Method and apparatus for transmitting signals in a wireless communication system

Abstract

The present invention relates to a wireless communication system, and more particularly to a step of receiving a cell-specific RRC signal related to a slot format, the slot format including information on a type of symbol, the type of symbol including at least one of a DL symbol, a flexible symbol, and an UL symbol; and a step of determining whether an RO in a PRACH slot is valid, the determination being made if the RO is at least N symbols from the last DL symbol. gap The present invention relates to a method and a wireless device therefor, comprising: a step of determining whether the RO is valid based on whether it starts after a symbol; and a step of performing UL transmission or DL ​​reception based on whether the RO is valid.

Description

[Technical Field]

[0001] The present invention relates to wireless communication systems, and more particularly to a method of transmitting signals in a wireless communication system and an apparatus using the same. [Background technology]

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

[0003] NR improves efficiency and allows communication providers to offer more data and voice services over a given bandwidth. Therefore, the 3GPP (registered trademark) NR system is designed to meet the demand for high-speed data and media transmissions in addition to supporting large amounts of voice. The advantages of the NR system are higher throughput and lower latency on the same platform, support for frequency division duplex (FDD) and time division duplex (TDD), and low operating costs with an enhanced end-user environment and a simple architecture.

[0004] For more efficient data processing, the dynamic TDD of the NR system may use a method for changing the number of orthogonal frequency division multiplexing (OFDM) symbols that can be used in the uplink and downlink according to the data traffic direction of a cell user. For example, when the downlink traffic of a cell is larger than the uplink traffic, the base station may allocate more downlink OFDM symbols to a slot (or subframe). Information about the slot configuration should be transmitted to the terminal.

[0005] To mitigate the path loss of radio waves in the ultra-high frequency band and increase the transmission distance of radio waves, technologies being discussed for 5G communication systems include beamforming, massive multiple input / output (massive MIMO), full dimension multiple input / output (FD-MIMO), array antenna, analog beamforming, hybrid beamforming that combines analog beamforming and digital beamforming, and large scale antenna technologies. In addition, to improve the system network, technological developments are being carried out for the 5G communication system in areas such as 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, coordinated multi-points (CoMP), and interference cancellation.Other advanced coding modulation (ACM) methods being developed for 5G systems include hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC), as well as advanced access technologies such as filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA).

[0006] Meanwhile, in a human-centered connected network where humans generate and consume information, the Internet is evolving into the Internet of Things (IoT) network, which exchanges information among distributed components such as objects. Internet of Everything (IoE) technology is also emerging, combining IoT technology with big data processing technology through connections 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 considered for connecting objects. In an IoT environment, intelligent Internet technology (IT) services can be provided that collect and analyze data generated by 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 in areas such as smart homes, smart buildings, smart cities, smart or connected cars, smart grids, health management, smart home appliances, and advanced medical services.

[0007] 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 fusion of 5G technology and IoT technology. Generally, mobile communication systems are being developed to provide voice services while guaranteeing user activity.

[0008] However, mobile communication systems have gradually expanded beyond voice services to include data services, and have now been developed to the extent that they provide high-speed data services. However, due to the resource shortage phenomenon in currently available mobile communication systems and users' demand for high-speed services, more advanced mobile communication systems are needed. Summary of the Invention [Problem to be solved by the invention]

[0009] An object of the present invention is to provide a method for efficiently transmitting signals in a wireless communication system and an apparatus using the same. Specifically, an object of the present invention is to provide a method for determining a valid RO in a wireless communication system and an apparatus using the same. Another object of the present invention is to provide a method for transmitting and receiving signals based on a valid RO and an apparatus using the same. [Means for solving the problem]

[0010] According to one aspect of the present invention, there is provided a terminal for use in a wireless communication system, the terminal including: a communication module; and a processor for controlling the communication module, the processor receiving a cell-specific (or cell-common) radio resource control (RRC) signal regarding a slot format, the slot format including information regarding a symbol type, the symbol type including at least one of a downlink (DL) symbol, a flexible symbol, and an uplink (UL) symbol; and determining whether a physical random access channel (PRACH) occasion (RO) in a PRACH slot is valid, the determination being made based on whether the RO has been valid for at least N symbols since the last DL symbol. gap determining whether the RO is valid based on whether it starts after a symbol; and performing UL transmission or DL ​​reception based on whether the RO is valid; wherein a plurality of subbands are configured within one frequency band in at least one slot, the plurality of subbands including DL subbands and UL subbands, and when the RO is in the UL subband, the last DL symbol is determined based on a DL symbol configured by the cell-specific RRC signal, excluding a symbol in which the UL subband is configured.

[0011] In another aspect of the present invention, a method for use by a terminal in a wireless communication system includes the steps of receiving a cell-specific (or cell-common) radio resource control (RRC) signal related to a slot format, the slot format including information on a symbol type, the symbol type including at least one of a downlink (DL) symbol, a flexible symbol, and an uplink (UL) symbol; and determining whether a physical random access channel (PRACH) occasion (RO) in a PRACH slot is valid, the determination being made if the RO has occurred at least N times since the last DL symbol. gap and performing UL transmission or DL ​​reception based on whether the RO is valid, wherein a plurality of subbands are configured within one frequency band in at least one slot, the plurality of subbands including DL subbands and UL subbands, and when the RO exists in the UL subband, the last DL symbol is determined based on the DL symbol configured by the cell-specific RRC signal, excluding the symbol in which the UL subband is configured.

[0012] Preferably, the cell-specific RRC signaling may include common time division duplex (TDD) UL-DL configuration information.

[0013] Preferably, the determination is made based on whether the RO is in the UL subband, the RO does not precede in time a synchronization signal / physical broadcast channel (SS / PBCH) block in the PRACH slot, and the RO is at least N DL symbols from the last DL symbol. gap symbol and at least N symbols from the last SS / PBCH block received symbol gapThe method may include determining the RO to be valid if it starts after a symbol.

[0014] Preferably, the determining may include determining that the RO is valid if the RO is present on a UL symbol set configured by the cell-specific RRC signaling.

[0015] Preferably, N gap may be determined based on the SCS (subcarrier spacing) of the PRACH as follows: N gap = 0, and N if the SCS of the PRACH is 15 kHz, 30 kHz, 60 kHz, or 120 kHz. gap =2.

[0016] Preferably, the PRACH can be transmitted in the RO if the RO is valid.

[0017] Preferably, (a) the RO is present on the UL subband, (b) the RO is valid, and (c) a physical downlink shared channel (PDSCH) scheduled for the terminal is N in the time domain. gap If the PDSCH overlaps with at least one of the symbols and the RO, reception of the PDSCH may be determined based on whether the PDSCH is scheduled by downlink control information (DCI) or a higher layer (e.g., RRC), where the overlapping resources in the time domain may include at least one symbol.

[0018] Preferably, (a) the RO is present on the UL subband, (b) the RO is valid, and (c) a physical downlink shared channel (PDSCH) scheduled for the terminal is N in the time domain. gapand (d) if the PDSCH is scheduled by the DCI, the PDSCH may be received successfully and PRACH transmission may not be allowed in the RO.

[0019] Preferably, (a) the RO is present on the UL subband, (b) the RO is valid, and (c) a PDSCH scheduled for the terminal is N in the time domain. gap and (d) when the PDSCH is scheduled by the higher layer (e.g., RRC), the PDSCH may be received by performing rate matching based on the overlapping resources in the time domain, and PRACH transmission may be permitted in the RO. Here, the overlapping resources in the time domain may include at least one symbol. Also, the PDSCH scheduled by the higher layer may include a semi-static persistent scheduling (SPS) PDSCH. [Effects of the Invention]

[0020] The present invention provides a method for efficiently transmitting signals in a wireless communication system and an apparatus using the same. The present invention also provides a method for determining a valid RO in a wireless communication system and an apparatus using the same. Another object of the present invention is to provide a method for transmitting and receiving signals based on a valid RO and an apparatus using the same.

[0021] The effects obtained from the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those having ordinary skill in the art to which the present invention pertains from the following description. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 illustrates an example of a wireless frame structure used in a wireless communication system. [Figure 2]FIG. 1 illustrates an example of a downlink (DL) / uplink (UL) slot structure in a wireless communication system. [Figure 3] 1 is a diagram illustrating physical channels used in a 3GPP system and a typical signal transmission method using the physical channels. [Figure 4a] FIG. 1 illustrates an SS / PBCH block for initial cell access in a 3GPP NR system. [Figure 4b] FIG. 1 illustrates an SS / PBCH block for initial cell access in a 3GPP NR system. [Figure 5a] FIG. 1 illustrates a procedure for transmitting control information and control channels in a 3GPP NR system. [Figure 5b] FIG. 1 illustrates a procedure for transmitting control information and control channels in a 3GPP NR system. [Figure 6] FIG. 1 illustrates a control resource set (CORESET) in which a physical downlink control channel (PDCCH) may be transmitted in a 3GPP NR system. [Figure 7] FIG. 1 illustrates a method for configuring a PDCCH search space in a 3GPP NR system. [Figure 8] FIG. 1 is a conceptual diagram illustrating carrier aggregation. [Figure 9] FIG. 1 is a diagram for explaining single-carrier communication and multi-carrier communication. [Figure 10] A diagram showing an example in which a cross-carrier scheduling technique is applied. [Figure 11] 2A and 2B are block diagrams showing the configurations of a terminal and a base station according to an embodiment of the present invention. [Figure 12] FIG. 10 is a diagram illustrating a subband setting method. [Figure 13] FIG. 10 is a diagram illustrating a subband setting method. [Figure 14]FIG. 10 is a diagram illustrating RO (RACH occasion) within a slot. [Figure 15] 1 is a diagram illustrating a method for determining a valid RO according to an example of the present invention. [Figure 16] 1 is a diagram illustrating a method for determining a valid RO according to an example of the present invention. [Figure 17] 1 is a diagram illustrating a method for determining a valid RO according to an example of the present invention. [Figure 18] 1 is a diagram illustrating a method for determining a valid RO according to an example of the present invention. [Figure 19] 1 is a diagram illustrating a method for determining a valid RO according to an example of the present invention. [Figure 20] 1 is a diagram illustrating signal transmission and reception according to an example of the present invention; [Figure 21] 1 is a diagram illustrating signal transmission and reception according to an example of the present invention; [Figure 22] 1 is a diagram illustrating signal transmission and reception according to an example of the present invention; [Figure 23] 1 is a diagram illustrating signal transmission and reception according to an example of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0023] The terms used in this specification are currently widely used and general terms that are possible based on the functions of the present invention. However, the terms may be changed according to the intentions, practices, and the emergence of new technologies of those skilled in the art. In addition, in certain cases, there are terms arbitrarily selected by the applicant, and in this case, their meanings will be explained in the corresponding description of the present specification. Therefore, it is intended to be clear that the terms used in this specification should be analyzed based not only on the names of the terms but also on the substantial meaning of the terms and content throughout this specification.

