Method and apparatus for uplink communication in communication system supporting multiple panels

Abstract

A method and an apparatus for uplink communication in a communication system supporting multiple panels are disclosed. The method of the terminal comprises the steps of: receiving a first SSB from a first TRP; determining a first DL timing based on the first SSB; receiving a second SSB from the second TRP; determining a second DL timing based on the second SSB; receiving a PDCCH command from the first TRP; and transmitting the RA preamble to the second TRP based on the second DL timing when the first information element included in the PDCCH command indicates the second SSB or the second TRP.

Description

Technical Field

[0001] The present disclosure relates to communication technology, and more particularly to a technology for uplink communication of a terminal with multiple panels. Background Art

[0002] In order to cope with the growing demand for wireless data processing, a communication system (e.g., a New Radio (NR) communication system) is being considered that uses a frequency band (e.g., a frequency band above 6 GHz) higher than the frequency band of Long Term Evolution (LTE) (or LTE-A) (e.g., a frequency band below 6 GHz). The NR communication system can support frequency bands below 6 GHz and above 6 GHz, and can adapt to more diverse communication services and scenarios compared to the LTE communication system. For example, the use scenarios of the NR communication system may include enhanced mobile broadband (eMBB), ultra-reliable low latency communication (URLLC), and massive machine type communication (mMTC). Communication technology is required to meet the requirements of eMBB, URLLC, and mMTC.

[0003] At the same time, with the advancement of information and communication technologies, various wireless communication technologies are also continuously developing. Wireless communication technologies may include LTE and NR, as specified in the Third Generation Partnership Project (3GPP) standards. LTE may be one of the wireless communication technologies within the fourth generation (4G) wireless communication technology, while NR may be one of the wireless communication technologies within the fifth generation (5G) wireless communication technology. With the commercialization of 4G communication systems (e.g., communication systems supporting LTE technology), 5G communication systems (e.g., communication systems supporting NR technology) are being considered. In addition to using the sub-6 GHz frequency bands used by 4G communication systems, 5G communication systems also utilize higher frequency bands (e.g., above 6 GHz) to address the growing demand for wireless data processing. 5G communication systems may support eMBB, URLLC, mMTC, and / or time-sensitive communication (TSC) scenarios. Specifically, mMTC, URLLC, and / or TSC may be applied to Internet of Things (IoT) scenarios. A single communication network (e.g., a single communication system) may support all or some of the above scenarios. The mMTC scenario can meet the requirements of International Mobile Telecommunications (IMT)-2020 using narrowband (NB)-IoT and LTE-MTC. Technologies that meet the requirements of the URLLC scenario need to be developed. Summary of the Invention

[0004] Technical issues

[0005] The present disclosure aims to provide a method and apparatus for uplink communication of a terminal having multiple panels in a communication system.

[0006] Technical Solution

[0007] According to an exemplary embodiment of the present disclosure, a method of a terminal for achieving the above-mentioned purpose may include: receiving a first synchronization signal block (SSB) from a first transmission and reception point (TRP); determining a first downlink (DL) timing based on the first SSB; receiving a second SSB from a second TRP; determining a second DL timing based on the second SSB; receiving a physical downlink control channel (PDCCH) command from the first TRP; and in response to a first information element included in the PDCCH command indicating a second SSB or a second TRP, sending a random access (RA) preamble code to the second TRP based on the second DL timing.

[0008] The method may further include sending information indicating that the terminal supports two DL timings to at least one of the first TRP or the second TRP.

[0009] The first DL timing may be different from the second DL timing, and the difference between the first DL timing and the second DL timing may be equal to or less than a cyclic prefix (CP) or may exceed the CP.

[0010] A first timing advance (TA) between the terminal and the first TRP may be determined based on the first DL timing, and a second TA between the terminal and the second TRP may be determined based on the second DL timing.

[0011] The first information element may be information for selecting an SSB index indicating a second SSB or a physical cell identifier (PCI) indicating a second TRP.

[0012] The method may also include: receiving a medium access control (MAC) control element (CE) from the second TRP in response to the RA preamble code; and deriving at least one of a first TA between the terminal and the first TRP, a second TA between the terminal and the second TRP, or a TA command (TAC) based on information elements included in the MAC CE, wherein the first TA and the second TA belong to different TA groups (TAGs).

[0013] When uplink transmission to which the first TA or the second TA is applied is performed, a TAG identifier for determining the first TA or the second TA may be derived from spatial relationship information or transmission configuration indication (TCI) referenced by the uplink transmission.

[0014] The terminal may be two or more panels, a first communication between the terminal and a first TRP may be performed in a first panel among the two or more panels, and a second communication between the terminal and a second TRP may be performed in a second panel among the one or more panels.

[0015] According to an exemplary embodiment of the present disclosure, a method of a base station for achieving the above-mentioned purpose may include: sending a first synchronization signal block (SSB) through a first transmission and reception point (TRP) associated with the base station; sending a second SSB through a second TRP associated with the base station; sending a physical downlink control channel (PDCCH) command to a terminal through the first TRP; and receiving a random access (RA) preamble code from the terminal through the second TRP indicated by the PDCCH command.

[0016] The method may further include receiving, from the terminal through at least one of the first TRP or the second TRP, information indicating that the terminal supports two DL timings.

[0017] The first DL timing may be determined at the terminal based on the first SSB, the second DL timing may be determined at the terminal based on the second SSB, the first DL timing may be different from the second DL timing, and the difference between the first DL timing and the second DL timing may be equal to or less than a cyclic prefix (CP) or may exceed the CP.

[0018] A first timing advance (TA) between the terminal and the first TRP may be determined based on the first DL timing, and a second TA between the terminal and the second TRP may be determined based on the second DL timing.

[0019] The PDCCH command may include a first information element, and the first information element may be information for selecting an SSB index indicating a second SSB or a physical cell identifier (PCI) indicating a second TRP.

[0020] The method may further include sending a medium access control (MAC) control element (CE) through the second TRP in response to the RA preamble code, wherein the information elements included in the MAC CE can be used to derive at least one of a first TA between the terminal and the first TRP, a second TA between the terminal and the second TRP, or a TA command (TAC), and the first TA and the second TA may belong to different TA groups (TAGs).

[0021] When uplink transmission to which the first TA or the second TA is applied is performed, a TAG identifier for determining the first TA or the second TA may be derived from spatial relationship information or transmission configuration indication (TCI) referenced by the uplink transmission.

[0022] According to an exemplary embodiment of the present disclosure, a terminal for achieving the above-mentioned purpose may include at least one processor, and the at least one processor may enable the terminal to perform: receiving a first synchronization signal block (SSB) from a first transmission and reception point (TRP); determining a first downlink (DL) timing based on the first SSB; receiving a second SSB from a second TRP; determining a second DL timing based on the second SSB; receiving a physical downlink control channel (PDCCH) command from the first TRP; and in response to a first information element included in the PDCCH command indicating a second SSB or a second TRP, sending a random access (RA) preamble code to the second TRP based on the second DL timing.

[0023] The at least one processor may also cause the terminal to execute: sending information indicating that the terminal supports two DL timings to at least one of the first TRP or the second TRP.

[0024] The first DL timing may be different from the second DL timing, and the difference between the first DL timing and the second DL timing may be equal to or less than a cyclic prefix (CP) or may exceed the CP.

[0025] The first information element may be information for selecting an SSB index indicating a second SSB or a physical cell identifier (PCI) indicating a second TRP.

[0026] The at least one processor may also cause the terminal to perform: receiving a medium access control (MAC) control element (CE) from the second TRP in response to the RA preamble code; and deriving at least one of a first TA between the terminal and the first TRP, a second TA between the terminal and the second TRP, or a TA command (TAC) based on information elements included in the MAC CE, wherein the first TA and the second TA may belong to different TA groups (TAGs).

[0027] Beneficial effects

[0028] According to the present disclosure, a terminal can perform communication with multiple transmission and reception points (TRPs). The terminal can determine a first downlink (DL) timing based on a first SSB received from a first TRP, and determine a second DL timing based on a second SSB received from a second TRP. A first timing advance (TA) between the terminal and the first TRP can be determined based on the first DL timing, and a second TA between the terminal and the second TRP can be determined based on the second DL timing. The terminal can manage two TAs, thereby improving the communication performance between the terminal and multiple TRPs. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a conceptual diagram illustrating a first exemplary embodiment of a communication system.

[0030] Figure 2 is a block diagram illustrating a first exemplary embodiment of a communication node constituting a communication system.

[0031] Figure 3 is a conceptual diagram illustrating a first exemplary embodiment of SFN transmission.

[0032] Figure 4 is a conceptual diagram illustrating a second exemplary embodiment of SFN transmission.

[0033] Figure 5 is a conceptual diagram illustrating a first exemplary embodiment of SDM transmission.

[0034] Figure 6 is a conceptual diagram illustrating a second exemplary embodiment of SDM transmission.

[0035] Figure 7 is a conceptual diagram of a first exemplary embodiment showing events occurring in STxMP transmission.

[0036] Figure 8 is a conceptual diagram illustrating a first exemplary embodiment of a timing alignment method.

[0037] Figure 9 is a conceptual diagram illustrating a second exemplary embodiment of a timing alignment method.

[0038] Figure 10 is a conceptual diagram illustrating a third exemplary embodiment of a timing alignment method.

[0039] Figure 11 is a conceptual diagram illustrating a fourth exemplary embodiment of a timing alignment method.

[0040] Figure 12 is a conceptual diagram illustrating a first exemplary embodiment of a single-entry PHR MAC CE.

[0041] Figure 13 is a conceptual diagram illustrating a first exemplary embodiment of a multi-entry PHR MAC CE.

[0042] Figure 14 is a conceptual diagram illustrating a second exemplary embodiment of a multi-entry PHR MAC CE.

[0043] Figure 15 is a conceptual diagram illustrating a first exemplary embodiment of an improved single-entry PHR MAC CE.

[0044] Figure 16a and Figure 16b is a conceptual diagram illustrating a first exemplary embodiment of an improved multi-entry PHR MAC CE.

[0045] Figure 17a and Figure 17b is a conceptual diagram illustrating a second exemplary embodiment of an improved multi-entry PHR MAC CE.

[0046] Figure 18 is a conceptual diagram illustrating a first exemplary embodiment of an improved single-entry PHR MAC CE for multiple TRPs.

[0047] Figure 19 is a conceptual diagram illustrating a first exemplary embodiment of an improved multi-entry PHR MAC CE for multiple TRPs.

[0048] Figure 20 is a conceptual diagram illustrating a second exemplary embodiment of an improved multi-entry PHR MAC CE for multiple TRPs.

[0049] Figure 21 is a conceptual diagram illustrating a first exemplary embodiment of an SRS configuration based on Rel-15 NR technical specifications.

[0050] Figure 22 is a conceptual diagram illustrating a first exemplary embodiment of an SRS configuration based on Rel-16 NR technical specifications.

[0051] Figure 23 is a conceptual diagram illustrating a first exemplary embodiment of an SRS configuration based on the Rel-17 NR technical specification.

[0052] Figure 24 is a conceptual diagram illustrating a first exemplary embodiment of an SRS configuration considering a plurality of Tx panels.

[0053] Figure 25 is a conceptual diagram illustrating a first exemplary embodiment of an SRS configuration considering multiple TRPs and multiple Tx panels. DETAILED DESCRIPTION

[0054] Since the present disclosure may be modified and have various forms, specific exemplary embodiments will be shown in the drawings and described in detail in the detailed description. However, it should be understood that it is not intended to limit the present disclosure to specific exemplary embodiments, but on the contrary, the present disclosure covers all modifications and alternatives that fall within the spirit and scope of the present disclosure.

[0055] Relational terms such as "first," "second," and the like may be used to describe various elements, but these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, a first component may be named a second component, and a second component may be similarly named a first component, without departing from the scope of this disclosure. The term "and / or" refers to any one or a combination of multiple related and described items.

[0056] In exemplary embodiments of the present disclosure, “at least one of A and B” may refer to “at least one of A or B” or “at least one of a combination of one or more of A and B.” Furthermore, “one or more of A and B” may refer to “one or more of A or B” or “one or more of a combination of one or more of A and B.”

[0057] When a component is referred to as being “coupled” or “connected” to another component, it should be understood that the component is directly “coupled” or “connected” to the other component, or other components may be provided therebetween. Conversely, when a component is referred to as being “directly coupled” or “directly connected” to another component, it should be understood that no other components are provided therebetween.

[0058] The terms used in this disclosure are only used to describe specific exemplary embodiments and are not intended to limit the present disclosure. Unless the context clearly dictates otherwise, singular expressions also include plural expressions. In this disclosure, terms such as "including" or "having" are intended to indicate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but it should be understood that these terms do not exclude the presence or addition of one or more features, numbers, steps, operations, components, parts, or combinations thereof.

[0059] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Terms commonly used and included in dictionaries should be understood to have meanings consistent with the contextual meanings in the art. In this specification, unless explicitly defined, terms are not necessarily understood to have formal meanings.

[0060] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In describing the present disclosure, in order to facilitate overall understanding of the present disclosure, the same reference numerals refer to the same elements throughout the description of the accompanying drawings, and their repeated description will be omitted.

[0061] A communication system to which an exemplary embodiment of the present disclosure is applied will be described. The communication system to which the exemplary embodiment of the present disclosure is applied is not limited to the content described below, and the exemplary embodiment of the present disclosure can be applied to various communication systems. Here, the communication system can be used synonymously with the communication network.

[0062] In an exemplary embodiment, “configuration of an operation (e.g., a transmission operation)” may mean “signaling of configuration information (e.g., information element, parameter) for the operation” and / or “signaling of information instructing to perform the operation”. “Configuration of an information element (e.g., parameter)” may mean that the corresponding information element is signaled. The signaling may be at least one of: system information (SI) signaling (e.g., transmission of system information block (SIB) and / or master information block (MIB)), RRC signaling (e.g., transmission of RRC message, RRC parameters and / or higher layer parameters), MAC control element (CE) signaling (e.g., transmission of MAC message and / or MACCE), PHY signaling (e.g., transmission of downlink control information (DCI), uplink control information (UCI) and / or sidelink control information (SCI)), or a combination thereof.

[0063] Figure 1 is a conceptual diagram illustrating a first exemplary embodiment of a communication system.

[0064] refer to Figure 1 , the communication system 100 may include a plurality of communication nodes 110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5 and 130-6. In addition, the communication system 100 may further include a core network (e.g., a serving gateway (S-GW), a packet data network (PDN) gateway (P-GW) and a mobility management entity (MME). When the communication system 100 is a 5G communication system (e.g., an NR system), the core network may include an access and mobility management function (AMF), a user plane function (UPF), a session management function (SMF), etc.

[0065] The plurality of communication nodes 110 to 130 may support communication protocols defined by the technical specifications of the Third Generation Partnership Project (3GPP) (eg, LTE communication protocol, LTE-A communication protocol, NR communication protocol, etc.). The plurality of communication nodes 110 to 130 may support a communication protocol based on code division multiple access (CDMA), a communication protocol based on wideband CDMA (WCDMA), a communication protocol based on time division multiple access (TDMA), a communication protocol based on frequency division multiple access (FDMA), a communication protocol based on orthogonal frequency division multiplexing (OFDM), a communication protocol based on filtered OFDM, a communication protocol based on cyclic prefix OFDM (CP-OFDM), a communication protocol based on discrete Fourier transform spread OFDM (DFT-s-OFDM), a communication protocol based on orthogonal frequency division multiple access (OFDMA), a communication protocol based on single carrier FDMA (SC-FDMA), a communication protocol based on non-orthogonal multiple access (NOMA), a communication protocol based on generalized frequency division multiplexing (GFDM), a communication protocol based on filter bank multi-carrier (FBMC), a communication protocol based on universal filter multi-carrier (UFMC), a communication protocol based on spatial division multiple access (SDMA), etc. Each of the plurality of communication nodes may have the following structure.

[0066] Figure 2 is a block diagram illustrating a first exemplary embodiment of a communication node constituting a communication system.

[0067] refer to Figure 2 The communication node 200 may include at least one processor 210, a memory 220, and a transceiver 230 connected to a network to perform communication. In addition, the communication node 200 may further include an input interface device 240, an output interface device 250, a storage device 260, etc. The various components included in the communication node 200 may be connected via a bus 270 and communicate with each other.

[0068] However, each component included in the communication node 200 may be connected to the processor 210 through a separate interface or a separate bus instead of the common bus 270. For example, the processor 210 may be connected to at least one of the memory 220, the transceiver 230, the input interface device 240, the output interface device 250, and the storage device 260 through a dedicated interface.

[0069] The processor 210 can execute a program stored in at least one of the memory 220 and the storage device 260. The processor 210 may refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor, on which the method according to the embodiment of the present disclosure is executed. Each of the memory 220 and the storage device 260 can be composed of at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory 220 may include at least one of a read-only memory (ROM) and a random access memory (RAM).

[0070] Reference again Figure 1 , the communication system 100 may include multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2, and multiple terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6. Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 may constitute a macro cell, and each of the fourth base station 120-1 and the fifth base station 120-2 may constitute a small cell. The fourth base station 120-1, the third terminal 130-3, and the fourth terminal 130-4 may belong to the cell coverage of the first base station 110-1. In addition, the second terminal 130-2, the fourth terminal 130-4, and the fifth terminal 130-5 may belong to the cell coverage of the second base station 110-2. In addition, the fifth base station 120-2, the fourth terminal 130-4, the fifth terminal 130-5 and the sixth terminal 130-6 may belong to the cell coverage of the third base station 110-3. In addition, the first terminal 130-1 may belong to the cell coverage of the fourth base station 120-1, and the sixth terminal 130-6 may belong to the cell coverage of the fifth base station 120-2.

[0071] Here, each of the multiple base stations 110-1, 110-2, 110-3, 120-1 and 120-2 can refer to a Node-B, an evolved Node-B (eNB), a gNB, an advanced base station (ABS), a high reliability base station (HR-BS), a base transceiver station (BTS), a radio base station, a radio transceiver, an access point, an access node, a radio access station (RAS), a mobile multi-hop relay base station (MMR-BS), a relay station (RS), an advanced relay station (ARS), a high reliability relay station (HR-RS), a home NodeB (HNB), a home eNodeB (HeNB), a road side unit (RSU), a radio remote head (RRH), a transmission point (TP), a transmission and reception point (TRP), etc.

[0072] Each of the multiple terminals 130-1, 130-2, 130-3, 130-4, 130-5 and 130-6 can refer to a user equipment (UE), a terminal equipment (TE), an advanced mobile station (AMS), a high reliability mobile station (HR-MS), a terminal, an access terminal, a mobile terminal, a station, a subscriber station, a mobile station, a portable subscriber station, a node, a device, an on-board unit (OBU), etc.

[0073] In addition, each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can operate in the same frequency band or in different frequency bands. The multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can be connected to each other via an ideal backhaul or a non-ideal backhaul and exchange information with each other via the ideal backhaul or the non-ideal backhaul. In addition, each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can be connected to the core network via an ideal backhaul or a non-ideal backhaul. Each of the multiple base stations 110-1, 110-2, 110-3, 120-1 and 120-2 can send signals received from the core network to the corresponding terminal 130-1, 130-2, 130-3, 130-4, 130-5 or 130-6, and can send signals received from the corresponding terminal 130-1, 130-2, 130-3, 130-4, 130-5 or 130-6 to the core network.

[0074] In addition, each of the multiple base stations 110-1, 110-2, 110-3, 120-1 and 120-2 can support multiple-input multiple-output (MIMO) transmission (e.g., single-user MIMO (SU-MIMO), multi-user MIMO (MU-MIMO), massive MIMO, etc.), coordinated multi-point (CoMP) transmission, carrier aggregation (CA) transmission, unlicensed band transmission, device-to-device (D2D) communication (or proximity service (ProSe)), Internet of Things (IoT) communication, dual connectivity (DC), etc. Here, each of the multiple terminals 130-1, 130-2, 130-3, 130-4, 130-5 and 130-6 can perform operations corresponding to the operations of the multiple base stations 110-1, 110-2, 110-3, 120-1 and 120-2 (i.e., operations supported by the multiple base stations 110-1, 110-2, 110-3, 120-1 and 120-2). For example, the second base station 110-2 may transmit a signal to the fourth terminal 130-4 in SU-MIMO mode, and the fourth terminal 130-4 may receive a signal from the second base station 110-2 in SU-MIMO mode. Alternatively, the second base station 110-2 may transmit a signal to the fourth terminal 130-4 and the fifth terminal 130-5 in MU-MIMO mode, and the fourth terminal 130-4 and the fifth terminal 130-5 may receive a signal from the second base station 110-2 in MU-MIMO mode.

[0075] The first base station 110-1, the second base station 110-2, and the third base station 110-3 can transmit signals to the fourth terminal 130-4 in a CoMP transmission manner, and the fourth terminal 130-4 can receive signals from the first base station 110-1, the second base station 110-2, and the third base station 110-3 in a CoMP manner. In addition, each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can exchange signals with the corresponding terminal 130-1, 130-2, 130-3, 130-4, 130-5, or 130-6 within the coverage area of its cell in a CA manner. Each of base stations 110-1, 110-2, and 110-3 may control D2D communication between fourth terminal 130-4 and fifth terminal 130-5, and thus fourth terminal 130-4 and fifth terminal 130-5 may perform D2D communication under the control of second base station 110-2 and third base station 110-3.

[0076] The following describes the operation methods of communication nodes in a communication system. Even if a method (e.g., signal transmission or reception) performed at a first communication node among the communication nodes is described, a corresponding second communication node may also perform a method (e.g., signal transmission or reception) corresponding to the method performed at the first communication node. In other words, when the operation of a terminal is described, the corresponding base station may perform an operation corresponding to the operation of the terminal. Conversely, when the operation of a base station is described, the corresponding terminal may perform an operation corresponding to the operation of the base station.

[0077] The communication system may support multiple wireless communication technologies. The wireless communication technologies may include LTE communication technology and NR communication technology specified in the 3rd Generation Partnership Project (3GPP) standard. LTE communication technology may be one of the wireless communication technologies in the fourth generation (4G) wireless communication technology, and NR communication technology may be one of the wireless communication technologies in the fifth generation (5G) wireless communication technology.

