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

Abstract

In a wireless communication system, a method for transmitting an uplink channel, performed by a terminal, includes 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) from the base station in response to the preamble, and transmitting the PUSCH to the base station based on the Random Access Response.

Description

[Technical Field]

[0001] This specification relates to wireless communication systems, and more particularly to a method and apparatus for transmitting an uplink channel. [Background technology]

[0002] Following the commercialization of fourth-generation (4G) communication systems, efforts are underway to develop a new fifth-generation (5G) communication system to meet the growing demand for wireless data traffic. 5G communication systems are also referred to as post-LTE systems or new radio (NR) systems, or the next generation of network communication systems beyond 4G. To achieve high data transfer rates, 5G communication systems include systems operating using millimeter-wave (mmWave) bands above 6 GHz, as well as systems operating using frequency bands below 6 GHz to ensure coverage. Consequently, implementation forms at base stations and terminals are still under consideration.

[0003] This increases efficiency and enables communication providers to deliver more data and voice services over a given bandwidth. Therefore, 3GPP NR systems are designed to meet the demand for high-speed data and media transmission, in addition to supporting large volumes of voice. The advantages of NR systems include higher throughput and lower latency on the same platform, support for frequency division duplexing (FDD) and time division duplexing (TDD), and lower operating costs with an extended end-user environment and a simpler architecture. For more efficient data processing, dynamic TDD in NR systems can use methods to vary the number of orthogonal frequency division multiplexing (OFDM) symbols that can be used in uplink and downlink, according to the data traffic direction of the cell user. For example, when a cell's downlink traffic is greater than its uplink traffic, the base station may allocate more downlink OFDM symbols to slots (or subframes). Information about the slot configuration should be transmitted to the terminal.

[0004] To mitigate path loss in the ultra-high frequency band and increase the transmission distance of radio waves, beamforming, massive MIMO, full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, hybrid beamforming (combining analog and digital beamforming), and large-scale antenna technologies are being discussed for 5G communication systems. Furthermore, in order to improve the system network, 5G communication systems are undergoing technological development related to advanced small cells, improved 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, CoMP (coordinated multi-points), and interference cancellation.In addition, 5G systems have seen the development of advanced coding modulation (ACM) methods such as FQAM (hybrid FSK and QAM modulation) and SWSC (sliding window superposition coding), as well as advanced access technologies such as FBMC (filter bank multi-carrier), NOMA (non-orthogonal multiple access), and SCMA (sparse code multiple access).

[0005] On the other hand, in a human-centered connected network where humans generate and consume information, the internet is evolving into the Internet of Things (IoT) network, where information is exchanged between distributed components such as objects. Internet of Everything (IoE) technology is also emerging, combining IoT technology with big data processing technology through connectivity to cloud servers. Implementing IoT requires technological elements such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology. As a result, in recent years, technologies such as sensor networks, machine-to-machine (M2M) communication, and machine-type communication (MTC) have been explored for object-to-object connectivity. In an IoT environment, intelligent internet technology (IT) services can be provided that collect and analyze data generated from connected objects to create new value in human life. Through the integration and blending of existing information technology (IT) with various industries, IoT can be applied to fields such as smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, healthcare, smart home appliances, and advanced medical services.

[0006] Therefore, various attempts are being made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, machine-to-machine (M2M) communication, and machine-type communication (MTC) are implemented using techniques such as beamforming, MIMO, and array antennas. The application of cloud RAN as a big data processing technology described above is an example of the convergence of 5G technology and IoT technology. In general, mobile communication systems are 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 developed to the point where high-speed data services are available. However, due to resource shortages in currently available mobile communication systems and the demand for high-speed services from users, more advanced mobile communication systems are needed. [Overview of the project] [Problems that the invention aims to solve]

[0008] This specification aims to provide a method and apparatus for transmitting an uplink channel in a wireless communication system. [Means for solving the problem]

[0009] This specification provides steps for transmitting an uplink channel in a wireless communication system and apparatus for doing so.

[0010] More specifically, in the step of transmitting an uplink channel in a wireless communication system, the terminal includes 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) for the preamble from the base station; the Random Access Response including information for scheduling a Physical Uplink Shared Channel (PUSCH) to be transmitted by the terminal to the base station; and transmitting the PUSCH to the base station based on the Random Access Response. The SIB1 includes information about a set of repeat transmission count candidates, each containing a value for one or more repeat transmission counts for repeatedly transmitting the PUSCH; the Random Access Response includes information indicating one of the values ​​for one or more repeat transmission counts included in the set of repeat transmission count candidates; and the PUSCH is transmitted repeatedly only by one of these values.

[0011] The terminal further includes the steps of receiving Downlink Control Information (DCI) from a base station, which includes information for scheduling a retransmission PUSCH, and repeatedly transmitting the retransmission PUSCH to the base station based on the DCI, wherein the information for scheduling the retransmission PUSCH includes information regarding the number of repetitions of the retransmission PUSCH, the information regarding the number of repetitions of the retransmission PUSCH is included in the HARQ process number field of the DCI, the retransmission PUSCH is the same as the PUSCH, and the DCI is transmitted by the base station if the base station fails to receive the PUSCH transmitted by the terminal.

[0012] A terminal transmitting an uplink channel in a wireless communication system includes a transceiver and a processor that controls 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, receives 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) to be transmitted by the terminal to the base station, the base station transmits the PUSCH based on the random access response, the SIB1 includes information for a set of repeat transmission count candidates, which includes values ​​for one or more repeat transmission counts for repeated transmission of the PUSCH, the random access response includes information indicating one of the one or more repeat transmission count values ​​included in the set of repeat transmission count candidates, and the PUSCH is transmitted repeatedly by that one value.

[0013] The processor receives downlink control information (DCI) from a base station that includes information for scheduling a PUSCH, and repeatedly transmits the retransmission PUSCH to the base station based on the DCI. The information for scheduling the retransmission PUSCH includes information regarding the number of retransmissions of the PUSCH, and this information is included in the HARQ process number field of the DCI. The retransmission PUSCH is the same as the PUSCH, and the DCI is transmitted by the base station if the base station fails to receive the PUSCH transmitted by the terminal.

[0014] The random access response is characterized by being a Physical Downlink Shared Channel (PDSCH) including an Uplink (UL) grant.

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

[0016] If the MCS field contains information indicating any one of the aforementioned values, then the aforementioned value is indicated by one or more MSBs (Most Significant Bits) of the MCS field.

[0017] If the TPC field contains information indicating any one of the aforementioned values, then the aforementioned value is indicated by one or more LSBs (Least Significant Bits) of the TPC field.

[0018] The SIB1 includes at least one of the information relating to the preamble and a RACH opportunity, and the PUSCH is transmitted over a resource determined based on at least one of the information relating to the preamble and the RACH opportunity.

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

[0020] Each of the values ​​for the one or more repeated transmission counts is characterized by being a power of 2.

[0021] The values ​​for the one or more repeated transmission counts are 1, 2, 4, and 8, respectively.

[0022] The random access response includes a frequency hopping flag indicating whether or not the PUSCH will frequency hop, and the PUSCH performs intra-slot frequency hopping or inter-slot frequency hopping based on one of the values ​​and the frequency hopping flag.

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

[0024] If any one of the above values ​​is greater than 1, the PUSCH will frequency hop between slots if the value of the frequency hopping flag indicates that the PUSCH will frequency hop, and the PUSCH will not frequency hop if the value of the frequency hopping flag indicates that the PUSCH will not frequency hop.

[0025] The random access response further includes information about the resource on which the first repeated transmission of the PUSCH takes place, wherein the information about the resource on which the first repeated transmission of the PUSCH takes place is a slot offset value between the resource that received the random access response and the resource on which the first repeated transmission of the PUSCH takes place; the SIB1 further includes information about the configuration of the TDD, wherein the information about the configuration of the TDD is information about the type of symbols that constitute the slots, wherein the type of symbols is one of a downlink symbol set to be usable for downlink transmission, an uplink symbol set to be usable for uplink transmission, and a flexible symbol that is not set to be a downlink symbol or an uplink symbol; the PUSCH is transmitted repeatedly in slot units, and the resource on which the first repeated transmission of the PUSCH takes place is a resource that is located a number of units away from the resource that received the random access response by the slot offset value.

[0026] The resource on which the first repeated transmission of PUSCH takes place is a flexible slot, and subsequent repeated transmissions of PUSCH take place on an uplink slot, the flexible slot is configured to include at least one of the flexible symbols, and each of the uplink slots is configured to include the uplink symbol.

[0027] A method for receiving an uplink channel in a wireless communication system, 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 for the preamble; the random access response including information for scheduling a physical uplink shared channel (PUSCH) to be transmitted by the terminal to the base station; and receiving the PUSCH from the terminal based on the random access response, wherein the SIB1 includes information about a set of repeat transmission count candidates, each containing a value for one or more repeat transmission counts for repeatedly transmitting the PUSCH; the random access response includes information indicating one of the one or more repeat transmission count values ​​included in the set of repeat transmission count candidates; and the PUSCH is transmitted repeatedly by any one of these values. [Effects of the Invention]

[0028] This specification aims to provide a method for repeatedly transmitting the Msg3 PUSCH of a random access procedure.

[0029] This specification aims to provide a method for frequency hopping between inter-slots of repeatedly transmitted Msg3 PUSCH.

[0030] This specification aims to provide a method for determining the resources to which Msg3 PUSCH is repeatedly transmitted.

[0031] The effects derived from this specification are not limited to those mentioned above, and other effects not mentioned should be clearly understood by those with ordinary skill in the art to which this invention pertains from the following description. [Brief explanation of the drawing]

[0032] [Figure 1]This is a diagram showing an example of a wireless frame structure used in a wireless communication system. [Figure 2] This is a diagram illustrating an example of a downlink (DL) / uplink (UL) slot structure in a wireless communication system. [Figure 3] This is a diagram illustrating the physical channels used in 3GPP systems and typical signal transmission methods using those physical channels. [Figure 4a] This diagram shows the SS / PBCH block for initial cell access in a 3GPP NR system. [Figure 4b] This diagram shows the SS / PBCH block for initial cell access in a 3GPP NR system. [Figure 5a] Figures 5a and 5b show the procedures for transmitting control information and control channels in a 3GPP NR system. [Figure 5b] Figures 5a and 5b show the procedures for transmitting control information and control channels in a 3GPP NR system. [Figure 6] This diagram shows the control resource set (CORESET) that can be transmitted within a physical downlink control channel (PDCCH) in a 3GPP NR system. [Figure 7] This diagram shows a method for constructing a PDCCH search space in a 3GPP NR system. [Figure 8] This is a conceptual diagram illustrating carrier aggregation. [Figure 9] This is a diagram illustrating single-carrier and multi-carrier communication. [Figure 10] This figure shows an example of how cross-carrier scheduling techniques are applied. [Figure 11]These are block diagrams showing the configurations of a terminal and a base station according to one embodiment of the present invention. [Figure 12] This invention provides a method for scheduling a physical uplink sharing channel in the time domain according to one embodiment of the present invention. [Figure 13] This invention describes a method for scheduling a physical uplink sharing channel in the frequency domain according to one embodiment of the present invention. [Figure 14] This shows repeated transmission of a physical uplink sharing channel according to one embodiment of the present invention. [Figure 15] This document describes a scheduling method for a physical uplink control channel according to one embodiment of the present invention. [Figure 16] This shows a repetitive transmission of a physical uplink control channel according to one embodiment of the present invention. [Figure 17] This figure shows the repeated transmission of Msg3 PUSCH according to one embodiment of the present invention. [Figure 18] This figure shows repeated transmission of Msg3 PUSCH using three DMRS according to one embodiment of the present invention. [Figure 19] This figure shows a method for transmitting Msg3 PUSCH using two DMRS according to one embodiment of the present invention. [Figure 20] This figure shows a method for transmitting Msg3 PUSCH using two DMRS according to one embodiment of the present invention. [Figure 21] This figure shows a method for transmitting Msg3 PUSCH using two DMRS according to one embodiment of the present invention. [Figure 22] This figure shows a method for determining the number of modulation symbols for multiplexing uplink control information contained in Msg3 PUSCH according to one embodiment of the present invention. [Figure 23] This figure shows a method for determining the number of modulation symbols for multiplexing uplink control information contained in Msg3 PUSCH according to one embodiment of the present invention. [Figure 24]This figure shows a method for determining the number of modulation symbols for multiplexing uplink control information contained in Msg3 PUSCH according to one embodiment of the present invention. [Figure 25] This figure shows a method for determining the number of modulation symbols for multiplexing uplink control information contained in Msg3 PUSCH according to one embodiment of the present invention. [Figure 26] This figure shows a method for determining the number of modulation symbols for multiplexing uplink control information contained in Msg3 PUSCH according to one embodiment of the present invention. [Figure 27] This figure shows resources that can be used for repeated transmission of Msg3 PUSCH according to one embodiment of the present invention. [Figure 28] This figure shows resources that can be used for repeated transmission of Msg3 PUSCH according to one embodiment of the present invention. [Figure 29] This invention provides a method for determining a frequency hopping method based on the number of repeated transmissions of PUSCH according to one embodiment of the present invention. [Figure 30] This flowchart shows a method by which a terminal according to one embodiment of the present invention transmits Msg3 PUSCH. [Modes for carrying out the invention]

[0033] The terminology used herein adopts common terms that are currently widely used as possible by considering the function of the present invention, but these terms may be modified in accordance with the intent, practice, and emergence of new technologies of those skilled in the art. Furthermore, in certain cases, there are terms that are at the discretion of the applicant, in which case their meanings will be explained in the corresponding descriptive sections of the present invention. It is therefore intended to be clear that the terminology used herein should be analyzed not only on the basis of the names of the terms but also on the substantive meaning of the terms and content throughout this specification.

[0034] Throughout this specification and the following claims, when an element is described as being “connected” to another element, that element may be “directly connected” to the other element, or “electrically connected” to the other element through a third element. Furthermore, unless explicitly stated otherwise, the word “equips” shall be understood as implying the inclusion of the element being described, and not as implying the exclusion of any other element, unless otherwise specified. Moreover, limitations such as “greater than” or “less than” based on a particular threshold may be appropriately replaced in some exemplary embodiments with “greater than” or “less than,” respectively.

[0035] The following technologies can be used in various wireless access systems, including Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Orthogonal Frequency Division Multiple Access (OFDMA), and Single Carrier FDMA (SC-FDMA). CDMA can be implemented by wireless technologies such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA can be implemented by wireless technologies such as Global System for Mobile Communications (GSM®) / General-Purpose Packet Radio Service (GPRS) / GSM® Advanced High-Speed ​​Data Rate (EDGE). OFDMA can be implemented by wireless technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and Advanced UTRA (E-UTRA). UTRA is part of the Universal Mobile Telecommunications System (UMTS). The Third Generation Partnership Project (3GPP) Long-Term Evolution (LTE) is part of Advanced UMTS (EUMTS), which uses Advanced UMTS Terrestrial Radio Access (E-UTRA), and LTE Advanced (A) is an advanced version of 3GPP LTE. 3GPP New Radio (NR) is a system designed separately from LTE / LTE-A to support the requirements of IMT-2020: enhanced mobile broadband (eMBB), ultra-reliable and low latency communication (URLLC), and massive machine type communication (mMTC) services. For clarity, 3GPP NR will be described primarily, but the technical ideas of this invention are not limited to them.

[0036] Unless otherwise specified herein, a base station is defined as a 3GPP NR may refer to a next-generation node B (gNB) as described. Further, unless otherwise specified, the terminal may refer to a user equipment (UE). Hereinafter, for the sake of understanding the description, each content will be separately described as an example, but each example may be used in combination with each other. In the present disclosure, configuring a terminal can represent configuration by a base station. Specifically, the base station can transmit a channel or a signal to the terminal and set the value of an operation of the terminal or a parameter used in a wireless communication system.

[0037] FIG. 1 shows an example of a wireless frame structure used in a wireless communication system.

[0038] Referring to FIG. 1, a wireless frame (or radio frame) used in a 3GPP NR system may have a length of 10 ms (Δf max N f / 100)*T c ). In addition, the wireless frame may include 10 subframes (SF: subframe) of equal size. In this specification, Δf max = 480 * 10 3 Hz, N f = 4096, T c = 1 / (Δf ref * N f,ref ), Δf ref = 15 * 10 3 Hz, and N f,ref = 2048. Numbers from 0 to 9 may be respectively assigned to the 10 subframes within one wireless frame. Each subframe may have a length of 1 ms and may include one or more slots according to a subcarrier spacing. More specifically, in a 3GPP NR system, the subcarrier spacing that can be used is 15 * 2 μ kHz, and μ can have values of μ = 0, 1, 2, 3, 4 as a subcarrier spacing configuration. That is, 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 24 kHz can be used for the subcarrier spacing. One subframe having a length of 1 ms is 2 μIt may contain 2 slots. In this case, the length of each slot is 2 -μ It is ms. 2 within one subframe μ Each slot has 0 to 2 μ Numbers up to -1 may be assigned. In addition, each slot within a single wireless frame can be assigned from 0 to 10*2. μ A number up to -1 may be assigned. Time resources can be distinguished by at least one of the following: wireless frame number (also called wireless frame index), subframe number (also called subframe index), and slot number (or slot index).

[0039] Figure 2 shows an example of a downlink (DL) / uplink (UL) slot structure in a wireless communication system. In particular, Figure 2 shows the resource grid structure of a 3GPP NR system.

[0040] Specifically, Figure 2 shows the structure of the resource grid in a 3GPP NR system. There is one resource grid per antenna port. Referring to Figure 2, a slot contains multiple orthogonal frequency division multiplexing (OFDM) symbols in the time domain and multiple resource blocks (RBs) in the frequency domain. An OFDM symbol also means one symbol section. Unless otherwise specified, an OFDM symbol is sometimes simply called a symbol. One RB contains 12 consecutive subcarriers in the frequency domain. Referring to Figure 2, the signal transmitted from each slot is N size,μ grid,x *N RB sc Book subcarriers and N slot symb It may be represented by a resource grid containing n OFDM symbols, where x=DL when the signal is a DL signal and x=UL when the signal is a UL signal. size,μ grid,x This represents the number of resource blocks (RBs) according to the subcarrier interval, which is a component of μ (where x is DL or UL), and Nslot symb This represents the number of OFDM symbols in the slot. RB sc N is the number of subcarriers that make up one RB. RB sc = 12. OFDM symbols are sometimes called cyclic shift OFDM (CP-OFDM) symbols or discrete Fourier transform spread OFDM (DFT-s-OFDM) symbols, depending on the multiple access scheme.

[0041] The number of OFDM symbols contained in a single slot may vary depending on the length of the cyclic prefix (CP). For example, with a normal CP, a single slot may contain 14 OFDM symbols, while with an extended CP, a single slot may contain 12 OFDM symbols. In certain embodiments, the extended CP may be used only at a 60 kHz subcarrier interval. In Figure 2, for illustrative purposes, a single slot is configured using 14 OFDM symbols as an example, but embodiments of this disclosure may similarly apply to slots with different numbers of OFDM symbols. Referring to Figure 2, each OFDM symbol has N in the frequency domain. size,μ grid,x *N RB sc This includes subcarriers. Subcarrier types 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).

[0042] One RB is N in the frequency domain. RB sc(For example, 12) can be defined by consecutive subcarriers. For reference, a resource composed of one OFDM symbol and one subcarrier is sometimes called a resource element (RE) or tone. Thus, one RB is N slot symb *N RB sc It can be composed of individual resource elements. Each resource element in the resource grid can be uniquely defined by a pair of indices (k,l) within a single slot, where k ranges from 0 to N in the frequency domain. size,μ grid,x *N RB sc It can be an index that can be assigned up to -1, and l is from 0 to N in the time domain. slot symb It can be an index that can be allocated down to -1.

[0043] For a UE to receive signals from or transmit signals to a base station, the UE's time / frequency may be synchronized with the base station's time / frequency. This is because, when the base station and UE are synchronized, the UE can determine the time and frequency parameters necessary to demodulate the DL signal and transmit the UL signal at the appropriate time.

[0044] Each symbol in a radio frame used in time-division duplexing (TDD), i.e., in an unpaired spectrum, may consist of at least one of DL symbols, UL symbols, and flexible symbols. A radio frame used as a DL carrier in frequency-division duplexing (FDD), i.e., in a paired spectrum, may consist of DL symbols or flexible symbols, and a radio frame used as a UL carrier may consist of UL symbols or flexible symbols. DL symbols allow for DL ​​transmission but not UL transmission. UL symbols allow for UL transmission but not DL transmission. Flexible symbols may be determined to be used as DL or UL depending on the signal.

[0045] Information about each symbol type, i.e., information representing one of DL symbols, UL symbols, and flexible symbols, may be provided using cell-specific or common radio resource control (RRC) signals. In addition, information about each symbol type may be provided using UE-specific or dedicated RRC signals. The base station notifies the following using cell-specific RRC signals: i) the duration of the cell-specific slot configuration, ii) the number of slots with only DL symbols from the beginning of the cell-specific slot configuration period, iii) the number of DL symbols from the first symbol of the slot immediately following a slot with only DL symbols, iv) the number of slots with only UL symbols from the end of the cell-specific slot configuration period, and v) the number of UL symbols from the last symbol of the slot immediately preceding a slot with only UL symbols. Here, a flexible symbol is a symbol that is not configured using either a UL symbol or a DL symbol.

[0046] When information about the symbol type is constructed using UE-specific RRC signals, the base station may signal in the cell-specific RRC signals whether a flexible symbol is a DL symbol or a UL symbol. In this case, the UE-specific RRC signals cannot change a DL symbol or UL symbol constructed using the cell-specific RRC signals to another symbol type. The UE-specific RRC signals are N for each corresponding slot per slot. slot symb The number of DL symbols among the symbols, and the N of the corresponding slots. slot symbThe number of UL symbols among the symbols can be signaled. In this case, the DL symbols of a slot can be continuously configured using the first symbol to the i-th symbol of the slot. In addition, the UL symbols of a slot can be continuously configured using the j-th symbol to the last symbol of the slot (where i < j). Among the symbols in a slot, the symbol that is not configured using either the UL symbol or the DL symbol is a flexible symbol.

[0047] The type of symbol consisting of the above RRC signal is referred to as a semi-static DL / UL configuration. In the semi-static DL / UL configuration consisting of the above-described RRC signal, a flexible symbol is indicated as a downlink symbol, an uplink symbol, or a flexible symbol via the dynamic SFI (slot format information) transmitted on the physical downlink control channel (PDCCH). At this time, a downlink symbol or an uplink symbol consisting of an RRC signal is not changed to another symbol type. Table 1 exemplifies the dynamic SFI indicated by the base station to the terminal. <000035%>

Table 1

[0049] In Table 1, D indicates a downlink symbol, U indicates an uplink symbol, and X indicates a flexible symbol. As shown in Table 1, a maximum of two DL / UL switchings are allowed in one slot.

[0050] Figure 3 is a diagram for explaining a physical channel used in a 3GPP system (e.g., NR) and a general signal transmission method using the corresponding physical channel.

[0051] When the UE is powered on or camp-on to a new cell, the UE performs an initial cell discovery (S101). Specifically, the UE may synchronize with the base station during the initial cell discovery. To this end, the UE may receive primary synchronization signals (PSS) and secondary synchronization signals (SSS) from the base station to synchronize with the base station and obtain information such as the cell ID. Subsequently, the UE may receive physical broadcast channels from the base station and obtain broadcast information in the cell.

[0052] Upon completion of the initial cell discovery, the UE receives the physical downlink control channel (PDCCH) and the physical downlink shared channel (PDSCH) according to the information in the PDCCH. As a result, the UE can obtain more specific system information than the system information obtained through the initial cell discovery (S102). Here, the system information obtained by the UE is the cell-common system information necessary for the UE to operate correctly at the physical layer in the Radio Resource Control (RRC), and is also called remaining system information or system information block (SIB) 1.

