Method and apparatus for transmitting and receiving signals and channels in a wireless communication system

Abstract

A method and an apparatus for transmitting and receiving control information in a wireless communication system are disclosed. A method performed by a terminal in a wireless communication system according to an embodiment of the present disclosure may include receiving, in a first cell, a first DCI indicating a new data indicator (NDI) value and a HARQ process number value, receiving, in the first cell, a group common PDSCH scheduled by the first DCI, receiving, in a second cell, a second DCI indicating the NDI value and the HARQ process number value, and receiving, in the first cell, a terminal dedicated PDSCH scheduled by the second DCI. Here, the terminal dedicated PDSCH may be determined and received as a retransmission of a transport block (TB) of the group common PDSCH based on a preset condition.

Description

[Technical field]

[0001] The present disclosure relates to wireless communication systems, and more particularly, to methods and apparatus for transmitting and receiving group common based signals and channels in wireless communication systems. [Background technology]

[0002] Mobile communication systems were developed to provide voice services while ensuring user activity. However, the scope of mobile communication systems has expanded beyond voice to data services, and currently, resource shortages are occurring due to the explosive increase in traffic, and users are demanding faster services, so there is a demand for more advanced mobile communication systems.

[0003] The requirements for the next generation mobile communication system are to accommodate large and explosive data traffic, dramatically increase the transmission rate per user, accommodate a significantly increased number of connected devices, support very low end-to-end latency, and high energy efficiency.To achieve this, various technologies such as dual connectivity, massive multiple input multiple output (MIMO), in-band full duplex, non-orthogonal multiple access (NOMA), super wideband support, and device networking are being researched. Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present disclosure is to provide a method and apparatus for performing cross-carrier scheduling and / or intra-carrier scheduling for a downlink transmission / reception scheme associated with a multicast broadcast service (MBS).

[0005] A technical problem of the present disclosure is to provide a method and apparatus for overriding multicast semi-persistent scheduling (SPS) transmission with point to point (PTP) retransmission and / or unicast transmission.

[0006] The technical problems to be achieved by the present disclosure are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by a person having ordinary skill in the art to which the present disclosure pertains from the following description. [Means for solving the problem]

[0007] A method performed by a terminal in a wireless communication system according to an embodiment of the present disclosure may include receiving, in a first cell, downlink control information (DCI) indicating a new data indicator (NDI) value and a hybrid automatic repeat request (HARQ) process number value, receiving, in the first cell, a group-common physical downlink shared channel (PDSCH) scheduled by the first DCI, receiving, in a second cell, a second DCI indicating the NDI value and the HARQ process number value, and receiving, in the first cell, a terminal-dedicated PDSCH scheduled by the second DCI. Here, the terminal-dedicated PDSCH may be determined and received as a retransmission of a transport block (TB) of the group-common PDSCH based on a preset condition.

[0008] A method performed by a network device in a wireless communication system according to a further aspect of the present disclosure may include transmitting, in a first cell, a first DCI indicating an NDI value and a HARQ process number value, transmitting, in the first cell, a group-common PDSCH scheduled by the first DCI, transmitting, in a second cell, a second DCI indicating the NDI value and the HARQ process number value, and transmitting, in the first cell, a terminal-dedicated PDSCH scheduled by the second DCI, wherein the terminal-dedicated PDSCH may be transmitted as a retransmission of a transport block of the group-common PDSCH based on a preset condition. Effect of the Invention

[0009] According to an embodiment of the present disclosure, cross-carrier scheduling / intra-carrier scheduling can be supported by a scheduled cell or a scheduling cell for PTM (point to multipoint) transmission and PTP (point to point) retransmission, and an advantage is that a base station can flexibly schedule group common transmission in a CA (carrier aggregation) situation.

[0010] According to the embodiment of the present disclosure, it is possible to clarify the priority of PTP retransmission / unicast transmission for the same or different services, and to enable the base station to override the multicast SPS.

[0011] The effects obtained from the present disclosure are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by a person having ordinary skill in the art to which the present disclosure pertains from the following description. [Brief description of the drawings]

[0012] The accompanying drawings, which are included as part of the detailed description to aid in understanding the present disclosure, provide examples of the present disclosure and, together with the detailed description, explain the technical features of the present disclosure.

[0013] [Figure 1] 1 illustrates the structure of a wireless communication system to which the present disclosure can be applied.

[0014] [Diagram 2] 1 illustrates a frame structure in a wireless communication system to which the present disclosure can be applied.

[0015] [Diagram 3] 1 illustrates an example of a resource grid in a wireless communication system to which the present disclosure can be applied.

[0016] [Figure 4] 1 illustrates an example of a physical resource block in a wireless communication system to which the present disclosure can be applied.

[0017] [Diagram 5] 1 illustrates an example of a slot structure in a wireless communication system to which the present disclosure can be applied.

[0018] [Figure 6] 1 illustrates examples of physical channels used in a wireless communication system to which the present disclosure can be applied, and a general signal transmission / reception method using the physical channels.

[0019] [Figure 7] 1 illustrates a multiple TRP transmission method in a wireless communication system to which the present disclosure can be applied.

[0020] [Figure 8] 1 illustrates a HARQ-ACK process for downlink data in a wireless communication system to which the present disclosure can be applied.

[0021] [Figure 9] 4 illustrates a HARQ-ACK transmission and reception procedure for a multicast PDSCH according to one embodiment of the present disclosure.

[0022] [Figure 10] 1 illustrates an example of transmission and reception of a group common channel and a corresponding HARQ-ACK report in a wireless communication system to which the present disclosure can be applied.

[0023] [Figure 11] 11 is a diagram illustrating an example of the operation of a terminal in relation to group common transmission and reception according to an embodiment of the present disclosure.

[0024] [Figure 12] 11 is a diagram illustrating the operation of a network device in relation to group common transmission and reception according to an embodiment of the present disclosure.

[0025] [Figure 13] 1 illustrates an example of cross-carrier scheduling for PTP retransmission to which an embodiment of the present disclosure can be applied.

[0026] [Figure 14] 1 illustrates an example of self-scheduling for PTP retransmission to which an embodiment of the present disclosure can be applied.

[0027] [Figure 15] 13 illustrates another example of cross-carrier scheduling for PTP retransmission to which an embodiment of the present disclosure can be applied.

[0028] [Figure 16] 1 illustrates transmission and reception of unicast and multicast channels and a corresponding HARQ-ACK report in a wireless communication system to which the present disclosure can be applied.

[0029] [Figure 17] 1 illustrates an example of transmission and reception of unicast channels and multicast channels using FDM in a wireless communication system to which the present disclosure can be applied.

[0030] [Figure 18] FIG. 2 is a block diagram of a wireless communication device according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description disclosed below together with the accompanying drawings is intended to describe exemplary embodiments of the present disclosure, and is not intended to show the only embodiment in which the present disclosure can be implemented. The detailed description below includes specific details to provide a complete understanding of the present disclosure. However, it is understood by those skilled in the art that the present disclosure can be implemented without such specific details.

[0032] In some cases, in order to avoid obscuring the concepts of the present disclosure, known structures and devices may be omitted or may be shown in the form of a block diagram focusing on the core functions of each structure and device.

[0033] In this disclosure, when an element is "coupled," "coupled," or "connected" to another element, this can include a direct connection as well as an indirect connection where there is still another element between them. Also, in this disclosure, the terms "including" or "having" specify the presence of a stated feature, step, operation, element, and / or component, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0034] In this disclosure, terms such as "first" and "second" are used only to distinguish one component from another component, and are not used to limit the components, and do not limit the order or importance of the components unless otherwise specified. Therefore, within the scope of this disclosure, a first component in one embodiment may be referred to as a second component in another embodiment, and similarly, a second component in one embodiment may be referred to as a first component in another embodiment.

[0035] The terms used in this disclosure are for the purpose of describing particular embodiments and are not intended to limit the scope of the claims. As used in the description of the embodiments and the appended claims, the singular form is intended to include the plural form unless the context dictates otherwise. The term "and / or" used in this disclosure means that one of the associated listed items may be included, or any and all possible combinations of two or more of them. Also, in this disclosure, " / " between words has the same meaning as "and / or" unless otherwise specified.

[0036] The present disclosure is described with respect to a wireless communication network or wireless communication system, and operations performed in the wireless communication network may be performed in a process in which a device (e.g., a base station) that manages the wireless communication network controls the network and transmits or receives signals, or in a process in which a terminal coupled to the wireless network transmits or receives signals to or between the network.

[0037] In this disclosure, transmitting or receiving a channel includes transmitting or receiving information or signals on that channel. For example, transmitting a control channel means transmitting control information or signals on the control channel. Similarly, transmitting a data channel means transmitting data information or signals on the data channel.

[0038] In the following, downlink (DL) means communication from a base station to a terminal, and uplink (UL) means communication from a terminal to a base station. In the downlink, a transmitter may be a part of the base station, and a receiver may be a part of the terminal. In the uplink, a transmitter may be a part of the terminal, and a receiver may be a part of the base station. The base station may be expressed as a first communication device, and the terminal may be expressed as a second communication device. A base station (BS) may be replaced with terms such as a fixed station, Node B, eNB (evolved-NodeB), gNB (Next Generation NodeB), BTS (base transceiver system), access point (AP), network (5G network), AI (Artificial Intelligence) system / module, RSU (road side unit), robot, drone (UAV: Unmanned Aerial Vehicle), AR (Augmented Reality) device, VR (Virtual Reality) device, etc. In addition, a terminal may be fixed or mobile, and may be replaced with terms such as User Equipment (UE), Mobile Station (MS), user terminal (UT), Mobile Subscriber Station (MSS), Subscriber Station (SS), Advanced Mobile Station (AMS), Wireless terminal (WT), Machine-Type Communication (MTC) device, Machine-to-Machine (M2M) device, Device-to-Device (D2D) device, vehicle, road side unit (RSU), robot, Artificial Intelligence (AI) module, drone (UAV: Unmanned Aerial Vehicle), Augmented Reality (AR) device, Virtual Reality (VR) device, etc.

[0039] The following technologies may be used for various wireless access systems such as CDMA, FDMA, TDMA, OFDMA, SC-FDMA, etc. CDMA may be implemented by radio technologies such as Universal Terrestrial Radio Access (UTRA) and CDMA2000. TDMA may be implemented by radio technologies such as Global System for Mobile communications (GSM) / General Packet Radio Service (GPRS) / Enhanced Data Rates for GSM Evolution (EDGE). OFDMA may be implemented by radio technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, Evolved UTRA (E-UTRA), etc. UTRA is part of the Universal Mobile Telecommunications System (UMTS). 3GPP (registered trademark) (3rd Generation Partnership Project) LTE (Long Term Evolution) is a part of E-UMTS (Evolved UMTS) that uses E-UTRA, and LTE-A (Advanced) / LTE-A pro 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 / LTE-A pro.

[0040] For clarity of explanation, the following description will be based on a 3GPP communication system (e.g., LTE-A, NR), but the technical idea of ​​the present disclosure is not limited thereto. LTE refers to technology after 3GPP TS (Technical Specification) 36.xxx Release 8. In detail, LTE technology after 3GPP TS 36.xxx Release 10 is called LTE-A, and LTE technology after 3GPP TS 36.xxx Release 13 is called LTE-A pro. 3GPP NR refers to technology after TS 38.xxx Release 15. LTE / NR may be called a 3GPP system. "xxx" refers to a standard document detail number. LTE / NR may be called a 3GPP system. For background technology, terms, abbreviations, etc. used in the description of the present disclosure, reference may be made to matters described in standard documents published before the present disclosure. For example, the following documents may be referenced.

[0041] In 3GPP LTE, reference can be made to TS 36.211 (physical channels and modulation), TS 36.212 (multiplexing and channel coding), TS 36.213 (physical layer procedures), TS 36.300 (general description), and TS 36.331 (radio resource control).

[0042] For 3GPP NR, reference can be made to TS 38.211 (Physical channels and modulation), TS 38.212 (Multiplexing and channel coding), TS 38.213 (Physical layer procedures for control), TS 38.214 (Physical layer procedures for data), TS 38.300 (General description of NR and NG-RAN (New Generation-Radio Access Network)), and TS 38.331 (Radio resource control protocol standard).

[0043] The following terminology abbreviations may be used in this disclosure:

[0044] - BM: Beam management

[0045] - CQI: channel quality indicator

[0046] - CRI: channel state information-reference signal resource indicator

[0047] - CSI: channel state information

[0048] - CSI-IM: channel state information-interference measurement

[0049] - CSI-RS: Channel state information-reference signal

[0050] - DMRS: Demodulation Reference Signal

[0051] - FDM: Frequency division multiplexing

[0052] - FFT: Fast Fourier transform

[0053] - IFDMA: Interleaved frequency division multiple access

[0054] - IFFT: inverse fast Fourier transform

[0055] - L1-RSRP: Layer 1 reference signal received power

[0056] - L1-RSRQ: Layer 1 reference signal received quality

[0057] - MAC: medium access control

[0058] - NZP: non-zero power

[0059] - OFDM: Orthogonal frequency division multiplexing

[0060] - PDCCH: physical downlink control channel

[0061] - PDSCH: physical downlink shared channel

[0062] - PMI: Precoding matrix indicator

[0063] - RE: resource element

[0064] - RI: Rank indicator

[0065] - RRC: Radio resource control

[0066] - RSSI: received signal strength indicator

[0067] - Rx: Reception

[0068] - QCL: quasi co-location

[0069] - SINR: signal to interference and noise ratio

[0070] - SSB (or SS / PBCH block): Synchronization signal block (including primary synchronization signal (PSS), secondary synchronization signal (SSS) and physical broadcast channel (PBCH))

[0071] - TDM: time division multiplexing

[0072] - TRP: transmission and reception point

[0073] - TRS: Tracking reference signal

[0074] - Tx: transmission

[0075] - UE: User Equipment

[0076] - ZP: Zero power

[0077] System in general

[0078] As more communication devices require larger communication capacity, the need for improved mobile broadband communication compared to existing radio access technologies (RATs) is emerging. Massive Machine Type Communications (MTC), which connects a large number of devices and objects to provide various services anytime and anywhere, is also one of the major issues to be considered in next-generation communication. In addition, communication system design considering reliability and latency-sensitive services / terminals is also being discussed. Thus, the introduction of next-generation RATs considering eMBB (enhanced mobile broadband communication), Mmtc (massive MTC), URLLC (Ultra-Reliable and Low Latency Communication), etc. is being discussed, and for convenience in this disclosure, the technology is referred to as NR. NR is an expression representing an example of 5G RAT.

[0079] New RAT systems including NR use an OFDM transmission scheme or a similar transmission scheme. The new RAT system may follow OFDM parameters different from those of LTE. Alternatively, the new RAT system may follow the existing LTE / LTE-A numerology but support a larger system bandwidth (e.g., 100 MHz). Alternatively, one cell may support multiple numerologies. That is, terminals operating with different numerologies may coexist in one cell.

[0080] A numerology corresponds to a subcarrier spacing in the frequency domain. Different numerologies can be defined by scaling the reference subcarrier spacing by an integer N.

[0081] FIG. 1 illustrates the structure of a wireless communication system to which the present disclosure can be applied.

[0082] Referring to FIG. 1, the NG-RAN is composed of gNBs that provide an NG-Radio Access (NG-RA) user plane (i.e., new access stratum (AS) sublayer / Packet Data Convergence Protocol (PDCP) / Radio Link Control (RLC) / MAC / PHY) and control plane (RRC) protocol termination for UEs. The gNBs are interconnected via an Xn interface. The gNBs are also connected to a New Generation Core (NGC) via an NG interface. More specifically, the gNBs are connected to an Access and Mobility Management Function (AMF) via an N2 interface and to a User Plane Function (UPF) via an N3 interface.

[0083] FIG. 2 illustrates a frame structure in a wireless communication system to which the present disclosure can be applied.

[0084] The NR system can support multiple numerologies, where the numerology may be defined by subcarrier spacing and cyclic prefix (CP) overhead. In this case, the multiple subcarrier spacing may be derived by scaling the base (reference) subcarrier spacing by an integer N (or μ). In addition, the numerology used may be selected independently of the frequency band, even if it is assumed that very low subcarrier spacing is not utilized at very high carrier frequencies. In addition, various frame structures with multiple numerologies may be supported in the NR system.

[0085] The following describes OFDM numerologies and frame structures that can be considered in the NR system. A number of OFDM numerologies supported in the NR system may be defined as shown in Table 1 below.

[0086] [Table 1]

[0087] NR supports multiple numerologies (or subcarrier spacing (SCS)) to support various 5G services, such as 15kHz SCS to support wide areas in traditional cellular bands, 30kHz / 60kHz SCS to support dense-urban, lower latency, and wider carrier bandwidth, and 60kHz or higher SCS to support bandwidths larger than 24.25GHz to overcome phase noise.

[0088] The NR frequency band is defined as two types of frequency ranges (FR1, FR2). FR1 and FR2 may be configured as shown in Table 2 below. FR2 may also refer to millimeter wave (mmW).

[0089] [Table 2]

[0090] In relation to the frame structure in the NR system, the sizes of the various fields in the time domain are T c =1 / (Δf max N f ) where Δf max =480 10 3 Hz and Nf = 4096. Downlink and uplink transmissions are f =1 / (Δf max N f / 100)·T c The radio frame is organized into radio frames each having a duration of T sf =(Δf max N f / 1000)·T c In this case, there may be one set of frames for the uplink and one set of frames for the downlink. Also, the transmission from the terminal in the uplink frame number i starts T TA =(N TA +N TA,offset )T c For a subcarrier spacing configuration μ, a slot is allocated within a subframe. s μ ∈{0,...,N slot subframe,μ -1}, and n s,f μ ∈{0,...,N slot frame,μ The slots are numbered in increasing order {N -1}. symb slot It consists of N consecutive OFDM symbols. symb slot is determined by the CP. s μ The start of OFDM symbol n s μ N symb slotNot all terminals can transmit and receive at the same time, which means that not all OFDM symbols in a downlink slot or uplink slot can be used.

[0091] Table 3 shows the number of OFDM symbols per slot (N symb slot ), the number of slots per radio frame (N slot frame,μ ), the number of slots per subframe (N slot subframe,μ ), and Table 4 shows the number of OFDM symbols per slot, the number of slots per radio frame, and the number of slots per subframe in the extended CP.

[0092] [Table 3]

[0093] [Table 4]

[0094] Figure 2 is an example when μ=2 (SCS is 60 kHz), and referring to Table 3, one subframe can include 4 slots. One subframe={1, 2, 4} slots shown in Figure 2 is an example, and the number of slots that can be included in one subframe is defined as shown in Table 3 or Table 4. Also, a mini-slot can include 2, 4, or 7 symbols, or more or less symbols.

[0095] In relation to physical resources in an NR system, antenna ports, resource grids, resource elements, resource blocks, carrier parts, etc. may be considered. Hereinafter, the physical resources that can be considered in an NR system will be specifically described.

[0096] First, with respect to antenna ports, the antenna ports are defined such that the channel on which a symbol on an antenna port is carried can be inferred from the channel on which another symbol on the same antenna port is carried. If the large-scale properties of the channel on which a symbol on one antenna port is carried can be inferred from the channel on which a symbol on the other antenna port is carried, the two antenna ports are said to be in a quasi co-located (QC / QCL) relationship. Here, the large-scale properties include one or more of delay spread, Doppler spread, frequency shift, average received power, and received timing.

[0097] FIG. 3 illustrates a resource grid in a wireless communication system to which the present disclosure can be applied.

[0098] Referring to FIG. 3, the resource grid is divided into N RB μ N sc RB Each subframe consists of 14.2 subcarriers. μ In the present embodiment, the OFDM symbol is used as an example, but is not limited to, an OFDM symbol. RBμ N sc RB One or more resource grids consisting of subcarriers and two μ N symb (μ) OFDM symbols, where N RB μ ≦N RB max,μ The above N RB max,μ represents the maximum transmission bandwidth, which may vary between uplink and downlink as well as numerology. In this case, one resource grid may be set for μ and antenna port p. Each element of the resource grid for μ and antenna port p is called a resource element and is represented by an index pair (k, JPEG2025503595000006.jpg53), where k=0,...,N RB μ N sc RB -1 is the index in the frequency domain, JPEG2025503595000007.jpg53=0,...,2 μ N symb (μ) −1 represents the position of the symbol within a subframe. When referring to resource elements in a slot, the index pair (k, l) is used, where l=0,...,N symb μ μ and the resource element (k, JPEG2025503595000008.jpg54) is a complex value JPEG2025503595000009.jpg811. If there is no risk of confusion or if a specific antenna port or numerology is not specified, the indexes p and μ may be dropped, so that the complex value is JPEG2025503595000010.jpg912 or JPEG2025503595000011.jpg912. Also, a resource block (RB) is N sc RB = 12 consecutive subcarriers.

