Method and device for transmitting / receiving signal in wireless communication system

Abstract

A method for a terminal receiving a signal, according to at least one embodiment among the embodiments disclosed in the present specification, may comprise: receiving, through a physical downlink control channel (PDCCH), downlink control information (DCI) for downlink scheduling; and receiving a physical downlink shared channel (PDSCH) on the basis of the DCI. On the basis that the DCI includes a specific field, the terminal may select, on the basis of the specific field, at least one transmission configuration index (TCI) state among a plurality of TCI states maintained in the terminal, and may receive the PDSCH on the basis of the selected at least one TCI state. On the basis that the DCI does not include the specific field, the terminal may receive the PDSCH on the basis of all the plurality of TCI states maintained in the terminal.

Description

Method and device for transmitting and receiving signals in a wireless communication system

[0001] The present invention relates to a wireless communication system, and more particularly, to a method and device for transmitting or receiving uplink / downlink wireless signals in a wireless communication system.

[0002] Wireless communication systems are widely deployed to provide various types of communication services, such as voice and data. Typically, wireless communication systems are multiple access systems that support communication with multiple users by sharing available system resources (e.g., bandwidth, transmission power). Examples of multiple access systems include code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), and single-carrier frequency division multiple access (SC-FDMA).

[0003] The technical problem of the present disclosure is to provide a method for efficiently performing a wireless signal transmission and reception process and a device therefor.

[0004] Other technical challenges can be inferred from the detailed description.

[0005] In one aspect, a method for a terminal to receive a signal in a wireless communication system may include receiving downlink control information (DCI) for downlink scheduling through a physical downlink control channel (PDCCH); and receiving a physical downlink shared channel (PDSCH) based on the DCI. Based on whether the DCI includes a specific field, the terminal may select at least one of a plurality of transmission configuration index (TCI) states maintained in the terminal based on the specific field, and receive the PDSCH based on the selected at least one TCI state. Based on whether the DCI does not include the specific field, the terminal may receive the PDSCH based on all of the plurality of TCI states maintained in the terminal.

[0006] The terminal can receive information about whether the DCI includes the specific field through RRC (radio resource control) signaling.

[0007] The terminal may select one of the plurality of TCI states to receive the PDSCH based on whether the reception time of the PDSCH is before a time interval for QCL (quasi-co-location). The terminal may select a first TCI state among the plurality of TCI states to receive the PDSCH.

[0008] The number of the plurality of TCI states maintained by the terminal may be 2.

[0009] The terminal may receive another DCI including a TCI field. At least one of a plurality of TCI states maintained in the terminal may be set or changed based on the TCI field. Based on whether a code point of the TCI field is related to one TCI state, the terminal may change one of the plurality of TCI states based on the code point of the TCI field, and maintain the remaining states without change. The application time of the TCI field may be determined based on a beam application time (BAT).

[0010] At least one of the above plurality of TCI states may be associated with multi-TRP (transmission reception point) operation.

[0011] According to another aspect, a processor-readable recording medium having recorded thereon a program for performing the signal receiving method described above may be provided.

[0012] According to another aspect, a terminal performing the signal receiving method described above may be provided.

[0013] According to another aspect, a device for controlling a terminal performing the signal receiving method described above may be provided.

[0014] In another aspect, a method for transmitting a signal by a base station in a wireless communication system may include transmitting downlink control information (DCI) for downlink scheduling to a terminal via a physical downlink control channel (PDCCH); and transmitting a physical downlink shared channel (PDSCH) to the terminal based on the DCI. Based on whether the DCI includes a specific field, the base station may select at least one of a plurality of transmission configuration index (TCI) states maintained in the terminal based on the specific field, and transmit the PDSCH based on the selected at least one TCI state. Based on whether the DCI does not include the specific field, the base station may transmit the PDSCH based on the plurality of TCI states maintained in the terminal.

[0015] According to another aspect, a base station performing the above-described signal transmitting method may be provided.

[0016] According to the present disclosure, wireless signal transmission and reception can be efficiently performed in a wireless communication system.

[0017] Other technical effects can be inferred from the detailed description.

[0018] Figure 1 illustrates physical channels used in a 3GPP system, which is an example of a wireless communication system, and a general signal transmission method using the channels.

[0019] Figure 2 illustrates the structure of a radio frame.

[0020] Figure 3 illustrates a resource grid of slots.

[0021] Figure 4 illustrates an example of physical channels being mapped within a slot.

[0022] Figure 5 illustrates the PDSCH and ACK / NACK transmission process.

[0023] Figure 6 illustrates a PUSCH transmission process.

[0024] Figure 7 shows an example of a CSI-related procedure.

[0025] Figure 8 is a drawing to explain the concept of the Unified TCI framework.

[0026] FIG. 9 is a diagram for explaining signal transmission and reception in a wireless communication system supporting the Unified TCI framework according to one embodiment.

[0027] Fig. 10 is a drawing for explaining terminal operation according to one embodiment.

[0028] Fig. 11 is a diagram for explaining base station operation according to one embodiment.

[0029] Figures 12 to 15 illustrate a communication system (1) and a wireless device applicable to the present disclosure.

[0030] Figure 16 illustrates a DRX (Discontinuous Reception) operation applicable to the present disclosure.

[0031] The following technologies can be used in various wireless access systems, such as CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), and SC-FDMA (single carrier frequency division multiple access). CDMA can be implemented with radio technologies such as UTRA (Universal Terrestrial Radio Access) or CDMA2000. TDMA can be implemented with radio technologies such as GSM (Global System for Mobile communications) / GPRS (General Packet Radio Service) / EDGE (Enhanced Data Rates for GSM Evolution). OFDMA can be implemented with radio technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and E-UTRA (Evolved UTRA). UTRA is a part of UMTS (Universal Mobile Telecommunications System). 3GPP (3rd Generation Partnership Project) LTE (long term evolution) is part of E-UMTS (Evolved UMTS) that uses E-UTRA, and LTE-A (Advanced) is an evolved version of 3GPP LTE. 3GPP NR (New Radio or New Radio Access Technology) is an evolved version of 3GPP LTE / LTE-A.

[0032] As more and more communication devices demand greater communication capacity, the need for improved mobile broadband communications compared to existing Radio Access Technology (RAT) is emerging. Furthermore, massive Machine Type Communications (MTC), which connects multiple devices and objects to provide diverse services anytime, anywhere, is also a key issue to be considered in next-generation communications. Furthermore, communication system design that considers reliability and latency-sensitive services / terminals is being discussed. Accordingly, the introduction of next-generation RATs that consider enhanced Mobile BroadBand Communication (eMBB), massive MTC, and Ultra-Reliable and Low Latency Communication (URLLC) is being discussed. For convenience, this technology is referred to as NR (New Radio or New RAT) in the present invention.

[0033] For clarity of explanation, the description will focus on 3GPP NR, but the technical idea of ​​the present invention is not limited thereto.

[0034] In this specification, the expression "setting" can be replaced with the expression "configure / configuration", and the two can be used interchangeably. In addition, conditional expressions (e.g., "if", "in a case", or "when", etc.) can be replaced with the expression "based on that ~~" or "in a state / status". In addition, the operation of the terminal / base station or the SW / HW configuration according to the satisfaction of the condition can be inferred / understood. In addition, if the process of the receiving (or transmitting) side can be inferred / understood from the process of the transmitting (or receiving) side in signal transmission / reception between wireless communication devices (e.g., base stations, terminals), the description thereof can be omitted. For example, signal determination / generation / encoding / transmission, etc. of the transmitting side can be understood as signal monitoring reception / decoding / determination, etc. of the receiving side. In addition, the expression that the terminal performs (or does not perform) a specific operation can also be interpreted as meaning that the base station operates while expecting / assuming (or expecting / assuming that the terminal does not perform) the specific operation. In addition, the expression that the base station performs (or does not perform) a specific operation can also be interpreted as meaning that the terminal operates while expecting / assuming (or expecting / assuming that the base station does not perform) the specific operation. In addition, the division and index of each section, embodiment, example, option, method, plan, etc. in the following description are for the convenience of explanation and should not be interpreted as meaning that each constitutes an independent invention or that each must be implemented only individually. In addition, in describing each section, embodiment, example, option, method, plan, etc., if there is no explicitly conflicting / opposing description, it can be inferred / interpreted that at least some of them can be combined and implemented together, or at least some can be implemented with the omission of each.

[0035] In a wireless communication system, a terminal receives information from a base station via the downlink (DL) and transmits it to the base station via the uplink (UL). The information transmitted and received between the base station and the terminal includes data and various control information, and various physical channels exist depending on the type and purpose of the information being transmitted and received.

[0036] Figure 1 is a drawing for explaining physical channels used in a 3GPP NR system and a general signal transmission method using them.

[0037] When a terminal is powered on again from a powered-off state or enters a new cell, it performs an initial cell search operation, such as synchronizing with the base station, in step S101. To this end, the terminal receives a Synchronization Signal Block (SSB) from the base station. The SSB includes a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS), and a Physical Broadcast Channel (PBCH). Based on the PSS / SSS, the terminal synchronizes with the base station and obtains information such as a cell ID (cell identity). In addition, the terminal can obtain broadcast information within the cell based on the PBCH. Meanwhile, the terminal can check the downlink channel status by receiving a Downlink Reference Signal (DL RS) during the initial cell search phase.

[0038] After completing the initial cell search, the terminal can obtain more specific system information by receiving a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) based on the physical downlink control channel information in step S102.

[0039] Thereafter, the terminal may perform a random access procedure such as steps S103 to S106 to complete connection to the base station. To this end, the terminal may transmit a preamble through a physical random access channel (PRACH) (S103) and receive a response message to the preamble through a physical downlink control channel and a corresponding physical downlink shared channel (S104). In the case of contention-based random access, a contention resolution procedure such as transmission of an additional physical random access channel (S105) and reception of a physical downlink control channel and a corresponding physical downlink shared channel (S106) may be performed.

[0040] The terminal that has performed the procedure as described above can then perform the general uplink / downlink signal transmission procedure, such as receiving a physical downlink control channel / physical downlink shared channel (S107) and transmitting a physical uplink shared channel (PUSCH) / physical uplink control channel (PUCCH) (S108). The control information that the terminal transmits to the base station is collectively referred to as uplink control information (UCI). UCI includes HARQ ACK / NACK (Hybrid Automatic Repeat and request Acknowledgement / Negative-ACK), SR (Scheduling Request), CSI (Channel State Information), etc. CSI includes CQI (Channel Quality Indicator), PMI (Precoding Matrix Indicator), RI (Rank Indication), etc. UCI is generally transmitted through PUCCH, but can be transmitted through PUSCH when control information and traffic data must be transmitted simultaneously. Additionally, UCI can be transmitted aperiodically via PUSCH upon request / instruction from the network.

[0041] Figure 2 illustrates the structure of a radio frame. In NR, uplink and downlink transmissions are organized into frames. Each radio frame is 10 ms long and is divided into two 5 ms half-frames (HF). Each half-frame is divided into five 1 ms sub-frames (SF). A sub-frame is divided into one or more slots, and the number of slots within a sub-frame depends on the subcarrier spacing (SCS). Each slot contains 12 or 14 OFDM (Orthogonal Frequency Division Multiplexing) symbols, depending on the cyclic prefix (CP). When a normal CP is used, each slot contains 14 OFDM symbols. When an extended CP is used, each slot contains 12 OFDM symbols.

[0042] Table 1 illustrates that when CP is normally used, the number of symbols per slot, the number of slots per frame, and the number of slots per subframe vary depending on the SCS.

[0043] SCS (15*2^u)N slot symb N frame,u slot N subframe,u slot 15KHz (u=0)1410130KHz (u=1)1420260KHz (u=2)14404120KHz (u=3)14808240KHz (u=4)1416016

[0044] * N slot symb : Number of symbols in the slot

[0045] * N frame,u slot : Number of slots in the frame

[0046] * N subframe,u slot : Number of slots in a subframe

[0047] Table 2 illustrates that when extended CP is used, the number of symbols per slot, the number of slots per frame, and the number of slots per subframe vary depending on the SCS.

[0048] SCS (15*2^u)N slot symb N frame,u slot N subframe,u slot 60KHz (u=2)12404

[0049] The structure of the frame is only an example, and the number of subframes, number of slots, and number of symbols in the frame can be varied.

[0050] In an NR system, OFDM numerology (e.g., SCS) may be set differently between multiple cells that are merged into a single terminal. Accordingly, the (absolute time) interval of a time resource (e.g., SF, slot, or TTI) (conveniently referred to as TU (Time Unit)) consisting of the same number of symbols may be set differently between the merged cells. Here, the symbol may include an OFDM symbol (or CP-OFDM symbol), an SC-FDMA symbol (or Discrete Fourier Transform-spread-OFDM, DFT-s-OFDM symbol).

[0051] Figure 3 illustrates a resource grid of a slot. A slot contains multiple symbols in the time domain. For example, in the case of a regular CP, one slot contains 14 symbols, but in the case of an extended CP, one slot contains 12 symbols. A carrier contains multiple subcarriers in the frequency domain. A Resource Block (RB) is defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. A Bandwidth Part (BWP) is defined as multiple consecutive Physical RBs (PRBs) in the frequency domain and can correspond to a single numerology (e.g., SCS, CP length, etc.). A carrier can contain up to N (e.g., 5) BWPs. Data communication is performed through activated BWPs, and only one BWP can be activated for a single terminal. Each element in the resource grid is referred to as a Resource Element (RE), to which one complex symbol can be mapped.

[0052] Figure 4 illustrates an example of how physical channels are mapped within a slot. A PDCCH can be transmitted in the DL control region, and a PDSCH can be transmitted in the DL data region. A PUCCH can be transmitted in the UL control region, and a PUSCH can be transmitted in the UL data region. GP provides a time gap between the base station and the terminal when switching from transmission mode to reception mode or from reception mode to transmission mode. Some symbols within a subframe at the time of transition from DL to UL can be set as GP.

