, i.e., to repeatedly transmit on four slots. Accordingly, the terminal must determine four slots in which repeated transmission of Msg3 PUSCH is possible. i) Referring to FIG. 28(a), the terminal can determine the remaining slots except for the D slot as slots in which transmission of Msg3 PUSCH is possible. That is, the terminal can repeatedly transmit Msg3 PUSCH on the F slot and the U slot. However, since Msg3 PUSCH may be transmitted using a cell common flexible symbol, there is a possibility of interference to other terminals. ii) Referring to FIG. 28(b), the terminal can repeatedly transmit Msg3 PUSCH only on the U slot. That is, the terminal cannot repeatedly transmit Msg3 PUSCH on the F slot and the U slot. Compared to the method described through Fig. 28(a) (i method), although Msg3 PUSCH is repeatedly transmitted in a later slot, since Msg3 PUSCH is repeatedly transmitted only on the U slot, there is an effect that it does not interfere with other terminals. iii) Referring to Fig. 28(c), the terminal performs the first transmission of Msg3 PUSCH repeated transmission in the slot indicated by the uplink grant (i.e., the slot in which the first transmission of Msg3 PUSCH repeated transmission is performed), and can repeatedly transmit Msg3 PUSCH only on the U slot in the subsequent slots. The terminal can drop Msg3 PUSCH scheduled in the F slot and D slot after the slot indicated by the uplink grant without transmitting it. The slot indicated by the uplink grant can be determined based on the slot in which the uplink grant is received and the K2 value. The K2 value is a value set by the base station and may mean an offset value from the slot in which the uplink grant is received. That is, if the slot in which the uplink grant is received is the nth slot, the slot indicated by the uplink grant may be the n+K2th slot. In this case, the slot indicated by the uplink grant may be the F slot or the U slot.The base station may intentionally configure the cell common flexible symbol to be used for Msg3 PUSCH transmission.

[0295] The base station can be configured to use any one of the methods described with reference to FIGS. 27 and 28 via an uplink grant. The base station can configure a method for determining a slot in which the Msg3 PUSCH is repeatedly transmitted using some bits of a specific field of the uplink grant, and the terminal can repeatedly transmit the Msg3 PUSCH based on the configured method. The Msg3 PUSCH in the method described with reference to FIGS. 27 and 28 may mean an Msg3 PUSCH initial transmission and an Msg3 PUSCH retransmission.

[0296] In the above description, the cell common DL symbol may additionally include symbols for which the Type-0 common search space (CSS) of CORESET0 is set. Here, CORESET0 represents the CORESET indicated by the PBCH (physical broadcast channel). Here, the Type-0 common search space is a search space that monitors the DCI format 1_0 that schedules the PDSCH that transmits SIB1. The DCI format has the CRC scrambled with SI-RNTI. That is, the terminal regards the symbol for which the reception of the Type-0 CSS of CORESET0 is set as a symbol that can only be received in downlink.

[0297] A cell common DL symbol may additionally include symbols to which the Type-0A CSS (Common Search Space) of CORESET0 is set. The Type-0A CSS may be a search space that monitors a DCI of DCI format 1_0 that schedules a PDSCH including a SIB excluding SIB1. At this time, the DCI may be CRC scrambled with SI-RNTI. A cell common DL symbol may additionally include symbols to which the Type-1 CSS of CORESET0 is set. The Type-1 CSS may be a search space that monitors a DCI that schedules a Msg2 PDSCH or a Msg 4 PDSCH. At this time, the DCI may be CRC scrambled with RA-RNTI, MsgB-RNTI, or TC-RNTI. A cell common DL symbol may additionally include symbols to which the Type-2 CSS of CORESET0 is set. The Type-2 CSS may be a search space that monitors a DCI that transmits paging information. At this time, the DCI may be CRC scrambled with P-RNTI. The cell common DL symbol may additionally include symbols with Type-3 CSS of CORESET0 set. Type-3 CSS may be a search space that monitors DCIs with various cell common DCI formats. At this time, the DCI may be CRC scrambled with INT-RNTI, SFI-RNTI, TPC-PUSCH-RNTI, TPC-PUCCH-RNTI, TPC-SRS-RNTI, CI-RNTI, C-RNTI, MCS-C-RNTI, CS-RNTI(s), or PS-RNTI.

[0298] The cell common DL symbol may additionally include symbols configured to receive SS / PBCH blocks. The symbols configured to receive SS / PBCH blocks may be configured via SIB1, specifically via ssb-PositionsInBurst in SIB1. In other words, the terminal may determine that the symbols configured to receive SS / PBCH blocks are symbols that can only receive downlink channels.

[0299] The cell common UL symbol may additionally include symbols configured to transmit a PRACH. The symbols configured to transmit a PRACH may be symbols corresponding to valid RACH occasions (ROs). The UE may receive a PRACH configuration from the base station via SIB1. Specifically, the PRACH configuration may be configured via rach-ConfigCommon of initialUplinkBWP of UplinkConfigCommonSIB of ServingCellConfigCommonSIB of SIB1. The UE may determine a valid RO via the PRACH configuration. The method for determining a valid RO is described below.