[0099] Point A serves as a common reference point for the resource block grid and is obtained as follows:

[0100] - offsetToPointA for the primary cell (PCell) downlink indicates the frequency offset between point A and the lowest subcarrier of the lowest resource block that overlaps with the SS / PBCH block used by the terminal for initial cell selection. It is expressed in resource block units assuming 15 kHz subcarrier spacing for FR1 and 60 kHz subcarrier spacing for FR2.

[0101] - absoluteFrequencyPointA indicates the frequency-location of point A expressed as in ARFCN (absolute radio-frequency channel number).

[0102] Common resource blocks are numbered from 0 upwards in the frequency domain for a subcarrier spacing setting μ. The center of subcarrier 0 of common resource block 0 for a subcarrier spacing setting μ coincides with 'point A'. Common resource block number n CRB μ The relationship between k, l and the resource element (k, l) for the subcarrier spacing setting μ is given by the following Equation 1.

[0103]

number

[0104] In Equation 1, k is defined relative to point A such that k=0 corresponds to the subcarrier centered at point A. A physical resource block is a number ranging from 0 to N within a bandwidth part (BWP). BWP,i size,μ The numbering is from -1 to i, where i is the number of the BWP. PRB and common resource block n CRB The relationship between is given by Equation 2 below.

[0105]

number

[0106] N BWP,i start,μ is the common resource block where the BWP starts relative to common resource block 0.

[0107] Fig. 4 illustrates a physical resource block in a wireless communication system to which the present disclosure can be applied, and Fig. 5 illustrates a slot structure in a wireless communication system to which the present disclosure can be applied.

[0108] 4 and 5, a slot includes a number of symbols in the time domain. For example, in the general CP, one slot includes seven symbols, while in the extended CP, one slot includes six symbols.

[0109] A carrier includes 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) resource blocks in the frequency domain and may correspond to one numerology (e.g., SCS, CP length, etc.). A carrier may include up to N (e.g., 5) BWPs. Data communication is performed in the activated BWPs, and only one BWP may be activated for one terminal. Each element in the resource grid is called a resource element (RE), and one complex symbol may be mapped to it.

[0110] The NR system may support up to 400 MHz per component carrier (CC). If a terminal operating in such a wideband CC always operates with the radio frequency (RF) chip for the entire CC turned on, the terminal battery consumption may increase. Alternatively, considering various use cases (e.g., eMBB, URLLC, Mmtc, V2X, etc.) operating in one wideband CC, different numerologies (e.g., subcarrier spacing, etc.) may be supported for each frequency band in the CC. Alternatively, the capability for maximum bandwidth may differ for each terminal. In consideration of this, the base station may instruct the terminal to operate only in a part of the bandwidth rather than the entire bandwidth of the wideband CC, and the part of the bandwidth is defined as a bandwidth part (BWP) for convenience. The BWP may be composed of continuous RBs on the frequency axis and may correspond to one numerology (e.g., subcarrier spacing, CP length, slot / minislot interval).

[0111] Meanwhile, the base station can set multiple BWPs even within one CC set in the terminal. For example, a BWP occupying a relatively small frequency region can be set in the PDCCH monitoring slot, and the PDSCH indicated by the PDCCH can be scheduled on a larger BWP. Alternatively, when UEs are concentrated in a specific BWP, other BWPs can be set in some terminals for load balancing. Alternatively, in consideration of frequency domain inter-cell interference cancellation between adjacent cells, some spectrums of the entire bandwidth can be excluded and both BWPs can be set in the same slot. That is, the base station can set at least one DL / UL BWP in the terminal associated with the wideband CC. The base station can activate at least one DL / UL BWP set at a specific time (by L1 signaling, MAC CE (Control Element), RRC signaling, etc.). Also, the base station may instruct switching to another configured DL / UL BWP (by L1 signaling, MAC CE, RRC signaling, etc.). Or, the base station may switch to a predetermined DL / UL BWP when a timer value expires on a timer basis. In this case, the activated DL / UL BWP is defined as an active DL / UL BWP. However, in a situation where the UE is performing an initial access process or before an RRC connection is set up, the UE may not be able to receive the configuration for the DL / UL BWP. In such a situation, the DL / UL BWP assumed by the UE is defined as an initially active DL / UL BWP.

[0112] FIG. 6 illustrates examples of physical channels used in a wireless communication system to which the present disclosure can be applied, and a general signal transmission / reception method using the physical channels.

[0113] In a wireless communication system, a terminal receives information from a base station through a downlink, and transmits information to the base station through an uplink. 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 / purpose of the information they transmit and receive.

[0114] When the terminal is powered on or newly enters a cell, the terminal performs an initial cell search such as synchronizing with the base station (S601). To this end, the terminal receives a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) from the base station to synchronize with the base station and obtain information such as a cell identifier (ID). After that, the terminal receives a physical broadcast channel (PBCH) from the base station to obtain broadcast information within the cell. Meanwhile, the terminal can receive a downlink reference signal (DL RS) during the initial cell search stage to check the downlink channel state.

[0115] After completing the initial cell search, the terminal receives a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) based on the information carried on the PDCCH, and can obtain more specific system information (S602).

[0116] Meanwhile, when the terminal first connects to the base station or has no radio resources for signal transmission, the terminal can perform a random access procedure (RACH) to the base station (steps S603 to S606). To this end, the terminal can transmit a specific sequence as a preamble on a physical random access channel (PRACH) (S603 and S605) and receive a response message to the preamble on a PDCCH and a corresponding PDSCH (S604 and S606). In the case of a contention-based RACH, the terminal can also perform a contention resolution procedure.

[0117] After performing the above-mentioned procedures, the terminal can then perform PDCCH / PDSCH reception (S607) and Physical Uplink Shared Channel (PUSCH) / Physical Uplink Control Channel (PUCCH) transmission (S608) as a general uplink / downlink signal transmission procedure. In particular, the terminal receives Downlink Control Information (DCI) through the PDCCH. Here, the DCI includes control information such as resource allocation information for the terminal, and has different formats depending on its purpose.

[0118] Meanwhile, control information that a terminal transmits to a base station in an uplink or that the terminal receives from a base station includes downlink / uplink ACK / NACK (Acknowledgement / Non-Acknowledgement) signals, CQI (Channel Quality Indicator), PMI (Precoding Matrix Indicator), RI (Rank Indicator), etc. In a 3GPP LTE system, a terminal can transmit the above-mentioned control information such as CQI / PMI / RI in a PUSCH and / or a PUCCH.

[0119] Table 5 shows an example of a DCI format in an NR system.

[0120] [Table 5]

[0121] Referring to Table 5, DCI formats 0_0, 0_1, and 0_2 may include resource information related to PUSCH scheduling (e.g., UL / SUL (Supplementary UL), frequency resource allocation, time resource allocation, frequency hopping, etc.), transport block (TB) related information (e.g., MCS (Modulation Coding and Scheme), NDI (New Data Indicator), RV (Redundancy Version), etc.), HARQ (Hybrid- Automatic Repeat and request) related information (e.g., process number, DAI (Downlink Assignment Index), PDSCH-HARQ feedback timing, etc.), multiple antenna related information (e.g., DMRS sequence initialization information, antenna port, CSI request, etc.), and power control information (e.g., PUSCH power control, etc.), and the control information included in each of the DCI formats may be predefined.

[0122] DCI format 0_0 is used for scheduling PUSCH in one cell. Information included in DCI format 0_0 is CRC (cyclic redundancy check) scrambled by C-RNTI (Cell RNTI: Cell Radio Network Temporary Identifier), CS-RNTI (Configured Scheduling RNTI), or MCS-C-RNTI (Modulation Coding Scheme Cell RNTI) and transmitted.

[0123] DCI format 0_1 ​​is used to indicate to a terminal the scheduling of one or more PUSCHs in one cell or downlink feedback information of a configured grant (CG). Information included in DCI format 0_1 ​​is CRC scrambled by C-RNTI, CS-RNTI, SP-CSI-RNTI (Semi-Persistent CSI RNTI), or MCS-C-RNTI and transmitted.

[0124] DCI format 0_2 is used for PUSCH scheduling in one cell. Information included in DCI format 0_2 is CRC scrambled by C-RNTI, CS-RNTI, SP-CSI-RNTI, or MCS-C-RNTI and transmitted.

[0125] Next, DCI formats 1_0, 1_1, and 1_2 may include resource information related to PDSCH scheduling (e.g., frequency resource allocation, time resource allocation, VRB (virtual resource block)-PRB (physical resource block) mapping, etc.), transmission block (TB) related information (e.g., MCS, NDI, RV, etc.), HARQ related information (e.g., process number, DAI, PDSCH-HARQ feedback timing, etc.), multiple antenna related information (e.g., antenna port, TCI (transmission configuration indicator), SRS (sounding reference signal) request, etc.), PUCCH related information (e.g., PUCCH power control, PUCCH resource indicator, etc.), and the control information included in each of the DCI formats may be pre-defined.

[0126] DCI format 1_0 is used for PDSCH scheduling in one DL cell. Information included in DCI format 1_0 is CRC scrambled by C-RNTI, CS-RNTI, or MCS-C-RNTI and transmitted.

[0127] DCI format 1_1 is used for scheduling the PDSCH in one cell. Information included in DCI format 1_1 is CRC scrambled by the C-RNTI, CS-RNTI, or MCS-C-RNTI and transmitted.

[0128] DCI format 1_2 is used for scheduling the PDSCH in one cell. Information included in DCI format 1_2 is CRC scrambled by the C-RNTI, CS-RNTI, or MCS-C-RNTI and transmitted.

[0129] Quasi-Co Location (QCL)

[0130] Antenna ports are defined such that the channel on which symbols on an antenna port are carried can be inferred from the channel on which other symbols on the same antenna port are carried. If the properties of the channel on which symbols on one antenna port are carried can be inferred from the channel on which symbols on the other antenna port are carried, then two antenna ports are said to be in a quasi co-located (QC / QCL) relationship.

[0131] Here, the channel characteristics include one or more of delay spread, Doppler spread, frequency / Doppler shift, average received power, received timing / average delay, and spatial Rx parameter, where the spatial Rx parameter refers to a spatial (reception) channel characteristic parameter such as an angle of arrival.

[0132] A terminal may be configured by a list of up to M TCI-State settings in the higher layer parameter PDSCH-Config to decode a PDSCH with a detected PDCCH with DCI intended for the terminal and a given serving cell, where M depends on the UE capability.

[0133] Each TCI-State includes parameters for setting up a quasi co-location relationship between one or two DL reference signals and the DM-RS ports of the PDSCH.

[0134] Quasi co-location relationship is established by higher layer parameters qcl-Type1 for the first DL RS and qcl-Type2 (if configured) for the second DL RS. For two DL RSs, the QCL types are not the same, regardless of whether the references are the same DL RS or different DL RSs.

[0135] The quasi co-location type corresponding to each DL RS is given by the higher layer parameter qcl-Type in QCL-Info and can take one of the following values:

[0136] - "QCL-TypeA":{Doppler shift,Doppler spread,average delay,delay spread}

[0137] - "QCL-TypeB":{Doppler shift,Doppler spread}

[0138] - "QCL-TypeC":{Doppler shift, average delay}

[0139] - "QCL-TypeD":{Spatial Rx parameter}

[0140] For example, when a target antenna port is a specific NZP CSI-RS, the NZP CSI-RS antenna port may be instructed / configured to be QCLed with a specific TRS in terms of QCL-Type A and with a specific SSB in terms of QCL-Type D. A terminal receiving such instruction / configuration can receive the NZP CSI-RS using Doppler and delay values ​​measured in the QCL-TypeA TRS and apply the reception beam used for QCL-TypeD SSB reception to the NZP CSI-RS reception.

[0141] The UE can receive an activation command via MAC CE signaling that is used to map up to eight TCI states to codepoints in the DCI field "Transmission Configuration Indication".

[0142] Multi-TRP related operations

[0143] The Coordinated Multi Point (CoMP) technique is a method in which multiple base stations exchange (e.g., using the X2 interface) or utilize channel information (e.g., RI / CQI / PMI / LI (layer indicator)) fed back from terminals to transmit coordinated to terminals, effectively controlling interference. Depending on the method used, CoMP can be classified into joint transmission (JT), coordinated scheduling (CS), coordinated beamforming (CB), dynamic point selection (DPS), dynamic point blocking (DPB), etc.

[0144] The M-TRP transmission method, in which M TRPs transmit data to one terminal, can be broadly divided into i) eMBB M-TRP transmission, which is a method for increasing the transmission rate, and ii) URLLC M-TRP transmission, which is a method for increasing the reception success rate and reducing latency.

[0145] In addition, in terms of DCI transmission, the M-TRP transmission method can be divided into i) M-DCI (multiple DCI) based M-TRP transmission in which each TRP transmits different DCI, and ii) S-DCI (single DCI) based M-TRP transmission in which one TRP transmits DCI. For example, in the case of S-DCI based M-TRP transmission, all scheduling information for data transmitted by the M TRP needs to be transmitted to the terminal in one DCI, and it may be used in an ideal backhaul (ideal BH) environment in which dynamic coordination between both TRPs is possible.

[0146] The UE can recognize PUSCH (or PUCCH) scheduled by DCI received in different control resource sets (CORESETs) (or CORESETs belonging to different CORESET groups) as PUSCH (or PUCCH) transmitted in different TRPs or as PDSCH (or PDCCH) in different TRPs. In addition, the method for UL transmission (e.g., PUSCH / PUCCH) transmitted in different TRPs described later can be equally applied to UL transmission (e.g., PUSCH / PUCCH) transmitted in different panels belonging to the same TRP.

[0147] Hereinafter, the CORESET group identifier (group ID) described / mentioned in this disclosure may mean an index / identification information (e.g., ID) for distinguishing a CORESET for each TRP / panel. And, a CORESET group may be a group / union of CORESETs distinguished by an index / identification information (e.g., ID) for distinguishing a CORESET for each TRP / panel / the CORESET group ID. As an example, the CORESET group ID may be specific index information defined in a CORSET configuration. In this case, a CORESET group may be set / indicated / defined by an index defined in a CORESET configuration for each CORESET. And / or, the CORESET group ID may mean an index / identification information / indicator for distinguishing / identifying between CORESETs set / associated with each TRP / panel. Hereinafter, the CORESET group ID described / mentioned in the present disclosure may be expressed as a specific index / specific identification information / specific indicator for distinguishing / identifying between CORESETs set / associated with each TRP / panel. The CORESET group ID, i.e., a specific index / specific identification information / specific indicator for distinguishing / identifying between CORESETs set / associated with each TRP / panel, may be set / instructed to the terminal by higher layer signaling (e.g., RRC signaling) / Layer 2 signaling (L2 signaling, e.g., MAC-CE) / Layer 1 signaling (L1 signaling, e.g., DCI). As an example, it may be set / instructed to perform PDCCH detection for each TRP / panel (i.e., for each TRP / panel belonging to the same CORESET group) in the CORESET group unit.And / or, uplink control information (e.g., CSI, HARQ-A / N (ACK / NACK), SR (scheduling request)) and / or uplink physical channel resources (e.g., PUCCH / PRACH / SRS resources) may be configured / instructed to be managed / controlled separately for each TRP / panel (i.e., for each TRP / panel belonging to the same CORESET group) on a per-CORESET group basis. And / or, HARQ A / N (process / retransmission) for PDSCH / PUSCH, etc. scheduled for each TRP / panel (i.e., for each TRP / panel belonging to the same CORESET group) may be managed.

[0148] For example, a ControlResourceSet information element (IE), which is an upper layer parameter, is used to configure a time / frequency control resource set (CORESET). For example, the control resource set (CORESET) may be related to detection and reception of downlink control information. The ControlResourceSet IE may include a CORESET related ID (e.g., controlResourceSetID), a CORESET pool index (e.g., CORESETPoolIndex) for the CORESET, a time / frequency resource configuration of the CORESET, TCI information related to the CORESET, etc. As an example, a CORESET pool index (e.g., CORESETPoolIndex) may be set to 0 or 1. In the above description, the CORESET group may correspond to the CORESET pool, and the CORESET group ID may correspond to the CORESET pool index (e.g., CORESETPoolIndex).

[0149] A method for improving reliability in multi-TRP will be described below.

[0150] The following two methods can be considered as transmission and reception methods for improving reliability using transmission with multiple TRPs.

[0151] FIG. 7 illustrates a multiple TRP transmission method in a wireless communication system to which the present disclosure can be applied.

[0152] Referring to FIG. 7(a), a case is shown in which layer groups transmitting the same codeword (CW) / transport block (TB) correspond to different TRPs. In this case, a layer group can mean a predetermined layer set consisting of one or more layers. In this case, the amount of transmission resources increases due to the large number of layers, which has the advantage that robust channel coding with a low code rate can be used for the TB, and since the channels are different from the multiple TRPs, the reliability of the received signal can be improved based on diversity gain.

[0153] Referring to FIG. 7(b), an example is shown in which different CWs are transmitted in layer groups corresponding to different TRPs. In this case, it can be assumed that the TBs corresponding to CW #1 and CW #2 in the figure are the same. That is, CW #1 and CW #2 mean that the same TB is converted into different CWs by channel coding or the like according to different TRPs. Therefore, it can be considered as an example of repeated transmission of the same TB. FIG. 7(b) may have a disadvantage that the code rate corresponding to the TB is higher than that of FIG. 7(a). However, it has an advantage that the code rate can be adjusted by instructing different RV (redundancy version) values ​​for encoded bits generated from the same TB according to the channel environment, or the modulation order of each CW can be adjusted.

[0154] According to the schemes illustrated in Figures 7(a) and 7(b), the same TB is repeatedly transmitted in different layer groups, and each layer group is transmitted by a different TRP / panel, thereby increasing the probability of data reception by the terminal. This is called an SDM (Spatial Division Multiplexing)-based M-TRP URLLC transmission scheme. Layers belonging to different layer groups are transmitted by DMRS ports belonging to different DMRS CDM groups.

[0155] In addition, although the above-mentioned contents related to multiple TRPs have been described based on a spatial division multiplexing (SDM) scheme using different layers, this may of course be extended and applied to a frequency division multiplexing (FDM) scheme based on different frequency domain resources (e.g., RB / PRB (set), etc.) and / or a time division multiplexing (TDM) scheme based on different time domain resources (e.g., slots, symbols, sub-symbols, etc.).

[0156] A multi-TRP scheduled by at least one DCI may be performed as follows:

[0157] i) Scheme 1 (SDM): n (n is a natural number) TCI states in a single slot with overlapped time and frequency resource allocation

[0158] - Method 1a: Each transmission occasion is a layer or a set of layers of the same TB, and each layer or layer set is associated with one TCI and one set of DMRS ports. A single codeword with one redundancy version (RV) is used for all layers or layer sets. From the UE perspective, different coded bits are mapped to different layers or layer sets according to a specific mapping rule.

[0159] - Method 1b: Each transmission occasion is a layer or a set of layers of the same TB, and each layer or layer set is associated with one TCI and one set of DMRS ports. A single codeword with one RV is used for each spatial layer or layer set. The RV corresponding to each spatial layer or layer set may be the same or different.

[0160] - Approach 1c: Each transmission opportunity is one layer of the same TB with one DMRS port associated with multiple TCI state indices, or one layer of the same TB with multiple DMRS ports associated with multiple TCI indices one by one.

[0161] In approaches 1a and 1c above, the same MCS is applied to all layers or layer sets.

[0162] ii) Scheme 2 (FDM): n (n is a natural number) TCI states in a single slot with non-overlapping frequency resource allocations. Each non-overlapping frequency resource allocation is associated with one TCI state. The same single / multiple DMRS ports are associated with all non-overlapping frequency resource allocations.

[0163] - Method 2a: A single codeword with one RV is used across the entire resource allocation. From the UE perspective, a common RB mapping (codeword to layer mapping) is applied across all resource allocations.

[0164] - Scheme 2b: A single codeword with one RV is used for each non-overlapping frequency resource allocation. The RVs corresponding to each non-overlapping frequency resource allocation may be the same or different.

[0165] In scheme 2a, the same MCS is applied to all non-overlapping frequency resource allocations.

[0166] iii) Scheme 3 (TDM): n (n is a natural number) TCI states in a single slot with non-overlapping time resource allocation. Each transmission opportunity in a TB has one TCI and one RV with mini-slot time granularity. All transmission opportunities in a slot use a common MCS with the same single or multiple DMRS ports. The RV / TCI states may be the same or different in a transmission opportunity.