[0053] Below, each physical channel is described in more detail.

[0054] The PDCCH carries Downlink Control Information (DCI). For example, the PCCCH (i.e., DCI) carries the transmission format and resource allocation of the downlink shared channel (DL-SCH), resource allocation information for the uplink shared channel (UL-SCH), paging information for the paging channel (PCH), system information on the DL-SCH, resource allocation information for upper layer control messages such as random access responses transmitted on the PDSCH, transmission power control commands, activation / deactivation of Configured Scheduling (CS), etc. The DCI includes a cyclic redundancy check (CRC), which is masked / scrambled with various identifiers (e.g., Radio Network Temporary Identifier, RNTI) depending on the owner or usage of the PDCCH. For example, if the PDCCH is for a specific terminal, the CRC is masked with the terminal identifier (e.g., Cell-RNTI, C-RNTI). If the PDCCH is for paging, the CRC is masked with the Paging-RNTI (P-RNTI). If the PDCCH is for system information (e.g., a System Information Block, SIB), the CRC is masked with the System Information RNTI (SI-RNTI). If the PDCCH is for a random access response, the CRC is masked with the Random Access-RNTI (RA-RNTI).

[0055] The PDCCH consists of 1, 2, 4, 8, or 16 Control Channel Elements (CCEs) depending on the Aggregation Level (AL). A CCE is a logical allocation unit used to provide a PDCCH with a predetermined code rate depending on the radio channel status. A CCE consists of six Resource Element Groups (REGs). A REG is defined as one OFDM symbol and one (P)RB. The PDCCH is transmitted through a Control Resource Set (CORESET). A CORESET is defined as a set of REGs with a given numerology (e.g., SCS, CP length, etc.). Multiple CORESETs for a single UE can overlap in the time / frequency domain. A CORESET can be configured through system information (e.g., Master Information Block, MIB) or UE-specific upper layer (e.g., Radio Resource Control, RRC, layer) signaling. Specifically, the number of RBs and the number of OFDM symbols (up to 3) that constitute the CORESET can be set by upper layer signaling.

[0056] To receive / detect PDCCH, the UE monitors PDCCH candidates. PDCCH candidates represent the CCE(s) that the UE should monitor for PDCCH detection. Each PDCCH candidate is defined as 1, 2, 4, 8, or 16 CCEs depending on the AL. Monitoring involves (blind) decoding the PDCCH candidates. The set of PDCCH candidates that the UE monitors is defined as a PDCCH Search Space (SS). The search space includes a Common Search Space (CSS) or a UE-specific search space (USS). The UE can acquire DCI by monitoring PDCCH candidates in one or more search spaces configured by the MIB or higher-layer signaling. Each CORESET is associated with one or more search spaces, and each search space is associated with one COREST. The search space can be defined based on the following parameters.

[0057] - controlResourceSetId: Indicates the CORESET associated with the search space.

[0058] - monitoringSlotPeriodicityAndOffset: Indicates the PDCCH monitoring period (in slots) and the PDCCH monitoring interval offset (in slots).

[0059] - monitoringSymbolsWithinSlot: Indicates the PDCCH monitoring symbols within the slot (e.g., the first symbol(s) of the CORESET).

[0060] - nrofCandidates: AL={1, 2, 4, 8, 16} indicates the number of PDCCH candidates (one of 0, 1, 2, 3, 4, 5, 6, 8)

[0061] * An opportunity (e.g., time / frequency resource) for monitoring PDCCH candidates is defined as a PDCCH (monitoring) opportunity. One or more PDCCH (monitoring) opportunities can be configured within a slot.

[0062] Table 3 illustrates the characteristics of each search space type.

[0063] TypeSearch SpaceRNTIUse CaseType0-PDCCHCommonSI-RNTI on a primary cellSIB DecodingType0A-PDCCHCommonSI-RNTI on a primary cellSIB DecodingType1-PDCCHCommonRA-RNTI or TC-RNTI on a primary cellMsg2, Msg4 decoding in RACHType2-PDCCHCommonP-RNTI on a primary cellPaging DecodingType3-PDCCHCommonINT-RNTI, SFI-RNTI, TPC-PUSCH-RNTI, TPC-PUCCH-RNTI, TPC-SRS-RNTI, C-RNTI, MCS-C-RNTI, or CS-RNTI(s)UE SpecificUE SpecificC-RNTI, or MCS-C-RNTI, or CS-RNTI(s)User specific PDSCH decoding

[0064] Table 4 illustrates DCI formats transmitted via PDCCH.

[0065] DCI formatUsage0_0Scheduling of PUSCH in one cell0_1Scheduling of PUSCH in one cell1_0Scheduling of PDSCH in one cell1_1Scheduling of PDSCH in one cell2_0Notifying a group of UEs of the slot format2_1Notifying a group of UEs of the PRB(s) and OFDM symbol(s) where UE may assume no transmission is intended for the UE2_2Transmission of TPC commands for PUCCH and PUSCH2_3Transmission of a group of TPC commands for SRS transmissions by one or more UEs

[0066] DCI format 0_0 is used to schedule a TB-based (or TB-level) PUSCH, and DCI format 0_1 ​​can be used to schedule a TB-based (or TB-level) PUSCH or a CBG (Code Block Group)-based (or CBG-level) PUSCH. DCI format 1_0 is used to schedule a TB-based (or TB-level) PDSCH, and DCI format 1_1 can be used to schedule a TB-based (or TB-level) PDSCH or a CBG-based (or CBG-level) PDSCH (DL grant DCI). DCI format 0_0 / 0_1 may be referred to as UL grant DCI or UL scheduling information, and DCI format 1_0 / 1_1 may be referred to as DL grant DCI or DL ​​scheduling information. DCI format 2_0 is used to convey dynamic slot format information (e.g., dynamic SFI) to the terminal, and DCI format 2_1 is used to convey downlink pre-emption information to the terminal. DCI format 2_0 and / or DCI format 2_1 can be conveyed to the terminals within a group through the group common PDCCH, which is a PDCCH conveyed to the terminals defined as a group.

[0067] DCI format 0_0 and DCI format 1_0 may be referred to as fallback DCI formats, while DCI format 0_1 ​​and DCI format 1_1 may be referred to as non-fallback DCI formats. In the fallback DCI format, the DCI size / field configuration remains the same regardless of the terminal configuration. On the other hand, in the non-fallback DCI format, the DCI size / field configuration varies depending on the terminal configuration.

[0068] PDSCH carries downlink data (e.g., DL-SCH transport block, DL-SCH TB) and applies modulation methods such as Quadrature Phase Shift Keying (QPSK), 16 Quadrature Amplitude Modulation (QAM), 64 QAM, and 256 QAM. TB is encoded to generate a codeword. PDSCH can carry up to two codewords. Scrambling and modulation mapping are performed for each codeword, and modulation symbols generated from each codeword can be mapped to one or more layers. Each layer is mapped to resources along with a Demodulation Reference Signal (DMRS), generated as an OFDM symbol signal, and transmitted through the corresponding antenna port.

[0069] PUCCH carries Uplink Control Information (UCI). UCI includes:

[0070] - SR (Scheduling Request): Information used to request UL-SCH resources.

[0071] - HARQ(Hybrid Automatic Repeat reQuest)-ACK(Acknowledgement): This is a response to a downlink data packet (e.g., codeword) on the PDSCH. It indicates whether the downlink data packet was successfully received. One HARQ-ACK bit can be transmitted in response to a single codeword, and two HARQ-ACK bits can be transmitted in response to two codewords. The HARQ-ACK response includes a positive ACK (simply, ACK), a negative ACK (NACK), a DTX, or a NACK / DTX. Here, HARQ-ACK is used interchangeably with HARQ ACK / NACK and ACK / NACK.

[0072] - CSI (Channel State Information): Feedback information for the downlink channel. MIMO (Multiple Input Multiple Output)-related feedback information includes the Rank Indicator (RI) and Precoding Matrix Indicator (PMI).

[0073] Table 5 illustrates PUCCH formats. Depending on the PUCCH transmission length, they can be classified into Short PUCCH (formats 0 and 2) and Long PUCCH (formats 1, 3, and 4).

[0074] PUCCH formatLength in OFDM symbols N PUCCH symb Number of bitsUsageEtc01 - 2≤2HARQ, SRSequence selection14 - 14≤2HARQ, [SR]Sequence modulation21 - 2>2HARQ, CSI, [SR]CP-OFDM34 - 14>2HARQ, CSI, [SR]DFT-s-OFDM(no UE multiplexing)44 - 14>2HARQ, CSI, [SR]DFT-s-OFDM(Pre DFT OCC)

[0075] PUCCH format 0 carries UCI of up to 2 bits in size and is mapped and transmitted based on sequence. Specifically, the terminal transmits a specific UCI to the base station by transmitting one of multiple sequences through the PUCCH of PUCCH format 0. The terminal transmits the PUCCH of PUCCH format 0 within the PUCCH resources for the corresponding SR configuration only when transmitting a positive SR.

[0076] PUCCH format 1 carries UCI of up to 2 bits in size, and modulation symbols are spread in the time domain using an orthogonal cover code (OCC) (which is set differently depending on whether frequency hopping is used). DMRS are transmitted in symbols where modulation symbols are not transmitted (i.e., transmitted using Time Division Multiplexing (TDM).

[0077] PUCCH format 2 carries UCI with a bit size greater than 2 bits, and modulation symbols are transmitted by frequency division multiplexing (FDM) with DMRS. DM-RSs are located at symbol indices #1, #4, #7, and #10 within a given resource block with a density of 1 / 3. Pseudo Noise (PN) sequences are used for DM_RS sequences. Frequency hopping can be enabled for 2-symbol PUCCH format 2.

[0078] PUCCH format 3 does not multiplex terminals within the same physical resource blocks and carries UCI with a bit size greater than 2 bits. In other words, PUCCH resources in PUCCH format 3 do not include orthogonal cover codes. Modulation symbols are transmitted through time division multiplexing (TDM) with DMRS.

[0079] PUCCH format 4 supports multiplexing of up to four terminals within the same physical resource blocks and carries UCI with a bit size greater than 2 bits. In other words, PUCCH resources in PUCCH format 3 include orthogonal cover codes. Modulation symbols are transmitted through time division multiplexing (TDM) with DMRS.

[0080] At least one of one or more configured cells in a terminal may be configured for PUCCH transmission. At least the primary cell may be configured as a cell for PUCCH transmission. At least one PUCCH cell group may be configured in the terminal based on at least one cell configured for PUCCH transmission, and each PUCCH cell group includes one or more cells. The PUCCH cell group may be simply referred to as a PUCCH group. PUCCH transmission may be configured not only for the primary cell but also for the SCell, and the primary cell belongs to the primary PUCCH group, and the PUCCH-SCell configured for PUCCH transmission belongs to the secondary PUCCH group. For cells belonging to the primary PUCCH group, the PUCCH on the primary cell may be used, and for cells belonging to the secondary PUCCH group, the PUCCH on the PUCCH-SCell may be used.

[0081] PUSCH carries uplink data (e.g., UL-SCH transport block, UL-SCH TB) and / or uplink control information (UCI), and is transmitted based on a CP-OFDM (Cyclic Prefix - Orthogonal Frequency Division Multiplexing) waveform or a DFT-s-OFDM (Discrete Fourier Transform - spread - Orthogonal Frequency Division Multiplexing) waveform. When the PUSCH is transmitted based on a DFT-s-OFDM waveform, the UE transmits the PUSCH by applying transform precoding. For example, when transform precoding is disabled (e.g., transform precoding is disabled), the UE transmits the PUSCH based on the CP-OFDM waveform, and when transform precoding is enabled (e.g., transform precoding is enabled), the UE can transmit the PUSCH based on the CP-OFDM waveform or the DFT-s-OFDM waveform. PUSCH transmissions can be dynamically scheduled by UL grants in DCI, or semi-statically scheduled (configured grant) based on higher layer (e.g., RRC) signaling (and / or Layer 1 (L1) signaling (e.g., PDCCH)). PUSCH transmissions can be performed in a codebook-based or non-codebook-based manner.

[0082] Figure 5 illustrates an ACK / NACK transmission process. Referring to Figure 5, a terminal can detect a PDCCH in slot #n. Here, the PDCCH includes downlink scheduling information (e.g., DCI formats 1_0, 1_1), and the PDCCH indicates a DL assignment-to-PDSCH offset (K0) and a PDSCH-HARQ-ACK reporting offset (K1). For example, DCI formats 1_0, 1_1 can include the following information:

[0083] - Frequency domain resource assignment: Indicates the set of RBs allocated to the PDSCH.

[0084] - Time domain resource assignment: K0 (e.g., slot offset), indicates the starting position of the PDSCH within slot #n+K0 (e.g., OFDM symbol index), and the length of the PDSCH (e.g., number of OFDM symbols).

[0085] - PDSCH-to-HARQ_feedback timing indicator: Indicates K1

[0086] - HARQ process number (4 bits): Indicates the HARQ process ID (Identity) for data (e.g., PDSCH, TB)

[0087] - PUCCH resource indicator (PRI): Indicates the PUCCH resource to be used for UCI transmission among multiple PUCCH resources within the PUCCH resource set.

[0088] Afterwards, the terminal receives PDSCH from slot #(n+K0) according to the scheduling information of slot #n, and when reception of PDSCH is finished in slot #n1 (where, n+K0≤n1), UCI can be transmitted through PUCCH in slot #(n1+K1). Here, UCI may include HARQ-ACK response for PDSCH. In Fig. 5, for convenience, it is assumed that SCS for PDSCH and SCS for PUCCH are the same and slot # n1 = slot #n+K0, but the present invention is not limited thereto. If the SCSs are different, K1 can be indicated / interpreted based on the SCS of PUCCH.