[0300] a. If tdd-UL-DL-ConfigurationCommon is not set to the terminal, then N is not ahead of the SS / PBCH block and starts from the last symbol of the SS / PBCH block. gap An RO that is more than a symbol away can be determined as a valid RO.

[0301] b. If tdd-UL-DL-ConfigurationCommon is set to the terminal, all symbols of the RO overlap with cell common UL symbols, or the RO does not precede the SS / PBCH block, and N symbols are from the last symbol of the SS / PBCH block. gap An RO that is more than a symbol away can be determined as a valid RO.

[0302] A terminal can transmit a PRACH using a valid RO. That is, the base station can consider a valid RO to be used for uplink channel transmission. The cell common UL symbol is N before a valid RO. gap may include symbols. At this time, the symbol scheduled for transmission of PRACH may be a symbol corresponding to a valid RO. The terminal may be N gap Because the downlink channel or signal is not received from the symbol. Therefore, the base station is gap The symbol can be considered as being used for uplink transmission. N gap It can be 0 if the subcarrier spacing of PRACH is 1.25 kHz or 5 kHz, and 2 if it is 15 kHz, 30 kHz, 60 kHz, or 120 kHz.

[0303] Frequency hopping method for repeated transmissions on uplink channels

[0304] Below, the frequency hopping method applied when a terminal repeatedly transmits an uplink channel is described.

[0305] The base station can configure long PUCCH (i.e., PUCCH formats 1, 3, and 4) to be repeatedly transmitted in 2, 4, or 8 slots to ensure coverage of the PUCCH of the terminal. When the terminal enters RRC_CONNECTED mode after initial cell access, the terminal can be configured with the number of PUCCH repetition transmissions (nrofSlots) for each PUCCH format through terminal-specific system information. For example, if the PUCCH formats transmitted on the resources configured for the terminal include all of PUCCH formats 1, 3, and 4, the number of repetition transmissions for each PUCCH format can be configured with a different number of PUCCH repetition transmissions (nrofSlots).

[0306] When a terminal is configured to repeatedly transmit a PUCCH N times, N slots in which PUCCH transmission is possible can be sequentially determined from a slot in which PUCCH transmission is configured or instructed. A slot in which PUCCH transmission is possible must not overlap with a symbol scheduled for PUCCH transmission within the slot and a symbol configured for reception of a semi-statically configured DL symbol or SS / PBCH block. If a symbol scheduled for PUCCH transmission overlaps with a symbol configured for reception of a semi-statically configured DL symbol or SS / PBCH block, the terminal does not transmit a PUCCH in the corresponding slot, and the corresponding slot may not be included in the N slots for PUCCH transmission.

[0307] The terminal can receive a new PUCCH repetition transmission setting from the base station before completing the PUCCH repetition transmission number set by the base station. When the terminal enters the RRC connected mode (RRC_CONNECTED mode) after the initial cell access, it is set to transmit the PUCCH repeatedly N times through the terminal-specific system information. However, if the channel environment improves thereafter, the terminal can transmit the PUCCH M( <N)번 반복 전송하도록 새롭게 설정 받아 상향링크 제어채널의 오버헤드 감소 및 상향링크 간섭을 줄일 수 있다. 반대로, 채널 환경이 나빠진 경우, 단말은 PUCCH를 M(> The coverage of the uplink control channel can be increased by newly configuring to be repeatedly transmitted N times. Here, the number of repeated transmissions (M) can include 1. That is, when the terminal receives a new configuration for repeated transmission of a PUCCH, it can ignore the previously configured configuration for repeated transmission of a PUCCH and repeatedly transmit a new PUCCH based on the new configuration for repeated transmission of the PUCCH.

[0308] A terminal can determine the number of repeated transmissions of a new PUCCH by receiving explicit information from a base station. The explicit information may be the number of PUCCH repetitions. The explicit information may be included in the DCI included in a PDCCH that schedules a PDSCH corresponding to the PUCCH. The PDSCH corresponding to the PUCCH may be a PUCCH that includes HARQ-ACK information of the corresponding PDSCH. The explicit information may be indicated with a size of ceil(log2(K)) bits when the number of configurable PUCCH repetitions is K. For example, when the configurable numbers of PUCCH repetitions are 1, 2, 4, and 8, since K=4, it may be indicated with ceil(log2(4))=2 bits. The number of PUCCH repetitions that can be indicated may be one of {1, 2, 4, 8}. The base station can explicitly set multiple PUCCH repetition counts among the instructable PUCCH repetition counts as information. For example, the base station can explicitly set {2, 4} among the PUCCH repetition counts {1, 2, 4, 8} as information. The instructable PUCCH repetition counts may be one of {1, 2, 4, 8, N}. N may be a value preset for each PUCCH format. The base station can explicitly set multiple PUCCH repetition counts among the instructable PUCCH repetition counts as information. In this case, the multiple PUCCH repetition counts set as explicit information may include N. For example, the base station can explicitly set {2, N} among the PUCCH repetition counts {1, 2, 4, 8, N}. The instructable PUCCH repetition counts may include at least one of {N / 4 N / 2, N, 2*N, 4*N}. At this time, the base station can set {N / 2, N} as the number of repeated transmissions of PUCCH.If N / 4 is explicitly set as information, the terminal can repeatedly transmit PUCCH as many as 1 / 4 of the preset N (i.e., 1 repetition when N=4, 2 repetitions when N=8). Similarly, if N / 2 is explicitly set as information, the terminal can repeatedly transmit PUCCH as many as 1 / 2 of the preset N (i.e., 1 repetition when N=2, 2 repetitions when N=4, 4 repetitions when N=8). If 2*N is explicitly set as information, the terminal can repeatedly transmit PUCCH as many as twice N (i.e., 2 repetitions when N=1, 4 repetitions when N=2, 8 repetitions when N=4). If 4*N is explicitly set as information, the terminal can repeatedly transmit PUCCH as many as 4 times N (i.e., 4 repetitions when N=1, 8 repetitions when N=2). If N / 4 and N / 2 are less than 1, the number of repeated transmissions of PUCCH can be 1. If 2*N and 4*N are greater than 8, the number of repeated transmissions of PUCCH can be 8.