[0053] If the terminal first accesses the base station or if there are no radio resources for signal transmission (if the terminal is in RRC_IDLE mode), the terminal performs a random access process to the base station in steps S103 to S106. First, the terminal transmits a preamble via a physical random access channel (PRACH) in step S103, and receives a random access response (RAR) message for the preamble from the base station via the PDCCH and corresponding PDSCH in step S104. In this case, the preamble in steps S103 and S104 is described as message 1 (Msg1), and the random access response is described as a response message or message 2 (Msg2). If the terminal receives a valid random access response, the terminal transmits data including its own identifier to the base station via the physical uplink sharing channel (PUSCH) indicated by the uplink grant transmitted from the base station via the PDCCH or PDSCH in step S105. In this case, the data including its own identifier in step S105 and the PUSCH containing the data are described as message 3 (Msg3). Furthermore, the PUSCH containing the aforementioned data is described in message 3PUSCH (Msg3 PUSCH). Next, the terminal waits to receive PDCCH as an instruction from the base station to resolve the collision. When the terminal successfully receives PDCCH via its own identifier and receives the corresponding PDSCH, S106, the random access process ends. At this time, the PDCCH and PDSCH in S106 are described in message 4 (Msg4). During the random access process, the terminal obtains terminal-specific system information at the RRC layer, which is necessary for the terminal to operate correctly at the physical layer. Once the terminal obtains terminal-specific system information from the RRC layer, the terminal enters RRC_CONNECTED mode.

[0054] The RRC layer is used for message generation and management for control between terminals and the Radio Access Network (RAN). More specifically, base stations and terminals can use the RRC layer to broadcast cell system information necessary for all terminals in a cell, manage the transmission of paging messages, manage mobility and handover, report and control terminal measurements, and manage storage including terminal capability management and equipment management. In general, the update of signals transmitted in the RRC layer (hereinafter referred to as RRC signals) is longer than the transmission time interval (TTI) in the physical layer, so RRC signals can be maintained unchanged over long periods.

[0055] After the procedure described above, the UE receives the PDCCH / PDSCH (S107) and transmits the physical uplink shared channel (PUSCH) / physical uplink control channel (PUCCH) as a general UL / DL signal transmission procedure (S108). Specifically, the UE may receive downlink control information (DCI) through the PDCCH. The DCI may include control information such as resource allocation information for the UE. The format of the DCI may also vary depending on the intended use. The uplink control information (UCI) that the UE transmits to the base station through the UL includes DL / UL ACK / NACK signals, a channel quality indicator (CQI), a precoding matrix index (PMI), a rank indicator (RI), etc. Here, the CQI, PMI, and RI may be included in the channel state information (CSI). In a 3GPP NR system, the UE may transmit control information such as the HARQ-ACK and CSI described above via PUSCH and / or PUCCH.

[0056] Figures 4a and 4b show the SS / PBCH block for initial cell access in the 3GPP NR system.

[0057] When power is turned on or when a new cell is desired, the UE may obtain time and frequency synchronization with the cell and execute an initial cell discovery procedure. During the cell discovery procedure, the UE obtains the physical cell identification information N of the cell. cell ID This can be detected. To this end, the UE can receive synchronization signals from the base station, such as a primary synchronization signal (PSS) and a secondary synchronization signal (SSS), and synchronize with the base station. In this case, the UE can obtain information such as cell identification information (ID).

[0058] The synchronization signal (SS) is described in more detail with reference to Figure 4a. Synchronization signals can be classified into PSS and SSS. PSS can be used to obtain time-domain and / or frequency-domain synchronization, such as OFDM symbol synchronization and slot synchronization. SSS can be used to obtain frame synchronization and cell group ID. Referring to Figure 4a and Table 2, an SS / PBCH block can be constructed using 20 consecutive RBs (=240 subcarriers) in the frequency axis and 4 consecutive OFDM symbols in the time axis. In this case, within the SS / PBCH block, the PSS is transmitted in the first OFDM symbol, and the SSS is transmitted in the third OFDM symbol through subcarriers 56 to 182. Here, the smallest subcarrier index in the SS / PBCH block is numbered starting from 0. In the first OFDM symbol in which PSS is transmitted, the base station does not transmit signals through the remaining subcarriers, namely subcarriers 0-55 and 183-239. In addition, in the third OFDM symbol in which SSS is transmitted, the base station does not transmit signals through subcarriers 48-55 and 183-191. The base station transmits the physical broadcast channel (PBCH) through the remaining REs in the SS / PBCH block, excluding the signals mentioned above.

[0059] [Table 2]

[0060] SS allows a total of 1008 unique physical layer cell IDs to be grouped into 336 physical layer cell identifier groups, each group containing three unique identifiers through three PSS and SSS combinations, such that each physical layer cell ID is part of only one physical layer cell identifier group. Thus, physical layer cell ID N cellID =3N (1) ID +N (2) ID This represents an index N ranging from 0 to 335, indicating a physical layer cell identifier group. (1) ID , and an index N ranging from 0 to 2, indicating the physical layer identifier within the physical layer cell identifier group. (2) ID This can be uniquely defined by the following. The UE can detect the PSS and identify one of the three unique physical layer identifiers. In addition, the UE can detect the SSS and identify one of the 336 physical layer cell IDs associated with the physical layer identifier. In this case, the PSS sequence d PSS (n) is as follows:

[0061]

number

[0062] Furthermore, the SSS series d SSS (n) is as follows:

number

[0063] A radio frame with a length of 10 ms can be divided into two half-frames with a length of 5 ms. Referring to Figure 4b, the slot in which the SS / PBCH block is transmitted within each half-frame is described. The slot in which the SS / PBCH block is transmitted may be any one of cases A, B, C, D, and E. In case A, the subcarrier spacing is 15 kHz, and the start of the SS / PBCH block is the ({2,8}+14*n)th symbol. In this case, n=0 or 1 at carrier frequencies below 3 GHz. In addition, n may be 0, 1, 2, or 3 at carrier frequencies above 3 GHz and below 6 GHz. In case B, the subcarrier spacing is 30 kHz, and the start of the SS / PBCH block is {4,8,16,20}+28*n. In this case, n=0 at carrier frequencies below 3 GHz. In addition, n may be 0 or 1 at carrier frequencies above 3 GHz and below 6 GHz. In Example C, the subcarrier spacing is 30 kHz, and the start of the SS / PBCH block is the ({2,8}+14*n)th symbol. In this case, n=0 or 1 at carrier frequencies below 3 GHz. In addition, n may be 0, 1, 2, or 3 at carrier frequencies above 3 GHz and below 6 GHz. In Example D, the subcarrier spacing is 120 kHz, and the start of the SS / PBCH block is the ({4,8,16,20}+28*n)th symbol. In this case, n is 0, 1, 2, 3, 5, 6, 7, 8, 10, 11, 12, 13, 15, 16, 17, or 18 at carrier frequencies above 6 GHz. In Example E, the subcarrier spacing is 240 kHz, and the start of the SS / PBCH block is the ({8,12,16,20,32,36,40,44}+56*n)th symbol. In this case, for carrier frequencies above 6 GHz, n = 0, 1, 2, 3, 5, 6, 7, 8.

[0064] Figures 5a and 5b illustrate the procedures for transmitting control information and control channels in a 3GPP NR system. Referring to Figure 5a, a base station may add a cyclic redundancy check (CRC) masked (e.g., by XOR operation) using a radio network temporary identifier (RNTI) to the control information (e.g., downlink control information (DCI)) (S202). The base station may scramble the CRC using an RNTI value determined according to the purpose / target of each piece of control information. A common RNTI used by one or more UEs may include at least one of the following: system information RNTI (SI-RNTI), paging RNTI (P-RNTI), random access RNTI (RA-RNTI), and transmit power control RNTI (TPC-RNTI). In addition, UE-specific RNTIs may include at least one of the following: cell temporary RNTI (C-RNTI) and CS-RNTI. Subsequently, the base station may perform channel coding (e.g., polar coding) (S204) and then perform rate matching according to the amount of resources used for PDCCH transmission (S206). The base station may then multiplex the DCI based on a control channel element (CCE)-based PDCCH structure (S208). In addition, the base station may apply additional processes such as scrambling, modulation (e.g., QPSK), and interleaving to the multiplexed DCI (S210), and then map the DCI to the resources to be transmitted. A CCE is the basic resource unit for a PDCCH, and one CCE may contain multiple (e.g., six) resource element groups (REGs). One REG may consist of multiple (e.g., twelve) REs. The number of CCEs used for one PDCCH may be defined as the aggregation level.In 3GPP NR systems, aggregation levels 1, 2, 4, 8, or 16 may be used. Figure 5b is a diagram relating CCE aggregation levels and PDCCH multiplexing, showing the type of CCE aggregation level used for a single PDCCH and the CCE transmitted within the control area accordingly.

[0065] Figure 6 shows the control resource set (core set) that a physical downlink control channel (PDCCH) can transmit within in a 3GPP NR system.

[0066] A coreset is a time-frequency resource in which PDCCHs, i.e., control signals for the UE, are transmitted. In addition, a search space, which will be described later, may be mapped to a coreset. Thus, a UE may monitor a time-frequency domain designated as a coreset, rather than monitoring all frequency bands for PDCCH reception, and can decode the PDCCH mapped to the coreset. A base station may configure one or more coresets per cell for the UE. A coreset may be configured using up to three consecutive symbols on the time axis. In addition, a coreset may be configured in units of six consecutive PRBs on the frequency axis. In the embodiment of Figure 6, coreset #1 is configured using consecutive PRBs, and coresets #2 and #3 are configured using non-contiguous PRBs. A coreset may be placed in any symbol within a slot. For example, in the embodiment of Figure 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. Figure 7 shows a method for setting up the PUCCH search space in the 3GPP NR system.

[0067] To transmit a PDCCH to a UE, each core set may have at least one search space. In embodiments of this disclosure, the search space is a set of all time-frequency resources through which a UE's PDCCH can be transmitted (hereinafter, PDCCH candidates). The search space may include a common search space that all UEs of 3GPP NR are required to search in common, and terminal-specific or UE-specific search spaces that a particular UE is required to search. In the common search space, a UE may monitor a PDCCH that is set up to be searched in common by all UEs in a cell belonging to the same base station. In addition, UE-specific search spaces may be set up per UE so that a UE monitors a PDCCH allocated to each UE at different search space locations according to the UE. In the case of UE-specific search spaces, the search spaces between UEs may partially overlap or be allocated due to the limited control area through which a PDCCH is allocated. Monitoring a PDCCH involves blind decoding to find PDCCH candidates in the search space. When blind decoding is successful, it may be expressed that the PDCCH has been (successfully) detected / received, and when blind decoding fails, it may be expressed that the PDCCH has not been detected / received, or has not been successfully detected / received.

[0068] For the sake of explanation, a PDCCH scrambled using a group-common (GC) RNTI previously known to one or more UEs to send DL control information to one or more UEs is called a group-common (GC) PDCCH or common PDCCH. In addition, a PDCCH scrambled using a terminal-specific RNTI already known to a particular UE to send UL scheduling information or DL ​​scheduling information to a particular UE is called a UE-specific PDCCH. Common PDCCHs may be contained within a common search space, and UE-specific PDCCHs may be contained within a common search space or within a UE-specific PDCCH.

[0069] A base station may signal to each UE or UE group via the PDCCH about information relating to resource allocation for the transmission channels, namely the paging channel (PCH) and the downlink-shared channel (DL-SCH) (i.e., DL permission), or information relating to resource allocation for the uplink-shared channel (UL-SCH) and Hybrid Automatic Retransmission Request (HARQ) (i.e., UL permission). The base station may transmit PCH transport blocks and DL-SCH transport blocks via the PDSCH. The base station may transmit data, excluding certain control information or certain service data, via the PDSCH. In addition, UEs may receive data, excluding certain control information or certain service data, via the PDSCH.

[0070] A base station may include information in a PDCCH about where the UE(s) PDSCH data will be transmitted to and how the corresponding UE will receive and decode the PDSCH data, and may transmit such a PDCCH. For example, suppose a DCI transmitted on a particular PDCCH is CRC masked using an RNTI named "A", and the DCI indicates that the PDSCH is allocated to a radio resource (e.g., frequency location) named "B", and indicates transmission format information (e.g., transport block size, modulation scheme, coding information, etc.) named "C". A UE monitors the PDCCH using the RNTI information it possesses. In this case, if there is a UE performing blind decoding of the PDCCH using the RNTI of "A", that UE will receive the PDCCH and, through the received PDCCH information, receive the PDSCH indicated by "B" and "C".

[0071] Table 3 shows one embodiment of a physical uplink control channel (PUCCH) used in a wireless communication system.

[0072] [Table 3]

[0073] PUCCH can be used to transmit the following UL control information (UCI):

[0074] - Scheduling Request (SR): Information used to request UL-SCH resources.

[0075] - HARQ-ACK: A response to the PDCCH (indicating DL SPS release) and / or to the DL transport block (TB) on the PDSCH. HARQ-ACK indicates whether information transmitted on the PDCCH or PDSCH has been received. HARQ-ACK responses include positive ACK (simply ACK), negative ACK (hereinafter, NACK), discontinuous transmission (DTX), or NACK / DTX. Here, the term HARQ-ACK is used in conjunction with HARQ-ACK / NACK and ACK / NACK. Generally, ACK may be represented by a bit value of 1, and NACK may be represented by a bit value of 0.

[0076] - Channel Status Information (CSI): Feedback information on the DL channel. The UE generates it based on the CSI reference signal (RS) transmitted by the base station. Multi-input multiple-output (MIMO) related feedback information includes a rank indicator (RI) and a precoding matrix indicator (PMI). The CSI can be divided into CSI part 1 and CSI part 2 according to the information indicated by the CSI.

[0077] The 3GPP NR system may use five PUCCH formats to support various service scenarios, channel environments, and frame structures.

[0078] PUCCH format 0 is a format capable of transmitting 1-bit or 2-bit HARQ-ACK information or SR. PUCCH format 0 can be transmitted through one or two OFDM symbols on the time axis and one RB on the frequency axis. When PUCCH format 0 is transmitted through two OFDM symbols, the same sequence on the two symbols may be transmitted through different RBs. In this case, the sequence may be a sequence that has been cyclically shifted (CS) from the base sequence used in PUCCH format 0. Through this, the UE can obtain frequency diversity gain. Specifically, the terminal is M bit Bit UCI(M bit =1 or 2) The cyclic shift (CS) value m cs It is possible to determine this. Also, a basic series of length 12 can be determined by a defined CS value m cs Based on this, a cyclically shifted sequence can be mapped to 12 REs, each consisting of one OFDM symbol and one RB, and transmitted. The number of cyclic shifts available to the terminal is 12, and M bit If = 1, then the 1-bit UCI 0 and 1 can be mapped to two cyclically shifted sequences, respectively, where the difference in cyclic shift values ​​is 6. Also, M bit If = 2, the 2-bit UCIs 00, 01, 11, and 10 can each be mapped to four cyclically shifted sequences, each with a cyclic shift value difference of 3.

[0079] PUCCH format 1 transmits 1-bit or 2-bit HARQ-ACK information or SR. PUCCH format 1 is transmitted via a continuous sequence of OFDM symbols on the time axis and a single PRB on the frequency axis. Here, the number of OFDM symbols occupied by PUCCH format 1 is one of 4 to 14. For more details, see M bit UCI with =1 is modulated by BPSK. The terminal is M bitThe UCI, which is equal to 2, is modulated using QPSK (quadrature phase shift keying). A signal is obtained by multiplying the modulated complex valued symbol d(0) by a sequence of length 12. The terminal transmits the obtained signal by spreading it with time-axis OCC (orthogonal cover code) to the even-numbered OFDM symbols to which PUCCH format 1 is assigned. The maximum number of different terminals that can be multiplexed with the same RB is determined by the length of the OCC used in PUCCH format 1. The DMRS (demodulation reference signal) is spread with OCC and mapped to the odd-numbered OFDM symbols of PUCCH format 1.

[0080] PUCCH format 2 can deliver UCIs of more than 2 bits. PUCCH format 2 can be transmitted through one or two OFDM symbols on the time axis and one or more RBs on the frequency axis. When PUCCH format 2 is transmitted through two OFDM symbols, the sequences transmitted through the two OFDM symbols in different RBs may be the same as each other. Here, the sequence is a plurality of modulated complex value symbols d(0),...,d(M symbol -1) is acceptable. Here, M symbol is M bit It may be / 2. Through this, the UE can obtain frequency diversity gain. More specifically, M bit Bit UCI(M bit >2) is bit-level scrambled, QPSK modulated, and mapped to one or two OFDM symbols as RBs, where the number of RBs can be one between 1 and 16. PUCCH format 3 or PUCCH format 4 can deliver UCIs of more than 2 bits. PUCCH format 3 or PUCCH format 4 can be transmitted through a sequence of OFDM symbols on the time axis and one PRB on the frequency axis. The number of OFDM symbols occupied by PUCCH format 3 or PUCCH format 4 may be one of 4 to 14. Specifically, the UE uses π / 2-2 phase shift keying (BPSK) or QPSK for M bit Modulate the bit UCI (Mbit>2) to obtain the complex value symbol d(0)~d(M symb -1) is generated. Here, when using π / 2-BPSK, M symb =M bit And when using QPSK, M symb =M bit The value is / 2. The UE does not have to apply block-based spread to PUCCH format 3. However, the UE may apply block-based spread to one RB (i.e., 12 subcarriers) using a PreDFT-OCC of length 12 such that PUCCH format 4 may have a multiplexing capacity of 2 or 4. The UE performs transmit precoding (or DFT precoding) on ​​the spread signal and maps it to each RE to transmit the spread signal.

[0081] In this case, the number of RBs occupied by PUCCH format 2, PUCCH format 3, or PUCCH format 4 may be determined according to the length and maximum code rate of the UCI transmitted by the UE. When the UE uses PUCCH format 2, the UE may transmit HARQ-ACK information and CSI information together through PUCCH. If the number of RBs that the UE can transmit is greater than the maximum number of RBs that PUCCH format 2, PUCCH format 3, or PUCCH format 4 can use, the UE may transmit only the remaining UCI information without transmitting some of the UCI information, according to the priority of the UCI information.

[0082] PUCCH format 1, PUCCH format 3, or PUCCH format 4 may be configured through an RRC signal to indicate frequency hopping within a slot. When frequency hopping is configured, the index of the RB to be frequency-hopped may be configured using the RRC signal. When PUCCH format 1, PUCCH format 3, or PUCCH format 4 is transmitted through N OFDM symbols on the time axis, the first hop may have floor(N / 2) OFDM symbols, and the second hop may have ceil(N / 2) OFDM symbols.

[0083] PUCCH format 1, PUCCH format 3, or PUCCH format 4 may be configured to be transmitted repeatedly in multiple slots. In this case, the number K of slots in which the PUCCH is transmitted repeatedly may be determined by the RRC signal. The repeatedly transmitted PUCCH must begin at a fixed position OFDM symbol in each slot and must be of a constant length. When one of the OFDM symbols in a slot in which the UE is to transmit the PUCCH is indicated as a DL symbol by the RRC signal, the UE does not have to transmit the PUCCH in the corresponding slot and may delay the transmission of the PUCCH until the next slot in which it is to be transmitted.

[0084] On the other hand, in a 3GPP NR system, a terminal can transmit and receive using a bandwidth smaller than or equal to the carrier (or cell) bandwidth. To this end, a terminal may have a bandwidth part (BWP) consisting of a contiguous portion of the carrier bandwidth. A terminal operating by TDD or in an unpaired spectrum may have up to four DL / UL BWP pairs per carrier (or cell). A terminal can also activate one DL / UL BWP pair. A terminal operating by FDD or in a paired spectrum may have up to four DL BWPs per downlink carrier (or cell) and up to four UL BWPs per uplink carrier (or cell). A terminal can activate one DL BWP and one UL BWP for each carrier (or cell). A terminal does not need to receive or transmit using time-frequency resources other than the activated BWPs. Activated BWPs can be called active BWPs.

[0085] A base station can indicate to a terminal which of the configured BWPs (bandwidth points) are activated using downlink control information (DCI). The BWP indicated in the DCI is activated, and the other configured BWPs are deactivated. In a carrier (or cell) operating in TDD mode, the base station may include a bandwidth part indicator (BPI) indicating the activated BWP in the DCI that schedules a PDSCH or PUSCH to change the terminal's DL / UL BWP pair. The terminal can receive the DCI that schedules the PDSCH or PUSCH and identify the activated DL / UL BWP pair based on the BPI. In a downlink carrier (or cell) operating in FDD mode, the base station may include a BPI indicating the activated BWP in the DCI that schedules a PDSCH to change the terminal's DL BWP. In an uplink carrier (or cell) operating in FDD mode, the base station may include a BPI indicating the activated BWP in the DCI that schedules a PUSCH to change the terminal's UL BWP.

[0086] Figure 8 is a conceptual diagram illustrating career integration.

[0087] To achieve this, the UE uses multiple frequency blocks or cells (in a logical sense) composed of UL resources (or component carriers) and / or DL ​​resources (or component carriers) as one large logical frequency band. A single component carrier may also be referred to as a primary cell (PCell), secondary cell (SCell), or primary SCell (PScell). However, for the sake of explanation, the term "component carrier" will be used below.

[0088] Referring to Figure 8, as an example of a 3GPP NR system, the overall system bandwidth may include up to 16 component carriers, each component carrier may have a bandwidth of up to 400 MHz. A component carrier may include one or more physically continuous subcarriers. Although Figure 8 shows that each component carrier has the same bandwidth, this is just an example, and each component carrier may have a different bandwidth. Also, although each component carrier is shown as adjacent to each other on the frequency axis, the diagram is shown in a logical concept, and each component carrier may be physically adjacent to each other or separated from each other.

[0089] A different center frequency may be used for each component carrier. Alternatively, a single common center frequency may be used for physically adjacent component carriers. In the embodiment shown in Figure 8, assuming that all component carriers are physically adjacent, center frequency A may be used for all component carriers. Furthermore, assuming that the component carriers are not physically adjacent to each other, center frequencies A and B may be used for each component carrier.

[0090] When the entire system bandwidth is extended by carrier aggregation, the frequency bandwidth used for communication with each UE can be defined in units of component carriers. UE A may use the entire system bandwidth of 100 MHz and communicate using all five component carriers. UEs B1-B5 may use only 20 MHz bandwidth and communicate using one component carrier. UEs C1 and C2 may use 40 MHz bandwidth and communicate using two component carriers each. The embodiment in Figure 8 shows that UEC1 uses two non-adjacent component carriers and UEC2 uses two adjacent component carriers.

[0091] Figure 9 illustrates single-carrier and multi-carrier communication. Specifically, Figure 9(a) shows a single-carrier subframe structure, and Figure 9(b) shows a multi-carrier subframe structure.

[0092] Referring to Figure 9(a), in FDD mode, a typical wireless communication system may perform data transmission or data reception through one DL band and one UL band, corresponding to these. In another specific embodiment, in TDD mode, the wireless communication system may divide a radio frame in the time domain into UL time units and DL time units, and perform data transmission or data reception through the UL / DL time units. Referring to Figure 9(b), three 20 MHz component carriers (CCs) may be aggregated into UL and DL, respectively, so that a 60 MHz bandwidth can be supported. Each CC may or may not be adjacent to each other in the frequency domain. Figure 9(b) shows an example where the bandwidths of the UL CC and DL CC are the same and symmetric, but the bandwidth of each CC may be determined independently. In addition, asymmetric carrier aggregation with different numbers of UL CCs and DL CCs is possible. DL / UL CCs allocated / configured to a particular UE through RRC are sometimes called the serving DL / UL CCs of that particular UE.

[0093] A base station may communicate with a UE by activating some or all of the UE's serving CCs, or by deactivating some of the CCs. The base station may change which CCs are to be activated / deactivated, and may change the number of CCs to be activated / deactivated. If the base station allocates CCs available to a UE as cell-specific or UE-specific, at least one of the allocated CCs may be deactivated unless the CC allocation to the UE is completely reconfigured or the UE is handed over. The CC that is not deactivated by the UE is called the Primary CC (PCC) or Primary Cell (PCell), and the CC that the base station can freely activate / deactivate is called the Secondary CC (SCC) or Secondary Cell (SCell).