[0024] Throughout this specification and the claims that follow, when an element is described as being "connected" to another element, the element may be "directly connected" to the other element or may be "electrically connected" to the other element through a third element. Furthermore, unless expressly stated to the contrary, the word "comprising" is understood to imply the inclusion of the stated elements and not the exclusion of any other elements unless otherwise specified. Moreover, limitations such as "equivalent to" or "equivalent to" based on a particular threshold value may be appropriately substituted with "greater than" or "less than," respectively, in some exemplary embodiments.

[0025] The following technologies may be used in various wireless access systems, such as 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 may be implemented by wireless technologies such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA may be implemented by wireless technologies such as Global System for Mobile Communications (GSM) / General Packet Radio Service (GPRS) / Enhanced Data Rates for GSM Evolution (EDGE). OFDMA may be implemented by wireless technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and Evolved UTRA (E-UTRA). UTRA is part of the Universal Mobile Telecommunications System (UMTS). Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) is part of Evolved UMTS (EUMTS) that uses Evolved UMTS Terrestrial Radio Access (E-UTRA), and LTE-Advanced (A) is an evolved version of 3GPP LTE. 3GPP New Radio (NR) is a system designed separately from LTE / LTE-A to support enhanced mobile broadband (eMBB), ultra-reliable and low latency communication (URLLC), and massive machine type communication (mMTC) services, which are requirements of IMT-2020. For clarity, 3GPP NR will be mainly described, but the technical idea of ​​the present invention is not limited thereto.

[0026] Unless otherwise specified herein, a base station may refer to a next-generation Node B (gNB) as defined in 3GPP NR. Furthermore, unless otherwise specified, a terminal may refer to a user equipment (UE). Hereinafter, for ease of understanding, each content will be described separately as an embodiment, but the embodiments may be used in combination with each other. In this disclosure, a configuration of a terminal may refer to a configuration by a base station. Specifically, a base station may transmit a channel or a signal to a terminal and configure parameter values ​​used in the operation of the terminal or the wireless communication system.

[0027] FIG. 1 illustrates an example of a wireless frame structure used in a wireless communication system.

[0028] Referring to FIG. 1, a wireless frame (or radio frame) used in a 3GPP NR system may have a length of 10 ms (ΔfmaxNf / 100)*Tc). In addition, the wireless frame includes 10 subframes (SFs) of equal size. In this specification, Δfmax=480*103 Hz, Nf=4096, Tc=1 / (Δfref*Nf,ref), Δfref=15*103 Hz, and Nf,ref=2048. The 10 subframes in one wireless frame may be assigned numbers from 0 to 9. Each subframe may have a length of 1 ms and may include one or more slots according to the subcarrier spacing. More specifically, in a 3GPP NR system, the subcarrier spacing that may be used is 15*2 μkHz, and μ may have a value of μ=0 to 4 as the subcarrier spacing configuration. That is, subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 240 kHz may be used. A subframe having a length of 1 ms may include 2 μ slots. In this case, the length of each slot is 2 μms. The 2 μ slots in a subframe may be assigned numbers from 0 to 2 μ−1. Additionally, the slots in a wireless frame may be assigned numbers from 0 to 10*2 μ−1. Time resources may be distinguished by at least one of a wireless frame number (also referred to as a wireless frame index), a subframe number (also referred to as a subframe index), and a slot number (or a slot index).

[0029] 2 illustrates an example of a downlink (DL) / uplink (UL) slot structure in a wireless communication system. In particular, FIG. 2 illustrates a resource grid structure for a 3GPP NR system.

[0030] Specifically, Figure 2 shows the structure of a resource grid in a 3GPP NR system. There is one resource grid per antenna port. Referring to Figure 2, a slot includes multiple Orthogonal Frequency Division Multiplexing (OFDM) symbols in the time domain and multiple Resource Blocks (RBs) in the frequency domain. An OFDM symbol also refers to one symbol section. Unless otherwise specified, an OFDM symbol may simply be referred to as a symbol. One RB includes 12 consecutive subcarriers in the frequency domain. Referring to Figure 2, the signal transmitted from each slot is divided into N size,μ grid,x *N RB sc Book subcarrier and N slot symb may be represented by a resource grid containing N OFDM symbols, where x=DL if the signal is a DL signal and x=UL if the signal is a UL signal. size,μ grid,x represents the number of resource blocks (RBs) according to the subcarrier spacing, which is a component of μ (x is DL or UL), and N slot symb represents the number of OFDM symbols in a slot. RB sc is the number of subcarriers that make up one RB, and N RB sc = 12. Depending on the multiple access scheme, OFDM symbols may be called cyclic shift OFDM (CP-OFDM) symbols or discrete Fourier transform spread OFDM (DFT-s-OFDM) symbols.

[0031] The number of OFDM symbols included in one slot may vary according to the length of the cyclic prefix (CP). For example, in the case of a normal CP, one slot may include 14 OFDM symbols, while in the case of an extended CP, one slot may include 12 OFDM symbols. In a particular embodiment, the extended CP may be used only with 60 kHz subcarrier spacing. In FIG. 2, for convenience of explanation, one slot is configured using 14 OFDM symbols as an example, but the embodiments of the present disclosure may be similarly applied to slots having a different number of OFDM symbols. Referring to FIG. 2, each OFDM symbol is N size,μ grid,x *N RB sc The carrier frequency includes four subcarriers. The subcarrier types can be divided into data subcarriers for data transmission, reference signal subcarriers for transmitting reference signals, and guard bands. The carrier frequency is also called the center frequency (fc).

[0032] One RB is N RB sc A resource may be defined by (e.g., 12) consecutive subcarriers. For reference, a resource configured using one OFDM symbol and one subcarrier may be referred to as a resource element (RE) or tone. Thus, one RB may be defined by N slot symb *N RB sc Each resource element in the resource grid can be uniquely defined within one slot by a pair of indices (k, l), where k ranges from 0 to N in the frequency domain. size,μ grid,x *N RB sc l may be an index ranging from 0 to N in the time domain. slot symb It may be an index numbered down to -1.

[0033] In order for a UE to receive signals from or transmit signals to a base station, the time / frequency of the UE may be synchronized to the time / frequency of the base station because when the base station and the UE are synchronized, the UE can determine the time and frequency parameters needed to demodulate DL signals and transmit UL signals at the appropriate times.

[0034] Each symbol of a radio frame used in time division duplex (TDD), i.e., unpaired spectrum, may be configured with at least one of DL symbols, UL symbols, and flexible symbols. In frequency division duplex (FDD), i.e., paired spectrum, a radio frame used as a DL carrier may be configured with DL symbols or flexible symbols, and a radio frame used as a UL carrier may be configured with UL symbols or flexible symbols. DL symbols allow DL transmission but not UL transmission. UL symbols allow UL transmission but not DL transmission. Flexible symbols may be determined to be used as DL or UL according to the signal.

[0035] Information about each symbol type, i.e., information indicating any one of DL symbols, UL symbols, and flexible symbols, can be configured using cell-specific or common radio resource control (RRC) signals. In addition, information about each symbol type can be additionally configured using UE-specific or dedicated RRC signals. The base station notifies 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 the 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 the slot with only UL symbols by using cell-specific RRC signals. Here, a symbol that is not configured using either UL symbols or DL ​​symbols is a flexible symbol.

[0036] When the information about the symbol type is configured using the UE-specific RRC signal, the base station may signal in the cell-specific RRC signal whether the flexible symbol is a DL symbol or an UL symbol. In this case, the UE-specific RRC signal cannot change the DL symbol or the UL symbol configured using the cell-specific RRC signal to another symbol type. The UE-specific RRC signal may signal the N of the corresponding slots per slot. slot symb The number of DL symbols among the symbols and the N of the corresponding slot 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. Additionally, 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 UL symbols or DL symbols is a flexible symbol.

[0037] FIG. 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.

[0038] When the power of the UE is turned on or the UE camps on a new cell, the UE performs initial cell search (S101). Specifically, the UE can synchronize with the BS during initial cell search. For this purpose, the UE can receive a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) from the base station to synchronize with the base station and obtain information such as the cell ID. Thereafter, the UE can receive a physical broadcast channel from the base station and obtain broadcast information in the cell.

[0039] Upon completion of the initial cell search, the UE receives a physical downlink shared channel (PDSCH) according to the physical downlink control channel (PDCCH) and the information in the PDCCH. As a result, the UE can obtain system information more specific than the system information obtained through the initial cell search (S102). Here, the system information obtained by the UE is cell-common system information for the UE to operate correctly at the physical layer in Radio Resource Control (RRC), and is also called remaining system information or system information block (SIB) 1.

[0040] When a terminal first accesses a base station or when there are no radio resources for signal transmission (if the terminal is in RRC_IDLE mode), the terminal performs a random access procedure with the base station (S103 to S106). First, the terminal transmits a preamble over a physical random access channel (PRACH) (S103) and receives a random access response (RAR) message for the preamble from the base station over a PDCCH and a corresponding PDSCH (S104). If the terminal receives a valid random access response, the terminal transmits data including its own identifier to the base station over a physical uplink shared channel (PUSCH) indicated in the uplink grant transmitted from the base station over the PDCCH or PDSCH (S105). Next, the terminal waits for reception of a PDCCH as instructed by the base station to resolve collisions. If the terminal successfully receives the PDCCH via its identifier and the corresponding PDSCH (S106), the random access procedure is terminated. During the random access procedure, the terminal acquires a terminal-identification system in the RRC layer, which is necessary for the terminal to operate properly in the physical layer. When the terminal acquires terminal-specific system information from the RRC layer, the terminal enters the RRC connected mode (RRC_CONNECTED mode).

