Method and apparatus for managing radio link in communication system

Abstract

A method and an apparatus for managing a radio link in a communication system are disclosed. The method of a terminal comprises the steps of: transmitting a first uplink reference signal (UL RS) to one or more transmission and reception points (TRPs); transmitting a second UL RS to the one or more TRPs after a preset time from the transmission time point of the first UL RS; and receiving, from the one or more TRPs, a downlink (DL) channel compensated on the basis of the first UL RS and the second UL RS.

Description

Method and device for wireless link management in a communication system

[0001] The present disclosure relates to communication technology, and more particularly, to management technology of a wireless link.

[0002] To handle the rapidly increasing wireless data, communication systems (e.g., new radio (NR) communication systems) that use higher frequency bands (e.g., frequency bands higher than 6 GHz) than those of long term evolution (LTE) (or LTE-A) (e.g., frequency bands lower than 6 GHz) are being considered. NR communication systems can support frequency bands higher than 6 GHz as well as lower than 6 GHz, and can support a wider variety of communication services and scenarios compared to LTE communication systems. For example, usage scenarios of NR communication systems may include enhanced Mobile Broadband (eMBB), Ultra Reliable Low Latency Communication (URLLC), massive Machine Type Communication (mMTC), etc. Communication technologies that can satisfy the requirements of eMBB, URLLC, and mMTC are needed.

[0003] Meanwhile, with the advancement of information and communication technology, various wireless communication technologies are being developed. Wireless communication technologies may include LTE communication technology and NR communication technology, which are stipulated in the 3rd generation partnership project (3GPP) standards. LTE communication technology may be one of the 4th Generation (4G) wireless communication technologies, and NR communication technology may be one of the 5th Generation (5G) wireless communication technologies. In order to process the rapid increase in wireless data after the commercialization of 4G communication systems (e.g., communication systems supporting LTE communication technology), 5G communication systems (e.g., communication systems supporting NR communication technology) that use higher frequency bands (e.g., frequency bands higher than 6 GHz) than the frequency bands of 4G communication systems are being considered. 5G communication systems may support eMBB, URLLC, mMTC, and / or TSC (time sensitive communication). In particular, mMTC, URLLC, and / or TSC can be applied in Internet of Things (IoT) scenarios. A single communication network (e.g., a single communication system) can support all or some of the above scenarios. The mMTC scenario can satisfy the International Mobile Telecommunication (IMT)-2020 requirements using narrowband (NB)-IoT and LTE-MTC. Development of technologies to satisfy the requirements of the URLLC scenario is necessary.

[0004] The purpose of the present disclosure to solve the above problems is to provide a method and device for wireless link management in a communication system.

[0005] According to embodiments of the present disclosure for achieving the above object, a method of a terminal includes the steps of: transmitting a first UL RS (uplink reference signal) to one or more TRPs (transmission and reception points); transmitting a second UL RS to the one or more TRPs after a preset time from a transmission time of the first UL RS; and receiving a compensated DL (downlink) channel based on the first UL RS and the second UL RS from the one or more TRPs, wherein consistency of transmission of the first UL RS and the second UL RS is maintained.

[0006] The method of the terminal may further include the step of receiving a message requesting multiple UL RS transmissions from at least one TRP among the one or more TRPs, and transmissions for the first UL RS and the second UL RS may be performed based on the request.

[0007] The DL channel may be compensated based on a first difference between the first UL RS and the second UL RS received in a first TRP among the one or more TRPs and a second difference between the first UL RS and the second UL RS received in a second TRP among the one or more TRPs.

[0008] Each of the first difference and the second difference may be a time difference according to a time interval between transmission of the first UL RS and transmission of the second UL RS, and the time difference may correspond to a phase difference.

[0009] Each of the first difference and the second difference may be a power difference between the power of the first UL RS and the power of the second UL RS, and the power difference may correspond to a phase difference.

[0010] The above DL channel may be a DL channel in which at least one of a time offset, a frequency offset, or a phase offset is compensated.

[0011] The above consistency may include at least one of the same TA (timing advance) or the same transmit power.

[0012] Phase continuity for transmission of the first UL RS and the second UL RS can be maintained.

[0013] According to embodiments of the present disclosure for achieving the above object, a method of a first TRP includes the steps of: receiving a first UL RS from a terminal; receiving a second UL RS from the terminal after a preset time from the time of receiving the first UL RS; compensating a DL channel based on the first UL RS and the second UL RS; and transmitting the DL channel to the terminal, wherein consistency in transmission of the first UL RS and the second UL RS is maintained.

[0014] The method of the first TRP may further include a step of transmitting a message requesting multiple UL RS transmissions to the terminal, and transmissions for the first UL RS and the second UL RS may be performed based on the request.

[0015] The step of compensating the DL channel may include: a step of deriving a first difference between the first UL RS and the second UL RS; a step of receiving information on a second difference between the first UL RS and the second UL RS received in the second TRP from the second TRP; and a step of compensating the DL channel based on the first difference and the second difference.

[0016] Each of the first difference and the second difference may be a time difference according to a time interval between the first UL RS and the second UL RS, and the time difference may correspond to a phase difference.

[0017] Each of the first difference and the second difference may be a power difference between the first UL RS and the second UL RS, and the power difference may correspond to a phase difference.

[0018] The above consistency may include at least one of the same TA or the same transmit power.

[0019] Phase continuity for transmission of the first UL RS and the second UL RS can be maintained.

[0020] According to embodiments of the present disclosure for achieving the above object, a terminal includes at least one processor, wherein the at least one processor causes the terminal to transmit a first UL RS to one or more TRPs; transmit a second UL RS to the one or more TRPs after a preset time from a transmission time of the first UL RS; and receive a compensated DL channel based on the first UL RS and the second UL RS from the one or more TRPs, wherein consistency of transmission of the first UL RS and the second UL RS is maintained.

[0021] The at least one processor may further cause the terminal to receive a message requesting multiple UL RS transmissions from at least one TRP among the one or more TRPs, and transmissions for the first UL RS and the second UL RS may be performed based on the request.