[0078] With the commercialization of 4G communication systems (such as communication systems supporting LTE technology), people are considering 5G communication systems (such as communication systems supporting NR technology). In addition to using the frequency bands below 6 GHz used by 4G communication systems, 5G communication systems also use frequency bands higher than the frequency bands of 4G communication systems (such as frequency bands above 6 GHz) to cope with the growing demand for wireless data processing. 5G communication systems can support eMBB, URLLC, mMTC and / or time-sensitive communication (TSC) scenarios. Specifically, mMTC, URLLC and / or TSC can be applied to Internet of Things (IoT) scenarios. A single communication network (for example, a single communication system) can support all or part of the above scenarios. The mMTC scenario can use NB-IoT and LTE-MTC to meet the requirements of IMT-2020. Technologies that meet the requirements of URLLC scenarios need to be developed.

[0079] To reduce the error rate of the data, a lower modulation and coding scheme (MCS) level (or a lower MCS index) can be applied. In order not to increase the size of the field indicated by the downlink control information (DCI), a commonly used MCS can be selected. In order to apply a lower MCS, retransmission operations can be supported. When quadrature phase shift keying (QPSK) with the lowest modulation rate is applied, the code rate can be further reduced. Specifically, due to the limited transmit power in uplink (UL) transmission, retransmission operations can be performed in the time domain rather than the frequency domain.

[0080] For eMBB traffic and URLLC traffic, a lower MCS can be used for different purposes respectively. For example, for eMBB traffic, a lower MCS may be required to extend coverage. On the other hand, for URLLC traffic, a lower MCS may be required to reduce latency and achieve a lower error rate. Due to different requirements, eMBB traffic can be retransmitted even if a relatively large latency occurs. URLLC traffic can be transmitted using a new MCS (e.g., a lower MCS) instead of retransmitted. The new MCS can be configured through RRC messages and / or DCI.

[0081] To support retransmission of eMBB traffic in the time domain, physical uplink shared channel (PUSCH) repetition (e.g., PUSCH repetition type A) may be introduced. In the present disclosure, PUSCH repetition may refer to a PUSCH instance. In other words, depending on the context, PUSCH repetition may be interpreted as having the same meaning as a PUSCH instance. PUSCH retransmission may be performed in units of PUSCH instances. When performing PUSCH retransmission, PUSCH allocated on a slot basis may be retransmitted. To extend coverage, time resources may be allocated across multiple slots. When using PUSCH repetition type A, time resources may be configured via RRC messages and / or DCI. The number of PUSCH repetitions may be indicated via an RRC message, and the time resources used to transmit the PUSCH in the first slot may be indicated via DCI (e.g., in the case of a type 2 configuration grant (CG) or dynamic grant) or an RRC message (e.g., in the case of a type 1 CG). In the present disclosure, the number of repetitions may represent the number of retransmissions or the number of transmissions.

[0082] Since a delay time occurs when URLLC traffic is repeatedly transmitted, it may not be appropriate to repeatedly transmit URLLC traffic. However, if a sufficiently low MCS is used, the delay in decoding URLLC traffic can be reduced. That is, when a sufficiently low MCS is used, the number of resource elements (REs) to which URLLC traffic is mapped may increase, and the base station (e.g., a decoder of the base station) should wait until all REs are received. In this case, the delay in decoding URLLC traffic is reduced.

[0083] On the other hand, when a PUSCH with a slightly higher MCS applied is repeatedly transmitted, the base station can use only some REs to perform decoding operations. Therefore, the time when the decoding is first successful in repeated PUSCH transmissions (for example, repeated PUSCH transmissions with a slightly higher MCS applied) can be earlier than the time when the decoding is first successful in non-repeated PUSCH transmissions (for example, PUSCH transmissions with a low MCS applied). Since unnecessary delays may occur due to the use of PUSCH repetition type A, PUSCH repetition type B can be introduced to reduce the delay time due to retransmission. When PUSCH repetition type B is used, PUSCH allocated on a mini-slot basis can be repeatedly transmitted. When PUSCH repetition type B is used, time resources can be configured through RRC messages and / or DCI. The combination of reference time resources and number of repetitions for a PUSCH instance can be indicated by DCI (for example, type 2CG and / or dynamic grant) or RRC messages (for example, type 1CG).

[0084] In order to control the transmit power of the sounding reference signal (SRS) resource indicated by the SRS resource indicator (SRI), the base station may estimate the path loss for each SRS resource. The base station may use DCI to control the transmit power for the SRS resource. The transmit power of the SRS resource may be controlled based on the estimated path loss. The DCI may be a scheduling DCI (e.g., DCI format 0_0, DCI format 0_1, DCI format 0_2, DCI format 1_0, DCI format 1_1, or DCI format 1_2), or may be a group common (CG)-DCI (e.g., DCI format 2_2 or DCI format 2_3). The DCI may include a field indicating a transmit power control (TPC) command, and the TPC command may be used to control the transmit power of the terminal. For example, the transmit power of the terminal may be increased or decreased based on the TPC command included in the DCI. In order to determine the transmit power of the PUSCH, the terminal may consider a value obtained based on the path loss, a value according to the TPC command included in the DCI, and / or the PUSCH bandwidth indicated by the DCI.

[0085] The base station can configure two or more sets in the terminal using high-layer signaling. The terminal can receive configuration information of two or more sets from the base station. The elements constituting the two or more sets can be transmit power parameters and can be indicated as being applicable to different scenarios (e.g., URLLC scenarios, eMBB scenarios). The terminal can receive a scheduling DCI or activation DCI allocating PUSCH resources from the base station, which scheduling DCI or activation DCI can indicate a set for interpreting the transmit power parameters. If different transmit power parameter sets are used, the size of the increase or decrease in transmit power indicated by the same TPC command will be different.

[0086] When a Type 1 Configuration Grant (CG) or Type 2 CG is used, the transmit power may be determined based on DCI format 2_3 for the SRI associated with the PUSCH instance. When a Type 2 CG is used, the activation DCI may indicate a set of transmit power parameters applicable to the PUSCH opportunity. The PUSCH opportunity may refer to a PUSCH instance. The terminal may obtain a TPC command for the SRI by receiving GC-DCI, interpret the TPC command to fit the transmit power parameter set indicated by the base station, and derive the transmit power to be applied to the PUSCH instance based on the interpretation result.

[0087] In dynamically scheduled PUSCH transmissions, the terminal can derive the transmit power to be applied to the PUSCH instance based on a combination of GC-DCI and scheduling DCI. By receiving GC-DCI, the terminal can identify the TPC command corresponding to the SRI and store the identified TPC command. In dynamically scheduled PUSCH transmissions, the scheduling DCI can indicate a set of transmit power parameters and / or TPC commands applicable to the PUSCH occasion. The terminal can derive the transmit power to be applied to the PUSCH instance based on the transmit power of the SRI associated with the PUSCH instance.

[0088] Repeated HARQ-ACK transmissions can be indicated (or configured) by higher-layer signaling for each physical uplink control channel (PUCCH) format. The number of repetitions for PUCCH format i can be set independently. i can be 1, 3, or 4. The terminal can repeatedly transmit the PUCCH format in a time slot. In this case, the PUCCH format can be transmitted using the same time resources in each time slot.

[0089] Uplink control information (UCI) types can be classified according to the type of information included in the UCI. UCI may include at least one of a scheduling request (SR), layer 1 reference signal received power (L1-RSRP), HARQ-ACK, or channel state information (CSI). In an exemplary embodiment, "UCI" and "UCI type" may be used with the same meaning. In a retransmission operation of UCI, only one UCI type may be transmitted. To support this operation, a priority of UCI types may be defined in the technical specification. One UCI type may be selected, and a PUCCH including the one UCI type may be repeatedly transmitted. In this case, the terminal may assume that other UCI types are not transmitted until the transmission of the selected UCI type is completed. To support this operation, the base station may instruct the terminal to transmit UCI (e.g., SR or HARQ-ACK) after the PUCCH transmission is completed. The waiting time for transmitting UCI may be long, and the waiting time may become a scheduling constraint for the base station.

[0090] When HARQ-ACK is transmitted in the same time slot (or the same sub-time slot) or when the PUCCH time resources indicated by the DCI and / or the RRC message allocating the physical downlink shared channel (PDSCH) overlap with each other, the terminal can generate an HARQ codebook so that they are sent on one PUCCH (e.g., one PUCCH time resource). In the HARQ codebook, the HARQ-ACK bits can be arranged in the order defined in the technical specification. Information bits can be generated according to the above operation. The terminal can generate coded bits by performing a coding operation.

[0091] Reed-Muller codes or polar codes may be used in the coding operation. The code rate applied in the coding operation may be indicated by higher layer signaling. For example, one value in the PUCCH format may be the code rate and may be indicated to the terminal.

[0092] One codeword can be mapped to one PUCCH. In repeated PUCCH transmission operations, one UCI type can be generated as a codeword. When the PUCCH is sent once, the information bits of one UCI type or two or more UCI types can be concatenated, and the terminal can generate a codeword by performing the same coding operation on these information bits. When Reed-Muller code or polarization code is used, it may be difficult to perform soft combining operation and it is also difficult to implement. Therefore, even if the PUCCH is sent repeatedly, the same codeword can be sent, and the base station can perform a chase combining operation on the same codeword. A codeword or coded bit may refer to a bit string in which multiple code blocks are concatenated. A modulation operation can be performed on the codeword, and the result of the modulation operation can be mapped to RE.

[0093] In addition, UCI with the same UCI type can be considered as different information. UCI with the same UCI type, which is considered as different information, can be mapped. For example, UCI can be generated to support traffic with different priorities. UCI supporting eMBB traffic (e.g., SR or HARQ-ACK) can be considered as different information from UCI supporting URLLC traffic (e.g., SR or HARQ-ACK). In this case, information with the same UCI type can be distinguished as different information.

[0094] The coded UCI can be mapped to the PUCCH. The same pre-processing scheme (e.g., spatial information, spatial relationship) can be maintained during the PUCCH transmission operation. Alternatively, during the PUCCH transmission operation, base station signaling (e.g., RRC signaling) can allow the use of different pre-processing schemes for each PUCCH.

[0095] In order to support URLLC traffic, it may be preferred that the terminal performs frequent receiving operations in DL resources and / or performs frequent sending operations in UL resources. In a time division duplex (TDD) system, the terminal can perform operations based on a half-duplex scheme. Therefore, the support time of DL traffic and / or UL traffic can be increased according to the time slot mode. On the other hand, in a frequency division duplex (FDD) system, the terminal can utilize DL resources and UL resources at the same time. Therefore, the above-mentioned problems in the TDD system do not occur in the FDD system. The FDD system can use two or more carriers. When two or more serving cells are configured for the terminal in the TDD system, the terminal can use DL resources and UL resources.

[0096] In a communication system that includes at least one carrier employing FDD (hereinafter referred to as an "FDD carrier"), a terminal may not experience latency issues. However, in a communication system that includes only carriers employing TDD (hereinafter referred to as "TDD carriers"), a terminal may experience latency issues. To address these issues, time slots in a TDD carrier can be configured according to different modes.

[0097] The transmission of eMBB traffic and / or URLLC traffic can be supported in at least one of a licensed band or an unlicensed band. Carriers belonging to the licensed band can be used alone. Carriers belonging to the unlicensed band can be used alone. Alternatively, depending on the configuration of the base station, both carriers belonging to the licensed band and carriers belonging to the unlicensed band can be used based on a carrier aggregation scheme.

[0098] In an exemplary embodiment, two or more terminals may receive data from one or more TRPs and send data to one or more TRPs. It may be assumed that a base station or a server performs management operations and / or scheduling operations on one or more TRPs in a plurality of TRPs. The TRPs may be directly connected. Alternatively, the TRPs may be connected through a base station. The above connection may be a connection based on an Xn interface or a radio interface (e.g., a 3GPP NR interface).

[0099] Shadow areas may occur between coverage areas supported by TRPs. Therefore, TRPs can address shadow area issues through cooperative transmission. Cooperative transmission can be performed for terminals located between TRPs. Even if shadow areas do not occur, installing a large number of TRPs (or base stations) can transmit and receive large amounts of data, improving radio link quality.

[0100] According to the collaborative transmission and collaborative reception of TRP, the communication scheme can be divided into dynamic point selection (DPS) and joint transmission (JT). For a specific set of physical resource blocks (PRBs), DPS can be a method of receiving data through one TRP, and JT can be a method of receiving data through two or more TRPs. Dynamic point blanking (DPB) can be a type of JT. When DPB is used, the terminal may not be able to receive data from certain TRPs, but can receive data from the remaining TRPs. JT can be further divided into coherent JP and non-coherent JP. Depending on whether the coherent combining operation is performed on the signal received from the TRP, coherent JP or non-coherent JP can be used.

[0101] Depending on the latency and / or traffic quota of the base station or the backhaul to which the TRP is connected, the TRP may participate in collaborative transmission and / or collaborative reception in real time. Alternatively, depending on the latency and / or traffic quota of the base station or the backhaul to which the TRP is connected, the TRP may not be able to participate in collaborative transmission and / or collaborative reception in real time. The TRP may be connected (e.g., associated) to the same base station or different base stations. The terminal may support JT by receiving a single DCI (sDCI) or multiple DCIs (mDCI).

[0102] When using sDCI, the terminal can send and receive data with the TRP. The TRP can perform collaboration without delay through the backhaul. When using mDCI, the terminal can send and receive data with some TRPs and other TRPs. However, when it is difficult for the TRPs to collaborate in real time through the backhaul, the terminal can use semi-static resources (e.g., divided semi-static resources) to perform communication.

[0103] In order to distinguish TRPs, a control resource set (CORESET) pool index may be introduced. A CORESET pool index may indicate a group of CORESETs. The transmission configuration indication (TCI) status of each CORESET may be independently indicated to the terminal through signaling (e.g., RRC signaling and / or MACCE signaling). The CORESET pool index does not necessarily correspond to a TRP. The TRP may be divided into a transmission point (TxP) and a reception point (RxP), and the CORESET pool index may correspond to the RxP. For example, the Rx beam of a terminal receiving a DL signal / channel from a TxP may be derived from the TCI status, while a DCI-scheduled UL signal / channel detected by a CORESET belonging to a CORESET pool corresponding to one CORESET pool index may be interpreted as being received from the same RxP. In the present disclosure, "DL signal / channel" may refer to "DL signal and / or DL channel", and "UL signal / channel" may refer to "UL signal and / or UL channel".

[0104] When synchronization between TRPs is achieved and CSI reports are shared between TRPs, performance gains may occur due to coherent combining operations performed in the terminal. When the above conditions are not met, performing non-coherent combining operations in the terminal may be more advantageous in terms of performance.

[0105] When the terminal is mounted on a vehicle, there may be fewer restrictions on the size and / or weight of the terminal.For terminals intended for direct human use, portability may be a consideration.

[0106] In order to expand the coverage, small cells or IAB nodes can be deployed in the communication system. The throughput of small cells or IAB nodes may be affected by the quality of the backhaul. Ensuring a backhaul (e.g., high-quality backhaul) may be costly. As an alternative to the above problem, wireless repeaters can be deployed in the communication system, and high-quality signals can be sent to the terminal through the wireless repeaters. According to the scheme for transmitting signals, wireless repeaters can be divided into several types. Wireless repeaters that support multiple functions can provide performance similar to that of base stations. When wireless repeaters that support fewer functions are deployed, a communication system including wireless repeaters can be built at a low cost. In the present disclosure, the wireless repeater can support the beamforming function of the terminal and the minimum function for transmitting data to the terminal. The base station can send a signal / channel to control the wireless repeater. The wireless repeater can receive a signal / channel (e.g., a control signal / control channel) from the base station and configure appropriate parameters based on the received signal / channel. In other words, the base station can configure the wireless repeater with appropriate parameters to control the wireless repeater.

[0107] The terminal can use multiple panels (e.g., multiple Tx panels) to send UL signals / channels. The terminal can perform simultaneous transmission (STxMP) across multiple UE panels. The exemplary embodiments of the present disclosure will focus on describing the PUSCH transmission method, but these exemplary embodiments can be equally or similarly applied to the transmission of other UL signals / channels (e.g., SRS, PUCCH). The Tx panel can be referred to as an antenna group or an antenna port group. An antenna port group (e.g., an antenna group) can include two or more antenna ports. The consistency of antenna ports belonging to the same antenna port group (e.g., phase continuity and / or power consistency) can be maintained.

[0108] The scheduling information of PUSCH (e.g., DCI) can indicate the SRS resources to the terminal. In other words, the DCI may include an SRS resource indicator (SRI). The terminal may use one Tx panel or multiple Tx panels to send SRS in the SRS resources indicated by the SRI. In the present disclosure, depending on the context, a Tx panel or panel may be interpreted as a Tx panel of the terminal. Multiple Tx panels may be used simultaneously to send SRS. When an SRS port or a DM-RS port is used as a radio resource, SRS transmission or DM-RS transmission may be performed regardless of the Tx panel. The terminal may perform SRS transmission or DM-RS transmission based on STxMP. Alternatively, the terminal may use one Tx panel to perform SRS transmission or DM-RS transmission.

[0109] The terminal may send UE capability information to the base station, which includes information indicating that the terminal supports STxMP. The base station may identify the terminal's support for STxMP through UE capability signaling. In this case, the base station may indicate two or more SRS resource sets to the terminal through signaling (e.g., RRC signaling). The terminal may identify the SRS resource set indicated by the base station. Each SRS resource set may include one or more SRS resources. An SRS resource set may correspond to one Tx panel of the terminal.

[0110] For example, in codebook-based PUSCH transmission, one SRS resource may correspond to a radio link from the terminal's Tx panel to the RxP. When a base station uses multiple RxPs, the base station may indicate an SRS resource set including multiple SRS resources to the terminal through signaling (e.g., RRC signaling). The terminal may derive the number of PUSCH DM-RS ports based on the number of SRS resource ports indicated by the base station. The port of an SRS resource (e.g., the port owned by the SRS resource) may refer to an SRS port.

[0111] For example, in non-codebook-based PUSCH transmission, the SRS resource may correspond to a Tx beam of a radio link from a Tx panel of a terminal to an RxP. The number of ports owned by each SRS resource may be one.

[0112] The terminal may receive signaling (e.g., RRC signaling) indicating an SRS resource set from the base station. The SRS resource set may be referred to as the QC1 or TCI state of the Tx beam used to transmit the PUSCH. One TCI state, or two or more TCI states, of the PUSCH may be indicated to the terminal. When the PUSCH is transmitted to two or more RxPs based on a time division multiplexing (TDM) scheme, each of the two or more TCI states (or one TCI state) may correspond to a Tx beam of the radio link for each RxP.

[0113] One transmit precoding matrix indicator (TPMI) or two or more TPMIs may be indicated to the terminal. When the PUSCH is transmitted to two or more RxPs based on the TDM scheme, each of the two or more TPMIs (or one TPMI) may correspond to a Tx beam of a radio link for each RxP.

[0114] 1. PUSCH transmission method using STxMP in a single layer

[0115] Discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-s-OFDM) or cyclic prefix (CP)-OFDM can be applied to PUSCH transmission. When PRBs are continuously allocated and DFT precoding is additionally applied, single carrier characteristics appear, so the peak-to-average power ratio (PAPR) / cubic metric (CM) may be reduced. Taking into account the implementation complexity of the continuously allocated PRBs and the DFT precoding engine, it is preferred that the number of PRBs meets a multiple of 2, 3 or 5. DFT-s-OFDM is mainly used in coverage edge areas. That is, DFT-s-OFDM can be used when one DM-RS port is used. Even in the coverage edge area, CP-OFDM can be applied according to the instructions of the base station, and in this case, there is no restriction on the allocation of PRBs and / or the number of DM-RS ports.

[0116] When the number of DM-RS ports for PUSCH transmission is one, DFT-s-OFDM can be applied. In this case, when the terminal has two or more DM-RS ports, CP-OFDM can be applied without separate signaling. In PUSCH transmission using STxMP, two or more DM-RS ports can be used. Therefore, even if one DM-RS port is used in each Tx panel, DFT-s-OFDM may not be applied.

[0117] Method 1-1: DFT-s-OFDM may not be applicable to PUSCH transmission using STxMP.

[0118] In the present disclosure, PUSCH transmission using STxMP may be referred to as "STxMP PUSCH transmission". Alternatively, DFT-s-OFDM may be applied to STxMP PUSCH transmission depending on UE capabilities. A terminal supporting STxMP may apply a DFT precoding engine to each Tx panel. For example, the terminal may sequentially apply a DFT precoding engine to two or more Tx panels by reusing the same DFT precoding engine in time. For another example, the terminal may apply the DFT precoding engine to the corresponding Tx panel.

[0119] The terminal may apply one DFT precoding engine to one Tx panel according to UE capabilities (e.g., specific UE capabilities). In this case, when STxMP is configured in the terminal, the terminal may not be able to transmit a PUSCH to which DFT-s-OFDM is applied. Alternatively, according to UE capabilities (e.g., other UE capabilities), DFT precoding may be applied even if STxMP is configured in the terminal, so the terminal may be able to transmit a PUSCH to which DFT-s-OFDM is applied.

[0120] Method 1-2: Depending on UE capabilities, DFT-s-OFDM can be applied to STxMP PUSCH transmission.

[0121] The terminal can support STxMP using sDCI or mDCI. Depending on the method of using sDCI, when the number of DM-RS ports is 2 or more, the terminal can send PUSCH with CP-OFDM applied. When the number of DM-RS ports is 1 (for example, when PUSCH is allocated by a fallback DCI format, when DFT-s-OFDM is indicated in the UL bandwidth part (BWP), or when the scheduling DCI indicates the application of DFT-s-OFDM), the terminal can send PUSCH with DFT-s-OFDM applied.

[0122] Method 1-3: When the sDCI mode is supported (eg, when sDCI is used), the terminal may not apply DFT-s-OFDM to STxMP PUSCH transmission.

[0123] The terminal may transmit a PUSCH in sDCI mode, and two or more TRPs may receive the PUSCH. The terminal may receive an indication or configuration for an SRS resource set and a second SRS resource set (or a first SRS resource set and a second SRS resource set). Scheduling information including a separate TPMI / RI, TPC parameter set, TPC command, SRI, and / or UL / Joint TCI may be indicated or configured for each SRS resource set.

[0124] PUSCH transmission may be performed in a first time resource using scheduling information associated with a first SRS resource set. PUSCH transmission may be performed in a second time resource using scheduling information associated with a second SRS resource set. In subsequent time resources, the same method as described above may be applied such that scheduling information associated with SRS resource sets may be alternately used for PUSCH transmission.