[0089] When the PDSCH is configured to transmit at most 1 TB, the HARQ-ACK response may consist of 1 bit. When the PDSCH is configured to transmit at most 2 TB, the HARQ-ACK response may consist of 2 bits if spatial bundling is not configured, and may consist of 1 bit if spatial bundling is configured. When the HARQ-ACK transmission timing for multiple PDSCHs is designated as slot #(n+K1), the UCI transmitted in slot #(n+K1) includes HARQ-ACK responses for multiple PDSCHs.

[0090] Whether a UE should perform spatial bundling for a HARQ-ACK response can be configured (e.g., via RRC / higher layer signaling) for each cell group. For example, spatial bundling can be individually configured for each HARQ-ACK response transmitted over the PUCCH and / or each HARQ-ACK response transmitted over the PUSCH.

[0091] Spatial bundling can be supported when the maximum number of TBs (or codewords) that can be received at a time (or scheduled via 1 DCI) in the serving cell is 2 (or more than 2) (e.g., when the upper layer parameter maxNrofCodeWordsScheduledByDCI corresponds to 2-TB). Meanwhile, more than 4 layers can be used for 2-TB transmission, and up to 4 layers can be used for 1-TB transmission. Consequently, when spatial bundling is configured for the cell group, spatial bundling can be performed for serving cells that can schedule more than 4 layers among the serving cells in the cell group. On the serving cell, a terminal that wishes to transmit a HARQ-ACK response via spatial bundling can generate the HARQ-ACK response by performing a (bit-wise) logical AND operation on the A / N bits for multiple TBs.

[0092] For example, assuming that a terminal receives a DCI scheduling 2 TB and receives 2 TB via PDSCH based on the DCI, the terminal performing spatial bundling can generate a single A / N bit by logically ANDing the first A / N bit for the first TB and the second A / N bit for the second TB. Consequently, if both the first TB and the second TB are ACK, the terminal reports the ACK bit value to the base station, and if either TB is NACK, the terminal reports the NACK bit value to the base station.

[0093] For example, if only 1-TB is actually scheduled on a serving cell configured to receive 2-TB, the terminal can generate a single A / N bit by logically ANDing the A / N bit for the 1-TB with bit value 1. Consequently, the terminal reports the A / N bit for the 1-TB to the base station as is.

[0094] A base station / terminal has multiple parallel DL HARQ processes for DL ​​transmission. These multiple parallel HARQ processes allow DL transmissions to be performed continuously while waiting for HARQ feedback regarding the success or failure of the previous DL transmission. Each HARQ process is associated with a HARQ buffer in the MAC (Medium Access Control) layer. Each DL HARQ process manages state variables such as the number of transmissions of MAC Physical Data Blocks (PDUs) in the buffer, HARQ feedback for MAC PDUs in the buffer, and the current redundancy version. Each HARQ process is identified by a HARQ process ID.

[0095] Figure 6 illustrates a PUSCH transmission process. Referring to Figure 6, a terminal can detect a PDCCH in slot #n. Here, the PDCCH includes uplink scheduling information (e.g., DCI formats 0_0 and 0_1). DCI formats 0_0 and 0_1 can include the following information.

[0096] - Frequency domain resource assignment: Indicates the set of RBs allocated to PUSCH.

[0097] - Time domain resource assignment: Slot offset K2 indicates the starting position (e.g., symbol index) and length (e.g., number of OFDM symbols) of the PUSCH within the slot. The starting symbol and length can be indicated through SLIV (Start and Length Indicator Value) or can be indicated separately.

[0098] Thereafter, the terminal can transmit a PUSCH in slot #(n+K2) according to the scheduling information of slot #n. Here, the PUSCH includes a UL-SCH TB.

[0099] CSI-related actions

[0100] Figure 7 shows an example of a CSI-related procedure.

[0101] The terminal receives configuration information related to CSI from the base station via RRC signaling (710). The configuration information related to CSI may include at least one of CSI-IM (interference management) resource-related information, CSI measurement configuration-related information, CSI resource configuration-related information, CSI-RS resource-related information, or CSI report configuration-related information.

[0102] - CSI-IM resources can be configured for interference measurement (IM) of the terminal. In the time domain, the CSI-IM resource set can be configured periodically, semi-persistently, or aperiodicly. The CSI-IM resources can be configured as Zero Power (ZP)-CSI-RS for the terminal. The ZP-CSI-RS can be configured separately from the Non-Zero Power (NZP)-CSI-RS.

[0103] - The UE may assume that the CSI-RS resource(s) for channel measurement configured for one CSI reporting and the CSI-IM / NZP CSI-RS resource(s) for interference measurement (when NZP CSI-RS resource(s) are used for interference measurement) are in a QCL relationship with respect to 'QCL-TypeD' per resource.

[0104] - The CSI resource configuration may include at least one of a CSI-IM resource for interference measurement, an NZP CSI-RS resource for interference measurement, and an NZP CSI-RS resource for channel measurement. The CMR (channel measurement resource) may be an NZP CSI-RS for CSI acquisition, and the IMR (Interference measurement resource) may be an NZP CSI-RS for CSI-IM and IM.

[0105] - CSI-RS can be configured for one or more terminals. Different CSI-RS configurations may be provided for each terminal, or the same CSI-RS configuration may be provided to multiple terminals. CSI-RS can support up to 32 antenna ports. CSI-RS corresponding to N (N is 1 or greater) antenna ports can be mapped to N RE locations within a time-frequency unit corresponding to one slot and one RB. When N is 2 or greater, N-port CSI-RS can be multiplexed using CDM, FDM, and / or TDM schemes. CSI-RS can be mapped to REs other than REs to which CORESET, DMRS, and SSB are mapped. In the frequency domain, CSI-RS can be configured for the entire bandwidth, a portion of the bandwidth (BWP), or a portion of the bandwidth. CSI-RS may be transmitted in each RB within the bandwidth for which CSI-RS is configured (i.e., density = 1), or in every second RB (e.g., even or odd RB) (i.e., density = 1 / 2). When CSI-RS is used as a Tracking Reference Signal (TRS), a single-port CSI-RS may be mapped on three subcarriers in each resource block (i.e., density = 3). One or more CSI-RS resource sets may be configured for a UE in the time domain. Each CSI-RS resource set may include one or more CSI-RS configurations. Each CSI-RS resource set may be configured periodically, semi-persistently, or aperiodicly.

[0106] - The CSI report configuration may include configurations for feedback type, measurement resources, report type, etc. The NZP-CSI-RS resource set may be used for the CSI report configuration of the corresponding terminal. The NZP-CSI-RS resource set may be associated with CSI-RS or SSB. In addition, multiple periodic NZP-CSI-RS resource sets may be configured as TRS resource sets. (i) The feedback type may include a Channel Quality Indicator (CQI), a Precoding Matrix Indicator (PMI), a CSI-RS Resource Indicator (CRI), an SSB Resource block Indicator (SSBRI), a Layer Indicator (LI), a Rank Indicator (RI), a Layer 1-Reference Signal Received Strength (RSRP), etc. (ii) Measurement resources may include configurations for downlink signals and / or downlink resources on which the terminal performs measurements to determine feedback information. The measurement resources may be configured as ZP and / or NZP CSI-RS resource sets associated with CSI reporting configurations. The NZP CSI-RS resource set may include a CSI-RS set or an SSB set. For example, L1-RSRP may be measured for a CSI-RS set or an SSB set. (iii) Reporting types may include configurations for a time point at which the terminal performs reporting and an uplink channel, etc. The reporting time point may be configured as periodic, semi-persistent, or aperiodic. Periodic CSI reporting may be transmitted on PUCCH. Semi-persistent CSI reporting may be transmitted on PUCCH or PUSCH based on a MAC CE indicating activation / deactivation. Aperiodic CSI reporting may be indicated by DCI signaling.For example, the CSI request field of an uplink grant may indicate one of several report trigger sizes. Aperiodic CSI reports may be transmitted on the PUSCH.

[0107] The terminal measures CSI based on configuration information related to CSI. CSI measurement may include a procedure of receiving a CSI-RS (720) and computing the received CSI-RS to acquire CSI (730).

[0108] The UE can transmit a CSI report to the base station (740). For the CSI report, the time and frequency resources that the UE can use are controlled by the base station. The CSI (channel state information) can include at least one of a channel quality indicator (CQI), a precoding matrix indicator (PMI), a CSI-RS resource indicator (CRI), an SS / PBCH block resource indicator (SSBRI), a layer indicator (LI), a rank indicator (RI), L1-RSRP, and / or L-SINR.

[0109] The time domain behavior of CSI reporting supports periodic, semi-persistent, and aperiodic. i) Periodic CSI reporting is performed on short PUCCH and long PUCCH. The periodicity and slot offset of periodic CSI reporting can be configured by RRC, and refer to the CSI-ReportConfig IE. ii) SP (semi-periodic) CSI reporting is performed on short PUCCH, long PUCCH, or PUSCH. In case of SP CSI on short / long PUCCH, the periodicity and slot offset are configured by RRC, and CSI reporting is activated / deactivated by separate MAC CE / DCI. In case of SP CSI on PUSCH, the periodicity of SP CSI reporting is configured by RRC, but the slot offset is not configured by RRC, and SP CSI reporting is activated / deactivated by DCI (format 0_1). For SP CSI reporting on PUSCH, a separate RNTI (SP-CSI C-RNTI) is used. The initial CSI reporting timing follows the PUSCH time domain allocation value indicated in the DCI, and subsequent CSI reporting timings follow the cycle set by RRC. DCI format 0_1 ​​includes a CSI request field and can activate / deactivate a specific configured SP-CSI trigger state. SP CSI reporting has the same or similar activation / deactivation mechanism as the data transmission mechanism on the SPS PUSCH.iii) Aperiodic CSI reporting is performed on PUSCH and is triggered by DCI. In this case, information related to the triggering of aperiodic CSI reporting can be transmitted / indicated / configured via MAC-CE. For AP CSI with AP CSI-RS, the AP CSI-RS timing is configured by RRC, and the timing for AP CSI reporting is dynamically controlled by DCI.

[0110] QCL (quasi-co location)

[0111] Two antenna ports are quasi-co-located if the channel properties of one antenna port can be inferred from the channel properties of the other antenna port. The channel properties may include one or more of Delay spread, Doppler spread, Frequency / Doppler shift, Average received power, Received Timing / average delay, and Spatial RX parameters.

[0112] Regarding PDCCH / PDSCH QCL, multiple Transmission Configuration Indication (TCI) states can be configured to the terminal via higher layer signaling. Up to 64 TCI states can be configured via RRC for PDCCH QCL, and up to 128 TCI states can be configured via RRC for PDSCH QCL. For PDSCH QCL, a list for configuring multiple TCI-States can be provided via the higher layer parameter PDSCH-Config.

[0113] Each TCI-State is associated with one or two DL reference signals and a QCL configuration parameter between the DM-RS port of the PDSCH / PDSCH. The QCL configuration parameter may include qcl-Type1 for the first DL RS and qcl-Type2 for the second DL RS. The QCL type may correspond to one of the following:

[0114] - 'QCL-TypeA': {Doppler shift, Doppler spread, average delay, delay spread}

[0115] - 'QCL-TypeB': {Doppler shift, Doppler spread}

[0116] - 'QCL-TypeC': {Doppler shift, average delay}

[0117] - 'QCL-TypeD': {Spatial Rx parameter}

[0118] TCI states set through RRC signaling are deactivated by default.

[0119] For PDSCH QCL, up to eight TCI states can be activated through MAC CE among the RRC configured TCI states. The TCI field included in the DCI scheduling the PDSCH can indicate one of the activated TCI states (e.g., if the provision of the TCI field in the corresponding DCI is activated via RRC signaling), and the UE can receive the PDSCH based on the QCL information corresponding to the indicated TCI state.

[0120] For PDCCH QCL, one TCI state can be activated for the corresponding CORESET through MAC CE among the RRC configured TCI states. To receive the PDCCH in the corresponding CORESET, the UE can receive the PDCCH based on the QCL information corresponding to the activated TCI state.

[0121] M-TRP (multiple-transmission / reception point) related operations

[0122] The M-TRP transmission method, in which M TRPs transmit data to one terminal, can be broadly divided into two types: eMBB M-TRP transmission, which is a method for increasing the transmission rate, and URLLC M-TRP transmission, which is a method for increasing the reception success rate and reducing latency.

[0123] Meanwhile, the DL M-TRP URLLC transmission method refers to a method in which multiple TRPs transmit the same data / DCI using different space (e.g., layer / port) / time / frequency resources. For example, TRP 1 can transmit specific data / DCI in resource 1, and TRP 2 can transmit the specific data / DCI (i.e., the same data / DCI) in resource 2.

[0124] That is, when the DL M-TRP URLLC transmission method is set, the terminal can receive the same data / DCI using different space / time / frequency resources. At this time, the terminal can receive an indication from the base station regarding the QCL RS / type (i.e., DL TCI state) used in the space / time / frequency resources for receiving the corresponding data / DCI.

[0125] For example, if the corresponding data / DCI is received from resource 1 and resource 2, the terminal can be instructed by the base station about the DL TCI state used in resource 1 and the DL TCI state used in resource 2. By receiving the corresponding data / DCI through resource 1 and resource 2, high reliability can be achieved. This M-TRP URLLC transmission method can be applied to PDSCH / PDCCH.

[0126] UL M-TRP URLLC transmission method refers to a method in which multiple TRPs receive the same data / UCI from a terminal using different space / time / frequency resources. For example, TRP 1 can receive the same data / UCI from a terminal on resource 1, and TRP 2 can receive the same data / UCI from a terminal on resource 2. In addition, TRP 1 and TRP 2 can share the data / UCI received from the terminal through a backhaul link (connected between TRPs).