[0022] The DL channel may be compensated based on a first difference between the first UL RS and the second UL RS received in a first TRP among the one or more TRPs and a second difference between the first UL RS and the second UL RS received in a second TRP among the one or more TRPs.

[0023] Each of the first difference and the second difference may be a time difference according to a time interval between transmission of the first UL RS and transmission of the second UL RS, and the time difference may correspond to a phase difference.

[0024] Each of the first difference and the second difference may be a power difference between the power of the first UL RS and the power of the second UL RS, and the power difference may correspond to a phase difference.

[0025] According to the present disclosure, a terminal can transmit a plurality of uplink references (UL RSs) to a plurality of transmission and reception points (TRPs). The plurality of TRPs can compensate for a downlink (DL) channel based on the plurality of UL RSs received from the terminal and transmit the DL channel to the terminal. The terminal can receive the DL channel from the plurality of TRPs. Since the DL channel has been previously compensated for by the plurality of TRPs, the compensation procedure for the DL channel at the terminal can be omitted or simplified. Therefore, the efficiency of DL communication can be improved, and the performance of the communication system can be enhanced.

[0026] Figure 1 is a conceptual diagram illustrating embodiments of a communication system.

[0027] Figure 2 is a block diagram illustrating an embodiment of a communication node constituting a communication system.

[0028] Figure 3 is a flowchart illustrating a first embodiment of a communication method between a terminal and a TRP.

[0029] Figure 4 is a conceptual diagram illustrating a first embodiment of SRS resources.

[0030] Figure 5 is a conceptual diagram illustrating a second embodiment of SRS resources.

[0031] Figure 6 is a conceptual diagram illustrating a third embodiment of SRS resources.

[0032] Figure 7 is a conceptual diagram illustrating a first embodiment of TRS resources.

[0033] Figure 8 is a conceptual diagram illustrating a first embodiment of an SRS transmission method.

[0034] Figure 9 is a conceptual diagram illustrating a second embodiment of an SRS transmission method.

[0035] Figure 10 is a conceptual diagram illustrating a third embodiment of an SRS transmission method.

[0036] Figure 11 is a conceptual diagram illustrating a fourth embodiment of an SRS transmission method.

[0037] Figure 12 is a flowchart illustrating a second embodiment of a communication method between a terminal and a TRP.

[0038] This disclosure may be subject to various modifications and various embodiments. Specific embodiments are illustrated and described in detail in the drawings. However, this is not intended to limit the disclosure to specific embodiments, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the disclosure.

[0039] While terms such as "first" and "second" may be used to describe various components, these components should not be limited by these terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of the present disclosure, a first component could be referred to as a "second component," and similarly, a second component could also be referred to as a "first component." The term "and / or" encompasses any combination of multiple related items or any one of multiple related items.

[0040] In embodiments of the present disclosure, “at least one of A and B” may mean “at least one of A or B” or “at least one of combinations of one or more of A and B.” Furthermore, in embodiments of the present disclosure, “at least one of A and B” may mean “at least one of A or B” or “at least one of combinations of one or more of A and B.”

[0041] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

[0042] The terminology used in this disclosure is only used to describe specific embodiments and is not intended to limit the present disclosure. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this disclosure, it should be understood that the terms "comprises" or "has" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0043] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which this disclosure pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0044] Hereinafter, preferred embodiments of the present disclosure will be described in more detail with reference to the attached drawings. In order to facilitate an overall understanding in describing the present disclosure, identical reference numerals will be used for identical components in the drawings, and redundant descriptions of identical components will be omitted.

[0045] A communication system to which embodiments according to the present disclosure are applied will be described. The communication system to which embodiments according to the present disclosure are applied is not limited to the scope described below, and embodiments according to the present disclosure can be applied to various communication systems. Here, the term "communication system" may be used interchangeably with "communication network."

[0046] In an embodiment, "an operation (e.g., a transmission operation) is set" may mean that "setting information for the operation (e.g., an information element, a parameter)" and / or "information instructing performance of the operation" are signaled. "An information element (e.g., a parameter) is set" may mean that the information element is signaled. The signaling may be at least one of system information (SI) signaling (e.g., transmission of a master information block (MIB), a system information block (SIB), and / or an SI message), radio resource control (RRC) signaling (e.g., transmission of an RRC message, an RRC parameter, and / or an upper layer parameter), MAC control element (CE) signaling (e.g., transmission of a MAC message and / or a MAC CE), or PHY signaling (e.g., transmission of downlink control information (DCI), uplink control information (UCI), and / or sidelink control information (SCI)).

[0047] Figure 1 is a conceptual diagram illustrating embodiments of a communication system.

[0048] Referring to FIG. 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, 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), a mobility management entity (MME)). If the communication system (100) is a 5G communication system (e.g., a new radio (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.

[0049] A plurality of communication nodes (110 to 130) can support a communication protocol (e.g., LTE communication protocol, LTE-A communication protocol, NR communication protocol, etc.) specified in the 3GPP (3rd generation partnership project) standard. The plurality of communication nodes (110 to 130) may support CDMA (code division multiple access) technology, WCDMA (wideband CDMA) technology, TDMA (time division multiple access) technology, FDMA (frequency division multiple access) technology, OFDM (orthogonal frequency division multiplexing) technology, Filtered OFDM technology, CP (cyclic prefix)-OFDM technology, DFT-s-OFDM (discrete Fourier transform-spread-OFDM) technology, OFDMA (orthogonal frequency division multiple access) technology, SC (single carrier)-FDMA technology, NOMA (non-orthogonal multiple access) technology, GFDM (generalized frequency division multiplexing) technology, FBMC (filter bank multi-carrier) technology, UFMC (universal filtered multi-carrier) technology, SDMA (space division multiple access) technology, etc. Each of the plurality of communication nodes may have the following structure.

[0050] Figure 2 is a block diagram illustrating embodiments of communication nodes constituting a communication system.