[0094] On the other hand, 3GPP NR uses the concept that a cell manages radio resources. A cell is defined as a combination of DL resources and UL resources, i.e., a combination of DL CC and UL CC. A cell may consist of DL resources only, or a combination of DL resources and UL resources. When carrier aggregation is supported, the coordination between the carrier frequencies of DL resources (i.e., DL CC) and UL resources (i.e., UL CC) may be indicated by system information. The carrier frequency refers to the center frequency of each cell or CC. A cell corresponding to a PCC is called a PCell, and a cell corresponding to an SCC is called a SCell. The carrier corresponding to a PCell in DL is a DL PCC, and the carrier corresponding to a PCell in UL is a UL PCC. Similarly, the carrier corresponding to a SCell in DL is a DL SCC, and the carrier corresponding to a SCell in UL is a UL SCC. Depending on the UE capability, a serving cell may consist of one PCell and zero or more SCells. If a UE is in the RRC_CONNECTED state but is not configured for or does not support carrier aggregation, it will have only one serving cell configured using only PCells.

[0095] As described above, the term "cell" as used in carrier aggregation is distinct from the term "cell" which refers to several geographical areas where communication services are provided by a single base station or antenna group. That is, a single component carrier may also be called a scheduling cell, scheduled cell, primary cell (PCell), secondary cell (SCell), or primary SCell (PScell). However, in order to distinguish between cells referring to several geographical areas and cells in carrier aggregation, in this disclosure, cells in carrier aggregation are referred to as CCs, and cells in geographical areas are referred to as cells.

[0096] Figure 10 shows an example where the cross-carrier scheduling technique is applied. When cross-carrier scheduling is set up, a control channel transmitted through the 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 set up, and DL / UL permissions transmitted within the PDCCH area of ​​the scheduling cell schedule the PDSCH / PUSCH of the scheduled cell. That is, a search area for multiple component carriers exists within the PDCCH area of ​​the scheduling cell. A PCell can essentially be a scheduling cell, and a particular SCell may be designated as a scheduling cell by a higher layer.

[0097] In the embodiment shown in Figure 10, it is assumed that three DL CCs are merged. Here, it is assumed that DL component carrier #0 is a DL PCC (or PCell), and DL component carriers #1 and #2 are DL SCCs (or SCells). In addition, it is assumed that the DL PCC is configured as a PDCCH that monitors CCs. When 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 send only a PDCCH to schedule its PDSCH without using 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 UE-specific (or UE group-specific or cell-specific) upper-layer signaling, CIF is enabled, and a particular CC (e.g., DL PCC) may send not only a PDCCH to schedule the PDSCH of DL CC A using CIF, but also a PDCCH to schedule the PDSCH of another CC (cross-carrier scheduling). On the other hand, PDCCH is not transmitted within another DL CC. Therefore, depending on whether cross-carrier scheduling is configured for the UE, the UE will either monitor a PDCCH without a CIF to receive a self-carrier scheduled PDSCH, or monitor a PDCCH with a CIF to receive a cross-carrier scheduled PDSCH.

[0098] On the other hand, Figures 9 and 10 show the subframe structure of a 3GPP LTE-A system, and the same or a similar configuration may be applied to a 3GPP NR system. However, in a 3GPP NR system, the subframes in Figures 9 and 10 may be replaced with slots.

[0099] Figure 11 is a block diagram showing the configurations of a terminal and a base station according to one embodiment of the present disclosure.

[0100] In the embodiments of this disclosure, the terminal can be embodied as various wireless communication devices or computer devices that ensure portability and mobility. The terminal may also be referred to as UE (User Equipment), STA (Station), MS (Mobile Subscriber), etc. Furthermore, in the embodiments of this disclosure, the base station may control and manage cells (e.g., macrocells, femtocells, picocells, etc.) corresponding to the service area and have functions such as signal transmission, channel assignment, channel monitoring, self-diagnosis, and relaying. The base station may also be referred to as gNB (next Generation Node B) or AP (Access Point), etc.

[0101] As shown in the figures, a terminal 100 according to one embodiment of the present disclosure may include a processor 110, a communication module 120, a memory 130, a user interface 140, and a display unit 150.

[0102] First, the processor 110 can execute various instructions or programs and process data inside the terminal 100. Furthermore, the processor 110 can control the overall operation of the terminal 100, including each unit, and control data transmission and reception between units. Here, the processor 110 may be configured to perform the operations described in the embodiments of this disclosure. For example, the processor 110 can receive slot configuration information, determine the slot configuration based on this information, and perform communication according to the determined slot configuration.

[0103] Next, the communication module 120 may be an integrated module that performs wireless communication using a wireless communication network and wireless LAN connection using a wireless LAN. For this purpose, the communication module 120 may be equipped with multiple network interface cards (NICs), such as cellular communication interface cards 121 and 122 and an unlicensed band communication interface card 123, either internally or externally. In the figure, the communication module 120 is shown as a single integrated module, but each network interface card may be arranged independently depending on the circuit configuration or application, contrary to the drawing.

[0104] The cellular communication interface card 121 can transmit and receive wireless signals to and from at least one of a base station 200, an external device, or a server using a mobile communication network, and provide cellular communication services in a first frequency band based on instructions from the processor 110. According to one embodiment, the cellular communication interface card 121 may include at least one NIC module that uses a frequency band of less 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, or a server in accordance with a cellular communication standard or protocol in a frequency band of less than 6 GHz supported by the NIC module.

[0105] The cellular communication interface card 122 can transmit and receive wireless signals to and from at least one of a base station 200, an external device, or a server using a mobile communication network, and can provide cellular communication services in a second frequency band based on instructions from the processor 110. In one embodiment, the cellular communication interface card 122 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 122 can independently perform cellular communication with at least one of the base station 200, an external device, or a server in accordance with a cellular communication standard or protocol in a frequency band of 6 GHz or higher supported by the NIC module.

[0106] The unlicensed band communication interface card 123 uses a third frequency band, which is an unlicensed band, to send and receive wireless signals with at least one of the base station 200, an external device, or a server, and provides communication services in the unlicensed band based on instructions from 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 2.4GHz, 5GHz, 6GHz, 7GHz, or 5GHz or higher than 52.6GHz. At least one NIC module of the unlicensed band communication interface card 123 can communicate wirelessly with at least one of the base station 200, an external device, or a server, independently or dependently, in accordance with the unlicensed band communication standard or protocol of the frequency band supported by the NIC module.

[0107] Next, the memory 130 stores the control program used by the terminal 100 and various data associated with it. Such a control program may include a predetermined program necessary for the terminal 100 to perform wireless communication with at least one of the base station 200, an external device, or a server.

[0108] Next, the user interface 140 includes various forms 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. Furthermore, the user interface 140 can output based on instructions from the processor 110 using various output means.

[0109] Next, the display unit 150 outputs various images to the display screen. The display unit 150 can output various display objects such as content executed by the processor 110 or user interfaces based on control instructions of the processor 110.

[0110] Furthermore, the base station 200 according to one embodiment of the present disclosure may include a processor 210, a communication module 220, and a memory 230.

[0111] First, the processor 210 can execute various instructions or programs and process data within the base station 200. Furthermore, the processor 210 can control the overall operation of the base station 200, including each unit, and control data transmission and reception between units. Here, the processor 210 may be configured to perform the operations described in the embodiments of this disclosure. For example, the processor 210 can signal slot configuration information and communicate according to the signaled slot configuration.

[0112] Next, the communication module 220 may be an integrated module that performs wireless communication using a wireless communication network and wireless LAN connection using a wireless LAN. For this purpose, the communication module 220 may be equipped with multiple network interface cards, such as cellular communication interface cards 221 and 222 and an unlicensed band communication interface card 223, either internally or externally. In the figure, the communication module 220 is shown as a single integrated module, but each network interface card may be arranged independently depending on the circuit configuration or application, contrary to the drawing.

[0113] The cellular communication interface card 221 can transmit and receive wireless signals to and from at least one of the terminal 100, external devices, and servers described above using a mobile communication network, and can provide cellular communication services in the first frequency band based on instructions from the processor 210. In one embodiment, the cellular communication interface card 221 may include at least one NIC module that uses a frequency band of less 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 devices, and servers in accordance with a cellular communication standard or protocol in a frequency band of less than 6 GHz supported by the NIC module.

[0114] The cellular communication interface card 222 can transmit and receive wireless signals to and from at least one of the terminal 100, an external device, and a server using a mobile communication network, and can provide cellular communication services in a second frequency band based on instructions from the processor 210. According to one embodiment, the cellular communication interface card 222 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 222 can independently perform cellular communication with at least one of the terminal 100, an external device, and a server in accordance with a cellular communication standard or protocol of a frequency band of 6 GHz or higher that the NIC module supports.

[0115] The unlicensed band communication interface card 223 uses a third frequency band, which is an unlicensed band, to send and receive wireless signals with at least one of the terminal 100, an external device, or a server, and provides communication services in the unlicensed band based on instructions from 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 2.4GHz, 5GHz, 6GHz, 7GHz, or 5GHz band above 52.6GHz. At least one NIC module of the unlicensed band communication interface card 223 can communicate wirelessly with at least one of the terminal 100, an external device, or a server, independently or dependently, in accordance with the unlicensed band communication standard or protocol of the frequency band supported by the NIC module.

[0116] The terminal 100 and base station 200 shown in Figure 11 are block diagrams according to one embodiment of the present invention, and the separately displayed blocks logically distinguish and show the elements of the device. Therefore, the above-described elements of the device may be mounted as a single chip or as multiple chips depending on the device design. 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. Furthermore, the user interface 140 and the display unit 150, etc., may be further provided in the base station 200 as needed.

[0117] Figure 12 shows a method for scheduling a physical uplink sharing channel in the time domain according to one embodiment of the present invention.

[0118] A terminal can transmit uplink data to a base station using PUSCH. A base station can schedule a terminal to transmit uplink data using PUSCH (PUSCH scheduling). i) As a Dynamic Grant (DG) method, a base station can perform PUSCH scheduling using DCI included in PDCCH. Or, ii) As a Configured Grant (CG) method, a terminal can transmit uplink data to a base station using PUSCH according to the resources and transmission method pre-configured by the base station for the terminal.

[0119] In this case, the DCI included in the PDCCH may include PUSCH scheduling information. For example, the DCI may include time-domain resource assignment (TDRA) and frequency-domain resource assignment (FDRA). The terminal can receive the DCI transmitted in the control resource set and search space and perform the operation indicated by the DCI (e.g., uplink data transmission using PUSCH). In this case, the format of the DCI for PUSCH scheduling may be DCI format 0_0, 0_1, or 0_2. The DCI of DCI format 0_0, 0_1, or 0_2 may be configured to include a TDRA field containing time-domain information for PUSCH. In this case, the time-domain information may include K2, which is the offset value between the slot from which the base station transmits the PDCCH and the slot from which the terminal transmits the PUSCH. The DCI may also include SLIV (Start and length indication value), which is a value that is a joint-coded value of the start symbol index (S) and the symbol length (L, number) of the PUSCH within the slot indicated by K2. When a terminal receives a DCI in slot n, the slot on which PUSCH is scheduled may be floor(n*2μPUSCH / n*2μPDCCH)+K2 slots. μPUSCH and μPDCCH can represent the subcarrier spacing (SCS) of the cell on which PUSCH is scheduled and the cell on which the terminal receives PDCCH, respectively. floor(x) is a function that returns the largest integer that is equal to or less than x. In this specification, slot n can represent the slot indexed with index n.

[0120] Referring to Figure 12(a), the subcarrier interval between the cell where the terminal receives PDCCH and the cell where PUSCH is scheduled may be the same. In this case, if the terminal receives PDCCH in slot n and K2 is instructed to be 4, the slot where PUSCH is scheduled may be slot n + K2, i.e., slot n + 4.

[0121] There are two possible mapping types for scheduling a PUSCH: PUSCH mapping type A and PUSCH mapping type B. The range of values ​​that can be the starting symbol index and SLIV of a PUSCH may vary depending on the PUSCH mapping type. PUSCH mapping type A allows resource allocations that include a DMRS symbol, and the DMRS symbol may be located as the third or fourth symbol in the slot, depending on the value indicated by the higher layer. That is, in the case of PUSCH mapping type A, the index (S) of the starting symbol of the PUSCH is 0, and the length (L) of the PUSCH can be any value from 4 to 14 (12 in extended CP), depending on the position of the DMRS symbol. In PUSCH mapping type B, the first symbol of the PUSCH may be the DMRS symbol. Therefore, S can be any value from 0 to 13 (11 in extended CP), and L can be any value from 1 to 14 (12 in extended CP). Additionally, no single PUSCH must cross the slot boundary, and the sum of S and L must be less than or equal to 14 (12 in extended CP).

[0122] Referring to Figure 12(b), the base station can schedule PUSCH mapping type A where the third symbol is a DMRS symbol, the starting symbol index (S) is 0, and the length (L) is 7; PUSCH mapping type A where the fourth symbol is a DMRS symbol, the starting symbol index (S) is 0, and the length (L) is 7; and PUSCH mapping type B where the first symbol is a DMRS symbol, the starting symbol index (S) is 5, and the length (L) is 5. In this case, the frequency domain information of PUSCH indicated in the FDRA fields of DCI format 0_0, 0_1, and 0_2 is divided into two types depending on the frequency resource allocation type.

[0123] Figure 13 shows a method for scheduling a physical uplink sharing channel in the frequency domain according to one embodiment of the present invention.

[0124] The frequency resource allocation types will be explained below with reference to Figure 13.

[0125] i) The first type, frequency resource allocation type 0 (type 0), may be a type in which a certain number of PRBs are bundled together to form an RBG based on the number of RBs included in the BWP configured (set) on the terminal, and a bitmap for each RB is used to indicate whether or not the RBG is used. That is, the terminal can determine whether or not the corresponding RBG is used by using the bitmap transmitted from the base station. The number of PRBs included in one RBG may be set (configured) from the upper layer, and the more RBs included in the BWP configured (configured) on the terminal, the more PRBs may be set (configured). Referring to Figure 13(a), the BWP size configured (configured) on the terminal is 72PRB, and one RBG may consist of 4PRBs. In this case, the terminal may determine that 4 PRBs in ascending order from PRB0 constitute one RBG, and each RBG may be indexed from 0. That is, an RBG consisting of PRBs from PRB0 to PRB3 may be indexed as RBG0, and an RBG consisting of PRBs from PRB4 to PRB7 may be indexed as RBG1. The same method may be used to index up to RBG17, in which case the base station transmits a total of 18 bits (0 or 1) for each RBG to the terminal, and the terminal can determine whether or not the PRBs constituting the corresponding RBG are used based on the received 18 bits. In this case, if the bit value is 0, the terminal can determine that no PUSCH is scheduled for any of the PRBs constituting the corresponding RBG. If the bit value is 1, the terminal can determine that PUSCH is scheduled for all PRBs in the corresponding RBG. In this case, the bit values ​​may be applied in reverse. ii) The second type, frequency resource allocation type 1, may be a type that indicates information on a sequence of PRBs allocated by the size of the terminal's initial BWP or active BWP. Information about consecutive PRBs may be a resource indication value (RIV) value that combines the start index (S) and length (L) of the consecutive PRBs.Referring to Figure 13(b), if the terminal has a BWP size of 50 PRBs and PUSCH is scheduled for PRB2 to PRB11 out of the 50 PRBs, the starting index of consecutive PRBs may be 2 and the length may be 10. In other words, the terminal can determine the starting index and length of consecutive PRBs on which 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 This can be the size of the BWP set on the terminal. For example, if the RIV value received by the terminal is 452, then 452 = 50 * (10 - 1) + 2 is calculated, and the terminal can determine that the starting index of the consecutive PRBs for which PUSCH is scheduled is 2 and the length is 10.

[0126] The DCI formats 0_1 and 0_2 used to schedule PUSCH may configure the terminal from the upper layer to use only one of the two frequency resource allocation types described above, or to dynamically use both types. If the terminal is configured to dynamically use both types, the terminal can determine which type it is using the MSB (most significant bit) bit of the FDRA field of the DCI.

[0127] There may be uplink shared channel transmission methods based on configured grants, such as those used for URLLC transmission. These configured grant-based uplink shared channel transmission methods may be described as grant-free transmissions. A configured grant-based uplink shared channel transmission method may involve the base station configuring resources available for uplink transmission to the terminal via higher layers (i.e., RRC signaling), and the terminal then transmitting uplink shared channels using these configured resources. Configured grant-based uplink shared channel transmission methods can be distinguished into two types depending on whether the DCI instructs activation or release. i) Type 1: A configured grant-based uplink shared channel transmission method may involve pre-configuring resources and transmission methods at higher layers. ii) Type 2: A configured grant-based uplink shared channel transmission method may involve configuring grant-based transmission at higher layers, with the DCI configuring the resources and methods for actual transmission.

[0128] Uplink transmission methods based on configured grants can support URLLC transmission. Therefore, to ensure high reliability, uplink transmissions may be repeated on multiple slots. In this case, the RV (redundancy version) sequence may be one of {0,0,0,0}, {0,2,3,1}, or {0,3,0,3}, and the RV corresponding to the mod(n-1, 4)+1 value may be used in the nth repeated transmission. That is, the RV corresponding to the remainder when n-1 is divided by 4 plus 1 may be used. Furthermore, a terminal configured to repeatedly transmit on the uplink channel can only start repeated transmission on the slot where the RV value is 0. However, if the RV sequence is {0,0,0,0} and the uplink channel is configured to be repeatedly transmitted on 8 slots, the terminal cannot start repeated transmission on the 8th slot. The terminal may terminate repeated transmissions when it reaches the number of repeated transmissions set in the upper layer, exceeds the cycle, or receives a UL grant with the same HARQ process ID. A UL grant can mean a DCI that schedules a PUSCH.

[0129] As described above, in order to improve the reliability of PUSCH transmission / reception 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.

[0130] Figure 14 shows repeated transmission of a physical uplink sharing channel according to one embodiment of the present invention.

[0131] There are two possible types of repeated PUSCH transmissions performed by a terminal. i) First, let's describe type A of repeated PUSCH transmission. When a terminal receives DCIs in DCI formats format0_1 and 0_2 from a base station that are included in a PDCCH that schedules a PUSCH, the terminal can repeatedly transmit PUSCHs on K consecutive slots. The K value may be set from a higher layer or may be a value set for the terminal by being included in the TDRA field of the DCI. For example, referring to Figure 14(a), the terminal can receive a PDCCH that schedules a PUSCH in slot n, and the K2 value may be set from the DCI included in the received PDCCH. In this case, if the K2 value is 2 and the K value is 4, the terminal can start repeated PUSCH transmissions in slot n+K2 and can repeatedly transmit PUSCHs up to slot n+K2+K-1. That is, the terminal starts repeated PUSCH transmissions in n+2 and repeatedly transmits PUSCHs up to n+5. In this case, the resources in the time domain and frequency domain for transmitting a PUSCH in each slot may be the same as those indicated in the DCI. That is, a PUSCH may be transmitted with the same symbol and PRB(s) within a slot. ii) Next, PUSCH repetition transmission type B will be described. PUSCH repetition transmission type B may be a type used by a terminal to repeatedly transmit low-latency PUSCHs to satisfy the requirements of URLLC, etc. The terminal may set the symbol (S) at which the repeated transmission of a PUSCH begins and the length (L) of the repeated PUSCH in the TDRA field of the DCI transmitted by the base station. In this case, the starting symbol (S) and length (L) may be for a nominal PUSCH that is determined on an ad-hoc basis, rather than for an actual PUSCH that the terminal actually transmits. There may not be any other symbols between nominal PUSCHs that are set to be repeatedly transmitted. That is, nominal PUSCHs may be consecutive in the time domain. The terminal can determine the actual PUSCH from the nominal PUSCH. A nominal PUSCH may be determined to be one or more actual PUSCHs. The base station may set a symbol for PUSCH repetition transmission type B that is unavailable on the terminal.Symbols unavailable for type B repetitive PUSCH transmissions may be described as invalid symbols. A terminal can exclude invalid symbols from the resources configured for a nominal PUSCH transmission. As described above, nominal PUSCHs are configured to be repeated over consecutive symbols, but if invalid symbols are excluded, the resources for nominal PUSCH transmissions become discontinuous. An actual PUSCH may be configured to be transmitted over consecutive symbols configured for a single nominal PUSCH transmission, excluding invalid symbols. In this case, if the consecutive symbols cross a slot boundary, the actual PUSCH transmitted may be split based on the slot boundary. Invalid symbols may include downlink symbols configured by the base station for the terminal. Referring to Figure 14(b), a terminal may have a PUSCH transmission of 5 symbol length scheduled starting from the 12th symbol in the first slot (slot n), with 4 type B repetitive transmissions configured. In this case, the resource scheduled with the first nominal PUSCH(nominal#1) can contain the symbols (n,11), (n,12), (n,13), (n+1,0), and (n+1,1). The resource scheduled with the second nominal PUSCH(nominal#2) can contain the symbols (n+1,2), (n+1,3), (n+1,4), (n+1,5), and (n+1,6). The resource scheduled with the third nominal PUSCH(nominal#3) can contain the symbols (n+1,7), (n+1,8), (n+1,9), (n+1,10), and (n+1,11). A resource scheduled with the fourth nominal PUSCH (nominal#4) can contain the symbols (n+1,12), (n+1,13), (n+2,0), (n+2,1), and (n+2,2). In this case, symbol (n,k) refers to symbol k in slot n. That is, k can be a value from 0 to 13 in normal CP, and a value from 0 to 11 in extended CP.Invalid symbols may be set to symbols 6 and 7 in slot n+1. In this case, the last symbol of the second nominal PUSCH (nominal#2) may be excluded to determine the actual PUSCH, and the first symbol of the third nominal PUSCH (nominal#3) may be excluded. The first nominal PUSCH (nominal#1) may be divided by the slot boundary into two actual PUSCHs (actual#1 and actual#2) that are actually transmitted. The second nominal PUSCH (nominal#2) and the third nominal PUSCH (nominal#3) may be combined into one actual PUSCH (actual#3 and actual#4) by excluding the invalid symbols. Finally, the fourth nominal PUSCH (nominal#4) may be divided by the slot boundary into two actual PUSCHs (actual#5 and actual#6) that are actually transmitted. The terminal ultimately transmits the actual PUSCH that it intends to send. Each actual PUSCH must contain at least one DMRS symbol. Therefore, if PUSCH repeat transmission type B is set, and the total length of an actual PUSCH is one symbol, such an actual PUSCH may be omitted and not transmitted. This is because an actual PUSCH consisting of one symbol cannot contain any information other than DMRS.

[0132] Frequency hopping may be configured for uplink channel transmission in order to obtain diversity gain in the frequency domain.

[0133] In PUSCH repetitive transmission type A, either intra-slot frequency hopping, where frequency hopping occurs within a slot, or inter-slot frequency hopping, where frequency hopping occurs for each slot, may be configured on the terminal. If intra-slot frequency hopping is configured on the terminal, the terminal can divide the PUSCH in the time domain into two parts in the slot from which it is transmitted: half is transmitted with a scheduled PRB, and the other half is transmitted with a PRB that is the scheduled PRB plus an offset value. In this case, the offset value may be set to two or four values ​​depending on the active BWP size at the upper layer, and one of these values ​​may be set (instructed) on the terminal by DCI. If inter-slot frequency hopping is configured on the terminal, the terminal can transmit the PUSCH with a scheduled PRB in slots with even slot indices, and transmit the PUSCH with a PRB that is the scheduled PRB plus an offset value in odd-numbered slots.

[0134] In PUSCH repetition transmission type B, either inter-repetition frequency hopping, where frequency hopping occurs at nominal PUSCH boundaries, or inter-slot frequency hopping, where frequency hopping occurs for each slot, may be configured on the terminal. When inter-repetition frequency hopping is configured on the terminal, the terminal can transmit actual PUSCHs corresponding to odd-numbered nominal PUSCHs on the scheduled PRB, and transmit actual PUSCHs corresponding to even-numbered nominal PUSCHs on the PRB obtained by adding an offset value to the scheduled PRB. In this case, the offset value may be set to two or four values ​​depending on the active BWP size at the upper layer, and any one of these values ​​may be set (instructed) on the terminal by DCI. When inter-slot frequency hopping is configured on the terminal, the terminal can transmit PUSCHs on the PRB scheduled for slots with even slot indices, and transmit PUSCHs on the PRB obtained by adding an offset value to the PRB scheduled for odd-numbered slots.