[0309] Previously, the number of PUCCH repetitions could be set differently for each PUCCH format. Even if a resource for new PUCCH transmission is set for a terminal and the terminal transmits the new PUCCH, if the previous PUCCH format and the newly set PUCCH format are the same, the terminal can repeatedly transmit the newly set PUCCH as many times as the number of repetitions corresponding to the PUCCH format. For example, a PUCCH format transmitted on a resource with a PUCCH resource ID set to 0 may be PUCCH format 1 and the number of repetitions may be set to 8, and a PUCCH format transmitted on a resource with a PUCCH resource ID set to 1 may be PUCCH format 1 and the number of repetitions may be set to 2. Afterwards, if the PUCCH resource ID indicated in the PRI (PUCCH resource indicator, PRI) field of the DCI included in the PDCCH of the PDSCH corresponding to the PUCCH is 0, the terminal can repeatedly transmit the PUCCH of PUCCH format 1 in 8 slots, and if the PUCCH resource ID is 1, the terminal can repeatedly transmit the PUCCH of PUCCH format 1 in 2 slots. The number of PUCCH repetitions for each resource on which the PUCCH is transmitted can be one of the values ​​{1, 2, 4, 8}. Meanwhile, if the number of PUCCH repetitions is not set for the resource on which the PUCCH is transmitted, the terminal can repeatedly transmit the PUCCH according to the number of repetitions set according to the PUCCH format.

[0310] Below, a method for a base station to set frequency hopping when repeated transmission of PUCCH to a terminal is set is described.

[0311] Intra-slot frequency hopping

[0312] The terminal can divide the PUCCH in half in the time domain, map it to two hops within the slot configured for PUCCH transmission, and transmit the two hops to the base station. At this time, the PUCCH may or may not be transmitted repeatedly. If the length (number) of symbols allocated for PUCCH transmission in one slot is number of symbols, floor(number of symbols / 2) symbols can be mapped to the first hop, and number of symbols - floor(number of symbols / 2) symbols can be mapped to the second hop. The first hop can be transmitted on the first frequency band, and the second hop can be transmitted on the second frequency band. The PRB of the first hop can be composed of PRBs corresponding to the PRB corresponding to the number of PRBs configured by the base station, starting from the PRB corresponding to the starting PRB index configured by the base station. The PRB of the second hop may be composed of PRBs corresponding to the PRB index at which the second hop set from the base station starts, and PRBs corresponding to the number of PRBs set from the base station.

[0313] inter-slot frequency hopping

[0314] Based on the slot in which the first PUCCH of the repeatedly transmitted PUCCH is transmitted, the repeated transmission slot index (slot index for repetition) may be sequentially indexed based on the first slot of the PUCCH repeated transmission. The repetition transmission index of the slot in which the first PUCCH is transmitted may be 0. The repeated transmission slot index may be sequentially indexed for the slots after the slot in which the first PUCCH is transmitted. The repeated transmission slot index may be determined regardless of whether repeated transmission of the PUCCH is possible on the corresponding slot. For example, if the terminal is configured to repeatedly transmit the PUCCH 4 times in slot X, the terminal may determine the index of slot X as 0, the index of slot X+1 as 1, the index of slot X+2 as 2, and the index of slot X+3 as 3. The terminal may map the PUCCH to the first hop in the slot corresponding to the even-numbered repeated transmission slot index based on the determined repeated transmission slot index. The terminal may map the PUCCH to the second hop in the slot corresponding to the odd-numbered repetitive transmission slot index. The first hop may be transmitted on the first frequency band, and the second hop may be transmitted on the second frequency band. The PRB of the first hop may be composed of PRBs corresponding to the number of PRBs set by the base station, starting from the PRB corresponding to the starting PRB index set by the base station. The PRB of the second hop may be composed of PRBs corresponding to the number of PRBs set by the base station, starting from the PRB corresponding to the starting PRB index of the second hop set by the base station.

[0315] PUCCH frequency hopping method

[0316] The base station can configure the terminal to either frequency hop within a slot or frequency hop between slots.