[0125] Alternatively, PUSCH transmission may be repeatedly performed using scheduling information associated with the first SRS resource set. Thereafter, PUSCH transmission may be repeatedly performed using scheduling information associated with the second SRS resource set.

[0126] When the backhaul connection delay between TRPs (or base stations) is large, real-time collaboration between TRPs (or base stations) may be more difficult. In this case, mDCI can be used. When the DCI sent from one TRP allocates PUSCH to the terminal, and the DCI sent from another TRP also allocates PUSCH to the terminal, the terminal can perform STxMP PUSCH transmission by applying a Tx beam (or TPMI) pointing to each TRP (or RxP). In this case, since the DM-RS port for each DCI included in the mDCI can be allocated to the terminal, the terminal can use two or more DM-RS ports to perform PUSCH transmission.

[0127] One TRP can schedule PUSCH transmission by using both fallback and non-fallback DCI formats, while another TRP can schedule PUSCH transmission using only non-fallback DCI formats. In this case, in STxMP PUSCH transmission, the terminal transmits PUSCH to which DFT-s-OFDM is applied through one Tx panel and can transmit PUSCH to which CP-OFDM is applied through another Tx panel.

[0128] Method 1-4: When the mDCI mode is supported (eg, when mDCI is used), the terminal may apply DFT-s-OFDM to STxMP PUSCH transmission.

[0129] The TRPs that can use the fallback DCI format can be serving TRPs, and these TRPs can be TRPs that use a type 1 RACH process to connect to the base station without separate signaling (e.g., RRC signaling). The TRPs that can use the fallback DCI format can be indicated to the terminal by signaling (e.g., RRC signaling). The TRPs that can use the fallback DCI format can be TRPs that send the DCI format in the CORESET with the CORESET pool index 0. The search space and CORESET that can receive the fallback DCI format can be limited to the CORESET with a specific CORESET pool index.

[0130] Method 1-5: The search space associated with the fallback DCI format may be associated with a specific CORESET (eg, a CORESET with a specific CORESET pool index).

[0131] 2. PHY processing method based on STxMP mode

[0132] A transmission scheme configurable for a terminal in STxMP PUSCH transmission will be described. The exemplary embodiments of the present disclosure will focus on describing a terminal having two Tx panels (e.g., Tx panel 0, Tx panel 1), but the exemplary embodiments may be equally or similarly applied to a terminal having two or more Tx panels.

[0133] The terminal's Tx panel can be associated with an SRS resource set. The PUSCH transmission scheme can be indicated to the terminal via signaling (e.g., RRC signaling). Transmission schemes can be categorized as single frequency network (SFN) or spatial domain multiplexing (SDM). The base station can configure either the SFN or SDM transmission scheme for the terminal.

[0134] The terminal may transmit a PUSCH allocated by a non-fallback DCI format (e.g., DCI format 0_1, DCI format 0_2, etc.). In this case, the terminal may perform PUSCH transmission based on one of the SFN transmission scheme, the SDM transmission scheme, or other transmission schemes. Transmission of a PUSCH scheduled by a fallback DCI format may be performed based on a separate transmission scheme.

[0135] Figure 3 is a conceptual diagram illustrating a first exemplary embodiment of SFN transmission.

[0136] refer to Figure 3 , the base station may indicate the SFN transmission scheme to the terminal (e.g., UL transmission based on the SFN transmission scheme). Multiple DM-RS ports may be indicated to the terminal. The terminal may perform PUSCH transmission based on multiple DM-RS ports. In codebook-based transmission, a Tx beam for a DM-RS port may be determined using one SRI belonging to the same SRS resource set, and a transmit rank indicator (TRI) and a TPMI may be applied to each Tx beam. In non-codebook-based transmission, each Tx beam may be determined using one or more SRIs belonging to the same SRS resource set (e.g., an SRI corresponding to a TRI), and a separate TPMI is not applied to each Tx beam.

[0137] Different coded bits can be mapped to each layer (or DM-RS port). Table 1 below shows the mapping of codewords to layers for spatial multiplexing. In other words, Table 1 below shows a method of mapping one codeword to 1, 2, 3, or 4 layers to perform PUSCH transmission. d(·) may represent one coded bit as a result of a low-density parity check (LDPC) encoding operation. x(·) may represent a bit mapped to a layer. TPMI may be applied before the mapping operation for the DM-RS port. Alternatively, the same Tx beam as SRI may be applied.

[0138] [Table 1]

[0139]

[0140] In codebook-based transmission, the available TPMI may vary depending on the codebook subset (e.g., fullyAndPartialAndNonCoherent, partialAndNonCoherent, or noncoherent). The terminal may select a TPMI from the available TPMIs (e.g., allowed TPMIs) based on a specific field included in the UL-DCI. The UL-DCI may be a DCI that schedules UL transmission. DM-RS ports 0 and 2 may be a coherent pair, and DM-RS ports 1 and 3 may be another coherent pair. When the terminal has two Tx panels and consistency is not maintained between the two Tx panels, it may be preferable for the terminal to assign even-numbered DM-RS ports and odd-numbered DM-RS ports to different Tx panels.

[0141] When the terminal is instructed to perform SFN transmission (e.g., SFN transmission scheme), the terminal can transmit the same coded bits in each Tx panel. The same coded bits can be mapped to all DM-RS ports. Table 2 below shows the mapping of codewords to layers for SFN transmission. Referring to Table 2 below, coded bits can be mapped to layers, and layers can be mapped to DM-RS ports.

[0142] After the mapping of codewords to layers, a separate TPMI or SRI included in the SRS resource set can be applied to each TX panel. Alternatively, one TPMI can be applied to all Tx panels. Figure 3 In an exemplary embodiment of the present invention, DM-RS ports 0 and 2 may correspond to Tx panel 0, and DM-RS ports 1 and 3 may correspond to Tx panel 1.

[0143] [Table 2]

[0144]

[0145] Figure 3 In an exemplary embodiment, the SRS resources selected from each SRS resource set (e.g., SRS resource set 0 or SRS resource set 1) may have the same number of ports. In codebook-based transmission, the number of SRIs may be 1, and the number of DM-RS ports may be the same as the number of SRS ports. In non-codebook-based transmission, the number of SRS ports may be 1, and the number of SRIs may be the same as the number of DM-RS ports.

[0146] When the SRS ports for an SRS resource are 1000, 1001, ..., 1000+TRI-1, the same coded bits can be mapped to the DM-RS port corresponding to the same SRS port of the SRS resource. Each SRS port can be mapped to a different DM-RS port. The above mapping relationship can be applied to codebook-based transmission.

[0147] When two or more SRS resources are selected using SRIs, the order of the SRIs belonging to each SRS resource set may correspond to the relative order of the DM-RS ports. The number of SRIs selected from each SRS resource set may be the same. The number of SRS resources included in an SRS resource set may always be the same. Alternatively, the number of SRS resources included in an SRS resource set may be different.

[0148] SRIs with relative order can be associated with the same coded bits. The above association relationship can be applied to non-codebook based transmission.

[0149] Table 3 below shows an SRI indication for non-codebook-based PUSCH transmission. In other words, Table 3 below shows a method for interpreting the SRI field included in the UL-DCI. Table 4 below shows a second SRI indication for non-codebook-based PUSCH transmission. In other words, Table 4 below shows a method for interpreting the second SRI field included in the UL-DCI. The terminal may consider a case where the SRS resource set includes 4 SRS resources. In other words, N SRS It can be 4. N SRS The number of SRS resources can be indicated. A maximum of two DM-RS ports can be indicated to the terminal. In other words, L max It can be 2. L max The maximum number of configurable DM-RS ports (e.g., layers) in the terminal can be indicated. Each of the SRI field and the second SRI field can indicate an SRS resource selected from an SRS resource set. The SRI field and the second SRI field can indicate the same number of indexes. For example, when the SRI field indicates indexes 0 to 3 (e.g., 4 indexes), the second SRI field can indicate indexes 0 to 3 (e.g., 4 indexes). When the SRI field indicates indexes 4 to 9 (e.g., 6 indexes), the second SRI field can indicate indexes 0 to 5 (e.g., 6 indexes). SRIs with the same relative order (e.g., SRIs in the first SRS resource set and SRIs in the second SRS resource set) can correspond to different DM-RS ports, and different DM-RS ports can correspond to the same coded bits.

[0150] [Table 3]

[0151]

[0152] [Table 4]

[0153]

[0154] Method 2-1: When the terminal is instructed to perform SFN transmission (e.g., SFN transmission scheme), and the port corresponding to the SRS resource selected from the first SRS resource set and the port corresponding to the SRS resource selected from the second SRS resource set are the same, the same coded bits can be mapped to the port associated with each SRS resource set. Each port of the SRS resource can be mapped to a different DM-RS port.

[0155] Figure 4 is a conceptual diagram illustrating a second exemplary embodiment of SFN transmission.

[0156] refer to Figure 4 , multiple DM-RS ports can be indicated to the terminal, and the terminal can perform PUSCH transmission based on the multiple DM-RS ports.

[0157] When the SRS port of an SRS resource is 1000, 1001, ..., and 1000+TRI-1, the same coded bit can be mapped to the DM-RS port corresponding to the same SRS port of the SRS resource. The Tx panel of the terminal can be mapped to the same DM-RS port. The terminal can perform PUSCH transmission using the Tx panel sharing the same DM-RS port. The base station can receive the PUSCH DM-RS from the terminal, estimate the effective channel response based on the PUSCH DM-RS, and decode the data (e.g., PUSCH) based on the estimated channel response. In the present disclosure, the PUSCH DM-RS can be a DM-RS for demodulating and / or decoding the PUSCH.

[0158] When an SRI selects two or more SRS resources, the order of the SRIs belonging to each SRS resource set may correspond to the relative order of the DM-RS ports. The number of SRIs selected from each SRS resource set may be the same. Each SRS resource set may include the same number of SRS resources. Alternatively, each SRS resource set may include a different number of SRS resources.

[0159] SRIs with relative order can be associated with the same coded bits. The above association relationship can be used for non-codebook based transmission.

[0160] The SRI field in Table 3 and the second SRI field in Table 4 may indicate the same number of indexes. The relative order of the indexes indicated by each of the SRI field and the second SRI field may be maintained, and each of the SRI field and the second SRI field may correspond to the same DM-RS port.

[0161] Method 2-2: When the terminal is instructed to perform SFN transmission (e.g., SFN transmission mode), and the SRS resources selected from each SRS resource set correspond to the same DM-RS port, the same coded bits can be mapped to the port (e.g., DM-RS port). Each SRS resource port can be mapped to the same DM-RS port.

[0162] In the above method, a DM-RS port can be mapped to one or more SRS resources. Here, the SRS port can be used to represent the Tx beam of the PUSCH (or PUCCH), while the DM-RS port can be used for data mapping and channel estimation of the PUSCH (or PUCCH).

[0163] The terminal can perform an operation of mapping as many coded bits as the number of Tx panels to layers. The operation of mapping coded bits to layers can be performed independently. For example, when the terminal has two Tx panels, the mapping operation according to Table 1 can be repeated twice. When the number of ports used by the terminal for transmission is limited to 4, according to Table 1, the coded bits can be mapped to a maximum of two layers. To describe the above operation, the following Table 5 can be considered. Table 5 shows the mapping of codewords to layers for SFN transmission. The transmission output of Tx panel 0 can be referred to as x ， The transmission output of Tx Panel 1 can be called y. The transmission input of Tx Panel 0 and Tx Panel 1 can be called d.

[0164] One TPMI can be applied to all Tx panels. Alternatively, a separate TPMI or SRI included in the SRS resource set can be applied to each Tx panel. In this case, Figure 4 In an exemplary embodiment, DM-RS ports 0, 1, 2, and 3 may correspond to each Tx panel.

[0165] [Table 5]

[0166]

[0167] Figure 5 is a conceptual diagram illustrating a first exemplary embodiment of SDM transmission.

[0168] refer to Figure 5, different coded bits can be mapped to each Tx panel. In codebook-based PUSCH transmission, one Tx panel can correspond to one SRS resource set. Therefore, a common TPMI can be applied to the DM-RS ports corresponding to the SRS resources belonging to the same SRS resource set (e.g., DM-RS ports 0 and 2, or DM-RS ports 1 and 3). TPMI (e.g., common TPMI) can be applied even when the number of Tx panels in PUSCH transmission is interpreted as one instead of multiple. In STxMP PUSCH transmission, two TPMIs can be indicated to the terminal, and when the terminal uses one Tx panel, one TPMI can be indicated to the terminal. The above operation can be applied when the sDCI mode is used in the mTRP scenario.

[0169] Figure 6 is a conceptual diagram illustrating a second exemplary embodiment of SDM transmission.

[0170] refer to Figure 6 , a different codeword can be mapped to each Tx panel (or DM-RS port corresponding to an SRS resource set). When transmission is performed using four or fewer layers, one codeword can be mapped. In the proposed method, even if transmission is performed using four or fewer layers, two codewords can be mapped according to the number of Tx panels.

[0171] Method 2-3: When the terminal is instructed to perform SDM transmission (eg, SDM transmission scheme), different coded bits may be mapped in each SRS resource set.

[0172] In STxMP PUSCH transmission, a maximum of 4 layers (or DM-RS ports) can be supported, and the number of layers L used for transmission in each Tx panel shall not be greater than 4. In other words, when the L1 layer is used for transmission in the first SRS resource set, L2 (=L-L1) or fewer layers can be used for transmission in the second SRS resource set.

[0173] For example, L1 can be 0, 1, 2, or 3, L2 can be less than or equal to L-L1, and L2 can be 0, 1, 2, or 3. In this case, a separate TPMI can be indicated for each Tx panel. Alternatively, one TPMI can be indicated to the terminal, and the terminal can apply the one TPMI to all Tx panels.

[0174] Method 2-4: In method 2-3, a combination of L1 and L2 that satisfies the condition of L1+L2 is allowed.

[0175] As another example, L1 may be 0, 1, or 2. L2 may be less than or equal to L-L1, and L2 may be 0, 1, or 2. In this case, a separate TPMI may be indicated for each Tx panel, and the terminal may apply the separate TPMI to each Tx panel.

[0176] Method 2-5: In method 2-3, a combination of L1 and L2 that satisfies the L1+L2 condition and all conditions of L1 and L2 is allowed.

[0177] When the mDCI mode is indicated in the mTRP scenario, the terminal can transmit the PUSCH scheduled by one TRP and the PUSCH scheduled by another TRP by using different Tx panels. Figure 6 As shown in the exemplary embodiments, different layers can be mapped to PUSCH transmission.

[0178] The base station can instruct the terminal to perform STxMP PUSCH transmission or non-STxMP PUSCH transmission (e.g., TDM PUSCH transmission) through signaling (e.g., RRC signaling). The terminal can identify the transmission (e.g., STxMP PUSCH transmission or non-STxMP PUSCH transmission) indicated by the signaling (e.g., RRC signaling) of the base station. Non-STxMP PUSCH transmission may refer to non-STxMP-based PUSCH transmission. TDM PUSCH transmission may refer to TDM-based PUSCH transmission.

[0179] STxMP PUSCH transmission can be performed based on the SFN transmission mode or the SDM transmission mode. The base station can indicate the transmission mode for STxMP PUSCH transmission to the terminal through signaling. The terminal can recognize the transmission mode (e.g., SFN transmission mode or SDM transmission mode) indicated by the signaling of the base station (e.g., RRC signaling). Alternatively, when the sDCI mode or the mDCI mode is selected, the SFN transmission mode or the SDM transmission mode can be implicitly selected.

[0180] When the SFN transmission mode is used, a solution of sharing DM-RS ports or a solution of not sharing DM-RS ports may be considered.

[0181] The terminal can dynamically switch between STxMP (e.g., STxMP PUSCH transmission) and non-STxMP (e.g., non-STxMP PUSCH transmission). Non-STxMP can be interpreted as an operation supported by the technical specification. STxMP can be divided into STxMP SDM and STxMP SFN. STxMP SDM can be STxMP based on the SDM transmission scheme. STxMP SFN can be STxMP based on the SFN transmission scheme.

[0182] When the terminal operates under STxMP SDM, the maximum number of layers that can be scheduled, maxLayer, or the maximum number of ranks that can be scheduled, maxRank, can have different values for each Tx panel. The base station can notify the terminal of a pair of (maxLayer, maxRank) for each Tx panel through signaling (e.g., RRC signaling). The terminal can identify the pair of (maxLayer, maxRank) for each Tx panel indicated by the signaling (e.g., RRC signaling) of the base station. The combination of (maxLayer, maxRank) for each Tx panel may be restricted in the technical specifications. Alternatively, the combination of (maxLayer, maxRank) for each Tx panel may be restricted by the scheduler.

[0183] If the terminal is capable of performing transmission of up to four layers, the base station may indicate maxLayer=4 to the terminal. For maxLayer1 and maxLayer2 indicated to the terminal respectively, certain combinations may be restricted. The reason may be that maxLayer1=4 associated with Tx panel 1 and maxLayer2=4 associated with Tx panel 2 may be indicated to the terminal. According to the technical specification, the relationship (maxLayer1+maxLayer2≤maxLayer) may be maintained. Alternatively, according to the technical specification, the relationship (maxLayer1≤maxLayer) and the relationship (maxLayer2≤maxLayer) may be maintained. In this case, the scheduler may perform scheduling to satisfy the relationship (maxLayer1+maxLayer2≤maxLayer).

[0184] When the terminal operates under STxMP SFN, the value of maxLayer or maxRank for non-STxMP can be reused as the value of maxLayer or maxRank for STxMP SFN. Alternatively, the maxLayer or maxRank for STxMP SFN can have a different value from the maxLayer or maxRank for non-STxMP. To support the above operations, the base station can indicate the maxLayer or maxRank value for STxMP SFN to the terminal through signaling (e.g., RRC signaling). The terminal can identify the value of maxLayer or maxRank for STxMP SFN through signaling from the base station. The value of maxLayer supported in STxMP SFN shall not be greater than the maxLayer supported in non-STxMP.

[0185] 3. Application of transform precoding in STxMP PUSCH transmission

[0186] The terminal can transmit PUSCH scheduled by the fallback DCI format. The terminal can map one codeword to one DM-RS port. In the FR2 band, when the terminal is in the RRC connected state, it can be assumed that PUSCH is not scheduled by the fallback DCI format in the UL BWP, where the PUCCH resources do not have a spatial relationship or UL / joint TCI configured for PUCCH. Exceptionally, when enableDefaultBeamPL-ForPUSCH0-0 is enabled, PUSCH can be scheduled in the UL BWP.

[0187] The base station may indicate a dedicated PUCCH resource to the terminal through signaling (e.g., RRC signaling). The same spatial relationship as the dedicated PUCCH resource with the lowest ID among the dedicated PUCCH resources indicated to the terminal through signaling (e.g., RRC signaling) may be applied to PUSCH transmission. The above operation may be applied at least to the serving cell to which the PUCCH can be transmitted. When carrier aggregation (CA) is configured in the terminal, the same spatial relationship (e.g., the same Tx beam) as the dedicated PUCCH resource with the lowest ID may be applied to PUSCH transmission in another serving cell.

[0188] When the default beam is allowed (for example, when enableDefaultBeamPL-ForPUSCH0-0 is enabled), UL BWP 1, which does not have PUCCH configured, and UL BWP 2, which does have PUCCH configured, can be considered. In UL BWP 2, PUCCH can be configured, but spatial relationships cannot be configured for all PUCCH resources. The default beam can be used to estimate path loss to determine transmit power and / or derive the Tx beam.

[0189] To transmit the PUSCH in UL BWP 1, the terminal may derive the Tx beam using the default beam. To transmit the PUSCH in UL BWP 2, the terminal may derive the Tx beam using the default beam.

[0190] The default beam can be derived using a reference signal (RS) that takes into account the TCI state (i.e., QCL type) of the CORESET with the lowest ID among the CORESETs configured in the DL BWP of the serving cell (e.g., the serving cell including UL BWP 1 or UL BWP 2). When the CORESET has two TCI states, the terminal can use the first of the two TCI states to derive the default beam.

[0191] The base station may send information indicating whether transform precoding is applied to the PUSCH allocated by the fallback DCI to the terminal through signaling (e.g., RRC signaling). The terminal may identify whether transform precoding is applied to the PUSCH based on the signaling (e.g., RRC signaling) from the base station. In this case, the parameters associated with the active UL BWP may not be applied. The waveform for the PUSCH allocated by the non-fallback DCI may be determined by applying the parameters associated with the active UL BWP. When the parameters associated with the active UL BWP are indicated to the terminal, the waveform may be changed according to the scheduling information of the PUSCH. Alternatively, the waveform of the PUSCH may be changed through the MAC CE.

[0192] For example, waveform 0 may be associated with an active UL BWP, but waveform 1 may be indicated to the terminal through specific scheduling information or MAC CE.

[0193] DFT-s-OFDM can be allocated as a single layer when transform precoding is enabled and the number of consecutively scheduled PRBs is a multiple of 2, 3, or 5. Fallback DCI can always schedule a single layer.

[0194] When signaling (e.g., RRC signaling) instructs the terminal to perform STxMP or repeat PUSCH transmission, two or more SRS resource sets may be indicated to the terminal. Therefore, it may be necessary to indicate detailed operations to the terminal. According to the proposed method, the base station can explicitly indicate the SRS resource set to the terminal through signaling (e.g., RRC signaling). Alternatively, the terminal can determine the SRS resource set based on other information. Once the SRS resource set is determined, the DM-RS port can be used to indicate the SRS port of the SRS resource that the terminal can use.

[0195] Method 3-1: When transmission of one layer is performed for each Tx panel (or SRS resource set), a transform precoder may be applied.

[0196] Method 3-2: In method 3-1, in order to transmit PUSCH corresponding to all Tx panels (or all SRS resource sets), transform precoding may or may not be applied.

[0197] The terminal can change the PUSCH waveform based on the scheduling information. In other words, the terminal can use the scheduling information to enable or disable precoding transformation. When the terminal operates in sDCI mode, it can perform operations according to the single scheduling information. Therefore, the terminal can use the same waveform in all Tx panels.

[0198] When the terminal operates in mDCI mode, it can receive different scheduling information for each Tx panel (or SRS resource set). When the radio channel state is different for each Tx panel, the terminal can decide whether to apply transform precoding to each Tx panel. Even when the terminal operates in sDCI mode, the terminal can decide whether to apply transform precoding to each Tx panel in specific scenarios.