[0167] iv) Scheme 4 (TDM): n (n is a natural number) TCI states in K (n<=K, K is a natural number) distinct slots. Each transmit opportunity in TB has one TCI and one RV. All transmit opportunities across K slots use a common MCS with the same single or multiple DMRS ports. The RV / TCI states may be the same or different in the transmit opportunities.

[0168] Hereinafter, in this disclosure, DL MTRP-URLLC means that the M-TRP transmits the same data (e.g., transport block (TB)) / DCI using different layer / time / frequency resources. For example, TRP 1 transmits the same data / DCI using resource 1, and TRP 2 transmits the same data / DCI using resource 2. A UE configured with the DL MTRP-URLLC transmission method receives the same data / DCI using different layer / time / frequency resources. Here, the UE may be instructed by the base station which QCL RS / type (i.e., DL TCI state) to use in the layer / time / frequency resource that receives the same data / DCI. For example, when the same data / DCI is received in resource 1 and resource 2, the DL TCI state to be used in resource 1 and the DL TCI state to be used in resource 2 are instructed. Since the UE receives the same data / DCI in resource 1 and resource 2, high reliability can be achieved. Such a DL MTRP URLLC may be applied to the PDSCH / PDCCH.

[0169] Conversely, UL MTRP-URLLC means that M-TRP receives the same data / UCI from a certain UE using different layer / time / frequency resources. For example, TRP 1 receives the same data / UCI from the UE using resource 1, and TRP 2 receives the same data / UCI from the UE using resource 2, and then shares the received data / UCI through a connected backhaul link between the TRPs. A UE configured with the UL MTRP-URLLC transmission method transmits the same data / UCI using different layer / time / frequency resources. Here, the UE is instructed by the base station which Tx beam and which Tx power (i.e., UL TCI state) should be used in the layer / time / frequency resource that transmits the same data / UCI. For example, when the same data / UCI is transmitted in resource 1 and resource 2, the UL TCI state to be used in resource 1 and the UL TCI state to be used in resource 2 are instructed. Such UL MTRP URLLC may be applied to PUSCH / PUCCH.

[0170] In the method proposed in this document, the use ( / mapping) of a specific TCI state (or TCI) when receiving data / DCI / UCI for a certain frequency / time / space resource can mean, in DL, estimating a channel from a DMRS using a QCL type and QCL RS indicated by the TCI state in the frequency / time / space resource, and receiving / demodulating data / DCI in the estimated channel, and in UL, transmitting / modulating a DMRS and data / UCI using a Tx beam and / or Tx power indicated by the TCI state in the frequency / time / space resource.

[0171] The UL TCI state includes the Tx beam and / or Tx power information of the UE, and instead of the TCI state, spatial relation info, etc. may be set to the UE by other parameters. The UL TCI state may be directly indicated in the UL grant DCI, or may mean the spatial relation info of the SRS resource indicated in the SRS resource indicator (SRI) field of the UL grant DCI. Or, it may mean the open loop (OL) Tx power control parameters (j: index for open loop parameters Po and alpha (up to 32 parameter value sets per cell), q_d: index of DL RS for path loss (PL) measurement (up to 3 measurements per cell), l: closed loop power control process index (up to 2 processes per cell)) linked to the value indicated in the SRI field of the UL grant DCI.

[0172] On the other hand, MTRP-eMBB means that the M-TRP transmits different data using different layers / times / frequencies, and it is assumed that a UE configured with the MTRP-eMBB transmission method is instructed of various TCI states by DCI, and the data received using the QCL RS for each TCI state is different data from each other.

[0173] In addition, the UE can know whether it is MTRP URLLC transmission / reception or MTRP eMBB transmission / reception by separately distinguishing between the RNTI for MTRP-URLLC and the RNTI for MTRP-eMBB. That is, if the CRC of DCI is masked using the RNTI for URLLC, it is recognized as URLLC transmission, and if the CRC of DCI is masked using the RNTI for eMBB, it is recognized as eMBB transmission. Alternatively, the base station may configure the UE for MTRP URLLC transmission / reception or MTRP eMBB transmission / reception by other new signaling.

[0174] For convenience of explanation, the present disclosure applies the proposed method assuming cooperative transmission / reception between two TRPs, but the method can be extended to a multi-TRP environment of three or more, and can also be extended to a multi-panel environment. Different TRPs may be recognized as different TCI (Transmission Configuration Indication) states by the UE. That is, when the UE receives / transmits data / DCI / UCI using TCI state 1, it means that the UE receives / transmits data / DCI / UCI from / to TRP 1.

[0175] The proposals of the present disclosure may be utilized in situations where MTRPs transmit PDCCHs cooperatively (repeatedly or separately transmit the same PDCCH), and some of the proposals may also be utilized in situations where MTRPs transmit PDSCHs cooperatively or receive PUSCHs / PUCCHs cooperatively.

[0176] In addition, in the following disclosure, the meaning of multiple base stations (i.e., MTRPs) repeatedly transmitting the same PDCCH may mean transmitting the same DCI using multiple PDCCH candidates, and is the same as the meaning of multiple base stations repeatedly transmitting the same DCI. The same DCI may mean two DCIs having the same DCI format / size / payload. Or, even if the payloads of two DCIs are different, they may be called the same DCI if the scheduling results are the same. For example, the slot / symbol position of data and the slot / symbol position of acknowledgement (ACK) / non-acknowledgement (NACK) are relatively determined based on the reception time of the DCI according to the time domain resource allocation (TDRA) field of the DCI. Here, if the DCI received at time n and the DCI received at time n+1 inform the UE of the same scheduling result, the TDRA fields of both DCIs will be different, and as a result, the DCI payloads will have to be different. The number of repetitions R may be directly instructed by the base station to the UE or may be mutually agreed upon. Alternatively, even if the payloads of two DCIs are different and the scheduling results are not the same, if the scheduling result of one DCI is a subset of the scheduling result of another DCI, they can be said to be the same DCI. For example, when the same data is TDM-transmitted N times, DCI 1 received before the first data indicates data repetition N times, and DCI 2 received after the first data and before the second data indicates data repetition N-1 times. The scheduling data of DCI 2 is a subset of the scheduling data of DCI 1, and both DCIs are scheduled for the same data, so in this case, they can also be said to be the same DCI.

[0177] In addition, in the following disclosure, when multiple base stations (i.e., MTRPs) transmit the same PDCCH in a divided manner, it means that one DCI is transmitted by one PDCCH candidate, and some resources in which the PDCCH candidate is defined are transmitted by TRP 1, and the remaining resources are transmitted by TRP 2. For example, when TRP 1 and TRP 2 transmit PDCCH candidates corresponding to aggregation level m1+m2 in a divided manner, the PDCCH candidates are divided into PDCCH candidate 1 corresponding to aggregation level m1 and PDCCH candidate 2 corresponding to aggregation level m2, and TRP 1 transmits PDCCH candidate 1 and TRP 2 transmits PDCCH candidate 2 in different time / frequency resources. After receiving PDCCH candidate 1 and PDCCH candidate 2, the UE generates PDCCH candidates corresponding to aggregation level m1+m2 and attempts DCI decoding.

[0178] When the same DCI is divided into multiple PDCCH candidates and transmitted, there are two possible implementation methods.

[0179] First, the DCI payload (control information bits + CRC) may be encoded by one channel encoder (e.g., a polar encoder), and the two TRPs may transmit the resulting coded bits separately. In this case, the coded bits transmitted by each TRP may encode the entire DCI payload or only a portion of the DCI payload. Second, the DCI payload (control information bits + CRC) may be divided into two (DCI 1 and DCI 2), each of which may be encoded by a channel encoder (e.g., a polar encoder). Then, the two TRPs may transmit the coded bits corresponding to DCI 1 and the coded bits corresponding to DCI 2, respectively.

[0180] In summary, multiple base stations (ie, MTRPs) may transmit the same PDCCH separately / repeatedly for multiple monitoring occasions (MOs) as follows.

[0181] i) It may mean repeatedly transmitting coded DCI bits obtained by encoding the entire DCI content of the PDCCH in each MO for each base station (i.e., STRP); or

[0182] ii) It may mean dividing the coded DCI bits obtained by encoding the entire DCI content of the PDCCH into a plurality of parts and transmitting different parts to each base station (i.e., STRP) in each MO; or

[0183] iii) This may mean dividing the DCI content of the corresponding PDCCH into multiple parts, separately encoding different parts for each base station (i.e., STRP), and transmitting them in each MO.

[0184] That is, regardless of whether the PDCCH is repeatedly transmitted or divided, it may be understood that the PDCCH is transmitted multiple times at multiple transmission times (TOs: transmission opportunities). Here, TO refers to a specific time / frequency resource unit in which the PDCCH is transmitted. For example, if the PDCCH is transmitted multiple times in slots 1, 2, 3, and 4 (in a specific resource block (RB)), TO may refer to each slot, if the PDCCH is transmitted multiple times in RB sets 1, 2, 3, and 4 (in a specific slot), TO may refer to each RB set, or if the PDCCH is transmitted multiple times at different times and frequencies, TO may refer to each time / frequency resource. In addition, the TCI state used for DMRS channel estimation may be set differently for each TO, and TOs set to different TCI states may be assumed to be transmitted by different TRPs / panels. The fact that multiple base stations repeatedly transmit or divide the PDCCH means that the PDCCH is transmitted in multiple TOs, and the union of the TCI states set in the TOs is composed of two or more TCI states. For example, when the PDCCH is transmitted in TOs 1, 2, 3, and 4, TCI states 1, 2, 3, and 4 may be set in TOs 1, 2, 3, and 4, respectively, which means that TRP i transmits the PDCCH in TO i in a coordinated manner.

[0185] For multiple TOs instructed to the UE to repeatedly or separately transmit PDCCH / PDSCH / PUSCH / PUCCH, each TO is UL transmitted to a specific TRP or DL ​​received from a specific TRP. Here, a UL TO transmitted to TRP 1 (or a TO of TRP 1) refers to a TO using the first value of two spatial relations, two UL TCIs, two UL power control parameters, and / or two path loss reference signals (PLRSs) instructed to the UE, and a UL TO transmitted to TRP 2 (or a TO of TRP 2) refers to a TO using the second value of two spatial relations, two UL TCIs, two UL power control parameters, and / or two PLRSs instructed to the UE. Similarly, during DL transmission, a DL TO sent by TRP 1 (or a TO of TRP 1) means a TO using the first value of two DL TCI states (e.g., when two TCI states are set in CORESET) instructed to the UE, and a DL TO sent by TRP 2 (or a TO of TRP 2) means a TO using the second value of two DL TCI states (e.g., when two TCI states are set in CORESET) instructed to the UE.

[0186] The proposal of the present disclosure can be expanded and applied to various channels such as PUSCH / PUCCH / PDSCH / PDCCH.

[0187] The proposal of the present disclosure can be extended to both cases where the channel is repeatedly transmitted on different time / frequency / spatial resources and where it is separately transmitted.

[0188] Data transmission and HARQ (Hybrid Automatic Repeat and reQuest)-ACK (Acknowledgement) process

[0189] FIG. 8 illustrates a HARQ-ACK process for downlink data in a wireless communication system to which the present disclosure can be applied.

[0190] Referring to Figure 8, the terminal can detect the PDCCH in slot #n. Here, the PDCCH includes downlink scheduling information (e.g., DCI format 1_0, 1_1), and the PDCCH indicates DL assignment-to-PDSCH offset (K0) and PDSCH-HARQ-ACK reporting offset (K1). For example, the DCI formats 1_0, 1_1 may include the following information:

[0191] - Frequency domain resource assignment: Indicates the RB resources (e.g., one or more (non-)contiguous RBs) assigned to the PDSCH.

[0192] - Time domain resource assignment: K0, indicates the starting position (e.g., OFDM symbol index) and length (e.g., number of OFDM symbols) of the PDSCH in a slot

[0193] - PDSCH HARQ feedback timing indicator (PDSCH-to-HARQ_feedback timing indicator): indicates K1

[0194] - HARQ process number (4 bits): indicates the HARQ process ID (Identity) for data (e.g., PDSCH, TB).

[0195] - PUCCH resource indicator (PRI): indicates a PUCCH resource to be used for UCI transmission among multiple PUCCH resources in a PUCCH resource set.

[0196] Thereafter, the terminal may receive the PDSCH at slot #(n+K0) according to the scheduling information of slot #n, and then transmit the UCI via the PUCCH at slot #(n+K1). Here, the UCI includes a HARQ-ACK response to the PDSCH. If the PDSCH is configured to transmit up to one TB, the HARQ-ACK response may be configured with 1 bit. If the PDSCH is configured to transmit up to two TBs, the HARQ-ACK response may be configured with 2 bits if spatial bundling is not configured, and may be configured with 1 bit if spatial bundling is configured. If the HARQ-ACK transmission time for multiple PDSCHs is specified as slot #(n+K1), the UCI transmitted at slot #(n+K1) includes a HARQ-ACK response for multiple PDSCHs.

[0197] Multimedia Broadcast / Multicast Service (MBMS)

[0198] 3GPP MBMS is divided into i) single frequency network (SFN) scheme where multiple base station cells synchronize to transmit the same data via PMCH (physical multicast channel) and ii) single cell point to multipoint (SC-PTM) scheme where broadcasting is performed within the cell coverage via PDCCH / PDSCH channels. The SFN scheme is used to provide broadcasting services to a wide area (e.g. MBMS area) using resources allocated statically in advance, while the SC-PTM scheme is mainly used to provide broadcasting services only within the cell coverage using dynamic resources.

[0199] The SC-PTM provides a single cell multicast control channel (SC-MCCH) which is one logical channel, and a single cell multicast traffic channel (SC-MTCH) which is one or more logical channels. These logical channels are mapped to a downlink shared channel (DL-SCH) which is a transport channel, and a physical channel (PDSCH). The PDSCH which transmits the SC-MCCH or SC-MTCH data is scheduled via a PDCCH indicated by a group-RNTI (G-RNTI). At this time, a temporary multicast group ID (TMGI) corresponding to a service identity (ID) may be one-to-one mapped to a specific G-RNTI value. Therefore, when a base station provides multiple services, multiple G-RNTI values ​​may be assigned for SC-PTM transmission. One or multiple terminals may perform PDCCH monitoring using a specific G-RNTI for receiving a specific service. Here, a DRX on-duration period dedicated to the SC-PTM can be set for a specific service / specific G-RNTI. In this case, these terminals wake up only during a specific on-duration period and perform PDCCH monitoring for the G-RNTI.

[0200] MBS (multicast broadcast service) related channels / signal transmission and reception methods

[0201] - PUCCH: Physical Uplink Control channel

[0202] - PUSCH: Physical Uplink Shared Channel

[0203] - MCCH: Multicast Control Channel

[0204] - MTCH: Multicast Traffic Channel

[0205] - RRM: Radio resource management

[0206] - RLM: Radio link monitoring

[0207] - SCS: Sub-carrier spacing

[0208] - RLM: Radio link monitoring

[0209] - DCI: Downlink Control Information

[0210] - CAP: Channel Access Procedure

[0211] - Ucell: Unlicensed cell

[0212] - PCell: Primary Cell

[0213] - PSCell: Primary SCG Cell

[0214] - TBS: Transport Block Size

[0215] - TDRA: Time Domain Resource Allocation

[0216] -SLIV: Starting and Length Indicator Value (an indication value for the starting symbol index and number of symbols in a slot of a PDSCH and / or PUSCH. It may be set as a component of an entry constituting a TDRA field in a PDCCH that schedules the PDSCH and / or PUSCH.)

[0217] - BWP: Bandwidth Part (may be composed of consecutive resource blocks (RB) on the frequency axis. It may correspond to one numerology (e.g., SCS, CP length, slot / mini-slot duration, etc.). In addition, multiple BWPs may be configured on one carrier (the number of BWPs per carrier may also be limited), but the number of activated BWPs may be limited to a portion (e.g., 1) per carrier.)

[0218] -CORESET: Control resource set (COntrol REsourse SET) (meaning a time-frequency resource region in which PDCCH can be transmitted, the number of CORESETs per BWP may be limited.)

[0219] - REG: Resource element group

[0220] - SFI: Slot Format Indicator (an indicator indicating the symbol level DL / UL direction in a specific slot, transmitted on a group common PDCCH)

[0221] - COT: Channel occupancy time

[0222] - SPS: Semi-persistent scheduling

[0223] - QCL: Quasi-Co-Location (QCL relationship between two reference signals (RSs)) means that QCL parameters such as Doppler shift, Doppler spread, average delay, delay spread, and spatial Rx parameters obtained from one RS can be applied to the other RS ​​(or antenna port of the RS). In the NR system, four QCL types are defined as follows: "typeA": {Doppler shift, Doppler spread, average delay, delay spread}, "typeB": {Doppler shift, Doppler spread}, "typeC": {Doppler shift, average delay}, and "typeD": {Spatial Rx parameter}. For a DL RS antenna port, the first DL RS is set as a reference for QCL type X (X=A, B, C, or D), and the second DL RS is set as a reference for QCL type X (X=A, B, C, or D). RS may be set as a reference to QCL type Y (Y=A, B, C, or D, where X≠Y).

[0224] -TCI: Transmission Configuration Indication (One TCI state includes a QCL relationship between one or more DL RSs, such as a DM-RS port of a PDSCH, a DM-RS port of a PDCCH, or a CSI-RS port of a CSI-RS resource. For the "Transmission Configuration Indication" field in the DCI that schedules the PDSCH, the TCI state index corresponding to each code point constituting the field is activated by a MAC control element (CE), and the TCI state setting for each TCI state index is set by RRC signaling. In the Rel-16 NR system, the TCI state is set between DL RSs, but in future releases, the setting between DL RSs and UL RSs or between UL RSs and UL RSs may be allowed. Examples of UL RSs include SRS, PUSCH DM-RS, and PUCCH DM-RS.)

[0225] - SRI: SRS resource indicator (Indicates one of the SRS resource index values ​​set in the 'SRS resource indicator' field in the DCI that schedules the PUSCH. When transmitting the PUSCH, the UE may transmit the PUSCH using the same spatial domain transmission filter used for transmitting and receiving a reference signal associated with the SRS resource. Here, the reference RS is set by RRC signaling according to the SRS spatial relationship information (SRS-SpatialRelationInfo) parameter for each SRS resource, and the SS / PBCH block, CSI-RS, or SRS may be set as the reference RS.)

[0226] - TRP: Transmission and Reception Point

[0227] - PLMN ID: Public Land Mobile Network identifier

[0228] - RACH: Random Access Channel

[0229] - RAR: Random Access Response

[0230] - Msg3: C-RNTI MAC CE or CCCH (common control channel) service data unit (SDU) is transmitted via an uplink shared channel (UL-SCH) and is provided by higher layers. It is a message associated with the UE Contention Resolution Identity as part of the random access procedure.

[0231] Special Cell: In dual connectivity operation, the term special cell refers to a PCell of a master cell group (MCG) or a PSCell of a secondary cell group (SCG) depending on whether the MAC entity is associated with the MCG or the SCG, respectively. Alternatively, the term special cell refers to a PCell. A special cell supports PUCCH transmission and contention-based random access and is always activated.

[0232] - Serving Cell: Includes PCell, PSCell, and SCell (secondary cell).

[0233] - CG: Configured Grant

[0234] - Type 1 CG or Type 2 CG: Type 1 configured grant or Type 2 configured grant

[0235] - Fall-back DCI: Indicates a DCI format available for fall-back operation, for example, DCI format 0_0, 1_0.

[0236] - Non-fallback DCI: This refers to a DCI format other than the fallback DCI, for example DCI format 0_1 ​​and 1_1.

[0237] - SS: Search space

[0238] - FDRA: Frequency domain resource allocation

[0239] - TDRA: Time domain resource allocation

[0240] - LP, HP: Low(er) priority, High(er) priority

[0241] A / N for cell A: A / N (acknowledgement / negative acknowledgement) information for data (e.g., PDSCH) received in cell A

[0242] - UL CI: Uplink cancelation indication

[0243] - CFR: Common frequency resource for MBS (multicast and broadcast service). One DL CFR provides group common PDCCH and group common PDSCH transmission resources for MBS transmission and reception. One UL CFR provides HARQ-ACK PUCCH resources for group common PDSCH reception. One CFR is one MBS specific BWP or one UE specific BWP. Alternatively, one or more CFRs may be configured within one UE specific BWP. One CFR is connected to one UE specific BWP.