[0127] That is, when the UL M-TRP URLLC transmission method is set, the terminal can transmit the same data / UCI to each TRP using different space / time / frequency resources. At this time, the terminal can be instructed by the base station about the Tx beam and Tx power (i.e., UL TCI state) to be used in the space / time / frequency resources for transmitting the same data / UCI. For example, when the same data / UCI is transmitted in resource 1 and resource 2, the terminal can be instructed by the base station about the UL TCI state used in resource 1 and the UL TCI state used in resource 2. This UL M-TRP URLLC can be applied to PUSCH / PUCCH.

[0128] In addition, from the perspective of DCI transmission, the M-TRP transmission method can be divided into i) M-TRP transmission method based on M-DCI (multiple DCI) in which each TRP transmits a different DCI, and ii) M-TRP transmission method based on S-DCI (single DCI) in which one TRP transmits a DCI. For example, in the case of S-DCI, all scheduling information for data transmitted by an M-TRP must be transmitted through a single DCI, so it can be used in an ideal BH (ideal BackHaul) environment in which dynamic cooperation between two TRPs is possible.

[0129] In relation to M-TRP transmission and reception in Rel-16 NR standardization, PDSCH transmission and reception according to S-DCI-based M-TRP transmission method and M-DCI-based M-TRP transmission method are supported.

[0130] First, we will look at the S-DCI-based M-TRP PDSCH transmission method.

[0131] S-DCI-based M-TRP PDSCH transmission can use one of SDM / FDM / TDM methods. In the case of SDM, the base station transmits one TB using multiple layers, and transmits layers belonging to different DMRS CDM groups using different transmit beams (i.e., QCL RS or TCI states). This can increase the number of layers compared to the existing S-TRP transmission method, thereby improving transmission capacity. In addition, when one TB is transmitted using multiple layers, some layers are transmitted to TRP 1 and the remaining layers are transmitted to TRP 2, which can improve channel reliability due to diversity gain.

[0132] For FDM, two schemes, scheme 2a and 2b, are supported. Here, scheme 2a transmits one TB to multi-RBs, but transmits RBs belonging to different RB groups with different Tx beams (i.e., QCL RS or TCI states). Scheme 2b transmits the same TB to different RB groups, but transmits RBs belonging to different RB groups with different Tx beams (i.e., QCL RS or TCI states). For TDM, two schemes, scheme 3 and 4, are supported. Here, scheme 4 (i.e., inter-slot TDM) repeatedly transmits the same TB in multiple slots, but transmits slots belonging to different slot groups with different Tx beams (i.e., QCL RS or TCI states). On the other hand, Scheme 3 (i.e., intra-slot TDM) repeatedly transmits the same TB in multiple OFDM symbol groups, but transmits some OFDM symbol groups and the remaining OFDM symbol groups with different Tx beams (i.e., QCL RS or TCI state).

[0133] Next, we will look at the M-DCI-based M-TRP PDSCH transmission method.

[0134] M-DCI based MTRP PDSCH transmission is a method in which each TRP schedules and transmits PDSCH through DCI. That is, TRP 1 transmits PDSCH 1 through DCI 1, and TRP 2 transmits PDSCH 2 through DCI 2. When PDSCH 1 and PDSCH 2 overlap in the same frequency / time resource, two PDSCHs are received for the same RE, which increases resource efficiency and increases transmission capacity. To this end, the concept of a CORESET pool, which refers to a group of multiple CORESETs, was introduced. For example, TRP 1 transmits a PDCCH through a CORESET belonging to CORESET pool 0, and also transmits the PDSCH scheduled by the PDCCH. TRP 2 transmits a PDCCH through a CORESET belonging to CORESET pool 1, and also transmits the PDSCH scheduled by the PDCCH.

[0135] Even for PUSCH, specific TRPs can schedule PUSCH transmissions to UEs via CORESETs within each COERSET pool. For example, some PUCCH resources may be scheduled by TRP 1, while the remaining PUCCH resources may be scheduled by TRP 2. UEs can transmit independent PUSCH / PUCCHs for each of TRPs 1 and 2.

[0136] In addition, the terminal may recognize the PUSCH (or PUCCH) scheduled by the DCI received based on different CORESETs (or CORESETs belonging to different CORESET groups) as a PUSCH (or PUCCH) transmitted to different TRPs or as a PUSCH (or PUCCH) of different TRPs. In addition, the method for UL transmission (e.g., PUSCH / PUCCH) transmitted to different TRPs can be equally applied to UL transmission transmitted to different panels belonging to the same TRP.

[0137] Hereinafter, the CORESET group ID (or COERSET pool index having the same meaning) may mean an index / identification information (e.g., ID) for distinguishing the CORESET for each TRP / panel. And the CORESET group may mean a group / union of CORESETs distinguished by an index / identification information (e.g., ID) / CORESET group ID for distinguishing the CORESET for each TRP / panel. For example, the CORESET group ID may be specific index information defined in the CORESET configuration. That is, the CORESET group may be set / indicated / defined by an index defined in the CORESET configuration for each CORESET. And / or, the CORESET group ID may mean an index / identification information / indicator for distinguishing / identifying between the CORESETs set / associated in each TRP / panel.

[0138] Hereinafter, the CORESET group ID may be replaced with a specific index / specific identification information / specific indicator for distinguishing / identifying the CORESETs set / associated with each TRP / panel. The information may be set / indicated via higher layer signaling (e.g., RRC signaling, MAC-CE, etc.) and / or physical layer signaling (e.g., DCI). For example, PDCCH detection may be set / indicated to be performed for each TRP / panel in units of the corresponding CORESET group, and UCI (e.g., CSI, HARQ-ACK / NACK, SR, etc.) and / or uplink physical channel resources (e.g., PUCCH / PRACH / SRS resources) may be set / indicated to be managed / controlled separately for each TRP / panel in units of the corresponding CORESET group. And / or, HARQ ACK / NACK (process / retransmission) for PDSCH / PUSCH, etc. scheduled for each TRP / panel by CORESET group unit can be managed.

[0139] For example, the upper layer parameter ControlResourceSet IE (information element) may include a CORESET related ID (e.g., controlResourceSetID) / CORESET pool index for CORESET (e.g., CORESETPoolIndex) / time / frequency resource settings of CORESET / TCI information related to CORESET, etc. For example, the index of the CORESET pool (e.g., CORESETPoolIndex) may be set to 0 or 1. In the description above in the present disclosure, a CORESET group may correspond to a CORESET pool, and a CORESET group ID may correspond to a CORESET pool index (e.g., CORESETPoolIndex).

[0140] Additionally, with respect to M-TRP transmission and reception in Rel-17 NR standardization, M-TRP PDCCH / PDSCH SFN transmission, S-DCI-based M-TRP PUSCH repeated transmission, and single PUCCH resource-based M-TRP PUCCH repeated transmission are supported. These transmission techniques repeatedly transmit the same contents (i.e., DCI / UL TB / UCI, etc.) with improved URLLC target for increased reliability. Here, M-TRP PDCCH repeated transmission is performed based on TDM or FDM, M-TRP PDCCH / PDSCH SFN transmission is performed in the same time / frequency / layer, S-DCI-based M-TRP PUSCH repeated transmission is performed based on TDM, and single PUCCH resource-based M-TRP PUCCH repeated transmission is performed based on TDM.

[0141] First, we will look at the S-DCI-based M-TRP PDCCH repetition transmission method.

[0142] In the NR Rel-17 standardization, multiple CORESETs with different TCI states (i.e., different QCL RSs) are configured for the UE for repeated M-TRP PDCCH transmission, and multiple SS (Search Space) sets are configured, each linked to the corresponding CORESETs. The base station can instruct / configure the UE that the SS set connected to one CORESET and the SS set connected to another CORESET are linked for repeated transmission. Through this, the UE can be informed that the PDCCH candidates of the corresponding SS set are being repeatedly transmitted.

[0143] For example, two CORESETs, CORESET 0 and CORESET 1, may be set for a terminal, CORESET 0 and CORESET 1 may be connected to SS set 0 and SS set 1, respectively, and SS set 0 and SS set 1 may be linked. The terminal may recognize that the same DCI has been repeatedly transmitted in the PDCCH candidate of SS set 0 and the PDCCH candidate of SS set 1, and may recognize that a specific PDCCH candidate of SS set 0 and a specific PDCCH candidate of SS set 1 are a pair set for repeatedly transmitting the same DCI based on a specific rule. The two PDCCH candidates are referred to as linked PDCCH candidates, and the terminal may successfully decode the corresponding DCI if it properly receives either of the two PDCCH candidates. However, when receiving a PDCCH candidate of SS set 0, the terminal may use the QCL RS (i.e., DL beam) of the TCI state of COERSET 0 connected to SS set 0, and when receiving a PDCCH candidate of SS set 1, the terminal may use the QCL RS (i.e., DL beam) of the TCI state of COERSET 1 connected to SS set 1. Accordingly, the terminal receives linked PDCCH candidates using different beams.

[0144] Next, we will look at the M-TRP SFN PDCCH / PDSCH transmission method.

[0145] M-TRP is a type of PDCCH repetition transmission, in which multiple TRPs can repeatedly transmit the same DCI through the same time / frequency / DMRS port. This transmission method can be referred to as SFN PDCCH transmission. However, for SFN PDCCH transmission, instead of configuring multiple CORESETs with different TCI states, the base station configures multiple TCI states in a single CORESET. When a terminal receives a PDCCH candidate through an SS set connected to a single CORESET, it can perform channel estimation of the PDCCH DMRS using all of the multiple TCI states and attempt decoding.

[0146] In addition, when the above-described M-TRP PDSCH is repeatedly transmitted, the two TRPs repeatedly transmit the corresponding channel on different resources. However, if the two TRPs use the same resource, that is, if the same channel is repeatedly transmitted through the same frequency / time / layer (i.e., DMRS port), the reliability of the corresponding channel can be improved. In this case, the repeatedly transmitted same channel is not distinguished in terms of resources, so it is received by being combined during transmission (i.e., over the air), and thus can be recognized as a single channel (e.g., a composite channel) from the perspective of the receiving end (e.g., a terminal). For SFN PDSCH transmission, two DL TCI states for PDSCH DMRS reception can be set for the terminal.

[0147] Next, we will look at the S-DCI-based M-TRP PUSCH repetitive transmission scheme.

[0148] In NR Rel-17 standardization, the base station configures two SRS sets for the UE for S-DCI-based M-TRP PUSCH transmission, and each set is used to indicate the UL Tx port and UL beam / QCL information for TRP 1 and TRP 2, respectively. In addition, the base station can indicate SRS resources for each SRS resource set through two SRI fields included in one DCI, and can indicate up to two PC parameter sets. For example, the first SRI field can indicate the SRS resources and PC parameter set defined in SRS resource set 0, and the second SRI field can indicate the SRS resources and PC parameter set defined in SRS resource set 1. The UE can be indicated the UL Tx port, PC parameter set, and UL beam / QCL information for TRP 1 through the first SRI field, and through this, the UE performs PUSCH transmission in the TO corresponding to SRS resource set 0. Similarly, the terminal can be instructed about the UL Tx port, PC parameter set, and UL beam / QCL information for TRP 2 through the second SRI field, and through this, the terminal performs PUSCH transmission in the TO corresponding to SRS resource set 1. In addition to the SRI field, the TPMI, PTRS, and TPC fields can also be instructed for each TRP, so that the existing single field is expanded into two fields. In addition, by introducing a 2-bit SRS resource set indication field, STRP PUSCH repeated transmission can be performed by selecting a specific one of the two SRS sets, and MTRP PUSCH repeated transmission can be performed by selecting both.That is, if the field is 00, 01, SRS set 0, SRS set 1 are indicated respectively, and STRP PUSCH transmission corresponding to each set is performed. If it is 10, (SRS set 0, SRS set 1) is indicated, and MTRP PUSCH transmission is performed in the indicated order of set pairs. That is, set 0 corresponds to the first PUSCH TO. If it is 11, (SRS set 1, SRS set 0) is indicated, and MTRP PUSCH transmission is performed in the indicated order of set pairs. That is, set 1 corresponds to the first PUSCH TO.

[0149] Next, we examine a single PUCCH resource-based M-TRP PUCCH repetition transmission scheme.

[0150] In NR Rel-17 standardization, for M-TRP PUCCH transmission based on a single PUCCH resource, a base station can activate / configure two spatial relation info (if FR1, activate / configure two PC parameter sets) for a single PUCCH resource to a UE. When UL UCI is transmitted through the PUCCH resource, each spatial relation info is used to indicate spatial relation info toward TRP 1 and TRP 2 to the UE. For example, through the value indicated in the first spatial relation info, the UE is instructed with Tx beam / PC parameter(s) toward TRP 1, and the UE performs PUCCH transmission at the TO corresponding to TRP 1 using the information. Similarly, through the value indicated in the second spatial relation info, the UE is instructed with Tx beam / PC parameter(s) toward TRP 2, and the UE performs PUCCH transmission at the TO corresponding to TRP 2 using the information.

[0151] In addition, for M-TRP PUCCH repeated transmission, the configuration method has been improved so that two new spatial relation info can be configured for a PUCCH resource. That is, if PC (power control) parameters such as PLRS, Alpha, P0, and Closed loop index are configured for each spatial relation info, a spatial relation RS can be configured. Consequently, PC information and spatial relation RS information corresponding to two TRPs can be configured through two spatial relation info. Through this, the terminal transmits a UCI (i.e., CSI, ACK / NACK, SR, etc.) PUCCH using the first spatial relation info in the first TO, and transmits the same UCI PUCCH using the second spatial relation info in the second TO. In the present disclosure, a PUCCH resource with two spatial relation info configured is referred to as an M-TRP PUCCH resource, and a PUCCH resource with one spatial relation info configured is referred to as an S-TRP PUCCH resource.