[0041] The RRC layer is used to generate and manage messages for control between a terminal and a wireless access network (RAN). More specifically, the base station and terminal can perform storage management including broadcasting cell system information required for all terminals in a cell, transmission management of paging messages, mobility management and handover, terminal measurement reports and control thereof, terminal capability management, and device management at the RRC layer. Generally, the update of signals transmitted at the RRC layer (hereinafter referred to as RRC signals) is longer than the transmission / reception period (i.e., transmission time interval, TTI) at the physical layer, so that RRC signals can be maintained unchanged for a long period.

[0042] After the above-described procedure, 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 vary depending on the intended use. The uplink control information (UCI) transmitted by the UE to the base station through the UL includes a DL / UL ACK / NACK signal, 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 channel state information (CSI). In a 3GPP NR system, a UE may transmit control information, such as the HARQ-ACK and CSI described above, over the PUSCH and / or PUCCH.

[0043] 4a and 4b show SS / PBCH blocks for initial cell access in a 3GPP NR system.

[0044] When powered on or wanting to access a new cell, the UE may acquire time and frequency synchronization with the cell and perform an initial cell search procedure. The UE may acquire the physical cell identity N of the cell during the cell search procedure. cell IDTo this end, the UE may receive synchronization signals, such as a primary synchronization signal (PSS) and a secondary synchronization signal (SSS), from the base station and synchronize to the base station. In this case, the UE may obtain information such as a cell identity (ID).

[0045] Referring to FIG. 4a, the synchronization signal (SS) will be described in more detail. The synchronization signal can be classified into a PSS and an SSS. The PSS can be used to obtain time-domain and / or frequency-domain synchronization, such as OFDM symbol synchronization and slot synchronization. The SSS can be used to obtain frame synchronization and a cell group ID. Referring to FIG. 4a and Table 1, an SS / PBCH block can be configured using 20 consecutive RBs (=240 subcarriers) in the frequency domain and 4 consecutive OFDM symbols in the time domain. 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 of the SS / PBCH block is numbered starting from 0. In the first OFDM symbol in which the PSS is transmitted, the base station does not transmit signals through the remaining subcarriers, i.e., subcarriers 0 to 55 and 183 to 239. In addition, in the third OFDM symbol in which the SSS is transmitted, the base station does not transmit signals through subcarriers 48 to 55 and 183 to 191. The base station transmits a physical broadcast channel (PBCH) through the remaining REs in the SS / PBCH block excluding the above signals.

[0046] [Table 1]

[0047] The SS allows a total of 1008 unique physical layer cell IDs to be grouped into 336 physical layer cell identifier groups, each group specifically including three unique identifiers through the combination of three PSSs and SSSs such that each physical layer cell ID is only part of one physical layer cell identifier group. Thus, the physical layer cell IDs N cell ID =3N (1) ID +N (2) ID is 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 a physical layer identifier within the physical layer cell identifier group. (2) ID The UE may detect the PSS and identify one of three unique physical layer identifiers. In addition, the UE may detect the SSS and identify one of 336 physical layer cell IDs associated with the physical layer identifier. In this case, the sequence d of the PSS PSS (n) is as follows:

[0048]

number

[0049] where:

number

[0050]

number

[0051] Furthermore, the SSS series d SSS (n) is as follows:

[0052]

number

[0053] where:

number

[0054]

number

[0055] A 10-ms radio frame may be divided into two 5-ms half-frames. Referring to Figure 4b, the slots in which the SS / PBCH blocks are transmitted within each half-frame are described. The slots in which the SS / PBCH blocks are 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 for carrier frequencies below 3 GHz. Additionally, n = 0, 1, 2, or 3 may be used for 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 for carrier frequencies below 3 GHz. Additionally, n = 0 or 1 may be used for carrier frequencies above 3 GHz and below 6 GHz. In Case 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 for carrier frequencies below 3 GHz. Additionally, n=0, 1, 2, or 3 for carrier frequencies above 3 GHz and below 6 GHz. In Case 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=0, 1, 2, 3, 5, 6, 7, 8, 10, 11, 12, 13, 15, 16, 17, or 18 for carrier frequencies above 6 GHz. In Case 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, n=0, 1, 2, 3, 5, 6, 7, 8 for carrier frequencies above 6 GHz.

[0056] 5A and 5B show a procedure for transmitting control information and control channels in a 3GPP NR system. Referring to FIG. 5A, a base station may add a cyclic redundancy check (CRC) masked (e.g., XORed) with a radio network temporary identifier (RNTI) to 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 control information. The common RNTI used by one or more UEs may include at least one of a system information RNTI (SI-RNTI), a paging RNTI (P-RNTI), a random access RNTI (RA-RNTI), and a transmit power control RNTI (TPC-RNTI). In addition, a UE-specific RNTI may include at least one of a cell temporary RNTI (C-RNTI) and a CS-RNTI. The base station may then 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 DCI based on a control channel element (CCE)-based PDCCH structure (S208). Additionally, 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 resources to be transmitted. A CCE is a basic resource unit for the PDCCH, and one CCE may include multiple (e.g., 6) resource element groups (REGs). One REG may be configured with multiple (e.g., 12) REs. The number of CCEs used for one PDCCH may be defined as an aggregation level.In a 3GPP NR system, aggregation levels of 1, 2, 4, 8, or 16 may be used. Figure 5B is a diagram relating to CCE aggregation levels and PDCCH multiplexing, showing the types of CCE aggregation levels used for one PDCCH and the CCEs transmitted in the control area accordingly.

[0057] FIG. 6 illustrates a control resource set (core set) in which a physical downlink control channel (PDCCH) may be transmitted in a 3GPP NR system.

[0058] A core set is a time-frequency resource within which the PDCCH, i.e., a control signal for the UE, is transmitted. In addition, a search space, which will be described later, may be mapped to a core set. Thus, rather than monitoring all frequency bands for PDCCH reception, the UE may monitor a time-frequency region designated as a core set and decode the PDCCH mapped to the core set. A base station may configure one or more core sets for a UE per cell. A core set may be configured using up to three consecutive symbols on the time axis. Additionally, a core set may be configured in units of six consecutive PRBs on the frequency axis. In the embodiment of FIG. 6, core set #1 is configured using consecutive PRBs, and core sets #2 and #3 are configured using non-consecutive PRBs. A core set may be positioned within any symbol within a slot. For example, in the embodiment of FIG. 6, core set #1 starts in the first symbol of the slot, core set #2 starts in the fifth symbol of the slot, and core set #9 starts in the ninth symbol of the slot.

[0059] FIG. 7 illustrates a method for configuring a PUCCH search space in a 3GPP NR system.

[0060] To transmit a PDCCH to a UE, each core set may have at least one search space. In an embodiment of the present disclosure, a search space is a set of all time-frequency resources (hereinafter referred to as PDCCH candidates) through which the UE's PDCCH can be transmitted. The search space may include a common search space that 3GPP NR UEs are required to search in common, and a terminal-specific or UE-specific search space that a specific UE is required to search. In the common search space, a UE may monitor a PDCCH that all UEs in a cell belonging to the same base station are configured to search in common. In addition, a UE-specific search space may be configured for each UE so that the UE monitors the PDCCH allocated to each UE at different search space positions according to the UE. In the case of a UE-specific search space, the search spaces between UEs may be partially overlapped due to the limited control areas in which the PDCCHs are allocated. Monitoring the PDCCH includes blind decoding to find PDCCH candidates within the search space. When blind decoding is successful, it may be expressed that the PDCCH is (successfully) detected / received, and when blind decoding fails, it may be expressed that the PDCCH is not detected / received or is not successfully detected / received.

[0061] For ease of description, a PDCCH scrambled with a group common (GC) RNTI previously known to one or more UEs to transmit DL control information to one or more UEs is referred to as a group common (GC) PDCCH or a common PDCCH. In addition, a PDCCH scrambled with a terminal-specific RNTI already known by a specific UE to transmit UL or DL ​​scheduling information to that UE is referred to as a UE-specific PDCCH. A common PDCCH may be included in a common search space, and a UE-specific PDCCH may be included in a common search space or a UE-specific PDCCH.

[0062] A base station may signal information related to resource allocation of the transmission channels paging channel (PCH) and downlink shared channel (DL-SCH) (i.e., DL grants) or information related to resource allocation of the uplink shared channel (UL-SCH) and hybrid automatic repeat request (HARQ) (i.e., UL grants) to each UE or a group of UEs via the PDCCH. The base station may transmit PCH transport blocks and DL-SCH transport blocks via the PDSCH. The base station may transmit data excluding specific control information or specific service data via the PDSCH. In addition, a UE may receive data excluding specific control information or specific service data via the PDSCH.

[0063] A base station may transmit a PDCCH to a UE (one or more UEs) including information about where PDSCH data is to be transmitted and how the PDSCH data will be received and decoded by the corresponding UE. For example, assume that the DCI transmitted on a specific PDCCH is CRC masked using an RNTI of "A," and the DCI indicates that the PDSCH is allocated to a radio resource (e.g., a frequency location) of "B," and indicates transmission format information (e.g., transport block size, modulation scheme, coding information, etc.) of "C." The UE monitors the PDCCH using the RNTI information that the UE has. In this case, if a UE performs blind decoding of the PDCCH using the RNTI of "A," the UE receives the PDCCH and, through the received PDCCH information, receives the PDSCH indicated by "B" and "C."

[0064] Table 2 illustrates one embodiment of a physical uplink control channel (PUCCH) used in a wireless communication system.

[0065] [Table 2]

[0066] The PUCCH may be used to transmit the following UL control information (UCI):

[0067] - Scheduling Request (SR): Information used to request UL UL-SCH resources.

[0068] - HARQ-ACK: A response to the PDCCH (indicating DL SPS release) and / or a response to a DL transport block (TB) on the PDSCH. The HARQ-ACK indicates whether information transmitted on the PDCCH or PDSCH has been received. HARQ-ACK responses include a positive ACK (simply ACK), a negative ACK (hereinafter NACK), discontinuous transmission (DTX), or NACK / DTX. Here, the term HARQ-ACK is used interchangeably with HARQ-ACK / NACK and ACK / NACK. In general, an ACK may be represented by a bit value of 1, and a NACK may be represented by a bit value of 0.

[0069] Channel State Information (CSI): Feedback information on the DL channel. The UE generates it based on the CSI reference signal (RS) transmitted by the base station. Multiple-input multiple-output (MIMO)-related feedback information includes a rank indicator (RI) and a precoding matrix indicator (PMI). The CSI may be divided into CSI part 1 and CSI part 2 according to the information indicated by the CSI.

[0070] In a 3GPP NR system, five PUCCH formats may be used to support different service scenarios, different channel environments, and frame structures.