[0244] - TMGI: Temporary Mobile Group Identity. An MBS service identifier that indicates a specific service.

[0245] - G-RNTI: Group Radio Network Temporary Identifier, which indicates the identifier of a group of terminals receiving the MBS.

[0246] The above-mentioned contents (such as 3GPP system, frame structure, NR system, etc.) may be applied in combination with the method proposed in the present disclosure described below, or may help clarify the technical features of the method proposed in the present disclosure. In this disclosure, " / " means "and", "or", or "and / or" depending on the context.

[0247] In the prior art, a base station can configure a terminal-dedicated SPS configuration for a specific terminal and allocate downlink SPS transmission resources that are repeated at a set period. Here, a DCI of a terminal-dedicated PDCCH can indicate SPS activation of a specific SPS configuration index, so that the terminal can repeatedly receive the SPS transmission resources at a set period. Such SPS transmission resources are used for initial HARQ (hybrid automatic repeat request) transmission, and a base station can allocate retransmission resources for a specific SPS configuration index using a DCI of a terminal-dedicated PDCCH. For example, if a terminal reports a HARQ NACK for an SPS transmission resource, the base station can allocate retransmission resources by a DCI so that the terminal can receive downlink retransmission. In addition, a DCI of a terminal-dedicated PDCCH can indicate deactivation (SPS release or SPS deactivation) of a specific SPS configuration index, and a terminal that receives this does not receive the indicated SPS transmission resource. Here, a cyclic redundancy check (CRC) of the DCI for activation / retransmission / deactivation of the SPS is scrambled with a Configured Scheduling-RNTI (CS-RNTI).

[0248] An improved wireless communication system (e.g., Rel-17 NR system) is intended to introduce a DL broadcast or DL ​​multicast transmission method to support a Multicast Broadcast Service (MBMS) service similar to the existing MBMS (e.g., LTE MBMS). A base station provides a point-to-multipoint (PTM) transmission method and / or a point-to-point (PTP) transmission method for transmitting DL broadcast or DL ​​multicast.

[0249] In the PTM transmission method for MBS, a base station transmits a group common PDCCH and a group common PDSCH to multiple terminals, and the multiple terminals simultaneously receive the same group common PDCCH and group common PDSCH transmissions and decode the same MBS data.

[0250] Meanwhile, in the PTP transmission method for MBS, a base station transmits a terminal-dedicated PDCCH and a terminal-dedicated PDSCH to a specific terminal, and only the terminal receives the terminal-dedicated PDCCH and the terminal-dedicated PDSCH. Here, when there are multiple terminals receiving the same MBS service, the base station transmits the same MBS data to each terminal individually through different terminal-dedicated PDCCHs and terminal-dedicated PDSCHs. That is, the same MBS data is provided to multiple terminals, but different channels (i.e., PDCCHs and PDCCHs) are used for each terminal.

[0251] As described above, in the PTM transmission scheme, a base station transmits multiple group-common PDSCHs to multiple terminals, where the base station can receive HARQ-ACKs from multiple terminals for the group-common PDSCHs using PUCCH resources dedicated to the terminals.

[0252] Here, when a TB (Transport Block) for a multicast PDSCH (or a group common PDSCH) is successfully decoded, the terminal transmits ACK as the HARQ-ACK information. On the other hand, when a TB (Transport Block) cannot be successfully decoded, the terminal transmits NACK as the HARQ-ACK information. Such a HARQ-ACK transmission method is called an ACK / NACK based HARQ-ACK method (mode). In general, a terminal can transmit an ACK / NACK based HARQ-ACK using a terminal dedicated PUCCH resource.

[0253] On the other hand, when a NACK only based HARQ-ACK method (mode) is configured for a multicast PDSCH (or a group-common PDSCH), the terminal does not transmit a PUCCH when there is an ACK, and transmits a PUCCH only when there is a NACK. Here, the PUCCH may transmit only a NACK as HARQ-ACK information in a group-common PUCCH resource.

[0254] Hereinafter, in the present disclosure, a DCI format (or PDCCH) that schedules PDSCH reception carrying an MBS service (i.e., MBS TB) may be referred to as an MBS DCI format (or PDCCH) or a multicast DCI format (or PDCCH). For example, a DCI format (or PDCCH) that includes a CRC scrambled by a G-RNTI (group-RNTI) or G-CS-RNTI (group-configured scheduling-RNTI) that schedules PDSCH reception may be referred to as an MBS DCI format (or PDCCH) or a multicast DCI format (or PDCCH). Herein, unless otherwise specified in the present disclosure, the MBS DCI format (or PDCCH) or the multicast DCI format (or PDCCH) may include both a group common DCI format (or PDCCH) according to the PTM scheme for MBS and a UE specific DCI format (or PDCCH) according to the PTP scheme for MBS.

[0255] Furthermore, unless otherwise specified in this disclosure (e.g., the distinction between PDSCH by dynamic scheduling and PDSCH by SPS), PDSCH scheduled by MBS DCI format (or PDCCH) or multicast DCI format (or PDCCH) (also, PDSCH scheduled by UE-specific DCI format (or PDCCH) in the PTP scheme) and group-common SPS PDSCH can be collectively referred to as MBS PDSCH or multicast PDSCH. In other words, unless otherwise specified in this disclosure, MBS PDSCH or multicast PDSCH may include both group-common PDSCH in the PTM scheme for MBS and UE-specific PDSCH in the PTP scheme for MBS.

[0256] In addition, HARQ-ACK information associated with a multicast (or MBS) DCI format (or PDCCH) or a multicast PDSCH may be referred to as MBS HARQ-ACK information or multicast HARQ-ACK information. Unless otherwise specified in the present disclosure, such MBS HARQ-ACK information or multicast HARQ-ACK information may be transmitted via a UE-specific PUCCH / PUSCH according to the PTP / PTM scheme, or may be transmitted via a group-common PUCCH / PUSCH according to the PTM scheme.

[0257] Furthermore, unless otherwise specified in this disclosure (eg, the distinction between PDSCH by dynamic scheduling and PDSCH by SPS), the PDSCH scheduled by the unicast DCI format (or PDCCH) and the UE-specific SPS PDSCH may be collectively referred to as a unicast / UE-specific PDSCH.

[0258] In addition, in the present disclosure, when a TB (Transport Block) for an MBS PDSCH or a multicast PDSCH is successfully decoded, the terminal can transmit an ACK as HARQ-ACK information. On the other hand, when a TB for an MBS PDSCH or a multicast PDSCH cannot be successfully decoded, the terminal can transmit a NACK as HARQ-ACK information. Such a HARQ-ACK transmission method is called an ACK / NACK based HARQ-ACK method (mode).

[0259] On the other hand, if the TB for the MBS PDSCH or the multicast PDSCH is successfully decoded, the terminal does not need to transmit HARQ-ACK information (i.e., ACK) via PUCCH (or PUSCH). On the other hand, if the TB for the MBS PDSCH or the multicast PDSCH cannot be successfully decoded, the terminal can transmit NACK as HARQ-ACK information. Such a HARQ-ACK transmission method is called a NACK-based HARQ-ACK method (mode). In other words, when a NACK only based HARQ-ACK method (mode) is configured, the terminal does not transmit PUCCH (or PUSCH) if it is ACK, and can transmit PUCCH (or PUSCH) only if it is NACK.

[0260] In addition, in this disclosure, a sub-slot, a mini-slot, and a symbol slot all refer to a time unit smaller than one slot, and unless otherwise clearly described in this disclosure, all may be interpreted as having the same meaning. Furthermore, all of these terms may be considered / interpreted as one or more symbols in a slot.

[0261] FIG. 9 illustrates a HARQ-ACK transmission and reception procedure for a multicast PDSCH according to one embodiment of the present disclosure.

[0262] FIG. 9(a) illustrates a signaling procedure between UE1 and a base station (gNB) (beam / TRP 1), and FIG. 9(b) illustrates a signaling procedure between UE2 and a base station (gNB) (beam / TRP 2). FIG. 9(a) illustrates a case where there is no retransmission of PDSCH, and FIG. 9(b) illustrates a case where there is retransmission of PDSCH. FIG. 9 illustrates two procedures together for convenience of explanation, but is not limited thereto. That is, UE1 and UE2 are not limited to be connected to the same base station (through different beams / TRPs), and the two procedures are not limited to be performed together. In other words, FIG. 9(a) and FIG. 9(b) are separate procedures, but are illustrated together for convenience of explanation, and a common description is given for common steps.

[0263] 1. Although not shown in FIG. 9, (before the procedure of FIG. 9) the UE may enter RRC_CONNECTED mode and send a message / information to the base station indicating one or more interested MBS services.

[0264] A. The message / information may be conveyed by any one of uplink control information (UCI), a MAC control element (CE), and an RRC message.

[0265] B. The MBS service of interest in the message / information may refer to one of the TMGI or G-RNTI included in the DL message received from the base station.

[0266] For example, the DL message may be a service availability message including TMGI#1, TMGI#3, TMGI#5 and TMGI#10. If the UE is interested in TMGI#5, the UE can indicate the order of TMGI#5 in the message / information, i.e., the UE can report "3" to the base station.

[0267] As another example, the DL message may be a service availability message including G-RNTI#1, G-RNTI#3, G-RNTI#5, and G-RNTI#10. If the UE is interested in G-RNTI#10, the UE may indicate the order of G-RNTI#10 in the message / information. That is, the UE may report "4" to the base station.

[0268] 2. Upon receiving the message / information, the base station can transmit at least one of the following to the UE via an RRC message (S901a, S901b): i) a common frequency resource (CFR) configuration; ii) one or more group common PDSCH configurations including a TCI state for one or more G-RNTI values; and iii) a search space (SS) configuration including a TCI state for one or more G-RNTI values.

[0269] FIG. 9 illustrates an example of one RRC message, but is not limited to this, and the configurations i) to iii) may be provided to the UE in different (or partially identical) RRC messages.

[0270] A UE that has received an RRC message from a base station can configure one or more group-common PDSCH (eg, group-common SPS PDSCH) settings through the RRC message.

[0271] The A. RRC message may be a group common message transmitted on a PTM MCCH (Multicast Control Channel) or a UE dedicated message transmitted on a UE specific DCCH (Dedicated Control Channel).

[0272] B. The UE may be configured with at least a G-RNTI value for each MBS CFR or each serving cell, or in addition, may be configured with a group common-configured scheduling-RNTI (GC-CS-RNTI) to be used for activation, retransmission, or deactivation of one or more group common SPS configurations.

[0273] - If the UE does not configure a GC-CS-RNTI for a CFR or serving cell, and a CS-RNTI is configured for the CFR or serving cell, the UE may use the CS-RNTI to activate, retransmit, or deactivate one or more group-common SPS configurations.

[0274] - The base station may associate a list of TMGIs or a list of G-RNTIs with one GC-CS-RNTI. In this case, the base station may provide the terminal with a list of TMGIs or a list of G-RNTIs associated with the GC-CS-RNTI value.

[0275] C. Each PDSCH configuration (eg, RRC parameter PDSCH-config) may include at least information elements (IEs) for multicast and / or broadcast, as shown in Table 6 below.

[0276] Table 6 illustrates the PDSCH-Config IE used to configure the PDSCH parameters.

[0277] [Table 6]

[0278] Table 7 illustrates the description of the fields of PDSCH-config in Table 6 above.

[0279] [Table 7-1] [Table 7-2]

[0280] 3. Once a search space (SS) for the configured CFR is configured, the UE monitors the PDCCH on the configured SS within the configured CFR to receive DCI whose CRC is scrambled with the G-RNTI or G-CS-RNTI (S902a, S902b).

[0281] 4. If the data unit is available on the Multicast Traffic Channel (MTCH) of the MBS radio bearer (MRB) for the MBS service, the base station constructs and transmits a transport block (TB) including a data unit for an SPS PDSCH occasion that is associated with i) the MTCH of the MRB for the MBS service, ii) the TMGI of the MBS service, iii) the short ID of the MBS service, or iv) the G-RNTI mapped to the MBS service through service-to-resource mapping.

[0282] In the group common dynamic scheduling of TB, the base station transmits DCI on the PDCCH to the UE (S903a, S903b).

[0283] Here, the CRC of the DCI may be scrambled by a G-RNTI, a G-CS-RNTI, or a CS-RNTI, and the PDCCH may be a group-common PDCCH or a UE-specific PDCCH.

[0284] FIG. 9 illustrates a case where a group common DCI with a scrambled CRC attached (included) in G-RNTI#1 is transmitted and repetition=3.

[0285] The DCI may include the following information (fields):

[0286] - Identifier for DCI formats: This field can indicate an MBS specific DCI format or one of the existing DCI formats for the MBS.

[0287] - Carrier indicator: This information (field) indicates the (serving or MBS specific) cell of the CFR in which the group common PDCCH / PDSCH is transmitted or the serving cell of the active BWP of the UE associated with the CFR.

[0288] - Bandwidth part indicator: This field indicates the BWP ID assigned to the CFR on which the group common PDCCH / PDSCH is transmitted or the BWP ID of the active BWP of the UE associated with the CFR.

[0289] In addition, the DCI may include a frequency domain resource assignment, a time domain resource assignment, a VRB-to-PRB mapping, a PRB bundling size indicator, a rate matching indicator, a ZP CSI-RS trigger, a modulation and coding scheme, a new data indicator (NDI), a redundancy version, a HARQ process number, a downlink assignment index, a transmit power control (TPC) command for scheduled PUCCH, a PUCCH resource indicator (PRI), a HARQ feedback timing indicator for PDSCH (PDSCH-to-HARQ_feedback timing indicator), an antenna port, a PUCCH resource indicator (PRI), a PDSCH-to-HARQ_feedback timing indicator, an antenna port, an antenna number, an antenna assignment index, a PUCCH resource indicator (PRI), a PDSCH-to-HARQ_feedback timing indicator, an antenna number ... The information may include information regarding the following: a) the number of active ports, b) a transmission configuration indication (TCI), c) an SRS request, d) a DMRS sequence initialization, and d) a priority indicator.

[0290] In group-common dynamic scheduling, the base station may provide the UE with one or more of the following service-to-resource mappings for the MBS service identified by the TMGI or G-RNTI or GC-CS-RNTI by i) a group-common or UE-specific RRC message, or ii) a group-common or UE-specific MAC CE. Data of the MBS service may be carried over an MBS Radio Bearer (MRB) of an MTCH associated with the MBS service, which is a multicast traffic logical channel. The RRC message may be a group-common message transmitted over a PTM Multicast Control Channel (MCCH) or a UE-dedicated message transmitted over a UE-specific Dedicated Control Channel (DCCH). The DCI scheduling the PDSCH carrying the MBS service data may also indicate one or more of a short ID, an MTCH ID, an MRB ID, a G-RNTI value, and a TMGI value for the MBS service.

[0291] 5. When the UE receives a DCI whose CRC is scrambled by the G-RNTI that the UE is interested in receiving, based on i) the mapping between the MBS service and the HARQ process number (HPN) indicated in the DCI, and / or ii) (if available) the mapping between the MBS service and the short ID indicated in the DCI, the UE can determine the MBS service associated with one or more of the short ID, MTCH ID, MRB ID, G-RNTI value, and TMGI value for each PDSCH occasion.

[0292] The base station transmits a PDSCH carrying the MBS service data to the UE (S904a, S904b) (FIG. 9 illustrates the case where MBS service data mapped to G-RNTI#1 is transmitted), and if the UE is interested in the determined MBS service, it can receive a PDSCH transmission scheduled by the DCI (S905a, S905b).

[0293] On the other hand, unlike the example of FIG. 9, if the UE is not interested in the determined MBS service, the UE does not need to receive the PDSCH transmission scheduled by the DCI.

[0294] Then, depending on the decoding status of the PDSCH transmission, the UE sends HARQ feedback to the base station.

[0295] 6. A UE that has received a group-common DCI indicating PUCCH resources for an MBS HARQ-ACK may transmit an HARQ-ACK to the base station via a PUCCH after receiving a PDSCH scheduled by the DCI (S906a) as follows:

[0296] In A.PTM method 1, the group-common DCI can indicate at least a single PUCCH resource indicator (PRI) and a single PDSCH-to-HARQ_feedback timing indicator (K1) for ACK / NACK-based HARQ-ACK.

[0297] B. In UE-specific PUCCH resource allocation for ACK / NACK based HARQ-ACK for group-common DCI, different UEs in a group may be configured with at least PUCCH resources and other values ​​of candidate DL data-UL ACK (e.g., dl-DataToUL-ACK) in the UE-dedicated PUCCH configuration (e.g., PUCCH-config) for multicast or for unicast (if PUCCH-config for multicast is not configured).

[0298] Different PUCCH resources may be assigned to different UEs according to the same PUCCH resource indicator (PRI) and the same PDSCH-to-HARQ_feedback timing indicator (K1) of the group-common DCI.

[0299] C. In PTP retransmission, the PUCCH resource indicator (PRI) and PDSCH-to-HARQ_feedback timing indicator (K1) in the UE-specific DCI may be analyzed based on the PUCCH configuration for unicast (e.g., PUCCH-config), regardless of whether the PUCCH configuration for multicast (e.g., PUCCH-config) is configured or not.

[0300] D. PRI (PUCCH Resource Indicator) may be indicated by group common DCI as follows.

[0301] 1) Option 1A-1: A list of UE-specific PRIs may be included in the DCI.

[0302] - Each PRI in the list may point to an entry corresponding to a candidate PUCCH resource ID (e.g., pucch-ResourceId) value in a PUCCH configuration (e.g., PUCCH-config) for the same or different PUCCH resource allocation for other UEs in the group that have received the same DCI. Other PRIs in the DCI may point to other entries in the PUCCH configuration (e.g., PUCCH-config).

[0303] - The candidate PUCCH resource ID (e.g., pucch-ResourceId) value is configured by a higher layer (e.g., RRC), and other PUCCH resource ID (e.g., pucch-ResourceId) values ​​may be configured for other UEs of the same group at least in the multicast PUCCH configuration (e.g., PUCCH-config).

[0304] 2) Option 1A-2: A group common PRI may be included in the DCI.

[0305] - A single group common PRI may indicate a corresponding entry for a candidate PUCCH resource ID (e.g., pucch-ResourceId) value in a UE-specific PUCCH configuration (e.g., PUCCH-config) for the same or different PUCCH resource allocation for all UEs in the group.

[0306] - The candidate PUCCH resource ID (e.g., pucch-ResourceId) value is configured by a higher layer (e.g., RRC), and different PUCCH resource ID (e.g., pucch-ResourceId) values ​​may be configured for different UEs of the same group, at least in the PUCCH configuration (e.g., PUCCH-config) for multicast.

[0307] - If a PUCCH configuration for multicast (e.g., PUCCH-config) is configured for HARQ-ACK for a group-common PDSCH scheduled by a group-common DCI, the UE may assume that the PRI of the group-common DCI indicates a corresponding entry for a candidate PUCCH resource ID (pucch-ResourceId) value in the PUCCH configuration for multicast (e.g., PUCCH-config). That is, the PRI value of the group-common DCI may be parsed based on the PUCCH configuration for multicast (e.g., PUCCH-config).

[0308] - On the other hand, if a PUCCH configuration for multicast (e.g., PUCCH-config) is not configured for HARQ-ACK for a group-common PDSCH scheduled by a group-common DCI, the UE may assume that the PRI of the group-common DCI indicates a corresponding entry for a candidate PUCCH resource ID (pucch-ResourceId) value in the PUCCH configuration for unicast (e.g., PUCCH-config). That is, the PRI value of the group-common DCI may be analyzed based on the PUCCH configuration for unicast (e.g., PUCCH-config).

[0309] E.K1 (PDSCH-to-HARQ_feedback timing indicator) may be indicated by group common DCI as follows:

[0310] 1) Option 1B-1: A list of UE-specific K1 values ​​may be included in the DCI.

[0311] - Each K1 in the list can indicate the same UL slot or different UL (sub)slots for different UEs in the group.

[0312] As an example, different K1 values ​​may be assigned to different UEs, e.g., K1-UE1, K2-UE2, K3-UE3, ...

[0313] As another example, the K1 value may be shared among multiple UEs (eg, K1-UE1 / UE2, K2-UE3 / UE4).

[0314] As another example, one K1 value may be a reference and other K1 values ​​may be assigned based on the reference, e.g., a list of {K1_ref, K1_offset (offset from reference)} may be indicated in the DCI.

[0315] For example, UE1 may use K1_ref, UE2 may use K1_ref+K1_offest1, and UE3 may use K1_ref+K1_offest2.

[0316] 2) Option 1B-2: A group-common K1 value may be included in the DCI.