[0317] The base station can configure whether or not to perform intra-slot frequency hopping for each resource configured for transmission of each PUCCH. For example, if a terminal is configured with a resource having a PUCCH resource ID of 1 within a resource set having a PUCCH resource set ID of 0, the terminal can be configured as to whether or not intra-slot frequency hopping is possible. If the base station configures intra-slot frequency hopping to be possible, the terminal can transmit the PUCCH through intra-slot frequency hopping, and if the base station configures intra-slot frequency hopping to not be possible, the terminal can transmit the PUCCH without performing intra-slot frequency hopping.

[0318] The base station can configure whether or not to perform frequency hopping between slots for each PUCCH format. For example, the base station can configure whether or not frequency hopping between slots is possible for PUCCH format 1. If the base station configures inter-slot frequency hopping as possible, the terminal can transmit the PUCCH through frequency hopping between slots regardless of the resources to which the PUCCH is configured. If the base station configures inter-slot frequency hopping as not possible, the terminal can transmit the PUCCH according to the resources to which the PUCCH is configured. In other words, the terminal can transmit the PUCCH depending on whether or not frequency hopping is possible within the slot configured for each resource to which the PUCCH transmission is configured.

[0319] When a terminal is configured to enable inter-slot frequency hopping for a specific PUCCH format, it can expect that resources transmitting PUCCHs of the specific PUCCH format will not be configured for intra-slot frequency hopping. That is, when a base station is configured to enable inter-slot frequency hopping according to a PUCCH format, it may not configure intra-slot frequency hopping according to resources transmitting PUCCHs.

[0320] A base station can set a repetition transmission count (N) greater than 1 and enable intra-slot hopping for the first PUCCH repeatedly transmitted in a specific PUCCH format. Thereafter, a terminal can set the repetition transmission count of a new PUCCH to 1. At this time, since intra-slot hopping is enabled, the terminal may not expect that the PUCCH is configured to enable inter-slot frequency hopping. That is, if a PUCCH in a specific PUCCH format is configured to perform inter-slot frequency hopping, the new PUCCH is not transmitted via intra-slot frequency hopping regardless of the number of repetitions of the new PUCCH. Therefore, a method for determining a frequency hopping method according to the number of repetitions of the new PUCCH is required.

[0321] FIG. 29 illustrates a method for determining a frequency hopping method according to the number of repeated transmissions of a PUCCH according to one embodiment of the present invention.

[0322] The terminal can determine the frequency hopping method by interpreting the upper layer field differently depending on the number of repeated transmissions of the new PUCCH. Specifically, the terminal can interpret the intra-slot frequency hopping or inter-slot frequency hopping value among the upper layer fields depending on whether the number of repeated PUCCH transmissions is 1. Referring to FIG. 29, nrofSlots indicates the number of repeated PUCCH transmissions configured from the base station, and intraSlotFrequencyHopping indicates whether intra-slot frequency hopping can be performed. If intraSlotFrequencyHopping is set to enabled, intra-slot frequency hopping can be performed, and if not set, intra-slot frequency hopping may not be performed. interslotFrequencyHopping indicates whether inter-slot frequency hopping is performed. If interslotFrequencyHopping is set to enabled, inter-slot frequency hopping can be performed, and if not set, inter-slot frequency hopping may not be performed. If the number of repetitions of a new PUCCH is 1, the terminal can check whether intra-slot frequency hopping is enabled regardless of whether inter-slot frequency hopping is set in the upper layer. If intra-slot frequency hopping is enabled, the terminal can transmit the new PUCCH by performing intra-slot frequency hopping. If the number of repetitions of a new PUCCH is not 1, the terminal can first check whether inter-slot frequency hopping is enabled in the upper layer. If inter-slot frequency hopping is enabled, the terminal can repeatedly transmit the new PUCCH by performing inter-slot frequency hopping. In this case, the PUCCH can be transmitted by performing only inter-slot frequency hopping regardless of whether intra-slot frequency hopping is set.If inter-slot frequency hopping is not enabled, the terminal can check whether intra-slot frequency hopping is enabled in the upper layer. If intra-slot frequency hopping is enabled, the terminal can repeatedly transmit a new PUCCH by performing intra-slot frequency hopping. If intra-slot frequency hopping is not enabled, the terminal can repeatedly transmit the PUCCH without performing frequency hopping.

[0323] In other words, the terminal can be configured to enable inter-slot frequency hopping for each PUCCH format. The terminal can be configured to enable intra-slot frequency hopping for each resource configured to transmit the PUCCH. In addition, the terminal can be configured to configure the number of PUCCH repetitions. Based on the number of repetitions, the terminal can determine whether to perform inter-slot frequency hopping based on whether the resource configured to transmit the PUCCH supports intra-slot frequency hopping. If the number of repetitions is 1, inter-slot frequency hopping may not be performed. If the number of repetitions is greater than 1 and inter-slot frequency hopping is configured to be enabled according to the PUCCH format, the terminal can perform inter-slot frequency hopping regardless of whether intra-slot frequency hopping is configured. Conversely, if the number of repetitions is greater than 1 and inter-slot frequency hopping is configured not to be enabled according to the PUCCH format, the terminal can perform frequency hopping depending on whether intra-slot frequency hopping is configured.