[0135] When a terminal performs repeated PUSCH transmissions, if a symbol scheduled for PUSCH transmission in a particular slot overlaps with a semi-statically configured DL symbol or a symbol set for receiving an SS / PBCH block, the terminal does not need to transmit the overlapping PUSCH on the slot containing the overlapping symbol. Furthermore, the overlapping PUSCH may be postponed and not transmitted on the next slot either.

[0136] When a terminal receives a DCI in DCI format 1_0, 1_1, or 1_2 that schedules a PUCCH, it must transmit a PUCCH to the base station. In this case, 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 a PDSCH is scheduled to the terminal with a DCI in DCI format 1_0, 1_1, or 1_2. The second type may be a HARQ-ACK for a DCI when the DCI in DCI format 1_0, 1_1, or 1_2 is a DCI that instructs the release of a semi-persistent scheduling (SPS) PDSCH. For sending a PUCCH containing a HARQ-ACK, the "PDSCH-to-HARQ_feedback timing indicator" field of the DCI can indicate K1, which is a value related to the slot to which the scheduled PUCCH will be sent. Here, K1 may be a non-negative integer value. A DCI in DCI format 1_0 can indicate one of the following values ​​for K1: {0, 1, 2, 3, 4, 5, 6, 7}. The K1 values ​​that can be indicated in DCIs in DCI formats 1_1 and 1_2 may be set (configured) from the upper layers.

[0137] This section describes how the slot on which a PUCCH containing a first type HARQ-ACK is transmitted is determined. There may be an uplink slot where the last symbol on which a HARQ-ACK and its corresponding PDSCH are transmitted overlaps. In this case, if the index of the overlapping uplink slot is m, the terminal can transmit a PUCCH containing a HARQ-ACK on slot m+K1. The index of the uplink slot may be a value determined based on the subcarrier interval of the BWP on which the PUCCH is transmitted. When downlink slot aggregation is configured on the terminal, the last symbol on which a PDSCH is transmitted may mean the last scheduled symbol in the last slot on which a PDSCH is transmitted.

[0138] Figure 15 shows a scheduling method for a physical uplink control channel according to one embodiment of the present invention.

[0139] Referring to Figure 15, the subcarrier interval of the DL BWP where PDCCH is received, the subcarrier interval of the DL BWP where PDSCH is scheduled, and the subcarrier interval of the UL BWP where PUCCH is transmitted may be the same. The terminal can receive the PDCCH that schedules PDSCH and PUCCH from the base station in slot n. At this time, the DCI included in the PDCCH received in slot n can be set (instructed) to have a K0 value of 2 and a K1 value of 3. For example, if the last symbol transmitted for PDSCH is n+K0 (i.e., n+2), the terminal can transmit a HARQ-ACK for PDSCH on slot n+2+K1 (i.e., n+5). At this time, the HARQ-ACK for PDSCH may be included in PUCCH.

[0140] Figure 16 shows repeated transmission of a physical uplink control channel according to one embodiment of the present invention.

[0141] In the NR system, to ensure wide coverage, the terminal can repeatedly transmit long PUCCH on 2, 4, or 8 slots. At this time, the format of long PUCCH may be PUCCH format 1, 3, or 4. When the terminal repeatedly transmits PUCCH, the same UCI may be repeatedly transmitted every slot. Referring to FIG. 16, when the reception of PDSCH ends at slot n and the K1 value is 2, the terminal can transmit PUCCH on slot n + K1 (i.e., n + 2). When the base station sets the number of repeated transmissions of PUCCH to 4 (N repeat PUCCH = 4), the terminal can repeatedly transmit PUCCH on the slots from slot n + 2 to slot n + 5. At this time, the symbol configuration of the repeatedly transmitted PUCCH may be the same. That is, the repeatedly transmitted PUCCH may start from the same symbol of each slot and be composed of the same number of symbols.

[0142] In PUCCH transmission, frequency hopping may be applied to obtain diversity gain in the frequency domain. When intra-slot frequency hopping is applied, the terminal divides the time domain of the slot on which to transmit a PUCCH into two halves, allowing half of the PUCCH to be transmitted on the first PRB and the other half on the second PRB. The first and second PRBs may be configured in the higher layer where the PUCCH resources are set. When inter-slot frequency hopping is applied, the terminal can transmit a PUCCH on the first PRB of slots with even slot indices and on the second PRB of slots with odd slot indices. Also, when performing repeated PUCCH transmission, if the symbols of a particular slot scheduled for PUCCH transmission overlap with semi-statically configured DL symbols or symbols set for receiving SS / PBCH blocks, the terminal does not need to transmit a PUCCH on the slot containing the overlapping symbols. The terminal can postpone transmitting untransmitted PUCCHs to the next slot. In this case, if the symbol for sending a PUCCH in the deferred slot does not overlap with the semi-statically configured DL symbol or the symbol set for receiving an SS / PBCH block, the terminal can send a PUCCH.

[0143] In the present invention, we propose a method for solving the coverage problem related to PUSCH transmission performed by a terminal when a random access process occurs between a terminal and a base station.

[0144] As described above with reference to Figure 3, during the random access process, the terminal transmits Msg3 PUSCH via the uplink grant (UL grant) included in the random access response (RAR, Msg2). In this case, the UL grant is information for scheduling Msg3 PUSCH and includes frequency hopping information, frequency hopping flag, time-domain resource allocation (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 via the uplink grant included in Msg2 is the initial transmission PUSCH. On the other hand, if the base station cannot receive Msg3 PUSCH from the terminal, the base station instructs the terminal to retransmit the Msg3 PUSCH. The retransmission of Msg3 PUSCH is instructed (scheduled) by PDCCH, and in this case, the retransmission is instructed via DCI in DCI format 0_0, which is scrambled with Temporary C-RNTI (TC-RNTI) included in PDCCH. The terminal obtains TC-RNTI via a previously received random access response (Msg2). If the terminal successfully detects the DCI instructing retransmission, the terminal retransmits Msg3 PUSCH based on the information contained in the DCI. In this case, the information contained in the DCI includes frequency hopping flags, 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. Msg3 PUSCH instructed via DCI in DCI format 0_0 is a retransmission PUSCH.

[0145] In other words, the Msg3 PUSCH described in this invention is either an initial transmission PUSCH or a retransmission PUSCH. Specifically, a PUSCH indicated via the uplink grant of the random access response (Msg2) is for initial transmission, and a PUSCH indicated via DCI in DCI format 0_0 scrambled with TC-RNTI is for retransmission.

[0146] Traditionally, the initial transmission PUSCH and the retransmission PUSCH were transmitted in only one slot. This single slot was 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 Msg3 PUSCH was impossible. Therefore, if a terminal could not receive a PDCCH scheduling Msg4 from the base station within a set time after transmitting Msg3 PUSCH, the terminal would determine that the random access process had failed and had to restart the random access process from the beginning. For example, in poor channel conditions, even if a terminal transmits Msg3 PUSCH, the base station may fail to receive it. Therefore, the base station cannot transmit a PDCCH scheduling Msg4 to the terminal, and the random access process must be restarted. In short, Msg3 has low PUSCH coverage. Therefore, there is a risk of delays in the overall random access process. Therefore, the present invention will now describe a method for solving the coverage problem of Msg3 PUSCH through repeated transmission of Msg3 PUSCH.

[0147] The base station sets whether or not Msg3 PUSCH can be repeatedly transmitted during the random access process. For example, the base station sets whether or not Msg3 PUSCH can be repeatedly transmitted to the terminal via System Information Block 1 (SIB1), which is transmitted from the base station during the initial access process. In other words, the terminal checks whether or not Msg3 PUSCH can be repeatedly transmitted via SIB1. Whether or not Msg3 PUSCH can be repeatedly transmitted may be set not only via SIB1 but also via other SIBs. That is, whether or not Msg3 PUSCH can be repeatedly transmitted may be set via SIBx (x=1, 2, 3, ...). Furthermore, whether or not Msg3 PUSCH can be repeatedly transmitted may be indicated via other channels. For example, the base station sets whether or not Msg3 PUSCH can be repeatedly transmitted via PBCH. More specifically, whether or not Msg3 PUSCH can be repeatedly transmitted may be set via some bits of PBCH, or it may be inferred via the DMRS sequence or CRC of PBCH.

[0148] Whether Msg3 PUSCH can be repeatedly transmitted is either explicitly indicated or inferred from other information contained in SIB1. For example, if SIB1 includes parameters for the repeated transmission of Msg3 PUSCH, the terminal will determine that Msg3 PUSCH can be repeatedly transmitted without any separate setting (instruction) regarding whether or not Msg3 PUSCH can be repeatedly transmitted. Conversely, if SIB1 does not include parameters for the repeated transmission of Msg3 PUSCH, the terminal will determine that Msg3 PUSCH cannot be repeatedly transmitted without any separate setting (instruction) regarding whether or not Msg3 PUSCH can be repeatedly transmitted. In this case, the parameters for the repeated transmission of Msg3 PUSCH indicate the PRACH resource on which Msg3 PUSCH will be repeatedly transmitted and the number of times Msg3 PUSCH will be repeatedly transmitted. For example, if a terminal has a PRACH resource set via SIB1, the terminal will repeatedly transmit Msg3 PUSCH via the set PRACH resource. Furthermore, if the terminal has set the number of times Msg3 PUSCH can be repeatedly transmitted via SIB1, the terminal will transmit Msg3 PUSCH the set number of times. In this case, the base station sets a single value or multiple values ​​for the number of times Msg3 PUSCH can be repeatedly transmitted to the terminal. For example, the base station sets one value from 1, 2, 4, and 8 to the terminal, or a set containing multiple values ​​(e.g., {1, 2, 4, 8}). In other words, the base station sets a single value to the terminal as the number of times Msg3 PUSCH can be repeatedly transmitted, or sets multiple values ​​that are possible for the number of repetitions. If the base station sets multiple values, the base station instructs the terminal to use one of the multiple values ​​via additional signaling (setting), etc. If the Msg3 PUSCH transmitted by the terminal is repeatedly transmitted, Msg3 PUSCH is repeatedly transmitted in slot units. For example, if the number of times Msg3 PUSCH can be repeatedly transmitted is 4, Msg3 PUSCH will be repeatedly transmitted on 4 slots. In other words, it means that the Msg3 PUSCH message transmitted on a single slot is repeated four times.

[0149] If it is configured that repeated transmission of Msg3 PUSCH is possible via SIB1, the method for determining whether or not the terminal actually transmits Msg3 PUSCH repeatedly will be described. Furthermore, the meaning of "interpreted by the terminal" as described herein is the same as the meaning of "configured by the base station" on the terminal. Furthermore, the meaning of "configured" as described herein is the same as the meaning of "instructed".

[0150] Method for determining whether repeated transmission of Msg3 PUSCH on a terminal is permitted. If a base station configures a terminal to enable repeated transmission of Msg3 PUSCH within a cell, the terminal will always recognize that it will repeatedly transmit Msg3 PUSCH, even without any additional signaling (configuration) from the base station instructing it to do so.

[0151] i) The terminal determines whether to repeatedly transmit Msg3 PUSCH based on explicit information received from the base station. The explicit information that the terminal uses to determine whether to repeatedly transmit Msg3 PUSCH is as follows:

[0152] ia) Information from higher layers: The terminal interprets the information from higher layers and decides whether repeated transmission of Msg3 PUSCH is possible. For example, the base station sets whether repeated transmission of Msg3 PUSCH is possible within the cell via SIB1 during the initial cell access process, and in addition, if it is set that repeated transmission of Msg3 PUSCH is possible, it sets the terminal to always repeatedly transmit Msg3 PUSCH.

[0153] ib) Information within the downlink channel scheduling Msg3 PUSCH: The terminal interprets the information within the downlink channel scheduling Msg3 PUSCH and determines whether repeated transmission of Msg3 PUSCH is permitted. In this case, the downlink channel includes the uplink grant of the random access response, or the DCI of DCI format 1_0 that schedules the random access response, or the DCI of DCI format 0_0 that schedules Msg3 PUSCH. Specifically, the terminal interprets the field information within the uplink grant of the random access response that schedules the initial transmission of Msg3 PUSCH and determines whether repeated transmission of Msg3 PUSCH is permitted. The terminal interprets the field information within the DCI of DCI format 0_0 scrambled with TC-RNTI that schedules the retransmission of Msg3 PUSCH and determines whether repeated transmission of Msg3 PUSCH is permitted. The terminal interprets the field information within the DCI of DCI format 1_0 that schedules the random access response and determines whether transmission of Msg3 PUSCH is permitted. In this process, one bit within the information contained in each downlink channel (i.e., the uplink grant, DCI format 1_0, and DCI format 0_0) is used to indicate whether or not Msg3 PUSCH can be repeatedly transmitted. The terminal then decides whether or not to repeatedly transmit Msg3 PUSCH based on the indication of whether or not the PUSCH can be repeatedly transmitted indicated by the aforementioned one bit.

[0154] ii) The terminal determines whether to repeatedly transmit Msg3 PUSCH based on implicit information transmitted by the base station. The implicit information that the terminal uses to determine whether to repeatedly transmit Msg3 PUSCH is as follows:

[0155] The terminal reinterprets the information within the downlink channel that schedules the Msg3 PUSCH and determines whether the Msg3 PUSCH can be repeatedly transmitted. For example, ii-a) The terminal reinterprets the field information within the uplink grant that schedules the initial transmission of the Msg3 PUSCH and determines whether the Msg3 PUSCH can be repeatedly transmitted. ii-b) The terminal reinterprets the field information within the DCI in DCI format 0_0, scrambled with TC-RNTI, that schedules the retransmission of the Msg3 PUSCH and determines whether the Msg3 PUSCH can be repeatedly transmitted. In this case, the field in ii-a) and ii-b) is one of the TDRA, FDRA, MCS, or TPC fields. The method for interpreting the field is as follows.

[0156] The terminal determines whether to reinterpret the TDRA 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 reinterprets the field information in the uplink grant of the random access response to determine whether to repeatedly transmit Msg3 PUSCH. Since the base station assigns a large number of symbols to terminals with insufficient coverage, if the number of assigned symbols is greater than or equal to a predetermined number, the terminal repeatedly transmits Msg3 PUSCH to resolve the coverage issue. In other words, if the number of assigned symbols is less than the predetermined number, the terminal does not repeatedly transmit Msg3 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 reinterprets the field information in the uplink grant of the random access response to determine whether to repeatedly transmit Msg3 PUSCH. This is because assigning a small number of symbols to a terminal by the base station could cause insufficient coverage. In other words, if the base station assigns more symbols than a certain number, the terminal will not repeatedly transmit Msg3 PUSCH. In this case, the certain number is set from a higher layer. The higher layer refers to SIB1 or other SIBs.

[0157] Based on the number of PRBs scheduled by the FDRA field, the terminal reinterprets 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 certain number, the terminal reinterprets 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 terminals with insufficient coverage, if the number of allocated PRBs is greater than or equal to a predetermined number, the terminal repeatedly transmits the Msg3 PUSCH to resolve the coverage problem. In other words, if the number of allocated PRBs is less than the predetermined number, the terminal will not repeatedly transmit the Msg3 PUSCH. As another example, if the number of PRBs indicated by the FDRA field is less than or equal to a certain number, the terminal reinterprets 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 too few PRBs to the terminal, a coverage problem may occur. In other words, if the base station allocates more PRBs to a terminal than a specified number, the terminal will not repeatedly transmit Msg3 PUSCH. In this case, the specified number is set from a higher layer. The higher layer refers to SIB1 or other SIBs.

[0158] The terminal reinterprets the MCS field based on the modulation scheme or coding rate indicated by the MCS field to determine whether to transmit Msg3 PUSCH. For example, if the MCS field indicates a low modulation scheme (e.g., QPSK) or a low coding rate, the terminal reinterprets the field information in the uplink grant of the random access response to determine whether to repeatedly transmit Msg3 PUSCH. The base station sets a low modulation scheme or low coding rate for terminals with insufficient coverage, so if the modulation scheme or coding rate is low, the terminal will repeatedly transmit Msg3 PUSCH.

[0159] Tables 4 and 5 show the modulation scheme and coding rate to be set on the terminal. In Tables 4 and 5, the modulation order refers to the modulation scheme. If the modulation order is q, it means pi / 2-BPSK (q=1) or QPSK (q=2); if it is 2, it means QPSK; if it is 4, it means 16 QAM; if it is 6, it means 64 QAM; and if it is 8, it means 256 QAM.

[0160] [Table 4] [Table 5]

[0161] Table 4 applies if the transform precoding for PUSCH transmission on the terminal is set to disabled, and Table 5 applies if it is set to enabled. When the terminal is scheduled to perform an initial transmission of Msg3 PUSCH (i.e., when the transmission of Msg3 PUSCH is set in the uplink grant of the random access response), the base station sets the first 16 indices (0-15) in Table 4 or Table 5. For example, referring to Table 4, the base station sets QPSK, 16QAM, and 64QAM as the modulation scheme on the terminal, and referring to Table 5, the base station sets pi / 2-BPSK, QPSK, 16QAM, and 64QAM as the modulation scheme on the terminal. The lowest modulation schemes are pi / 2-BPSK or QPSK. In other words, once the terminal is set to pi / 2-BPSK or QPSK, the terminal will repeatedly transmit Msg3 PUSCH.

[0162] Based on the TPC command indicated by the TPC field, the terminal reinterprets the field to determine whether to repeatedly transmit Msg3 PUSCH. For example, if the TPC command indicated by the TPC field is greater than or equal to a specific value, the terminal reinterprets the field information in the uplink grant of the random access response to determine whether to repeatedly transmit Msg3 PUSCH. The base station instructs a high value (greater than or equal to a specific value) TPC command to transmit with high power to terminals with insufficient coverage. Therefore, if the terminal receives a TPC command greater than or equal to a specific value, the terminal will repeatedly transmit Msg3 PUSCH. In other words, if the base station sets the TPC command to be less than a specific value for the terminal, the terminal will not repeatedly transmit Msg3 PUSCH.

[0163] Based on the TB size, the terminal reinterprets the fields to determine whether to repeatedly transmit the Msg3 PUSCH. The terminal determines the TB size of the Msg3 PUSCH based on the FDRA field, TDRA field, MCS field, etc., and then determines whether to repeatedly transmit the Msg3 PUSCH based on the TB size. For example, if the TB size is below a certain value, the terminal reinterprets the field information in the uplink grant of the random access response to determine whether to repeatedly transmit the Msg3 PUSCH. The base station allocates a small size (below a certain value) of TB to terminals with insufficient coverage, so if a terminal is allocated a TB below a certain value, it will repeatedly transmit the Msg3 PUSCH. In other words, if a terminal is allocated a TB larger than a certain value, it will not repeatedly transmit the Msg3 PUSCH.

[0164] The following describes how the terminal determines the number of times Msg3 PUSCH is transmitted.

[0165] Method for determining the number of repeated transmissions for Msg3 PUSCH The terminal determines the number of times Msg3 PUSCH will be transmitted based on the number of repetitions set by the base station. The terminal then repeatedly transmits Msg3 PUSCH according to the number of repetitions set by the base station. Before instructing the number of repetitions, the base station sets several candidate repetition counts on the terminal. These candidate repetition counts are predetermined values, set in broadcasting information, or set at a higher level. For example, the candidate repetition counts are structured as {N1, N2, N3, N4, ...}. In this case, the candidate repetition counts (N1, N2, N3, N4, ...) are natural numbers greater than or equal to 1 and are powers of 2. For example, multiple candidate repetition counts could be {1, 2, 4, 8}. The terminal then repeatedly transmits Msg3 PUSCH only one of the values ​​1, 2, 4, or 8 instructed by the base station.

[0166] i) The terminal is configured by the upper layer to determine the number of times Msg3 PUSCH will be transmitted. For example, if the terminal is configured by the upper layer to transmit an integer value of n as the number of times Msg3 PUSCH will be transmitted, the terminal will transmit Msg3 PUSCH n times.

[0167] ii) The base station sets the number of times Msg3 PUSCH will be transmitted by using the fields of the DCI in DCI format 0_0, which schedules Msg3 PUSCH, or the DCI in DCI format 1_0, which schedules random access responses (Msg2), to the terminal. For example, the terminal interprets a certain number of bits in the DCI in DCI format 1_0, which is scrambled with RA-RNTI, which schedules random access responses, as bits indicating the number of times Msg3 PUSCH will be transmitted, and then transmits Msg3 PUSCH repeatedly. As another example, the terminal interprets a certain number of bits in the DCI in DCI format 0_0, which is scrambled with TC-RNTI, which schedules the retransmission of Msg3 PUSCH, as bits indicating the number of times Msg3 PUSCH will be transmitted, and then transmits Msg3 PUSCH repeatedly.

[0168] In this case, the number of repeated transmissions, instructed either i) from the upper layer or ii) in DCI format 0_0 or 1_0, is one value from among several candidate values ​​for the number of repeated transmissions. Next, the terminal repeatedly transmits Msg3 PUSCH only the number of times specified.

[0169] The fields containing a certain number of bits within the DCI format 0_0 scrambled with TC-RNTI as described in ii) above are the NDI (New data indicator), HPN (HARQ process number), CSI request, FDRA, and TPC fields. Since the NDI, HPN, and CSI request fields are not used for Msg3 PUSCH transmission, the terminal interprets the values ​​of the NDI, HPN, and CSI request fields as field values ​​for repeated transmission of Msg3 PUSCH.

[0170] For terminals with insufficient coverage, the base station will either schedule the PUSCH with a small number of PRBs in the frequency domain or schedule it with the highest maximum transmit power. Therefore, the terminal will either interpret a certain number of bits in the FDRA field as field values ​​for repeated transmission of Msg3 PUSCH, or interpret some of the indices indicating low dB values ​​in the TPC field as field values ​​for repeated transmission of Msg3 PUSCH.

[0171] The following describes how the terminal interprets a certain number of bits within the DCI format 0_0, which has been scrambled with TC-RNTI, for repeated transmission of Msg3 PUSCH. The candidate number of repeated transmissions for Msg3 PUSCH set on the terminal are {N1, N2, N3, N4}.

[0172] The terminal interprets the bit value of one of the DCI fields in the DCI format 0_0, scrambled with TC-RNTI, as the number of repetitions for Msg3 PUSCH. In other words, the terminal interprets the X bit of one of the NDI, HPN, CSI request, FDRA, and TPC fields as the field value for the repetition of Msg3 PUSCH. For example, the terminal interprets the X (e.g., 2) bit of the HPN field as the field value for the repetition of Msg3 PUSCH. In this case, the base station uses the 2 bits to indicate one of the four repetition counts (N1, N2, N3, N4). For example, {00}=N1, {01}=N2, {10}=N3, {11}=N4.

[0173] The terminal interprets the number of repetitions for Msg3 PUSCH as a combination of bit values ​​from two different fields in the DCI format 0_0, which is scrambled with TC-RNTI. In other words, the terminal interprets the X bit from one of the NDI, HPN, CSI request, FDRA, and TPC fields, and the Y bit from one of the NDI, HPN, CSI request, FDRA, and TPC fields that does not contain the X bit, as the field value for the repetitions of Msg3 PUSCH. For example, the terminal interprets the combination of the X bit (e.g., 1) from the NDI field and the Y bit (e.g., 1) from the HPN field, i.e., 2 bits, as the field value for the repetitions of Msg3 PUSCH. In this case, the base station uses the 2 bits to indicate one of the four candidate repetition counts. For example, {0,0}=N1, {0,1}=N2, {1,0}=N3, {1,1}=N4 in {NDI,HPN}. Or, {0,0}=N1, {0,1}=N2, {1,0}=N3, {1,1}=N4 in {HPN,NDI}. As another example, the terminal interprets the combination of the X (e.g., 1) bit in the NDI field and the Y (e.g., 1) bit in the CSI request field, i.e., 2 bits, as the field value for repeated transmission of Msg3 PUSCH. In this case, if the candidate number of repeated transmissions for Msg3 PUSCH set on the terminal is {N1, N2, N3, N4}, the base station uses the 2 bits to indicate one of the four candidate number of repeated transmissions. For example, {0,0}=N1, {0,1}=N2, {1,0}=N3, {1,1}=N4 are set in {NDI, CSI request}. Or, {0,0}=N1, {0,1}=N2, {1,0}=N3, {1,1}=N4 are set in {CSI request, NDI}.