[0317] - A single K1 value may be the same for all UEs in a group receiving the DCI or may indicate a corresponding entry for a candidate DL Data-UL ACK value (e.g., dl-DataToUL-ACK) in a UE specific PUCCH configuration (e.g., PUCCH-config) for different PUCCH resource allocations. This may apply when the DCI format of the DCI is configured in the UE specific PUCCH configuration (e.g., PUCCH-config) for the K1 value.

[0318] - Candidate DL Data-UL ACK values ​​(eg, dl-DataToUL-ACK) are configured by higher layers (eg, RRC) and may be different for different UEs of the same group at least in the PUCCH configuration for multicast (eg, PUCCH-config).

[0319] - If a PUCCH configuration for multicast (e.g., PUCCH-config) is configured for HARQ-ACK for a group-common PDSCH scheduled by a group-common DCI, the UE may assume that the K1 value of the group-common DCI indicates a corresponding entry for a candidate DL data-UL ACK value (e.g., dl-DataToUL-ACK) in the PUCCH configuration for multicast (e.g., PUCCH-config). That is, the K1 value of the group-common DCI may be parsed based on the PUCCH configuration for multicast (e.g., PUCCH-config).

[0320] - On the other hand, if the PUCCH configuration for multicast (e.g., PUCCH-config) is not configured for HARQ-ACK for group-common PDSCH scheduled by group-common DCI, the UE may assume that the K1 value of the group-common DCI indicates a corresponding entry for a candidate DL data-UL ACK value (e.g., dl-DataToUL-ACK) in the PUCCH configuration for unicast (e.g., PUCCH-config). That is, the K1 value of the group-common DCI may be analyzed based on the PUCCH configuration for unicast (e.g., PUCCH-config).

[0321] In addition, when receiving a group common DCI whose CRC is scrambled by the G-RNTI and / or a UE-specific DCI whose CRC is scrambled by the C-RNTI, if a Type-1 HARQ-ACK codebook for the PUCCH-config for multicast and / or the PUCCH-config for unicast is configured, the UE can configure a Time Domain Resource Allocation (TDRA) and generate a Type-1 HARQ-ACK codebook for the HARQ-ACK for the group common PDSCH scheduled by the group common DCI and / or the UE-specific PDSCH scheduled by the UE-specific DCI.

[0322] 7. If decoding of the TB on the PDSCH transmission opportunity fails, the UE may transmit a HARQ NACK to the base station on a PUCCH resource within the configured UL CFR (S906b).

[0323] By using the PUCCH resources, the UE can also transmit HARQ-ACKs for other PDSCH transmissions, such as unicast SPS PDSCH, dynamic unicast PDSCH, PTP retransmissions, and / or dynamic group common PDSCH. In this case, the UE can construct a codebook based on one or more options in step 7 to multiplex the HARQ-ACK on the PUCCH with (sub)slots for SPS PDSCH for multicast, SPS PDSCH for unicast, dynamically scheduled multicast PDSCH, and / or dynamically scheduled unicast PDSCH.

[0324] If a reference signal received power (RSRP) threshold is set, the UE can use NACK only based HARQ-ACK based on the measured RSRP of the serving cell. For example, if the measured RSRP is higher than the threshold, the NACK only based HARQ-ACK may be transmitted on a group common PUCCH resource indicated by the PRI of the DCI. On the other hand, if the measured RSRP is lower than the threshold, the NACK only based HARQ-ACK may be changed to a HARQ-ACK based HARQ-ACK and transmitted on a UE specific PUCCH resource indicated by the PRI of the DCI.

[0325] On the other hand, if a PDSCH aggregation factor (pdsch-AggregationFactor) is set for the G-RNTI or the base station indicates a repetition number (repeat_number) in the DCI, the TB scheduled by the group-common DCI may be repeated for the Nth HARQ transmission of the TB in each symbol allocation in each of the PDSCH aggregation factor (pdsch-AggregationFactor) consecutive slots or in each of the repetition number (repeat_number) consecutive slots.

[0326] 8. The base station that receives the HARQ NACK in the TCI state can retransmit the PDCCH and PDSCH in the TCI state within the DL CFR configured for the retransmission of the TB. The UE can monitor the group-common and / or UE-specific PDCCH in the TCI state on the search space configured in the DL CFR to receive the retransmission of the TB (S907b).

[0327] The base station may retransmit the TB to only one of the UEs in the group via the UE-specific PDCCH, and the other UEs may not receive the retransmission of the TB (eg, because the other UEs have successfully received the TB).

[0328] 9. If the UE receives a PDCCH for retransmission of the TB (S908b), the UE can receive a PDSCH scheduled by the DCI of the PDCCH (S909b, S910b).

[0329] If the UE successfully decodes a TB on the PDSCH, the UE may assume that the decoded TB is associated with the MTCH, MRB, TMGI, G-RNTI and / or short ID of the MBS service based on the mapping between the MBS service indicated by the DCI and the HPN (HARQ process number) and / or the mapping between the MBS service indicated by the DCI and the short ID (if available).

[0330] 10. If TB decoding is successful on the PDSCH transmission opportunity, the UE may transmit a HARQ ACK to the base station on the PUCCH resource in the UL CFR set by step 7. On the other hand, if TB decoding on the PDSCH transmission opportunity fails, the UE may transmit a HARQ NACK to the base station on the PUCCH resource in the set UL CFR (S911b).

[0331] By using the PUCCH resources, the UE can also transmit HARQ-ACKs for other PDSCH transmissions, such as unicast SPS PDSCH, dynamic unicast PDSCH, PTP retransmissions, and / or dynamic group common PDSCH. In this case, the UE can construct a codebook based on one or more options in step 7 to multiplex the HARQ-ACK on the PUCCH with (sub)slots for SPS PDSCH for multicast, SPS PDSCH for unicast, dynamically scheduled multicast PDSCH, and / or dynamically scheduled unicast PDSCH.

[0332] Meanwhile, the example of FIG. 9 is for convenience of explanation and does not limit the scope of the present disclosure. Some steps illustrated in FIG. 9 may be omitted depending on the situation and / or setting. Also, the base station and the terminal in FIG. 9 are merely examples and may be embodied by the device illustrated in FIG. 12 below. For example, the processor (102 / 202) in FIG. 12 may control the transceiver 106 / 206 to transmit and receive channels / signals / data / information, etc., and may also control the memory (104 / 204) to store the transmitted or received channels / signals / data / information, etc.

[0333] A base station may collectively refer to an object that transmits and receives data to and from a terminal. For example, the base station may be a concept including one or more TPs (Transmission Points), one or more TRPs (Transmission and Reception Points), etc. Also, the TP and / or TRP may include a panel of a base station, a transmission and reception unit, etc. Also, the term "TRP" may be substituted with expressions such as a panel, an antenna array, a cell (e.g., a macro cell / small cell / pico cell, etc.), a TP (transmission point), a base station (gNB, etc.), etc. As described above, the TRP may be classified according to information (e.g., an index, an ID) related to a CORESET group (or a CORESET pool). As an example, when one terminal is configured to transmit and receive data to and from multiple TRPs (or cells), this may mean that multiple CORESET groups (or CORESET pools) are configured for one terminal. Such configuration of a CORESET group (or a CORESET pool) may be performed by higher layer signaling (eg, RRC signaling, etc.).

[0334] 9, for convenience of explanation, signaling between one base station and a terminal is considered, but the signaling method may be extended to signaling between multiple TRPs and multiple UEs. Alternatively, the base station may include multiple TRPs, or may be one cell including multiple TRPs.

[0335] FIG. 10 illustrates transmission and reception of a group common channel and a corresponding HARQ-ACK report in a wireless communication system to which the present disclosure can be applied.

[0336] Referring to Figure 10, G-RNTI DCI means DCI having a CRC scrambled by the G-RNTI, i.e., group common DCI, and can schedule a group common PDSCH. A terminal can receive group common PDCCH / PDSCH scheduled by different G-RNTIs based on a frequency division multiplexing (FDM) scheme and / or a time division multiplexing (TDM) scheme.

[0337] As shown in Fig. 10, in the existing MBS service, the group-common DCI can schedule the group-common PDSCH in the same cell. The terminal can perform HARQ-ACK reporting for the group-common PDSCH in the same cell.

[0338] The base station may configure / provide a PDSCH configuration for a common frequency resource (CFR) to the terminal separately from a PDSCH configuration (e.g., PDSCH Config) for the BWP. In this case, the CFR may be associated with an active BWP of the terminal, and some parameters may be commonly configured for the CFR and the BWP.

[0339] Therefore, the base station may not repeat (i.e., do not repeatedly set) some parameters in the PDSCH configuration for CFR and the PDSCH configuration for BWP, but may set / provide some parameters only in one PDSCH configuration. That is, when the setting value for parameter A is the same in the PDSCH configuration for CFR and the PDSCH configuration for BWP, the base station may include parameter A only in the PDSCH configuration for BWP.

[0340] In an existing wireless communication system, in association with carrier aggregation (CA), a base station can configure a serving cell as a scheduling cell or a scheduled cell. For example, DCI transmitted in a scheduling cell may be configured / defined to schedule a PDSCH transmission in a scheduled cell.

[0341] In this case, a UE-specific search space (USS) is set in the scheduling cell, and a USS is not set in the scheduled cell. In this case, there is a problem that it may be unclear whether the scheduled cell for unicast can perform scheduling for multicast (i.e., group common transmission).

[0342] In the following, this disclosure proposes a method for setting / performing cross-carrier scheduling and / or intra-carrier scheduling for PTM transmission and PTP retransmission when the above-mentioned CA and / or DC (dual connectivity) (based on multiple cell groups) is configured.

[0343] FIG. 11 is a diagram illustrating an operation of a terminal in relation to group common transmission and reception according to an embodiment of the present disclosure.

[0344] FIG. 11 illustrates an operation of a terminal based on a proposed method in the present disclosure (e.g., any one or a combination of the detailed embodiments thereof in the first to fifth embodiments). The illustration in FIG. 11 is for convenience of explanation and does not limit the scope of the present disclosure. Some steps illustrated in FIG. 11 may be omitted depending on the situation and / or setting. Also, the terminal in FIG. 11 is only an example and may be embodied by the device illustrated in FIG. 18. For example, the processor 102 / 202 in FIG. 18 may control the transceiver 106 / 206 to transmit / receive channels / signals / data / information (e.g., RRC signaling, MAC CE, DCI for UL / DL scheduling, SRS, PDCCH, PDSCH, PUSCH, PUCCH, etc.) and may control the transmitted or received channels / signals / data / information to be stored in the memory 104 / 204.

[0345] Referring to FIG. 11, a terminal may receive a first DCI indicating a new data indicator (NDI) value and a HARQ process number (HPN) value in a first cell (S1110).

[0346] For example, the first cell may correspond to a scheduled cell based on carrier aggregation (CA) or may correspond to a secondary cell (SCell) (eg, a scheduled SCell).

[0347] Additionally or alternatively, the first DCI may be received by PDCCH monitoring for a common search space configured for the first cell.

[0348] Additionally or alternatively, the first DCI may correspond to a DCI format that is cyclic redundancy check (CRC) scrambled by a group-radio network temporary identifier (G-RNTI).

[0349] The terminal may receive, in the first cell, a group-common PDSCH scheduled by the first DCI (S1120).

[0350] For example, the transmission of the group-common PDSCH may correspond to an initial transmission of the PDSCH based on the group-common DCI.

[0351] Additionally or alternatively, the group-common PDSCH may include a multicast PDSCH and / or a broadcast PDSCH associated with a multicast broadcast service (MBS).

[0352] The UE may receive a second DCI indicating the NDI value and the HPN value in the second cell (S1130). That is, the NDI value and the HPN value indicated by the second DCI are the same as the NDI value and the HPN value indicated by the first DCI.

[0353] For example, the second cell may correspond to a scheduling cell based on CA, and may correspond to either a primary cell (PCell) or a secondary cell (SCell) (eg, a scheduling PCell / scheduling SCell).

[0354] Additionally or alternatively, the second DCI may be received by PDCCH monitoring for a user equipment-specific search space configured in the second cell.

[0355] Additionally or alternatively, the second DCI may correspond to a DCI format that is CRC scrambled by a common-radio network temporary identifier (C-RNTI).

[0356] The terminal may receive a terminal-dedicated (i.e., terminal-specific) PDSCH scheduled (e.g., cross-carrier scheduled) by the second DCI in the first cell (S1140). At this time, the terminal-dedicated PDSCH may be determined and received as a retransmission of a transport block of the group common PDSCH based on a preset condition. That is, a transport block (TB) of the group common PDSCH may be retransmitted via the terminal-dedicated PDSCH. For example, a PTP PDSCH retransmission in the first cell for a PTM PDSCH transmission in the first cell may be (cross-carrier) scheduled by a DCI (e.g., terminal-dedicated DCI) in the second cell.

[0357] For example, the pre-set conditions may include a case where cross-carrier scheduling for retransmission of the TB is set.

[0358] Additionally or alternatively, the predefined condition may include a case where a common frequency resource (CFR) configuration is associated with an active bandwidth part (BWP) of the first cell. In this regard, the second DCI may further include a carrier indicator field (CIF) indicating the first cell.

[0359] FIG. 12 is a diagram illustrating the operation of a network device in relation to group common transmission and reception according to an embodiment of the present disclosure.

[0360] FIG. 12 illustrates an operation of a network device (e.g., a base station, a TRP, etc.) based on a proposed method (e.g., any one or a combination of the detailed embodiments thereof) in the present disclosure. The illustration in FIG. 12 is for convenience of explanation and does not limit the scope of the present disclosure. Some steps illustrated in FIG. 12 may be omitted depending on the situation and / or setting. Also, in FIG. 12, the base station is only an example and may be embodied by the device illustrated in FIG. 18. For example, the processor 102 / 202 in FIG. 18 can control the transceiver 106 / 206 to transmit / receive channels / signals / data / information, etc. (e.g., RRC signaling, MAC CE, DCI for UL / DL scheduling, SRS, PDCCH, PDSCH, PUSCH, PUCCH, etc.) and can control the transmitted or received channels / signals / data / information, etc. to be stored in the memory 104 / 204.

[0361] Referring to FIG. 12, the network device may transmit a first DCI indicating a new data indicator (NDI) value and a HARQ process number (HPN) value in a first cell (S1210).

[0362] For example, the first cell may correspond to a scheduled cell based on carrier aggregation (CA) or may correspond to a secondary cell (SCell) (eg, a scheduled SCell).

[0363] Additionally or alternatively, the first DCI may be received by the terminal's PDCCH monitoring for a common search space configured for the first cell.

[0364] Additionally or alternatively, the first DCI may correspond to a DCI format that is cyclic redundancy check (CRC) scrambled by a group-radio network temporary identifier (G-RNTI).

[0365] The network device may transmit a group-common PDSCH scheduled by the first DCI in the first cell (S1220).

[0366] For example, the transmission of the group-common PDSCH may correspond to an initial transmission of the PDSCH based on the group-common DCI.

[0367] Additionally or alternatively, the group-common PDSCH may include a multicast PDSCH and / or a broadcast PDSCH associated with a multicast broadcast service (MBS).

[0368] The network device may transmit a second DCI indicating the NDI value and the HPN value in the second cell (S1230), that is, the NDI value and the HPN value indicated by the second DCI are the same as the NDI value and the HPN value indicated by the first DCI.

[0369] For example, the second cell may correspond to a scheduling cell based on CA, and may correspond to either a primary cell (PCell) or a secondary cell (SCell) (eg, a scheduling PCell / scheduling SCell).

[0370] Additionally or alternatively, the second DCI may be received by the terminal's PDCCH monitoring for a user equipment-specific search space configured in the second cell.

[0371] Additionally or alternatively, the second DCI may correspond to a DCI format that is CRC scrambled by a common-radio network temporary identifier (C-RNTI).

[0372] The network device may transmit a terminal-dedicated (i.e., terminal-specific) PDSCH scheduled (e.g., cross-carrier scheduled) by the second DCI in the first cell (S1240). At this time, based on a preset condition, the terminal-dedicated PDSCH may be transmitted as a retransmission of a transport block of the group common PDSCH. That is, a transport block (TB) of the group common PDSCH may be retransmitted via the terminal-dedicated PDSCH. For example, a PTP PDSCH retransmission in the first cell for a PTM PDSCH transmission in the first cell may be (cross-carrier) scheduled by a DCI (e.g., terminal-dedicated DCI) in the second cell.

[0373] For example, the pre-set conditions may include a case where cross-carrier scheduling for retransmission of the TB is set.

[0374] Additionally or alternatively, the predefined condition may include a case where a common frequency resource (CFR) configuration is associated with an active bandwidth part (BWP) of the first cell. In this regard, the second DCI may further include a carrier indicator field (CIF) indicating the first cell.

[0375] Hereinafter, the present disclosure will describe specific examples related to the above-mentioned contents and procedures.

[0376] The embodiments of the present disclosure are distinguished only for the convenience of description, and part / all of the configuration of one embodiment may be applied in combination / combination with part / all of the configuration of another embodiment, or may be applied independently.

[0377] Example 1

[0378] This embodiment relates to a cross-carrier scheduling scheme related to PTP retransmission.

[0379] FIG. 13 illustrates an example of cross-carrier scheduling for PTP retransmission to which the embodiments of the present disclosure can be applied.

[0380] Referring to FIG. 13, PTM PDSCH transmission may be scheduled by G-RNTI DCI in a first cell (Cell1) (and / or a first BWP (BWP1)).

[0381] In this case, when the terminal transmits / reports NACK information for the PTM PDSCH to the base station as HARQ-ACK information, scheduling for PTP PDSCH retransmission (PTP ReTX PDSCH) in the first cell (Cell1) (and / or the first BWP (BWP1)) may be performed by the C-RNTI DCI in the second cell (Cell2) (and / or the second BWP (BWP2)).

[0382] That is, cross-carrier scheduling for PTP retransmission is supported, and the first cell (Cell1) (and / or the first BWP (BWP1)) may correspond to the scheduled cell, and the second cell (Cell2) (and / or the second BWP (BWP2)) may correspond to the scheduling cell.

[0383] In the following, in this embodiment, in relation to the above-mentioned cross-carrier scheduling, a proposed operation for a base station / terminal in a specific situation will be illustrated.

[0384] First, when UE specific DCI in a scheduling Scell ​​(Secondary cell) is configured to schedule a PDSCH on a scheduled PCell for unicast, the UE can perform PDCCH monitoring and / or PDSCH reception as follows.

[0385] For example, the UE may receive a group common DCI that schedules a PTM PDSCH transmission of a transport block (TB) on a scheduled PCell (PCell) that is scheduled in CFR based on a common search space (CSS) on the PCell. After the UE receives the group common DCI, the UE may receive a UE-specific DCI including a carrier indicator field (CIF), a new data indicator (NDI), and a HARQ process number (HPN) on a UE-specific search space (USS) of a scheduling SCell (SCell).

[0386] In this case, if the CIF indicates a PCell to which an active BWP of a UE is associated with a CFR (i.e., if a CFR is associated / configured to an active BWP of the PCell indicated by the CFI), and if the NDI and HPN values ​​in the UE-specific DCI are identical to the NDI and HPN values ​​in the group common DCI, the UE may determine / judge that the UE-specific DCI schedules a PTP PDSCH retransmission for the TB (i.e., the TB of a PTM PDSCH transmission). That is, the UE may receive the PDSCH scheduled by the UE-specific DCI as the PTP PDSCH retransmission. Otherwise (i.e., if there is no identity between the NDI and HPN values), the UE may determine / judge that the UE-specific DCI schedules a unicast transmission. That is, the UE may receive the PDSCH scheduled by the UE-specific DCI as a general unicast PDSCH transmission.

[0387] Alternatively, if the CIF indicates a PCell but the UE's active BWP of the PCell is not associated with a CFR, or if the CIF indicates an SCell, the UE may determine / judge that the UE-specific DCI schedules a unicast transmission. That is, the UE may receive a PDSCH scheduled by the UE-specific DCI as a unicast PDSCH transmission. The UE's determination / judgement may be made regardless of whether the NDI and HPN values ​​in the UE-specific DCI are the same as the NDI and HPN values ​​in the group-common DCI.

[0388] As another example, the UE may receive a group-common DCI that schedules a PTM PDSCH transmission of a transport block (TB) on a scheduled PCell (PCell) that is scheduled in CFR based on a common search space (CSS) on the PCell. After the UE receives the group-common DCI, the UE may receive a UE-specific DCI including a new data indicator (NDI) and a HARQ process number (HPN) on a UE-specific search space (USS) of a scheduling SCell (SCell).