[0324] PUSCH frequency hopping method

[0325] Below, we describe the frequency hopping method for PUSCH. The frequency hopping method for PUSCH can be configured from a higher layer.

[0326] For example, the UE can determine a frequency hopping method by interpreting the bits of the frequency hopping flag in the DCI corresponding to the new PUSCH differently depending on the number of repeated transmissions of the new PUSCH. At this time, the DCI may be the DCI of the PDCCH that schedules the PUSCH. Specifically, the UE can interpret the 1-bit frequency hopping flag differently depending on whether the number of repeated transmissions of the new PUSCH is 1 or not. i) If the number of repeated transmissions of the new PUSCH configured for the UE is 1 and the bit value of the frequency hopping flag is 0, the UE can transmit the PUSCH without performing frequency hopping. ii) If the number of repeated transmissions of the new PUSCH configured for the UE is 1 and the bit value of the frequency hopping flag is 1, the UE can transmit the PUSCH by performing frequency hopping within the slot. iii) If the number of repeated transmissions of a new PUSCH configured for the terminal is greater than 1 and the bit value of the frequency hopping flag is 0, the terminal can transmit the PUSCH by performing frequency hopping within a slot. iv) If the number of repeated transmissions of a new PUSCH configured for the terminal is greater than 1 and the bit value of the frequency hopping flag is 1, the terminal can perform frequency hopping between slots to repeatedly transmit the PUSCH. As another example, i) if the number of repeated transmissions of a new PUSCH configured for the terminal is 1 and the bit value of the frequency hopping flag is 0, the terminal can transmit the PUSCH without performing frequency hopping. ii) If the number of repeated transmissions of a new PUSCH configured for the terminal is 1 and the bit value of the frequency hopping flag is 1, the terminal can perform frequency hopping within a slot to transmit the PUSCH. iii) If the number of repeated transmissions of a new PUSCH set by the terminal is greater than 1 and the bit value of the frequency hopping flag is 0, the terminal can repeatedly transmit the PUSCH without performing frequency hopping.iv) If the number of repeated transmissions of a new PUSCH set by the terminal is greater than 1 and the bit value of the frequency hopping flag is 1, the terminal can repeatedly transmit the PUSCH by performing frequency hopping between slots.

[0327] The terminal may be configured with a pair of the number of repetitive transmissions and the frequency hopping method of a new PUSCH, and may determine the number of repetitive transmissions and the frequency hopping method of the new PUSCH by interpreting the bits of the frequency hopping flag of the DCI corresponding to the new PUSCH differently. The DCI corresponding to the new PUSCH may be the DCI of the PDCCH that schedules the PUSCH. Specifically, the terminal may be configured with a pair (i.e., the number of repetitive transmissions, the hopping method) of the new PUSCH from the base station through the DCI corresponding to the new PUSCH, and may transmit the new PUSCH. At this time, (the number of repetitive transmissions, the hopping method) may be configured up to two times. At this time, the hopping method may be one of three cases: frequency hopping within a slot, frequency hopping between slots, and not performing frequency hopping.

[0328] Frequency hopping method of Msg3 PUSCH

[0329] The new PUSCH described above may be a new Msg3 PUSCH scheduled by the uplink grant of the random access response. The number of repeated transmissions of the new Msg3 PUSCH may be included in the uplink grant. The following describes the frequency hopping method when the new Msg3 PUSCH is repeatedly transmitted.

[0330] The base station can set a frequency hopping method when repeatedly transmitting a new Msg3 PUSCH to obtain frequency diversification benefits. The frequency hopping method can be set by a 1-bit value of the frequency hopping flag of the uplink grant of the random access response that schedules the new Msg3 PUSCH. In the case of a retransmission Msg3 PUSCH, the frequency hopping method can be set by a 1-bit value of the frequency hopping flag of the DCI format 0_0 scrambled with a TC-RNTI that schedules the retransmission Msg3 PUSCH. If the bit value of the frequency hopping flag is 0, the terminal can repeatedly transmit the new Msg3 PUSCH without performing frequency hopping, and if the bit value of the frequency hopping flag is 1, the terminal can repeatedly transmit the new Msg3 PUSCH by performing frequency hopping within a slot. When a UE repeatedly transmits Msg3 PUSCH, inter-slot frequency hopping may be more advantageous than intra-slot frequency hopping in terms of DMRS overhead. Below, we describe how a UE performs inter-slot frequency hopping to repeatedly transmit a new Msg3 PUSCH.