[0071] 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 over one or two OFDM symbols on the time axis and one RB on the frequency axis. When PUCCH format 0 is transmitted in two OFDM symbols, the same sequence on the two symbols may be transmitted over different RBs. In this case, the sequence may be a cyclic shift (CS) sequence of a base sequence used for PUCCH format 0. This allows the UE to obtain frequency diversity gain. Specifically, the terminal bit Bit UCI(M bit =1 or 2) to determine the cyclic shift (CS) value m cs Also, the length 12 basic sequence can be determined by the given CS value m cs Based on this, the cyclically shifted sequence can be mapped to 12 REs of one OFDM symbol and one RB and transmitted. bit = 1, one bit UCI 0 and 1 can be mapped to two cyclic shifted sequences, respectively, with a difference in cyclic shift value of 6. bit = 2, the 2-bit UCI 00, 01, 11, 10 can be mapped to four cyclic shifted sequences with a cyclic shift value difference of 3, respectively.

[0072] PUCCH format 1 carries 1-bit or 2-bit HARQ-ACK information or SR. PUCCH format 1 is transmitted using consecutive OFDM symbols on the time axis and one PRB on the frequency axis. Here, the number of OFDM symbols occupied by PUCCH format 1 is one of 4 to 14. More specifically, bit The UCI with M = 1 is modulated by BPSK. bitThe UCI, where d(0) = 2, is modulated using quadrature phase shift keying (QPSK). The modulated complex-valued symbol d(0) is multiplied by a sequence of length 12 to obtain a signal. The terminal spreads the obtained signal using a time-domain orthogonal cover code (OCC) on even-numbered OFDM symbols assigned to PUCCH format 1 and transmits it. In PUCCH format 1, the maximum number of different terminals that can be multiplexed in the same RB is determined according to the length of the OCC used. In odd-numbered OFDM symbols of PUCCH format 1, a demodulation reference signal (DMRS) is spread using OCC and mapped.

[0073] PUCCH format 2 can deliver UCI exceeding two bits. PUCCH format 2 can be transmitted over one or two OFDM symbols on the time axis and one or more RBs on the frequency axis. When PUCCH format 2 is transmitted in two OFDM symbols, the sequences transmitted in different RBs over the two OFDM symbols may be identical to each other. Here, the sequence is a sequence of modulated complex-valued symbols d(0),...,d(M symbol -1), where M symbol is M bit / 2. Through this, the UE may obtain frequency diversity gain. More specifically, M bit Bit UCI(M bit >2) is bit-level scrambled, QPSK modulated, and mapped to RBs of one or two OFDM symbols, where the number of RBs may be one of 1 to 16.

[0074] PUCCH format 3 or PUCCH format 4 may deliver UCI exceeding 2 bits. PUCCH format 3 or PUCCH format 4 may be transmitted over consecutive 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 may transmit M-ary PUCCH using π / 2-2 phase shift keying (BPSK) or QPSK. bit The complex-valued symbols d(0) to d(M symb -1) where, when π / 2-BPSK is used, M symb =M bit and when using QPSK, M symb =M bit / 2. The UE does not need to apply block-wise spreading to PUCCH format 3. However, the UE may apply block-wise spreading to one RB (i.e., 12 subcarriers) using 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, maps it to each RE, and transmits the spread signal.

[0075] 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 over the PUCCH. When 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.

[0076] PUCCH Format 1, PUCCH Format 3, or PUCCH Format 4 may be configured through RRC signaling 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 RRC signaling. When PUCCH Format 1, PUCCH Format 3, or PUCCH Format 4 is transmitted over 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.

[0077] PUCCH Format 1, PUCCH Format 3, or PUCCH Format 4 may be configured to be repeatedly transmitted in multiple slots. In this case, the number K of slots in which the PUCCH is repeatedly transmitted may be configured by RRC signaling. The repeatedly transmitted PUCCH must start at a fixed OFDM symbol in each slot and must have a constant length. When one of the OFDM symbols of a slot in which the UE should transmit the PUCCH is indicated as a DL symbol by RRC signaling, the UE may not transmit the PUCCH in the corresponding slot and may delay transmission of the PUCCH until the next slot for transmitting the PUCCH.

[0078] Meanwhile, in a 3GPP NR system, a terminal can transmit and receive using a bandwidth smaller than or equal to the bandwidth of a carrier (or cell). To this end, the terminal may be configured with a bandwidth part (BWP) consisting of a contiguous portion of the carrier's bandwidth. A terminal operating according to TDD or using an unpaired spectrum may be configured with up to four DL / UL BWP pairs per carrier (or cell). The terminal can also activate one DL / UL BWP pair. A terminal operating according to FDD or using a paired spectrum may be configured with up to four DL BWPs per downlink carrier (or cell) and up to four UL BWPs per uplink carrier (or cell). The terminal can activate one DL BWP and one UL BWP for each carrier (or cell). The terminal does not need to receive or transmit on time-frequency resources other than the activated BWPs. An activated BWP can be referred to as an active BWP.

[0079] A base station can indicate to a terminal which BWPs among configured BWPs are activated using downlink control information (DCI). The BWP indicated in the DCI is activated, and other configured BWPs are deactivated. In a carrier (or cell) operating in TDD, the base station can include a bandwidth part indicator (BPI) indicating the activated BWP in the DCI scheduling a PDSCH or a PUSCH to change the DL / UL BWP pair of the terminal. The terminal can receive the DCI scheduling a PDSCH or a PUSCH and identify the activated DL / UL BWP pair based on the BPI. In a downlink carrier (or cell) operating in FDD, the base station can include a BPI indicating the activated BWP in the DCI scheduling a PDSCH to change the DL BWP of the terminal. In an uplink carrier (or cell) operating in FDD, the base station can include a BPI indicating the activated BWP in the DCI scheduling a PDSCH to change the UL BWP of the terminal.

[0080] FIG. 8 is a conceptual diagram illustrating carrier aggregation.

[0081] In this method, a UE uses multiple frequency blocks or cells (in a logical sense) configured using UL resources (or component carriers) and / or DL ​​resources (or component carriers) as one large logical frequency band to achieve this. One component carrier may also be referred to as a primary cell (PCell) or a secondary cell (SCell), or a primary SCell (PScell). However, hereinafter, the term "component carrier" will be used for convenience of explanation.

[0082] Referring to Figure 8, as an example of a 3GPP NR system, the overall system band may include up to 16 component carriers, and each component carrier may have a bandwidth of up to 400 MHz. A component carrier may include one or more physically contiguous subcarriers. Although Figure 8 shows each of the component carriers having the same bandwidth, this is merely an example, and each component carrier may have a different bandwidth. Also, although the component carriers are shown as being adjacent to each other on the frequency axis, the drawing is shown in a logical concept, and the component carriers may be physically adjacent to each other or spaced apart.

[0083] A different center frequency may be used for each component carrier. Also, one common center frequency may be used for physically adjacent component carriers. In the embodiment of Figure 8, assuming that all component carriers are physically adjacent, center frequency A may be used for all component carriers. Furthermore, assuming that the respective component carriers are not physically adjacent to each other, center frequency A and center frequency B may be used for each of the component carriers.

[0084] When the overall system band is expanded by carrier aggregation, the frequency band used for communication with each UE may be specified in component carrier units. UE A may use the overall system band of 100 MHz and perform communication using all five component carriers. UEs B1 to B5 may use only a 20 MHz bandwidth and perform communication using one component carrier. UEs C1 and C2 may use a 40 MHz bandwidth and each perform communication using two component carriers. The example in FIG. 8 shows a case where UE C1 uses two non-adjacent component carriers and UE C2 uses two adjacent component carriers.

[0085] 9A and 9B are diagrams for explaining single-carrier communication and multi-carrier communication. Specifically, FIG. 9A shows a single-carrier subframe structure, and FIG. 9B shows a multi-carrier subframe structure.

[0086] Referring to FIG. 9(a), in FDD mode, a typical wireless communication system may transmit or receive data through one DL band and one UL band corresponding thereto. In another specific embodiment, in TDD mode, the wireless communication system may divide a radio frame into UL time units and DL time units in the time domain and transmit or receive data through the UL / DL time units. Referring to FIG. 9(b), three 20 MHz component carriers (CCs) may be aggregated into UL and DL so that a 60 MHz bandwidth can be supported. The CCs may or may not be adjacent to each other in the frequency domain. Although FIG. 9(b) illustrates a case where the bandwidth of the UL CC and the bandwidth of the DL CC are identical and symmetrical, the bandwidth of each CC may be determined independently. In addition, asymmetric carrier aggregation, in which the number of UL CCs and DL CCs differs, is possible. The DL / UL CC allocated / configured to a specific UE through RRC may be referred to as the serving DL / UL CC of the specific UE.

[0087] A base station may communicate with a UE by activating some or all of the UE's serving CCs or deactivating some CCs. The base station can change the CCs to be activated / deactivated and the number of CCs to be activated / deactivated. When a 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 for the UE is completely reconfigured or the UE is handed over. A CC that is not deactivated by the UE is called a Primary CC (PCC) or a Primary Cell (PCell), and a CC that the base station can activate / deactivate freely is called a Secondary CC (SCC) or a Secondary Cell (SCell).

[0088] 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 can be configured with only DL resources or a combination of DL resources and UL resources. When carrier aggregation is supported, the association between the carrier frequency of DL resources (i.e., DL CC) and the carrier frequency of UL resources (i.e., UL CC) may be indicated by system information. 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 an SCell. A carrier corresponding to a PCell in the DL is a DL PCC, and a carrier corresponding to a PCell in the UL is a UL PCC. Similarly, a carrier corresponding to an SCell in the DL is a DL SCC, and a carrier corresponding to an SCell in the UL is a UL SCC. According to UE capabilities, a serving cell can be configured with one PCell and zero or more SCells. For a UE that is in RRC_CONNECTED state but is not configured for or does not support carrier aggregation, there is only one serving cell configured with only a PCell.

[0089] As mentioned above, the term "cell" used in carrier aggregation is distinguished from the term "cell" which refers to several geographical areas for which communication services are provided by one base station or one antenna group. That is, one component carrier may also be referred to as a scheduling cell, scheduled cell, primary cell (PCell), secondary cell (SCell), or primary SCell (PScell). However, to distinguish between cells which refer to several geographical areas and cells of carrier aggregation, in this disclosure, cells of carrier aggregation are referred to as CCs, and cells of geographical areas are referred to as cells.