[0152] TCI (transmission configuration indication) state / beam indication

[0153] In addition, in describing the present disclosure, when receiving / transmitting data / DCI / UCI through specific space / time / frequency resources, using (or mapping) a specific TCI state (or TCI) may mean, in the case of DL, estimating a channel from a DMRS using a QCL type and QCL RS indicated by the specific TCI state in the specific space / time / frequency resources, and receiving / demodulating data / DCI / UCI with the estimated channel.

[0154] And, when receiving / transmitting data / DCI / UCI through specific space / time / frequency resources, using (or mapping) a specific TCI state (or TCI) may mean, in the case of UL, transmitting / modulating DMRS and data / UCI using a Tx beam and / or Tx power indicated by a specific TCI state in a specific space / time / frequency resource.

[0155] In addition, the UL TCI state may include Tx beam or Tx power information of the terminal. In addition, the base station may set other parameters, such as spatial relation information, to the terminal instead of the TCI state.

[0156] For example, the UL TCI state can be directly indicated to the UE via the UL grant DCI. Alternatively, the UL TCI state can mean spatial relationship information of SRS resources indicated via the SRI (SRS resource indicator) field of the UL grant DCI. Alternatively, the UL TCI state can mean an open loop (OP) Tx power control parameter linked to a value indicated via the SRI field of the UL grant DCI.

[0157] Here, the OL Tx power control parameters may include, for example, j (index for OP parameter(s) Po and alpha (set of up to 32 parameter values ​​per cell), q_d (index of DL RS resources for path loss (PL) measurement (up to 4 measurements per cell), or / and I (closed-loop power control process index (up to 2 processes per cell)).

[0158] For the convenience of explanation of the present disclosure, it is assumed that two TRPs cooperate with each other to perform transmission / reception operations, but this is not limited thereto. That is, the present disclosure can be expanded to a multi-TRP environment of three or more, and can also be expanded to an environment in which transmission / reception is performed using different panels or beams in the same TRP. A terminal can recognize different TRPs as having different TCI states. When a terminal transmits / receives data / DCI / UCI using TCI state 1, it means that it transmits / receives data / DCI / UCI / from TRP 1 (or to TRP 1).

[0159] TO(Transmission Occasion) refers to each channel transmitted at a different time when multiple channels are TDMed, each channel transmitted on a different frequency / RB when multiple channels are FDMed, and each channel transmitted on a different layer / beam / DMRS port when multiple channels are SDMed. Each TO can be mapped to one TCI state. When the same channel is repeatedly transmitted, complete data / DCI / UCI is transmitted on one TO, and the receiver can receive multiple TOs to increase the reception success rate.

[0160] Single DCI based multi-TB PUSCH / PDSCH scheduling

[0161] In Rel.17 NR, a method for scheduling multiple PUSCH / PDSCH simultaneously with a single DCI is supported in the ultra-high frequency band (beyond 5.26 GHz). For example, multiple TDRAs (=TOs) can be indicated at once through the TDRA field of the PUSCH scheduling DCI, and a different TB is transmitted via the PUSCH for each TO. The FDRA, MCS, TPMI, and SRI values ​​of the DCI are commonly applied to multiple scheduled TBs. In addition, the NDI and RV for each TB are individually indicated through the DCI, and a single HARQ number is indicated, but they sequentially increase in the order of the TOs based on the initial TO.

[0162] STxMP (simultaneous transmission across multiple panels)

[0163] Recently, for the Rel. 18 NR standardization, methods for UEs to simultaneously transmit multiple channels / RSs of the same type or multiple channels / RSs of different types are being discussed. In the case of existing UEs, the operation of transmitting multiple channels / RSs at a time is restricted (e.g., simultaneous transmission of multiple SRS resources of different SRS sets is possible for UL beam measurement, but simultaneous transmission of multiple PUSCHs is not possible). However, in the future, advanced UEs will be able to relax these restrictions and transmit multiple channels or RSs simultaneously using multiple transmission panels. Such UEs are called STxMP UEs. For example, two PUSCHs corresponding to two UL TBs are scheduled on the same RE, and Spatial relation RS 1 and PC parameter Set 1 (i.e., UL TCI state 1) and Spatial relation RS 2 and PC parameter Set 2 (i.e., UL TCI state 2) are set for PUSCH 1 and 2 transmission, respectively. The UE transmits PUSCH 1 using panel 1 corresponding to UL TCI state 1 and simultaneously transmits PUSCH 2 using panel 2 corresponding to UL TCI state 2.

[0164] When a base station schedules a PUSCH through DCI, it can indicate whether the PUSCH will be transmitted as STxMP, as a single panel, or as MTRP PUSCH repetitions. Of course, the UE must have STxMP capability, and the STxMP mode must be enabled in advance, such as through RRC signaling. To achieve this, the existing SRS resource set indication field can be redefined and used, or a new DCI field can be introduced.

[0165] Unified TCI framework

[0166] Figure 8 is a diagram illustrating the concept of the Unified TCI framework introduced in NR Rel. 17. In the Rel. 17 Unified TCI framework, not only the DL TCI state but also the UL TCI state can be indicated through DL DCI (e.g., DCI format 1-1 or 1-2), or only the UL TCI state can be indicated without indicating the DL TCI state through the DL DCI. In this way, Rel. 17 can support dynamic beam update operation through joint DL / UL TCI state indication or separate DL / UL TCI state indication.

[0167] Such dynamic beam update operations may include common beam updates, for example, whereby the base station may instruct the terminal to perform a common beam update operation by instructing it to use one beam for multiple specific channel / RS combinations through DCI and / or MAC-CE.

[0168] Therefore, the methods used for UL beam and power control (PC) configuration in the existing Rel. 15 / 16 can be replaced with the UL TCI state indication method in Rel. 17. In Rel. 17, one UL TCI state can be indicated through the TCI field of DL DCI, and the UL TCI state can be applied to all PUSCHs and all PUCCHs after a certain time called the beam application time, and can be applied to some or all of the indicated SRS resource sets. Specifically, in the case of UL, common beam update can be applied to DG (dynamic grant) / CG (configured grant)-PUSCH, all or a subset of dedicated PUCCH, and additionally, aperiodic CSI-RS for tracking / BM, and SRS can be set as target channels / RS for common beam update.

[0169] Additionally, for DL, Common beam update can be applied to UE-dedicated CORESET and UE-dedicated reception on PDSCH.

[0170] For this common beam applicability, Rel-17 beam indication operation is primarily related to Single-TRP operation.

[0171] In the unified TCI framework, if the number of DL TCI states is expressed as M and the number of UL TCI states is expressed as N, the number of DL / UL TCI states for common beam update of NR Rel. 17 is M=1 / N=1, respectively.

[0172] In NR Rel-18, discussions are underway regarding MIMO standardization, including extensions to the Unified TCI framework configuration (M >1 and / or N >1) and multi-TRP operation through these configurations. Table 6 summarizes the Rel-18 unified TCI framework extensions discussed to date.

[0173] 1. TCI indication1) Existing TCI field in DCI format 1_1 / 1_2 (w, w / o DLA) can indicate multiple joint / DL / UL TCI states2) # of codepoints: up to 83) Combination: J / J, S / S, J / S(X) up to 4 TCI states (in case of S / S) can be indicated in one codepoint4) For M-DCI based MTRP- One joint TCI state can be mapped to a TCI codepoint- DL / UL or a pair of DL / UL TCI states can be mapped to a TCI codepoint5) For S-DCI based MTRP: The existing TCI field in DCI can indicate joint / DL / UL TCI state(s) for one or both of the 2 TRPs in one beam indication instance2.Applicability1) M-DCI based MTRP- TCI field in a DCI associated with one CORESET pool index can indicate joint / DL / UL TCI state(s) specific to the same CORESET pool index valuePDCCH: Apply the indicated TCI state specific to a CORESET pool index to PDCCH on a CORESET that is associated with the same CORESET pool indexPDSCH / PUSCH: Apply the indicated TCI state specific to a CORESET pool index to PDSCH / PUSCH scheduled / activated by PDCCH on a CORESET that is associated with the same CORESET pool indexFor other channels / RSs: FFS- The same configuration / rule (i.e.CORESET determination) used in Rel-17 is reused2) S-DCI based MTRP- Use RRC configurationPDCCH: UE shall apply the TCI state(s) indicated by DCI / MAC-CE to a CORESET or a CORESET group (if CORESET group configuration is supported)PUCCH resource / groupFFS: Alignment on SRS resource set for CB / NCB- Dynamic applicationPDSCH: A new DCI field in DCI format 1_1 / 1_2 that schedules / activates PDSCH reception is used to determine which one or both of the indicated joint / DL TCI states shall be appliedThe presence of the DCI field is configurable by RRCPUSCH: Use an indicator field (could be reusing an existing DCI field or introducing a new DCI field) in DCI format 0_1 / 0_2- PDSCH-CJTIt is supported as a S-DCI based MTRP schemeUp to 2 joint TCI states can be indicated by MAC-CE / DCI and applied to PDSCH-CJTSupport of 1 or 2 indicated joint TCI states is up to UE capabilityFFS: How to apply 2 indicated joint / DL TCI states.

[0174] In particular, regarding the dynamic TCI state application operation related to S-DCI based Multi-TRP (MTRP) PDSCH reception, the agreed upon items at the recent standardization meeting (RAN1#111) are as shown in Table 7.

[0175] 1. AgreementOn unified TCI framework extension for S-DCI based MTRP, a new indicator field is supported as the DCI field in DCI format 1_1 / 1_2 that schedules / activates PDSCH reception to determine which one or both of the indicated joint / DL TCI states shall be applied to the scheduled / activated PDSCH reception- FFS: Detail design of the new indicator field2. AgreementOn unified TCI framework extension for S-DCI based MTRP, a DCI field in DCI format 1_1 / 1_2 that schedules / activates PDSCH reception is used to determine which one or both of the indicated joint / DL TCI states shall be applied to the scheduled / activated PDSCH reception- The presence of the DCI field is configurable by RRC; when the DCI field is not present in DCI format 1_1 / 1_2, the UE shall apply the default indicated joint / DL TCI state(s) to PDSCH receptionFFS: Details on the default indicated joint / DL TCI state(s) to PDSCH reception- FFS: The DCI field is a new indicator field or an existing field (e.g., the existing TCI field)- FFS: regardless the DCI field is present or not present, how to apply the indicated joint / DL TCI state(s) to PDSCH reception if the offset between the reception of the DCI format 1_1 / 1_2 and the corresponding PDSCH reception is less than a thresholdFFS: How to apply the indicated joint / DL TCI state(s) to PDSCH reception scheduled / activated by DCI format 1_0.Above applies for the case where PDSCHs scheduled by the same DCI.

[0176] Meanwhile, in the second Agreement of Table 7, the 'timeDurationforQCL' parameter defined in the existing standard can be used as a threshold for the offset between the DCI format 1_1 / 1_2 and the corresponding PDSCH reception.

[0177] As discussed above, when applying a beam to receive an S-DCI based MTRP PDSCH, a specific field (hereinafter referred to as a new indication field) in the PDSCH scheduling DCI can be added to indicate one or more of the indicated TCI state(s), and the presence or absence of the new indication field can be indicated through an RRC configuration.

[0178] First, referring to Table 6, the relationship between the indicated TCI state(s) through the existing beam indication DCI and the TCI state indication within the DCI scheduling the PDSCH can be examined. For beam indications related to S-DCI based MTRP operation, single / multiple TCI state(s) can be indicated through DCI format 1_1 / 1_2 with or without DL assignment in one beam indication instance. In addition, the TCI state(s) within the latest DCI scheduling the PDSCH will update the existing indicated TCI state after a specific time (i.e. beam application time, BAT) after the ACK for the corresponding DCI. For example, if the existing indicated TCI states = {TCI#1, TCI#2} and the TCI field within the latest DCI indicates {TCI#3, TCI#4}, the indicated TCI states after the BAT will be updated as {TCI#1→TCI#3, TCI#2→TCI#4}. According to the current operation, the number of existing indicated TCI states is also changed by the new TCI state indication. That is, even if the number of existing indicated TCI states is multiple, if the number of TCI states indicated by the new TCI indication is 1, the number of indicated TCI states after BAT becomes 1.In this way, if the number of existing indicated TCI states and the number of TCI states indicated by the TCI field in the latest DCI are different, even if multiple indicated TCI states are applied in the new indication field to be used for PDSCH reception, the number of indicated TCI states will be different before and after BAT, which causes problems in terms of beam applicability. In addition, even if the number of existing indicated TCI states and the number of TCI states indicated by the TCI field in the latest DCI are both 1, there is a limitation that it can only operate as STRP PDSCH only through a single indicated TCI state. In addition, if the new indication field is not present due to RRC configuration, even if the default operation is set to a pre-defined method that uses a specific indicated TCI state or both, it will only operate as either STRP or MTRP PDSCH reception, which causes problems in terms of reduced flexibility in PDSCH scheduling and beam indication.

[0179] Therefore, in this specification, considering the extension of S-DCI based MTRP operation, we propose a method for setting the beam applicability of indicated TCI state(s) to be applied to STRP / MTRP PDSCH reception according to the number of TCI states in the DCI that schedules the introduced new indication field and PDSCH.

[0180] Proposal 1

[0181] In S-DCI based single / multiple TCI state(s) indications according to multiple M and / or N settings, for determining reception beam(s) for PDSCH reception, it operates by setting an indicator to allow maintained beam (i.e. MB) for non-indicated TCI state(s).

[0182] - When MB is allowed, even if a single TCI state is indicated in one beam indication instance, the number of indicated TCI states can always be interpreted as multiple.