[0331] The UE can determine the frequency hopping method by interpreting the bits of the frequency hopping flag according to the number of repeated transmissions of the new Msg3 PUSCH. Specifically, the UE can interpret the frequency hopping flag differently from before depending on whether the number of repeated transmissions of the new Msg3 PUSCH is 1 or not. For example, i) if the number of repeated transmissions of the new Msg3 PUSCH configured by the UE is 1 and the bit value of the frequency hopping flag is 0, the UE can repeatedly transmit the new Msg3 PUSCH without performing frequency hopping. ii) if the number of repeated transmissions of the new Msg3 PUSCH configured by the UE is 1 and the bit value of the frequency hopping flag is 1, the UE can transmit the new Msg3 PUSCH by performing frequency hopping within the slot. iii) If the number of new Msg3 PUSCH repetition transmissions set by the terminal is greater than 1 and the bit value of the frequency hopping flag is 0, the terminal may perform intra-slot frequency hopping to repeatedly transmit the new Msg3 PUSCH. iv) If the number of new Msg3 PUSCH repetition transmissions set by the terminal is greater than 1 and the bit value of the frequency hopping flag is 1, the terminal may perform inter-slot frequency hopping to repeatedly transmit the new Msg3 PUSCH. As another example, i) if the number of new Msg3 PUSCH repetition transmissions set by the terminal is 1 and the bit value of the frequency hopping flag is 0, the terminal may transmit the new Msg3 PUSCH without performing frequency hopping. ii) if the number of new Msg3 PUSCH repetition transmissions set by the terminal is 1 and the bit value of the hopping flag is 1, the terminal may perform intra-slot frequency hopping to transmit the new Msg3 PUSCH.iii) If the number of new Msg3 PUSCH repetition transmissions set by the terminal is greater than 1 and the bit value of the frequency hopping flag is 0, the terminal may decide to repeatedly transmit the new Msg3 PUSCH without performing frequency hopping. iv) If the number of new Msg3 PUSCH repetition transmissions set by the terminal is greater than 1 and the bit value of the frequency hopping flag is 1, the terminal may perform frequency hopping between slots to repeatedly transmit the new Msg3 PUSCH.

[0332] The terminal can receive the number of repetition transmissions and the frequency hopping method of the new Msg3 PUSCH as a pair, and can determine the number of repetition transmissions and the frequency hopping method of the new Msg3 PUSCH by interpreting the bits of the frequency hopping flag differently. Specifically, the terminal can receive the number of repetition transmissions and the frequency hopping method of the new PUSCH in the form of a pair (i.e., number of repetition transmissions, hopping method) from the base station through DCI corresponding to the new PUSCH, and transmit the new Msg3 PUSCH. Specifically, the pair indicating the number of repetition transmissions and the frequency hopping method of the new PUSCH can be determined by the uplink grant of the random access response that schedules the Msg3 PUSCH or the frequency hopping flag of the DCI with the DCI format 0_0. At this time, (the number of repetition transmissions, the hopping method) can be set to a maximum of two. At this time, the hopping method can be one of three cases: frequency hopping within a slot, frequency hopping between slots, and not performing frequency hopping.

[0333] Figure 30 is a flowchart illustrating a method for a terminal to transmit Msg3 PUSCH according to one embodiment of the present invention.

[0334] The following describes a method for transmitting Msg3 PUSCH by a terminal described through FIGS. 1 to 29 through FIG. 30.

[0335] A terminal may receive a system information block 1 (SIB1) from a base station (S3010). At this time, the system information block 1 may be another system information block as described above (e.g., SIBx, x=1, 2, 3…). The terminal may transmit a preamble for a random access procedure to the base station (S3020). The terminal may receive a random access response (RAR) to the preamble from the base station (S3030). The random access response may include information for scheduling a physical uplink shared channel (PUSCH) transmitted by the terminal to the base station. The terminal may transmit the PUSCH to the base station based on the random access response (S3040). The SIB1 may include information on a candidate set of the number of repetition transmissions including values ​​for one or more numbers of repetition transmissions for performing repeated transmissions of the PUSCH. The random access response may include information indicating any one of the values ​​for the one or more repetition transmission counts included in the repetition transmission count candidate set. The PUSCH may be transmitted repeatedly for any one of the values. The random access response may be a Physical Downlink Shared Channel (PDSCH) including an Uplink (UL) grant. In this case, the information indicating the any one value may be included in at least one of a Time Domain Resource Assignment (TDRA) field, a Modulation Coding Scheme (MCS) field, and a Transmission Power Control (TPC) field of the random access response.When information indicating one of the values ​​is included in the MCS field, the one of the values ​​may be indicated by one or more MSBs (Most Significant Bits) of the bits of the MCS field. Meanwhile, when information indicating one of the values ​​is included in the TPC field, the one of the values ​​may be indicated by one or more LSBs (Least Significant Bits) of the bits of the TPC field. Each of the values ​​for the one or more number of repeated transmissions may be a power of 2. Specifically, each of the values ​​for the one or more number of repeated transmissions may be 1, 2, 4, and 8. The SIB1 may include at least one of information related to the preamble and a RACH opportunity. In addition, the PUSCH may be transmitted on a resource determined based on at least one of information related to the preamble and a RACH opportunity.

[0336] After step S3040, the terminal may receive downlink control information (DCI) including information for scheduling a retransmission PUSCH from the base station. The terminal may repeatedly transmit the retransmission PUSCH to the base station based on the DCI. At this time, the information for scheduling the retransmission PUSCH may include information on the number of repetitions of the retransmission PUSCH. Information on the number of repetitions of the retransmission PUSCH may be included in a HARQ process number field of the DCI. The retransmission PUSCH may be the same as the PUSCH transmitted by the terminal in step S3040. The DCI may be transmitted by the base station when the base station fails to receive the PUSCH transmitted by the terminal. That is, when the base station fails to successfully receive the PUSCH transmitted by the terminal in step S3040, the base station may transmit information for scheduling the retransmission PUSCH to the terminal.