[0090] 10 illustrates an example in which a cross-carrier scheduling technique is applied. When cross-carrier scheduling is configured, a control channel transmitted over a first CC may schedule a data channel transmitted over the first CC or a second CC using a carrier indicator field (CIF). The CIF is included in the DCI. In other words, a scheduling cell is configured, and a DL grant / UL grant transmitted in the PDCCH area of ​​the scheduling cell schedules the PDSCH / PUSCH of the scheduled cell. That is, a search area for multiple component carriers exists in the PDCCH area of ​​the scheduling cell. A PCell may essentially be the scheduling cell, and a specific SCell may be designated as the scheduling cell by higher layers.

[0091] In the embodiment of FIG. 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 carrier #1 and DL component carrier #2 are DL SCCs (or SCells). In addition, it is assumed that the DL PCC is configured as a PDCCH monitoring CC. When cross-carrier scheduling is not configured by UE-specific (or UE group-specific or cell-specific) higher layer signaling, the CIF is disabled, and each DL CC can transmit only a PDCCH for scheduling its PDSCH without using a CIF according to the NR PDCCH rules (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) higher layer signaling, the CIF is enabled, and a specific CC (e.g., a DL PCC) may transmit not only a PDCCH for scheduling a PDSCH of DL CC A using the CIF, but also a PDCCH for scheduling a PDSCH of another CC (cross-carrier scheduling). On the other hand, the PDCCH is not transmitted in another DL CC. Thus, the UE monitors either the PDCCH without a CIF to receive a self-carrier scheduled PDSCH or the PDCCH with a CIF to receive a cross-carrier scheduled PDSCH, depending on whether cross-carrier scheduling is configured for the UE.

[0092] 9 and 10 show the subframe structure of a 3GPP LTE-A system, and the same or similar configurations may be applied to a 3GPP NR system, except that in a 3GPP NR system, the subframes in FIGS. 9 and 10 may be replaced with slots.

[0093] FIG. 11 is a block diagram illustrating the configuration of a terminal and a base station according to an embodiment of the present disclosure.

[0094] In the embodiments of the present disclosure, the terminal may be embodied as various wireless communication devices or computer devices that ensure portability and mobility. The terminal may also be referred to as User Equipment (UE), Station (STA), Mobile Subscriber (MS), etc. In addition, in the embodiments of the present disclosure, the base station controls and manages cells (e.g., macrocells, femtocells, picocells, etc.) corresponding to a service area, and may have functions such as signal transmission, channel assignment, channel monitoring, self-diagnosis, and relaying. The base station may also be referred to as a next generation Node B (gNB) or Access Point (AP), etc.

[0095] As shown, 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 .

[0096] First, the processor 110 can execute various instructions or programs to process data within the terminal 100. The processor 110 can also control the overall operation of the terminal 100, including each unit, and control data transmission and reception between the units. Here, the processor 110 may be configured to perform operations according to the embodiments described in this disclosure. For example, the processor 110 can receive slot configuration information, determine a slot configuration based on the received information, and perform communication according to the determined slot configuration.

[0097] 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. To this end, the communication module 120 may include multiple network interface cards (NICs) such as cellular communication interface cards 121 and 122 and an unlicensed band communication interface card 123, either built-in or external. Although the communication module 120 is shown as an integrated module in the figure, each network interface card may be independently arranged depending on the circuit configuration or application, unlike the drawing.

[0098] The cellular communication interface card 121 can transmit and receive wireless signals to and from at least one of the base station 200, an external device, and a server using a mobile communication network, and can 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 can include at least one NIC module using a frequency band below 6 GHz. The at least one NIC module of the cellular communication interface card 121 can independently perform cellular communication with at least one of the base station 200, an external device, and a server in accordance with a cellular communication standard or protocol for the frequency band below 6 GHz supported by the NIC module.

[0099] The cellular communication interface card 122 transmits and receives wireless signals to and from at least one of the base station 200, the external device, and the server using a mobile communication network, and can provide cellular communication services using the second frequency band based on instructions from the processor 110. According to one embodiment, the cellular communication interface card 122 can include at least one NIC module using a frequency band above 6 GHz. The 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, the external device, and the server in accordance with a cellular communication standard or protocol for the frequency band above 6 GHz supported by the NIC module.

[0100] The unlicensed band communication interface card 123 transmits and receives wireless signals to and from at least one of the base station 200, an external device, and a server using a third frequency band, which is an unlicensed band, and provides unlicensed band communication services based on instructions from the processor 110. The unlicensed band communication interface card 123 may include at least one NIC module using an unlicensed band. For example, the unlicensed band may be 2.4 GHz, 5 GHz, 6 GHz, 7 GHz, or the 5 GHz band, which is equal to or greater than 52.6 GHz. The at least one NIC module of the unlicensed band communication interface card 123 may independently or dependently communicate with at least one of the base station 200, an external device, and a server in accordance with the unlicensed band communication standard or protocol of the frequency band supported by the NIC module.

[0101] Next, the memory 130 stores control programs and various data used by the terminal 100. Such control programs may include predetermined programs required for the terminal 100 to perform wireless communication with at least one of the base station 200, an external device, and a server.

[0102] 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. Also, the user interface 140 can perform output based on instructions from the processor 110 using various output means.

[0103] The display unit 150 then outputs various images to a display screen, and can output various display objects, such as content executed by the processor 110 or a user interface based on control instructions of the processor 110.

[0104] Furthermore, the base station 200 according to an embodiment of the present disclosure may include a processor 210, a communication module 220, and a memory 230.

[0105] First, the processor 210 can execute various instructions or programs to process data within the base station 200. The processor 210 can also control the overall operation of each unit of the base station 200 and control data transmission and reception between the units. Here, the processor 210 may be configured to perform operations according to the embodiments described in this disclosure. For example, the processor 210 can signal slot configuration information and perform communication according to the signaled slot configuration.

[0106] 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. To this end, the communication module 220 may include multiple network interface cards, such as cellular communication interface cards 221 and 222 and an unlicensed band communication interface card 223, in an internal or external form. Although the communication module 220 is shown as an integrated module in the figure, each network interface card may be independently arranged depending on the circuit configuration or application, unlike the drawing.

[0107] The cellular communication interface card 221 can transmit and receive wireless signals to and from at least one of the terminal 100, the external device, and the server using a mobile communication network, and can provide cellular communication services using the first frequency band based on instructions from the processor 210. According to one embodiment, the cellular communication interface card 221 can include at least one NIC module using a frequency band below 6 GHz. The 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, the external device, and the server in accordance with a cellular communication standard or protocol for the frequency band below 6 GHz supported by the NIC module.

[0108] 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 using the second frequency band based on instructions from the processor 210. According to one embodiment, the cellular communication interface card 222 can include at least one NIC module using a frequency band above 6 GHz. The 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 for the frequency band above 6 GHz supported by the NIC module.

[0109] The unlicensed band communication interface card 223 transmits and receives wireless signals to and from at least one of the terminal 100, an external device, and a server using a third frequency band, which is an unlicensed band, and provides unlicensed band communication services based on instructions from the processor 210. The unlicensed band communication interface card 223 may include at least one NIC module using an unlicensed band. For example, the unlicensed band may be 2.4 GHz, 5 GHz, 6 GHz, 7 GHz, or the 5 GHz band, which is equal to or greater than 52.6 GHz. The at least one NIC module of the unlicensed band communication interface card 223 may perform wireless communication with at least one of the terminal 100, an external device, and a server, independently or dependently, in accordance with the unlicensed band communication standard or protocol of the frequency band supported by the NIC module.

[0110] The terminal 100 and base station 200 shown in FIG. 11 are block diagrams according to an embodiment of the present invention, and the separated blocks indicate logically distinct device elements. Therefore, the above-described device elements may be implemented as a single chip or multiple chips depending on the device design. Also, 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. Also, the user interface 140 and the display unit 150 may be further provided in the base station 200 as necessary.

[0111] A slot format may be configured to a terminal in a TDD or unpaired spectrum system by a base station. The slot format may refer to a type of symbol in a slot. The symbol type may be at least one of a downlink symbol (DL symbol), an uplink symbol (UL symbol), or a flexible symbol. The symbol type for a slot in a radio frame may be configured to a terminal by a base station. A flexible symbol may refer to a symbol that is not configured as a downlink symbol or an uplink symbol.

[0112] The terminal may receive information about each symbol type in a slot from the base station using a cell-specific or cell-common radio resource control (RRC) signal. Alternatively, the terminal may receive information about each symbol type in a slot semi-statically in SIB1. The terminal may also receive information about each symbol type in a slot semi-statically from the base station using a UE-specific or UE-dedicated RRC signal. The base station may configure / set each symbol type in a slot for the terminal using the information about each symbol type in a slot.

[0113] When the terminal receives information about each symbol type in a slot from the base station using a cell-specific RRC signal, the information about each symbol type may include at least one of the following: a period of the cell-specific slot; the number of slots consisting of only downlink symbols from the cell-specific slot where the period begins; the number of downlink symbols from the first symbol of the slot immediately following the last slot consisting of only downlink symbols; the number of slots consisting of only uplink symbols from the last cell-specific slot of the period; and the number of uplink symbols immediately preceding the last slot among the slots consisting of only uplink symbols. Furthermore, when the terminal receives information about each symbol type in a slot from the base station using a cell-specific RRC signal, the information about each symbol type may include up to two slot patterns. In this case, each of the two patterns may be applied consecutively to the symbol in the time domain. Downlink symbols, uplink symbols, and flexible symbols configured based on the cell-specific RRC signal or SIB1 may be referred to as cell-specific downlink symbols, cell-specific uplink symbols, and cell-specific flexible symbols, respectively.

[0114] When the terminal receives information about each symbol type in a slot from the base station through a terminal-specific RRC signal, the cell-specific flexible symbol may be configured as a downlink symbol or an uplink symbol. In this case, the information about each symbol type may include at least one of an index for a slot in a configured period, the number of downlink symbols from the first symbol of the slot indicated by the index, and the number of uplink symbols from the last symbol of the slot indicated by the index. Furthermore, the terminal may configure all symbols in a slot to be downlink symbols, or may configure all symbols in a slot to be uplink symbols. The downlink symbols, uplink symbols, and flexible symbols configured based on the terminal-specific RRC signal may be referred to as terminal-specific downlink symbols, terminal-specific uplink symbols, and terminal-specific flexible symbols, respectively.