[0199] For example, one layer of transmission may be performed in one Tx panel, and two layers of transmission may be performed in another Tx panel. In this case, the terminal may perform transform precoding in the Tx panel that performs the transmission of one layer.

[0200] For another example, the timing advance (TA) for one Tx panel may be different from the TA for another Tx panel, and the difference between the path loss for one Tx panel and the path loss for another Tx panel may be large. In this case, even if one layer of transmission is performed in each TX panel, it may be preferable to perform transform precoding in one TX panel.

[0201] Method 3-3: In method 3-1, transform precoding may be applied to the transmission of PUSCH corresponding to one Tx panel (or SRS resource set), but transform precoding may not be applied to the transmission of PUSCH corresponding to another Tx panel (or SRS resource set).

[0202] In various exemplary embodiments of STxMP, application of transform precoding may be considered.

[0203] The terminal can be operated on Figure 3 As shown in STxMP SFN Mode 1, the terminal can perform transmissions for different DM-RS ports across the Tx panel. The terminal can use two DM-RS ports (or two layers) to send PUSCH. Since each Tx panel can have one DM-RS port, transform precoding can be applied to all or part of the Tx panels.

[0204] The terminal can be operated on Figure 4 As shown in STxMP SFN Mode 2, DM-RS ports can be shared between Tx panels. Therefore, one DM-RS port can be applied, and transform precoding can be interpreted as applied to all Tx panels.

[0205] The terminal can be operated on Figure 5 The STxMP SDM mode 1 is shown. STxMP SDM mode 1 can be applied to sDCI mode or mDCI mode. When a DM-RS port is applied to a Tx panel, transform precoding can be applied to the Tx panel.

[0206] The terminal can be operated on Figure 6 The STxMP SDM mode 2 is shown. STxMP SDM mode 2 can be applied to sDCI mode or mDCI mode. When a DM-RS port is applied to a Tx panel, transform precoding can be applied to the Tx panel.

[0207] When a terminal performs repeated PUSCH transmissions, it can schedule a different number of layers for each Tx panel or SRS resource set. Transform precoding can be applied to a Tx panel to which one layer is assigned. Based on scheduling information, the terminal can apply or not apply transform precoding even if one layer is assigned to a Tx panel.

[0208] 4. STxMP PUSCH transmission method considering dynamic waveform switching (DWS)

[0209] DFT precoding for dynamically allocated PUSCHs may or may not be dynamically applied. A terminal may transmit PUSCHs in an active UL BWP using various waveforms. PUSCH waveforms can be classified as the same as those for Msg3 PUSCH and waveforms associated with the UL BWP. These waveforms may include DFT-s-OFDM with DFT precoding or CP-OFDM without DFT precoding.

[0210] When the UL-DCI received at the terminal has DCI format 0_0 or is received in a cell-specific search space or a common search space (CSS), the waveform of the PUSCH scheduled by the UL-DCI may be the same as the waveform of the Msg3 PUSCH. When the UL-DCI received at the terminal has DCI format 0_1, when the UL-DCI received at the terminal has DCI format 0_2, or when the UL-DCI is received in a UE-specific search space (USS), the waveform of the PUSCH scheduled by the UL-DCI may be the same as the waveform derived from the configuration of the UL BWP.

[0211] When a terminal is located at the edge of a base station's coverage, the link budget for PUSCH transmission using DFT-s-OFDM can be greater than the link budget for PUSCH transmission using CP-OFDM. A terminal located at the center of a base station's coverage can move to the edge of the base station's coverage based on its mobility. Even when a terminal moves from the center of coverage to the edge of coverage, it is preferable that the terminal be able to dynamically change the PUSCH waveform to ensure reliable communication for the terminal without having to perform a separate procedure.

[0212] To dynamically change the waveform, the terminal can receive scheduling information to change the UL BWP. During the process of changing (or re-indicating) the UL BWP, the DFT precoder may or may not be applied, and radio frequency (RF) re-operation and other operations may be performed again. Therefore, unnecessary operations may need to be omitted.

[0213] The UL DCI may include an information field that dynamically indicates a waveform (e.g., a DWS field or a transform precoding indicator (TPI) field). When the DWS field has a first value, the terminal may apply a DFT precoder. When the DWS field has a second value, the terminal may not apply a DFT precoder.

[0214] The amount and / or type of information scheduled for each waveform may be different. To support this, known bits may be added to the information field included in the UL DCI so that the length of the information field is independent of the waveform. Depending on the waveform, the length of each information field may be longer. When a shorter waveform is used, the scheduling information may be interpreted based on a portion of the information field (e.g., the least significant bit (LSB) or the most significant bit (MSB)).

[0215] Considering repeated PUSCH transmissions, the waveform applied by the terminal for each Tx panel, SRS resource set, or PUSCH transmission may be different. This may be because the TRP expected to be received may be different for each PUSCH transmission. Since the link budget between the terminal and the TRP may be different, it is preferable to indicate DWS information for each link (e.g., each TRP).

[0216] Taking into account STxMP PUSCH transmission, the waveform applied to each Tx panel of the terminal may be different. Alternatively, for each TRP (or Rx panel of the TRP) that is the transmission target of the terminal, the applied waveform may be different. Therefore, it may be preferable to indicate the DWS field for each link. The following method can be used not only for UL-DCI scheduling STxMP PUSCH transmission, but also for other scenarios including two UL-TCIs, two TPMIs or two SRS resources (e.g., identifiers of SRS resources).

[0217] According to the proposed method, the size of the DWS field included in the UL-DCI can be 1 bit, and the DWS field can be commonly applied to all links. In this case, the waveform can be different in each Tx panel.

[0218] Method 4-1: The size of the DWS field included in the UL-DCI may be 1 bit, and the terminal may derive a waveform by commonly applying the DWS field to all PUSCHs.

[0219] When the terminal performs STxMP SDM PUSCH transmission, the terminal may perform one-layer transmission in one Tx panel. The terminal may determine the waveform for the Tx panel based on the value of the DWS field. When performing two or more layers of transmission in another Tx panel, the DWS field may not be applied to the other Tx panel.

[0220] When a terminal performs STxMP SDM PUSCH transmission or STxMP SFN PUSCH transmission, the terminal may perform layer transmission in all Tx panels. The terminal may determine the waveform for the Tx panel based on the value of the DWS field. The waveform may be the same in all Tx panels.

[0221] When DFT precoding is performed based on the value of the DWS field, the terminal may assume that one layer is allocated.

[0222] When the terminal performs STxMP SDM PUSCH transmission or STxMP SFN PUSCH transmission, two or more SRS resource sets (e.g., a first SRS resource set and a second SRS resource set) may be indicated or configured to the terminal. The DWS field of the UL-DCI may be indicated or configured as 1 bit, and the DWS field may be interpreted as indicating DFT precoding for one SRS resource set.

[0223] The method for selecting a certain SRS resource set from two or more SRS resource sets or the method for selecting a certain SRS resource set from two or more SRS resource sets may be defined in the technical specifications. Alternatively, the method for selecting a certain SRS resource set from two or more SRS resource sets or the method for selecting a certain SRS resource set from two or more SRS resource sets may be indicated to the terminal via higher layer signaling. The following method can be applied to the case of two SRS resource sets, but the following method can be easily extended and applied to three or more SRS resource sets.

[0224] Method 4-2: The DWS field may be interpreted as whether DFT precoding is performed on the first SRS resource set, but may not be used as information for the second SRS resource set.

[0225] Method 4-3: The DWS field may be interpreted as whether DFT precoding is performed on the second SRS resource set, but may not be used as information for the first SRS resource set.

[0226] Method 4-4: The SRS resource set to which the DWS field is applied may be indicated or configured through high-layer signaling, a first SRS resource set or a second SRS resource set may be selected, and the DWS field may be applied to the selected SRS resource set.

[0227] According to the proposed method, the size of the DWS field included in the UL-DCI may be 2 bits, and a different waveform may be used in each Tx panel.

[0228] Method 4-5: The size of the DWS field included in the UL-DCI may be 2 bits, and the terminal may derive a waveform for each PUSCH by applying the DWS field to each PUSCH.

[0229] Method 4-6: The DWS field size included in the UL-DCI may be 2 bits, and the 2 bits may be consecutive bits or non-consecutive bits. Another information field may be arranged between the two non-consecutive bits.

[0230] The DWS field included in the UL-DCI may be interpreted as a bitmap. The MSB of the DWS field may correspond to one Tx panel. The LSB of the DWS field may correspond to another Tx panel.

[0231] The DWS field included in the UL-DCI can be interpreted as a bitmap. The MSB of the DWS field can correspond to one TRP (or the Rx panel of the TRP, the CORESET pool index associated with the search space set / CORESET in which the UL-DCI is detected). The LSB of the DWS field can correspond to another TRP (or the Rx panel of the TRP, the CORESET pool index associated with the search space set / CORESET in which the UL-DCI is detected).

[0232] In the sDCI-based mTRP scenario, the terminal can repeatedly send PUSCH. Assuming that PUSCH is received at each TRP, the TPMI, SRS resources (e.g., SRI) and / or UL-TCI applicable to the link with the TRP can be separately indicated to the terminal. One TB can be allocated, and the terminal can send this one TB on PUSCH. In this case, one TB can be received at two TRPs. Therefore, even when two TPMI / UL-TCI / SRI are indicated to the terminal, transmission of the same number of layers can be performed. Even in this case, method 4-1, method 4-5 and / or method 4-6 can be applied.

[0233] It is possible to indicate that one layer of transmission is performed for each TRP in a TDM manner. In this case, the terminal may or may not apply DFT precoding to the link. To support the above operations, one value of the DWS field may correspond to all TRPs, and the terminal may or may not apply DFT precoding to all PUSCH transmissions.

[0234] It may be indicated that one layer of transmission is performed for each TRP in a TDM manner. In this case, the terminal may or may not apply DFT precoding to each link. To support the above operations, the size of the DWS field may be n bits. n may be an integer of 2 or greater. The MSB in the n bits may correspond to one TRP (or the Rx panel of a TRP, the CORESET pool index). The LSB in the n bits may correspond to another TRP (or the Rx panel of a TRP, the CORESET pool index).

[0235] 5.STxMP PUCCH transmission method

[0236] The terminal can use PUCCH (or PUSCH) to transmit UCI. When the PUCCH symbol overlaps with the PUSCH symbol, PUSCH can be used instead of PUCCH to transmit UCI. The PUCCH symbol may refer to a symbol in which PUCCH transmission is performed. The PUSCH symbol may refer to a symbol in which PUSCH transmission is performed. When the priority index of the PUCCH can be compared with the priority index of the PUSCH, inter-band CA can be activated, and PUCCH transmission and PUSCH transmission can be performed simultaneously in different frequency bands. If the above conditions are not met, the terminal can discard the PUCCH transmission and perform PUSCH transmission.

[0237] A terminal can use one DM-RS port to transmit a PUCCH. The Tx beam referenced by the PUCCH DM-RS port can be a default beam. Alternatively, the Tx beam referenced by the PUCCH DM-RS port can be explicitly indicated by the TCI state or spatial relationship information.

[0238] When a terminal has two or more Tx panels, it can use one DM-RS port to transmit the PUCCH. In this case, operations in accordance with the technical specifications can be performed. The base station can instruct the terminal to support two or more DM-RS ports. In this case, the terminal can use two or more Tx panels instead of two or more DM-RS ports in one Tx panel to perform transmission.

[0239] DM-RS ports can have orthogonal radio resources. When the same DM-RS port can be used, the radio channel estimated by the base station may mean two or more links. In this case, the operation of the terminal may be inaccurate.

[0240] Method 5-1: Two or more PUCCH DM-RS ports may be indicated to the terminal.

[0241] The terminal can support as many DM-RS ports as the number of Tx panels (or the number of antenna groups (Ng)). When two or more DM-RS ports are used, cyclic shifts, orthogonal cover codes (OCCs), and / or base sequences can be additionally allocated. The PUCCH format can be taken into account to determine the resources of the DM-RS ports.

[0242] Method 5-2: An additional offset of the cyclic shift for the additional PUCCH DM-RS port may be indicated to the terminal through signaling (eg, RRC signaling).

[0243] When PUCCH format 0 is used, according to method 5-2, one cyclic shift may be indicated by information indicated by scheduling information and / or signaling (e.g., RRC signaling) for the terminal, and this one cyclic shift may be used to derive the sequence of PUCCH DM-RS port 0, and (one cyclic shift + additional offset) may be used to derive the sequence of PUCCH DM-RS port 1. In this case, the base station may be aware of the reduction in multiplexing capacity of PUCCH format 0 and may reflect this multiplexing capacity in scheduling multiple users.

[0244] The value of the additional offset can be +1 or -1. When the terminal sends a 2-bit HARQ-ACK, the terminal can use 4 cyclic shifts. To maximize detection performance at the base station, the difference between adjacent cyclic shifts can be 3. When the terminal sends a 1-bit HARQ-ACK, the difference between adjacent cyclic shifts can be 6. Therefore, it is preferable not to set the additional offset for the cyclic shift to 3 or 6. It is preferable that the terminal use adjacent cyclic shifts. Adjacent cyclic shifts can be represented by ±1.

[0245] Method 5-3: The additional offset of the OCC of the additional PUCCH DM-RS port may be indicated to the terminal through signaling (eg, RRC signaling).

[0246] When PUCCH format 1 or PUCCH format 4 is used, according to method 5-3, one index can be indicated by information indicated by scheduling information and / or signaling (e.g., RRC signaling) for the terminal, and the one index can be used to derive the OCC applied to PUCCH DM-RS port 0, and (one index + additional offset) can be used to derive the OCC applied to PUCCH DM-RS port 1.

[0247] To meet frequency domain regulations in communication systems supporting unlicensed bands, PRBs can be allocated so that PUCCH resources have interleaved mapping. PRBs can be spread so that PUCCH resources have interleaved mapping. In this case, due to the reduced multiplexing capacity, additional spreading sequences can be applied in the scheduling of multiple users. According to method 5-3, an additional OCC can be used and applied to PUCCH DM-RS port 1. The additional OCC can be an OCC with an additional offset applied.

[0248] When the amount of UCI is large, in PUCCH format 2 and / or PUCCH format 3, the terminal may compare the code rate indicated by signaling (e.g., RRC signaling) (hereinafter referred to as the 'reference code rate') with the effective code rate of the UCI. The terminal may determine whether the effective code rate is higher or lower than the reference code rate. When the effective code rate is higher than the reference code rate, the terminal may not select the PUCCH associated with the effective code rate, but may select another PUCCH including more PRBs than the PUCCH associated with the effective code rate. For example, considering the PUCCH carrying the CSI report, two PUCCH resources may be indicated to the terminal, and the terminal may select one PUCCH resource from the two PUCCH resources.

[0249] When the effective code rate is lower than the reference code rate, the terminal may perform an operation to reduce the number of PRBs. Alternatively, the terminal may reduce the number of UCIs. For example, the terminal may discard a CSI report with a lower priority. The CSI report may be divided into CSI Part 1 and CSI Part 2. In this case, the terminal may discard CSI Part 2 and send CSI Part 1. Alternatively, the terminal may send CSI Part 1. In other words, the terminal may select a CSI report with a higher priority and send the selected CSI report. Alternatively, the terminal may send all of CSI Part 1 and a portion of CSI Part 2. In this case, the portion of CSI Part 2 sent by the terminal may be CSI Part 2 belonging to a higher priority CSI report.

[0250] When the PUCCH resource has M RB RB, UCI in N symb OFDM symbols, and the maximum code rate of UCI is r, the terminal can calculate It can indicate the number of REs to which UCI is mapped within an RB. Can be a constant. m In binary phase shift keying (BPSK) of π / 2, it can be 1. Q m In Quadrature Phase Shift Keying (QPSK) it can be 2. mWhen a PUCCH resource supports one DM-RS port, the above operation can be applied.

[0251] When two or more DM-RS ports are supported, the terminal can perform PUSCH transmission using all Tx panels based on STxMP. In this case, the base station can instruct the terminal to perform STxMP SFN PUCCH transmission or STxMP SDMPUCCH transmission. Alternatively, STxMP SFN PUCCH transmission or STxMP SDM PUCCH transmission can be determined according to the technical specifications. Alternatively, the technical specifications may specify only one of STxMP SFN PUCCH transmission or STxMP SDM PUCCH transmission. STxMP SFN PUCCH transmission may refer to STxMP PUCCH transmission based on SFN mode. STxMP SDM PUCCH transmission may refer to STxMP PUCCH transmission based on SDM mode.

[0252] The coded UCI in STxMP SFN PUCCH transmissions can be mapped commonly to all DM-RS ports. The coded UCI in STxMP SFN PUCCH transmissions can be mapped based on codeword-to-layer mapping. STxMP can be a process related to the transmission of coded UCI, and the transmission related to DM-RS ports can be performed differently from STxMP. For example, coded UCI can be sent based on STxMP SFN PUCCH transmissions, but two or more DM-RS ports can be indicated, and the two or more DM-RS ports can use orthogonal resources.

[0253] When performing STxMP SDM PUCCH transmission, different methods may be applied according to the PUCCH format.

[0254] Method 5-4: When using PUCCH format 0 and / or PUCCH format 1, the same sequence can be mapped and transmitted in all layers. It may be preferable to change the equation applied to PUCCH format 2, PUCCH format 3 and / or PUCCH format 4, where 3 or more bits of UCI can be transmitted.

[0255] Method 5-5: When using LPUCCH resources indicated with L DM-RS ports, the amount of UCI that can be sent on the PUCCH can be bits.

[0256] When L≤2, the effective coding rate of the UCI can be reduced to 1 / L. The terminal can generate coded UCI by performing a coding process on the UCI, and can perform a modulation process on the coded UCI. Then, the terminal can perform a codeword-to-layer mapping process.

[0257] Method 5-6: One or two codewords may be generated for UCI based on the type of UCI (e.g., HARQ-ACK, CSI, etc.). The codeword-to-layer mapping process for codewords may be performed in the order considered in the technical specification. For example, the codeword-to-layer mapping process for HARQ-ACK may be performed first, followed by the codeword-to-layer mapping process for CSI.

[0258] UCI with different UCI types may belong to different codewords (or different encoding processes). If the amount of UCI is large, a segmentation process may be performed on the UCI. If the UCI type (e.g., UCI with a UCI type) is divided into two codewords, the terminal may perform a layer-to-port mapping process on the first codeword and a codeword-to-layer mapping process on the second codeword.

[0259] According to methods 5-6, a method of mapping codewords to UCI types (eg, a method of mapping codewords to layers) may be as shown in Table 6 below. Table 6 shows a method of mapping between codewords and layers when the SDM mode is adopted. (n) (i) may represent the i-th coded bit (eg, modulation symbol, d(i)) mapped to DM-RS port n. The terminal may apply the same process to other UCI types according to the order considered in the technical specification.

[0260] [Table 6]

[0261]

[0262] When performing STxMP SFN PUCCH transmission, the terminal may apply the same method (eg, the same process) regardless of the PUCCH format. For example, for PUCCH format 0 and / or PUCCH format 1, the same sequence may be mapped to all layers.

[0263] Methods 5-7: In the case of PUCCH format 0 and / or PUCCH format 1, the same sequence can be mapped and transmitted in all layers. It may be preferable to reuse the equations applied to PUCCH format 2, PUCCH format 3, and / or PUCCH format 4, where 3 or more bits of UCI can be transmitted.

[0264] According to methods 5-7, the method of mapping between codewords and UCI types (for example, the method of mapping codewords to layers) can be as shown in Table 7 below. Table 7 shows the method of mapping between codewords and layers when the SFN mode is adopted. (n) (i) may represent the i-th coded bit (eg, modulation symbol, d(i)) mapped to DM-RS port n. The terminal may apply the same process to other UCI types according to the order considered in the technical specification.

[0265] [Table 7]

[0266]

[0267] Although the terminal supports two or more PUCCH DM-RS ports, one DM-RS port (e.g., each PUCCH DM-RS port) can correspond to each Tx panel. In this case, the transform precoder can be applied to each Tx panel. The transform precoder can be applied to PUCCH format 3 or PUCCH format 4.

[0268] Method 5-8: Even when the terminal uses two or more DM-RS ports, the terminal may apply a transform precoder to each DM-RS port.

[0269] In STxMP SDM PUCCH transmissions, the coded bits can be distributed across layers. Therefore, the terminal can apply a transform precoder to each DM-RS port (or Tx panel). In STxMP SFN PUCCH transmissions, the coded bits can be applied equally across layers. Therefore, the terminal can apply a transform precoder to different DM-RS ports.

[0270] In STxMP SDM PUCCH transmission or STxMP SFN PUCCH transmission, codebook-based transmission or non-codebook-based transmission can be performed. When each PUCCH DM-RS port (or Tx panel) can operate independently, the TPMI can refer to a diagonal matrix. For example, the TPMI can be

[0271] The TPMI or SRI applied to the PUCCH DM-RS can be derived from the information configuring the PUCCH resources. The TPMI or SRI applied to the PUCCH DM-RS may not be explicitly derived from scheduling information (eg, scheduling DCI).

[0272] Method 5-9: The TPMI (or Tx beam) applied to the PUCCH DM-RS may be derived from the PUCCH resource, and the TPMI (or Tx beam) applied to the PUCCH DM-RS may not be explicitly indicated by scheduling information.

[0273] When there are two or more spatial relationship information (or UL / joint TCI) referenced by a PUCCH resource, the base station can instruct the terminal to change / release certain UL / joint TCIs. According to the technical specification, when repeated PUCCH transmission is performed in the time domain, one or more UL / joint TCIs applied sequentially can be indicated to the terminal. When STxMP PUCCH transmission is supported, the UL / joint TCI can be updated using the same signaling. The terminal can interpret the UL / joint TCI sent by the base station as the UL / joint TCI applied to the simultaneous transmission of the PUCCH.

[0274] 6.STxMP UL coherence window derivation method

[0275] The terminal can use retransmission to extend UL coverage. The retransmission method in STxMP PUSCH transmission or STxMP PUCCH transmission will be described below. The UL signal / channel may include at least PUSCH or PUCCH. In addition, the UL signal / channel may refer to SRS.

[0276] The base station can select a Tx panel of the terminal and instruct the terminal to repeatedly transmit the UL signal / channel using the selected Tx panel. The base station can select a radio link with higher quality. In this case, the effective code rate can be reduced.