[0051] Referring to FIG. 2, a communication node (200) may include at least one processor (210), a memory (220), and a transmission / reception device (230) that is connected to a network and performs 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. Each component included in the communication node (200) may be connected by a bus (270) and communicate with each other.

[0052] However, each component included in the communication node (200) may be connected through an individual interface or individual bus centered around the processor (210), rather than a common bus (270). For example, the processor (210) may be connected to at least one of a memory (220), a transmission / reception device (230), an input interface device (240), an output interface device (250), and a storage device (260) through a dedicated interface.

[0053] The processor (210) can execute program commands 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 in which the methods according to embodiments of the present disclosure are performed. Each of the memory (220) and the storage device (260) may be configured with at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory (220) may be configured with at least one of a read-only memory (ROM) and a random access memory (RAM).

[0054] Referring again to FIG. 1, the communication system (100) may include a plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) and a plurality of terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6). Each of the first base station (110-1), the second base station (110-2), and the third base station (110-3) may form a macro cell. Each of the fourth base station (120-1) and the fifth base station (120-2) may form a small cell. The fourth base station (120-1), the third terminal (130-3), and the fourth terminal (130-4) may be within the cell coverage of the first base station (110-1). The second terminal (130-2), the fourth terminal (130-4), and the fifth terminal (130-5) may be within the cell coverage of the second base station (110-2). The fifth base station (120-2), the fourth terminal (130-4), the fifth terminal (130-5), and the sixth terminal (130-6) may be within the cell coverage of the third base station (110-3). The first terminal (130-1) may be within the cell coverage of the fourth base station (120-1). The sixth terminal (130-6) may be within the cell coverage of the fifth base station (120-2).

[0055] Here, each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may be referred to as a NodeB (NB), an evolved NodeB (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 multihop 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.

[0056] Each of the plurality of terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) may be referred to as a user equipment (UE), terminal equipment (TE), advanced mobile station (AMS), high reliability-mobile station (HR-MS), terminal, access terminal, mobile terminal, station, subscriber station, mobile station, portable subscriber station, node, device, on board unit (OBU), etc.

[0057] Meanwhile, each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may operate in a different frequency band or may operate in the same frequency band. Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may be connected to each other via an ideal backhaul link or a non-ideal backhaul link, and may exchange information with each other via the ideal backhaul link or the non-ideal backhaul link. Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may be connected to the core network via the ideal backhaul link or the non-ideal backhaul link. Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) can transmit a signal received from the core network to the corresponding terminal (130-1, 130-2, 130-3, 130-4, 130-5, 130-6), and can transmit a signal received from the corresponding terminal (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) to the core network.

[0058] Additionally, each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may support multi-input multi-output (MIMO) transmission (e.g., single user (SU)-MIMO, multi user (MU)-MIMO, massive MIMO, etc.), coordinated multipoint (CoMP) transmission, carrier aggregation (CA) transmission, transmission in an unlicensed band, device to device communication (D2D) (or, proximity services (ProSe)), Internet of Things (IoT) communication, dual connectivity (DC), etc. Here, each of the plurality of terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) can perform an operation corresponding to the base station (110-1, 110-2, 110-3, 120-1, 120-2) and an operation supported by the base station (110-1, 110-2, 110-3, 120-1, 120-2). For example, the second base station (110-2) can transmit a signal to the fourth terminal (130-4) based on the SU-MIMO scheme, and the fourth terminal (130-4) can receive a signal from the second base station (110-2) by the SU-MIMO scheme. Alternatively, the second base station (110-2) can transmit signals to the fourth terminal (130-4) and the fifth terminal (130-5) based on the MU-MIMO method, and each of the fourth terminal (130-4) and the fifth terminal (130-5) can receive signals from the second base station (110-2) based on the MU-MIMO method.

[0059] Each of the first base station (110-1), the second base station (110-2), and the third base station (110-3) can transmit a signal to the fourth terminal (130-4) based on the CoMP scheme, and the fourth terminal (130-4) can receive a signal from the first base station (110-1), the second base station (110-2), and the third base station (110-3) based on the CoMP scheme. Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) can transmit and receive a signal with terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) within its cell coverage based on the CA scheme. Each of the first base station (110-1), the second base station (110-2), and the third base station (110-3) can control D2D between the fourth terminal (130-4) and the fifth terminal (130-5), and each of the fourth terminal (130-4) and the fifth terminal (130-5) can perform D2D under the control of the second base station (110-2) and the third base station (110-3).

[0060] Next, the operating methods of communication nodes in a communication system will be described. Even if a method (e.g., signal transmission or reception) performed by a first communication node among communication nodes is described, a corresponding second communication node can perform a method (e.g., signal reception or transmission) corresponding to the method performed by the first communication node. In other words, if the operation of a terminal is described, the corresponding base station can perform an operation corresponding to the operation of the terminal. Conversely, if the operation of a base station is described, the corresponding terminal can perform an operation corresponding to the operation of the base station. In the present disclosure, the operation of a TRP can be interpreted as an operation performed by a base station, and the operation of the base station can be interpreted as an operation performed by a TRP.

[0061] A communication system can support various wireless communication technologies. These technologies may include long-term evolution (LTE) and new radio (NR) technologies, as defined by the 3rd generation partnership project (3GPP) standards. LTE may be one of the 4th generation (4G) wireless communication technologies. NR may be one of the 5th generation (5G) wireless communication technologies.

[0062] In order to process the rapidly increasing amount of wireless data following the commercialization of 4G communication systems (e.g., communication systems supporting LTE communication technology), 5G communication systems (e.g., communication systems supporting NR communication technology) that use a higher frequency band (e.g., a frequency band higher than 6 GHz) than the frequency band of the 4G communication system as well as the frequency band of the 4G communication system are being considered. The 5G communication system may support enhanced Mobile BroadBand (eMBB), Ultra Reliable Low Latency Communication (URLLC), massive Machine Type Communication (mMTC), and / or time sensitive communication (TSC). In particular, mMTC, URLLC, and / or TSC may be applied in 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 International Mobile Telecommunication (IMT)-2020 requirements by utilizing narrowband (NB)-IoT and LTE-MTC. Technology development is needed to meet the requirements of the URLLC scenario.