[0174] The terminal interprets the bit values ​​of two different fields in the DCI format 0_0, scrambled with TC-RNTI, as field values ​​for repeated transmission of Msg3 PUSCH. More specifically, the terminal interprets the X bit of any one field of the DCI and the Y bit of the other field that does not contain the X bit as field values ​​for repeated transmission of Msg3 PUSCH. For example, the X bit indicates whether the terminal interprets the Y bit as a field value for repeated transmission of Msg3 PUSCH, and the Y bit indicates the number of times Msg3 PUSCH will be transmitted. For example, one bit in the NDI field indicates whether or not to interpret the Y bit in the FDRA field as a field value for repeated transmission of Msg3 PUSCH. If the value of one bit in the NDI field is "0", the Y bit in the FDRA field is not interpreted as a field value for repeated transmission of Msg3 PUSCH. If the value of one bit in the NDI field is "1", the Y bit in the FDRA field is interpreted as a field value for repeated transmission of Msg3 PUSCH. In this case, the Y bit indicates one of the candidate repeat transmission counts for Msg3 PUSCH that are pre-configured in the terminal. For example, if the value of one bit in the NDI field is "1", the Y bit (e.g., 2) in the FDRA field indicates one of the four candidate repeat transmission counts. Specifically, {00}=N1, {01}=N2, {10}=N3, {11}=N4 are set in {FDRA}. As another example, one bit in the CSI request field indicates whether the terminal interprets the Y bit in the HPN field as the field value for repeated transmission of Msg3 PUSCH. If the value of the one bit in the CSI request field is "0", the Y bit in the HPN field is not interpreted as the field value for repeated transmission of Msg3 PUSCH. If the value of the one bit in the CSI request field is "1", the Y bit in the HPN field is interpreted as the field value for repeated transmission of Msg3 PUSCH.If the value of bit 1 in the CSI request field is "1", then bit Y (for example, 2) in the HPN field indicates one of the four repeat transmission counts. Specifically, {00}=N1, {01}=N2, {10}=N3, {11}=N4 in {HPN}.

[0175] iii) The terminal is instructed of the number of times Msg3 PUSCH will be transmitted via a specific field in the uplink grant of the random access response that schedules the initial transmission of Msg3 PUSCH. The terminal transmits Msg3 PUSCH repeatedly according to the instructed number of transmissions. The terminal interprets the bit value of the specific field in the uplink grant as the field value for the repeated transmission of Msg3 PUSCH. In this case, the specific bit in the uplink grant indicates one of several numbers of repeated transmissions of Msg3 PUSCH. The specific field in the uplink grant is the CSI request, FDRA, TPC, or MCS field. In this case, since the CSI request field is not used for Msg3 PUSCH transmission, the terminal interprets the value of the CSI request field as the field value for the repeated transmission of Msg3 PUSCH. For example, since the base station schedules terminals with insufficient coverage with a small number of PRBs in the frequency domain, the terminal interprets the bit value of the FDRA field as the field value for the repeated transmission of Msg3 PUSCH. As another example, a base station schedules PUSCH with the highest transmit power to terminals with insufficient coverage, so the terminal interprets some of the indices indicating lower dB values ​​in the TPC field as field values ​​for repeated transmission of Msg3 PUSCH. In this case, the TPC field has a size of 3 bits, and the TPC values ​​indicated by each code point are as shown in Table 6. As yet another example, terminals with insufficient coverage are scheduled to transmit PUSCH with the lowest modulation scheme (e.g., QPSK) and / or a lower coding rate. Therefore, the terminal interprets some of the lower indices among the first 16 MCS indices (0-15) in Tables 4 and 5 contained in the MCS field as field values ​​for repeated transmission of Msg3 PUSCH.

[0176] [Table 6]

[0177] The following further explains how to interpret a specific number of bits within the uplink grant of a random access response. The candidate number of repeated transmissions for Msg3 PUSCH set on the terminal are {N1, N2, N3, N4}. The bit value of any one of the fields in the uplink grant is Msg3

[0178] The system is configured to specify the number of times PUSCH will be transmitted. In other words, the terminal interprets the value of the X bit in a specific field among the CSI request, FDRA, TPC, and MCS fields as the repeated transmission field value for Msg3 PUSCH.

[0179] For example, the base station sets the X (e.g., 2) bit of the FDRA field as the field value for repeated transmission of Msg3 PUSCH, and uses the X (e.g., 2) bit to indicate one of four (N1, N2, N3, N4) repeat transmission counts. The terminal determines 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 is determined as X = ceil(log2(M)) if there are M repeat transmission count candidates set in the higher layer. In this specification, ceil(x) is a function that returns the smallest integer that is equal to or greater than x. The X bit is the X bits from the MSB of the FDRA field, excluding the bits that indicate frequency hopping. More specifically, if the number of RBs in the initial uplink BWP (initial UL BWP) is less than 50, then X bits are the second bit to X bits in the FDRA field; if the number of RBs is greater than or equal to 50, then X bits are the third bit to X bits in the FDRA field.

[0180] For example, the base station sets the X (e.g., 2) bit of the TPC field as the bit for the field used for repeated transmission of Msg3 PUSCH, and uses the 2 bits of the TPC field to indicate one of the four possible number of repeated transmissions. The terminal determines that if the bit value of the TPC field is "00", it will be N1; if it is "01", it will be N2; if it is "10", it will be N3; and if it is "11", it will be N4. The X bit of the TPC field is determined as X = ceil(log2(M)) if there are M candidates for the number of repeated transmissions set in the higher layer. The X bit is either the first (MSB) X bit or the last (LSB) X bit of the 3-bit TPC field.

[0181] For example, the base station sets the X (e.g., 2) bit of the MCS field as the bit for the field for repeated transmission of Msg3 PUSCH, and uses the 2 bits of the MCS field to indicate one of the four possible number of repeated transmissions. The terminal determines 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 is determined as X = ceil(log2(M)) if there are M candidates for the number of repeated transmissions set in the higher layer. The X bit is either the first (MSB) X bit or the last (LSB) X bit of the 4-bit MCS field.

[0182] The terminal interprets the number of repetitions 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 repetitions of Msg3 PUSCH is Z, the terminal interprets Z bits combined from the bits of two different fields as the number of repetitions of Msg3 PUSCH. The terminal interprets X bits of the first field and Y bits of the second field among the CSI request, FDRA, TPC, and MCS fields as bits for the repeated transmission of Msg3 PUSCH. The first field and the second field are different fields, and X + Y = Z. Also, X < Z, Y < Z, and Z is at least 2 bits or more. On the other hand, if the terminal interprets X = Z bits of the first field as the number of repetitions of Msg3 PUSCH, the number of repetitions of Msg3 PUSCH is indicated using the X bits of the first field.

[0183] If there are M candidates for the number of repetitions of Msg3 PUSCH (for example, 4 {N1, N2, N3, N4}), Z bits are required to indicate the number of repetitions to the terminal. At this time, Z = ceil(log2(M)) bits. If M is 4, Z is 2. For example, X (for example, 1) bit of the first field (for example, CSI request field) and Y (for example, 1) bit of the second field (for example, FDRA field, MCS field) are interpreted as bits for the repeated transmission of Msg3 PUSCH, and the base station uses 2 bits to indicate any one of the four numbers of repetitions. 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 repetitions is set to N1, if {0, 1}, it is set to N2, if {1, 0}, it is set to N3, and if {1, 1}, it is set to N4.

[0184] In addition to the above-described embodiments, for the repeated transmission of Msg3 PUSCH in the DCI of DCI format 0_0 scrambled with TC-RNTI and the uplink grant of the random access response, the field is at least one or more fields among the TDRA, FDRA, MCS, and TPC fields. At this time, the terminal reinterprets the bit values of one or more fields to perform the repeated transmission of Msg3 PUSCH. Hereinafter, a specific method for interpreting the bit values of the fields will be further described. The candidate number of repeated transmissions of Msg3 PUSCH set for the terminal is {N1, N2, N3, N4}.

[0185] The terminal performs the repeated transmission of Msg3 PUSCH based on the number of symbols scheduled (assigned) by the TDRA field. For example, if the number of symbols assigned to the transmission of Msg3 PUSCH by the terminal is 1 to (M1 - 1) symbols, the number of repeated transmissions is set to N1; if it is M1 to (M2 - 1) symbols, the number of repeated transmissions is set to N2; if it is M2 to (M3 - 1) symbols, the number of repeated transmissions is set to N3; if it is M3 to (M4 - 1) symbols, the number of repeated transmissions is set to N4. At this time, M1 < M2 < M3 < M4 and N1 > N2 > N3 > N4. This is because if the base station assigns a small number of symbols to the terminal, the coverage shortage phenomenon may deepen. That is, if the number of symbols assigned is small, the terminal repeats the transmission of Msg3 PUSCH more times. As another example, N1 < N2 < N3 < N4. This is because the base station assigns a large number of symbols to the terminal with insufficient coverage. That is, if the base station assigns a large number of symbols, the terminal repeats the transmission of Msg3 PUSCH more times. At this time, the number of symbols to be assigned is set from the upper layer, and specifically, it is set by SIB1 or other SIBs.

[0186] The terminal performs repeated transmission of Msg3 PUSCH based on the number of PRBs scheduled by the FDRA field. For example, if the number of PRBs allocated for PUSCH transmission is 1 to (M1 - 1) PRBs, the terminal sets the number of repeated transmissions to N1; if it is M1 to (M2 - 1) PRBs, the number of repeated transmissions is set to N2; if it is M2 to (M3 - 1) PRBs, the number of repeated transmissions is set to N3; if it is M3 to (M4 - 1) PRBs, the number of repeated transmissions is set to N4. Here, M1 < M2 < M3 < M4 and N1 > N2 > N3 > N4. This is because if the base station allocates a small number of PRBs to the terminal, there is a risk of the coverage shortage phenomenon intensifying. That is, if the number of allocated PRBs is small, the terminal repeats the transmission of Msg3 PUSCH more times. As another example, N1 < N2 < N3 < N4. This is because the base station allocates a large number of PRBs to terminals with insufficient coverage. That is, if the base station allocates a large number of PRBs, the terminal repeats the transmission of Msg3 PUSCH more times. At this time, the number of allocated PRBs is set by the upper layer. Specifically, it is set by SIB1 or other SIBs.

[0187] The terminal performs repeated transmission of Msg3 PUSCH based on the modulation method or coding rate indicated by the MCS field. For example, if the index on the MCS table (table) indicated by the MCS field in the terminal is 0 to (M1 - 1), the number of repeated transmissions is set to N1; if it is M1 to (M2 - 1), the number of repeated transmissions is set to N2; if it is M2 to (M3 - 1), the number of repeated transmissions is set to N3; if it is M3 to (M4 - 1), the number of repeated transmissions is set to N4. Here, M1 < M2 < M3 < M4 and N1 > N2 > N3 > N4. This is because the base station sets a low modulation method or coding rate for terminals with insufficient coverage. That is, the lower the modulation level or coding rate is set, the more times the terminal repeats the transmission of Msg3 PUSCH.

[0188] The terminal repeatedly transmits Msg3 PUSCH based on the TPC command indicated by the TPC field. For example, if the TPC command index indicated by the TPC field is 0 to (M1-1), the terminal determines the number of repeated transmissions to be N1; if it is M1 to (M2-1), it determines the number of repeated transmissions to be N2; if it is M2 to (M3-1), it determines the number of repeated transmissions to be N3; and if it is M3 to (M4-1), it determines the number of repeated transmissions to be N4. <M2<M3<M4で、N1> N2 > N3 > N4. This is because base stations set high TPC command values ​​to transmit with high power to terminals with insufficient coverage. In other words, the higher the TPC command value set, the more frequently the terminal will transmit Msg3 PUSCH.

[0189] The terminal repeatedly transmits Msg3 PUSCH based on the TB size. For example, the terminal determines the TB size on 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 terminal determines the number of repeated transmissions to be N1; if it is M1 to (M2-1), it determines the number of repeated transmissions to be N2; if it is M2 to (M3-1), it determines the number of repeated transmissions to be N3; and if it is M3 to (M4-1), it determines the number of repeated transmissions to be N4. <M2<M3<M4で、N1> N2 > N3 > N4. This is because the base station sets a smaller TB size for terminals with insufficient coverage. In other words, the smaller the TB size set, the more frequently the terminal will transmit Msg3 PUSCH.

[0190] iv) The terminal is configured by the base station with a TDRA table containing the number of times Msg3 PUSCH has been repeatedly transmitted. Each entry in the TDRA table contains time-domain resource information and information about the number of times Msg3 PUSCH has been repeatedly transmitted. Each entry may contain the same number of transmissions or different numbers of transmissions. The terminal determines the number of times Msg3 PUSCH has been repeatedly transmitted by referring to the TDRA table. For example, if the terminal is configured to repeatedly transmit Msg3 PUSCH, it will repeatedly transmit Msg3 PUSCH by referring to the TDRA table. On the other hand, if the terminal is configured not to repeatedly transmit Msg3 PUSCH, it will transmit Msg3 PUSCH by referring to the conventional TDRA table. In this case, the conventional TDRA table refers to a table that does not contain the number of times Msg3 PUSCH has been repeatedly transmitted.

[0191] The one or more transmission repetition counts described herein are values ​​used in common or independently for the initial transmission and retransmission of Msg3 PUSCH. If the base station instructs the terminal to retransmit Msg3 PUSCH, the terminal determines the transmission repetition count for the retransmission of Msg3 PUSCH based on the transmission repetition count instructed for the initial transmission of Msg3 PUSCH.

[0192] The terminal determines the number of retransmissions for Msg3 PUSCH via bits in a specific field of the DCI transmitted by the base station, or via the TDRA table. In this case, the DCI is DCI format 0_0, scrambled with TC-RNTI.

[0193] a) The bit value indicates that the number of repeated transmissions for the retransmission of Msg3 PUSCH is the same as the number of repeated transmissions for the initial transmission of Msg3 PUSCH. For example, if some bits of the bit value are 0 or all bits value are 0, the terminal will determine that the number of repeated transmissions for the retransmission of Msg3 PUSCH is the same as the number of repeated transmissions for the initial transmission of Msg3 PUSCH.

[0194] b) The number of repeated transmissions for the retransmission of Msg3 PUSCH is determined based on the number of repeated transmissions for the initial transmission of Msg3 PUSCH.

[0195] bi) One of the DCI bits indicates that the number of retransmissions for Msg3 PUSCH is the same as the number of retransmissions for the initial transmission.

[0196] b-ii) One of the DCI bits indicates that the number of retransmissions for Msg3 PUSCH retransmission is greater than the number of retransmissions for Msg3 PUSCH initial transmission. Specifically, one of the DCI bits indicates that the number of retransmissions for Msg3 PUSCH retransmission is twice as great as the number of retransmissions for Msg3 PUSCH initial transmission. If the number of retransmissions for Msg3 PUSCH initial transmission has already reached the maximum number of retransmissions (or if the determined number of retransmissions for Msg3 PUSCH retransmission exceeds the maximum number of retransmissions), the terminal performs Msg3 PUSCH retransmission using the maximum number of retransmissions.

[0197] b-iii) One of the DCI bits indicates that the number of retransmissions for the retransmission of Msg3 PUSCH is less than the number of retransmissions for the initial transmission of Msg3 PUSCH. Specifically, one of the DCI bits indicates that the number of retransmissions for the retransmission of Msg3 PUSCH is half the number of retransmissions for the initial transmission of Msg3 PUSCH. If the initial number of retransmissions of Msg3 PUSCH has already reached the minimum number of retransmissions (e.g., the number of retransmissions is 1) (or if the determined number of retransmissions for the Msg3 PUSCH retransmission is less than the minimum number of retransmissions (e.g., the number of retransmissions is 1)), the terminal performs the Msg3 PUSCH retransmission using the minimum number of retransmissions.

[0198] The bits in the specific fields of the DCI described above are replaced by some entries in the TDRA table. For example, the number of retransmissions for the retransmission of Msg3 PUSCH indicated by some entries in the TDRA table is the same as, greater than (e.g., twice as great) or less than (e.g., half as great) the number of retransmissions for the initial transmission of Msg3 PUSCH.

[0199] How to interrupt repeated transmissions of Msg3 PUSCH If a terminal is configured by the base station to repeatedly transmit Msg3 PUSCH K times, the terminal will repeatedly transmit Msg3 PUSCH K times. In this case, since the repeatedly transmitted Msg3 PUSCH is the same, if the base station successfully receives some of the K Msg3 PUSCHs, repeated transmission of Msg3 PUSCH becomes unnecessary. Therefore, the following describes how to interrupt the repeated transmission of Msg3 PUSCH.

[0200] i) The terminal decides whether to repeatedly transmit Msg3 PUSCH based on whether it can receive the PDCCH that schedules Msg4. After the initial transmission of Msg3 PUSCH, the terminal detects the PDCCH that schedules Msg4 transmitted from the base station. When the terminal receives the PDCCH that schedules Msg4, the terminal recognizes that the base station successfully received Msg3 PUSCH. Therefore, once the terminal schedules the PDCCH that schedules Msg4, it interrupts the repeated transmission of Msg3 PUSCH. The PDCCH that schedules Msg4 contains DCI in DCI format 1_0, scrambled with TC-RNTI.

[0201] ii) The terminal determines whether to repeatedly transmit Msg3 PUSCH based on whether it can receive the PDCCH that schedules the retransmission of Msg3 PUSCH. After the initial transmission of Msg3 PUSCH, the terminal detects the PDCCH that schedules the retransmission of Msg3 PUSCH transmitted from the base station. At this time, if the terminal receives the PDCCH that schedules Msg3, the terminal receives the scheduling information for the new Msg3 PUSCH. Therefore, the terminal interrupts the repeated transmission of Msg3 PUSCH that it was previously transmitting. The PDCCH that schedules Msg3 PUSCH contains DCI in DCI format 0_0, which is scrambled with TC-RNTI.

[0202] iii) The terminal determines whether to repeatedly transmit Msg3 PUSCH based on whether it receives the uplink grant of the random access response (Msg2) that schedules the initial transmission of Msg3 PUSCH. After the transmission of the first Msg3 PUSCH, the terminal receives the PDCCH that schedules the uplink grant of Msg2 and the uplink grant of Msg2. If the terminal receives the uplink grant of Msg2 or the PDCCH that schedules the uplink grant of Msg2, the terminal is set with new scheduling information for Msg3 PUSCH. Therefore, the terminal interrupts the repeated transmission of Msg3 PUSCH that is already being transmitted. The PDCCH that schedules the uplink grant of Msg2 contains DCI in DCI format 1_0, scrambled with RA-RNTI.

[0203] iv) The terminal repeatedly transmits Msg3 PUSCH within a specific time window, and stops repeatedly transmitting Msg3 PUSCH when the specific time window ends. In this case, repeated transmission of Msg3 PUSCH is not transmitted in certain situations (for example, situations in which repeated transmission of Msg3 PUSCH is interrupted as described in i) to iii) above), and is deferred to the next slot. Therefore, there is a risk that repeated transmission of Msg3 PUSCH may be delayed for a certain period of time. To prevent this, the terminal repeatedly transmits Msg3 PUSCH only during a specific time (slot) from the first transmission of Msg3 PUSCH. In other words, the terminal repeatedly transmits Msg3 PUSCH within a specific time (slot), but does not repeatedly transmit Msg3 PUSCH after the specific time (slot) ends.

[0204] As described above, the terminal reinterprets the CSI request field, FDRA field, TPC, and MCS field to determine the number of times Msg3 PUSCH will be transmitted. Below, we will explain how the terminal determines whether or not to reinterpret the CSI request field, FDRA field, and TPC field to determine the number of times Msg3 PUSCH will be transmitted.

[0205] Method for determining whether field reinterpretation is permitted for the number of repeated transmissions of Msg3 PUSCH. i) If a terminal is configured by the base station to have a separate PRACH resource (e.g., PRACH preamble, RACH opportunity) set up for the repeated transmission of Msg3 PUSCH, and the terminal transmits a PRACH to the base station on the said separate PRACH resource, the terminal reinterprets the CSI request field, FDRA field, and TPC field in the manner described above. Conversely, a terminal that transmits a PRACH that is not on the said separate PRACH resource will always reinterpret the CSI request field, FDRA field, or TPC field for its original purpose. In this case, the separate PRACH resource is included in SIB1 and configured by the base station on the terminal. In other words, the terminal repeatedly transmits Msg3 PUSCH on a resource determined based on at least one of the PRACH preamble and RACH opportunity. For example, the base station checks on what resource the PRACH transmitted to the terminal is transmitted. If the PRACH transmitted by the terminal was transmitted over the aforementioned separate PRACH resource, the base station uses at least one or two of the CSI request field, FDRA field, and TPC field to indicate the number of times Msg3 PUSCH will be transmitted. When the base station indicates the number of repetitions, it sets the number of repetitions to 1. In other words, it sets Msg3 PUSCH not to be transmitted repeatedly. In this case, one of the pre-configured candidate values ​​for the number of repetitions (e.g., N1, N2, N3, N4) is set to "1". N1 may also be a value that is predetermined to be 1 (not set separately), and the base station may set only the values ​​of N2, N3, and N4.

[0206] On the other hand, the base station instructs the number of times Msg3 PUSCH should be transmitted via a specific field (e.g., the CSI request field). As mentioned above, even if a terminal transmits PRACH on a resource separately configured by the base station, the base station instructs via a specific field that Msg3 PUSCH should not be transmitted repeatedly. In this case, if the base station instructs via a specific field (e.g., the CSI request field) that Msg3 PUSCH should be transmitted repeatedly, the number of transmissions will be instructed using at least one or two of the FDRA field and the TPC field. In this case, the base station does not need to instruct 1 as the number of transmissions for Msg3 PUSCH, because it can instruct via the specific field that Msg3 PUSCH should not be transmitted repeatedly. Therefore, the values ​​of the candidate transmission counts (N1, N2, N3, N4) do not have to include 1. In other words, the candidate transmission counts are set to values ​​greater than 1.

[0207] ii) The terminal decides whether to reinterpret the CSI request field, FDRA field, and TPC field for the purpose of repeated transmission of Msg3 PUSCH based on the value of a specific field. In this case, the specific field is one of the fields in the uplink grant of the random access response. For example, the specific field may be the CSI request field, in which case the decision to reinterpret is based on the value of one bit of the CSI request field. If the value of the CSI request field is 0, the terminal interprets the FDRA field and TPC field for their original purpose (not for the purpose of determining whether to repeatedly transmit Msg3 PUSCH). If the value of the CSI request field is 1, the terminal reinterprets the FDRA field and TPC field. In this case, since the CSI request field is used to determine whether to reinterpret, the CSI request field is excluded from the fields that are reinterpreted for repeated transmission of Msg3 PUSCH as described above.

[0208] Method for determining transmission power command values The terminal should determine the TPC command value of Msg3 PUSCH. If the Msg3 PUSCH is repeatedly transmitted, the terminal determines the highest 8 dB increase in Table 6 as the transmission power command value. On the other hand, if the terminal repeatedly transmits Msg3 PUSCH, the base station sets a specific value as the TPC value for the terminal.

[0209] The terminal determines the transmission power command value based on the remaining bit(s) excluding the X bit for the repeated transmission of Msg3 PUSCH. Since the number of the remaining bit(s) is 3 - X, the remaining bit(s) is 1 bit or 2 bits.

[0210] Hereinafter, a specific method for determining the TPC value based on the remaining bit(s) will be described.

[0211] i) If the remaining bit is 1 bit, the terminal inserts "11" into the 2 bits which are the MSB. Thus, the terminal determines the TPC value based on "11a" (where a is the value of the remaining 1 bit) and Table 6. If the value of the remaining 1 bit (a) is 0, it means "110", and since "110" is 6, referring to Table 6, it means a 6 dB increase. If the value of the remaining 1 bit (a) is 1, it means "111", and since "111" is 7, referring to Table 6, it means an 8 dB increase. That is, referring to Table 6, the terminal is only instructed with the two highest TPC command values (6, 7).