[0183] Proposal 1 means that maintained beam operation for indicated TCI states is indicated to dynamically indicate beam applicability for STRP / MTRP PDSCH reception purposes even if the number of existing indicated TCI states and the number of TCI states indicated in the TCI state field in the latest DCI are the same / different. That is, for TCIs that are not indicated in the TCI indication / update of existing indicated TCI state(s) through the latest DCI format 1_1 / 1_2 (with or without DL assignment), the TCI state is not excluded from subsequent beam applicability, but can be interpreted to be used as a maintained / valid / applied beam. If the above MB operation is allowed, for example, when the time point of the latest DCI is t(0), two TCI states {TCI#1, TCI#2} are indicated at time point t(-2), and later, when TCI state {TCI#3} is updated to the 1st indicated TCI state at time point t(-1), the indicated TCI states change to {TCI#1→TCI#3, TCI#2}, and TCI#2 is not indicated and is maintained, that is, the TCI state becomes MB. In this operation, even if the number of TCI states in the subsequent beam indication is 1 after multiple TCI states are indicated, the remaining unindicated TCI state(s) can be maintained and applied to beam applicability, so the number of indicated TCI states can always be interpreted as multiple (e.g., 2 joint TCI states for 2 TRPs).The base station can instruct the terminal through RRC / MAC-CE settings.

[0184] If the MB operation is not allowed, as in Case 2 / 4 of Table 8 below, if the number of indicated TCI states is 1, it may be restricted to use only for STRP PDSCH purposes, and even if there are multiple TCI states in the latest DCI, in order to apply them to MTRP PDSCH reception, they can be applied only to PDSCH receptions after BAT through the new indication field instruction. Conversely, even if there are multiple indicated TCI states, if the number of TCI states in the latest DCI is 1, there is a restriction that multiple TCI states can be applied only to PDSCHs before BAT according to the new indication field instruction.

[0185] Proposal 2

[0186] For STRP / MTRP PDSCH reception according to S-DCI based MTRP extension, a beam update / applicability setting method is proposed according to the presence or absence of a new indication field and the number of TCIs in PDSCH scheduling DCI.

[0187] - Depending on the presence or absence of a new indication field:

[0188] 1) Opt 1-1: When a New indication field is present, one or more of the indicated TCI states can be indicated through the New indication field and used as a PDSCH reception beam for STRP / MTRP purposes.

[0189] 2) Opt 1-2: If the New indication field is absent, one of the indicated TCI states or multiple pre-defined TCI states (depending on whether the number of TCI states in the DCI scheduling the PDSCH is single or multiple) can be used as a PDSCH reception beam for STRP / MTRP purposes. For example, if the New indication field is absent, all of the indicated TCI states can be used for PDSCH reception.

[0190] - Regarding beam application before and after BAT of the above operation:

[0191] 1) Opt 2-1: PDSCH before BAT of latest DCI for PDSCH scheduling can be received based on indicated TCI states (that allow MB).

[0192] 2) Opt 2-2: After the BAT of the latest DCI for PDSCH scheduling, the PDSCH can be received based on the updated TCI states (MB allowed) with the TCI state(s) indicated in the TCI state field in the latest DCI.

[0193] In Proposal 2, considering the MB operation allowance of the above Proposal 1, a beam update / applicability operation according to a new indication field instruction is proposed based on the existing indicated TCI state(s) and the number of TCI states in the DCI that schedules the PDSCH, and the beam update / applicability combinations for the operation are as shown in Table 8 below. {IT#1, MB}, which is an example of indicated TCI states in Case 2 / 4, maintains a non-indicated TCI state as a maintained beam as described in the above Proposal 1, so even if the number of indicated TCI states is 1, the indicated TCI states can be interpreted as plural.

[0194] Table 8 illustrates examples of beam update / applicability combinations based on the number of TCIs in the DCI scheduling the New indication field and PDSCH. It is assumed that the Maintained Beam (MB) operation described above is permitted. In Table 8, "IT" indicates the indicated TCI state, "MB" indicates a maintained beam, and "LT" indicates the TCI in the latest DCI.

[0195] # of indicated TCI states# of TCIs in the latest DCINew indication fieldBehaviorBeam update (after BAT)Beam applicationCase12{IT#1, IT#2}2{LT#1, LT#2}00{IT#1, IT#2}→{LT#1,LT#2}IT#1STRP01IT#2STRP10{IT#1, IT#2}MTRP11{IT#2, IT#1}MTRPX{IT#1, IT#2}MTRPCase21{IT#1, MB}2{LT#1, LT#2}00{IT#1, MB}→{LT#1,LT#2}IT#1STRP01MBSTRP10{IT#1, MB}MTRP11{MB, IT#1}MTRPX{IT#1, MB}MTRPCase32{IT#1, IT#2}1{LT#1}00{IT#1, IT#2}→{LT#1,IT#2}IT#1STRP01{IT#1, IT#2}→{IT#1,LT#1}IT#2STRP10{IT#1, IT#2}→{LT#1,IT#2}{IT#1, IT#2}MTRP11{IT#1, IT#2}→{IT#1,LT#1}{IT#2, IT#1}MTRPX{IT#1, IT#2}→{LT#1,IT#2}IT#1STRPCase41{IT#1, MB}1{LT#1}00{IT#1, MB}→{LT#1,MB}IT#1STRP01{IT#1, MB}→{IT#1,LT#1}MBSTRP10{IT#1, MB}→{LT#1,MB}{IT#1, MB}MTRP11{IT#1, MB}→{IT#1,LT#1}{MB, IT#1}MTRPX{IT#1, MB}→{LT#1,MB}IT#1STRP

[0196] As can be seen in each case of Table 8, a specific one or more of the indicated TCI states are indicated through the 2-bit new indication field to be applied as a beam for the STRP / MTRP PDSCH purpose. For example, in the case of 00 and 01, the first / second TCI state among the 2 indicated TCI states is indicated to be used as the STRP PDSCH reception beam. In the case of 10 and 11, both indicated TCI states are used, but the ordered pair of the corresponding TCI states is used as is or in the reversed order to be applied to the MTRP PDSCH reception beam. Alternatively, the new indication field can be used only for the purpose of TCI state applicability for scheduled PDSCH purposes, and it can operate by indicating in a pre-defined manner through RRC which of the first or second TCI is indicated by the codepoint indicated by the TCI field.

[0197] At this time, if there is no new indication field in each case, even if there are two indicated TCI states by allowing MB, it is not possible to indicate which TCI state(s) to apply and utilize for STRP / MTRP. In such a situation, operation is possible by pre-configuring to use a specific TCI state or both TCI states by default, but it will only operate as STRP or MTRP PDSCH reception. To solve this problem, a dynamic indication method can be used to indicate whether to utilize a single or multiple indicated TCI states depending on the number of TCI states indicated in the TCI field in the latest DCI for PDSCH scheduling. That is, as can be seen in the underlined part in Table 8, for STRP / MTRP PDSCH application, when there is no new indication field, beam application is distinguished according to the number of TCI states in the latest DCI, and the specific single or multiple TCI states indicated at this time can be determined in a pre-defined manner. If there is a new indication field, the applied beam can be determined according to the indication in the corresponding indication field regardless of the number of indicated TCI states.

[0198] In addition, for the above applicability operation, it is necessary to consider the application time for the TCI state(s) indicated by the latest DCI and the PDSCH reception beam determination before / after the corresponding time. That is, the TCIs in the PDSCH scheduling DCI are updated with the indicated TCI state(s) after a specific time (i.e., BAT) after the ACK. Table 8 above assumes that the indicated TCI state(s) are not updated, but if the PDSCH reception is after the BAT, the beam application operation can be performed without changing the ordered pair using the updated TCI after the BAT in each case. For example, in case 2, the updated TCI states after the BAT are {LT#1, LT#2}, and for the PDSCH after the BAT, one or more of the updated TCI states can be applied according to each new indication field to operate. In Case 3, the number of TCIs in the latest DCI is 1 and the number of indicated TCI states is 2. After BAT, the first or second indicated TCI states are updated to LT#1 according to the instructions in the new indication field, and the remaining TCI states that are not indicated are applied to MB to perform beam application operation.

[0199] For the above S-DCI-based PDSCH reception, the PDSCH can be performed before the scheduling DCI is decoded. To this end, the UE can first receive with a specific buffer beam and later, after DCI decoding, decode the previously received PDSCH information based on the information indicated in the DCI. The current Rel-18 unified TCI framework of MTRP extension can extend M / N to 2 each, and DL reception beams can be determined through multiple joint / DL TCI states. In particular, since it is not possible to determine whether the PDSCH is for STRP / MTRP purposes until DCI decoding, the buffer beam determination affects whether PDSCH decoding is performed. Therefore, when a PDSCH for STRP / MTRP purposes is dynamically scheduled through DCI, we propose a method for setting PDSCH buffer beam(s) when the PDSCH is before timeDurationForQCL.

[0200] Proposal 3

[0201] For STRP / MTRP PDSCH reception when M=2 is set according to S-DCI based MTRP extension, a method of setting PDSCH buffer beam(s) based on two (maintained) applied TCI states through existing beam indication is proposed when scheduled PDSCH reception is before timeDurationForQCL.

[0202] (Case 1) Only one of the applied TCI states (e.g. first subset of TCI states, NW configured subset of TCI state(s)) can be set as the (pre-defined) buffer beam.

[0203] - The terminal may not expect the scheduled PDSCH prior to timeDurationForQCL to be used for MTRP purposes. (e.g., for the scheduled PDSCH prior to timeDurationForQCL, the first or second of the two maintained (applied) TCI states is applied.)

[0204] (Case 2) Both applied TCI states can be set to buffer beams.

[0205] - Option 1: The terminal does not expect the scheduled PDSCH prior to timeDurationForQCL to be used for STRP purposes. (e.g., maintain (apply) two TCI states for the scheduled PDSCH prior to timeDurationForQCL)

[0206] - Option 2: After decoding the scheduling DCI, determine whether the PDSCH is for STRP or MTRP purposes by configuring the full-set or sub-set of the TCI state indicated in the TCI state field or new indication field of the DCI.

[0207] 1) If the TCI state field is configured as full-set (e.g., 2 joint TCI states or 4 DL / UL separate TCI states are indicated), it is determined to be an MTRP PDSCH and the PDSCH received with the configured 2 buffer beams is decoded.

[0208] 2) If the TCI state field is composed of a subset (e.g. 1 joint TCI state or 2 DL / UL separate TCI states is / are indicated for TRP1 or TRP2), it is determined to be a STRP PDSCH (for TRP1 or TRP2) and the PDSCH is decoded for one of the information received through 2 buffer beams.

[0209] - At this time, if the new indication field is enabled, it can be determined whether the scheduled PDSCH is a STRP / MTRP PDSCH based on the corresponding codepoint indication value.

[0210] - example

[0211] Codepoint '00': STRP PDSCH for TRP1

[0212] Codepoint '01': STRP PDSCH for TRP2

[0213] Codepoint '10': MTRP PDSCH with {TRP1, TRP2}

[0214] Codepoint '11': MTRP PDSCH with {TRP2, TRP1}

[0215] The buffer beam(s) refers to the default QCL assumption for PDSCH in case the scheduling offset is less than timeDurationForQCL. In this case, even if M=2 is set as the receiving beam for buffering the PDSCH, one of the two existing (maintained) applied TCI states can be selected and performed (case 1). In this case, if the scheduled PDSCH is not for STRP purposes but for MTRP PDSCH after decoding the scheduling DCI, the decoding performance of the PDSCH cannot be guaranteed, and therefore the terminal expects the PDSCH to be STRP only.

[0216] When both applied TCI states are used as buffer beams (case 2), the UE can expect the PDSCH to be MTRP only, as in the previous case (option 1). Alternatively, after completing decoding of the scheduling DCI while receiving with two buffer beams, the UE can determine whether the PDSCH is for STRP or MTRP, and thus decode the PDSCH based on this. A STRP / MTRP distinction can be made based on whether one or two TCI state(s) are indicated in the existing TCI state field in the scheduling DCI. Similarly, the UE can also operate as in the example of Proposal 3 above, based on the indication value of the newly introduced (2-bit) new indication field.

[0217] Figure 9 is a diagram illustrating signal transmission and reception between a terminal and a network in a wireless communication system supporting the Unified TCI framework according to one embodiment. The network may include one or more TRPs.

[0218] Referring to FIG. 9, a terminal can receive configuration information from a network via RRC signaling (905). The configuration information may include information about the field configuration of DCI. For example, the configuration information may include information about whether a specific field (i.e., new indicator field) for dynamic selection of TCI states is provided in the DCI (e.g., tciSelection-PresentInDCI).

[0219] A terminal may receive a first DCI including a TCI field from a network (910). The first DCI may be a scheduling DCI or a non-scheduling DCI (e.g., DCI for beam update without scheduling). Assuming that the TCI field is 3 bits, each of the eight codepoints of the TCI field may be mapped to one or more TCI states. For example, a codepoint mapped to two TCI states may be associated with (i) {1st joint UL and DL TCI state, 2nd joint UL and DL TCI state} or (ii) {1st separate UL TCI state and / or DL ​​TCI state, 2nd separate UL TCI state and / or DL ​​TCI state}. The separate TCI state may individually indicate both the UL TCI state and the DL TCI state, or may indicate only one of the UL TCI state and the DL TCI state. Among the two TCI states mapped to the corresponding codepoint, the first TCI state may be related to a first signal / channel set, and the second TCI state may be related to a second signal / channel set. For example, the first signal / channel set may include at least one of a 1st PDSCH, a 1st PDCCH (CORESET), a 1st CSI-RS, a 1st PUSCH, a 1st (dedciated) PUCCH, and / or a 1st SRS. The second signal / channel set may include at least one of a 2nd PDSCH, a 2nd PDCCH (CORESET), a 2nd CSI-RS, a 2nd PUSCH, a 2nd (dedciated) PUCCH, and / or a 2nd SRS.