[0277] Method 6-1: In the central area of the UL coverage, the terminal may transmit a UL signal / channel based on the STxMP scheme. The terminal may assume that the STxMP UL signal / channel is not repeatedly transmitted. The STxMP UL signal / channel may refer to a UL signal / channel based on the STxMP scheme.

[0278] The quality of the radio link may vary greatly due to obstruction. If the power (e.g., transmit power) of each Tx panel is controllable, the terminal can use two or more Tx panels at the same time. The base station can instruct the terminal to repeat the transmission of the UL signal / channel. If the transmit power of a terminal located in an edge area of the UL coverage range is increased, the interference caused by the transmission of the terminal may significantly affect the adjacent base stations. Therefore, it may be preferable that the terminal reduce the effective code rate while maintaining an appropriate transmit power.

[0279] Method 6-2: The terminal may receive scheduling information for retransmitting the STxMP UL signal / channel.

[0280] The base station may send signaling (e.g., RRC signaling) to the terminal indicating additional DM-RS bundling when performing retransmission of the UL signal / channel. The terminal may recognize that the DM-RS bundling is indicated by the signaling (e.g., RRC signaling) of the base station. When the DM-RS of the UL signal / channel is received in multiple time slots, the base station may perform a joint channel estimation operation for the DM-RS. In this case, the gain of the channel estimation operation may be improved. In order to support the above operations, the terminal may maintain consistency (e.g., power consistency and / or phase continuity) during the time slots in which the DM-RS is sent and received.

[0281] The time during which the terminal maintains consistency can be referred to as the nominal time domain window (TDW) and / or the actual TDW. An event may occur during which consistency is not maintained within the nominal TDW. After such an event, consistency may not be maintained. The time before the event may be referred to as the actual TDW. Depending on the UE capabilities, the terminal may restart the actual TDW after the event occurs. In this case, the terminal may still maintain consistency even after the event occurs.

[0282] Events can be categorized as semi-static events and dynamic events. Semi-static events can refer to events where consistency cannot be maintained before the end of the nominal TDW due to semi-statically reflected information (e.g., frequency hopping, TDD slot mode, etc.). Dynamic events can refer to events where consistency cannot be maintained before the end of the nominal TDW due to dynamically received information (e.g., group-common DCI, scheduling DCI).

[0283] The terminal may assume that the actual TDW is generated due to a static event (e.g., frequency hopping, change of SRS resource set, change of spatial relationship information, change of UL / joint TCI, and / or change of power control parameters) rather than a dynamic event, and consistency is maintained by the actual TDW. The following events may be considered as events in which consistency is not maintained. Depending on the UE capabilities, the actual TDW may not be generated after the event occurs. Alternatively, depending on the UE capabilities, the actual TDW may be generated after the event occurs.

[0284] The reception operation in the DL symbol indicated by signaling (e.g., RRC signaling) between UL symbols can be regarded as an event. The above situation can be regarded as an event when a gap of more than 13 symbols (or 11 symbols in the case of extended cyclic prefix (CP)) occurs between two consecutive UL transmissions (e.g., PUSCH / PUCCH transmissions). The above situation can be regarded as an event if another UL transmission is scheduled despite the occurrence of a gap of no more than 13 symbols or 11 symbols between two consecutive UL transmissions. The above situation can be regarded as an event when PUSCH repetition type A is applied, when PUSCH repetition type B is applied, when a TB is mapped to multiple time slots (e.g., TB processing on multiple time slots), when PUSCH transmission is dropped / canceled due to UL priority / multiplexing procedures, when PUSCH transmission is dropped / canceled due to differences in time slot patterns, and / or when PUSCH transmission is dropped / canceled due to uplink cancellation indication (ULCI). When two SRS resource sets are configured for two consecutive UL transmissions according to PUSCH repetition type A / B, PUSCH transmission is performed based on codebook or non-codebook, and the association relationship of the SRS resource sets changes, the above situation can be considered an event. When the spatial relationship information (or UL / joint TCI) for two consecutive PUSCH repetitions changes, or when the power control parameters for two consecutive PUSCH repetitions change, the above situation can be considered an event. When the reception / application operation of the TA command or TA value for timing alignment is performed, the above situation can be considered an event. When frequency hopping is performed, the above situation can be considered an event.

[0285] The terminal may determine the number of Tx panels (eg, one Tx panel or two or more Tx panels) to be used for STxMP UL transmission based on the dynamic scheduling information. In this case, the terminal may apply an event to maintain consistency by considering the determined Tx panel.

[0286] In the mDCI-based mTRP scenario, two TRPs can instruct the terminal to send UL signals / channels (e.g., UL 1 and UL 2) using independent scheduling information. In the sDCI-based mTRP scenario, the terminal can perform UL signal / channel transmission (e.g., UL 1 and UL 2) based on scheduling information received from one TRP.

[0287] UL 1 and UL 2 can be allocated non-overlappingly in the time domain. UL 1 and UL 2 can be transmitted by the same Tx panel. Alternatively, UL 1 and UL 2 can be transmitted by different Tx panels. In this case, the terminal can perform UL transmission for either UL 1 or UL 2. Alternatively, the terminal can perform transmission for both UL 1 and UL 2.

[0288] Even if UL 1 and UL 2 do not overlap in the time domain, if an actual TDW for UL 1 or UL 2 is generated, the terminal may perform transmission in the Tx panel considering the actual TDW.

[0289] Retransmissions may be scheduled for UL 1, and transmissions may be scheduled for UL 2. The above situation may be considered in the following exemplary embodiments.

[0290] Figure 7 is a conceptual diagram of a first exemplary embodiment showing events occurring in STxMP transmission.

[0291] refer to Figure 7 , retransmission of UL 1 using two Tx panels (e.g., Tx panel 0 and Tx panel 1) can be scheduled in the terminal, and transmission of UL 2 using Tx panel 1 can be scheduled in the terminal.

[0292] When DM-RS bundling is indicated to the terminal, the terminal may generate a nominal TDW when performing retransmissions on UL 1. The nominal TDW may be divided into two or more actual TDWs according to events defined in the technical specifications.

[0293] In the proposed method, the terminal can maintain an actual TDW. When an event occurs in one Tx panel, the event can be applied to all Tx panels. In another proposed method, when an event occurs in one Tx panel, the event can be applied to some Tx panels.

[0294] Method 6-3: Events can be applied to all activated Tx panels together.

[0295] Figure 7 In an exemplary embodiment, a nominal TDW can be generated for UL 1 retransmissions, and UL 2 scheduling can be interpreted as an event. In this case, the actual TDW in Tx Panel 1 can be divided into two parts. The base station can sequentially receive UL 1 transmissions, UL 2 transmissions, and UL 1 transmissions, and can independently perform channel estimation operations for UL 1 transmissions, UL 2 transmissions, and UL 1 transmissions. When performing UL 1 retransmissions, the terminal does not need to maintain consistency.

[0296] The actual TDW may be generated by power control and scheduling of UL 2. In this case, the event may be applied to all Tx panels.

[0297] According to method 6-3, the implementation performance can be improved. If the actual TDW for each Tx panel can be obtained, the channel estimation performance of the base station can be further improved.

[0298] Method 6-4: Events can be applied to certain Tx panels.

[0299] Figure 7 In an exemplary embodiment, the scheduling of UL 2 in Tx Panel 0 can be interpreted as an event, but no event will occur in Tx Panel 1. The terminal may not be able to maintain the consistency of UL 1 transmission in Tx Panel 0, but the terminal can maintain the consistency of UL 1 transmission in Tx Panel 1. In other words, the terminal can manage the actual TDW for each Tx Panel. According to Method 6-4, the nominal TDW can be managed regardless of the Tx Panel, and the event that generates the actual TDW can be managed for each Tx Panel.

[0300] In order for the terminal to manage two or more actual TDWs, separate UE capabilities may be supported. Depending on the UE capabilities, the terminal may apply method 6-3 or method 6-4.

[0301] Method 6-5: Depending on the UE capabilities, the method of interpreting the event can be derived in different ways.

[0302] 7. Uplink Timing Alignment Method

[0303] In the mTRP scenario, the relative distances between the terminal and each TRP may be similar. Alternatively, in the mTRP scenario, the relative distances between the terminal and each TRP may be significantly different. In the mTRP scenario, it is possible to consider the case where the terminal is located in the center area of the communication coverage area, and / or the case where the absolute propagation delay is small because the communication coverage area is not large. The terminal may assume a DL timing and a UL timing. The timing may be the timing for performing an inverse fast Fourier transform (IFFT) and / or FFT. The boundaries of the OFDM symbols may be derived based on the timing.

[0304] Figure 8 is a conceptual diagram illustrating a first exemplary embodiment of a timing alignment method.

[0305] refer to Figure 8 , the base station and the terminal can interpret time slot n. The time slot boundaries of the base station can be different from the time slot boundaries of the terminal. Taking into account the propagation delay, the DL timing and UL timing can be derived. The difference between the DL timing and the UL timing is called the timing advance (TA).

[0306] In the mTRP scenario serving wide coverage, relatively large propagation delays may be considered, L1 / L2-based mobility functions may be supported, and inter-cell beam management may be supported. The relative propagation delay between TRPs may be large. In this case, the propagation delay may be longer than the CP of the OFDM symbol. In this case, the terminal may assume one or more DL timings and one or more UL timings. The above assumptions may mean that the number of FFT / IFFT engines increases and / or their execution time becomes faster. Therefore, the above operations (e.g., assumptions) may be operations based on UE capabilities.

[0307] Method 7-1: The terminal may assume one or more DL timings and one or more UL timings according to UE capabilities.

[0308] Figure 9 is a conceptual diagram illustrating a second exemplary embodiment of a timing alignment method.

[0309] refer to Figure 9 , the terminal may have two DL timings, and the terminal may have one TA. The DL reference time may represent the DL timing. The UL reference time may represent the UL timing. The terminal derives the DL timing from two or more TRPs. In other words, the terminal may determine the DL timing for two or more Tx panels of the terminal. The TA may be derived based on the following information: the difference between DL timing 1 (e.g., DL reference time 1) and UL timing 1 (e.g., UL reference time 1) or the difference between DL timing 2 (e.g., DL reference time 2) and UL timing 2 (e.g., UL reference time 2). When two or more SRS resource sets are indicated to the terminal, the terminal may apply one TA to operate in STxMP mode, TDM mode, or sTRP mode. The STxMP mode or TDM mode may be an mTRP mode. In mTRP mode, the terminal may communicate with multiple TRPs. In sTRP mode, the terminal may communicate with one TRP.

[0310] Since the delay time between each TRP and the terminal may be different, different TAs may be preferably applied to the corresponding TRPs. Therefore, the terminal can manage two TAs. The base station can indicate two TA groups (TAGs) to the terminal. The terminal can identify the two TAGs indicated by the base station and perform closed-loop control using TA commands or TA values. In addition or alternatively, the terminal can perform autonomous adjustment. The two TAGs can be associated with different TRPs, respectively.

[0311] The derived DL timing may be interpreted as a DL subframe boundary or a DL slot boundary. Alternatively, the derived DL timing may be interpreted as a UL subframe boundary or a UL slot boundary.

[0312] Figure 10is a conceptual diagram illustrating a third exemplary embodiment of a timing alignment method.

[0313] refer to Figure 10 , the terminal may have one DL timing, and the terminal may have two TAs. The DL reference time may represent the DL timing. The UL reference time may represent the UL timing. In the mTRP scenario, the terminal may operate in mDCI mode. The delay for TxP and the delay for RxP may be asymmetric. The terminal may operate in sDCI mode, receive data from one TxP, and send data to two or more RxPs. The terminal may derive (e.g., determine) the DL timing from one TRP, and may derive (e.g., determine) UL timing 1 and UL timing 2 based on the DL timing. In other words, the terminal may derive TA 1 and TA 2. The base station may indicate two TAGs to the terminal. The terminal may recognize the two TAGs indicated by the base station and perform closed-loop control using a TA command (or TA value). In addition or alternatively, the terminal may perform autonomous adjustment.

[0314] Figure 11 is a conceptual diagram illustrating a fourth exemplary embodiment of a timing alignment method.

[0315] refer to Figure 11 The terminal may have two DL timings and two UL timings. The terminal may have two TAs. The DL reference time may represent the DL timing. The UL reference time may represent the UL timing. Figure 11 An exemplary embodiment of may be Figure 7 This embodiment is a general example embodiment of an exemplary embodiment of the present invention. TA 1 and TA 2 can be derived based on the difference between each DL timing and UL timing. TA 1 and TA 2 can be signaled to the terminal. The base station can indicate two TAGs to the terminal. The terminal can identify the two TAGs indicated by the base station and perform closed-loop control using TA commands. Additionally or alternatively, the terminal can perform autonomous adjustments.

[0316] In the mTRP scenario, the terminal may operate in the mDCI mode and manage the radio link between the TRP and the Tx panel of the terminal and / or the radio link between the TRP and the Rx panel of the terminal respectively.

[0317] The terminal may receive a contention-free random access (CFRA) indication from a TRP (or base station) to determine UL timing. The CFRA indication may refer to a PDCCH command. The terminal may receive a PDCCH command and send a physical random access channel (PRACH) preamble based on the PDCCH command. The PDCCH command may trigger the terminal to perform an RA process. The PDCCH command may use DCI format 1_0. The DCI format 1_0 for the PDCCH command may include an identifier of the DCI format, a frequency domain resource allocation (FDRA), a random access preamble index (RAPID), a UL / supplementary UL (SUL) indicator, an SS / PBCH index, a PRACH mask index, and / or reserved bits. In addition, the PDCCH command may further include a TAG ID. When a PDCCH command is received from TRP 0, the TAG indicated by the TAG ID included in the PDCCH command may be associated with the TA between TRP 0 and the terminal. Alternatively, when a PDCCH command is received from TRP 0, the TAG indicated by the TAG ID included in the PDCCH command may be associated with the TA between the terminal and TRP 1 (instead of TRP 0). The PDCCH command may include two or more TAG IDs. In this case, the two or more TAG IDs may include the TAG ID of TRP 0 and the TAG ID of TRP 1. The initial TA may be derived based on the PRACH preamble. The initial TA may be managed as UL Timing 2, separate from UL Timing 1, under open-loop control.

[0318] The terminal can use DL timing to derive the UL timing for transmitting the PRACH preamble. When one DL timing is applied to the terminal, the terminal can assume TA 2 = 0 and send the PRACH preamble. The terminal can derive the PRACH preamble index, PRACH mask, SSB index, additional physical cell identifier (PCI), etc. based on the PDCCH command. The additional PCI can be a PCI different from the PCI of the serving cell. For example, when a PDCCH command is received from TRP 0, the additional PCI included in the PDCCH command may correspond to TRP 1 instead of TRP 0. In this case, the terminal can send the PRACH preamble to TRP 1 indicated by the additional PCI included in the PDCCH command.

[0319] The DCI indicating the PDCCH command may include a separate field, and this separate field may indicate to the terminal whether the PCI included in the PDCCH command is an additional PCI. This separate field may be configured as 1 bit, and the first value of this separate field may indicate that the PCI included in the PDCCH command is an additional PCI, and the second value of this separate field may indicate that the PCI included in the PDCCH command is the PCI of the serving cell. Preferably, the terminal receives an indication or configuration of the serving cell's PCI and the additional PCI via RRC signaling.

[0320] The PCI may be derived based on the bit indicated by the DCI indicating the PDCCH command, and the random access opportunity resource that the terminal may select may be derived based on a combination of the derived PCI and the SSB block index.

[0321] The PRACH preamble may be transmitted based on the DL timing determined from the SSB received from TRP 1. For another example, when a PDCCH order is received from TRP 0, and the SSB index included in the PDCCH order corresponds to TRP 1 instead of a specific SSB of TRP 0, the terminal may transmit the PRACH preamble to TRP 1 based on the DL timing measured based on the specific SSB of TRP 1 indicated by the SSB index included in the PDCCH order.

[0322] The terminal may use the DL timing reflecting TA 1 (eg, the DL timing managed by TA 1). Alternatively, the terminal may use a new DL timing. The terminal may obtain TA 2 of TRP 2 (eg, actual TA 2) while tracking TA 1 of TRP 1.

[0323] Method 7-2: The terminal may assume TA2=0 based on the DL timing of the DL signal / channel received from the serving cell (or TRP 1).

[0324] The base station may receive a PRACH preamble from the terminal, determine an initial TA 2 based on the PRACH preamble, and send the initial TA 2 to the terminal. The initial TA 2 may represent the difference between the DL timing 1 of TRP 1 and the UL timing 2 of TRP 2. Therefore, the initial TA 2 may be different from the actual TA 2. In order to correct the difference between the initial TA 2 and the actual TA 2, a TA loop managed by the base station (e.g., a separate TAG for TRP 2) may be used. Alternatively, when the terminal is capable of performing two or more FFT / IFF operations according to UE capabilities, the terminal may measure the difference between DL timing 1 and DL timing 2, and may derive the actual TA 2 based on the measured difference and the initial TA 2. Even when the terminal does not support separate UE capabilities (e.g., UE capabilities supporting the performance of two or more FFT / IFFT operations), the terminal may utilize DL timing 2. In this case, the terminal may derive DL timing 2 by receiving the SSB without receiving data from TRP 2 (e.g., SIB, control information in CORESET, etc.).

[0325] When the sDCI mode is used in the mTRP scenario, method 7-2 can be applied. When the sDCI mode is used, the core set pool index may not be indicated to the terminal, and in this case, the terminal's operation can be the same as that using one core set pool index. In this case, the terminal can manage one DL reception timing. This DL reception timing can represent the DL timing.

[0326] When the mDCI mode is used in the mTRP scenario, method 7-2 can be applied. The base station can indicate the CORESET pool index to the terminal, and the terminal can identify the CORESET pool index indicated by the base station. In this case, the terminal can (only) manage the DL reception timing associated with the first CORESET pool index. Therefore, the terminal can apply the DL reception timing derived from the first CORESET pool index without separately managing the DL reception timing associated with the second CORESET pool index.

[0327] When the UE capability of supporting two or more FFT / IFFT operations is supported, DL Timing 1 and DL Timing 2 may already be managed. In this case, the terminal may regard the transmission reference of the PRACH preamble as DL Timing 2. Even if a separate UE capability (e.g., a UE capability supporting two or more FFT / IFFT operations) is not supported, the terminal may utilize DL Timing 2. In this case, the terminal may derive DL Timing 2 by receiving the SSB without receiving data from TRP 2 (e.g., SIB, control information in CORESET, etc.).

[0328] Method 7-3: The terminal may assume TA 2=0 using the DL timing (eg, DL timing 2) at which the SSB (and / or additional PCI) corresponding to the SSB index derived from the PDCCH command is received.

[0329] When the mDCI mode is used in the mTRP scenario, method 7-3 can be applied. The base station can indicate one or more CORESET pool indexes to the terminal, and the terminal can identify the one or more CORESET pool indexes indicated by the base station. In this case, the terminal can manage two or more DL reception timings. The CORESET pool index can correspond to the corresponding TRP. TRP 1 that sends the PDCCH command received by the terminal can be different from TRP 2 that receives the PRACH preamble sent by the terminal. Therefore, TA 2 used to transmit the PRACH preamble can be the DL reception timing of TRP 2. In other words, TRP 1 can send a PDCCH command including an SSB index (or PCI of TRP 2) to the terminal, which is information about a specific SSB of TRP 2. The terminal can receive the PDCCH command from TRP 1 and identify the information element included in the PDCCH command. When the SSB index included in the PDCCH order of TRP 1 corresponds to a specific SSB of TRP 2, or when the PCI included in the PDCCH order of TRP 1 corresponds to TRP 2, the terminal can send a PRACH preamble code to TRP 2 according to the DL timing measured based on the specific SSB of TRP 2.

[0330] When managing two TAs, the two TAs can be managed in different TAGs. The TA between the terminal and TRP 1 can be managed in TAG 1, while the TA between the terminal and TRP 2 can be managed in TAG 2. The TA used for transmitting UL signals / channels can be explicitly indicated to the terminal. Alternatively, the terminal can implicitly derive the TA used for transmitting UL signals / channels. Generally speaking, the terminal can derive (e.g., determine) DL Timing 1, DL Timing 2, UL Timing 1, and / or UL Timing 2.

[0331] Method 7-4: The DCI scheduling the UL signal / channel may include a TAG ID or TAG information.

[0332] The DCI may include a separate field indicating the TAG ID. Alternatively, the TAG ID may be derived based on an existing field included in the DCI or a combination of existing fields thereof. Alternatively, the TAG ID may be another identifier that identifies the TAG.

[0333] When the number of tags is limited to two, the tag ID can be represented by 1 bit. For example, 1 bit (e.g., tag ID) can be used to indicate one of the two tags. If the tag ID has a value of 2 or 3, 1 bit can be used in the DCI to represent one tag. To support the above operations, the mapping relationship between the tag ID and the tag can be indicated or configured to the terminal through RRC signaling.

[0334] The TAG ID may be included in a MAC CE including a TA command or a TA value. When sending a PRACH in the RA process, the base station may send a random access response (RAR) including a TA command (or TA value) and a TAG ID to the terminal. Alternatively, the base station may send a MAC CE including a TA command and a TAG ID to the terminal, or send a MAC CE including a TA value and a TAG ID.

[0335] The RAR or MAC CE may include information capable of indicating a TAG. One bit may be additionally included in the RAR or MAC CE to indicate one of the two TAGs.

[0336] When using the mTRP mode, a contention-free random access (CFRA) indication or a PDCCH command can be sent to the terminal from one TRP (e.g., TRP 0). In this case, the terminal can send a PRACH preamble to another TRP (e.g., TRP 1). In other words, the terminal can send a PRACH preamble to TRP 1 based on the CFRA indication or PDCCH command received from TRP 0. The CFRA configuration information or PDCCH command can be received at panel 0 of the terminal, and the PRACH preamble can be sent at panel 1 of the terminal.

[0337] The terminal may receive information (eg, RAR, MAC CE) including a TA command (TAC) (or TA value) and a TAG ID from TRP 0 or TRP 1 .

[0338] Method 7-5: The terminal may receive information including a TAC (or a TA value) and a TAGID (or a TAG identifier) from TRP 0 (eg, a TRP that triggers CFRA).

[0339] Method 7-6: The terminal may receive information including a TAC (or TA value) and a TAG ID (or TAG identifier) from TRP 1 (eg, a TRP that receives a PRACH preamble).