[0212] ii) If the remaining bit is 1 bit, the TPC value is determined by the value of the 1 bit. Specifically, the TPC value is determined according to Table 7.

[0213]

Table 7

[0214] Referring to Table 7, the terminal uses the TPC_0 value if the remaining bit is a 1-bit value (a) of "0", and uses the TPC_1 value if the remaining bit is a 1-bit value of "1". TPC_0 and TPC_1 are predetermined values ​​or values ​​set separately by the base station. The TPC_0 and TPC_1 values ​​are two values ​​from -6, -4, -2, 0, 2, 4, 6, and 8. The TPC_0 value is one of the negative values ​​(or non-positive values) from -6, -4, -2, 0, 2, 4, 6, and 8, and the TPC_1 value is one of the positive values. In addition, to expand PUSCH coverage, TPC_0 and TPC_1 are determined to be two positive (or non-negative) values ​​from -6, -4, -2, 0, 2, 4, 6, and 8. The difference between the TPC_0 and TPC_1 values ​​is 4dB. More specifically, TPC_0 is 4dB and TPC_1 is 8dB, or TPC_0 is 2dB and TPC_1 is 6dB, or TPC_0 is 0dB and TPC_1 is 84dB. On the other hand, the difference between the TPC_0 and TPC_1 values ​​is 8dB. More specifically, TPC_0 is 8dB and TPC_1 is 8dB.

[0215] If there are 2 bits remaining, the terminal inserts a "1" into the MSB1 bit, similar to method i). Thus, the terminal determines the TPC value based on Table 6 as "1ab" (where ab is the value of the remaining 2 bits). That is, if the value of the remaining 2 bits (ab) is 00, it means "100", and since "100" is 4, it means a 2dB increase. Similarly, if the value of the remaining 2 bits is 01, it means "101", and since "101" is 5, it means a 4dB increase. If the value of the remaining 2 bits is 10, it means "110", and since "110" is 6, it means a 6dB increase. If the value of the remaining 2 bits is 11, it means "111", and since "111" is 7, it means an 8dB increase. The terminal is instructed to use only the four highest TPC command values ​​(4, 5, 6, 7) from Table 6.

[0216] If there are 2 bits remaining, the four TPC values ​​are determined based on the remaining 2 bits, similar to method ii). For details, see Table 8 for how the TPC values ​​are determined.

[0217] [Table 8]

[0218] The terminal uses the TPC_0 value if the remaining 2 bits (ab) are "00", the TPC_1 value if they are "01", the TPC_2 value if they are "10", and the TPC_3 value if they are "11". TPC_0, TPC_1, TPC_2, and TPC_3 are predetermined values ​​or values ​​set separately by the base station. The TPC_0, TPC_1, TPC_2, and TPC_3 values ​​are four values ​​from -6, -4, -2, 0, 2, 4, 6, and 8. The TPC_0 value is one of the negative values ​​(or non-positive values) from -6, -4, -2, 0, 2, 4, 6, and 8, while the TPC_1, TPC_2, and TPC_3 values ​​are positive values. Also, the TPC_0 and TPC_1 values ​​are negative values ​​(or non-positive values) from -6, -4, -2, 0, 2, 4, 6, and 8, while the TPC_2 and TPC_3 values ​​are positive values. Furthermore, to expand PUSCH's coverage, the TPC_0, TPC_1, TPC_2 through TPC_3 values ​​are four positive values ​​(or non-negative values) from -6, -4, -2, 0, 2, 4, 6, and 8. Also, the difference between the TPC_0, TPC_1, TPC_2, and TPC_3 values ​​is 4dB. Specifically, TPC_0 is -6dB, TPC_1 is -2dB, TPC_2 is 2dB, and TPC_3 is 6dB. Alternatively, TPC_0 is -4dB, TPC_1 is 0dB, TPC_2 is 4dB, and TPC_3 is 8dB.

[0219] The above describes the signaling methods used by base stations for the repeated transmission of Msg3 PUSCH. It was possible to set information regarding the repeated transmission of Msg3 PUSCH by using some bits of a specific field in the uplink grant or DCI of the random access response. The method of using some bits has the problem of overhead, as some bits should be added. It was also possible to set information regarding the repeated transmission of Msg3 PUSCH by reinterpreting a specific field in the uplink grant or DCI, or by reinterpreting bits in a specific field. The reinterpretation method has the problem of restricting the flexible scheduling of the base station. Furthermore, there is a risk that the base station may not be able to know whether or not the terminal will support the repeated transmission of Msg3 PUSCH. In this case, even if the base station sets information regarding the repeated transmission of Msg3 PUSCH, the terminal may not only be unable to perform the repeated transmission of Msg3 PUSCH, but may also misinterpret the uplink grant or DCI. To address this, the following describes how a terminal can inform the base station whether repeated transmission of Msg3 PUSCH is possible or the number of times it should be repeated when transmitting Msg3 PUSCH.

[0220] Information signaling method for repeated transmission using Msg3 PUSCH Figure 17 shows the repeated transmission of Msg3 PUSCH according to one embodiment of the present invention.

[0221] Referring to Figure 17, the terminal repeatedly transmits Msg3 PUSCH on four slots. Each Msg3 PUSCH transmitted in each slot transmits the same TB. Each slot repeatedly transmits the same TB with the same or different redundancy versions (RV). Each Msg3 PUSCH transmitted in each slot contains at least one DMRS symbol. A DMRS symbol means a symbol to which DMRS is mapped. Each Msg3 PUSCH transmitted in each slot contains multiple DMRS symbols. Of the multiple DMRS symbols, the DMRS symbol transmitted earliest in time is described as the first DMRS symbol, and subsequent DMRS symbols are described as additional DMRS symbols. For convenience of explanation, in this specification, the first DMRS symbol is referred to as the DMRS symbol, but it is clear that this also means additional DMRS symbols.

[0222] The base station configures the terminal with information regarding the transmission of Msg3 PUSCH (for example, via the uplink grant), and therefore has prior knowledge of the resources (slot, symbol, PRB, etc.) on which the first Msg3 PUSCH (Msg3 PUSCH rep#1) is transmitted. The base station also has prior knowledge of the location of the DMRS symbol included in Msg3 PUSCH rep#1. Based on information regarding repeated transmissions, the base station receives Msg3 PUSCH rep#1 transmitted by the terminal. 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 only receives Msg3 PUSCH rep#1. However, if the channel environment is poor, the base station cannot decode the TB transmitted by Msg3 PUSCH rep#1 even if it only receives Msg3 PUSCH rep#1. In this case, the base station receives the second Msg3 PUSCH (Msg3 PUSCH rep#2) in the slot following the transmission of Msg3 PUSCH rep#1. More specifically, the base station determines whether or not to receive Msg3 PUSCH rep#2 on the same symbol position and / or PRB as Msg3 PUSCH rep#1 in the slot following the transmission of Msg3 PUSCH rep#1. The base station cannot confirm whether or not the terminal repeatedly transmits Msg3 PUSCH. Therefore, in order to determine whether or not to receive Msg3 PUSCH rep#2, the base station measures the energy of the time-frequency resource where Msg3 PUSCH rep#2 is expected to be transmitted and measures the DMRS correlation diagram at the time-frequency resource where the DMRS of Msg3 PUSCH rep#2 is expected to be transmitted. Based on these measurement results, the base station determines (confirms) whether or not the terminal transmitted Msg3 PUSCH rep#2. Based on the measurement results, if the base station determines that Msg3 PUSCH rep#2 has been transmitted, the base station will combine Msg3 PUSCH rep#1 and Msg3 PUSCH rep#2 to obtain a lower code rate, increasing the likelihood of decoding the TB transmitted by Msg3 PUSCH.Since a code rate can be obtained, the probability of decoding the TB transmitted by Msg3 PUSCH increases. The process by which the base station decides whether or not to repeatedly transmit Msg3 PUSCH is repeated in slots where Msg3 PUSCH may be transmitted. However, in the case of terminals that repeatedly transmit Msg3 PUSCH, there is a problem that they may be located at the edge of the cell and have insufficient coverage, and therefore the performance may degrade compared to the aforementioned measurement results. In addition, there is a problem that the complexity increases because the base station must check whether or not to repeatedly transmit Msg3 PUSCH for each slot.

[0223] Figure 18 shows a repetitive transmission of Msg3 PUSCH using three DMRS according to one embodiment of the present invention.

[0224] Referring to Figure 18, there are three methods for transmitting Msg3 PUSCH messages from a terminal: (a) The terminal transmits the Msg3 PUSCH message without repetition. In other words, the terminal transmits the Msg3 PUSCH message in only one slot and does not repeat it in the next slot. (b) The terminal transmits the Msg3 PUSCH message twice. This is applied when the uplink channel environment is poor but more repeated transmissions of the Msg3 PUSCH message are not necessary. (c) The terminal transmits the Msg3 PUSCH message four times. This is applied when the uplink channel environment is even worse than in method (b).

[0225] Also, referring to Figure 18, the terminal uses DMRS to instruct the base station on how to transmit Msg3 PUSCH (whether or not it should be transmitted repeatedly). Specifically, if the terminal transmits Msg3 PUSCH using method (a), DMRS A is used to instruct on how to transmit Msg3 PUSCH. If the terminal transmits Msg3 PUSCH using method (b), DMRS B for Msg3 PUSCH rep#1 and Msg3 PUSCH rep#2 in each of the two slots is used to instruct on how to transmit Msg3 PUSCH. If the terminal transmits Msg3 PUSCH using method (c), DMRS C for Msg3 PUSCH rep#1, Msg3 PUSCH rep#2, Msg3 PUSCH rep#3 and Msg3 PUSCH rep#4 in each of the four slots is used to instruct on how to transmit Msg3 PUSCH. In other words, if the base station receives DMRS A, it recognizes that Msg3 PUSCH will be transmitted once; if it receives DMRS B, it recognizes that Msg3 PUSCH will be transmitted twice; and if it receives DMRS C, it recognizes that Msg3 PUSCH will be transmitted four times.

[0226] DMRS A, DMRS B, and DMRS C each have different base sequences. Because DMRS A, DMRS B, and DMRS C each have different base sequences, the base station measures the correlation diagram between each base sequence to determine which base sequence is applied.

[0227] The basic sequences of DMRS A, DMRS B, and DMRS C are the same, but they are sequence-initialized with different sequence initial values. If DMRS A is sequence-initialized with the first value, DMRS B and DMRS C are sequence-initialized with the second value and the third value respectively. The base station assumes sequence initialization with the first value, the second value, and the third value to measure the correlation diagram, and determines which sequence initialization value was used based on the measurement result of the correlation diagram. For example, the DMRS of Msg3 PUSCH with transmit precoding activated is as shown in Equation 1.

[0228] [Number]

[0229] N in Equation 1 slot symb is the number of symbols per slot, n μ s、f is the slot index in a frame with subcarrier spacing configuration μ, l is the OFDM symbol index in the slot, N ID nSCID is the DMRS sequence initialization value n SCID (0 to 1) means the scrambling identity. Referring to Equation 1, DMRS A, DMRS B, and DMRS C are at least divided into different c_init values. [[ID=​​​​​​The base station determines whether the DMRS on the first slot in which Msg3 PUSCH is transmitted is DMRS A, DMRS B, or DMRS C, and confirms whether Msg3 PUSCH is repeatedly transmitted or the number of times of repeated transmission. Then, the base station receives Msg3 PUSCH according to the determination result of the DMRS.

[0232] However, since a terminal with low coverage repeatedly transmits Msg3 PUSCH, there is a possibility that the probability of the base station correctly determining the DMRS of Msg3 PUSCH will be low. Therefore, it is likely that the accuracy of the base station's determination of the transmission method of Msg3 PUSCH on the first slot via one of a number of DMRSs (DMRS A, DMRS B, DMRS C) is low. Thus, hereinafter, a method for a terminal to indicate the transmission method of Msg3 PUSCH using two DMRSs (DMRS A and DMRS B) will be described.

[0233] FIGS. 19 to 21 are diagrams showing a method for transmitting Msg3 PUSCH using two DMRSs according to an embodiment of the present invention.

[0234] Referring to FIG. 19, (a) if Msg3 PUSCH is not repeatedly transmitted, DMRS A is used to indicate the transmission method of Msg3 PUSCH. (b) If Msg3 PUSCH is repeatedly transmitted twice, or (c) if it is repeatedly transmitted four times, DMRS B is used to indicate the transmission method of Msg3 PUSCH. That is, the terminal uses DMRS A or DMRS B to notify the base station whether Msg3 PUSCH can be repeatedly transmitted. The base station determines whether Msg3 PUSCH has been repeatedly transmitted by using the DMRS on the first slot in which Msg3 PUSCH is transmitted. For example, if the base station determines that the received DMRS is DMRS A, it determines that Msg3 PUSCH is not repeatedly transmitted. Conversely, if the base station determines that the received DMRS is DMRS B, it determines that Msg3 PUSCH is repeatedly transmitted.

[0235] DMRS A is either the same as or different from the DMRS of a terminal that does not have the capability to repeatedly transmit Msg3 PUSCH. If the DMRS is the same, even if the base station determines that the DMRS on the slot is DMRS A, it cannot determine whether the terminal that transmitted Msg3 PUSCH is capable of repeatedly transmitting Msg3 PUSCH. Therefore, when instructing the retransmission of Msg3 PUSCH, the base station must either not be able to instruct repeated transmission of the retransmission, or even if instructed, it must additionally determine whether the retransmission was actually repeated. On the other hand, if the DMRS is different (i.e., the base station receives DMRS B), the base station determines that the terminal that transmitted Msg3 PUSCH is capable of repeatedly transmitting Msg3 PUSCH. Therefore, when the base station instructs the retransmission of Msg3 PUSCH, it instructs repeated transmission of the retransmission.

[0236] Referring to Figure 20, if the terminal does not transmit Msg3 PUSCH in the slot after the first slot, it transmits DMRS A on the first slot. If Msg3 PUSCH is repeatedly transmitted in the slot after the first slot, it transmits DMRS B on the first slot. In other words, if Msg3 PUSCH is not repeatedly transmitted, or if the Msg3 PUSCH transmitted on the first slot is the last of the repeatedly transmitted Msg3 PUSCHs, DMRS A is used. For example, referring to Figure 20a, the terminal does not repeatedly transmit Msg3 PUSCH, so DMRS A is used. Referring to Figure 20b, since Msg3 PUSCH is repeatedly transmitted on the first and second slots, DMRS B is transmitted on the first slot and DMRS A is transmitted on the second slot. Referring to Figure 20c, since Msg3 PUSCH is transmitted repeatedly on the first, second, third, and fourth slots, DMRS B is transmitted on the first, second, and third slots, and DMRS A is transmitted on the fourth slot. In other words, the base station determines whether the DMRS containing Msg3 PUSCH in each slot is DMRS A or DMRS B. If the DMRS determined in the first slot is DMRS A, the base station determines that there will be no Msg3 PUSCH transmitted in the slots after the first slot. Conversely, if the DMRS determined in the first slot is DMRS B, the base station determines that Msg3 PUSCH will be transmitted repeatedly in the slots after the first slot. On the other hand, although the base station determines the DMRS for each slot, there are cases where it is not necessary to determine the DMRS for a particular slot. For example, if the number of repeat transmissions for Msg3 PUSCH set on the terminal is {R_1, R_2, ..., R_r}, then DMRS A will only be transmitted in slots R_1, R_2, and R_r. Therefore, the base station can determine whether or not there are additional Msg3 PUSCH transmissions by only checking the DMRS for slots R_1, R_2, ..., R_r. More specifically, if the number of repeat transmissions for Msg3 PUSCH set on the terminal is {1, 2, 4}, then DMRS A will only be transmitted on the first, second, and fourth slots.Therefore, if Msg3 PUSCH is transmitted four times repeatedly as shown in Figure 20c, the base station only needs to determine the DMRS for the first, second, and fourth slots. In other words, it does not need to determine the DMRS for the third slot in Figure 20c. However, in the method explained via Figure 20, if the base station fails to receive the Msg3 PUSCH transmitting DMRS A, the base station cannot determine which slot the transmission of Msg3 PUSCH will end in. For example, in a Msg3 PUSCH transmitted twice repeatedly, if the base station fails to receive the Msg3 PUSCH containing the DMRS transmitted on the second slot, the base station cannot determine which slot the transmission of Msg3 PUSCH will end in.

[0237] Referring to Section 21, the terminal transmits DMRS A in a specific number of consecutive slots of Msg3 PUSCH. The specific number is a predetermined value determined by the number of times Msg3 PUSCH is repeatedly transmitted. The specific number is half the number of times Msg3 PUSCH is repeatedly transmitted. In other words, if Msg3 PUSCH is transmitted twice, the specific number is 1, and if it is transmitted four times, the specific number is 2. To put it another way, if Msg3 PUSCH is transmitted R times, the specific number is f(R / 2). In this case, f(x) is a function that returns one of the following values ​​of x: truncated, rounded to the nearest integer, or rounded up. The specific number of consecutive slots is calculated from the slot where the repeated transmission of Msg3 PUSCH ends. Referring to Figure 21c, Msg3 PUSCH is transmitted four times, but Msg3 PUSCH containing DMRS A is transmitted on two consecutive slots from the last slot (i.e., the third and fourth slots). In the method shown in Figure 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 will terminate the transmission of Msg3 PUSCH in the fourth slot.

[0238] In the method using two DMRSs, as explained in Figures 19 to 21, different DMRSs are transmitted to each of the different slots. However, if the base station must perform joint channel correction, the same DMRS must be transmitted. Therefore, the method using two DMRSs applies to all situations except when joint channel estimation is performed.

[0239] Information signaling method for repeated transmission of Msg3 PUSCH using UCI bits Figures 22 to 26 show a method for determining the number of modulation symbols for multiplexing uplink control information contained in Msg3 PUSCH according to one embodiment of the present invention.

[0240] The number of modulation symbols for Uplink Control Information (UCI) transmission per layer mapped to Msg3 PUSCH is calculated as shown in Equation 2. Equation 2 is also used to calculate the number of modulation symbols when multiplexing and transmitting HARQ-ACK to PUSCH.

[0241]

number

[0242] In equation 2, O CUI This represents the number of bits indicating whether repeated transmission of Msg3 PUSCH can be performed and the number of repeated transmissions. UCI is O CUI This refers to the number of CRC bits used when channel coding. PUSCH offset This is an offset value for determining the number of resources to map UCI to Msg3 PUSCH, and is set by SIB. UL-SCH This refers to the number of code blocks (CBs) contained in Msg3 PUSCH. r This means the r-th CB size included in Msg3 PUSCH. UCI SC(l) is the l-th symbol of Msg3 PUSCH and represents the number of REs used in UCI transmission. PUSCH symb、all This refers to the total number of symbols used to transmit Msg3 PUSCH, including DMRS. The scaling value can be set via SIB. l0 refers to the index of the first non-DMRS PUSCH symbol after the DMRS symbol. For example, if DMRS is transmitted at the lth symbol, M UCI SC (l) is 0, otherwise M UCI SC (l) is M PUSCH sc -M PT-RS sc (l) M PUSCH sc M is the number of subcarriers scheduled to PUSCH in the frequency domain. PT-RS sc (l) represents the number of subcarriers of the l-th PUSCH symbol, including PTRS. The terminal is Q', calculated from equation 2. UCI Multiplexing UCI to PUSCH based on the number of modulation symbols (REs). Q' UCI This modulation symbol is Q' of Msg3 PUSCH UCI It is mapped to each RE. In this case, the mapping method is the same as the method used when HARQ-ACK is multiplexed to PUSCH. That is, Q' is mapped to the symbol immediately following the DMRS symbol in Msg3 PUSCH. UCI Each RE is selected.

[0243] Terminals that do not support repeated transmission of Msg3 PUSCH cannot transmit Msg3 PUSCH via UCI multiplexing. Therefore, when a base station receives Msg3 PUSCH, it needs to determine whether or not the UCI has been multiplexed. For example, if the size of the UCI bits is less than or equal to 2 bits, the terminal will determine whether or not Q' of the REs to which Msg3 PUSCH is transmitted. UCI Puncturing each RE, Q' UCIEach RE transmits the UCI. Therefore, the base station does not need to distinguish whether the UCI is multiplexed or not. In other words, the Q' on which the UCI is transmitted. UCI The mapping of Msg3 PUSCH does not change with each RE. On the other hand, if, for example, the size of the UCI bit is greater than 2 bits, then Msg3 PUSCH will be the Q' to which the UCI is mapped. UCI The data is transmitted via rate-matching around each RE. The base station must decode Msg3 PUSCH twice because the matching of Msg3 PUSCH changes depending on whether the UCI is multiplexed or not, due to different rate-matching conditions. Therefore, to reduce the number of decoding cycles at the base station, the size of the UCI bits must be limited to 2 bits or less.

[0244] If the UCI bit size is 1 bit, then i) the UCI bit indicates that the number of repetitions of Msg3 PUSCH is 1 or R. R is a value set in the SIB. 1 is not set separately, and if the value of the UCI bit size is "0", the number of repetitions is always determined to be 1. ii) The UCI bit indicates that the number of repetitions of Msg3 PUSCH is R_1 or R_2. R_1 and R_2 values ​​are values ​​set in the SIB. In this case, R_1 and R_2 are not 1.

[0245] If the UCI bit size is 2 bits, the UCI bit indicates i) that the number of repetitions of Msg3 PUSCH is 1, R_1, R_2, or R_3. R_1, R_2, and R_3 are values ​​set in the SIB. 1 is not set separately, and if the UCI bit is "00", the number of repetitions is always determined to be 1. ii) The UCI bit indicates that the number of repetitions of Msg3 PUSCH is R_1, R_2, R_3, or R_4. R_1, R_2, R_3, and R_4 are values ​​set in the SIB.

[0246] If the terminal needs to specify a wider variety of transmission counts, such as {1, 2, 4, 8, 16, 32}, then the size of the UCI bits should be greater than 2 bits. Therefore, a method for transmitting UCIs exceeding 2 bits will be described.

[0247] Referring to Figure 23, the terminal generates sub-UCIs by grouping UCI bits into groups of up to two bits each. The terminal transmits these sub-UCIs in the first and second slots, respectively. The terminal multiplexes and transmits the first sub-UCI in the Msg3 PUSCH on the first slot, and multiplexes and transmits the second sub-UCI in the Msg3 PUSCH on the second slot. The base station receives the first and second sub-UCIs transmitted in the first and second slots, respectively, and generates the total UCI bits. The base station then determines the number of times the Msg3 PUSCH should be transmitted based on the total UCI bits. Referring to Figure 24, the terminal transmits the Msg3 PUSCH by multiplexing a 1-bit UCI bit value of "0" or "1" for each slot. A UCI bit value of "0" indicates that the Msg3 PUSCH will be repeatedly transmitted in the slots following the slot in which the Msg3 PUSCH with a multiplexed UCI bit value of "0" is transmitted. A UCI bit value of "1" indicates that the slot in which the Msg3 PUSCH with a multiplexed UCI bit value of "1" is transmitted is the last slot in which the Msg3 PUSCH will be transmitted. Referring to Figure 24b, the terminal multiplexes the Msg3 PUSCH transmitted on the first slot with a UCI bit value of "0" because the Msg3 PUSCH will be repeatedly transmitted in the second slot (the slot after the first slot). The terminal multiplexes the Msg3 PUSCH transmitted on the second slot with a UCI bit value of "1" because the second slot is the last slot in which the Msg3 PUSCH will be repeatedly transmitted. Referring to Figure 24c, the terminal multiplexes the UCI bit value "0" for the Msg3 PUSCH transmitted on the first, second, and third slots, respectively. This is because the Msg3 PUSCH is transmitted repeatedly 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 multiplexes the UCI bit value "1" into the Msg3 PUSCH transmitted on the fourth slot. This is because the fourth slot is the last slot in which the Msg3 PUSCH is repeatedly transmitted. The method of multiplexing the UCI bit value "0" or "1" as explained in Figure 24 has a problem: if the base station cannot receive the Msg3 PUSCH with the UCI bit value "1" multiplexed into it, it cannot determine which slot will terminate the repeated transmission of the Msg3 PUSCH. For example, in Figure 24b, the number of times the Msg3 PUSCH is repeatedly transmitted is 2. In this case, if the base station cannot receive the Msg3 PUSCH transmitted on the second slot, it cannot confirm the UCI bit value "1," and therefore cannot determine which slot will terminate the repeated transmission of the Msg3 PUSCH.