[0063] To reduce data error rates, a lower modulation and coding scheme (MCS) level (e.g., a lower MCS index) can be applied. To prevent the size of the field indicated by the downlink control information (DCI) (e.g., the information field) from increasing, the most frequently used MCS(s) can be selected. Subsequently, to apply a lower MCS, a repetitive transmission operation can be supported. Since quadrature phase shift keying (QPSK) has the lowest modulation rate, this can have the effect of further reducing the code rate. In particular, since the transmit power in uplink (UL) transmission is limited, the repetitive transmission operation can be performed in the time domain rather than the frequency domain.

[0064] eMBB (enhanced Mobile Broadband) traffic and URLLC (Ultra-Reliable and Low Latency Communication) traffic can use low MCS for different purposes. eMBB traffic can use low MCS to extend the reach. On the other hand, URLLC traffic can use low MCS to reduce latency and achieve low error rates. Because of their different requirements, eMBB traffic can be transmitted repeatedly even if latency occurs, while URLLC traffic can be transmitted using a new MCS (e.g., a lower MCS) rather than repeated transmissions. The new MCS can be set by an RRC message and / or DCI.

[0065] To support repetitive transmissions for eMBB traffic in the time domain, physical uplink shared channel (PUSCH) repetition (e.g., PUSCH repetition type A) may be introduced. In this case, PUSCH allocated in slot units may be repeatedly transmitted. To extend the reach, time resources may be allocated to multiple slots. When PUSCH repetition type A is used, the time resources may be configured by an RRC message and / or a DCI. The number of repetitions of the PUSCH may be indicated by the RRC message, and the time resource in which the PUSCH is transmitted in the first slot may be indicated by a DCI (e.g., a type 2 CG (configured grant) or a dynamic grant) or an RRC message (e.g., a type 1 CG). In the present disclosure, the number of repetitions may mean the number of repeated transmissions or the number of transmissions.

[0066] Repeated transmission of URLLC traffic may not be appropriate because it incurs delay when the traffic is repeatedly transmitted. However, if a sufficiently low MCS is used, the delay for decoding URLLC traffic can be reduced. That is, if a sufficiently low MCS is used, the number of REs (resource elements) to which URLLC traffic is mapped may increase, and the base station (e.g., the base station decoder) must wait until all REs are received. In this case, the delay for decoding URLLC traffic can be reduced.

[0067] On the other hand, if a PUSCH with a relatively high MCS is repeatedly transmitted, the base station can perform a decoding operation using only some REs. Therefore, the time point of first successful decoding in a PUSCH repeated transmission (e.g., a PUSCH repeated transmission with a relatively high MCS) may be earlier than the time point of first successful decoding in a PUSCH transmission without repetition (e.g., a PUSCH transmission with a low MCS). If PUSCH repetition type A is used, unnecessary delay may occur, and PUSCH repetition type B may be introduced to reduce the delay time for repeated transmission. If PUSCH repetition type B is used, a PUSCH allocated in units of mini-slots may be repeatedly transmitted. If PUSCH repetition type B is used, the time resource may be set by an RRC message and / or DCI. The combination of the reference time resource and the number of repeated transmissions of a PUSCH instance can be indicated by a DCI (e.g., Type 2 CG and / or dynamic grant) or an RRC message (e.g., Type 1 CG).

[0068] In order to control the transmit power of SRS resources indicated by SRI (SRS (sounding reference signal) resource indicator), the base station can estimate the path attenuation for each SRS resource. The base station can control the transmit power for the SRS resource(s) using DCI. The transmit power of the SRS resource(s) can be controlled based on the estimated path attenuation. The DCI can be 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 GC (group common)-DCI (e.g., DCI format 2_2 or DCI format 2_3). The DCI can include a field indicating a transmit power control (TPC) command, and the TPC command can be used to control the transmit power of a terminal. For example, the transmission power of a terminal may be increased or decreased based on a TPC command included in the DCI. To determine the transmission power of a PUSCH, the terminal may consider a value obtained based on path attenuation, a value according to a TPC command included in the DCI, and / or a PUSCH bandwidth indicated by the DCI.

[0069] A base station can configure two or more sets for a terminal using higher layer signaling. The terminal can receive configuration information for the two or more sets from the base station. Each element constituting the two or more sets can be a transmit power parameter(s), which can be designated to suit different scenarios (e.g., a URLLC scenario, an eMBB scenario). The terminal can receive a scheduling DCI or an activating DCI from the base station that allocates PUSCH resources, and the scheduling DCI or the activating DCI can indicate a set for interpreting the transmit power parameter(s). If the sets of transmit power parameter(s) are different, the magnitude of the increase or decrease in transmit power designated by the same TPC command can be different.

[0070] When Type 1 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 Type 2 CG is used, the activation DCI may indicate a set of transmit power parameter(s) applicable to a PUSCH occasion. A PUSCH occasion may mean a PUSCH instance. The UE may obtain a TPC command for the SRI by receiving a GC (group common)-DCI, interpret the TPC command to be suitable for the set of transmit power parameter(s) indicated by the base station, and derive the transmit power applicable to the PUSCH instance based on the interpretation result.

[0071] In a dynamically scheduled PUSCH transmission, the UE can derive the transmit power applied to the PUSCH instance based on a combination of GC-DCI and scheduling DCI. The UE can identify the TPC command of the SRI by receiving the GC-DCI and store the identified TPC command. In a dynamically scheduled PUSCH transmission, a set of transmit power parameter(s) and / or TPC command applied to the PUSCH occasion can be indicated by scheduling DCI. The UE can derive the transmit power applied to the PUSCH instance based on the transmit power of the SRI associated with the PUSCH instance.

[0072] Repeated HARQ-ACK transmission can be indicated (or configured) by higher-layer signaling for each PUCCH (physical uplink control channel) format (or PUCCH resource). The number of repeated transmissions for PUCCH format i can be configured independently. i can be 1, 3, or 4. The UE can repeatedly transmit the PUCCH format (or PUCCH resource) in slots. In this case, the PUCCH format (or PUCCH resource) can be transmitted using the same time resource in each slot.