[0340] When method 7-5 is applied, the terminal can receive information (e.g., TAC and TAG) on a UE-specific PDSCH. In other words, the terminal can obtain information (e.g., TAC and TAG) from a PDSCH including an RAR. When method 7-6 is applied, the terminal can obtain information (e.g., TAC and TAG) from a PDSCH including an RAR. Taking into account the beam correspondence, the terminal can derive a Tx beam corresponding to an Rx beam in which a DL signal / channel providing qcl-typeD is received. In this case, the terminal can derive information about the beam, but may not be able to identify information about the TA. Therefore, the terminal may need information about the TRP, information corresponding to the TRP, a panel and / or information corresponding to the panel. In this case, it may be preferred that the base station indicates an identifier of the DL signal / channel and / or an identifier of the UL signal / channel and a TAG ID to the terminal.

[0341] The base station may indicate the TCI state (or TCI state index) to the terminal through signaling (e.g., RRC signaling). In this case, the TCI state may include one or more TCIs. One TCI may include an identifier of a DL signal / channel or an identifier of a UL signal / channel providing qcl-type1 and / or qcl-type2. According to the proposed method, the terminal may derive a TAG ID (e.g., a TAG ID of TRP 0 and / or a TAG ID of TRP 1) and a DL signal / channel (e.g., an identifier of a DL signal / channel) or a UL signal / channel (e.g., an identifier of a UL signal / channel) from information indicating spatial relationship information or TCI (e.g., UL TCI). In addition, the terminal may also derive the reception timing (e.g., DL reception timing).

[0342] Method 7-7: When DL TCI is indicated, it may be assumed that the reception timing of a DL signal / channel providing qcl-typeA or qcl-typeD is the same as the reception timing of a DL signal / channel 1 to which DL TCI is applied.

[0343] Method 7-8: When UL / joint TCI (or SRI) is indicated, not only information for generating a Tx beam can be derived from the DL signal / channel (e.g., an identifier of the DL signal / channel) or the UL signal / channel (e.g., an identifier of the UL signal / channel), but also the TA or the group to which the TA belongs can be derived.

[0344] When the UL signal / channel is referenced by UL / joint TCI, for the PUSCH to which the UL / joint TCI is applied, the transmission timing (e.g., UL timing) of the PUSCH and the UL signal / channel can be assumed to be the same. When the DL signal / channel is referenced by UL / joint TCI, for the PUSCH to which the UL / joint TCI is applied, the TRP for transmitting the DL signal / channel and the TRP for receiving the PUSCH can be expected to be the same. In this case, the terminal can use the DL signal / channel to derive the Tx beam and / or transmission timing of the PUSCH.

[0345] Although the above exemplary embodiments have been described as being applied to PUSCH transmission, the above exemplary embodiments may also be applied to transmission of PUCCH and / or SRS.

[0346] An SRS resource set can be associated with a UL / joint TCI or SRI. In this case, the terminal can reuse the TA or TAG of the SRS resource set as is. The above operation can be applied when the UL signal / channel is referenced by the UL / joint TCI.

[0347] Method 7-9: Two or more SRS resource sets indicated by the same serving cell may be associated with different TAGs.

[0348] When a DL signal / channel is referenced by a UL / joint TCI, other DL signals / channels referenced by the DL signal / channel can be derived. By repeating the above operations, the SSB can be derived. The TAG can be derived from the TRP that sends the SSB. To support the above operations, the TRP identifier can be associated with the TAG. The base station can indicate the TRP identifier and / or TAG to the terminal through signaling (e.g., RRC signaling). The terminal can recognize the TRP identifier and / or TAG indicated by the base station.

[0349] Method 7-10: When using UL / joint TCI referenced by a DL signal / channel, the TAG can be derived from the TRP of the transmitted DL signal / channel.

[0350] The CORESET pool index can be used as a TRP identifier.

[0351] 8. UL gap indication method for each Tx panel

[0352] Communication systems operating in the FR2 band may adhere to maximum permissible exposure (MPE) regulations to control the RF exposure of terminals. In this case, predicting power management maximum power reduction (P-MPR) can be difficult. To prevent radio link failure and / or connection loss due to temporary UL power adjustments by terminals, improvements may be required in terminal operations.

[0353] The terminal can use a power headroom report (PHR) to report the P-MPR value to the base station. In order for the proximity sensor to operate accurately, it may be necessary to generate and / or configure certain gaps in FR2 communication. For the operation of the proximity sensor, an FR2 UL gap can be introduced.

[0354] When performing FR2 communication (for example, using a beam in the FR2 frequency band for transmission), the terminal can use a proximity sensor to determine whether a human body is near the terminal. When the terminal is not equipped with a proximity sensor, the terminal (for example, the terminal's transmitter) can control the transmit power so that the average transmit power does not exceed the limit within the time window. Based on the above operation, RF exposure regulations can be met. Based on the above operation, the maximum transmit power of the terminal can be reduced regardless of whether there is a human body around the terminal.

[0355] Because most Tx panels precisely configure beam direction, they can perform additional power adjustments based on proximity sensors when the human body is exposed to RF radiation. When high-power terminals (such as fixed wireless access (FWA) terminals using high transmit power) use proximity sensors, they can meet MPE regulations without constantly changing power. This improves not only the terminal's coverage range but also the user experience.

[0356] Calibration of terminals in the FR2 band may be more difficult than calibration of terminals in the FR1 band. RF may have nonlinear characteristics due to rapid changes in hardware temperature due to high processing rates, phase noise due to the use of wide bandwidth and / or high frequency, etc.

[0357] To address the I / Q mismatch problem, a UL gap can be introduced. In this case, the I / Q mismatch can be resolved with lower complexity. The UL gap can be used to estimate local oscillator (LO) leakage and / or intermediate frequency (IF) mixer DC offset.

[0358] When supporting FR2 single-cell, F2 inter-band CA, and / or F2 intra-band, the terminal may support UL gaps. In this case, the terminal may support at least one of gap pattern 1 or gap pattern 3 (e.g., UL measurement gap pattern (MGP) #1 or UL MGP #3). The terminal may support different gap patterns (e.g., UL MGP #0 or UL MGP #2 in Table 8 below) according to UE capabilities. Table 8 below shows the UL gap patterns.

[0359] [Table 8]

[0360]

[0361] The UL gap may include logically consecutive UL time slots. A UL time slot (e.g., a UL gap) may indicate a semi-statically configured upper UL time slot. A UL time slot (e.g., a UL gap) may not indicate a UL time slot including a dynamically indicated UL symbol. The UGL (e.g., the length of the UL gap) may be set in milliseconds. The number of UL time slots included in the UL gap may vary according to the subcarrier spacing (SCS). For UL MGP#0, the UGL may be 1 ms, and when an SCS of 30 kHz is applied, the UL gap may include two UL time slots. The two UL time slots included in the UL gap may not be (physically) consecutive.

[0362] Depending on the UE capability (e.g., tx-Support-UL-GapFR2), the terminal may or may not perform UL transmission in the UL time slot belonging to the UL gap. A terminal that supports the UE capability (e.g., tx-Support-UL-GapFR2) may transmit a UL signal / channel in the UL time slot belonging to the UL gap. A terminal that does not support the UE capability (e.g., tx-Support-UL-GapFR2) may not be able to transmit a UL signal / channel in the UL time slot belonging to the UL gap. Even if the UE capability (e.g., tx-Support-UL-GapFR2) is not supported, the UL signal / channel may be abnormally transmitted in the UL time slot belonging to the UL gap.

[0363] The UL signal / channel sent by the terminal in the UL gap may include HARQ-ACK, CSI, SRS and / or PUSCH (e.g., some PUSCH). Some PUSCHs may be CG PUSCH, Msg3 PUSCH and / or MsgA payloads. A terminal that does not support UE capabilities (e.g., tx-Support-UL-GapFR2) may be able to send CG PUSCH, Msg3 PUSCH and / or MsgA payloads, but when dynamic scheduling is received, the terminal may not be able to send CGPUSCH, Msg3 PUSCH and / or MsgA payloads in the UL time slot belonging to the UL gap. Therefore, the base station can determine that the terminal does not send UL signals / channels in the UL time slot (e.g., UL gap).

[0364] The base station may not schedule UL signals / channels in the UL gaps.In the proposed method, UL gaps may be indicated for each Tx panel.

[0365] Method 8-1: The base station may indicate two or more UL slots to the terminal. Each UL slot may have a different time slot offset (or a different subframe offset). One UL slot pattern may correspond to one Tx panel.

[0366] A base station may configure two or more UL gap patterns for a terminal. The terminal may recognize the two or more UL gap patterns configured by the base station. Association information between the UL gap pattern, Tx panel, UL / joint TCI, and / or spatial relationship information may be indicated to the terminal. Information regarding the UL gap pattern may include information regarding UL signals / channels. Alternatively, configuration information regarding the UL signals / channels may include information regarding the UL gap pattern. Transmission of UL signals / channels associated with the UL gap may be interpreted as canceled. Alternatively, transmission of UL signals / channels associated with the UL gap may be interpreted as permitted.

[0367] The base station may configure a UL gap pattern for the terminal. The terminal may recognize the UL gap pattern configured by the base station. The UL gap pattern may have an additional time slot offset (e.g., an additional subframe offset). The terminal may generate two or more UL gap patterns by applying the additional time slot offset (e.g., an additional subframe offset) to the UL gap pattern. Each UL gap pattern may be associated with a Tx panel, UL / joint TCI, and / or spatial relationship information. The transmission of a UL signal / channel associated with the UL gap may be interpreted as being canceled. Alternatively, the transmission of a UL signal / channel associated with the UL gap may be interpreted as being allowed.

[0368] 9. Consider DWS power headroom reporting methods

[0369] The terminal can report power headroom information to the base station. The base station can use this information to perform UL scheduling. The PHR can be included in a MAC CE. In other words, the PHR can be included in a TB in the form of a MAC CE. The terminal can send a MAC CE including the PHR on the PUSCH. The PHR can be expressed as a quantized value representing the difference between the maximum power and the required power for PUSCH transmission.

[0370] P CMAX，f，c (i.e., maximum power) can be derived from the frequency f of the serving cell c. CMAX,f，c It may be a value to which a maximum power reduction (MPR) is applied. The MPR may be determined taking into account the power class of the terminal, the allocation of PRBs in which the PUSCH is scheduled, the modulation order and / or waveform of the PUSCH. CMAX，f，c ,In addition to MPR, additional (A)-MPR and / or power management (P)-MPR can also be considered.

[0371] The power required for PUSCH transmission can be divided into the power of PUSCH transmission scheduled by the serving cell and the power of PUSCH transmission not scheduled by the serving cell. When a terminal supporting Carrying Out Carriers and / or Carrying Out Carriers performs simultaneous transmission, the PHR of the PUSCH not scheduled by the serving cell can be derived to inform the base station of the power headroom of the terminal.

[0372] When the terminal performs a scheduled PUSCH transmission, the terminal's transmit power (e.g., power headroom) may be calculated based on the active UL BWP of the serving cell that schedules the PUSCH transmission. To calculate the power of PUSCH transmissions not scheduled by the serving cell, the active UL BWP of the serving cell may be applied based on another reference. For example, Can replace P CMAX,f，c To calculate the power of PUSCH transmission, the number of allocated PRBs and / or the amount related to MCS may not be taken into account. In other words, the number of allocated PRBs and / or the amount related to MCS may be considered as 0.

[0373] The PHR may be triggered according to conditions defined in the technical specifications. Conditions for triggering the PHR may include when a timer expires, when the PHR is (re)configured via signaling (e.g., RRC signaling), when an SCell is activated, when a secondary cell group (SCG) is activated, and / or when a PSCell is added.

[0374] The timer can be a prohibit timer and / or a periodic timer. The prohibit timer can be used to temporarily allocate the PHR so that it is not triggered frequently. The periodic timer can be used to periodically trigger the PHR. Other conditions can be interpreted as various events related to the status change of the serving cell.

[0375] There can be two PHR formats. For example, the PHR format can be divided into a multi-entry PHR format and a single-entry PHR format. TwoPHRMode can be set. In the mTRP scenario, when the terminal performs repeated PUSCH transmission, due to different fading in the radio links, power control can be performed separately for each radio link. In this case, a PHR for each radio link may be required, and twoPHRMode can be set to support the above operation.

[0376] When using a multi-entry PHR format (e.g., when multiplePHR is set to "true" and is indicated to the terminal), the PHRs of all serving cells configured in the terminal can be derived. When twoPHRMode is indicated to the terminal, the terminal can derive two PHRs for one serving cell. If twoPHRMode is not indicated to the terminal, the terminal can derive one PHR for one serving cell.

[0377] When a single-entry PHR format is used (e.g., when the use of a multi-entry PHR format is not indicated), a PHR associated with the PCell may be derived. When twoPHRMode is indicated to the terminal, the terminal may derive two PHRs for the PCell. If twoPHRMode is not indicated to the terminal, the terminal may derive one PHR for the PCell.

[0378] Figures 12 to 18 A PHR MAC CE may be exemplified. The PHR MAC CE may be a MAC CE including a PHR.

[0379] Figure 12 is a conceptual diagram illustrating a first exemplary embodiment of a single-entry PHR MAC CE.

[0380] refer to Figure 12 , R may indicate a reserved bit. R may be fixed to 0. The size of the power headroom (PH) may be 6 bits. The PH level may be quantized according to a predefined standard.

[0381] Depending on whether mpe-Reporting-FR2 is configured, P can be interpreted differently. When mpe-Reporting-FR2 is set, the serving cell operates in the FR2 frequency band, P-MPR is applied, and the value of P-MPR is less than P-MPR_00, P can be expressed as 0. When the above conditions are not met, P can be expressed as 1. P-MPR_00 can be a value derived separately based on the technical specifications. When P-MPR is applied to meet MPE requirements, P-MPR_00 can be used. When mpe-Reporting-FR2 is not configured or when the serving cell operates in the FR1 frequency band, P can indicate whether power backoff occurs to support power management. When power backoff occurs, P can be expressed as 1. If no power backoff occurs, P can be expressed as 0.

[0382] P CMAX，f，c Can refer to the value used to derive pH. pH levels can be quantified according to predefined standards.

[0383] MPE can be interpreted differently depending on whether mpe-Reporting-FR2 is configured. When mpe-Reporting-FR2 is set, the serving cell operates in the FR2 band, and P is 1, MPE can indicate the power backoff applied to meet the MPE requirements. MPE can be represented as an index based on predefined criteria. When mpe-Reporting-FR2 is not configured or when the serving cell operates in the FR1 band, if P is 0, MPE can be represented as R.

[0384] The format of a multi-entry PHR can be as follows Figure 13 and Figure 14 shown.

[0385] Figure 13 is a conceptual diagram showing a first exemplary embodiment of a multi-entry PHR MAC CE, and Figure 14 is a conceptual diagram illustrating a second exemplary embodiment of a multi-entry PHR MAC CE.

[0386] refer to Figure 13 and Figure 14 , the multi-entry PHR format can have a variable size. The multi-entry PHR format may include a P including a bitmap, a Type 2 PH field, and a SpCell. CMAX，f，c The octet includes the Type 1 PH field and the PCell CMAX，f，c The multi-entry PHR format may include octets that include one or more Type 1 PH fields (or one or more Type 3 PH fields) and P_(CMAX, f, c) of the serving cells in the order of the serving cell index (ServCellIndex). CMAX，f,c field.

[0387] The size of the bitmap can be 8 bits or more. Figure 13 In an exemplary embodiment of , when 8 or fewer serving cells are configured (eg, when the maximum value of ServCellIndex is 8 or less), the bitmap may be represented in 1 octet. Figure 14 If more than 8 serving cells are configured in the exemplary embodiment of the present invention, the bitmap can be represented in 4 octets.

[0388] In order to determine the PH derived for the activated serving cell (eg, actual PH or reference PH), the PUSCH processing time and / or reception time indicated to the terminal via DCI or Configuration Grant (CG) may be considered.

[0389] For band combinations that do not support dynamic power sharing, the PH field and the P field of the serving cell may be omitted from the multi-entry PHR MAC CE. CMAX，f，c Exceptionally, information about a PCell belonging to another cell group (or another MAC entity) cannot be omitted from a multi-entry PHR MAC CE. The terminal may determine the PH and / or PHR by implementation. CMAX，f,c .

[0390] If there is a PH field for the serving cell i indicated by ServCellIndex, then C i Can be set to 1. If there is no PH field for the serving cell i indicated by ServCellIndex, then Ci Can be set to 0.

[0391] V may represent an actual PH or a reference PH. When information about PUSCH is transmitted in a type 1 PH, V may be expressed as 0. When a reference PH is used, V may be expressed as 1. When information about PUCCH is transmitted in a type 2 PH, V may be expressed as 0. When a reference PH is used, V may be expressed as 1. When information about SRS is transmitted in a type 3 PH, V may be expressed as 0. When a reference PH is used, V may be expressed as 1. Setting V to 0 may mean that there is a PUSCH in a multi-entry PHR MAC CE. CMAX，f，c V set to 1 may mean that the octet containing the PHR field is omitted in the multi-entry PHR MAC CE. CMAX,f,c field and the octet of the MPE field.

[0392] When MPE occurs, the MPE resource can be indicated separately. In this case, the improved PHR can be applied. The improved PHR can be as follows: Figure 15 to Figure 1 7.

[0393] Figure 15 is a conceptual diagram illustrating a first exemplary embodiment of an improved single-entry PHR MAC CE.

[0394] refer to Figure 15 , when considering the improved single-entry PHR MAC CE, B i and resources i Can be additionally considered. The base station may indicate mpe-ResourcePoolToAddModList to the terminal through signaling (e.g., RRC signaling), and may indicate SSB or CSI-RS through a 6-bit index. When MPE occurs, resources i It can be used to use SSB or CSI-RS as candidate beams.

[0395] Figure 16a and Figure 16b is a conceptual diagram illustrating a first exemplary embodiment of an improved multi-entry PHR MAC CE, Figure 17a and Figure 17b is a conceptual diagram illustrating a second exemplary embodiment of an improved multi-entry PHR MAC CE.

[0396] refer to Figure 16a 、 Figure 16b 、 Figure 17a and Figure 17b , an improved multi-entry PHR MAC CE may be considered. A first exemplary embodiment of the improved multi-entry PHR MAC CE may include Figure 16a16B . Figure 16a The last information element (e.g., the last octet) shown in Figure 16b A second exemplary embodiment of the improved multi-entry PHR MAC CE may include Figure 17a The information elements (e.g., octets) shown in Figure 17b The information elements (e.g., octets) shown in . Figure 17a The last information element (eg, the last octet) shown in FIG. 17A may be adjacent to the first information element (eg, the first octet) shown in FIG. 17B .

[0397] When the terminal performs CA operation, the improved multi-entry PHR MAC CE can be applied. If the maximum value of ServCellIndex configured in the terminal is 8 or less, the improved multi-entry PHR MAC CE can be applied. Figure 16a and Figure 16b If the maximum value of ServCellIndex configured in the terminal exceeds 8, the improved multi-entry PHRMAC CE can be applied. Figure 17a and Figure 17b The improved multi-entry PHR MAC CE shown in .

[0398] When two UL carriers are configured for a terminal in a serving cell, the serving cell may determine a Type 1 PHR and / or a Type 3 PHR. The Type 1 PHR and the Type 3 PHR may have the same format (e.g., actual format or reference format). Alternatively, the Type 1 PHR and the Type 3 PHR may have different formats. When the Type 1 PHR and the Type 3 PHR have the same format, the Type 1 PHR may be derived. When the Type 1 PHR and the Type 3 PHR have different formats, the PHR with the actual format may be derived.

[0399] according to Figure 12 to Figure 1 According to the exemplary embodiment of FIG. 7 , one PH for the PHR MAC CE may be generated in one serving cell.

[0400] The terminal can repeatedly send PUSCH to two TRPs. In this case, it can be considered Figures 18 to 20 .

[0401] Figure 18 is a conceptual diagram illustrating a first exemplary embodiment of an improved single-entry PHR MAC CE for multiple TRPs.

[0402] refer to Figure 18, the improved single-entry PHR MAC CE can be supported in two TRPs. A PHR including two PHs for one serving cell can be generated. The base station can configure two or more SRS resource sets of identifiers (IDs) to the terminal through signaling (e.g., RRC signaling). The two or more IDs can be distinguished from each other. The terminal can select an SRS resource set for the two IDs and derive a PH for the selected SRS resource set. Figure 18 In an exemplary embodiment of , PH 1 may be derived from the SRS resource set associated with the lower of the two IDs, and PH 2 may be derived from the SRS resource set associated with the higher of the two IDs. CMAX,f,c Can represent a value commonly applied to PH 1 and PH 2.

[0403] Figure 19 is a conceptual diagram illustrating a first exemplary embodiment of an improved multi-entry PHR MAC CE for multiple TRPs, Figure 20 is a conceptual diagram illustrating a second exemplary embodiment of an improved multi-entry PHR MAC CE for multiple TRPs.

[0404] refer to Figure 19 and Figure 20 , can support the improved multi-entry PHR MAC CE in two TRPs. When the terminal performs CA operation, the improved multi-entry PHR MAC CE can be applied. When the maximum value of ServCellIndex configured in the terminal is 8 or less, it can be applied Figure 19 When the maximum value of ServCellIndex configured in the terminal exceeds 8, you can apply Figure 20 When a serving cell indicates an SRS resource set to a terminal, some octets may be omitted from the improved multi-entry PHR MAC CE. For example, some optional information elements (e.g., optional fields, optional octets) may be omitted from the improved multi-entry PHR MAC CE.

[0405] If the waveform of PUSCH changes, P CMAX,f，c may change, and the change of P CMAX,f,c Can also be applied. CMAX,f，c The reason for the change may be that the MPR, A-MPR and / or P-MPR may change according to the waveform, modulation order, frequency band combination and / or PRB allocation of the PUSCH. Therefore, scheduling to change the waveform may be a condition for triggering PHR.

[0406] Method 9-1: When the scheduling information for the initial transmission of the TB is received, the scheduling of changing the waveform can be regarded as a triggering condition of the PHR.

[0407] When the base station schedules a PUSCH to the terminal and a TB is retransmitted, the retransmitted TB may be the same as the previously transmitted TB. In this case, even if a PHR is triggered, the PHR may not be reflected in the transmission of the TB (for example, the retransmission of the TB). If the decoding of the initially transmitted TB fails, the base station may send an indication of the retransmission of the TB and an indication of the waveform change to the terminal. In this case, when method 9-1 is applied, the initially transmitted TB may include a triggered PHR.