[0389] In this case, when cross-carrier scheduling of PTP retransmission is configured without a CIF, if the NDI value and HPN value in the terminal-specific DCI are the same as the NDI value and HPN value in the group common DCI, the terminal can determine / judge that the terminal-specific DCI schedules a PTP PDSCH retransmission for the TB (i.e., the TB of PTM PDSCH transmission). That is, the terminal can receive the PDSCH scheduled by the terminal-specific DCI as the PTP PDSCH retransmission. The terminal's determination / judgement may be made regardless of the existence of a CIF in the terminal-specific DCI. Otherwise (i.e., if there is no identity between the NDI value and the HPN value), the terminal can determine / judge that the terminal-specific DCI schedules a unicast transmission. That is, the terminal can receive the PDSCH scheduled by the terminal-specific DCI as a general unicast PDSCH transmission.

[0390] Next, when UE specific DCI in a scheduling cell (e.g., a scheduling PCell / scheduling SCell) is configured to schedule a PDSCH in a scheduled SCell for unicast, the terminal can perform PDCCH monitoring and / or PDSCH reception as follows.

[0391] For example, if a UE is configured with CFR for a scheduled SCell and a specific CSS type (e.g., CSS Type 3 / Type-3 CSS) is not configured for the scheduled SCell, the UE can assume one or more of the following options (hereinafter, Option 1-1 to Option 1-4).

[0392] (Option 1-1) PTM PDSCH on a scheduled SCell is not scheduled by the scheduling SCell.

[0393] (Option 1-2) The PTM PDSCH on the scheduled SCell may be scheduled by the scheduling SCell based on the CSS configuration of the PCell.

[0394] (Options 1-3) If there is a CFR in the SCell to be scheduled, the terminal can invalidate it.

[0395] (Options 1-4) The PTM PDSCH on the scheduled SCell may be scheduled by the CSS on the scheduled SCell.

[0396] For example, the UE may receive a group-common DCI that schedules a PTM PDSCH transmission of a transport block (TB) in a scheduled PCell (SCell) scheduled in CFR. After the UE receives the group-common DCI, the UE may receive a UE-specific DCI including a carrier indicator field (CIF), a new data indicator (NDI), and a HARQ process number (HPN) in a UE-specific search space (USS) of a scheduling cell.

[0397] In this case, the case where cross-carrier scheduling of PTP retransmission in a scheduled SCell by a USS of a scheduling cell is configured is considered.

[0398] In this case, when the CIF indicates a scheduled SCell in which an active BWP of a terminal is associated with a CFR (i.e., when a CFR is associated / configured with an active BWP of the scheduled SCell indicated by the CFI), if the NDI and HPN values ​​in the terminal-specific DCI are identical to the NDI and HPN values ​​in the group common DCI, the terminal can determine / judge that the terminal-specific DCI schedules a PTP PDSCH retransmission for the TB (i.e., the TB of a PTM PDSCH transmission). That is, the terminal can receive the PDSCH scheduled by the terminal-specific DCI as the PTP PDSCH retransmission. Otherwise (i.e., there is no identity between the NDI and HPN values), the terminal can determine / judge that the terminal-specific DCI schedules a unicast transmission. That is, the terminal can receive the PDSCH scheduled by the terminal-specific DCI as a general unicast PDSCH transmission.

[0399] Alternatively, if the CIF indicates a scheduled SCell but the UE's active BWP of the scheduled SCell is not associated with a CFR, or if the CIF indicates a PCell or a scheduling SCell, the UE may determine / judge that the UE-specific DCI schedules a unicast transmission. That is, the UE may receive a PDSCH scheduled by the UE-specific DCI as a unicast PDSCH transmission. The UE's determination / judgement may be made regardless of whether the NDI and HPN values ​​in the UE-specific DCI are the same as the NDI and HPN values ​​in the group-common DCI.

[0400] Conversely, consider the case where cross-carrier scheduling of PTP retransmissions in a scheduled SCell is configured by the USS of a scheduling cell.

[0401] In this case, if the CIF indicates a scheduled SCell in which an active BWP of the UE is associated with a CFR (i.e., if a CFR is associated / configured with an active BWP of the scheduled SCell indicated by the CFI), if the NDI and HPN values ​​in the UE-specific DCI are identical to the NDI and HPN values ​​in the group common DCI, the UE may disable the UE-specific DCI. Otherwise (i.e., if there is no identity between the NDI and HPN values), the UE may determine / judge that the UE-specific DCI schedules a unicast transmission. That is, the UE may receive the PDSCH scheduled by the UE-specific DCI as a general unicast PDSCH transmission.

[0402] Alternatively, regardless of whether the NDI and HPN values ​​in the UE-specific DCI are the same as the NDI and HPN values ​​in the group-common DCI, the UE may determine / judge that the UE-specific DCI schedules a unicast transmission, i.e., the UE may receive the PDSCH scheduled by the UE-specific DCI as a unicast PDSCH transmission.

[0403] Additionally, in the case of carrier aggregation (CA) that considers cross-carrier scheduling for multicast reception, the terminal may be configured with cross-scheduling of PTM transmissions depending on the multicast DCI format.

[0404] For example, when DCI format 4_2 is configured, the terminal can perform cross-carrier scheduling or self-scheduling based on DCI format 4_2 (for example, self-scheduling in the present disclosure can mean that the scheduling grant (for example, DCI) and the scheduling assignment (for example, PDSCH scheduled by DCI) are transmitted and received in the same cell). In contrast, when DCI format 4_1 is configured, the terminal cannot perform cross-carrier scheduling, and instead, the terminal can only perform self-scheduling based on DCI format 4_1.

[0405] Additionally or alternatively, for the CA case, when cross-carrier scheduling or self-scheduling of PTM transmission is configured, the terminal may determine / judge cross-carrier scheduling or self-scheduling of TM transmission as follows: As an example, a terminal configured as a CSS for PTM transmission may monitor a group common PDCCH (GC-PDCCH) in a cell in which a CSS is configured for cross-carrier scheduling of PTM transmission. As another example, a terminal not configured as a CSS for PTM transmission may monitor a group common PDCCH (GC-PDCCH) in a cell in which a CSS is configured for self-scheduling of PTM transmission.

[0406] Additionally or alternatively, for the CA case, when cross-carrier scheduling or self-scheduling of PTM transmission is configured, the terminal may assume that cross-carrier scheduling or self-scheduling of PTP retransmission is also configured for PTP PDSCH in the same cell. Alternatively, the terminal may assume that cross-carrier scheduling or self-scheduling of PTP retransmission is configured separately.

[0407] In this regard, the terminal may determine cross-carrier scheduling or self-scheduling of PTP retransmission for the above-mentioned PTM transmission as in the following example. As an example, a terminal configured as a CSS for PTP retransmission may monitor a group common PDCCH (GC-PDCCH) in a cell in which a USS is configured for cross-carrier scheduling of PTP PDSCH retransmission in a cell in which a PTM transmission is received. As another example, a terminal configured as a CSS for PTP retransmission may monitor a group common PDCCH (GC-PDCCH) in a cell in which a USS is configured for self-scheduling of PTM PDSCH transmission in a cell in which a PTM transmission is received.

[0408] Example 2

[0409] This embodiment relates to a method for performing multicast reception in an SCell based on self-scheduling.

[0410] For example, assuming that the multicast DCI format does not include a CIF, a specific CSS type (e.g., CSS Type 3 / Type-3 CSS) needs to be configured in the SCell in order for the UE to monitor the multicast DCI format.

[0411] If a UE is configured with CFR in a scheduled SCell and the specific CSS type is not configured in the scheduled SCell, the UE can assume one or more of the following options (hereinafter, Option 2-1 to Option 2-4).

[0412] (Option 2-1) PTM in a scheduled SCell The PDSCH is not scheduled by the scheduled SCell.

[0413] In this regard, the PTM PDSCH in the scheduled SCell may be scheduled by the scheduling SCell. In the case of the CSS of the scheduling SCell, the multicast DCI format for scheduling the PTM PDSCH in the scheduled SCell may include a CIF. If the CIF is not included, the terminal may assume that the multicast DCI format in the scheduling cell schedules only the PTM PDSCH in the scheduled SCell.

[0414] (Option 2-2) PTM in a scheduled SCell. The PDSCH may be scheduled by the scheduled SCell based on the CSS configuration of the PCell.

[0415] In this regard, in the case of a CSS of a scheduled SCell, a multicast DCI format for scheduling a PTM PDSCH in the scheduled SCell may not include a CIF. The UE may assume that the multicast DCI format in the scheduled cell schedules only the PTM PDSCH in the scheduled SCell.

[0416] (Option 2-3) If there is a CFR in the SCell to be scheduled, the terminal can invalidate it.

[0417] (Option 2-4) A PTM PDSCH on a scheduled SCell may be scheduled by a CSS on a scheduling PCell or SCell, rather than being scheduled by the SCell (ie, cross-carrier scheduling).

[0418] In this regard, in the case of the CSS of the scheduling SCell, the multicast DCI format for scheduling the PTM PDSCH in the scheduled SCell may include a CIF. If the CIF is not included, the UE may assume that the multicast DCI format in the scheduling cell schedules only the PTM PDSCH in the scheduled SCell.

[0419] Example 3

[0420] This embodiment relates to a scheme for receiving multiple PDSCHs in multiple CFRs of multiple serving cells.

[0421] For example, depending on the UE capability, the UE can only receive on the SCell for multicast and not on the PCell at the same time.

[0422] For example, a case may be considered in which a terminal is interested in receiving multiple G-RNTIs on multiple serving cells (i.e., monitoring PDCCHs based on multiple G-RNTIs) but is unable to receive FDMed PDSCHs for the multiple G-RNTIs.

[0423] In relation to the above case, when multiple serving cells are configured for the same G-RNTI, the base station (e.g., gNB) may inform the terminal of information regarding which serving cell is used for PDSCH scheduling for the G-RNTI by certain signaling (e.g., RRC message / MAC-CE / DCI, etc.). The base station may also inform the terminal of information indicating that the serving cell has been changed to another serving cell for PDSCH scheduling for the G-RNTI.

[0424] Additionally or alternatively, in relation to the above case, if different search spaces for multicast are configured in one or more serving cells, or different search spaces for multicast in one or more serving cells overlap in the same slot, the base station / terminal can operate according to at least one of the following options (hereinafter, Option 3-1 to Option 3-4).

[0425] (Option 3-1) The terminal may prioritize PDCCH monitoring in a search space for multicast in a serving cell having the lowest serving cell index or the lowest CIF value. In relation to this, the terminal may drop PDCCH monitoring in a search space for multicast in other serving cells having a serving cell index higher than the lowest serving cell index or a CIF value higher than the lowest CIF value.

[0426] (Option 3-2) The UE may prioritize PDCCH monitoring in a search space for multicast on a PCell. In relation to this, the UE may drop PDCCH monitoring in a search space for multicast on a SCell.

[0427] (Option 3-3) The terminal may prioritize PDCCH monitoring in the search space for multicast in other serving cells to which other G-RNTIs with higher priority are mapped. In relation to this, the terminal may drop PDCCH monitoring in the search space for multicast in other serving cells to which G-RNTIs with lower priority are mapped.

[0428] Additionally or alternatively, when multiple serving cells are mapped to the same G-RNTI with high priority, the terminal may select a serving cell with the lowest serving cell index or the lowest CIF value from the multiple serving cells. In this case, the terminal may drop PDCCH monitoring in a search space for multicast in other serving cells mapped to the same G-RNTI. Alternatively, when multiple serving cells are mapped to G-RNTI with high priority, the terminal may select a PCell from the serving cell. In this case, the terminal may drop PDCCH monitoring in a search space for multicast in an SCell mapped to the same G-RNTI. Alternatively, when multiple serving cells are mapped to G-RNTI with high priority, the terminal may prioritize PDCCH monitoring in a search space for multicast with the lowest search space index in multiple serving cells mapped to the same G-RNTI. In this case, the terminal may drop PDCCH monitoring in other search spaces for multicast in multiple serving cells mapped to the same G-RNTI.

[0429] (Option 3-4) The terminal may prioritize PDCCH monitoring in a search space for multicast having the lowest search space index among multiple overlapping search spaces of one or more serving cells.

[0430] Additionally or alternatively, in relation to the above case, if PDSCHs in which multicast DCI overlaps in the same slot are scheduled in one or more serving cells and the scheduled PDSCHs transmit the same TB or different TBs for the same G-RNTI, the base station / terminal can operate according to at least one of the following options (hereinafter, Option 3-5 to Option 3-8).

[0431] (Option 3-5) The terminal can receive a PDSCH scheduled by a DCI indicating a high priority among the PDSCHs, while dropping reception of a PDSCH scheduled by a DCI indicating a low priority.

[0432] (Option 3-6) The terminal can receive the PDSCH on the PCell, but can drop the reception of the PDSCH on the SCell.

[0433] (Option 3-7) The terminal can receive the PDSCH in a cell having the lowest serving cell index or the lowest CIF value among the PDSCHs, while dropping the PDSCH reception in other cells.

[0434] (Option 3-8) The terminal receives a PDSCH scheduled by a DCI in a search space having the lowest search space index among the PDSCHs, while dropping reception of a PDSCH scheduled by a DCI in other search spaces.

[0435] Additionally or alternatively, in relation to the above case, if PDSCHs in which multicast DCI overlaps in the same slot are scheduled in one or more serving cells and the scheduled PDSCHs transmit TBs for different G-RNTIs, the base station / terminal can operate according to at least one of the following options (hereinafter, Option 3-9 to Option 3-12).

[0436] (Option 3-9) The terminal receives a PDSCH scheduled by a DCI for a G-RNTI having a high priority among the PDSCHs, while dropping PDSCH reception scheduled by a DCI for another G-RNTI having a low priority. In this regard, the base station can inform the terminal of information regarding the priority of each G-RNTI that the terminal intends to receive by certain signaling (e.g., RRC message / MAC-CE / DCI, etc.).

[0437] (Option 3-10) The terminal receives the PDSCH on the PCell, but can drop reception of the PDSCH on the SCell.

[0438] (Option 3-11) The terminal may receive the PDSCH in a cell having the lowest serving cell index or the lowest CIF value among the PDSCHs, while dropping the PDSCH reception in other cells.

[0439] (Option 3-12) The terminal can receive a PDSCH scheduled by a DCI in a search space having the lowest search space index among the PDSCHs, while dropping reception of a PDSCH scheduled by a DCI in other search spaces.

[0440] Additionally or alternatively, in relation to the above case, when PDSCHs in which multicast DCI overlaps in the same slot are scheduled in one or more serving cells and the terminal receives one of the PDSCHs, the terminal may include an ACK or NACK for the received PDSCH in the HARQ-ACK codebook according to a decoding result of the received PDSCH, whereas in this case, the terminal may include all NACKs for the other PDSCHs in the HARQ-ACK codebook.

[0441] In this regard, the terminal may transmit the HARQ-ACK codebook on a PUCCH and / or a PUSCH as in the following example. As an example, the terminal may always transmit the HARQ-ACK codebook on a PCell regardless of the cell in which the PDSCH is received. As another example, the terminal may transmit the HARQ-ACK codebook on a PUCCH-SCell if configured by the base station regardless of the cell in which the PDSCH is received. As yet another example, the terminal may transmit the HARQ-ACK codebook on a PUCCH-SCell or PCell of a PUCCH group to which the cell in which the PDSCH is received belongs.

[0442] Alternatively, if the terminal receives one of the PDSCHs and the scheduled PDSCHs transmit the same TB or different TBs for the same G-RNTI, the terminal may include all ACKs or all NACKs in the HARQ-ACK codebook for all scheduled PDSCHs according to the decoding result of the received PDSCHs. That is, the terminal may duplicate the decoding result of the received PDSCHs for all scheduled PDSCHs in the HARQ-ACK codebook.

[0443] Alternatively, if the terminal receives one of the PDSCHs and the scheduled PDSCH transmits the same TB or different TBs for the same G-RNTI, the terminal may include an ACK or NACK in the HARQ-ACK codebook for the received PDSCH according to the decoding result of the received PDSCH, whereas in this case, the terminal may not include HARQ feedback in the HARQ-ACK codebook for other PDSCHs.

[0444] Example 4

[0445] This embodiment relates to a scheme for transmitting and receiving a group-common PDCCH / PDSCH (e.g., a multicast PDCCH / PDSCH) when carrier aggregation (CA) (and / or dual connectivity (DC)) is configured for unicast.

[0446] Hereinafter, in this embodiment, a CA scheduled cell may refer to a cell that is scheduled by other cells in relation to CA, and a CA scheduling cell may refer to a cell that schedules other cells in relation to CA.

[0447] In relation to the transmission and reception of the above-mentioned group common PDCCH / PDSCH, at least one of the methods proposed in the present embodiment may be applied.

[0448] First, a method may be applied in which the CFR is not set in a CA scheduled cell, and the transmission of a group-common PDCCH / PDSCH (eg, a multicast PDCCH / PDSCH) is not supported.

[0449] In this case, the SS / CORESET for multicast is not configured in the scheduled cell. Additionally or alternatively, the UE may ignore the SS / CORESET for multicast in the scheduled cell, consider it an invalid setting, or determine that the SS / CORESET setting in the scheduled cell is not for multicast.

[0450] In this case, CFR may be configured only in a cell that performs CA scheduling, or transmission of a group-common PDCCH / PDSCH (eg, a multicast PDCCH / PDSCH) may be supported.

[0451] Next, a scheme may be applied in which a CFR is set in a CA scheduled cell to support group common transmission.

[0452] In relation to this, a PDCCH configuration (PDCCH-Config) and a PDSCH configuration (PDSCH-Config) used for multicast transmission may be configured / provided for the CFR of a scheduled cell. At this time, an SS / CORESET for multicast may be configured in the scheduled cell.

[0453] In this scheme, intra-carrier scheduling of unicast transmission may not be supported in a CA scheduled cell. However, when a PDCCH configuration (PDCCH-Config) and a PDSCH configuration (PDSCH-Config) for multicast are configured / provided in a scheduled cell, the UE is expected to be able to perform intra-carrier scheduling only for group common transmission as an exception.

[0454] Additionally or alternatively, a PDSCH configuration (PDSCH-Config) used for multicast transmission may be configured / provided for the CFR of a scheduled cell, but a PDCCH configuration (PDCCH-Config) used for multicast transmission may not be configured / provided.

[0455] In this case, as shown in the above-mentioned FIG. 13, the PDSCH of the CA scheduled cell may be scheduled using the DCI of the G-RNTI transmitted by the CA scheduling cell (i.e., cross-carrier scheduling). In this case, the DCI of the G-RNTI may include a cell index. The base station may set / provide the relevant information in an RRC message dedicated to an individual terminal so that the cell index of the group common DCI can be analyzed as the same cell by all terminals in the group.

[0456] If a CFR is configured in a CA scheduling cell, only cross-carrier scheduling may be possible if there is no PDSCH configuration for the CFR. In this regard, the terminal can only expect that the PDSCH of a CA scheduled cell is scheduled (i.e., cross-carrier scheduled) using the DCI of the G-RNTI transmitted in the CA scheduling cell. In this case, the group-common DCI of the G-RNTI does not need to include a cell index indicating the CA scheduled cell. In addition, the terminal can determine that the DCI of the G-RNTI transmitted in a specific CA scheduling cell cross-carrier schedules only the PDSCH of a specific CA scheduled cell according to the RRC message configuration of the base station.

[0457] Additionally or alternatively, when a CFR is configured in a CA scheduling cell, if there is a PDSCH configuration (PDSCH-Config) for the CFR, cross-carrier scheduling or intra-carrier scheduling may be indicated using a cell index of a group-common DCI. Thus, a terminal can receive a group-common PDSCH in a CA scheduled cell or a CA scheduling cell according to a cell index of a group-common DCI.

[0458] Next, even if there is a PDCCH configuration (PDCCH-Config) and a PDSCH configuration (PDSCH-Config) for group common (e.g., multicast) use for a CA scheduled cell, a scheme may be applied in which the terminal does not expect PTP retransmission from any cell from the base station. Alternatively, in this case, a scheme may be applied in which the terminal does not expect PTP retransmission only from a CA scheduled cell, but expects PTP retransmission only from a CA scheduling cell.

[0459] FIG. 14 illustrates an example of self-scheduling for PTP retransmission to which the embodiments of the present disclosure can be applied.

[0460] Referring to FIG. 14, a base station self-scheduling PTP retransmission for CA, DC and / or multiple BWP configurations is illustrated.