[0248] The terminal multiplexes the UCI bit value "1" for Msg3 PUSCH transmitted over a specific number of consecutive slots. The specific number is a predetermined value determined based on the number of times Msg3 PUSCH is repeatedly transmitted. The specific number is half the number of times Msg3 PUSCH is repeatedly transmitted. Specifically, if Msg3 PUSCH is transmitted twice, the specific number is 1, and if Msg3 PUSCH is transmitted four times, the specific number is 2. In other words, if Msg3 PUSCH is transmitted R times, the specific number is f(R / 2). f(x) is a function that returns one of the following values ​​of x: truncated, rounded, or rounded up. The specific number of consecutive slots are selected from the slots where Msg3 PUSCH is last repeatedly transmitted. It is selected from the last slot where it is repeatedly transmitted. Referring to Figure 25c, Msg3 PUSCH is transmitted four times. The terminal transmits Msg3 PUSCH by multiplexing the UCI bit value "1" to each of the Msg3 PUSCH transmitted on two consecutive slots (the third and fourth slots) from the slot where Msg3 PUSCH was last repeatedly transmitted. Comparing Figure 24c and Figure 25c, in Figure 25c, once the base station confirms the multiplexed UCI bit value "1" in the Msg3 PUSCH transmitted on at least one of the third and fourth slots, the base station confirms that Msg3 PUSCH ends in the fourth slot.

[0249] According to the method described above, the UCI is multiplexed for each slot, thus reducing the number of REs used to transmit the Msg3 PUSCH. Therefore, the UCI should only be multiplexed in the fewest possible slots. For example, a base station will determine that a Msg3 PUSCH with a UCI bit value of "1" that has not been multiplexed is the same as one with a UCI bit value of "1" that has been multiplexed. As another example, a terminal multiplexes the UCI into the Msg3 PUSCH at regular intervals to transmit the Msg3 PUSCH. For example, a terminal bundles N slots in which the Msg3 PUSCH is repeatedly transmitted, and then multiplexes the UCI into the first slot of each bundle of N slots to transmit the Msg3 PUSCH. In this case, the bundled N slots are referred to as a slot bundle. If Msg3 PUSCH is repeatedly transmitted in slot bundles after the first slot bundle, the terminal multiplexes the Msg3 PUSCH transmitted on the (first) slot included in the first slot bundle with a UCI bit value of "0". If Msg3 PUSCH is not repeatedly transmitted in slot bundles after the first slot bundle, the terminal multiplexes the Msg3 PUSCH transmitted on the (first) slot included in the first slot bundle with a UCI bit value of "1". In other words, the first slot bundle is the slot bundle on which Msg3 PUSCH is last transmitted. Referring to Figure 26b, the terminal forms a slot bundle by bundling two slots. The terminal multiplexes the Msg3 PUSCH transmitted on the first slot in the first slot bundle with a UCI bit value of "1" because Msg3 PUSCH is not repeatedly transmitted in slot bundles after the first slot bundle. Referring to Figure 26c, the terminal forms a slot bundle by bundling two slots. The terminal multiplexes the UCI bit value "0" for the Msg3 PUSCH transmitted on the first slot of the initial bundle. This is because the Msg3 PUSCH is transmitted repeatedly in the second slot bundle (the slot bundle after the first slot bundle).The terminal multiplexes the UCI bit value "1" for the Msg3 PUSCH transmitted on the first slot of the two slot bundles. This is because the Msg3 PUSCH is not transmitted repeatedly in the slot bundles after the second slot bundle.

[0250] Slot determination method for repeatedly transmitting Msg3 PUSCH under TDD conditions The base station sets the symbol orientation for TDD operation.

[0251] The base station sets the cell-common symbol direction for terminals. The symbol direction is set by SIB1 transmitted to terminals within the cell. The base station sets the cell-common symbol direction using tdd-UL-DL-ConfigurationCommon in SIB1. The cell-common symbol direction is determined to be one of the following: UL symbol, DL symbol, or flexible symbol. A cell-common UL symbol is a symbol used only for uplink transmission. A cell-common DL symbol is a symbol used only for downlink transmission. A cell-common flexible symbol is a symbol whose direction is not determined and which can be changed to a UL symbol or DL ​​symbol by a separate setting.

[0252] The base station further sets a symbol direction specific to each terminal. The symbol direction specific to each terminal is set by RRC signaling during the random access process. Specifically, each terminal has its terminal-specific (UE-specific) symbol direction set by tdd-UL-DL-ConfigurationCommon. The direction of cell common UL symbols and cell common DL symbols is determined and cannot be further modified, and the direction of cell common flexible symbols is determined by the terminal-specific symbol direction. The terminal-specific symbol direction is determined to be one of the following: terminal-specific UL symbols, terminal-specific DL symbols, or terminal-specific flexible symbols. Terminal-specific UL symbols are symbols used only for uplink transmission. Terminal-specific DL symbols are symbols used only for downlink transmission. Terminal-specific flexible symbols are symbols whose specific direction is not determined and which can be changed to UL symbols or DL ​​symbols by separate settings.

[0253] Before receiving RRC signaling, the terminal sets the cell common symbol direction by the SIB1 it receives and repeatedly transmits Msg3 PUSCH. Therefore, the terminal should repeatedly transmit Msg3 PUSCH according to the cell common symbol direction. In this case, the terminal cannot determine whether or not the cell common flexible symbol can be used for the repeated transmission of Msg3 PUSCH. For example, a base station sets the cell common flexible symbol as the terminal-specific DL symbol for other terminals. In this case, if the terminal uses the cell common flexible symbol to repeatedly transmit Msg3 PUSCH, there is a risk of interference with other terminals. Therefore, it should be determined whether or not the cell common flexible symbol can be used for the repeated transmission of Msg3 PUSCH, and the method for determining this should be described below.

[0254] Figures 27 and 28 show resources available for repeated transmission of Msg3 PUSCH according to one embodiment of the present invention. In Figures 27 and 28, slot D refers to a slot containing a symbol that overlaps with a cell common DL symbol if at least one of the symbols scheduled to transmit Msg3 PUSCH overlaps with the cell common DL symbol. Slot U refers to a slot containing a symbol that overlaps with a cell common UL symbol if all of the symbols scheduled to transmit Msg3 PUSCH overlap with the cell common UL symbol. Slot F refers to a slot containing a symbol that overlaps with a cell common flexible symbol if at least one of the symbols scheduled to transmit Msg3 PUSCH overlaps with the cell common DL symbol (in this case, the symbol scheduled to transmit Msg3 PUSCH does not overlap with the cell common DL symbol, but overlaps with the cell common UL symbol).

[0255] Referring to Figure 27, the terminal is configured to repeatedly transmit Msg3 PUSCH on two consecutive slots. In this case, Msg3 PUSCH is transmitted in slots where transmission of Msg3 PUSCH is possible, and is dropped without transmission in slots where transmission of Msg3 PUSCH is not possible. i) Referring to Figure 27a, the terminal repeatedly transmits Msg3 PUSCH on the remaining slots except for slot D. That is, the terminal repeatedly transmits Msg3 PUSCH on slots F and U, and drops the PUSCH scheduled on slot D without transmission. However, there is a possibility that Msg3 PUSCH may be transmitted using the cell common flexible symbol and interfere with other terminals. ii) Referring to Figure 27b, the terminal repeatedly transmits Msg3 PUSCH only on slot U. That is, the terminal drops the Msg3 PUSCH scheduled on slots D and F without transmission. The terminal transmits Msg3 PUSCH using only UL symbols, thus avoiding interference with other terminals. iii) Referring to Figure 27c, the terminal performs the first transmission of the Msg3 PUSCH repetition in the slot designated by the uplink grant (i.e., the slot where the first transmission of the Msg3 PUSCH repetition takes place), and in the next slot, it repeatedly transmits Msg3 PUSCH only on the U slot. After the slot designated by the uplink grant, the terminal drops the Msg3 PUSCH scheduled for slots F and D without transmitting it. The slot designated by the uplink grant is determined based on the slot from which the uplink grant was received and the K2 value. The K2 value is a value set by the base station and represents the offset value from the slot from which the uplink grant was received. In other words, if the slot from which the uplink grant was received is the nth slot, then the slot designated by the uplink grant is the n+K2th slot. In this case, the slot designated by the uplink grant is either the F slot or the U slot. The base station is intentionally configured to use the cell-common flexible symbol for transmitting Msg3 PUSCH.

[0256] Referring to Figure 28, the terminal is configured to transmit Msg3 PUSCH four times, that is, to transmit it repeatedly on four slots. Therefore, the terminal should determine which four slots are capable of repeatedly transmitting Msg3 PUSCH. i) Referring to Figure 28a, the terminal determines that the remaining slots, excluding slot D, are capable of transmitting Msg3 PUSCH. In other words, the terminal repeatedly transmits Msg3 PUSCH on slots F and U. However, Msg3 PUSCH may be transmitted using the cell-common flexible symbol, potentially interfering with other terminals. ii) Referring to Figure 28b, the terminal repeatedly transmits Msg3 PUSCH only on slot U. In other words, the terminal cannot repeatedly transmit Msg3 PUSCH on slots F and U. Compared to the method described in Figure 28a (method i), although Msg3 PUSCH is repeatedly transmitted in slower slots, it has the effect of not interfering with other terminals because Msg3 PUSCH is repeatedly transmitted only on the U slot. iii) Referring to Figure 28c, the terminal performs the first transmission of the repeated Msg3 PUSCH in the slot designated by the uplink grant (i.e., the slot where the first transmission of the repeated Msg3 PUSCH is performed), and in the next slot, it repeatedly transmits Msg3 PUSCH only on the U slot. After the slot designated by the uplink grant, the terminal drops the Msg3 PUSCH scheduled for the F and D slots without transmitting it. The slot designated by the uplink grant is determined based on the slot from which the uplink grant was received and the K2 value. The K2 value is a value set by the base station and represents the offset value from the slot from which the uplink grant was received. In other words, if the slot where the uplink grant was received is the nth slot, then the slot indicated by the uplink grant is the n+K2th slot. In this case, the slot indicated by the uplink grant is either the F slot or the U slot. The base station intentionally configures the cell common flexible symbol to be used for transmitting Msg3 PUSCH.

[0257] The base station configures the uplink grant to use one of the methods described in Figures 27 and 28. The base station uses some bits of a specific field in the uplink grant to configure how to determine the slot in which Msg3 PUSCH is repeatedly transmitted, and the terminal repeatedly transmits Msg3 PUSCH based on the configured method. In the methods described in Figures 27 and 28, Msg3 PUSCH refers to the initial transmission of Msg3 PUSCH and the retransmission of Msg3 PUSCH.

[0258] In the above description, the cell common DL symbol further includes symbols with the Type-0 common search space (CSS) of CORESET0 set. Here, CORESET0 refers to the CORESET indicated by the PBCH. Here, the Type-0 common search space is a search space that monitors DCI format 1_0, which schedules the PDSCH that transmits SIB1. The DCI format has the CRC scrambled with SI-RNTI. In other words, the terminal considers symbols with the Type-0 CSS of CORESET0 set to receive as symbols that can only be received on the downlink.

[0259] The cell-common DL symbol further includes symbols with CORESET0's Type-0A CSS (common search space) configured. Type-0A CSS is a search space that monitors DCIs of DCI format 1_0 that schedule PDSCHs containing SIBs excluding SIB1. In this case, the DCI's CRC is scrambled with SI-RNTI. The cell-common DL symbol further includes symbols with CORESET0's Type-1 CSS configured. Type-1 CSS is a search space that monitors DCIs that schedule Msg2 PDSCHs or Msg4 PDSCHs. In this case, the DCI's CRC is scrambled with RA-RNTI, MsgB-RNTI, or TC-RNTI. The cell-common DL symbol further includes symbols with CORESET0's Type-2 CSS configured. Type-2 CSS is a search space that monitors DCIs that transmit paging information. In this case, the DCI is scrambled with CRC in P-RNTI. The cell-common DL symbol further includes symbols with Type-3 CSS set in CORESET0. Type-3 CSS is a search space for monitoring DCIs with various cell-common DCI formats. In this case, the DCI is scrambled with CRC in 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.

[0260] The cell-common DL symbol further includes symbols configured to receive SS / PBCH blocks. Symbols configured to receive SS / PBCH blocks are set by SIB1, specifically by SIB1's ssb-PositionsInBurst. In other words, the terminal determines that symbols configured to receive SS / PBCH blocks are symbols that can only be received on the downlink channel.

[0261] The cell common UL symbol further includes symbols configured for PRACH transmission. Symbols configured for PRACH transmission are symbols corresponding to valid RACH occasions (ROs). The terminal receives the PRACH configuration from the base station via SIB1. Specifically, the PRACH configuration is set by rach-ConfigCommon in the initialUplinkBWP of the UplinkConfigCommonSIB of the ServingCellConfigCommonSIB of SIB1. The terminal determines valid ROs based on the PRACH configuration. The method for determining valid ROs is described below.

[0262] a. If tdd-UL-DL-ConfigurationCommon is not set on the terminal, it will not precede the SS / PBCH block and will start from the last symbol of the SS / PBCH block. gap ROs that are more than a symbol's distance away are determined to be valid ROs.

[0263] If b.tdd-UL-DL-ConfigurationCommon is set on the terminal, all RO symbols will be superimposed with the cell common UL symbols, or RO will not precede the SS / PBCH block, and will start from the last symbol of the SS / PBCH block. gap ROs that are more than a symbol's distance away are determined to be valid ROs.

[0264] The terminal transmits PRACH using a valid RO. In other words, the base station assumes that a valid RO is used for uplink channel transmission. The cell common UL symbol is the N before a valid RO. gap Includes symbols. In this case, the symbols for which PRACH transmission is scheduled are the symbols corresponding to valid ROs. The terminal is N gap This is because the symbol does not receive the downlink channel or signal. Therefore, the terminal N gap The symbol is assumed to be used for uplink transmission. gapThis value is 0 if the subcarrier interval of PRACH is 1.25 kHz or 5 kHz, and 2 if it is 15 kHz, 30 kHz, 60 kHz, or 120 kHz.

[0265] Frequency hopping method for repeated transmission of uplink channels The following describes the frequency hopping method applied when a terminal repeatedly transmits data on the uplink channel.

[0266] The base station configures long PUCCH (i.e., PUCCH formats 1, 3, and 4) to be transmitted repeatedly in 2, 4, or 8 slots for terminal PUCCH coverage. When a terminal enters RRC_CONNECTED mode after its initial cell access, the terminal is configured with PUCCH repetition counts (nrofSlots) for each PUCCH format based on terminal-specific system information. For example, if the PUCCH formats transmitted over the configured resources include PUCCH formats 1, 3, and 4, the repetition counts for each PUCCH format will be set to different PUCCH repetition counts (nrofSlots).

[0267] If a terminal is configured to transmit PUCCH N times, then N slots capable of transmitting PUCCH are determined sequentially, starting from the slot in which PUCCH transmission is configured or instructed. Slots capable of transmitting PUCCH must not have symbols scheduled to transmit PUCCH within the slot overlapping with symbols configured to receive semi-static DL symbols or SS / PBCH blocks. If symbols scheduled to transmit PUCCH overlap with symbols configured to receive semi-static DL symbols or SS / PBCH blocks, the terminal will not transmit PUCCH in that slot, and that slot will not be included in the N slots for PUCCH transmission.

[0268] Before the terminal completes the repeated transmission of the PUCCH for the number of times of repeated transmission of the PUCCH preset by the base station, a new repeated transmission of the PUCCH is set by the base station. When the terminal enters the RRC connected mode after the first cell access, the terminal is set to repeatedly transmit the PUCCH N times according to the terminal-specific system information. Next, if the channel environment improves, the terminal is newly set to repeatedly transmit the PUCCH M (<N) times to reduce the overhead of the uplink control channel and uplink interference. Conversely, if the channel environment deteriorates, the terminal is newly set to repeatedly transmit the PUCCH M (>N) times to increase the coverage of the uplink control channel. Here, the number of repeated transmissions (M) includes 1. That is, when the terminal receives the setting for the repeated transmission of the new PUCCH, it ignores the setting for the repeated transmission of the previously set PUCCH and repeatedly transmits the new PUCCH based on the setting for the repeated transmission of the new PUCCH.

[0269] The terminal receives explicit information from the base station to determine the number of repetitions for a new PUCCH. The explicit information is the number of repetitions for the PUCCH. The explicit information is included in the DCI that contains the PDCCH that schedules the corresponding PDSCH. The PDSCH corresponding to the PUCCH is the PUCCH that contains the HARQ-ACK information for that PDSCH. The explicit information is indicated by the size of ceil(log2(K)) bits, where K is the number of repetitions for the configurable PUCCH. For example, when the number of repetitions for the configurable PUCCH is 1, 2, 4, and 8, K=4, so it is indicated as ceil(log2(4))=2 bits. The number of repetitions for the configurable PUCCH is one of {1, 2, 4, 8}. The base station sets the number of repetitions for multiple PUCCHs from the number of repetitions for the configurable PUCCHs as explicit information. For example, the base station sets {2 and 4} as explicit information from the PUCCH repeat transmission count {1, 2, 4, 8}. The number of repeat transmission counts for a controllable PUCCH is one of {1, 2, 4, 8, N}. N is a value pre-set for each PUCCH format. The base station sets the repeat transmission counts for multiple PUCCHs as explicit information from the number of repeat transmission counts for controllable PUCCHs. In this case, the number of repeat transmission counts for multiple PUCCHs set as explicit information includes N. For example, the base station sets {2 and N} as explicit information from the PUCCH repeat transmission count {1, 2, 4, 8, N}. The number of repeat transmission counts for a controllable PUCCH is one of {N / 4, N / 2, N, 2*N, 4*N}. In this case, the base station sets {N / 2, N} as the PUCCH repeat transmission count. If N / 4 is explicitly set, the terminal will repeatedly transmit PUCCH a number of times equal to 1 / 4 of the pre-set N (i.e., if N=4, it will repeat once; if N=8, it will repeat twice). Similarly, if N / 2 is explicitly set, the terminal will repeatedly transmit PUCCH a number of times equal to 1 / 2 of the pre-set N (i.e., if N=2, it will repeat once; if N=4, it will repeat twice; if N=8, it will repeat four times).If 2*N is explicitly set as information, the terminal will repeatedly transmit PUCCH twice the number of times N (i.e., if N=1, it will be repeated 2 times; if N=2, 4 times; if N=4, 8 times). If 4*N is explicitly set as information, the terminal will repeatedly transmit PUCCH four times the number of times N (i.e., if N=1, 4 times; if N=2, 8 times). If N / 4 and N / 2 are less than 1, the number of repeated PUCCH transmissions is 1. If 2*N and 4*N are greater than 8, the number of repeated PUCCH transmissions is 8.

[0270] Previously, the number of repeated transmissions of a PUCCH was set to differ depending on the PUCCH format. When a new resource for transmitting a PUCCH is set on a terminal, and the terminal attempts to repeatedly transmit a new PUCCH, if the previous PUCCH format and the newly set PUCCH format are the same, the terminal will repeatedly transmit the newly set PUCCH the number of times corresponding to the PUCCH format. For example, a PUCCH format transmitted by a resource with a PUCCH resource ID set to 0 is PUCCH format 1, with a transmission count of 8, while a PUCCH format transmitted by a resource with a PUCCH resource ID set to 1 is also PUCCH format 1, with a transmission count of 2. Next, if the PUCCH resource ID indicated by 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 will repeatedly transmit a PUCCH of PUCCH format 1 in 8 slots, and if the PUCCH resource ID is 1, the terminal will repeatedly transmit a PUCCH of PUCCH format 1 in 2 slots. The number of times a PUCCH message is repeatedly transmitted for each resource is one of the following values: {1, 2, 4, 8}. On the other hand, if the number of times a PUCCH message is repeatedly transmitted is not set for the resource to which the PUCCH message is transmitted, the terminal will repeatedly transmit the PUCCH message according to the number of times set by the PUCCH format.

[0271] The following describes how the base station configures frequency hopping when the terminal is set to allow repeated transmission of PUCCH.

[0272] Intra-slot frequency hopping The terminal divides the PUCCH in half in the time domain, matches it with two hops within the slot configured to transmit the PUCCH, and transmits the two hops to the base station. In this case, the PUCCH may or may not be transmitted repeatedly. If the length (number) of symbols allocated to transmit the PUCCH in one slot is denoted by number of symbols, then floor(number of symbols / 2) symbols are matched in the first hop, and number of symbols-floor(number of symbols / 2) symbols are matched in the second hop. The first hop is transmitted on the first frequency band, and the second hop is transmitted on the second frequency band. The PRB of the first hop consists of PRBs ranging from the PRB corresponding to the starting PRB index set by the base station to the number of PRBs set by the base station. The PRB of the second hop consists of PRBs ranging from the PRB corresponding to the PRB index where the second hop starts, to the number of PRBs set by the base station.

[0273] Inter-slot frequency hopping The slot index for repetition is sequentially indexed based on the slot in which the first PUCCH is transmitted. The slot in which the first PUCCH is transmitted has a repetition index of 0. The repetition slot index is then sequentially indexed for slots after the slot in which the first PUCCH is transmitted. The repetition slot index is determined regardless of whether or not repetition of the PUCCH is possible on the corresponding slot. For example, if a terminal is configured to transmit a PUCCH four times in slot X, the terminal determines the index for slot X to be 0, the index for slot X+1 to be 1, the index for slot X+2 to be 2, and the index for slot X+3 to be 3. Based on the determined repetition slot index, the terminal maps the PUCCH to the first hop in the slot corresponding to the even-numbered repetition slot index. The terminal maps the PUCCH to the second hop in the slot corresponding to the odd-numbered repetition slot index. The first hop is transmitted on the first frequency band, and the second hop is transmitted on the second frequency band. The PRB for the first hop consists of PRBs ranging from the PRB corresponding to the starting PRB index set by the base station to the number of PRBs set by the base station. The PRB for the second hop consists of PRBs ranging from the PRB corresponding to the PRB index where the second hop begins, to the number of PRBs set by the base station.

[0274] PUCCH frequency hopping method The base station sets either intra-slot frequency hopping or inter-slot frequency hopping on the terminal.

[0275] The base station sets whether or not intra-slot frequency hopping is possible for each resource on which PUCCH transmission is configured. For example, if a terminal is configured with a resource whose PUCCH resource set ID is 1 within a resource set whose PUCCH resource set ID is 0, the base station sets whether or not intra-slot frequency hopping is possible. If the base station is configured to allow intra-slot frequency hopping, the terminal transmits the PUCCH via intra-slot frequency hopping; if the base station is configured to disallow intra-slot frequency hopping, the terminal transmits the PUCCH without intra-slot frequency hopping.

[0276] The base station sets whether inter-slot frequency hopping is possible for each PUCCH format. For example, the base station sets whether inter-slot frequency hopping is possible for a PUCCH of PUCCH format 1. If the base station is set to allow inter-slot frequency hopping, the terminal transmits the PUCCH via inter-slot frequency hopping regardless of the resource on which the PUCCH is set. If the base station is set to not allow inter-slot frequency hopping, the terminal transmits the PUCCH using the resource on which the PUCCH is set. In other words, the terminal transmits the PUCCH depending on whether inter-slot frequency hopping is possible, which is set for each resource on which the PUCCH is transmitted.

[0277] If a terminal is configured to allow inter-slot frequency hopping for a specific PUCCH format, it expects that the resource transmitting the PUCCH in that specific PUCCH format will not be configured for inter-slot frequency hopping. In other words, if a base station is configured to allow inter-slot frequency hopping using a PUCCH format, it will not configure the resource transmitting the PUCCH for intra-slot frequency hopping.