[0115] As another method for informing a terminal of slot format information, the base station can transmit information about the slot format to the terminal using a slot format indicator (SFI) of DCI format 2_0 included in a group common (GC)-PDCCH. The GC-PDCCH may be CRC-scrambled with the SFI-RNTI for the terminal to receive the slot format information. Hereinafter, the SFI transmitted by the GC-PDCCH may be referred to as a dynamic SFI.

[0116] The terminal may receive the dynamic SFI via the GC-PDCCH and be instructed whether a symbol in a slot is a cell-specific flexible symbol, or whether a terminal-specific flexible symbol is a downlink symbol, an uplink symbol, or a flexible symbol. In other words, only flexible symbols semi-statically configured in the terminal may be indicated as downlink symbols, uplink symbols, or flexible symbols by the dynamic SFI. The terminal does not need to expect that semi-statically configured downlink symbols or uplink symbols will be indicated as other types of symbols by the dynamic SFI. The terminal may perform blind decoding for each monitoring period configured by the base station to receive the GC-PDCCH transmitting DCI format 2_0 including the dynamic SFI. If the terminal performs blind decoding and successfully receives the GC-PDCCH, the terminal may apply information about the slot format indicated by the dynamic SFI starting from the slot in which the GC-PDCCH is received.

[0117] The terminal may be configured with a combination of slot formats that may be instructed by the base station using a dynamic SFI. The slot format combination is for each of 1 to 256 slots, and the terminal may be configured with a slot format combination for any one of the 1 to 256 slots using the dynamic SFI. The dynamic SFI may include an index indicating which slot the slot format combination applies to. Table 3 shows the slot format combination for each slot (see 3GPP TS38.213).

[0118] [Table 3]

[0119] In Table 3, D represents a downlink symbol, U represents an uplink symbol, and F represents a flexible symbol. As shown in Table 3, up to two DL / UL switchings may be allowed within one slot.

[0120] As used herein, configure, set, and instruct may be used interchangeably. That is, "to be configured," "to be set," and "to be instructed" may have the same meaning, and similarly, "to be configured," "to be set," and "to be instructed" may have the same meaning.

[0121] Subband-based full duplex: Spectrum partitioning

[0122] 12 and 13 illustrate examples of subband setting methods and signal transmission.

[0123] In a TDD or unpaired spectrum system, when a slot format is configured or instructed to a terminal, only limited time domain resources are allocated as uplink resources, which may result in problems of reduced uplink coverage, increased latency, and reduced capacity. To solve these problems, a method has been discussed in which a specific time domain resource within a cell is divided into multiple subbands in the frequency domain and used for both downlink reception and uplink transmission.

[0124] Referring to FIG. 12, a terminal may receive TDD configuration information to semi-statically configure a slot format, or may receive an SFI to dynamically instruct the slot format. Here, the TDD configuration information may include cell-specific (or cell-common) TDD configuration information (e.g., tdd-UL-DL-ConfigurationCommon) or terminal-specific TDD configuration information (e.g., tdd-UL-DL-ConfigurationDedicated). Here, D (or DL) represents downlink, U (or UL) represents uplink, and F represents flexible, and D / F (or DL / F) represents D (or DL) or F. Then, the terminal may be configured with multiple subbands in the frequency domain for specific time domain resources (e.g., at least one slot / symbol) (n2 to n3) according to subband configuration / instruction from the base station. The subband configuration / instruction information may include information about a set of consecutive RBs constituting the subband (e.g., a starting RB, the number of RBs, etc.). The multiple subbands may be subbands of the same or different formats. The subband format may include downlink (D, or DL) subbands and uplink (U, or UL) subbands. The D (or DL) subbands may be configured as one or more downlink RBs, and the U (or UL) subbands may be configured as one or more uplink RBs. The downlink RBs may refer to resources available for downlink reception, and the uplink RBs may refer to resources available for uplink transmission.

[0125] Referring to FIG. 13, a terminal may be (dynamically) instructed by a base station of multiple subbands in the frequency domain for a downlink (D or DL) slot or symbol that is semi-statically configured (e.g., TDD configuration) or dynamically instructed (e.g., SFI). In FIG. 13, the multiple subbands include two D (or DL) subbands and one U (or UL) subband. In this case, in the same symbol, resources configured or instructed to receive downlink signals or channels and resources configured or instructed to transmit uplink signals or channels may overlap in the time domain. For example, when downlink reception (e.g., CSI-RS) is scheduled in the D (or DL) subband and uplink transmission (e.g., PUSCH) is scheduled in the U (or UL) subband, they may overlap in at least one symbol (e.g., the fifth or sixth symbol). Meanwhile, when a subband is configured, a base station can perform both downlink transmission and uplink reception using the same subband symbol (full duplex), but a terminal that only supports half duplex can only perform either downlink reception or uplink transmission using the same subband symbol. Here, a subband symbol refers to a symbol in which a subband is configured. Therefore, when downlink reception and uplink transmission overlap using the same subband symbol (see the circle in the figure), the terminal and the base station may operate as follows.

[0126] 1) When downlink reception and uplink transmission belong to different terminals,

[0127] Each terminal can perform downlink reception or uplink transmission without restriction.

[0128] - A base station can simultaneously perform downlink transmission and uplink reception.

[0129] 2) When downlink reception and uplink transmission belong to the same terminal,

[0130] A terminal cannot perform downlink reception and uplink transmission simultaneously. Therefore, to resolve collisions between downlink reception and uplink transmission, the terminal's downlink reception and / or uplink transmission may be restricted.

[0131] A base station can perform downlink transmission and uplink reception simultaneously. However, since downlink reception and / or uplink transmission are restricted in the terminal, the same restrictions may also apply to the base station.

[0132] Here, the collision situation may not be limited to a case where a terminal is dynamically instructed to use multiple subbands in the frequency domain for a downlink slot or symbol that is semi-statically configured or dynamically instructed by a base station, that is, the collision situation may also include a case where a terminal is semi-statically configured to use multiple subbands in the frequency domain for a downlink slot or symbol that is semi-statically configured or dynamically instructed by a base station.

[0133] Furthermore, the collision situation may not be limited to a case where a terminal is dynamically instructed to use multiple subbands in the frequency domain for flexible slots or symbols that are semi-statically configured or dynamically instructed by a base station, that is, the collision situation may also include a case where a terminal is semi-statically configured to use multiple subbands in the frequency domain for flexible slots or symbols that are semi-statically configured or dynamically instructed by a base station.

[0134] Example: Subband-based full duplex and signal / channel transmission and reception

[0135] First, the terms used in the present invention will be summarized.

[0136] Subband-based full duplex: This refers to a scheme that supports simultaneous transmission and reception using subbands within a cell / BWP. It can also be referred to as sub-band non-overlapping full duplex (SBFD). Here, a subband refers to a frequency band configured / instructed for SBFD operation within a cell / BWP. One subband may consist of one set of contiguous (P)RBs. For examples of subband configurations / formats, see FIGS. 12 and 13. For example, in the case of an unpaired spectrum (i.e., a TDD cell / BWP), UL subbands may be configured on DL slots / symbols or flexible slots / symbols. When subbands are configured in a cell / BWP, the cell / BWP may include TDM subband sections and non-subband sections in the time domain.

[0137] - Subband interval: refers to a time interval in which a subband is configured / indicated on a cell / BWP. For example, a subband interval includes a time interval in which a UL subband is configured / indicated. For example, a subband interval includes a slot in which a UL subband is configured / indicated. For example, a subband interval includes a symbol (or a symbol set) in which a UL subband is configured / indicated. A subband interval includes a subband slot and / or a subband symbol. A subband interval may include one or more subbands in the frequency domain. When multiple subbands are configured in a subband interval, the subbands are FDM-modulated. Multiple subbands (DL subbands or UL subbands) in a subband interval may be configured to be non-overlapping in the frequency domain.

[0138] - Non-subband interval: A time interval in which a subband is not configured / indicated on a cell / BWP. A non-subband interval includes a non-subband slot and / or a non-subband symbol. A non-subband interval refers to a legacy interval or a normal interval. A non-subband interval includes at least one of a DL symbol, a flexible symbol, and an UL symbol depending on the slot format. For example, if a subband is not configured / indicated on a UL BWP, a non-subband interval includes a UL slot / symbol.

[0139] - Legacy NR system: A system that does not support or configure subband-based full-duplex operation and operates according to the existing NR method.

[0140] The problem to be solved by the present invention relates to when a signal or channel configured or instructed to be received by a terminal collides with an RO (RACH occasion), which is an opportunity for PRACH transmission, at the same symbol. The RO is configured within a PRACH slot. The PRACH slot is periodically configured in units of radio frames based on a PRACH Configuration Index, which is information from a higher layer (e.g., RRC) (see 3GPP TS 38.211 V16.9.0 (2022-06), Tables 6.3.3.2-2 to 6.3.3.2-4). One or more ROs may be configured in the time domain within a PRACH slot, and multiple ROs may be configured in the frequency domain. The number of symbols and RBs occupied by one RO may be defined differently depending on the PRACH / preamble format. FIG. 14 illustrates multiple ROs configured within a PRACH slot. This figure illustrates a case where an RO is configured for two symbol sets in the time domain (TDM) and an RO is configured for five RBs in the frequency domain (FDM) in a PRACH slot. It also illustrates a case where one RO is configured with 76 symbols in the time domain. In other words, it illustrates a case where one symbol set configuring one RO in the time domain is configured with seven symbols.

[0141] Whether an RO is valid may be determined according to the slot format configuration of the PRACH slot. The terminal can perform uplink transmission (e.g., PRACH) or downlink reception (e.g., PDSCH, CSI-RS) based on whether the RO is valid. Specifically, the terminal can perform PRACH transmission with a valid RO. Furthermore, the terminal may skip downlink reception if a valid RO (including gap symbols) and downlink reception (e.g., PDSCH reception, CSI-RS reception) overlap in the time domain. On the other hand, if an RO is invalid, the terminal cannot perform PRACH transmission with the RO. Furthermore, even if an RO (including gap symbols) and downlink reception overlap in the time domain, the terminal can perform downlink reception normally if the RO is invalid. In the existing NR system, the terminal can determine a valid RO in a TDD or unpaired spectrum as follows. Specifically, the valid RO may be determined as follows depending on whether the terminal is configured with tdd-UL-DL-ConfigurationCommon, which is information about the symbol type. The tdd-UL-DL-ConfigurationCommon may be received in cell-specific (or cell-common) RRC signaling or SIB1 (system information block 1).