[0461] A PTM PDSCH transmission may be scheduled by the G-RNTI DCI in a first cell (e.g., Cell1) (and / or the first BWP (BWP1)). In this case, when the terminal transmits / reports NACK information for the PTM PDSCH to the base station as HARQ-ACK information, a C-RNTI DCI in a second cell (Cell2) (and / or the second BWP (BWP2)) may be scheduled for a PTP PDSCH retransmission (PTP ReTX PDSCH) in the second cell (Cell2) (and / or the second BWP (BWP2)).

[0462] In this regard, operation methods (hereinafter, methods 1 to 5) of a cell that schedules or is scheduled to perform group-common (eg, broadcast and / or multicast) transmission for an MBS may be as follows.

[0463] (Method 1) For example, when a base station receives a NACK (i.e., NACK information) from a specific terminal for a TB transmitted through a PTM PDSCH in a first cell (i.e., Cell1), the base station can schedule a PTP PDSCH retransmission in a second cell (i.e., Cell2) using DCI in the second cell. Here, the first cell may correspond to a CA scheduled cell, and the second cell may correspond to a CA scheduling cell. In this case, the base station may receive the NACK from the first cell by transmitting a UE-common PUCCH as shown in FIG. 14, or may receive the NACK from the second cell by transmitting a UE-specific PUCCH.

[0464] (Method 2) As another example, when a base station receives a NACK (i.e., NACK information) from a specific terminal for a TB transmitted via a PTM PDSCH in a first cell (i.e., Cell1), the base station can use a DCI in a second cell (i.e., Cell2) to instruct PTM transmission in the first cell and schedule PTP PDSCH retransmission in the second cell. Here, the first cell may correspond to a CA scheduled cell, and the second cell may correspond to a CA scheduling cell.

[0465] In this regard, the DCI of the second cell may include a cell index for the first cell and an indicator indicating / indicating that it is a PTP retransmission. Depending on the configuration of the base station, the terminal may soft combine the TB received via the PTM PDSCH of the first cell and the TB received via the PTP PDSCH retransmission of the second cell as a soft buffer of the same HARQ process according to the cell index for the first cell indicated by the DCI of the second cell. The base station may receive the NACK from the first cell as shown in FIG. 14 by UE-common PUCCH transmission, or may receive it from the second cell by UE-specific PUCCH transmission.

[0466] (Method 3) As yet another example, when a base station receives a NACK (i.e., NACK information) from a specific terminal for a TB transmitted by the base station through a PTM PDSCH in a first cell (i.e., Cell 1), the base station can schedule a PTP PDSCH retransmission in the first cell by using a DCI in a second cell (i.e., Cell 2). Here, the first cell may correspond to a CA scheduled cell, and the second cell may correspond to a CA scheduling cell.

[0467] In this regard, as shown in FIG 13, the DCI of the second cell may include a cell index for the first cell and an indicator indicating / indicating that it is a PTP retransmission. Depending on the base station configuration, the terminal may receive a PTP PDSCH retransmission in the first cell according to the cell index for the first cell indicated by the DCI of the second cell. The terminal may soft combine the TB received via the PTM PDSCH of the first cell and the TB received by the PTP PDSCH retransmission of the first cell as a soft buffer of the same HARQ process.

[0468] (Method 4) As yet another example, the base station can semi-statically match the PTM transmission of the first cell with the PTP retransmission of the second cell using certain signaling (e.g., RRC message / MAC-CE, etc.). In this case, the DCI for PTP retransmission does not need to indicate the cell for PTM transmission. The terminal can use certain signaling (e.g., RRC message / MAC-CE, etc.) to process the PTM transmission of the first cell and the PTP retransmission of the second cell as transmitting the same TB if the HARQ process number (HPN) of the DCI is the same, and soft combine them as soft buffers of the same HARQ process.

[0469] (Scheme 5) As yet another example, a CA scheduled cell can support both self-scheduling (i.e., self-carrier scheduling) and cross-carrier scheduling for PTP retransmission. That is, for PTP retransmission, the base station can transmit a PTP PDCCH in a CA scheduled cell or a CA scheduling cell, and transmit a PTP PDSCH in a CA scheduled cell. As an example, the base station can be configured to support any of the above-mentioned scheme 3 and scheme 1 or scheme 2. In this case, DCI for PTP retransmission may be transmitted on a PCell or SCell.

[0470] In the above-mentioned schemes (e.g., schemes 1 to 5), if the second cell is a CA scheduled cell, the DCI of the C-RNTI for scheduling the PTP retransmission may be transmitted in a common search space (CSS). Alternatively, if a UE-specific search space (USS) is configured for the second cell, the base station may schedule the PTP retransmission in the USS.

[0471] In the above-mentioned methods (for example, methods 1 to 5), when the second cell is a CA scheduling cell, the DCI of the C-RNTI that schedules the PTP retransmission can schedule the PTP retransmission in the CSS or USS.

[0472] Next, when there is a PDCCH configuration (PDCCH-Config) and a PDSCH configuration (PDSCH-Config) for group common (e.g., multicast) use for a CA scheduled cell, a scheme may be applied in which the terminal expects a PTP retransmission for a PTM initial transmission in the CA scheduled cell.

[0473] In this regard, operation schemes (hereinafter, schemes A to F) of a cell that schedules or is scheduled to perform group-common (eg, broadcast and / or multicast) transmission for an MBS may be as follows.

[0474] (Method A) For example, a case where PTP retransmission is self-scheduled (i.e., self-carrier scheduling) of a CA scheduled cell can be considered. In this case, when a base station receives a NACK (i.e., NACK information) from a specific terminal for a TB transmitted via a PTM PDSCH of a first cell, the base station can schedule a PTP PDSCH retransmission of the first cell using the DCI of the first cell. Here, the first cell may correspond to a CA scheduled cell.

[0475] For the first cell, which is a CA scheduled cell, the DCI of the C-RNTI for scheduling the PTP retransmission may be transmitted in the CSS. Alternatively, if the USS is configured for the first cell, the base station may schedule the PTP retransmission in the USS.

[0476] (Scheme B) As another example, the case where PTP retransmission is cross-carrier scheduling of CA scheduled cells can be considered.

[0477] FIG. 15 illustrates another example of cross-carrier scheduling for PTP retransmission to which the embodiments of the present disclosure can be applied.

[0478] Referring to FIG. 15, PTM PDSCH transmission may be scheduled by G-RNTI DCI in a first cell (Cell1) (and / or a first BWP (BWP1)).

[0479] In this case, when the terminal transmits / reports NACK information for the PTM PDSCH to the base station as HARQ-ACK information, scheduling for PTP PDSCH retransmission (PTP ReTX PDSCH) in the second cell (Cell2) (and / or the second BWP (BWP2)) may be performed by the C-RNTI DCI in the first cell (Cell1) (and / or the first BWP (BWP1)). That is, cross-carrier scheduling for PTP retransmission may be supported.

[0480] In this regard, when the base station receives a NACK from a specific terminal for a TB transmitted via the PTM PDSCH of the first cell as shown in Fig. 15, the base station may schedule a PTP PDSCH retransmission of the second cell using the DCI of the first cell. Here, the first cell may correspond to a CA scheduled cell, and the second cell may correspond to a CA scheduled cell or a CA scheduling cell.

[0481] That is, in the case of PTP retransmission, the PDCCH may be transmitted in a CA scheduled cell, and the PDSCH may be transmitted in another serving cell. In this case, for the first cell, which is a CA scheduled cell, the DCI of the C-RNTI for scheduling the PTP retransmission may be transmitted in the CSS. Alternatively, if the USS is configured in the first cell, the base station may schedule the PTP retransmission in the USS.

[0482] The terminal can soft-combine the TB received via the PTM PDSCH of the first cell and the TB received by retransmission of the PTP PDSCH of the second cell into a soft buffer of the same HARQ process.

[0483] (Scheme C) As yet another example, when a base station receives a NACK (i.e., NACK information) from a specific terminal for a TB transmitted via a PTM PDSCH in a first cell (i.e., Cell 1), the base station can schedule a PTP PDSCH retransmission in a second cell (i.e., Cell 2) using a DCI in the second cell. Here, both the first cell and the second cell may correspond to CA scheduled cells.

[0484] At this time, the base station may receive the NACK from the first cell by UE-common PUCCH transmission as shown in FIG. 14, or may receive the NACK from the second cell by UE-specific PUCCH transmission.

[0485] (Scheme D) As yet another example, when a base station receives a NACK (i.e., NACK information) from a specific terminal for a TB transmitted via a PTM PDSCH in a first cell (i.e., Cell1), the base station can use a DCI in a second cell (i.e., Cell2) to instruct the PTM transmission of the first cell and schedule a PTP PDSCH retransmission in the second cell. Here, both the first cell and the second cell may correspond to CA scheduled cells.

[0486] In this regard, the DCI of the second cell may include a cell index for the first cell and an indicator indicating / indicating that it is a PTP retransmission. Depending on the base station configuration, the terminal may soft-combine the TB received via the PTM PDSCH of the first cell and the TB received via the PTP PDSCH retransmission of the second cell as a soft buffer of the same HARQ process according to the cell index for the first cell indicated by the DCI of the second cell. The base station may receive the NACK from the first cell as shown in FIG. 14 by UE-common PUCCH transmission, or may receive it from the second cell by UE-specific PUCCH transmission.

[0487] (Method E) As yet another example, the base station can semi-statically match the PTM transmission of the first cell and the PTP retransmission of the second cell by certain signaling (e.g., RRC message / MAC-CE, etc.). In this case, the DCI for PTP retransmission does not need to indicate the cell for PTM transmission. The terminal can process the PTM transmission of the first cell and the PTP retransmission of the second cell as transmitting the same TB when the HARQ process number (HPN) of the DCI is the same by certain signaling (e.g., RRC message / MAC-CE, etc.), and soft combine them as soft buffers of the same HARQ process.

[0488] (Scheme F) As yet another example, a CA scheduled cell can support both self-scheduling (i.e., self-carrier scheduling) and cross-carrier scheduling for PTP retransmission. That is, for PTP retransmission, the base station can transmit a PTP PDCCH in a CA scheduled cell or a CA scheduling cell, and transmit a PTP PDSCH in a CA scheduled cell. As an example, the base station can be configured to support all of the above-mentioned schemes B and A, C, or D. In this case, DCI for PTP retransmission may be transmitted on a PCell or SCell.

[0489] In this embodiment, in relation to the above-mentioned scheme, the first cell may be replaced by a first BWP (i.e., BWP1), and the second cell may be replaced by a second BWP (i.e., BWP2). Here, the first BWP and the second BWP may be configured to belong to the same cell, or may be configured to belong to different cells.

[0490] Example 5

[0491] This embodiment relates to a scheme for overriding multicast SPS transmission with PTP retransmission or unicast transmission for the same or different services.

[0492] In the existing wireless communication system, the activation / deactivation of the multicast SPS is instructed / executed based on the DCI. However, the broadcast SPS may be activated using an RRC message instead of the DCI-based activation. In this case, since multiple terminals activate / deactivate the same broadcast SPS transmission, there is a problem that it is not clear when the activation / deactivation should be performed from the terminal's perspective.

[0493] Additionally, in connection with multicast SPS transmissions for the same or different services, when a terminal receives a PTP retransmission or a unicast transmission in the same slot, there is a problem that it is not clear which transmission the terminal should receive preferentially.

[0494] In order to solve the above problems, this embodiment proposes a scheme and related method for overriding multicast SPS transmission with PTP retransmission or unicast transmission for the same or different services.

[0495] FIG. 16 illustrates transmission and reception of unicast and multicast channels and a corresponding HARQ-ACK report in a wireless communication system to which the present disclosure can be applied.

[0496] Referring to Figure 16, G-RNTI DCI means DCI having CRC scrambled using G-RNTI, i.e., group common DCI, and can schedule multicast PDSCH. C-RNTI DCI means DCI having CRC scrambled using C-RNTI, and can schedule unicast PDSCH. Each DCI can indicate high priority or low priority.

[0497] The terminal can receive both unicast PDSCH and multicast PDSCH transmitted by FDM and / or TDM. For example, a unicast PDSCH opportunity may be transmitted by TDM with respect to a multicast PDSCH opportunity for G-RNTI#1, and a multicast PDSCH opportunity for G-RNTI#2 may be transmitted by FDM.

[0498] The base station may configure / provide a PDSCH configuration for a common frequency resource (CFR) to the terminal separately from a PDSCH configuration (e.g., PDSCH Config) for the BWP. In this case, the CFR may be associated with an active BWP of the terminal, and some parameters may be commonly configured for the CFR and the BWP.

[0499] Therefore, the base station may not repeat (i.e., do not repeatedly set) some parameters in the PDSCH configuration for CFR and the PDSCH configuration for BWP, but may set / provide some parameters only in one PDSCH configuration. That is, when the setting value for parameter A is the same in the PDSCH configuration for CFR and the PDSCH configuration for BWP, the base station may include parameter A only in the PDSCH configuration for BWP.

[0500] Additionally or alternatively, apart from the SPS configuration for unicast use, the CFR configuration may include a group-common SPS configuration, where the group-common SPS may mean an SPS for multicast use for connected terminals or an SPS for broadcast use for idle / inactive / connected terminals.

[0501] When multiple group common SPS configurations are configured / provided, or when both group common SPS configurations and terminal dedicated SPS configurations are configured / provided, a terminal receiving a CS-RNTI-based DCI for PTP retransmission for SPS can distinguish between different SPS configurations using the HARQ process ID included in the DCI.

[0502] For example, when a terminal receives a DCI whose CRC is scrambled with a CS-RNTI, and the HPN value of the received DCI corresponds to a specific SPS setting index or a group common SPS setting, the terminal can determine / judge that the PDSCH scheduled by the DCI retransmits the TB of the SPS PDSCH corresponding to the specific SPS setting index or the group common SPS setting.

[0503] When distinguishing SPS configuration index or group-common SPS configuration based on HPN, i.e., HARQ process ID, the base station needs to set different HARQ process numbers (e.g., nrofHARQ-Processes) and HARQ process ID-related offsets (e.g., harq-ProcID-Offset) for different SPS configurations or for terminal-dedicated SPS and group-common SPS configurations. That is, the base station sets the HARQ process number and HARQ process ID-related offset for each SPS configuration index, and the terminal can determine the HARQ process ID for a specific SPS transmission based on a specific formula (e.g., HARQ Process ID=[floor(CURRENT_slot*10 / (numberOfSlotsPerFrame*periodicity))] modulo nrofHARQ-Processes+harq-ProcID-Offset).

[0504] Alternatively, when multiple group common SPS configurations are configured / provided, or when both group common SPS configurations and UE-specific SPS configurations are configured / provided, the group common CS-RNTI and the unicast CS-RNTI may be configured separately. In this case, the group common SPS and the unicast SPS can overlap and share the same HARQ process ID.

[0505] Alternatively, the same CS-RNTI may be configured for the group-common SPS configuration and the UE-specific SPS configuration, and the CS-RNTI-based DCI may be configured / defined to distinguish between PTP retransmission and unicast transmission by including a new indicator. In this case, the new indicator of the DCI may indicate 1 bit or a group-common SPS configuration index.

[0506] Alternatively, the same CS-RNTI may be configured for the group-common SPS configuration and the UE-specific SPS configuration, and the group-common SPS and the UE-specific SPS may be distinguished by the HARQ process ID included in the CS-RNTI-based DCI. In this case, the group-common SPS and the unicast SPS need to use separate / distinguishable HARQ processes.

[0507] In this embodiment, in the above-mentioned manner, the terminal can receive the SPS (ie, the SPS PDSCH) as follows.

[0508] For example, an example of a UE-specific PDCCH activation command method for activating a group-common SPS may be as follows.

[0509] For example, the unicast SPS and the group common SPS may use the same CS-RNTI, and the DCI for SPS activation may indicate the group common SPS as 1-bit information. In this case, the HPN value of the activation DCI is not related to the SPS HARQ process ID actually used. In this case, the same SPS configuration index may be configured and used for both the group common SPS and the unicast SPS. That is, the UE may simultaneously activate the group common SPS and the unicast SPS having the same SPS configuration index. Furthermore, the activation DCI may indicate that the group common SPS and the unicast SPS having the same SPS configuration index are simultaneously activated, or may indicate that only the group common SPS or the unicast SPS is activated using the 1-bit information.

[0510] Alternatively, the unicast SPS and the group common SPS may use the same CS-RNTI, and the DCI for SPS activation may not include the 1-bit information. In this case, the HPN value of the activation DCI may be indicated to distinguish the unicast SPS and the group common SPS. For example, the unicast SPS and the group common SPS may be configured / defined to be mapped to different HPN values. In this case, the same SPS configuration index may not be mapped to the group common SPS and the unicast SPS at the same time, and may be mapped only to the group common SPS or the unicast SPS. The UE may simultaneously activate the group common SPS and the unicast SPS having the same SPS configuration index.

[0511] Alternatively, the unicast SPS and the group-common SPS may use different CS-RNTIs, and the DCI for SPS activation may not include the 1-bit information. In this case, the CS-RNTI value of the activation DCI may be indicated to distinguish the unicast SPS and the group-common SPS.

[0512] Additionally or alternatively, in different PDSCHs that may be transmitted in a cell such as that in FIG. 16, a case may be considered in which the HARQ-ACK for a unicast PDSCH is configured as a type 3 codebook, and the multicast PDSCH is configured as a type 1 codebook or a type 2 codebook.

[0513] In this case, the UE may construct / determine a type 3 codebook for HPN values ​​shared by unicast and multicast PDSCHs based on the following scheme.

[0514] In view of the above, an overriding method will be proposed in relation to a group common SPS in the present embodiment.

[0515] For example, after a specific group common SPS is activated by a DCI whose CRC is scrambled with a specific G-CS-RNTI, the terminal may store and decode a TB received through a group common SPS PDSCH in a HARQ process corresponding to a specific HPN value. Here, the specific HPN value is the same as a HARQ process ID corresponding to a group common SPS PDSCH resource. Then, the terminal may receive DCI whose CRC is scrambled with a terminal specific CS-RNTI or C-RNTI from the base station, or may receive DCI whose CRC is scrambled with the specific G-CS-RNTI.

[0516] If the received DCI indicates a retransmission resource and a specific HPN value, the UE may recognize the retransmission resource as a retransmission resource for a HARQ process corresponding to the indicated HPN value. Thus, the UE may store the HARQ process corresponding to the indicated HPN value for the TB received on the retransmission resource and re-decode the TB. In this case, the DCI for the UE specific CS-RNTI or C-RNTI may be used to allocate a PTP retransmission resource for the group common SPS, and the DCI for the specific G-CS-RNTI may be used to allocate a PTM retransmission resource for the group common SPS.

[0517] In the above method, a specific G-CS-RNTI and the terminal specific CS-RNTI may have a relationship as shown in the following example, and the relationship may be set by the base station or may be pre-defined (in terms of the standard).

[0518] As an example, a specific G-CS-RNTI may be mapped to a specific terminal-specific CS-RNTI by a base station configuration. As another example, a specific terminal-specific CS-RNTI may be mapped to all G-CS-RNTIs for group common SPS. As yet another example, when an SPS configuration index indicated by a DCI based on a specific terminal-specific CS-RNTI exists, a G-CS-RNTI concatenated with an SPS configuration index may be mapped to a specific terminal-specific CS-RNTI.

[0519] In relation to the above scheme, when a DCI whose CRC is scrambled in a C-RNTI indicates a specific HPN value used by a group common SPS of the G-CS-RNTI, the UE may determine that the DCI schedules a unicast PDSCH. In relation to this, a TB received via a unicast PDSCH may replace a TB stored in a HARQ process for the specific HPN value.

[0520] Alternatively, in relation to the above scheme, when a DCI whose CRC is scrambled in the C-RNTI indicates a specific HPN value used by the group common SPS of the G-CS-RNTI, the UE may determine that the DCI schedules a retransmission of the group common SPS PDSCH. In this regard, the UE may accumulate the TB received via the retransmission PDSCH in a TB stored in the HARQ process for the specific HPN value, and may re-decode the TB.

[0521] Additionally or alternatively, the case may be considered where, after multicast SPS activation, an FDMed unicast PDSCH and a multicast SPS PDSCH are scheduled in the same slot.

[0522] In the above case, if the terminal has the capability of receiving a unicast PDSCH and a multicast SPS PDSCH that are FDM-multiplexed, the terminal can process the unicast PDSCH and the multicast SPS PDSCH independently.

[0523] On the other hand, if the terminal is not capable of receiving a unicast PDSCH and a multicast SPS PDSCH that are FDM-multiplexed, the terminal can operate according to at least one of the following options (hereinafter, option 5-1 to option 5-4).