[0073] Uplink control information (UCI) types can be classified according to the type of information included in the UCI. UCI can include at least one of scheduling request (SR), L1-RSRP (reference signal received power), HARQ-ACK, or channel state information (CSI). In embodiments, UCI and UCI type can be used interchangeably. In a repeated transmission operation of UCI, only one UCI type can be transmitted. To support this operation, the priority of UCI types can be defined in the technical specification. One UCI type can be selected, and a PUCCH including one UCI type can be repeatedly transmitted. In this case, the terminal can assume that no other UCI types are transmitted before the transmission of the corresponding UCI type is completed. To support this operation, the base station can instruct the terminal to transmit UCI (e.g., SR or HARQ-ACK) after the PUCCH transmission is completed. The latency for the UCI transmission may be high, and this latency may act as a scheduling constraint for the base station.

[0074] When "transmission of HARQ-ACKs in the same slot (or the same sub-slot)" or "PUCCH time resources indicated by DCI and / or RRC message allocating PDSCH (physical downlink shared channel) overlap each other," the terminal may generate a HARQ codebook to be transmitted in one PUCCH (e.g., one PUCCH time resource). Within the HARQ codebook, HARQ-ACK bits may be arranged according to an order defined in the technical specification. Information bits may be generated by the above-described operation. The terminal may generate coded bits by performing an coding operation.

[0075] Reed-Muller codes or polar codes can be used in encoding operations. The code rate applied in encoding operations can be indicated by higher-layer signaling. For example, in the PUCCH format, a single value can be the code rate and can be indicated to the terminal.

[0076] One codeword can be mapped to one PUCCH. In a PUCCH repeated transmission operation, one UCI type can be generated as a codeword. When a PUCCH is transmitted once, information bits of one UCI type or two or more UCI types can be concatenated, and the terminal can generate one codeword by performing the same encoding operation on the information bits. When a Reed-Muller code or a polar code is used, performing a soft combining operation may be difficult in implementation. Therefore, even when a PUCCH is repeatedly transmitted, the same codeword can be transmitted, and the base station can perform a chase combining operation on the same codeword. The encoded bits or codeword can mean 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 an RE.

[0077] Meanwhile, identical UCI types may be considered different information. Identical UCI types considered different information can be mapped. For example, UCIs may be created to support traffic with different priorities. UCIs supporting eMBB traffic (e.g., SR or HARQ-ACK) may be considered distinct information from UCIs supporting URLLC traffic (e.g., SR or HARQ-ACK). In this case, even if UCI types are identical, they may be distinguished as different information.

[0078] Encoded UCI can be mapped to PUCCH. The same preprocessing scheme (e.g., spatial information, spatial relation) can be maintained in PUCCH transmission operations. Alternatively, in PUCCH transmission operations, the use of different preprocessing schemes for each PUCCH can be permitted through base station signaling (e.g., RRC signaling).

[0079] To support URLLC traffic, it may be desirable for a terminal to perform frequent reception operations on downlink (DL) resources and / or frequent transmission operations on uplink (UL) resources. In a time division duplex (TDD) system, a terminal may operate based on a half-duplex scheme. Therefore, the support time for DL ​​traffic and / or UL traffic may increase depending on the slot pattern. On the other hand, in a frequency division duplex (FDD) system, a terminal can utilize DL resources and UL resources. Therefore, the above-described problem in a TDD system may not occur in an FDD system. An FDD system can use two or more carriers. If two or more serving cells are configured for a terminal in a TDD system, the terminal can utilize DL resources and UL resources.

[0080] In a communication system including at least one carrier to which FDD is applied (hereinafter referred to as an "FDD carrier"), there may be no problem with the delay time of the terminal. In a communication system including only carrier(s) to which TDD is applied (hereinafter referred to as "TDD carrier(s)"), there may be a problem with the delay time of the terminal. To solve the above problem, slots in TDD carriers may be configured according to different patterns.

[0081] Transmission of eMBB traffic and / or URLLC traffic may be supported in at least one of a licensed band or an unlicensed band. Carrier(s) in the licensed band may be used solely. Carrier(s) in the unlicensed band may be used solely. Alternatively, depending on the base station configuration, carrier(s) in the licensed band and carrier(s) in the unlicensed band may both be used based on a carrier aggregation scheme.

[0082] In an embodiment, two or more terminals may receive data from one or more TRPs and transmit data to one or more TRPs. It may be assumed that one base station or one server performs management operations and / or scheduling operations for one or more TRPs among the plurality of TRPs. The TRPs may be directly connected. Alternatively, the TRPs may be connected via a base station. The above-described connection may be a connection according to an Xn interface or a wireless interface (e.g., an interface of 3GPP NR).

[0083] Shadow regions can occur between the areas supported by TRPs. Therefore, TRPs can resolve shadow regions through cooperative transmission. Cooperative transmission can be performed on terminals located between TRPs. Even if shadow regions do not occur, wireless link quality can be improved by installing numerous TRPs (or base stations) to transmit and receive large amounts of data.

[0084] Depending on the cooperative transmission and reception of TRPs, communication methods can be classified into dynamic point selection (DPS) and joint transmission (JT). For a specific set of physical resource blocks (PRBs), DPS may be a method of receiving data through a single TRP, and JT may be a method of receiving data through two or more TRPs. Dynamic point blanking (DPB) may be a type of JT. When DPB is used, the terminal may not receive data from some TRPs and may receive data from the remaining TRPs. JT can be classified into coherent JP and noncoherent JP. Depending on whether a coherent combining operation is performed on signals received from TRPs, either coherent JP or noncoherent JP may be used.