[0142] - If the terminal does not have tdd-UL-DL-ConfigurationCommon configured:

[0143] The RO in a PRACH slot does not precede in time the SS / PBCH block in the same PRACH slot and is at least N symbols from the last SS / PBCH block received. gap The RO may be valid if it starts after the symbol, where the last SS / PBCH block received symbol means the last received symbol of the last SS / PBCH block before the RO.

[0144] - If the terminal is configured with tdd-UL-DL-ConfigurationCommon (Figure 15):

[0145] An RO in a PRACH slot is valid if it is on an UL symbol, does not precede in time the SS / PBCH block in the same PRACH slot, and is at least N DL symbols from the last DL symbol. gap symbol (Figure 15(a)) and at least N symbols from the last SS / PBCH block received symbol gap symbol (Figure 15(b)), the RO may be valid. Here, the last DL symbol means the last DL symbol before the RO on the DL symbol set configured by tdd-UL-DL-ConfigurationCommon. In this figure, the D symbol means a cell-common (or cell-specific) DL symbol, the F symbol means a cell-common (or cell-specific) flexible symbol, and the U symbol means a cell-common (or cell-specific) UL symbol.

[0146] Table 4 shows the N gap In the case of the PRACH preamble format B4, N gap =0.

[0147] [Table 4]

[0148] Meanwhile, according to the disclosure of this specification, a terminal may be semi-statically configured or dynamically instructed by a base station to have multiple subbands in the frequency domain for a downlink / flexible slot or symbol that is semi-statically configured or dynamically instructed. Here, the multiple subbands may include at least one UL subband, or, as another example, at least one DL subband and at least one UL subband. In this case, in addition to the above method, according to one example of the present invention, the terminal may determine a valid RO for the slot or symbol as follows:

[0149] - If the terminal does not have tdd-UL-DL-ConfigurationCommon configured:

[0150] An RO in a PRACH slot is in an uplink subband, the RO does not precede an SS / PBCH block in the same PRACH slot in the time domain, and the RO has not preceded the last SS / PBCH block received symbol by at least N gap The RO may be valid if it starts after the symbol, where the last SS / PBCH block received symbol means the last received symbol of the last SS / PBCH block before the RO.

[0151] - If the terminal is configured with tdd-UL-DL-ConfigurationCommon (Figures 16 to 19):

[0152] An RO in a PRACH slot is valid if it is on an UL symbol (Figure 16). Also, if the RO in a PRACH slot is in the UL subband (Figure 16), the RO does not precede the SS / PBCH block in the same PRACH slot in the time domain, and is at least N DL symbols from the last DL symbol. gap 17 and 18) and starts at least N symbols after the last SS / PBCH block received symbol. gapThe RO may be valid if it starts after the symbol (FIG. 19). Because UL transmission is allowed in the UL subband, the last DL symbol is limited to a DL symbol for which no UL subband is configured or indicated (i.e., a non-subband symbol). That is, subband symbols are not included in the last DL symbol. Referring to FIG. 17 and FIG. 18, the last DL symbol refers to the last DL symbol before the RO on the DL symbol set configured by tdd-UL-DL-ConfigurationCommon, excluding symbols for which UL subbands are configured (the last symbol of slot #p-1, the last symbol of slot #m-1).

[0153] 16 to 19, m, p, and q represent slot indexes, which are defined by the PRACH slot configuration and may be configured contiguously or discontinuously.

[0154] The terminal can perform UL transmission or DL ​​reception based on a valid RO (or based on whether the RO is valid or not). For example, the terminal can perform PRACH transmission with a valid RO. Furthermore, when a valid RO (including gap symbols) and downlink reception (e.g., PDSCH reception) overlap in the time domain, the terminal may be restricted in one of PRACH transmission or DL ​​reception according to the disclosure of the present invention. This will be described later with reference to FIGS. 20 to 23. On the other hand, the terminal cannot perform PRACH transmission with an invalid RO. Furthermore, the terminal's downlink reception is not restricted by an invalid RO.

[0155] The terminal may be semi-statically configured or dynamically instructed by the base station to use multiple subbands in the frequency domain for a downlink / flexible slot or symbol that is semi-statically configured or dynamically instructed. In this case, the configured or instructed resource for receiving a DL signal / channel and a valid RO may overlap in the same symbol. A terminal that supports only half duplex can only perform either DL reception or UL transmission in the same symbol, and the terminal must be able to determine (i) a valid RO and (ii) N before the valid RO. gap A DL signal / channel (e.g., PDCCH, PDSCH, or CSI-RS) may not be received (e.g., reception may be skipped) in a symbol, whereas if an RO overlapping with the DL signal / channel is not valid, the DL signal / channel may be received normally.

[0156] For example, referring to FIG. 20, the terminal may receive (i) a valid RO and (ii) N before the valid RO. gap The terminal may be configured or instructed to receive the PDSCH including the symbols overlapping with the six symbols corresponding to the valid RO. In this case, the terminal does not need to receive the PDSCH to protect the PRACH transmission in the valid RO. Meanwhile, if the terminal does not receive the PDSCH when there is no actual PRACH transmission in the valid RO, the downlink coverage may be reduced because the terminal does not receive the PDSCH even though the resources configured or instructed to receive the PDSCH in the slot are available. In the following, the terminal operation to solve this problem is proposed as follows. In the following, a valid RO is N gap symbols, i.e., a valid RO may contain {N gap symbol +RO}. gap For symbols, see Table 4.

[0157] 1) PDSCH (or SPS PDSCH) vs valid RO (Figures 20 to 23)

[0158] A terminal may be configured or instructed with multiple subbands in the frequency domain for a semi-statically configured or dynamically instructed downlink / flexible slot or symbol. The terminal may also be instructed to receive a PDSCH in accordance with a DCI format (e.g., DCI format 1_0, 1_1, or 1_2) for DL ​​scheduling in the slot or symbol (i.e., subband slot / symbol). The terminal may also be configured to receive a semi-persistent scheduling (SPS) PDSCH in the slot or symbol (i.e., subband slot / symbol) by a higher layer (e.g., RRC). When a PDSCH (or an SPS PDSCH) and a valid RO overlap in the same symbol in the slot or symbol, the terminal operates as follows.

[0159] According to the first embodiment, (a) when there is no actual PRACH transmission, a PDSCH (or an SPS PDSCH) is received, and (b) when there is an actual PRACH transmission, a PRACH is transmitted but a PDSCH does not need to be received. To solve the above problem, the first embodiment receives a PDSCH (or an SPS PDSCH) at least when there is no actual PRACH transmission, thereby preventing a reduction in downlink coverage.

[0160] According to the second embodiment, (a) when there is no actual PRACH transmission, the PDSCH (or SPS PDSCH) may be received, and (b) when there is actual PRACH transmission, the PRACH may be transmitted and the PDSCH (or SPS PDSCH) may be rate-matched and received. For example, referring to FIG. 20 , the PDSCH (or SPS PDSCH) may be instructed to be received using 14 symbols*20 RBs, valid ROs may be determined as 6 symbols*6 RBs, and the resources instructed to receive the PDSCH (or SPS PDSCH) may include all valid ROs. In this case, the UE may receive the PDSCH (or SPS PDSCH) by rate-matching only the 6 symbols*6 RBs that overlap with the valid ROs among the 14 symbols*20 RBs instructed for PDSCH (or SPS PDSCH) reception, and may transmit the PRACH using the valid ROs. In the second embodiment, even if there is actual PRACH transmission in overlapping symbols, the terminal can receive the PDSCH (or SPS PDSCH) by rate matching in resources available for downlink reception, thereby preventing a reduction in downlink coverage.

[0161] The above first and second embodiments may be applied only to PRACH transmissions configured / disclosed by a higher layer (e.g., Medium Access Control MAC), i.e., the terminal may detect DCI instructing it to receive a PDSCH (or an SPS PDSCH) and may not expect to detect DCI instructing it to transmit a PRACH in the same symbol.

[0162] Referring to Figure 21, a terminal may be configured or instructed by a base station to receive a PDSCH using eight symbols, and six symbols may be determined as valid ROs. In this case, the valid ROs and PDSCH reception may not overlap in the frequency domain, but may overlap in the time domain (i.e., two symbols). In this case, the terminal may operate differently depending on whether PDSCH reception is configured by a higher layer (e.g., Radio Resource Control (RRC)) or instructed by DCI. Here, PDSCH reception configured by a higher layer includes SPS PDSCH reception.

[0163] According to one embodiment, when PDSCH reception is instructed by a DCI format for DL ​​scheduling (e.g., DCI format 1_0, 1_1, or 1_2), the terminal may receive the PDSCH (i.e., prioritize PDSCH reception). Referring to FIG. 22, the terminal may be instructed to receive the PDSCH using 8 symbols in a downlink subband, and may determine that the valid RO is 6 symbols. In this case, the terminal may receive the PDSCH using the 8 symbols instructed by the DCI, and may not transmit the PRACH in the valid RO. This means that, at least when the terminal is instructed to perform downlink reception by the base station via DCI, the terminal may determine that it prioritizes downlink reception for downlink coverage and does not transmit PRACH. Meanwhile, unlike terminals that support half-duplex communication on subbands, the base station supports full-duplex communication. Therefore, as shown in FIG. 22, even if the PRACH transmission of one terminal in a valid RO within a subband is restricted by the PDSCH reception of the terminal, a base station supporting full duplex operation can receive PRACH from other terminals while transmitting PDSCH to the terminal in the valid RO.

[0164] According to yet another embodiment, when a terminal is configured to receive a PDSCH from a higher layer (e.g., RRC), the terminal may receive the PDSCH by rate matching and perform PRACH transmission in a valid RO. For example, the terminal may use an RxTxSwitchingGap, i.e., a gap (N) between downlink reception and uplink transmission, which is set differently depending on the symbols overlapping with the valid RO and the SCS (subcarrier spacing). gap,Rx-Tx ), and / or the gap between uplink transmission and downlink reception (N gap,Tx-Rx ) can be received by rate matching the PDSCH with symbols other than the symbols corresponding to N gap,Rx-Tx and N gap,Tx-Rx The values ​​of may be defined independently or may be defined as the same value. For convenience, the switching gap is defined as N gap It is generalized and called N gap is N gap,Rx-Tx and / or N gap,Tx-Rx Referring to FIG. 23, the UE may be configured by a higher layer (e.g., RRC) to receive the PDSCH using 8 symbols in the downlink subband, and the valid RO may be determined to be 6 symbols. In this case, the UE may receive the PDSCH using 2 symbols overlapping with the valid RO and N symbols before the valid RO. gap = 2 (i.e., N gap,Rx-Tx = 2, but is not limited thereto. The UE can receive a PDSCH having a length of 4 symbols by rate-matching the PDSCH for each symbol. In addition, the UE can transmit a PRACH even in a valid RO. This is a method of preventing a decrease in downlink coverage by rate-matching and receiving the PDSCH at least in resources where downlink reception is possible, and also enabling PRACH transmission when the UE attempts to transmit in an RO.