[0524] (Option 5-1) The terminal can receive a unicast PDSCH and drop multicast SPS PDSCH reception.

[0525] (Option 5-2) The terminal may receive one of the PDSCHs with a higher priority and drop the other (i.e., remaining) PDSCH reception with a lower priority, where the priority may be indicated by the DCI.

[0526] (Option 5-3) The terminal may not expect that the FDM unicast PDSCH and the multicast SPS PDSCH are scheduled in the same slot. In this case, the terminal may ignore reception of one or all of the PDSCHs.

[0527] (Option 5-4) The terminal may not expect a unicast PDSCH to override a multicast SPS PDSCH, in which case the terminal may ignore reception for one or all of the PDSCHs.

[0528] Additionally or alternatively, after multicast SPS activation, if a TDMed unicast PDSCH and a multicast SPS PDSCH are scheduled in the same slot, the terminal may operate according to at least one of the following options (hereinafter, options 5-5 to 5-7).

[0529] (Option 5-5) The terminal can process unicast PDSCH and multicast SPS PDSCH independently.

[0530] (Options 5-6) The terminal may not expect a TDM unicast PDSCH and a multicast SPS PDSCH to be scheduled in the same slot. In this case, the terminal may ignore reception for one or all of the PDSCHs.

[0531] (Options 5-7) The terminal may not expect a unicast PDSCH to override a multicast SPS PDSCH, in which case the terminal may ignore reception for one or all of the PDSCHs.

[0532] Additionally or alternatively, after activating the multicast SPS, if a PTP PDSCH retransmission and a multicast SPS PDSCH for the same G-RNTI or the same G-CS-RNTI or the same service are scheduled in the same slot, the terminal may operate according to at least one of the following options (hereinafter options 5-8 and 5-9).

[0533] (Options 5-8) The terminal can receive PTP PDSCH retransmissions and drop multicast SPS PDSCH reception. In this case, the terminal can ignore reception for one or all of the PDSCHs.

[0534] (Options 5-9) The terminal may not expect PTP PDSCH retransmissions to override multicast SPS PDSCHs for the same G-RNTI or G-CS-RNTI or service. In this case, the terminal may ignore reception of one or all of the PDSCHs.

[0535] Additionally or alternatively, after multicast SPS activation, if a PTP PDSCH retransmission and a multicast SPS PDSCH for different G-RNTIs or different G-CS-RNTIs or different services are scheduled in the same slot, the terminal may operate according to at least one of the following options (hereinafter, options 5-10 to 5-15).

[0536] (Options 5-10) The terminal can handle PTP PDSCH retransmissions and multicast SPS PDSCH independently.

[0537] (Options 5-11) The terminal can receive PTP PDSCH retransmissions and drop multicast SPS PDSCH reception.

[0538] (Options 5-12) The terminal may receive one of the PDSCHs with a higher priority and drop the other (i.e., remaining) PDSCH reception with a lower priority, where the priority may be indicated by the DCI.

[0539] (Options 5-13) The terminal may not expect FDMed PTP PDSCH retransmissions and multicast SPS PDSCHs to be scheduled in the same slot. In this case, the terminal may ignore reception for one or all of the PDSCHs.

[0540] (Options 5-14) The terminal may not expect PTP PDSCH retransmissions to override multicast SPS PDSCHs for different G-RNTIs or different G-CS-RNTIs or different services. In this case, the terminal may ignore reception of one or all of the PDSCHs.

[0541] (Options 5-15) The terminal can receive one of the PDSCHs with a lower RNTI and drop the other (i.e., remaining) PDSCHs with a higher RNTI, or vice versa, in which case the terminal can ignore reception of one or all of the PDSCHs.

[0542] Additionally or alternatively, a unicast / multicast dynamic DL grant may be sent to override the multicast SPS.

[0543] In this case, the terminal can expect to be able to override. In this regard, the override may always be possible if the priority of the DCI is HP (higher priority). Alternatively, the override may only be possible if the priority of the DCI is higher than the priority of the multicast SPS. Alternatively, the override may always be possible.

[0544] Meanwhile, the UE may expect that no override is possible. In this regard, the override may be possible as an exception for the FDM scheme depending on the UE capability. Alternatively, the override may always be impossible. Alternatively, the override may only be possible for the G-RNTI and G-CS-RNTI of the same service. In this case, the UE may not expect override for other services or may ignore DCI. Alternatively, the override may be possible for both the same or different services (e.g., RNTIs). Alternatively, the override may only be possible for different services (e.g., RNTIs).

[0545] Additionally or alternatively, a multicast dynamic DL grant may be sent to override a unicast SPS.

[0546] In this case, the terminal can expect to be able to override. In this regard, the override may always be possible if the priority of the DCI is HP (higher priority). Alternatively, the override may only be possible if the priority of the DCI is higher than the priority of the unicast SPS. Alternatively, the override may always be possible upon receipt of a multicast dynamic DL grant.

[0547] On the other hand, it is expected that the terminal cannot override the multicast dynamic DL grant. In this regard, the multicast dynamic DL grant may not override the unicast SPS. Thus, the terminal may receive only one of both or only the unicast SPS.

[0548] Hereinafter, a method for configuring / determining HARQ-ACK information (eg, HARQ-ACK codebook) for unicast / multicast transmission / reception as described above will be proposed.

[0549] FIG. 17 illustrates transmission and reception of unicast channels and multicast channels by FDM in a wireless communication system to which the present disclosure can be applied.

[0550] Referring to Figure 17, Figure 17(a) illustrates a case where unicast transmission and multicast transmission based on the same G-RNTI are FDM-multiplexed, and Figure 17(b) illustrates a case where unicast transmission and multicast transmission based on different G-RNTIs (e.g., two G-RNTIs) are FDM-multiplexed.

[0551] As shown in Figures 17(a) and 17(b), HARQ-ACK information for unicast and multicast transmissions may be transmitted / reported on the PUCCH.

[0552] In association with the HARQ-ACK information transmitted on the PUCCH, the HARQ-ACK codebook for unicast transmission and / or multicast transmission may be constructed / determined / generated based on at least one of the schemes in Table 8 below.

[0553] Table 8 shows a Type-1 HARQ-ACK codebook configuration scheme for multicast HARQ-ACK when a terminal receives multicast transmissions from multiple serving cells.

[0554] [Table 8-1] [Table 8-2]

[0555] According to the above-described embodiment of the present disclosure, for PTM transmission and PTP retransmission, a scheduled cell or a scheduling cell may support cross-carrier scheduling / intra-carrier scheduling (e.g., self-scheduling), which allows a base station to flexibly schedule group common transmission in a carrier aggregation (CA) situation.

[0556] In addition, according to the above-described embodiment of the present disclosure, there is an advantage in that the priority of PTP retransmission / unicast transmission for the same or different services is clarified and overriding of multicast SPS is enabled.

[0557] Apparatuses to which the present disclosure can be applied

[0558] FIG. 18 illustrates a block diagram of a wireless communication device according to an embodiment of the present disclosure.

[0559] Referring to FIG. 18, a first wireless device 100 and a second wireless device 200 can transmit and receive wireless signals using various wireless access technologies (eg, LTE, NR).

[0560] The 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 may be configured to control the memory 104 and / or the transceiver 106 to implement the descriptions, functions, procedures, suggestions, methods, and / or operational flow diagrams disclosed in the present disclosure. For example, the processor 102 may process information in the memory 104 to generate a first information / signal, and then transmit a wireless signal including the first information / signal from the transceiver 106. The processor 102 may also receive a wireless signal including a second information / signal from 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 coupled to the processor 102 and may store various information related to the operation of the processor 102. For example, the memory 104 may store software code including instructions for performing some or all of the processes controlled by the processor 102 or executing the descriptions, functions, procedures, suggestions, methods and / or operational flow diagrams disclosed in the present disclosure. 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 coupled 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 referred to as a Radio Frequency (RF) unit. In the present invention, a wireless device may mean a communication modem / circuit / chip.

[0561] The second wireless device 200 may include 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 may be configured to control the memory 204 and / or the transceiver 206 to implement the descriptions, functions, procedures, suggestions, methods, and / or operational flow diagrams disclosed in the present disclosure. For example, the processor 202 may process information in the memory 204 to generate a third information / signal, and then transmit a wireless signal including the third information / signal from the transceiver 206. The processor 202 may also receive a wireless signal including a fourth information / signal from the transceiver 206, and then store information obtained from signal processing of the fourth information / signal in the memory 204. The memory 204 may be coupled to the processor 202 and may store various information related to the operation of the processor 202. For example, the memory 204 may store software code including instructions for performing some or all of the processes controlled by the processor 202 or executing the descriptions, functions, procedures, suggestions, methods and / or operational flow diagrams disclosed in the present disclosure. Here, the processor 202 and the memory 204 may be part of a communication modem / circuit / chip designed to embody a wireless communication technology (e.g., LTE, NR). The transceiver 206 may be coupled 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 referred to as an RF unit. In the present invention, a wireless device may mean a communication modem / circuit / chip.

[0562] The hardware elements of the wireless device 100, 200 are described in more detail below. Without being limited thereto, one or more protocol layers may be embodied by one or more processors 102, 202. For example, one or more processors 102, 202 may embody 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, suggestions, methods, and / or operational flow diagrams disclosed in the present disclosure. One or more processors 102, 202 may generate messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods, and / or operational flow diagrams disclosed in the present disclosure. The one or more processors 102, 202 can generate and provide signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information to one or more transceivers 106, 206 according to the functions, procedures, suggestions, and / or methods disclosed in this disclosure. The one or more processors 102, 202 can receive signals (e.g., baseband signals) from the one or more transceivers 106, 206 and obtain the PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods, and / or operational flow diagrams disclosed in this disclosure.

[0563] The one or more processors 102, 202 may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. The one or more processors 102, 202 may be embodied in hardware, firmware, software, or a combination thereof. As an 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 the one or more processors 102, 202. The descriptions, functions, procedures, suggestions, methods, and / or operational flow diagrams disclosed in the present disclosure may be embodied using firmware or software, and the firmware or software may be embodied to include modules, procedures, functions, etc. Firmware or software configured to execute the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure may be included in one or more processors 102, 202 or stored in one or more memories 104, 204 and executed by one or more processors 102, 202. The descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure may be embodied in firmware or software in the form of code, instructions and / or collections of instructions.

[0564] 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 comprised of 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 internal and / or external to the one or more processors 102, 202. Also, the one or more memories 104, 204 may be coupled to the one or more processors 102, 202 by various techniques, such as wired or wireless coupling.

[0565] The one or more transceivers 106, 206 may transmit user data, control information, wireless signals / channels, etc., as referred to in the methods and / or operational flow diagrams of the present disclosure, to one or more other devices. The one or more transceivers 106, 206 may receive user data, control information, wireless signals / channels, etc., as referred to in the descriptions, functions, procedures, suggestions, methods and / or operational flow diagrams of the present disclosure, from one or more other devices. For example, the one or more transceivers 106, 206 may be coupled to one or more processors 102, 202 and may transmit and receive wireless signals. For example, the one or more processors 102, 202 may control the one or more transceivers 106, 206 to transmit user data, control information, or wireless signals to one or more other devices. Also, the one or more processors 102, 202 may control the one or more transceivers 106, 206 to receive user data, control information, or wireless signals from one or more other devices. In addition, one or more transceivers 106, 206 may be coupled to one or more antennas 108, 208, and the one or more transceivers 106, 206 may be configured to transmit and receive user data, control information, radio signals / channels, etc., as described, functions, procedures, suggestions, methods, and / or operation flow diagrams disclosed in the present disclosure, via the one or more antennas 108, 208. In the present disclosure, the one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). The one or more transceivers 106, 206 may convert the received radio signals / channels, etc., from RF band signals to baseband signals for processing the received user data, control information, radio signals / channels, etc., using one or more processors 102, 202. The one or more transceivers 106, 206 may convert the user data, control information, radio signals / channels, etc., processed using one or more processors 102, 202, from baseband signals to RF band signals. To that end, one or more of the transceivers 106, 206 may include (analog) oscillators and / or filters.

[0566] The above-described embodiments are combinations of the components and features of the present disclosure in a predetermined form. Each component or feature should be considered as optional unless otherwise expressly stated. Each component or feature may be implemented in a form not combined with other components or features. It is also possible to combine some components and / or features to configure the embodiments of the present disclosure. The order of operations described in the embodiments of the present disclosure may be changed. Some configurations or features of one embodiment may be included in another embodiment, or may be replaced with corresponding configurations or features of another embodiment. It is clear that claims that do not have an explicit reference relationship in the claims may be combined to configure an embodiment, or may be included as a new claim by amendment after filing.

[0567] It is obvious to those skilled in the art that the present disclosure can be embodied in other specific forms without departing from the essential features of the present disclosure. Therefore, the above detailed description should not be interpreted as limiting in any respect, but should be considered as illustrative. The scope of the present disclosure should be determined by a reasonable interpretation of the attached claims, and any modifications within the equivalent scope of the present disclosure are included in the scope of the present disclosure.

[0568] The scope of the present disclosure includes software or machine-executable instructions (e.g., operating systems, applications, firmware, programs, etc.) that cause a device or computer to perform operations according to the methods of the various embodiments, and non-transitory computer-readable media on which such software or instructions or the like can be stored and executed on a device or computer. Instructions available for programming a processing system to perform features described in the present disclosure may be stored on / in a storage medium or computer-readable storage medium, and computer program products including such storage media may be used to embody features described in the present disclosure. The storage medium may include high-speed random access memory, such as DRAM, SRAM, DDR RAM, or other random access solid-state memory devices, but is not limited thereto, and may include non-volatile memory, such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid-state storage devices. The memory optionally includes one or more storage devices that are located remotely from the processor. The memory or alternatively the non-volatile memory devices in the memory include non-transitory computer-readable storage media. The features described in this disclosure may be embodied in software and / or firmware stored on any one of a number of machine-readable media and capable of controlling the hardware of a processing system and allowing the processing system to interact with other mechanisms that utilize the results of embodiments of the present disclosure. Such software or firmware may include, but is not limited to, application code, device drivers, operating systems, and execution environments / containers.

[0569] Here, the wireless communication technology implemented in the wireless devices 100 and 200 of the present disclosure may include LTE, NR, and 6G as well as Narrowband Internet of Things (NB-IoT) for low power communication. At this time, for example, the NB-IoT technology may be an example of LPWAN (Low Power Wide Area Network) technology and may be implemented according to standards such as LTE Cat NB1 and / or LTE Cat NB2, and is not limited to the above names. Additionally or alternatively, the wireless communication technology implemented in the wireless devices 100 and 200 of the present disclosure may perform communication based on the LTE-M technology. At this time, as an example, the LTE-M technology may be an example of LPWAN technology and may be called various names such as eMTC (enhanced Machine Type Communication). For example, the LTE-M technology may be embodied by at least one of various standards such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL (non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine Type Communication, and / or 7) LTE M, and is not limited to the above names. Additionally or alternatively, the wireless communication technology embodied in the wireless devices 100 and 200 of the present disclosure may include at least one of ZigBee (registered trademark), Bluetooth (registered trademark), and Low Power Wide Area Network (LPWAN), which consider low power communication, and is not limited to the above names. As an example, the ZigBee technology may generate personal area networks (PANs) related to small / low power digital communication based on various standards such as IEEE 802.15.4, and may be called various names. [Industrial Applicability]

[0570] The method proposed in this disclosure has been described mainly as being applied to 3GPP LTE / LTE-A and 5G systems, but it can also be applied to various wireless communication systems other than 3GPP LTE / LTE-A and 5G systems.

Claims

1. 1. A method performed by a terminal in a wireless communication system, the method comprising: receiving a first downlink control information (DCI) indicating a new data indicator (NDI) value and a hybrid automatic repeat request (HARQ) process number value from a first cell; receiving a group-common physical downlink shared channel (PDSCH) scheduled by the first DCI in the first cell; receiving a second DCI indicating the NDI value and the HARQ process number value at a second cell; receiving, in the first cell, a terminal-dedicated PDSCH scheduled by the second DCI; The method according to claim 1, wherein the terminal dedicated PDSCH is determined and received as a retransmission of a transport block (TB) of the group common PDSCH based on a preset condition.

2. The method of claim 1 , wherein the first cell corresponds to a scheduled cell based on carrier aggregation (CA), and the second cell corresponds to a scheduling cell based on the CA.

3. The method of claim 2 , wherein the first cell corresponds to a secondary cell (SCell), and the second cell corresponds to either a primary cell (PCell) or a secondary cell (SCell).

4. The method of claim 1 , wherein the pre-set condition includes a case where cross-carrier scheduling for retransmission of the TB is set.

5. The method of claim 1 , wherein the predefined condition includes a common frequency resource (CFR) configuration associated with an active bandwidth part (BWP) of the first cell.

6. The method of claim 1 , wherein the second DCI further includes a carrier indicator field (CIF) indicating the first cell.

7. The method of claim 1 , wherein the first DCI is received by monitoring a common search space configured in the first cell.

8. The method of claim 1, wherein the second DCI is received by monitoring a user equipment-specific search space configured in the second cell.

9. 2. The method of claim 1, wherein the first DCI corresponds to a DCI format that is CRC (cyclic redundancy check) scrambled by a group-radio network temporary identifier (G-RNTI), and the second DCI corresponds to a DCI format that is CRC-scrambled by a common-radio network temporary identifier (C-RNTI).

10. The method according to claim 1 , wherein the transmission of the group-common PDSCH corresponds to an initial transmission of a PDSCH based on a group-common DCI.

11. A terminal in a wireless communication system, the terminal comprising: one or more transceivers; one or more processors coupled to the one or more transceivers; The one or more processors: receiving, at a first cell, a first DCI indicating an NDI value and a HARQ process number value; receiving, in the first cell, a group-common PDSCH scheduled by the first DCI; receiving, in a second cell, a second DCI indicating the NDI value and the HARQ process number value; Configuring the first cell to receive a terminal-dedicated PDSCH scheduled by the second DCI; The terminal determines and receives the terminal dedicated PDSCH as a retransmission of a transport block of the group common PDSCH based on a preset condition.

12. 1. A method performed by a network device in a wireless communication system, the method comprising: transmitting, in a first cell, a first DCI indicating an NDI value and a HARQ process number value; transmitting a group common PDSCH scheduled by the first DCI in the first cell; transmitting a second DCI indicating the NDI value and the HARQ process number value in a second cell; transmitting, in the first cell, a terminal-dedicated PDSCH scheduled by the second DCI; The method according to claim 1, wherein the terminal dedicated PDSCH is transmitted as a retransmission of a transport block of the group common PDSCH based on a preset condition.

13. A network device in a wireless communication system, the network device comprising: one or more transceivers; one or more processors coupled to the one or more transceivers; The one or more processors: Transmitting a first DCI in a first cell, the DCI indicating an NDI value and a HARQ process number value; Transmitting a group-common PDSCH scheduled by the first DCI in the first cell; transmitting a second DCI indicating the NDI value and the HARQ process number value in a second cell; Configuring the first cell to transmit a terminal-dedicated PDSCH scheduled by the second DCI; A network device, wherein the terminal dedicated PDSCH is transmitted as a retransmission of a transport block of the group common PDSCH based on a preset condition.

14. 1. A processing device configured to control a terminal in a wireless communication system, the processing device comprising: one or more processors; one or more computer memories operatively coupled to the one or more processors and storing instructions for performing operations based on being executed by the one or more processors; The operation includes: receiving, at a first cell, a first DCI indicating an NDI value and a HARQ process number value; receiving, in the first cell, a group-common PDSCH scheduled by the first DCI; receiving, in a second cell, a second DCI indicating the NDI value and the HARQ process number value; receiving, in the first cell, a terminal-dedicated PDSCH scheduled by the second DCI; A processing device for determining and receiving the terminal dedicated PDSCH as a retransmission of a transport block of the group common PDSCH based on a preset condition.

15. one or more non-transitory computer-readable media storing one or more instructions, The one or more instructions are executed by one or more processors, and a terminal in a wireless communication system comprises: receiving, at a first cell, a first DCI indicating an NDI value and a HARQ process number value; receiving, in the first cell, a group-common PDSCH scheduled by the first DCI; receiving, in a second cell, a second DCI indicating the NDI value and the HARQ process number value; Controlling reception of a terminal-dedicated PDSCH scheduled by the second DCI in the first cell; The computer-readable medium, wherein the terminal dedicated PDSCH is determined and received as a retransmission of a transport block of the group common PDSCH based on a preset condition.

Images