[0085] Depending on the latency and / or traffic capacity of the backhaul to which the base station or TRPs are connected, the TRPs may participate in real-time cooperative transmission and / or cooperative reception. Alternatively, depending on the latency and / or traffic capacity of the backhaul to which the base station or TRPs are connected, the TRPs may not participate in real-time cooperative transmission and / or cooperative reception. The TRPs may be connected (e.g., associated) to the same base station or to different base stations. A terminal may support JT by receiving a single DCI (sDCI) or multiple DCIs (mDCI).

[0086] When sDCI is used, a terminal can transmit and receive data with TRPs. TRPs can collaborate without delay through backhaul. When mDCI is used, a terminal can transmit and receive data with some TRPs and other TRPs. However, if real-time collaboration between TRPs via backhaul is difficult, the terminal can use semi-fixed resources (e.g., divided semi-fixed resources) to perform communication.

[0087] To distinguish TRPs, a CORESET (control resource set) pool index can be introduced. The CORESET pool index can indicate a set of CORESETs. The TCI (transmission configuration indication) state of each CORESET can be independently indicated to the UE through signaling (e.g., RRC signaling and / or MAC CE signaling). The CORESET pool index may not necessarily correspond to a TRP. A TRP can be divided into a TxP (transmission point) and an RxP (reception point), and the CORESET pool index can correspond to an RxP. For example, the Rx beam of a UE receiving a DL signal / channel from a TxP can be derived from the TCI state, and UL signals / channels scheduled by DCIs discovered in a CORESET belonging to a CORESET pool corresponding to a single CORESET pool index can be interpreted as being received from the same RxP. In the present disclosure, a DL signal / channel may mean a DL signal and / or a DL channel, and a UL signal / channel may mean a UL signal and / or a UL channel.

[0088] Performance gains can be achieved by performing coherent combining operations at the terminal, provided that TRPs are synchronized and CSI reports are shared. If the above conditions are not met, performing noncoherent combining operations at the terminal may be advantageous in terms of performance.

[0089] If the terminal is mounted on a vehicle, there may be fewer restrictions on its size and / or weight. Portability may be considered for terminals intended for direct human use.

[0090] To expand the coverage area, small cells or IAB nodes can be deployed in a communication system. The transmission capacity of small cells or IAB nodes can be affected by the quality of the backhaul. Securing a high-quality backhaul (e.g., high-quality backhaul) can be costly. As an alternative to this problem, a wireless relay device can be deployed in the communication system, and high-quality signals can be transmitted to terminals through the wireless relay device. Wireless relay devices can be classified into several types depending on the method of signal transmission. A wireless relay device supporting many functions can provide performance similar to that of a base station. If a wireless relay device supporting a small number of functions is deployed, a communication system including the wireless relay device can be constructed at a lower cost. In the present disclosure, the wireless relay device can support a beamforming function for terminals and a minimum number of functions for data transmission. The base station can transmit a signal / channel to control the wireless relay device. A wireless relay device can receive a signal / channel (e.g., a control signal / control channel) from a base station and set appropriate parameter(s) based on the received signal / channel. In other words, the base station can set appropriate parameter(s) in the wireless relay device to control the wireless relay device.

[0091] Figure 3 is a flowchart illustrating a first embodiment of a communication method between a terminal and a TRP.

[0092] Referring to FIG. 3, when a terminal has mobility, it may be desirable for a base station and / or a TRP to track the terminal (e.g., the terminal having mobility). The terminal may perform a timing control operation (e.g., a timing advance (TA) control operation) and / or a power control operation with a serving TRP (e.g., TRP 0) using a physical random access channel (PRACH). In S301, a terminal in an RRC connected state may transmit an SRS to TRP 0, and TRP 0 may receive the SRS from the terminal. In S302, TRP 0 may perform a synchronization compensation operation for time, frequency, and / or phase based on the SRS. For example, TRP 0 can perform a compensation and / or cancellation operation for a time offset based on the SRS, TRP 0 can perform a compensation and / or cancellation operation for a frequency offset based on the SRS, and TRP 0 can perform a compensation and / or cancellation operation for a phase offset based on the SRS.

[0093] TRP 0 can perform scheduling for uplink transmission and / or downlink transmission based on a synchronization compensation operation for time, frequency, and / or phase (e.g., a result of the synchronization compensation operation). For example, TRP 0 can dynamically adjust an MCS for PUSCH transmission. TRP 0 can utilize the result of the synchronization compensation operation for time, frequency, and / or phase as additional information for cooperative transmission with other TRP(s). TRP 0 can transmit scheduling information for uplink transmission (e.g., DCI including scheduling information) to a terminal. The terminal can receive the scheduling information (e.g., DCI) from TRP 0. In S303, the terminal can transmit uplink transmission (e.g., PUSCH transmission and / or PUCCH transmission) to TRP 0 based on the scheduling information, and TRP 0 can receive the uplink transmission from the terminal.

[0094] TRP 0 can be connected to TRP 1 via a backhaul (e.g., Xn interface or F1 interface). If the base station and / or TRPs do not have an ideal backhaul, the latency and / or capacity of the backhaul (e.g., Xn interface or F1 interface) may be considered. The capacity may be the maximum amount of data that can be transmitted per unit time of the TRP. Since all data can be transmitted if a large delay is allowed, only the latency may be considered. To perform joint processing and / or joint scheduling, TRPs may exchange necessary information in advance considering the delay. TRPs may perform joint transmission in predefined resources (e.g., time and / or frequency resources). The UE may receive configuration information of an uplink (UL) RS (e.g., SRS) from a serving TRP and / or a serving cell. In other words, the configuration information of the UL RS may be configured (e.g., instructed) to the UE. Terminals can transmit UL RSs based on their configuration. TRPs can receive UL RSs from the terminals and derive necessary metrics based on the UL RSs. TRPs can transmit the metrics via backhaul (e.g., Xn interface or F1 interface). TRPs can utilize the metrics to perform joint transmission.