[0220] A terminal can maintain two TCI states, and the maintained TCI states can be set / updated based on the TCI field. For example, if a codepoint mapped to one TCI state is indicated through the TCI field, the terminal can update only one of the two TCI states it maintains through the TCI field and maintain the other without updating. For example, if a codepoint mapped to two TCI states is indicated through the TCI field, the terminal can update both TCI states it maintains through the TCI field. Application of the updated TCI state can begin when the BAT time has elapsed since the reception of the first DCI.

[0221] The terminal may receive a second DCI scheduling a PDSCH (915). The terminal may receive a PDSCH based on the second DCI (920).

[0222] When the second DCI is configured to include a specific field (i.e., a new indicator field) via RRC signaling, TCI states to be used for receiving PDSCH may be selected based on the specific field. For example, the first TCI state (STRP1) or the second TCI state (STRP2) among two TCI states maintained by the terminal may be indicated through the specific field, or both the first TCI state and the second TCI state may be indicated together (MTRP). If the BAT time has elapsed from the ACK of the first DCI, the two TCI states that serve as the basis for the specific fields in the second DCI may be updated based on the TCI field of the first DCI, and if the BAT time has not elapsed from the ACK of the first DCI, the two TCI states that serve as the basis for the specific fields in the second DCI may be existing TCI states that have not been updated based on the TCI field of the first DCI.

[0223] If the second DCI does not include a specific field, the terminal can receive the PDSCH based on both TCI states that it maintains.

[0224] Meanwhile, if the reception time of the PDSCH is before the time interval for QCL (quasi-co-location), the terminal can receive the PDSCH by selecting the first TCI state among the two TCI states it maintains.

[0225] Figure 10 illustrates an example implementation of terminal operation according to at least some of the above-described proposals. The present invention is not limited to Figure 10, and the previously described content may be referenced for understanding Figure 10.

[0226] Referring to FIG. 10, a terminal may receive RRC signaling from a network (A05). The RRC signaling may include information regarding whether a specific field related to TCI selection is provided in the DCI.

[0227] The terminal can receive DCI (downlink control information) for downlink scheduling through PDCCH (physical downlink control channel) (A10).

[0228] The terminal can receive a physical downlink shared channel (PDSCH) based on the DCI (A15).

[0229] Depending on RRC signaling (A05), DCI may or may not include certain fields.

[0230] Based on the DCI including a specific field, the terminal can select at least one of a plurality of transmission configuration index (TCI) states maintained in the terminal based on the specific field, and receive the PDSCH based on the selected at least one TCI state.

[0231] Based on the above DCI not including the specific field, the terminal can receive the PDSCH based on all of the plurality of TCI states maintained in the terminal.

[0232] The terminal may select one of the plurality of TCI states to receive the PDSCH based on whether the reception time of the PDSCH is before a time interval for QCL (quasi-co-location). The terminal may select a first TCI state among the plurality of TCI states to receive the PDSCH.

[0233] The number of the plurality of TCI states maintained by the terminal may be 2.

[0234] The terminal may receive another DCI including a TCI field. At least one of a plurality of TCI states maintained in the terminal may be set or changed based on the TCI field. Based on whether a code point of the TCI field is related to one TCI state, the terminal may change one of the plurality of TCI states based on the code point of the TCI field, and maintain the remaining states without change. The application time of the TCI field may be determined based on a beam application time (BAT).

[0235] At least one of the above plurality of TCI states may be associated with multi-TRP (transmission reception point) operation.

[0236] Figure 11 illustrates an implementation example of base station operation according to at least some of the above-described proposals. The present invention is not limited to Figure 11, and the previously described content may be referenced for understanding Figure 11.

[0237] Referring to FIG. 11, the base station may transmit RRC signaling to the terminal (B05). The RRC signaling may include information regarding whether a specific field related to TCI selection is provided in the DCI.

[0238] The base station can transmit DCI (downlink control information) for downlink scheduling to the terminal through PDCCH (physical downlink control channel) (B10).

[0239] The base station can transmit a PDSCH (physical downlink shared channel) to the terminal based on the DCI (B15).

[0240] Depending on RRC signaling (B05), DCI may or may not include certain fields.

[0241] Based on the DCI including a specific field, the base station can select at least one of a plurality of transmission configuration index (TCI) states maintained in the terminal based on the specific field, and transmit the PDSCH based on the selected at least one TCI state.

[0242] Based on the fact that the DCI does not include the specific field, the base station can transmit the PDSCH based on the plurality of TCI states maintained in the terminal.

[0243] The base station may select one of the plurality of TCI states to transmit the PDSCH based on whether the transmission time of the PDSCH is before a time interval for quasi-co-location (QCL). The base station may select a first TCI state among the plurality of TCI states to transmit the PDSCH.

[0244] The number of the plurality of TCI states maintained by the terminal may be 2.

[0245] The base station may transmit another DCI including a TCI field. At least one of a plurality of TCI states maintained in the terminal may be set or changed based on the TCI field. Based on whether a code point of the TCI field is related to one TCI state, one of the plurality of TCI states may be changed based on the code point of the TCI field, and the remaining states may be maintained without change. The application time of the TCI field may be determined based on a beam application time (BAT).

[0246] At least one of the above plurality of TCI states may be associated with multi-TRP (transmission reception point) operation.

[0247] Figure 12 illustrates a communication system (1) to which the present invention can be applied.

[0248] Referring to FIG. 12, a communication system (1) includes a wireless device, a base station, and a network. Here, the wireless device refers to a device that performs communication using a wireless access technology (e.g., 5G NR (New RAT), LTE (Long Term Evolution)) and may be referred to as a communication / wireless / 5G device. Although not limited thereto, the wireless device may include a robot (100a), a vehicle (100b-1, 100b-2), an XR (eXtended Reality) device (100c), a hand-held device (100d), a home appliance (100e), an IoT (Internet of Things) device (100f), and an AI device / server (400). For example, the vehicle may include a vehicle equipped with a wireless communication function, an autonomous vehicle, a vehicle capable of performing vehicle-to-vehicle communication, etc. Here, the vehicle may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone). XR devices include AR (Augmented Reality) / VR (Virtual Reality) / MR (Mixed Reality) devices, and can be implemented in the form of HMD (Head-Mounted Device), HUD (Head-Up Display) installed in a vehicle, television, smartphone, computer, wearable device, home appliance, digital signage, vehicle, robot, etc. Mobile devices can include smartphone, smart pad, wearable device (e.g., smart watch, smart glass), computer (e.g., laptop, etc.), etc. Home appliances can include TV, refrigerator, washing machine, etc. IoT devices can include sensors, smart meters, etc. For example, base stations and networks can also be implemented as wireless devices, and a specific wireless device (200a) can act as a base station / network node to other wireless devices.

[0249] Wireless devices (100a to 100f) can be connected to a network (300) via a base station (200). Artificial Intelligence (AI) technology can be applied to the wireless devices (100a to 100f), and the wireless devices (100a to 100f) can be connected to an AI server (400) via the network (300). The network (300) can be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR) network, etc. The wireless devices (100a to 100f) can communicate with each other via the base station (200) / network (300), but can also communicate directly (e.g., sidelink communication) without going through the base station / network. For example, vehicles (100b-1, 100b-2) can communicate directly (e.g., V2V (Vehicle to Vehicle) / V2X (Vehicle to Everything) communication). In addition, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices (100a to 100f).

[0250] Wireless communication / connection (150a, 150b, 150c) can be established between wireless devices (100a~100f) / base stations (200), and base stations (200) / base stations (200). Here, wireless communication / connection can be achieved through various wireless access technologies (e.g., 5G NR) such as uplink / downlink communication (150a), sidelink communication (150b) (or D2D communication), and communication between base stations (150c) (e.g., relay, IAB (Integrated Access Backhaul). Through wireless communication / connection (150a, 150b, 150c), wireless devices and base stations / wireless devices, and base stations and base stations can transmit / receive wireless signals to each other. For example, wireless communication / connection (150a, 150b, 150c) can transmit / receive signals through various physical channels. To this end, at least some of various configuration information setting processes for transmitting / receiving wireless signals, various signal processing processes (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / demapping, etc.), and resource allocation processes can be performed based on various proposals of the present invention.

[0251] Figure 13 illustrates a wireless device applicable to the present invention.

[0252] Referring to FIG. 13, the first wireless device (100) and the second wireless device (200) can transmit and receive wireless signals through various wireless access technologies (e.g., LTE, NR). Here, {the first wireless device (100), the second wireless device (200)} can correspond to {the wireless device (100x), the base station (200)} and / or {the wireless device (100x), the wireless device (100x)} of FIG. 12.

[0253] A first wireless device (100) includes one or more processors (102) and one or more memories (104), and may further include one or more transceivers (106) and / or one or more antennas (108). The processor (102) controls the memories (104) and / or the transceivers (106), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (102) may process information in the memory (104) to generate first information / signal, and then transmit a wireless signal including the first information / signal via the transceiver (106). In addition, the processor (102) may receive a wireless signal including second information / signal via the transceiver (106), and then store information obtained from signal processing of the second information / signal in the memory (104). The memory (104) may be connected to the processor (102) and may store various information related to the operation of the processor (102). For example, the memory (104) may perform some or all of the processes controlled by the processor (102), or may store software code including commands for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. Here, the processor (102) and the memory (104) may be part of a communication modem / circuit / chip designed to implement a wireless communication technology (e.g., LTE, NR). The transceiver (106) may be connected to the processor (102) and may transmit and / or receive wireless signals via one or more antennas (108). The transceiver (106) may include a transmitter and / or a receiver. The transceiver (106) may be used interchangeably with an RF (Radio Frequency) unit. In the present invention, a wireless device may also mean a communication modem / circuit / chip.

[0254] The second wireless device (200) includes one or more processors (202), one or more memories (204), and may further include one or more transceivers (206) and / or one or more antennas (208). The processor (202) controls the memories (204) and / or the transceivers (206), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (202) may process information in the memory (204) to generate third information / signals, and then transmit a wireless signal including the third information / signals via the transceivers (206). Furthermore, the processor (202) may receive a wireless signal including fourth information / signals via the transceivers (206), and then store information obtained from signal processing of the fourth information / signals in the memory (204). The memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, the memory (204) may perform some or all of the processes controlled by the processor (202), or may store software code including commands for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. Here, the processor (202) and the memory (204) may be part of a communication modem / circuit / chip designed to implement wireless communication technology (e.g., LTE, NR). The transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals via one or more antennas (208). The transceiver (206) may include a transmitter and / or a receiver. The transceiver (206) may be used interchangeably with an RF unit. In the present invention, a wireless device may also mean a communication modem / circuit / chip.

[0255] Hereinafter, the hardware elements of the wireless device (100, 200) will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors (102, 202). For example, one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). One or more processors (102, 202) may generate one or more Protocol Data Units (PDUs) and / or one or more Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors (102, 202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors (102, 202) can generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data or information according to the functions, procedures, proposals and / or methods disclosed herein, and provide the signals to one or more transceivers (106, 206). One or more processors (102, 202) can receive signals (e.g., baseband signals) from one or more transceivers (106, 206) and obtain PDUs, SDUs, messages, control information, data or information according to the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed herein.

[0256] One or more processors (102, 202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. One or more processors (102, 202) may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software configured to perform one or more processors (102, 202) or stored in one or more memories (104, 204) and driven by one or more processors (102, 202). The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software in the form of codes, instructions and / or sets of instructions.

[0257] One or more memories (104, 204) may be coupled to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, codes, instructions, and / or commands. The one or more memories (104, 204) may be configured as ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer-readable storage media, and / or combinations thereof. The one or more memories (104, 204) may be located internally and / or externally to the one or more processors (102, 202). Additionally, the one or more memories (104, 204) may be coupled to the one or more processors (102, 202) via various technologies, such as wired or wireless connections.

[0258] One or more transceivers (106, 206) can transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or flowcharts of this document, to one or more other devices. One or more transceivers (106, 206) can receive user data, control information, wireless signals / channels, etc., as mentioned in the descriptions, functions, procedures, proposals, methods and / or flowcharts of this document, from one or more other devices. For example, one or more transceivers (106, 206) can be connected to one or more processors (102, 202) and can transmit and receive wireless signals. For example, one or more processors (102, 202) can control one or more transceivers (106, 206) to transmit user data, control information, or wireless signals to one or more other devices. Additionally, one or more processors (102, 202) may control one or more transceivers (106, 206) to receive user data, control information, or wireless signals from one or more other devices. Additionally, one or more transceivers (106, 206) may be coupled to one or more antennas (108, 208), and one or more transceivers (106, 206) may be configured to transmit and receive user data, control information, wireless signals / channels, or the like, as referred to in the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed herein, via one or more antennas (108, 208). In this document, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers (106, 206) can convert received user data, control information, wireless signals / channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, wireless signals / channels, etc. using one or more processors (102, 202).One or more transceivers (106, 206) may convert user data, control information, wireless signals / channels, etc. processed by one or more processors (102, 202) from baseband signals to RF band signals. For this purpose, one or more transceivers (106, 206) may include an (analog) oscillator and / or filter.

[0259] Figure 14 illustrates another example of a wireless device applicable to the present invention. The wireless device may be implemented in various forms depending on the use case / service (see Figure 12).

[0260] Referring to FIG. 14, the wireless device (100, 200) corresponds to the wireless device (100, 200) of FIG. 13 and may be composed of various elements, components, units, and / or modules. For example, the wireless device (100, 200) may include a communication unit (110), a control unit (120), a memory unit (130), and an additional element (140). The communication unit may include a communication circuit (112) and a transceiver(s) (114). For example, the communication circuit (112) may include one or more processors (102, 202) and / or one or more memories (104, 204) of FIG. 13. For example, the transceiver(s) (114) may include one or more transceivers (106, 206) and / or one or more antennas (108, 208) of FIG. 13. The control unit (120) is electrically connected to the communication unit (110), the memory unit (130), and the additional elements (140) and controls the overall operation of the wireless device. For example, the control unit (120) may control the electrical / mechanical operation of the wireless device based on the program / code / command / information stored in the memory unit (130). In addition, the control unit (120) may transmit information stored in the memory unit (130) to an external device (e.g., another communication device) via a wireless / wired interface through the communication unit (110), or store information received from an external device (e.g., another communication device) via a wireless / wired interface in the memory unit (130).