[0165] 2) CSI-RS vs valid RO

[0166] The UE may be configured or instructed with multiple subbands in the frequency domain for a semi-statically configured or dynamically instructed downlink / flexible slot or symbol. The UE may also be instructed to receive CSI-RS in a DCI format (e.g., DCI format 1_0, 1_1, or 1_2) for DL ​​scheduling in the slot or symbol (i.e., subband slot / symbol). When the CSI-RS and valid RO overlap in the same symbol in the slot or symbol, the UE operates as follows.

[0167] According to the first embodiment, (a) when there is no actual PRACH transmission, CSI-RS is received, and (b) when there is an actual PRACH transmission, PRACH is transmitted but CSI-RS does not need to be received. In order to solve the above problem, the first embodiment can prevent a reduction in downlink coverage by receiving CSI-RS at least when there is no actual PRACH transmission.

[0168] The above first embodiment is applicable only when CSI-RS reception is indicated by DCI and PRACH transmission is configured by a higher layer (e.g., MAC), i.e., the terminal does not need to expect to receive CSI-RS and transmit PRACH in the same symbol from a higher layer.

[0169] 3) CORESET vs valid RO

[0170] The UE may be configured or instructed with multiple subbands in the frequency domain for a semi-statically configured or dynamically instructed downlink / flexible slot or symbol. The UE may also be configured with a CORESET for monitoring the PDCCH in the slot or symbol (i.e., subband slot / symbol). When the CORESET and valid RO overlap in the same symbol in the slot or symbol, the UE operates as follows.

[0171] According to the first embodiment, (a) when there is no actual PRACH transmission, the PDCCH is monitored, and (b) when there is an actual PRACH transmission, the PRACH is transmitted and there is no need to monitor the PDCCH. To solve the above problem, the first embodiment monitors the PDCCH at least when there is no actual PRACH transmission, thereby preventing a decrease in downlink coverage. Furthermore, since the PDCCH includes control information such as resource allocation for a terminal, this may be given priority.

[0172] The first embodiment described above can be applied only when PRACH transmission is configured by a higher layer (e.g., MAC). That is, when the terminal is instructed by DCI to transmit PRACH in a symbol for which CORESET is configured, the terminal does not need to monitor the PDCCH regardless of whether an actual PRACH is transmitted in that symbol.

[0173] The above-described conflict situation between a valid RO and CORESET, PDSCH, or CSI-RS may not apply when a terminal transmits a PRACH for cell initial connection (i.e., before RRC connection). That is, in the case of a terminal before RRC connection, in the conflict situation, the terminal may not monitor the PDCCH or may not receive the PDSCH or CSI-RS. For example, a terminal before RRC connection may operate based on the legacy NR system.

[0174] Although the method and system of the present invention have been described in connection with particular embodiments, some or all of the components or operations thereof may be embodied by a computing system having a general-purpose hardware architecture.

[0175] The above description of the present invention is for illustrative purposes only, and those skilled in the art will understand that the present invention can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. Therefore, the above-described embodiments should be understood as illustrative in all respects and not restrictive. For example, each component described as a single component may be implemented in a distributed form, and similarly, each component described as a distributed component may be implemented in a combined form.

[0176] The scope of the present invention is indicated by the appended claims rather than the above detailed description, and any modifications or variations derived from the meaning and scope of the claims and their equivalents should be construed as being within the scope of the present invention.

Claims

1. A terminal used in a wireless communication system, a communication module; a processor for controlling the communication module; The processor: receiving a cell-specific radio resource control (RRC) signal regarding a slot format, the slot format including information regarding a symbol type, the symbol type including at least one of a downlink (DL) symbol, a flexible symbol, and an uplink (UL) symbol; A determination is made as to whether a physical random access channel (PRACH) occasion (RO) in a PRACH slot is valid, and the determination is made as to whether the RO has been valid for at least N DL symbols since the last DL symbol. ｇａｐ determining whether the RO is valid based on whether it starts after a symbol; and performing UL transmission or DL ​​reception based on whether the RO is valid; A plurality of subbands are configured in one frequency band in at least one slot, and the plurality of subbands include a DL subband and a UL subband; When the RO exists in the UL subband, the last DL symbol is determined based on the DL symbol configured by the cell-specific RRC signal, excluding the symbol in which the UL subband is configured.

2. The terminal of claim 1 , wherein the cell-specific RRC signal includes common time division duplex (TDD) UL-DL configuration information.

3. The determination is made based on whether the RO is within the UL subband, the RO does not precede in time a synchronization signal / physical broadcast channel (SS / PBCH) block in the PRACH slot, and the RO is within at least N DL symbols from the last DL symbol. ｇａｐ symbol after the last SS / PBCH block received symbol and at least N ｇａｐ 2. The terminal of claim 1, further comprising determining the RO to be valid if it begins after a symbol.

4. The terminal of claim 1 , wherein the determining comprises determining the RO to be valid if the RO is present on a UL symbol set configured by the cell-specific RRC signal.

5. N ｇａｐ The terminal of claim 1 , wherein the PRACH interval is determined based on a subcarrier spacing (SCS) of the PRACH.

6. N ｇａｐ is determined as follows: If the SCS of the PRACH is 1.25 kHz or 5 kHz, ｇａｐ = 0, and N if the SCS of the PRACH is 15 kHz, 30 kHz, 60 kHz, or 120 kHz ｇａｐ =2.

7. The terminal of claim 1 , wherein the terminal transmits a PRACH in the RO if the RO is valid.

8. (a) the RO is on the UL subband; (b) the RO is valid; and (c) The PDSCH (physical downlink shared channel) scheduled for the terminal is N in the time domain. ｇａｐ When overlapping with at least one of the symbol and the RO, The terminal of claim 1, wherein reception of the PDSCH is determined based on whether the PDSCH is scheduled by downlink control information (DCI) or a higher layer.

9. (a) the RO is on the UL subband; (b) the RO is valid; (c) The PDSCH (physical downlink shared channel) scheduled for the terminal is N in the time domain. ｇａｐ overlapping at least one of the symbols and the RO; and (d) if the PDSCH is scheduled by the DCI, - the PDSCH is received successfully, The terminal according to claim 8, wherein PRACH transmission is not allowed in the RO.

10. (a) the RO is on the UL subband; (b) the RO is valid; (c) The PDSCH scheduled for the terminal is N in the time domain. ｇａｐ overlapping at least one of the symbols and the RO; and (d) when the PDSCH is scheduled by the higher layer, the PDSCH is received by rate matching based on overlapping resources in the time domain; The terminal according to claim 8, wherein PRACH transmission is allowed in the RO.

11. 1. A method for use by a terminal in a wireless communication system, comprising: receiving a cell-specific radio resource control (RRC) signal regarding a slot format, the slot format including information regarding a symbol type, the symbol type including at least one of a downlink (DL) symbol, a flexible symbol, and an uplink (UL) symbol; A determination is made as to whether a physical random access channel (PRACH) occasion (RO) in a PRACH slot is valid, and the determination is made as to whether the RO has been valid for at least N DL symbols since the last DL symbol. ｇａｐ determining whether the RO is valid based on whether it begins after a symbol; and performing UL transmission or DL ​​reception based on whether the RO is valid; A plurality of subbands are configured in one frequency band in at least one slot, and the plurality of subbands include a DL subband and a UL subband; When the RO exists in the UL subband, the last DL symbol is determined based on the DL symbol configured by the cell-specific RRC signal, excluding the symbol in which the UL subband is configured.

12. The method of claim 11, wherein the cell-specific RRC signaling includes common time division duplex (TDD) UL-DL configuration information.

13. The determination is made based on whether the RO is within the UL subband, the RO does not precede in time a synchronization signal / physical broadcast channel (SS / PBCH) block in the PRACH slot, and the RO is within at least N DL symbols from the last DL symbol. ｇａｐ symbol after the last SS / PBCH block received symbol and at least N ｇａｐ 12. The method of claim 11, comprising determining the RO to be valid if it begins after a symbol.

14. The method of claim 11 , wherein the determining comprises determining the RO to be valid if the RO is present on a UL symbol set configured by the common RRC signal.

15. N ｇａｐ The method of claim 11 , wherein the PRACH subcarrier spacing (SCS) is determined based on the PRACH subcarrier spacing (SCS).

16. N ｇａｐ The method of claim 15, wherein is determined as follows: If the SCS of the PRACH is 1.25 kHz or 5 kHz, ｇａｐ = 0, and N if the SCS of the PRACH is 15 kHz, 30 kHz, 60 kHz, or 120 kHz ｇａｐ =2.

17. The method of claim 11 , further comprising transmitting a PRACH in the RO if the RO is valid.

18. (a) the RO is on the UL subband; (b) the RO is valid; and (c) The PDSCH (physical downlink shared channel) scheduled for the terminal is N in the time domain. ｇａｐ When overlapping with at least one of the symbol and the RO, The method of claim 11, wherein reception of the PDSCH is determined based on whether the PDSCH is scheduled by downlink control information (DCI) or by a higher layer.

19. (a) the RO is on the UL subband; (b) the RO is valid; (c) The PDSCH (physical downlink shared channel) scheduled for the terminal is N in the time domain. ｇａｐ overlapping at least one of the symbols and the RO; and (d) if the PDSCH is scheduled by the DCI, - the PDSCH is received successfully, The method of claim 18, wherein PRACH transmission is not allowed in the RO.

20. (a) the RO is on the UL subband; (b) the RO is valid; (c) The PDSCH scheduled for the terminal is N in the time domain. ｇａｐ overlapping at least one of the symbols and the RO; and (d) when the PDSCH is scheduled by the higher layer, the PDSCH is received by rate matching based on overlapping resources in the time domain; The method of claim 8, wherein PRACH transmission is allowed in the RO.

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