[0095] A terminal can transmit an UL transmission to a base station and / or a TRP based on an SRS. In the embodiment of FIG. 3, the terminal can transmit an UL signal / channel (e.g., an UL signal and / or an UL channel) to a serving TRP (e.g., TRP 0). The terminal can roughly perform link management using the SRS. The base station (e.g., TRP) can control the transmission power of the terminal considering the SRS quality. The base station (e.g., TRP) can estimate the signal to interference plus noise ratio (SINR) (e.g., received SINR). Accordingly, the base station (e.g., TRP) can determine an MCS for UL transmission (e.g., PUSCH / PUCCH transmission).

[0096] SRS quality can refer to the SRS quality measured at the base station. SRS quality can be determined based on the fading of the wireless channel. Fading can be categorized into small-scale fading and large-scale fading. The distance between a terminal and a TRP can fall into the large-scale fading category. SRS coverage can refer to the geographical location(s) of terminal(s) that satisfy a specific quality. The terminal(s) that satisfy a specific quality can be determined using the SINR (or RSRP) measured at the TRP or an implementation metric.

[0097] In conventional communication systems, there may be less need to consider SRS coverage. This is because TRP coverage refers to DL coverage (e.g., SIB coverage). Alternatively, service coverage can be determined using the reception quality of PDCCH at the aggregation level of a common search space set, so there may be less need to consider SRS coverage in conventional communication systems. A terminal can establish an RRC connection with a base station (e.g., TRP). The TRP can estimate large-scale fading using SRS. The terminal can receive configuration information for repeated transmission of UL RS (e.g., the number of repeated transmissions). In other words, the repeated transmission configuration of the UL RS can be indicated to the terminal. The terminal can repeatedly transmit the UL RS. If the UL RS is repeatedly transmitted, the quality of the UL RS (e.g., SRS and / or demodulation-reference signal (DM-RS)) received in the TRP can be improved.

[0098] In the proposed method, a terminal can receive configuration information (e.g., the number of repetition transmissions) for repeated transmission of a UL RS (e.g., SRS) from a serving base station through signaling (e.g., RRC signaling), and can apply the received configuration information to repeated transmission of the UL RS. In other words, the configuration of repeated transmission of the UL RS can be indicated to the terminal by the base station.

[0099] The reception quality of UL RSs (e.g., SRS / DM-RS) in TRP can be improved when "UL RSs have the same number of repeated transmissions and UL coherence is maintained for UL RS transmissions." TRP can estimate the wireless channel by aggregating repeatedly received instances.

[0100] To expand coverage, a terminal can maintain phase continuity and / or phase consistency by aggregating multiple slots or instances. The number of aggregated slots or instances can be determined based on the capabilities of the terminal. The base station can configure (e.g., instruct) the length of the consistency window to the terminal through signaling (e.g., RRC signaling) based on the terminal's capabilities. The terminal can check the length of the consistency window configured (e.g., instructed) by the base station.

[0101] "If the transmission power of the terminal changes," "if the transmission beam of the terminal changes," "if the transmit precoding matrix indicator (TPMI) of the terminal changes," "if the TA changes," and / or "if the terminal performs frequency hopping," phase continuity may not be maintained. In other words, phase noise may occur. Mathematical expression 1 below can represent the relationship between signals transmitted by the terminal (e.g., y[i] and y[j]).

[0102]

[0103] A terminal may transmit different UL signal / channel instances (e.g., SRS instance i and SRS instance j, PUSCH instance i and PUSCH instance j, or PUCCH instance i and PUCCH instance j) on the same radio channel. Due to the transmission of different UL signal / channel instances, phase noise may occur. Phase noise is can be expressed as

[0104] The base station is may not be able to estimate. Therefore, and Each can be estimated independently. Even when the terminal performs repeated transmissions to expand coverage, the base station cannot perform joint channel estimation, but can perform soft combining on the data portion of the PUSCH or the data portion of the PUCCH.

[0105] If consistency is maintained for UL signal / channel instance transmissions within the consistency window (e.g., ), the base station can perform joint channel estimation. To support the above operation, the terminal may not update the TA at the boundary of slots. Alternatively, to support the above operation, the terminal may not update the transmit power. In other words, the TA and transmit power for UL signal / channel instance transmissions transmitted in multiple slots (e.g., consecutive slots) may be the same.

[0106] In the proposed method, a terminal can receive signaling (e.g., RRC signaling) including the settings necessary to maintain consistency in SRS repetitive transmissions. The terminal can repeatedly transmit the SRS based on the settings. The terminal can transmit the SRS using the same power (e.g., the same transmit power) and the same Tx beam on the same subcarrier. In this case, consistency in SRS repetitive transmissions can be maintained.

[0107] For example, one SRS resource may include one or more symbols (e.g., one or more SRS symbols). The SRS symbols included in one SRS resource may correspond to the same SRS port(s). The same power and the same Tx beam may be applied for SRS transmission in the SRS symbols included in one SRS resource. For another example, two or more SRS resources may be considered. The same power and the same Tx beam may be applied for SRS transmissions in different SRS resources. In this case, to maintain the same power, the different SRS resources may be arranged consecutively in the time domain. In other words, the different SRS resources may be configured in a time division multiplexing (TDM) manner. Alternatively, the different SRS resources may be arranged in the same symbols, and the different SRS resources arranged in the same symbols may be distinguished in the frequency domain. In other words, the different SRS resources may be configured in a frequency division multiplexing (FDM) manner. When different SRS resources are distinguished in the time domain, the last symbol of one SRS resource may be adjacent to the first symbol of another SRS resource.

[0108] A UL beam management method in SRS repetitive transmission can be considered. The UL beam pairing procedure (e.g., UL beam management procedure) can be divided into steps U1, U2, and U3. In step U1, the UE can transmit a PRACH, and TRP 0 (or serving base station, serving cell) can receive the PRACH of the UE, and TRP 0 can determine an Rx beam based on the received PRACH. In step U2, the UE can repeatedly transmit a UL signal / channel using the same UL beam, and TRP 0 can select the best Rx beam 0 by testing the Rx beam based on the repeatedly received UL signal / channel. In step U3, the terminal can transmit the UL signal / channel using different UL beams, TRP 0 can receive the UL signal / channel of the terminal through Rx beam 0, and TRP 0 can select the best UL beam of the terminal based on the received UL signal / channel.