[0337] The random access response may include a frequency hopping flag indicating whether the PUSCH frequency hops. The PUSCH may be frequency hopped intra-slot or inter-slot based on any one of the values ​​and the frequency hopping flag. If any one of the values ​​is 1, and the value of the frequency hopping flag indicates that the PUSCH frequency hops, the PUSCH may be frequency hopped intra-slot. If the value of the frequency hopping flag indicates that the PUSCH does not frequency hop, the PUSCH may not frequency hop. On the other hand, if any one of the values ​​is greater than 1, and the value of the frequency hopping flag indicates that the PUSCH frequency hops, the PUSCH may be frequency hopped inter-slot. If the value of the frequency hopping flag indicates that the PUSCH does not frequency hop, the PUSCH may not frequency hop. At this time, the PUSCH may be the retransmission PUSCH.

[0338] The random access response may further include information about a resource on which the first repeated transmission of the PUSCH is performed. The information about the resource on which the first repeated transmission of the PUSCH is performed may be a slot offset value between the resource on which the random access response is received and the resource on which the first repeated transmission of the PUSCH is performed. The SIB1 may further include information related to a TDD (Time Division Duplex) configuration, and the information related to the TDD configuration may be information about the types of symbols constituting a slot. In this case, the types of the symbols may be any one of a downlink symbol configured to be available for downlink transmission, an uplink symbol configured to be available for uplink transmission, and a flexible symbol that is not configured as the downlink symbol or the uplink symbol. The PUSCH may be repeatedly transmitted in units of slots. The resource on which the first repeated transmission of the PUSCH is performed may be a resource located apart from the resource on which the random access response is received by the slot offset value. The resource on which the first repeated transmission of the PUSCH is performed is a flexible slot, and repeated transmissions after the first repeated transmission of the PUSCH may be performed on an uplink slot. The flexible slot may be configured to include at least one flexible symbol, and the uplink slot may be configured entirely with the uplink symbols. In this case, the PUSCH may be the retransmission PUSCH.

[0339] The terminal performing the method described in FIG. 30 may be the terminal described in FIG. 11. Specifically, the terminal may be configured to include a communication module for transmitting and receiving wireless signals and a processor for controlling the communication module. In this case, the processor of the terminal may perform the method for transmitting the Msg3 PUSCH described herein.

[0340] In addition, a base station receiving an Msg3 PUSCH transmitted by a terminal described in this specification may be configured to include a communication module for transmitting and receiving a wireless signal and a processor for controlling the communication module. In this case, the base station may be the base station described in FIG. 11. In this case, the processor of the base station may perform a method for receiving an Msg3 PUSCH transmitted by a terminal described in this specification.

[0341] Although the methods and systems of the present invention have been described with respect to specific embodiments, some or all of their components or operations may be implemented using a computing system having a general-purpose hardware architecture.

[0342] The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will readily appreciate that the present invention can be readily modified into other specific forms without altering the technical spirit or essential characteristics of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single entity may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined manner.

[0343] The scope of the present invention is indicated by the claims described below rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention.

Claims

1. In a wireless communication system, a method for transmitting an uplink channel, the method performed by a terminal is as follows: A step of receiving a System Information Block 1 (SIB1) from a base station; A step of transmitting a preamble for a random access procedure to the above base station; A step of receiving a random access response (RAR) for the preamble from the base station; The random access response includes information for scheduling a physical uplink shared channel (PUSCH) transmitted by the terminal to the base station; A step of transmitting the PUSCH based on the random access response to the base station is included, The above SIB1 includes information about a candidate set of the number of repetition transmissions including values ​​for one or more numbers of repetition transmissions for performing repeated transmissions of the PUSCH, The random access response includes information indicating one of the values ​​for the number of repetition transmissions included in the candidate set of the number of repetition transmissions, A method characterized in that the above PUSCH is transmitted repeatedly as many times as any one of the above values.

2. In paragraph 1, A method characterized in that the random access response is a Physical Downlink Shared Channel (PDSCH) including an uplink (UL) grant.

3. In paragraph 1, A method characterized in that the information indicating any one of the above values ​​is included in at least one of a Time Domain Resource Assignment (TDRA) field, a Modulation Coding Scheme (MCS) field, and a Transmission Power Control (TPC) field of the random access response.

4. In paragraph 3, If information indicating any of the above values ​​is included in the MCS field, A method characterized in that any one of the above values ​​is indicated by one or more MSBs (Most Significant Bits) of the bits of the MCS field.

5. In paragraph 3, If information indicating any of the above values ​​is included in the TPC field, A method characterized in that the above one value is indicated by one or more LSBs (Least Significant Bits) of the bits of the TPC field.

6. In paragraph 1, The above SIB1 includes at least one of information related to the preamble and a RACH opportunity, A method characterized in that the PUSCH is transmitted on a resource determined based on at least one of information related to the preamble and the RACH opportunity.