[0408] A method of reporting one PH in one serving cell may be considered. When receiving scheduling information from the serving cell, the terminal may derive a PHR based on the waveform indicated by the scheduling information. The above operations can be summarized as follows. For example, one PH may be generated in the serving cell (or two PHs in the mTRP scenario). Alternatively, a PHR may be generated for each serving cell. The terminal may send either a PH or a PHR on the PUSCH.

[0409] Method 9-2: The terminal may report a PHR. The terminal may assume the waveform indicated by the scheduling information and derive the PHR in the actual format applied.

[0410] A PHR may include different fields, including the reported PH and P CMAX，f，c In this case, one or more PHRs may be reused. Alternatively, one PHR may include different fields, including PH and P CMAX，f，c .

[0411] Preferably, the base station triggers the PHR for the CP-OFDM-based PUSCH and the PHR for the DFT-s-OFDM-based PUSCH without changing the PUSCH waveform. The base station may receive two PHRs for one serving cell and determine whether to perform a waveform change operation based on the two PHRs.

[0412] Method 9-3: The terminal may report two PHs. Assuming that different waveforms exist in the same serving cell (or UL BWP), corresponding PHs may be generated.

[0413] A PH can be derived for each waveform. For a reference waveform, a PH based on the actual format can be derived. For another waveform, a PH based on the reference format can be derived. The reference waveform can be a waveform associated with the UL BWP. Alternatively, the reference waveform can be indicated via RRC signaling.

[0414] When the PH is derived for each waveform, the actual format or the reference format may be applied to all PHs.

[0415] If the PH is derived for each waveform, the scheduling information may not be valid for the waveform. Scheduling not assumed in DFT-s-OFDM can allocate PUSCH based on CP-OFDM. Since a multi-carrier waveform is used in the case of CP-OFDM, frequency resources including non-contiguous PRBs can be allocated. Since a single-carrier waveform is used in the case of DFT-s-OFDM, frequency resources including contiguous PRBs can be allocated. Since single-layer transmission is performed in the case of DFT-s-OFDM, combinations that do not allow DM-RS port mapping can be valid combinations in CP-OFDM.

[0416] The waveform may be divided into a waveform indicated by the scheduling information (eg, an actual waveform) and an alternative waveform (eg, a hypothetical waveform or a substitute waveform).

[0417] When invalid scheduling information is indicated in the replacement waveform, the terminal may perform an operation to generate a PH (e.g., PHR) for the actual waveform. The generation operation may include an operation in which the terminal recalculates all values constituting the PHR. The terminal may not recalculate the PH (e.g., PHR) for the replacement waveform. The terminal may transmit the PH (e.g., PHR) for the replacement waveform on the PUSCH. The terminal may not perform a new PH (e.g., PHR) calculation for the replacement waveform. The terminal may not transmit the PH (e.g., PHR) for the replacement waveform on the PUSCH.

[0418] Method 9-4: Even when the scheduling information of the alternative waveform is invalid, the PH (eg, PHR) for the alternative waveform may be transmitted on the PUSCH.

[0419] The terminal may not perform new calculations for the replaced waveform. Therefore, the base station may consider the PH (e.g., PHR) as virtual. The terminal may send the unupdated PH (e.g., PHR). Alternatively, the terminal may consider the unupdated PH (e.g., PHR) as reserved. The terminal may send unnecessary payload, but since the base station considers the size of the PHR MAC CE to be constant, processing can be simplified.

[0420] Method 9-5: When the scheduling information for the alternative waveform is invalid, the PH (eg, PHR) of the alternative waveform may be dropped from the PUSCH.

[0421] Invalid PH (e.g., PHR) may not be included in the PUSCH. Since scheduling information is sent through DCI, the MAC layer may not be aware of the scheduling information. Therefore, an additional bit can be introduced in the improved PHR MAC CE to distinguish between traditional PH (e.g., PHR) and improved PHR.

[0422] A bit can be added to the PHR for each serving cell. This bit can indicate whether the PH of the alternative waveform exists or not. Alternatively, this bit can indicate whether the PH of the alternative waveform has been updated.

[0423] Method 9-6: When a bit of the PHR has a first value, the bit having the first value may mean that the PHR includes a PH for the actual waveform (e.g., a legacy PH). When the bit of the PHR has a second value, the bit having the second value may mean that the PHR additionally includes a PH for an alternative waveform.

[0424] Method 9-7: When a bit of the PHR has a first value, the bit having the first value may indicate that an updated PH for the replacement waveform is included in the PHR. When the bit of the PHR has a second value, the bit having the second value may indicate that the PH (e.g., PHR) for the replacement waveform does not need to be updated.

[0425] The terminal can derive PH for the CP-OFDM-based PUSCH and the DFT-s-OFDM-based PUSCH respectively. The PH of the CP-OFDM-based PUSCH can be referred to as "PH(CP-OFDM)". The PH of the DFT-s-OFDM-based PUSCH can be referred to as "PH(DFT-s-OFDM)". When one PHR includes PH(CP-OFDM) and PH(DFT-s-OFDM), PH(CP-OFDM) and PH(DFT-s-OFDM) can be arranged in a predefined order within one PHR. The predefined order may refer to the order in which PH(CP-OFDM) and PH(DFT-s-OFDM) are included in octets. The predefined order may refer to the order of octets belonging to the PHR.

[0426] The order of the PH (CP-OFDM) and PH (DFT-s-OFDM) can be derived based on signaling (e.g., RRC signaling). The base station can use signaling (e.g., RRC signaling) to indicate to the terminal the waveform associated with the UL BWP. In this case, information about the waveform associated with the UL BWP (e.g., PH) can be arranged first or later in the PHR.

[0427] The PH for a waveform (eg, actual waveform) applied to the scheduled PUSCH may be arranged first or later within the PHR.

[0428] Method 9-8: In method 9-3, the order (e.g., permutation order) of PH (CP-OFDM) and PH (DFT-s-OFDM) may be determined based on the UL BWP. Alternatively, in method 9-3, the order (e.g., permutation order) of PH (CP-OFDM) and PH (DFT-s-OFDM) may be determined based on the scheduling DCI.

[0429] For a PHR including two PHs, a P can be generated for each PH. CMAX，f，c Alternatively, for a PHR consisting of two PHs, one P CMAX，f，c , and a P CMAX，f，c Can be included in PHR. For example, when PH(CP-OFDM) and PH(DFT-s-OFDM) are derived using the actual format, P CMAX，f，c It can be derived from other values. In this case, each PH can be considered including P CMAX，f，c PHR.

[0430] Method 9-9: In Method 9-3, the P of each PH CMAX，f，c Both can be included in the PHR.

[0431] In order to reduce the number of octets included in the PHR, the terminal may include the P of the reference PH in the PHR. CMAX，f，c , and the P of another PH may not be included in the PHR CMAX，f，c A distinction can be made between the case where the actual format is considered and the case where the reference format is considered.

[0432] When considering the actual format, different P CMAX，f，c Can be used to derive PH. For example, the reference PH can be PH(CP-OFDM). CMAX，f，c Can be included in PHR. PH (DFT-s-OFDM) can be based on another P CMAX，f，c The PH (DFT-s-OFDM) can be omitted from the PHR. In this case, the PH (CP-OFDM) can be included in the PHR. The base station can use the PH (CP-OFDM) and P CMAX，f，c To estimate the path loss, P can be obtained based on the path loss and PH (DFT-s-OFDM) CMAX，f，c When the reference PH is PH(DFT-s-OFDM), the above operation can be used to obtain P CMAX，f，c .

[0433] When considering the reference format, the same value may be derived for all PHs. In this case, one PH may be included in the PHR. Alternatively, PHs with the same value may be included in the PHR. In other words, PHs with the same value may be redundant in the PHR.

[0434] Method 9-10: In Method 9-3, a PH of P CMAX，f，c Can be included in PHR.

[0435] The PH of the actual format can be derived in the serving cell that transmits PUSCH. The PH of the reference format can be derived in the serving cell that does not transmit PUSCH. When the reference format is applied, the PRB allocation can not be derived, MPR / A-MPR / P-MPR=0 can be assumed, and P can be derived. CMAX，f，c In order to derive a PH including a large amount of information on the non-scheduled PUSCH, a virtual transmission format agreed upon between the terminal and the base station may be required.

[0436] Methods 9-11: The terminal may derive the PH by applying a reference format based on a virtual transmission assumption.

[0437] The transmission hypothesis may mean a resource allocation including at least a specific PRB allocation, a specific modulation order, and a specific waveform.

[0438] According to the technical specifications, in order to derive the PH based on the reference format, the amount of allocated resources can be minimized, and a transmission hypothesis without waveform characteristics can be applied. Therefore, it may be preferable that the base station uses signaling (e.g., RRC signaling) to send an instruction to the terminal to apply a new transmission hypothesis. The terminal can apply the new transmission hypothesis based on the instruction from the base station. The new transmission hypothesis can have a resource allocation defined in the technical specifications. The new transmission hypothesis can refer to a specific resource allocation indicated by reference signaling (e.g., RRC signaling).

[0439] According to another method, the terminal can use a virtual transmission assumption and apply the resource allocation of another serving cell where scheduling occurs. Since the terminal transmits PUSCH in at least one serving cell, the terminal can send a PHR to the base station. Based on the resource allocation of PUSCH, the PH and PHR used to determine the serving cell can be applied. CMAX,f，c The reference format can be applied to other serving cells.

[0440] Depending on the waveform, it may be necessary to generate two or more PHs for the serving cell. In this case, the terminal can derive the PH and PH by applying the resource allocation of another serving cell where scheduling occurs. CMAX，f，cWhen scheduling occurs in multiple other serving cells, the terminal can select a serving cell from the multiple other serving cells and apply the resource allocation of the selected serving cell to derive PH and P CMAX，f，c For example, the terminal may select a serving cell having the largest or smallest identifier among multiple other serving cells based on ServCellIndex.

[0441] Method 9-12: The terminal can obtain the PH and P of the serving cell that is not scheduled by applying the resource allocation of another serving cell that is scheduled. CMAX，f，c .

[0442] The base station may instruct the terminal to perform a PH derivation method based on the reference format. The terminal may perform the 'PH derivation method based on the reference format' instructed by the base station.

[0443] Method 9-13: The base station may indicate one scheme for the reference format to the terminal through signaling (eg, RRC signaling). The terminal may recognize one scheme for the reference format indicated by the signaling from the base station.

[0444] The base station can set twoPHRMode to the terminal. When twoPHRMode is set in the terminal, the terminal can obtain two PHs and one P for the serving cell. CMAX，f，c In order to compensate for the path loss when performing repeated PUSCH transmission, the terminal can transmit two PHs to the base station. According to method 9-3, the PH according to the waveform can be used as the PHR. According to method 9-10, even if the terminal uses different P CMAX,f,c Two PHs are obtained, and the terminal can also transmit a P CMAX,f，c Due to the above limitations, the terminal can transmit the PHR including the PHR for the reference waveform based on the rules pre-defined between the terminal and the base station. CMAX,f,c PHR.

[0445] When no scheduling occurs in the serving cell, the terminal can derive a PH based on the reference format. In this case, it may be preferable not to use a PH that does not reflect waveform characteristics. According to methods 9-13, the terminal can identify a scheme for the reference format indicated by signaling from the base station (e.g., RRC signaling). The terminal can generate a PH by applying the resource allocation and transmission assumptions of another serving cell. Alternatively, the terminal can generate a PH by applying a separately indicated resource allocation or a predefined resource allocation.

[0446] 10. Multi-cell and cross-carrier scheduling methods considering DWS

[0447] A DCI format can include scheduling information for two or more serving cells. For example, DCI format 1_3 can be used for downlink communication of two or more serving cells. DCI format 0_3 can be used for uplink communication of two or more serving cells.

[0448] For ease of description, DCI fields can be divided into Type-1 fields, Type-2 fields, Type-3 fields, etc. Type-1 fields can be divided into Type-1A fields, Type-1B fields, and Type-1C fields. In other words, the Type-1 field can include at least one of the Type-1A field, the Type-1B field, or the Type-1C field. The Type-1A field can represent common information for all scheduled serving cells. The Type-1B field can be a joint indicator. The Type-1C field can represent information about one serving cell among the scheduled serving cells.

[0449] The Type-2 field can be interpreted as individual fields (e.g., individual information) for the corresponding scheduled serving cell. Alternatively, the Type-2 field can be interpreted as individual fields for the corresponding subgroup of scheduled serving cells. In this case, each Type-2 field can be interpreted as common information about the serving cells belonging to each subgroup. The Type-3 field can be interpreted as common information or individual information for each scheduled serving cell or serving cell of a subgroup.

[0450] DL DCI format (e.g., DL-related DCI format) and UL DCI format (e.g., UL-related DCI format) may include different fields, but in the DL DCI format and the UL DCI format, the fields may be divided into type-1A field, type-1B field, type-1C field, type-2 field, and type-3 field.

[0451] The Type-1A field may include an identifier of the DCI format, a downlink allocation index, a TPC of the scheduled PUCCH, a PUCCH resource indicator, a PDSCH to HARQ timing indicator, a one-time HARQ-ACK request, a BWP indicator, a VRB to PRB mapping, a PRB bundling size indicator, a frequency hopping flag, an open-loop power control parameter set indication, a DMRS sequence initialization, an improved type-3 codebook indicator, a HARQ-ACK retransmission indicator, a PUCCH cell indicator, a priority indicator, a ChannelAccess-Cpext, a ChannelAccess-Cpext-CAPC, or at least one of a beta_offset indicator.

[0452] The Type-1B field may include at least one of a rate matching indicator, a zero power (ZP) CSI-RS trigger, a TCI, an SRS request, or an SRS offset indicator.

[0453] The Type-2 field may include at least one of a new data indicator (NDI) for each TB, a redundancy version (RV) for each TB, an MCS, a HARQ process number (HPN), a frequency domain resource allocation (FDRA), a TPC command for a scheduled PUSCH, or a PTRS-DMRS association.

[0454] The Type-3 field may include at least a CSI request.

[0455] The field that can be configured as a Type-1A field and / or a Type-2 field may include at least one of an antenna port, precoding information and layer number, an SRS Resource Indicator (SRI), or a UL / Joint TCI.

[0456] The index of the serving cell reflecting the scheduling information may be indicated by one field or a combination of two or more fields in the DCI format. The base station may use signaling (e.g., high-layer signaling) to notify the terminal of the index corresponding to the serving cell. The terminal may identify the index corresponding to the serving cell indicated by the base station. The high-layer signaling may include RRC signaling.

[0457] The index of a serving cell can be indicated through a two-step process. For example, the base station may use signaling (e.g., high-layer signaling) to indicate a set of serving cells to the terminal, and use signaling (e.g., high-layer signaling) to indicate to the terminal which index corresponds to one or more serving cells in the set. The scheduled cell set indicator may indicate a set of serving cells, and the scheduled cell indicator may indicate one or more serving cells belonging to the set of serving cells.

[0458] When all serving cells are in an active state, the DCI format can be used to perform scheduling for the active BWP. Some of the serving cells configured or indicated in the terminal may be deactivated. The deactivation of a serving cell may be indicated by a MAC CE, and the serving cell set and / or serving cell index may be indicated by signaling (e.g., RRC signaling). When the index of a serving cell is always indicated only by a combined index, scheduling information for a deactivated serving cell may be indicated. Since the scheduling information may be applied to an activated serving cell, a method for solving the above problem is needed.

[0459] Method 10-1: The terminal may assume that all serving cells scheduled by one DCI format are active.

[0460] When all serving cells are activated, the terminal may consider that it has received a DCI format including scheduling information for all serving cells. If it is not possible to use a serving cell set and a serving cell index to indicate any serving cell, the scheduling information may be scheduling information for serving cells including deactivated serving cells.

[0461] To prevent this from happening, the fields indicating the serving cell set and serving cell index can be configured to be sufficiently large. In this case, the size of the DCI can be increased. Increasing the size of the DCI may cause other problems. A process that the terminal should perform when scheduling information is invalid can be proposed.

[0462] Method 10-2: The terminal may reflect the scheduling information in an activated serving cell among the scheduled serving cells, and may not reflect the scheduling information in a deactivated serving cell.

[0463] The scheduling information may include fields including the DWS field. The fields included in the scheduling information may not be supported in certain serving cells and / or certain BWPs. The following method is applicable not only to the DWS field, but also to other fields (e.g., other information).

[0464] The DCI format including the DWS field can be configured or indicated to the terminal on a BWP basis. When considering multi-cell scheduling information, if the DWS function is supported in the UL BWP of each scheduled serving cell, the DWS field can be interpreted.

[0465] DCI (e.g., DCI format) may include scheduling information for multiple serving cells. Such scheduling information may include a DWS field. In this case, the terminal may interpret the DWS field based on the BWP.

[0466] For ease of description, a distinction can be made between the scheduling serving cell (e.g., serving cell 0, the serving cell from which DCI is received) and the scheduled serving cell. If the DL BWP in serving cell 0 does not change, the DCI format may not change because the CORESET and search space set do not change. In the scheduled serving cell, the DL BWP can be changed based on scheduling information, and the above operation can represent enabling / disabling the DWS function.

[0467] The DWS field of each scheduled serving cell may be included in the DCI. In this case, the DWS function of each scheduled serving cell may be controlled by serving cell 0. Among the active UL BWPs of the serving cell, there may be an active UL BWP that is not configured or does not indicate the DWS function. In this case, the terminal may ignore the above information (e.g., the DWS field).

[0468] Method 10-3: When the DWS function is not configured in the active UL BWP of a certain serving cell among the scheduled serving cells, the DWS information (eg, the value of the DWS field) on the active UL BWP of the serving cell indicated by the scheduling information may be ignored.

[0469] The DWS field (eg, DWS information) of the BWP that configures or indicates the DWS function may not be included in the scheduling information. In this case, a method for obtaining the DWS information may be required.

[0470] Method 10-4: When the DWS function is configured for the active UL BWP of a certain service cell among the scheduled service cells, but the scheduling information does not include the DWS field of the active UL BWP of the certain service cell, the value of the DWS field for the active UL BWP (e.g., the waveform indicated by the DWS field) can be interpreted as a waveform associated with a specific value (e.g., 0 or 1), a value configured (or indicated) by signaling (e.g., higher layer signaling) taking the above situation into account, or an active UL BWP.

[0471] The proposed method can be applied to cross-carrier scheduling and multi-cell scheduling. For example, in cross-carrier scheduling, fields for all BWPs for all scheduled serving cells (e.g., DWS fields) can be included in scheduling information (e.g., DCI). Some of the above fields can indicate to the terminal information that is not supported in the active BWP. When applying method 10-3, the terminal can ignore this information (e.g., information not supported in the active BWP) and use only valid information to interpret the scheduling information.

[0472] For example, considering a group of scheduled serving cells, a DWS field (e.g., a DWS field for a group of serving cells) may be included in the scheduling information. This group of serving cells may be referred to as a serving cell group. A value in the DWS field may indicate a waveform in the active UL BWP of a serving cell belonging to the serving cell group. The serving cell group may be the same as or different from the serving cell set indicated by the scheduling information. If the serving cell group and the serving cell set are different, the base station may use signaling (e.g., higher-layer signaling) to indicate the serving cell group to the terminal.

[0473] Since the aggregated serving cells in a terminal are not always located in the same TRP (or base station or antenna site), a serving cell group can be introduced. To reduce PAPR / intermodulation distortion (IMD) and increase PUSCH coverage, a DWS function can be configured or indicated for each UL BWP. It may be preferable to consider serving cells belonging to the same TRP and / or UL BWPs associated with the same TRP to share large-scale fading.

[0474] Method 10-5: A serving cell group (or carrier group, BWP group) sharing DWS information (e.g., DWS field) may be introduced, and the base station may configure or indicate the serving cell group to the terminal using signaling (e.g., higher-layer signaling). The terminal may identify the serving cell group indicated by the base station.

[0475] Method 10-6: In method 10-5, information of the same field (eg, the same DWS field) included in the DCI format may be applied to serving cells belonging to the same TRP.

[0476] 11. Consider PH reporting methods for STxMP

[0477] The terminal can send two or more SRSs. SRS can be widely used to compensate for the overall fast fading in the uplink. The SRS configuration (e.g., SRS-Config) can be as follows: Figures 21 to 23 shown.

[0478] Figure 21 is a conceptual diagram illustrating a first exemplary embodiment of an SRS configuration based on Rel-15 NR technical specifications.

[0479] refer to Figure 21 In a communication system supporting the Rel-15 NR technical specification, an RRC parameter (e.g., SRS-Config) may indicate multiple SRS resource sets. The SRS resource set may include a parameter "usage." The parameter "usage" included in the SRS resource set may indicate a resource set related to PUSCH transmission (e.g., an SRS resource set) and / or a separate SRS resource set for UL beam management or antenna switching.

[0480] The SRS configuration may indicate a resource set (e.g., an SRS resource set) for one of codebook-based PUSCH transmission and non-codebook-based PUSCH transmission. The number of SRS resource sets may be 1. The number of SRS resource sets indicated for antenna switching or beam management may be one or more.

[0481] Figure 22 is a conceptual diagram illustrating a first exemplary embodiment of an SRS configuration based on Rel-16 NR technical specifications.

[0482] refer to Figure 22 In a communication system supporting Rel-16 NR technical specifications, a separate SRS resource set can be indicated for positioning purposes, and all functions according to Rel-15 NR technical specifications can be supported. The number of SRS PosResource sets indicated to the terminal can be one or more.

[0483] Figure 23 is a conceptual diagram illustrating a first exemplary embodiment of an SRS configuration based on the Rel-17 NR technical specification.

[0484] refer to Figure 23 In a communication system supporting the Rel-17 NR technical specification, the number of SRS resource sets used for PUSCH transmission can be 1 or 2. In order to support the sDCI-based mTRP scenario, PUSCH transmissions for two TRPs can correspond to SRS resource sets on different links, respectively. For the above configuration, the method of using one SRS resource set in a communication system supporting the Rel-15 / 16 NR technical specification can be extended, one SRS resource set can correspond to each TRP, and power control, TPMI, SRI and / or TCI (for example, joint / UL TCI or TCI) for each TRP can be controlled separately.

[0485] The base station may indicate the second SRS resource set to the terminal. The terminal may identify the second SRS resource set indicated by the base station. The second SRS resource set may be used in an sDCI-based mTRP scenario and / or an mDCI-based mTRP scenario.