[0261] The additional element (140) may be configured in various ways depending on the type of the wireless device. For example, the additional element (140) may include at least one of a power unit / battery, an input / output unit (I / O unit), a driving unit, and a computing unit. Although not limited thereto, the wireless device may be implemented in the form of a robot (Fig. 12, 100a), a vehicle (Fig. 12, 100b-1, 100b-2), an XR device (Fig. 12, 100c), a portable device (Fig. 12, 100d), a home appliance (Fig. 12, 100e), an IoT device (Fig. 12, 100f), a digital broadcasting terminal, a hologram device, a public safety device, an MTC device, a medical device, a fintech device (or a financial device), a security device, a climate / environmental device, an AI server / device (Fig. 12, 400), a base station (Fig. 12, 200), a network node, etc. Wireless devices may be mobile or stationary depending on the use / service.

[0262] In FIG. 14, various elements, components, units / parts, and / or modules within the wireless device (100, 200) may be entirely interconnected via a wired interface, or at least some may be wirelessly connected via a communication unit (110). For example, within the wireless device (100, 200), the control unit (120) and the communication unit (110) may be wired, and the control unit (120) and a first unit (e.g., 130, 140) may be wirelessly connected via the communication unit (110). In addition, each element, component, unit / part, and / or module within the wireless device (100, 200) may further include one or more elements. For example, the control unit (120) may be composed of a set of one or more processors. For example, the control unit (120) may be composed of a set of a communication control processor, an application processor, an electronic control unit (ECU), a graphics processing processor, a memory control processor, etc. As another example, the memory unit (130) may be composed of RAM (Random Access Memory), DRAM (Dynamic RAM), ROM (Read Only Memory), flash memory, volatile memory, non-volatile memory, and / or a combination thereof.

[0263] Figure 15 illustrates a vehicle or autonomous vehicle applicable to the present invention. The vehicle or autonomous vehicle may be implemented as a mobile robot, a car, a train, a manned or unmanned aerial vehicle (AV), a ship, or the like.

[0264] Referring to FIG. 15, a vehicle or autonomous vehicle (100) may include an antenna unit (108), a communication unit (110), a control unit (120), a driving unit (140a), a power supply unit (140b), a sensor unit (140c), and an autonomous driving unit (140d). The antenna unit (108) may be configured as a part of the communication unit (110). Blocks 110 / 130 / 140a to 140d correspond to blocks 110 / 130 / 140 of FIG. 14, respectively.

[0265] The communication unit (110) can transmit and receive signals (e.g., data, control signals, etc.) with external devices such as other vehicles, base stations (e.g., base stations, road side units, etc.), and servers. The control unit (120) can control elements of the vehicle or autonomous vehicle (100) to perform various operations. The control unit (120) can include an ECU (Electronic Control Unit). The drive unit (140a) can drive the vehicle or autonomous vehicle (100) on the ground. The drive unit (140a) can include an engine, a motor, a power train, wheels, brakes, a steering device, etc. The power supply unit (140b) supplies power to the vehicle or autonomous vehicle (100) and can include a wired / wireless charging circuit, a battery, etc. The sensor unit (140c) can obtain vehicle status, surrounding environment information, user information, etc. The sensor unit (140c) may include an IMU (inertial measurement unit) sensor, a collision sensor, a wheel sensor, a speed sensor, an incline sensor, a weight detection sensor, a heading sensor, a position module, a vehicle forward / backward sensor, a battery sensor, a fuel sensor, a tire sensor, a steering sensor, a temperature sensor, a humidity sensor, an ultrasonic sensor, an illuminance sensor, a pedal position sensor, etc. The autonomous driving unit (140d) may implement a technology for maintaining a driving lane, a technology for automatically controlling speed such as adaptive cruise control, a technology for automatically driving along a set path, a technology for automatically setting a path and driving when a destination is set, etc.

[0266] For example, the communication unit (110) can receive map data, traffic information data, etc. from an external server. The autonomous driving unit (140d) can generate an autonomous driving route and driving plan based on the acquired data. The control unit (120) can control the drive unit (140a) so that the vehicle or autonomous vehicle (100) moves along the autonomous driving route according to the driving plan (e.g., speed / direction control). During autonomous driving, the communication unit (110) can irregularly / periodically acquire the latest traffic information data from an external server and can acquire surrounding traffic information data from surrounding vehicles. In addition, during autonomous driving, the sensor unit (140c) can acquire vehicle status and surrounding environment information. The autonomous driving unit (140d) can update the autonomous driving route and driving plan based on newly acquired data / information. The communication unit (110) can transmit information regarding the vehicle location, autonomous driving route, driving plan, etc. to the external server. External servers can predict traffic information data in advance using AI technology or other technologies based on information collected from vehicles or autonomous vehicles, and provide the predicted traffic information data to the vehicles or autonomous vehicles.

[0267] FIG. 16 is a diagram for explaining the DRX (Discontinuous Reception) operation of a terminal according to one embodiment of the present invention.

[0268] A terminal can perform DRX operation while performing the procedures and / or methods described / proposed above. A terminal configured for DRX can reduce power consumption by discontinuously receiving DL signals. DRX can be performed in the RRC (Radio Resource Control)_IDLE state, RRC_INACTIVE state, and RRC_CONNECTED state. In the RRC_IDLE state and RRC_INACTIVE state, DRX is used to discontinuously receive paging signals. Hereinafter, DRX performed in the RRC_CONNECTED state (RRC_CONNECTED DRX) will be described.

[0269] Referring to FIG. 16, a DRX cycle consists of an On Duration and an Opportunity for DRX. The DRX cycle defines the time interval at which the On Duration is periodically repeated. The On Duration represents the time period that the UE monitors to receive a PDCCH. When DRX is configured, the UE performs PDCCH monitoring during the On Duration. If a PDCCH is successfully detected during PDCCH monitoring, the UE starts an inactivity timer and remains awake. On the other hand, if no PDCCH is successfully detected during PDCCH monitoring, the UE enters a sleep state after the On Duration ends. Therefore, when DRX is configured, PDCCH monitoring / reception may be performed discontinuously in the time domain when performing the procedures and / or methods described / proposed above. For example, when DRX is configured, in the present invention, PDCCH reception opportunities (e.g., slots having PDCCH search spaces) may be set discontinuously according to the DRX configuration. On the other hand, when DRX is not configured, PDCCH monitoring / reception may be performed continuously in the time domain when performing the procedures and / or methods described / proposed above. For example, when DRX is not configured, in the present invention, PDCCH reception opportunities (e.g., slots having PDCCH search spaces) may be set continuously. On the other hand, regardless of whether DRX is configured, PDCCH monitoring may be limited in the time interval set as the measurement gap.

[0270] Table 9 shows the process of the terminal related to DRX (RRC_CONNECTED state). Referring to Table 9, DRX configuration information is received through upper layer (e.g., RRC) signaling, and whether DRX is turned on / off is controlled by the DRX command of the MAC layer. When DRX is configured, the terminal can perform PDCCH monitoring discontinuously when performing the procedure and / or method described / proposed in the present invention.

[0271] Type of signalsUE procedure1 st stepRRC signaling(MAC-CellGroupConfig)- Receive DRX configuration information2 nd StepMAC CE((Long) DRX command MAC CE)- Receive DRX command3 rd Step-- Monitor a PDCCH during an on-duration of a DRX cycle

[0272] Here, MAC-CellGroupConfig contains configuration information required to set MAC (Medium Access Control) parameters for a cell group. MAC-CellGroupConfig may also contain configuration information regarding DRX. For example, MAC-CellGroupConfig may contain the following information to define DRX:

[0273] - Value of drx-OnDurationTimer: Defines the length of the starting section of the DRX cycle.

[0274] - Value of drx-InactivityTimer: Defines the length of time period during which the terminal remains awake after a PDCCH opportunity is detected indicating initial UL or DL ​​data.

[0275] - Value of drx-HARQ-RTT-TimerDL: Defines the maximum time interval between the reception of a DL initial transmission and the reception of a DL retransmission.

[0276] - Value of drx-HARQ-RTT-TimerDL: Defines the maximum length of the time interval from when a grant for UL initial transmission is received until a grant for UL retransmission is received.

[0277] - drx-LongCycleStartOffset: Defines the time length and start point of the DRX cycle.

[0278] - drx-ShortCycle (optional): Defines the time length of the short DRX cycle.

[0279] Here, if any one of drx-OnDurationTimer, drx-InactivityTimer, drx-HARQ-RTT-TimerDL, and drx-HARQ-RTT-TimerDL is in operation, the terminal maintains an awake state and performs PDCCH monitoring at every PDCCH opportunity.

[0280] The embodiments described above are combinations of components and features of the present invention in a predetermined form. Each component or feature should be considered optional unless explicitly stated otherwise. Each component or feature may be implemented without being combined with other components or features. Furthermore, it is also possible to form an embodiment of the present invention by combining some components and / or features. The order of operations described in the embodiments of the present invention may be changed. Some components or features of one embodiment may be included in another embodiment or may be replaced with corresponding components or features of another embodiment. It is self-evident that claims that do not have an explicit citation relationship in the patent claims may be combined to form an embodiment or may be incorporated as a new claim through a post-application amendment.

[0281] It will be apparent to those skilled in the art that the present invention can be embodied in other specific forms without departing from the scope of the invention. Therefore, the above detailed description should not be construed as limiting in any respect, but rather as illustrative. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all modifications within the scope of equivalents of the present invention are intended to be included within the scope of the present invention.

[0282] The present invention can be used in a terminal, base station, or other equipment of a wireless mobile communication system.

Claims

1. In a method for a terminal to receive a signal in a wireless communication system, Receiving DCI (downlink control information) for downlink scheduling through PDCCH (physical downlink control channel); and Including receiving a PDSCH (physical downlink shared channel) based on the DCI, Based on the above DCI including a specific field, the terminal: Selecting at least one of a plurality of transmission configuration index (TCI) states maintained in the terminal based on the specific field; and Receive the PDSCH based on at least one selected TCI state, Based on the above DCI not including the above specific field, the terminal: A method for receiving the PDSCH based on all of the plurality of TCI states maintained in the terminal.

2. In paragraph 1, A method further comprising receiving information on whether the DCI includes the specific field via RRC (radio resource control) signaling.

3. In paragraph 1, A method in which the terminal selects one of the plurality of TCI states to receive the PDSCH based on the reception time of the PDSCH being before a time interval for QCL (quasi-co-location).

4. In paragraph 3, A method in which the terminal selects a first TCI state among the plurality of TCI states and receives the PDSCH.

5. In paragraph 1, A method wherein the number of the plurality of TCI states maintained by the terminal is 2.

6. In paragraph 1, Further comprising receiving another DCI containing a TCI field, A method in which at least one of a plurality of TCI states maintained in the terminal is set or changed based on the TCI field.

7. In paragraph 6, A method wherein, based on the code point of the TCI field being related to one TCI state, the terminal changes one of the plurality of TCI states based on the code point of the TCI field, and maintains the rest without change.

8. In paragraph 6, A method in which the application time of the above TCI field is determined based on the beam application time (BAT).

9. In paragraph 1, A method wherein at least one of the plurality of TCI states is associated with a multi-TRP (transmission reception point) operation.

10. A computer-readable recording medium having recorded thereon a program for performing the method described in paragraph 1.

11. In a device for wireless communication, memory that stores commands; and Including a processor that operates by executing the above instructions, The operation of the above processor is as follows: Receiving DCI (downlink control information) for downlink scheduling through PDCCH (physical downlink control channel); and Including receiving a PDSCH (physical downlink shared channel) based on the DCI, Based on the above DCI including a specific field, the processor: Selecting at least one of a plurality of transmission configuration index (TCI) states maintained in the device based on the specific field; and Receive the PDSCH based on at least one selected TCI state, Based on the above DCI not including the above specific field, the processor: A device that receives the PDSCH based on all of the plurality of TCI states maintained in the device.

12. In paragraph 11, Further comprising a transceiver for transmitting or receiving a wireless signal under the control of the processor, The above device is a terminal in a wireless communication system.

13. In paragraph 11, The above device is an ASIC (application specific integrated circuit) or digital signal processing device that controls the terminal.

14. In a method for a base station to transmit a signal in a wireless communication system, Transmitting DCI (downlink control information) for downlink scheduling to the terminal through PDCCH (physical downlink control channel); and Including transmitting a PDSCH (physical downlink shared channel) to the terminal based on the DCI, Based on the above DCI including a specific field, the base station: Selecting at least one of a plurality of transmission configuration index (TCI) states maintained in the terminal based on the specific field; and Transmitting the PDSCH based on the at least one selected TCI state, Based on the above DCI not including the above specific field, the base station: A method for transmitting the PDSCH based on the plurality of TCI states maintained in the terminal.

15. In a base station for wireless communication, memory that stores commands; and Including a processor that operates by executing the above instructions, The operation of the above processor is as follows: Transmitting DCI (downlink control information) for downlink scheduling to the terminal through PDCCH (physical downlink control channel); and Including transmitting a PDSCH (physical downlink shared channel) to the terminal based on the DCI, Based on the above DCI including a specific field, the base station: Selecting at least one of a plurality of transmission configuration index (TCI) states maintained in the terminal based on the specific field; and Transmitting the PDSCH based on the at least one selected TCI state, Based on the above DCI not including the above specific field, the base station: A base station that transmits the PDSCH based on the plurality of TCI states maintained in the terminal.

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