7. In paragraph 1, A step of receiving downlink control information (DCI) including information for scheduling a retransmission PUSCH from the base station; Further comprising a step of repeatedly transmitting the retransmission PUSCH based on the DCI to the base station, The information for scheduling the above retransmission PUSCH includes information on the number of repetitions of the above retransmission PUSCH, Information about the number of repetitions of the above retransmitted PUSCH is included in the HARQ process number field of the above DCI, The above retransmitted PUSCH is identical to the above PUSCH, A method characterized in that the DCI is transmitted by the base station when the base station fails to receive the PUSCH transmitted by the terminal.

8. In paragraph 7, The above DCI is scrambled with TC-RNTI, A method characterized in that the format of the above DCI is DCI format 0_0.

9. In paragraph 1, A method characterized in that each of the values ​​for the number of repetition transmissions above is a power of 2.

10. In paragraph 1, A method, characterized in that each of the values ​​for the number of repetition transmissions is 1, 2, 4 and 8.

11. In paragraph 1, The random access response includes a frequency hopping flag indicating whether the PUSCH is frequency hopping, A method characterized in that the PUSCH performs intra-slot frequency hopping or inter-slot frequency hopping based on one of the values ​​and the frequency hopping flag.

12. In paragraph 11, If any of the above values ​​is 1, If the value of the frequency hopping flag indicates that the PUSCH frequency hops, the PUSCH frequency hops within a slot (intra-slot), A method characterized in that the PUSCH does not frequency hop if the value of the frequency hopping flag indicates that the PUSCH does not frequency hop.

13. In paragraph 11, If any of the above values ​​is greater than 1, If the value of the frequency hopping flag indicates that the PUSCH frequency hops, the PUSCH frequency hops inter-slot, A method characterized in that the PUSCH does not frequency hop if the value of the frequency hopping flag indicates that the PUSCH does not frequency hop.

14. In paragraph 1, The above random access response further includes information about the resource on which the first repetition transmission of the PUSCH is performed, Information about the resource on which the first repetition transmission of the PUSCH is performed is a slot offset value between the resource that received the random access response and the resource on which the first repetition transmission of the PUSCH is performed. The above SIB1 further includes information related to TDD (Time Division Duplex) configuration, Information related to the above TDD configuration is information about the types of symbols that make up the slot. The types of the above symbols are any one of a downlink symbol set to be available for downlink transmission, an uplink symbol set to be available for uplink transmission, and a flexible symbol that is not set as the downlink symbol or the uplink symbol. The above PUSCH is repeatedly transmitted in slot units, A method characterized in that the resource on which the first repeated transmission of the PUSCH is performed is a resource located at a distance from the resource that received the random access response by the slot offset value.

15. In paragraph 14, The resource in which the first repetition transmission of the above PUSCH is performed is a flexible slot, After the first repeated transmission of the above PUSCH, repeated transmissions are performed on the uplink slot, The above flexible slot is configured to include at least one of the above flexible symbols, A method characterized in that all of the above uplink slots are composed of the above uplink symbols.

16. In a wireless communication system, in a terminal transmitting an uplink channel, the terminal, Transmitter and receiver; comprising a processor controlling the transceiver; The above processor, Receive System Information Block 1 (SIB1) from the base station, Transmitting a preamble for a random access procedure to the above base station, Receive a Random Access Response (RAR) for the preamble from the base station, The above random access response includes information for scheduling a physical uplink shared channel (PUSCH) transmitted by the terminal to the base station, Transmitting the PUSCH based on the random access response to the base station, The above SIB1 includes information about a candidate set of the number of repetition transmissions including values ​​for one or more numbers of repetition transmissions for performing repeated transmissions of the PUSCH, The random access response includes information indicating one of the values ​​for the number of repetition transmissions included in the candidate set of the number of repetition transmissions, A terminal characterized in that the above PUSCH is transmitted repeatedly as many times as any one of the above values.

17. In paragraph 16, A terminal characterized in that the information indicating any one of the above values ​​is included in at least one of a Time Domain Resource Assignment (TDRA) field, a Modulation Coding Scheme (MCS) field, and a Transmission Power Control (TPC) field of the random access response.

18. In paragraph 17, If information indicating any of the above values ​​is included in the MCS field, A terminal, characterized in that any one of the above values ​​is indicated by one or more MSBs (Most Significant Bits) of the bits of the MCS field.

19. In paragraph 17, If information indicating any of the above values ​​is included in the TPC field, A terminal, characterized in that any one of the above values ​​is indicated by one or more LSBs (Least Significant Bits) of the bits of the TPC field.

20. In a method for receiving an uplink channel in a wireless communication system, the method performed by a base station comprises: A step of transmitting System Information Block 1 (SIB1) to a terminal; A step of receiving a preamble for a random access procedure from the terminal; A step of transmitting a random access response (RAR) to the preamble to the terminal; The random access response includes information for scheduling a physical uplink shared channel (PUSCH) transmitted by the terminal to the base station; A step of receiving the PUSCH based on the random access response from the terminal, The above SIB1 includes information about a candidate set of the number of repetition transmissions including values ​​for one or more numbers of repetition transmissions for performing repeated transmissions of the PUSCH, The random access response includes information indicating one of the values ​​for the number of repetition transmissions included in the candidate set of the number of repetition transmissions, A method characterized in that the above PUSCH is transmitted repeatedly as many times as any one of the above values.

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