[0486] In a communication system that supports Rel-15 / 16 / 17NR technical specifications, the base station may indicate an SRS resource set associated with PUSCH transmission to the terminal. The terminal may identify an SRS resource set indicated by the base station. In codebook-based PUSCH transmission, the SRS resource set may include one or two SRS resources. SRS resources may have four or fewer antenna ports. In non-codebook-based PUSCH transmission, the SRS resource set may include 1, 2, 3, or 4 SRS resources. SRS resources may have one antenna port. The number of antenna ports of the SRS resource may be scheduled to be directly or indirectly associated with the PUSCH DM-RS port. Since the maximum number of PUSCH DM-RS ports is 4 and the number of TBs is 1, the number of antenna ports that the SRS resource has is limited.

[0487] In a communication system supporting the Rel-18 NR technical specification, the maximum number of PUSCH DM-RS ports may be 8, and the maximum number of TBs may be 2. In codebook-based PUSCH transmission, an SRS resource set may include two or fewer SRS resources. An SRS resource may have 8 or fewer antenna ports. In non-codebook-based PUSCH transmission, an SRS resource set may include 1, 2, 3, 4, 5, 6, 7, or 8 SRS resources. An SRS resource may have one antenna port. The number of antenna ports of an SRS resource may be scheduled to be directly or indirectly associated with a PUSCH DM-RS port.

[0488] SRS (e.g., SRS resources, SRS transmission) can be discarded. Discarding SRS can mean not sending SRS. Discarding SRS resources can mean that SRS is not sent in SRS resources. Depending on the priority of the UL signal / channel and the SRS resource, the SRS resource can be discarded. In this case, SRS can be sent in the SRS resources that are not discarded. When a certain SRS resource is discarded, all SRS symbols belonging to the SRS resource can be discarded. An SRS symbol may refer to a symbol on which SRS transmission is performed. In other words, SRS transmission will not be performed on all SRS symbols belonging to the discarded SRS resource. Alternatively, if some SRS symbols belonging to the SRS resource overlap with the UL signal / channel, SRS can be sent in the remaining SRS symbols.

[0489] When PUCCH and SRS transmissions are performed on the same carrier, and semi-persistent SRS or periodic SRS transmissions are performed on the same symbol as PUCCH transmissions under certain conditions, SRS transmissions may not be performed. PUCCH transmissions may include CSI reports, L1-RSRP reports, or L1-SINR reports. When PUCCH transmissions include HARQ-ACK, link recovery requests, and / or scheduling requests (SRs), semi-persistent SRS, periodic SRS, or triggered SRS transmissions are not performed on the same symbol as PUCCH transmissions.

[0490] When SRS is not transmitted, only SRS symbols overlapping with PUCCH symbols performing PUCCH transmission may be discarded (e.g., SRS may be transmitted only in SRS symbols). When aperiodic SRS transmission is performed, PUCCH may not be transmitted. In this case, PUCCH may include a semi-persistent CSI report, a static CSI report, a semi-persistent L1-RSRP report, a static L1-RSRP report, a semi-persistent L1-SINR report, and / or a static L1-SINR report.

[0491] SRS may be transmitted simultaneously with other UL signals / channels.

[0492] Inter-band continuous CA, inter-band non-contiguous CA band combinations, or intra-band non-contiguous CA band combinations may be considered. The terminal may not support simultaneous transmission of SRS and PUCCH / PUSCH. In this case, the terminal may not be instructed to transmit PUSCH / UL DM-RS / UL PT-RS / PUCCH and SRS on different carriers and / or in the same symbol.

[0493] Intra-band contiguous CA or inter-band CA band combinations can be considered. The terminal may not support simultaneous transmission of SRS and PRACH. Alternatively, in intra-band non-contiguous CA band combinations, it may be considered not to indicate specific RRC parameters (e.g., intraBandNC-PRACH-simulTx-r17) to the terminal. In this case, the terminal may not be instructed to transmit SRS and PRACH simultaneously on different carriers.

[0494] Intra-band continuous CA or inter-band CA band combinations may be considered. The terminal may not support simultaneous transmission of SRS and MsgA. In this case, the terminal may not be instructed to send SRS and MsgA simultaneously on different carriers.

[0495] The terminal transmits the SRS in one SRS resource. In certain cases, the terminal may transmit the SRS simultaneously on two or more SRS resources. The terminal may transmit the SRS in an SRS resource belonging to an SRS resource set for beam management (e.g., a BM-SRS resource). The SRS may be transmitted in overlapping symbols between SRS resources. SRS resources may overlap in certain symbols.

[0496] SRS can be transmitted simultaneously in BM-SRS resources. In this case, when the transmit power of SRS does not exceed the maximum transmit power supported by the terminal, the transmit power of SRS (e.g., the transmit power for BM-SRS resources) can be determined based on technical specifications. The terminal can use the path loss (PL) RS associated with the BM-SRS resource to derive the path loss, perform open-loop power control by compensating for a portion of the path loss, and perform closed-loop power control based on the accumulation of TPC commands obtained from the DCI. When the transmit power of the terminal is equal to or greater than the maximum transmit power supported by the serving cell or BWP, the terminal can use the maximum transmit power to transmit BM-SRS.

[0497] When SRS is transmitted simultaneously in BM-SRS resource i (i=1, 2), the sum of the transmit powers (Pi, i=1, 2) required for simultaneous SRS transmission can be greater than the maximum transmit power. When SRS is transmitted simultaneously in an SRS resource set and a BM-SRS resource, the power (e.g., transmit power) of the SRS can be allocated based on the following method.

[0498] In the proposed method, the terminal can select one SRS resource (e.g., SRS resource 1), allocate sufficient power P1 to the one SRS resource, and allocate the remaining power P2 to the remaining SRS resources (e.g., SRS resource 2). The remaining power can be (the maximum power of the terminal (e.g., maximum transmit power) - P1). Alternatively, the remaining power can be less than (the maximum power of the terminal (e.g., maximum transmit power) - P1). The above method can be applied to SRS transmission (e.g., SRS resource) using one Tx panel.

[0499] Method 11-1: For simultaneous transmission of SRSs, one SRS resource set may be selected, SRS resources belonging to the selected SRS resource set may be associated with sufficient power, and other SRS resources may be associated with reduced power.

[0500] The selected SRS resource set may be indicated to the terminal via at least one of RRC signaling or scheduling DCI. For example, the selected SRS resource set may be indicated via a combination of RRC signaling and scheduling DCI. Alternatively, the SRS resource set may be selected based on a technical specification. For example, the first indicated SRS resource set may be selected. Alternatively, an SRS resource set with a smaller SRS resource set ID may be selected. The terminal may consider power allocation for the SRS resource set (e.g., the selected SRS resource set).

[0501] In the proposed method, a terminal may use two or more Tx panels to transmit an SRS. The SRS may be received at one TRP or at two or more TRPs. When the SRS is received at two or more TRPs, an SRS resource may be selected from each of the two or more SRS resource sets, and the SRS may be transmitted to each TRP in each selected SRS resource.

[0502] For the convenience of description, these two SRS resource sets may be respectively referred to as “SRS resource set (or first SRS resource set)” and “second SRS resource set”.

[0503] Method 11-2: To support the mTRP scenario, a second SRS resource set may be additionally indicated to the terminal through signaling from the base station.

[0504] The SRS resource set used to support the mTRP scenario may be different from the SRS resource set used to support the single TRP scenario. In this case, the SRS resource set supporting the single TRP may be called differently from the first SRS resource set and the second SRS resource set supporting the mTRP scenario. The SRS resource set and the first SRS resource set may be indicated to the terminal separately.

[0505] Method 11-3: In order to support the mTRP scenario, the SRS resource set and the first SRS resource set can be distinguished, and the SRS resource set and the first SRS resource set can be indicated to the terminal through signaling of the base station.

[0506] The SRS resource set used to support the mTRP scenario may be referred to as an SRS resource set pair. The SRS resource set pair may include a first SRS resource set and a second SRS resource set. Alternatively, the SRS resource set pair may include an SRS resource set and a second SRS resource set.

[0507] Method 11-4: In order to support the mTRP scenario, the SRS resource set pair can be indicated to the terminal through signaling of the base station.

[0508] The SRS resource set or the second SRS resource set may include two or more SRS resources. In codebook-based PUSCH transmission, one SRS resource may be interpreted as corresponding to each Tx panel of the terminal. In non-codebook-based PUSCH transmission, one SRS resource may be interpreted as corresponding to each DM-RS port.

[0509] A common power control parameter set for SRS resources belonging to the same SRS resource set may be indicated to the terminal. A common resource type (e.g., semi-persistent resource, periodic resource, and / or aperiodic resource) for SRS resources belonging to the same SRS resource set may be indicated to the terminal. When the terminal performs STxMP PUSCH transmission, it may be preferable to indicate to the terminal separate power control parameters for each Tx panel of the terminal. Therefore, an SRS resource set may be indicated to each Tx panel of the terminal.

[0510] To support the above operations, even if a UL signal / channel is received at one TRP, two or more SRS resource sets may be indicated to the terminal. These two or more SRS resource sets may be used to transmit overlapping UL signals / channels or SRS in all symbols.

[0511] For convenience of description, the SRS resource sets corresponding to the Tx panels can be referred to as (first) additional SRS resource sets or second additional SRS resource sets. The methods for the first SRS resource set and the first additional SRS resource set or their extensions can be applied to the second SRS resource set and the second additional SRS resource set.

[0512] Figure 24 is a conceptual diagram showing a first exemplary embodiment of an SRS configuration considering a plurality of Tx panels, and Figure 25 is a conceptual diagram illustrating a first exemplary embodiment of an SRS configuration considering multiple TRPs and multiple Tx panels.

[0513] refer to Figure 24 and / or Figure 25 , two SRS resource sets may be associated with PUSCH transmission. The base station may indicate to the terminal codebook-based PUSCH transmission or non-codebook-based PUSCH transmission, and may indicate to the terminal one or two SRS resource sets.

[0514] Considering the UL signal / channel sent to one TRP, the SRS resource set and the additional SRS resource set may be indicated to the terminal. Alternatively, the first SRS resource set and the first additional SRS resource set may be indicated to the terminal. The SRS resource set and the additional SRS resource set may include the same or different numbers of SRS resources.

[0515] Taking into account the codebook-based PUSCH transmission, the SRS resource set and the additional SRS resource set may include the same number of SRS resources. For example, when the Tx panels have the same structure, the array configuration used by the Tx panels with the same structure may be the same. In other words, the base station may indicate the same array configuration for the Tx panel to the terminal through signaling. For example, each Tx panel may support up to 4 ports, and the array configuration may be a two-dimensional array represented as (N1, N2) = (2, 1). Alternatively, each Tx panel may support up to 2 ports, and the array configuration may be a one-dimensional array represented as (N1, N2) = (1, 1). N1 may be the maximum number of ports supported by the first dimension of the array. N2 may be the maximum number of ports supported by the second dimension of the array. In the present disclosure, a port may represent an antenna port.

[0516] Considering non-codebook-based PUSCH transmission, the SRS resource set and the additional SRS resource set can include the same number of SRS resources. For example, when the Tx panels have the same structure, the Tx panels with the same structure can support the same number of antenna ports. Each Tx panel can support up to 2 antenna ports or up to 4 antenna ports.

[0517] Method 11-5: The SRS resource set and the additional SRS resource set may always include the same number of SRS resources.

[0518] Even when the Tx panels have the same structure, the base station can dynamically instruct the terminal to perform STxMP transmission or transmission using a single Tx panel. The base station can indicate n layers or fewer to the terminal and can schedule PUSCH transmission through UL DCI and / or RRC signaling. n can be 4 or 8.

[0519] In the above case, the terminal can receive scheduling information (e.g., resource allocation information) for STxMP SDM PUSCH transmission from the base station. In this case, the n1 layer can correspond to the SRS resource set, and the n2 layer can correspond to the additional SRS resource set. n1 can be maxLayer1 or smaller, n2 can be maxLayer2 or smaller, and the sum of n1 and n2 can be n. The combination of (n1, n2) can belong to the combination allowed by the technical specifications. The SRS resource set may include at least one SRS resource, and the number of antenna ports for the SRS resource set (e.g., SRS resources) may be n1 or more. The additional SRS resource set may include at least one SRS resource, and the number of antenna ports for the additional SRS resource set (e.g., SRS resources) may be n2 or more. If the structure of the Tx panel is the same, the maximum value of n1 and the maximum value of n2 may be the same.

[0520] The terminal may receive scheduling information (e.g., resource allocation information) for PUSCH transmission using a single Tx panel from the base station. In this case, n layers may correspond to an SRS resource set, and no layer may correspond to an additional SRS resource set. n may be less than or equal to maxLayer. n1 may be equal to n. The SRS resource set may include at least one SRS resource, and the number of antenna ports may be n or more.

[0521] An SRS resource set may include at least two SRS resources. An additional SRS resource set may include at least one SRS resource. Therefore, the number of SRS resources included in the SRS resource set may be different from the number of SRS resources included in the additional SRS resource set. For example, the number of SRS resources included in the SRS resource set may be greater than the number of SRS resources included in the additional SRS resource set.

[0522] Method 11-6: The number of SRS resources included in the SRS resource set may be different from the number of SRS resources included in the additional SRS resource set.

[0523] The Tx panels may have different structures. When the connection status of the power amplifiers used for each Tx panel is different, the Tx panels may have different structures. In this case, the number of antenna ports used for the SRS resources belonging to the SRS resource set may be different from the number of antenna ports used for the SRS resources belonging to the additional SRS resource set. When n1 and n2 are the number of layers corresponding to the Tx panel, n1 ≥ n2 may always hold, depending on the combination of (n1, n2).

[0524] Method 11-7: The number of antenna ports used for SRS resources belonging to an SRS resource set may be different from the number of antenna ports used for SRS resources belonging to an additional SRS resource set.

[0525] In STxMP PUSCH transmission, two or more SRS resource sets can be used. Different power control parameter sets can be applied to a group of SRS resources selected from two or more SRS resource sets. For ease of description, the power corresponding to SRS resource 1 belonging to an SRS resource set can be referred to as P1, and the power corresponding to SRS resource 2 belonging to an additional SRS resource set can be referred to as P2. The terminal can transmit PUSCH using a power of (P1 + P2).

[0526] The terminal can derive P1 and P2 based on the method defined in the technical specification. If P1+P2 is not greater than the maximum power (e.g. P CMAX，f，c ), the terminal can use the power of P1+P2 to perform PUSCH transmission. If P1+P2 is greater than the maximum power (for example, P CMAX，f，c ), the power of PUSCH (e.g., transmit power) can be reduced.

[0527] In the proposed method, power reduced at a common reduction ratio can be allocated to a set of SRS resources. The power used for each SRS resource can be reduced from Pi to Pi'. The same reduction ratio (e.g., P1' / P1 = P2' / P2 < 1) can be applied to each SRS resource. The terminal's transmit power can be (P1' + P2'), and (P1' + P2') may not be greater than the maximum power.

[0528] Method 11-8: The power allocated to each SRS resource can be reduced at the same ratio. The terminal can simultaneously perform SRS transmissions in the SRS resources by using the power at the same ratio. The sum of the transmit power used for all SRS transmissions shall not exceed the maximum power.

[0529] The terminal can utilize the Tx panel as follows. For example, the terminal may not use an SRS resource set and may add spatial information of SRS resources belonging to the same SRS resource set. In this case, each Tx panel may be associated with each spatial information.

[0530] For example, in the information about SRS resources, joint / UL TCI or spatial relationship information can be associated with two or more RSs. For example, CSI-RS, SSB, and / or SRS can be associated with joint / UL TCI or spatial relationship information. The first information can be associated with the first Tx panel, and the second information can be associated with the second Tx panel.

[0531] Method 11-9: Two or more pieces of space information allocated to one SRS resource may be indicated or configured, and each piece of space information may be associated with each Tx panel.

[0532] The operation of the method according to the exemplary embodiments of the present disclosure can be implemented as a computer-readable program or code in a computer-readable recording medium. The computer-readable recording medium may include various recording devices for storing data that can be read by a computer system. In addition, the computer-readable recording medium can store and execute programs or codes, which can be distributed among computer systems connected via a network and read by computers in a distributed manner.

[0533] The computer readable recording medium may include a hardware device specifically configured to store and execute program commands, such as ROM, RAM, or flash memory. The program commands may include not only machine language codes generated by a compiler, but also high-level language codes executed by a computer through an interpreter.

[0534] Although some aspects of the present disclosure have been described in the context of a device, these aspects can be indicated according to the corresponding description of the method, and the block or device can correspond to the steps of the method or the features of the steps. Similarly, the aspects described in the context of the method can be expressed as the features of the corresponding blocks or items or corresponding devices. Some or all of the steps of the method can be performed by (or using) hardware devices (such as microprocessors, programmable computers or electronic circuits). In some embodiments, one or more of the most important steps of the method can be performed by such devices.

[0535] In some exemplary embodiments, a programmable logic device (such as a field programmable gate array) can be used to perform some or all of the functions of the methods described herein. In some exemplary embodiments, a field programmable gate array can be used in conjunction with a microprocessor to perform one of the methods described herein. Typically, these methods are preferably performed by specific hardware devices.

[0536] The description of the present disclosure is merely illustrative in nature, and therefore, variations that do not depart from the essence of the present disclosure are intended to be included within the scope of the present disclosure. Such variations should not be regarded as departing from the spirit and scope of the present disclosure. Therefore, it should be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope defined by the appended claims.

Claims

1. A method for a terminal, the method comprising: receiving a first synchronization signal block (SSB) from a first transmit and receive point (TRP); determining a first downlink (DL) timing based on the first SSB; receiving a second SSB from a second TRP; determining a second DL timing based on the second SSB; receiving a physical downlink control channel (PDCCH) command from the first TRP; as well as In response to a first information element included in the PDCCH order indicating the second SSB or the second TRP, a random access (RA) preamble is sent to the second TRP based on the second DL timing.

2. The method according to claim 1, further comprising: Information indicating that the terminal supports two DL timings is sent to at least one of the first TRP or the second TRP.

3. The method according to claim 1, wherein The first DL timing is different from the second DL timing, and a difference between the first DL timing and the second DL timing is equal to or less than a cyclic prefix (CP) or exceeds the CP.

4. The method according to claim 1, wherein A first timing advance (TA) between the terminal and the first TRP is determined based on the first DL timing, and a second TA between the terminal and the second TRP is determined based on the second DL timing.

5. The method according to claim 1, wherein The first information element is information for selecting an SSB index indicating the second SSB or a physical cell identifier (PCI) indicating the second TRP.

6. The method according to claim 1, further comprising: receiving a medium access control (MAC) control element (CE) from the second TRP in response to the RA preamble; as well as deriving at least one of a first TA between the terminal and the first TRP, a second TA between the terminal and the second TRP, or a TA command (TAC) based on an information element included in the MAC CE, The first TA and the second TA belong to different TA groups (TAGs).

7. The method according to claim 6, wherein: When uplink transmission to which the first TA or the second TA is applied is performed, a TAG identifier for determining the first TA or the second TA is derived from spatial relationship information or transmission configuration indication (TCI) referenced by the uplink transmission.

8. The method according to claim 1, wherein The terminal has two or more panels, a first communication between the terminal and the first TRP is performed in a first panel among the two or more panels, and a second communication between the terminal and the second TRP is performed in a second panel among the one or more panels.

9. A method for a base station, the method comprising: transmitting a first synchronization signal block (SSB) via a first transmit and receive point (TRP) associated with the base station; sending a second SSB via a second TRP associated with the base station; Sending a physical downlink control channel (PDCCH) command to the terminal through the first TRP; as well as A random access (RA) preamble is received from the terminal through the second TRP indicated by the PDCCH order.

10. The method according to claim 9, further comprising: Information indicating that the terminal supports two DL timings is received from the terminal through at least one of the first TRP or the second TRP.

11. The method according to claim 9, wherein: A first DL timing is determined at the terminal based on the first SSB, a second DL timing is determined at the terminal based on the second SSB, the first DL timing is different from the second DL timing, and a difference between the first DL timing and the second DL timing is equal to or less than a cyclic prefix (CP) or exceeds the CP.

12. The method according to claim 11, wherein A first timing advance (TA) between the terminal and the first TRP is determined based on the first DL timing, and a second TA between the terminal and the second TRP is determined based on the second DL timing.

13. The method according to claim 9, wherein: The PDCCH command includes a first information element, and the first information element is information for selecting an SSB index indicating the second SSB or a physical cell identifier (PCI) indicating the second TRP.

14. The method according to claim 9, further comprising: In response to the RA preamble code, a medium access control (MAC) control element (CE) is sent through the second TRP, wherein the information elements included in the MAC CE are used to derive at least one of a first TA between the terminal and the first TRP, a second TA between the terminal and the second TRP, or a TA command (TAC), and the first TA and the second TA belong to different TA groups (TAGs).

15. The method according to claim 14, wherein When uplink transmission to which the first TA or the second TA is applied is performed, a TAG identifier for determining the first TA or the second TA is derived from spatial relationship information or transmission configuration indication (TCI) referenced by the uplink transmission.

16. A terminal comprising at least one processor, wherein: The at least one processor causes the terminal to execute: receiving a first synchronization signal block (SSB) from a first transmit and receive point (TRP); determining a first downlink (DL) timing based on the first SSB; receiving a second SSB from a second TRP; determining a second DL timing based on the second SSB; receiving a physical downlink control channel (PDCCH) command from the first TRP; as well as In response to a first information element included in the PDCCH order indicating the second SSB or the second TRP, a random access (RA) preamble is sent to the second TRP based on the second DL timing. The terminal according to claim 16 , wherein: The at least one processor further causes the terminal to execute: sending information indicating that the terminal supports two DL timings to at least one of the first TRP or the second TRP. The terminal according to claim 16 , wherein: The first DL timing is different from the second DL timing, and a difference between the first DL timing and the second DL timing is equal to or less than a cyclic prefix (CP) or exceeds the CP. The terminal according to claim 16 , wherein: The first information element is information for selecting an SSB index indicating the second SSB or a physical cell identifier (PCI) indicating the second TRP.

20. The terminal according to claim 16, wherein: The at least one processor further causes the terminal to execute: receiving a medium access control (MAC) control element (CE) from the second TRP in response to the RA preamble; and deriving at least one of a first TA between the terminal and the first TRP, a second TA between the terminal and the second TRP, or a TA command (TAC) based on an information element included in the MAC CE, The first TA and the second TA belong to different TA groups (TAGs).

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