[0278] The base station sets the first repeatedly transmitted PUCCH of a specific PUCCH format to have a transmission count (N) greater than 1 and to allow intra-slot hopping. Next, the terminal sets the transmission count of a new PUCCH to 1. At this point, since intra-slot hopping is enabled, the terminal does not expect the PUCCH to be configured to allow inter-slot frequency hopping. In other words, if a PUCCH of a specific PUCCH format is configured to perform inter-slot frequency hopping, the new PUCCH will not be transmitted via intra-slot frequency hopping, regardless of its transmission count. Therefore, a method is needed to determine the frequency hopping method based on the transmission count of a new PUCCH.

[0279] Figure 29 shows a method for determining the frequency hopping method based on the number of repeated transmissions of PUSCH according to one embodiment of the present invention.

[0280] The terminal determines the frequency hopping method by interpreting the upper layer fields differently depending on the number of repetitions of the new PUCCH transmission. Specifically, the terminal interprets the intra-slot frequency hopping or inter-slot frequency hopping value in the upper layer fields depending on whether the number of PUCCH repetitions is 1 or not. Referring to Figure 29, nrofSlots indicates the number of PUCCH repetitions composed of base stations, and intraSlotFrequencyHopping indicates whether intra-slot frequency hopping is possible or not. If intraSlotFrequencyHopping is set to enabled, intra-slot frequency hopping is performed; otherwise, intra-slot frequency hopping is not performed. interSlotFrequencyHopping indicates whether inter-slot frequency hopping is performed or not. If interSlotFrequencyHopping is set to enabled, inter-slot frequency hopping is performed; otherwise, inter-slot frequency hopping is not performed. If the number of repetitions of the new PUCCH transmission is 1, the terminal checks whether intra-slot frequency hopping is enabled, regardless of whether inter-slot frequency hopping is enabled in the upper layer. If intra-slot frequency hopping is enabled, the terminal transmits a new PUCCH using intra-slot frequency hopping. If the number of repeated transmissions of a new PUCCH is not 1, the terminal first checks if inter-slot frequency hopping is enabled at the higher layer. If inter-slot frequency hopping is enabled, the terminal repeatedly transmits a new PUCCH using inter-slot frequency hopping. In this case, the PUCCH is transmitted using only inter-slot frequency hopping, regardless of whether intra-slot frequency hopping is enabled or not. If inter-slot frequency hopping is not enabled, the terminal checks if intra-slot frequency hopping is enabled at the higher layer.If intra-slot frequency hopping is enabled, the terminal repeatedly transmits new PUCCHs by performing intra-slot frequency hopping; if intra-slot frequency hopping is not enabled, the terminal repeatedly transmits PUCCHs without frequency hopping.

[0281] In other words, the terminal is configured to allow inter-slot frequency hopping for each PUCCH format. The terminal is configured to allow intra-slot frequency hopping for each resource configured to transmit PUCCH. Alternatively, the terminal is configured to set the number of repeated PUCCH transmissions. Based on the number of repeated transmissions, the terminal determines whether inter-slot frequency hopping is possible for the resource configured to transmit PUCCH. If the number of repeated transmissions is 1, inter-slot frequency hopping does not occur. If the number of repeated transmissions is greater than 1 and inter-slot frequency hopping is enabled by the PUCCH format, the terminal performs inter-slot frequency hopping regardless of whether intra-slot frequency hopping is enabled or disabled. Conversely, if the number of repeated transmissions is greater than 1 and inter-slot frequency hopping is disabled by the PUCCH format, the terminal performs frequency hopping depending on whether intra-slot frequency hopping is enabled or disabled.

[0282] PUSCH's frequency hopping method The following describes the frequency hopping method for PUSCH. The frequency hopping method for PUSCH is set from the top level upwards.

[0283] For example, the terminal determines the 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 repetitions of the new PUSCH. In this case, the DCI is the DCI of the PDCCH that schedules the PUSCH. More specifically, the terminal interprets the 1-bit size frequency hopping flag differently depending on whether the number of repetitions of the new PUSCH is 1 or not. i) If the number of repetitions of the new PUSCH set by the terminal is 1 and the bit value of the frequency hopping flag is 0, the terminal transmits the PUSCH without performing frequency hopping. ii) If the number of repetitions of the new PUSCH set by the terminal is 1 and the bit value of the frequency hopping flag is 1, the terminal transmits the PUSCH by performing intra-slot frequency hopping. iii) If the number of repetitions of the new PUSCH set by the terminal is greater than 1 and the bit value of the frequency hopping flag is 0, the terminal transmits the PUSCH by performing intra-slot frequency hopping. iv) If the number of repetitions of a newly configured PUSCH is greater than 1 and the bit value of the frequency hopping flag is 1, the terminal repeatedly transmits the PUSCH by frequency hopping between slots. As another example, i) If the number of repetitions of a newly configured PUSCH is 1 and the bit value of the frequency hopping flag is 0, the terminal transmits the PUSCH without frequency hopping. ii) If the number of repetitions of a newly configured PUSCH is 1 and the bit value of the frequency hopping flag is 1, the terminal transmits the PUSCH by frequency hopping within a slot. iii) If the number of repetitions of a newly configured PUSCH is greater than 1 and the bit value of the frequency hopping flag is 0, the terminal repeatedly transmits the PUSCH without frequency hopping. iv) If the number of repetitions of a newly configured PUSCH is greater than 1 and the bit value of the frequency hopping flag is 1, the terminal repeatedly transmits the PUSCH by frequency hopping between slots.

[0284] The terminal sets the number of repetitions and frequency hopping method for a new PUSCH as a pair, and determines the number of repetitions and frequency hopping method for 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 is the DCI of the PDCCH that schedules the PUSCH. Specifically, the terminal transmits the new PUSCH after the base station sets the number of repetitions and frequency hopping method for the new PUSCH as a pair (i.e., number of repetitions, hopping method) based on the DCI corresponding to the new PUSCH. In this case, up to two (number of repetitions, hopping method) can be set. In this case, the hopping method is one of three cases: intra-slot frequency hopping, inter-slot frequency hopping, and no frequency hopping.

[0285] Msg3 PUSCH frequency hopping method The new PUSCH described above is a new Msg3 PUSCH scheduled by the uplink grant of the random access response. The number of transmissions of the new Msg3 PUSCH is included in the uplink grant. The frequency hopping method when the new Msg3 PUSCH is repeatedly transmitted is described below.

[0286] The base station sets the frequency hopping method for repeated transmission of new Msg3 PUSCHs for frequency diversification gain. The frequency hopping method is set by a single bit value of the frequency hopping flag in the uplink grant of the random access response that schedules the new Msg3 PUSCH. For retransmitted Msg3 PUSCHs, the frequency hopping method is set by a single bit value of the frequency hopping flag in the DCI of the TC-RNTI-scrambled DCI format 0_0 that schedules the retransmitted Msg3 PUSCH. If the bit value of the frequency hopping flag is 0, the terminal repeatedly transmits the new Msg3 PUSCH without frequency hopping; if the bit value of the frequency hopping flag is 2, the terminal repeatedly transmits the new Msg3 PUSCH with intra-slot frequency hopping. When a terminal repeatedly transmits Msg3 PUSCHs, inter-slot frequency hopping is more advantageous than intra-slot frequency hopping in terms of DMRS overhead if inter-slot frequency hopping is possible. The following describes how the terminal repeatedly transmits new Msg3 PUSCH messages by performing inter-slot frequency hopping.

[0287] The terminal interprets the bits of the frequency hopping flag based on the number of times the new Msg3 PUSCH has been repeatedly transmitted to determine the frequency hopping method. Specifically, the terminal interprets the frequency hopping flag differently than before depending on whether the number of times the new Msg3 PUSCH has been repeatedly transmitted is 1 or not. For example, i) If the number of times the new Msg3 PUSCH set by the terminal is 1 and the bit value of the frequency hopping flag is 0, the terminal repeatedly transmits the Msg3 PUSCH without performing frequency hopping. ii) If the number of times the new Msg3 PUSCH set by the terminal is 1 and the bit value of the frequency hopping flag is 1, the terminal performs intra-slot frequency hopping to transmit the new Msg3 PUSCH. iii) If the number of times the new Msg3 PUSCH set by the terminal is greater than 1 and the bit value of the frequency hopping flag is 0, the terminal performs intra-slot frequency hopping to repeatedly transmit the new Msg3 PUSCH. iv) If the number of repetitions of the new Msg3 PUSCH set by the terminal is greater than 1 and the bit value of the frequency hopping flag is 1, the terminal performs inter-slot frequency hopping to repeatedly transmit the new Msg3 PUSCH. As another example, i) If the number of repetitions of the new Msg3 PUSCH set by the terminal is 1 and the bit value of the frequency hopping flag is 0, the terminal transmits the new Msg3 PUSCH without frequency hopping. ii) If the number of repetitions of the new Msg3 PUSCH set by the terminal is 1 and the bit value of the hopping flag is 1, the terminal performs intra-slot frequency hopping to transmit the new Msg3 PUSCH. iii) If the number of repetitions of the new Msg3 PUSCH set by the terminal is greater than 1 and the bit value of the frequency hopping flag is 0, the terminal decides to repeatedly transmit the new Msg3 PUSCH without frequency hopping. iv) If the number of times the new Msg3 PUSCH set by the terminal has been repeatedly transmitted is greater than 1, and the bit value of the frequency hopping flag is 1, the terminal performs inter-slot frequency hopping to repeatedly transmit the new Msg3 PUSCH.

[0288] The terminal is configured with a pair of repeat transmission counts and frequency hopping methods for a new Msg3 PUSCH, and determines the repeat transmission counts and frequency hopping methods for the new Msg3 PUSCH by interpreting the bits of the frequency hopping flag differently. More specifically, the terminal transmits the new Msg3 PUSCH with the repeat transmission counts and frequency hopping methods for the new PUSCH configured in the form of a pair (i.e., repeat transmission count, hopping method) by the DCI corresponding to the new PUSCH from the base station. More specifically, the pair indicating the repeat transmission counts and frequency hopping methods for the new PUSCH is determined by the frequency hopping flag of the uplink grant or DCI in DCI format 0_0 of the random access response scheduling the Msg3 PUSCH. In this case, up to two (repeat transmission count, hopping method) can be configured. In this case, the hopping method is one of three cases: intra-slot frequency hopping, inter-slot frequency hopping, and no frequency hopping.

[0289] Figure 30 is a flowchart showing how a terminal according to one embodiment of the present invention transmits Msg3 PUSCH.

[0290] The following describes how the terminal described in Figures 1 to 29 transmits Msg3 PUSCH, with reference to Figure 30.

[0291] S3010 The terminal receives System Information Block 1 (SIB1) from the base station. In this case, System Information Block 1 is another System Information Block as described above (for example, SIBx, x=1, 2, 3, ...). S3020 The terminal transmits a preamble for a random access procedure to the base station. S3030 The terminal receives 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) to be transmitted by the terminal to the base station. S3040 The terminal transmits the PUSCH to the base station based on the Random Access Response. SIB1 includes information about a candidate set of repeat transmission counts, which includes values ​​for one or more repeat transmission counts for repeatedly transmitting the PUSCH. The Random Access Response includes information indicating one of the values ​​for the one or more repeat transmission counts included in the candidate set of repeat transmission counts. The PUSCH is transmitted repeatedly only by one of these values. The random access response is a physical downlink shared channel (PDSCH) including an uplink (UL) grant. The information indicating any one of the aforementioned values ​​is included in at least one of the time-domain resource allocation (TDRA) field, modulation coding scheme (MCS) field, and transmission power control (TPC) field of the random access response. If the information indicating any one of the aforementioned values ​​is included in the MCS field, then the aforementioned value is indicated by one or more MSBs of the MCS field. On the other hand, if the information indicating any one of the aforementioned values ​​is included in the TPC field, then the aforementioned value is indicated by one or more LSBs of the TPC field. Each of the values ​​for the one or more repeated transmission counts is a power of 2. Specifically, the values ​​for the one or more repeated transmission counts are 1, 2, 4, and 8. The SIB1 includes at least one of the preamble information and the RACH opportunity. The PUSCH is transmitted over a resource determined based on either the preamble information or the RACH opportunity.

[0292] After S3040, the terminal receives downlink control information (DCI) from the base station, which includes information for scheduling a retransmission PUSCH. The terminal repeatedly transmits the retransmission PUSCH to the base station based on the DCI. In this case, the information for scheduling the retransmission PUSCH includes information regarding the number of repetitions of the retransmission PUSCH. The information regarding the number of repetitions of the retransmission PUSCH is included in the HARQ process number field of the DCI. The retransmission PUSCH is the same as the PUSCH transmitted by the terminal in S3040. The DCI is transmitted by the base station if the base station fails to receive the PUSCH transmitted by the terminal. In other words, if the base station fails to receive the PUSCH transmitted by the terminal in S3040, it transmits information to the terminal for scheduling the retransmission PUSCH.

[0293] The random access response includes a frequency hopping flag indicating whether the PUSCH will frequency hop or not. The PUSCH frequency hops within a slot or between slots based on either of the above values ​​and the frequency hopping flag. If either of the above values ​​is 1, the PUSCH frequency hops within a slot if the value of the frequency hopping flag indicates that the PUSCH will frequency hop. If the value of the frequency hopping flag indicates that the PUSCH will not frequency hop, the PUSCH will not frequency hop. On the other hand, if either of the above values ​​is greater than 1, the PUSCH frequency hops between slots if the value of the frequency hopping flag indicates that the PUSCH will frequency hop. If the value of the frequency hopping flag indicates that the PUSCH will not frequency hop, the PUSCH will not frequency hop. In this case, the PUSCH is a retransmission PUSCH.

[0294] The random access response further includes information about the resource on which the first repeated transmission of the PUSCH takes place. The information about the resource on which the first repeated transmission of the PUSCH takes place is a slot offset value between the resource that received the random access response and the resource on which the first repeated transmission of the PUSCH takes place. The SIB1 further includes information about the configuration of the TDD, which is information about the type of symbols that make up the slots. The type of symbol is one of the following: 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 a downlink symbol or an uplink symbol. The PUSCH is transmitted repeatedly in slot units. The resource on which the first repeated transmission of the PUSCH takes place is a resource that is separated from the resource that received the random access response by the slot offset value. The resource on which the first repeated transmission of the PUSCH takes place is a flexing slot, and subsequent repeated transmissions after the first repeated transmission of the PUSCH take place on uplink slots. The flexible symbol is composed of at least one of the flexible symbols, and each of the uplink slots is composed of the uplink symbol. In this case, the PUSCH is a retransmission PUSCH.

[0295] The terminal that performs the method described with reference to Figure 30 is the terminal described in Figure 11. More specifically, the terminal comprises a communication module for sending and receiving wireless signals and a processor for controlling the communication mode. In this case, the terminal's processor performs the method of transmitting Msg3 PUSCH as described herein.

[0296] Furthermore, the base station that receives the Msg3 PUSCH transmitted by the terminal described herein is configured to include a communication module for sending and receiving radio signals and a processor for controlling the communication mode. In this case, the base station is the base station described in Figure 11. In this case, the processor of the base station performs the method for receiving the Msg3 PUSCH transmitted by the terminal described herein.

[0297] Although the methods and systems of the present invention have been described in relation to specific embodiments, some or all of their components or operations may be embodied by computing systems having a general-purpose hardware architecture.

[0298] The above description of the present invention is illustrative, and a person with ordinary skill in the art to which the present invention pertains will understand that it can be easily modified into other specific forms without altering the technical idea or essential features of the present invention. Accordingly, the embodiments described above should be understood in all respects as illustrative and not limiting. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined manner.

[0299] The scope of the present invention is defined more by the attached claims than by the above detailed description, and any modified or altered forms derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included within the scope of the present invention. [Explanation of symbols]

[0300] 100 devices 110 processors 120 Communication Modules 121 Cellular Communication Interface Card 122 Cellular Communication Interface Card 123 Unlicensed Bandwidth Communication Interface Card 130 memory 140 User Interfaces 150 display units 200 base stations 210 processors 220 Communication Module 221 Cellular Communication Interface Card 222 Cellular Communication Interface Card 223 Unlicensed Bandwidth Communication Interface Card 230 memory

Claims

1. In a method used by user equipment in a wireless communication system, the method is: Steps include receiving a set of one or more values ​​for the number of Physical Uplink Shared Channel (PUSCH) iterations via upper-layer signaling, Steps include transmitting a preamble for a random access procedure, The steps include receiving a Random Access Response (RAR) for the preamble, The step of transmitting the PUSCH repetition corresponding to one value in the set based on the RAR, The aforementioned value is indicated by the two bits of the Most Significant Bit (MSB) in the Modulation Coding Scheme (MCS) field of the RAR. The RAR includes information related to an offset k for determining the slot in which the PUSCH repetition is performed, and a frequency hopping flag indicating whether or not the PUSCH repetition is transmitted by frequency hopping. Slot n is the last slot from which the RAR is received. The aforementioned PUSCH repetition is transmitted by starting from the start slot. The starting slot is determined based on slot n+k, If the aforementioned one value is 1, If the frequency hopping flag indicates that the PUSCH repetition is transmitted without frequency hopping, then the PUSCH repetition is transmitted without frequency hopping. If the frequency hopping flag indicates that the PUSCH repetition is transmitted by frequency hopping, then the PUSCH repetition is transmitted by intra-slot frequency hopping. If the aforementioned value is 2 or more, If the frequency hopping flag indicates that the PUSCH repetition is transmitted without frequency hopping, then the PUSCH repetition is transmitted without frequency hopping. If the frequency hopping flag indicates that the PUSCH repetition is transmitted by frequency hopping, then the PUSCH repetition is transmitted by inter-slot frequency hopping. The method is characterized in that the resources for transmitting the PUSCH repetitions do not include downlink symbols, and the downlink symbols are configured in common across cells by the upper-layer signaling.

2. The method according to claim 1, characterized in that the RAR is received via a Physical Downlink Shared Channel (PDSCH), and the RAR includes an Uplink (UL) grant.

3. The method according to claim 1, characterized in that the upper layer signaling includes a System Information Block 1 (SIB1).

4. Downlink control information for scheduling of retransmission PUSCH The steps include receiving Control Information (DCI), The further step includes transmitting the retransmission PUSCH based on the DCI, The method according to claim 1, characterized in that the DCI includes information regarding the number of retransmissions of the PUSCH.

5. The aforementioned DCI is scrambled with TC-RNTI (Temporary Cell-Radio Network Temporary Identifier), The method according to claim 4, characterized in that the DCI format is DCI format 0_0.

6. The method according to claim 1, characterized in that the one or more values ​​include powers of 2.

7. The method according to claim 1, characterized in that the PUSCH repetition is transmitted in slot units.

8. In a user device configured to operate in a wireless communication system, the user device is: Transmitter and receiver, A processor that controls the transceiver, The aforementioned processor, The Physical Uplink Shared Channel (PUSCH) receives a set of one or more values ​​for the number of iterations via upper-layer signaling. Transmit a preamble for a random access procedure, Upon receiving a Random Access Response (RAR) for the aforementioned preamble, Based on the RAR, the PUSCH repetition corresponding to one value in the set is transmitted. The aforementioned value is indicated by the two bits of the Most Significant Bit (MSB) in the Modulation Coding Scheme (MCS) field of the RAR. The RAR includes information related to an offset k for determining the slot in which the PUSCH repetition is performed, and a frequency hopping flag indicating whether or not the PUSCH repetition is transmitted by frequency hopping. Slot n is the last slot from which the RAR is received. The aforementioned PUSCH repetition is transmitted by starting from the start slot. The starting slot is determined based on slot n+k, If the aforementioned one value is 1, If the frequency hopping flag indicates that the PUSCH repetition is transmitted without frequency hopping, then the PUSCH repetition is transmitted without frequency hopping. If the frequency hopping flag indicates that the PUSCH repetition is transmitted by frequency hopping, then the PUSCH repetition is transmitted by intra-slot frequency hopping. If the aforementioned value is 2 or more, If the frequency hopping flag indicates that the PUSCH repetition is transmitted without frequency hopping, then the PUSCH repetition is transmitted without frequency hopping. If the frequency hopping flag indicates that the PUSCH repetition is transmitted by frequency hopping, then the PUSCH repetition is transmitted by inter-slot frequency hopping. The user device is characterized in that the resources for transmitting the PUSCH repetition do not include downlink symbols, and the downlink symbols are configured in common across cells by the upper-layer signaling.

9. The user equipment according to claim 8, characterized in that the RAR is received via a Physical Downlink Shared Channel (PDSCH), and the RAR includes an Uplink (UL) grant.

10. The user device according to claim 8, characterized in that the upper layer signaling includes a System Information Block 1 (SIB1).

11. The user device according to claim 8, characterized in that one or more of the aforementioned values ​​include powers of 2.

12. The user device according to claim 8, characterized in that the PUSCH repetition is transmitted in slot units.

13. In a method used by a base station in a wireless communication system, the method is: The steps include transmitting a set of one or more values ​​for the number of repetitions of a Physical Uplink Shared Channel (PUSCH) via upper-layer signaling, A step of receiving a preamble for a random access procedure, The steps include transmitting a random access response (RAR) to the preamble, The step of receiving the PUSCH repetition corresponding to one value in the set based on the RAR, The aforementioned value is indicated by the two bits of the Most Significant Bit (MSB) in the Modulation Coding Scheme (MCS) field of the RAR. The RAR includes information related to an offset k for determining the slot in which the PUSCH repetition is performed, and a frequency hopping flag indicating whether or not the PUSCH repetition is transmitted by frequency hopping. Slot n is the last slot from which the RAR is received. The aforementioned PUSCH repetition is transmitted by starting from the start slot. The starting slot is determined based on slot n+k, If the aforementioned one value is 1, If the frequency hopping flag indicates that the PUSCH repeat is received without frequency hopping, then the PUSCH repeat is transmitted without frequency hopping. If the frequency hopping flag indicates that the PUSCH repeat is received via frequency hopping, then the PUSCH repeat is transmitted via intra-slot frequency hopping. If the aforementioned value is 2 or more, If the frequency hopping flag indicates that the PUSCH repeat is received without frequency hopping, then the PUSCH repeat is transmitted without frequency hopping. If the frequency hopping flag indicates that the PUSCH repeat is received via frequency hopping, then the PUSCH repeat is transmitted via inter-slot frequency hopping. The method is characterized in that the resources for transmitting the PUSCH repetitions do not include downlink symbols, and the downlink symbols are configured in common across cells by the upper-layer signaling.

14. In a base station configured to operate in a wireless communication system, the base station is: Transmitter and receiver, A processor that controls the transceiver, The aforementioned processor, Transmitting a set of one or more values ​​for the number of repetitions of a Physical Uplink Shared Channel (PUCH) via upper-layer signaling, Receive a preamble for a random access procedure, A random access response (RAR) is transmitted to the aforementioned preamble. Based on the RAR, receive the repetition of the PUSCH corresponding to one value in the set, The aforementioned value is indicated by the two bits of the Most Significant Bit (MSB) in the Modulation Coding Scheme (MCS) field of the RAR. The RAR includes information related to an offset k for determining the slot in which the PUSCH repetition is performed, and a frequency hopping flag indicating whether or not the PUSCH repetition is transmitted by frequency hopping. Slot n is the last slot from which the RAR is received. The aforementioned PUSCH repetition is transmitted by starting from the start slot. The starting slot is determined based on slot n+k, If the aforementioned one value is 1, If the frequency hopping flag indicates that the PUSCH repeat is received without frequency hopping, then the PUSCH repeat is transmitted without frequency hopping. If the frequency hopping flag indicates that the PUSCH repeat is received via frequency hopping, then the PUSCH repeat is transmitted via intra-slot frequency hopping. If the aforementioned value is 2 or more, If the frequency hopping flag indicates that the PUSCH repeat is received without frequency hopping, then the PUSCH repeat is transmitted without frequency hopping. If the frequency hopping flag indicates that the PUSCH repeat is received via frequency hopping, then the PUSCH repeat is transmitted via inter-slot frequency hopping. The base station is characterized in that the resources for transmitting the PUSCH repetitions do not include downlink symbols, and the downlink symbols are configured in common to the cell by the upper layer signaling.

Images