[0109] In the U2 phase, the terminal can transmit an UL RS (e.g., an SRS), and the terminal can receive a configuration or instruction for enabling or disabling SRS repeated transmission. An SRS resource set can be configured to be utilized for beam management, and an SRS resource belonging to the SRS resource set can have one port, and the SRS can be repeatedly transmitted in adjacent symbols. TRP 0 can receive the SRS in each of the SRS resources by changing the Rx beams. In the present disclosure, a port associated with an SRS resource (e.g., an SRS transmission) can be an SRS port, and a symbol belonging to the SRS resource (e.g., a symbol on which the SRS is transmitted) can be an SRS symbol.

[0110] Figure 4 is a conceptual diagram illustrating a first embodiment of SRS resources.

[0111] Referring to FIG. 4, an SRS resource may have four ports. A terminal may transmit an SRS using the four ports in the same frequency resource. The SRS may be transmitted in adjacent symbols. The number of ports of the SRS resource may be equal to the number of symbols belonging to the SRS resource (e.g., the number of symbols in which the SRS is transmitted). SRS transmission for four ports may be performed in one symbol. Since SRS transmission in symbols belonging to the SRS resources (e.g., SRS symbols) must be demodulated based on a code division multiplexing (CDM) method, consistency in SRS transmission must be maintained.

[0112] Figure 5 is a conceptual diagram illustrating a second embodiment of SRS resources.

[0113] Referring to FIG. 5, an SRS resource may have two ports. SRS transmissions may be performed on a first SRS resource and a second SRS resource. The same resource (or the same SRS transmission) may be repeated on the first SRS resource and the second SRS resource. Alternatively, the first SRS resource and the second SRS resource may be different resources. Different SRS transmissions may be performed on the first SRS resource and the second SRS resource. Consistency in SRS transmissions on the same resource may be maintained, but consistency in SRS transmissions on different resources may not be maintained. Even when the same resource is repeated, consistency may not be maintained between SRS resources.

[0114] Figure 6 is a conceptual diagram illustrating a third embodiment of SRS resources.

[0115] Referring to FIG. 6, an SRS resource may have one port, and an SRS resource having one port may be repeated four times. To perform step U2 of the UL beam management procedure, an SRS transmission may be repeated four times in an SRS resource consisting of one symbol. In other words, the SRS transmission may be repeated in each of the four SRS resources. The SRS may be transmitted in consecutive symbols. In repeated SRS transmissions, the UL beam (e.g., Tx beam) of the terminal may be maintained. In other words, the terminal may repeatedly transmit the SRS using the same UL beam. Consistency may not be maintained between SRS symbols.

[0116] With the proposed method, a terminal can transmit SRS on two or more SRS resources, and consistency of SRS transmissions on the two or more SRS resources can be maintained. Separate signaling (e.g., RRC signaling including configuration for maintaining consistency) can be instructed to the terminal. Different SRS resources can be configured on the same subcarrier, and the same power and / or the same Tx beam can be applied to different SRS resources.

[0117] The SRS port of each consistent SRS transmission can be utilized for joint channel estimation. Since SRS transmissions with the same SRS port are received at preset time intervals, the mobility of the terminal can be estimated based on the received SRS transmissions. If the terminal maintains consistency in SRS transmissions, the embodiments of FIGS. 3 through 6 may imply equivalent transmission and reception operations.

[0118] Figure 7 is a conceptual diagram illustrating a first embodiment of a TRS (tracking reference signal) resource.

[0119] Referring to Fig. 7, in order to estimate the mobility of a terminal, a preset time interval may be required to sufficiently reflect the mobility of the terminal. A TRS resource consisting of CSI-RS symbol(s) may be considered. The TRS may be a CSI-RS for tracking. The TRS may have the same CSI-RS port. The TRS may be configured in units of four symbols. Two of the four symbols may be configured as CSI-RS symbols. The terminal may perform link management operations using the TRS. Since the terminal moves during the interval between CSI-RS symbols in the time domain, the quality of the wireless channel may be assumed to change. Therefore, the terminal can offset the Doppler effect, and the terminal can utilize the estimated wireless channel quality for demodulation of other DL signals / channels.

[0120] To estimate the mobility of a terminal, the same SRS port can be applied to the terminal's SRS transmissions during a preset time interval. In the proposed method, SRS transmissions can be performed on specific symbol(s) within an SRS resource, and SRS transmissions can be dropped on other symbol(s) within an SRS resource.

[0121] In the proposed method, when one SRS resource includes multiple symbols, the terminal can transmit the SRS in the first symbol and the last symbol among the multiple symbols, and may not transmit the SRS in the remaining symbol(s) except for the first symbol and the last symbol among the multiple symbols.

[0122] Figure 8 is a conceptual diagram illustrating a first embodiment of an SRS transmission method.

[0123] Referring to FIG. 8, an SRS resource may include two or more symbols. A terminal may transmit an SRS in the first and fourth symbols within the SRS resource, and may not transmit an SRS in the remaining symbols (e.g., the second and third symbols) within the SRS resource. Consistency in SRS transmission in the first and fourth symbols within the SRS resource may be maintained. The same SRS port may be applied to the first and fourth symbols within the SRS resource.

[0124] With the proposed method, the terminal can transmit the SRS using some ports (e.g., some SRS ports) in the first symbol within the SRS resource. For example, the terminal can transmit the SRS using only one port belonging to (e.g., associated with) the SRS resource. Alternatively, if the SRS resource is associated with one or more Tx panels, one port (e.g., one SRS port) can be assigned to each Tx panel. In this case, the terminal can transmit the SRS using two or more ports in the same symbol.

[0125] If an SRS resource includes four or more symbols, the number of SRS ports may be four. SRS transmission may be performed in a CDM manner using four SRS ports in each symbol. If an SRS resource has N ports (e.g., N SRS ports), SRS transmission may be performed in a CDM manner using all ports (e.g., N ports) in N symbols. If an SRS resource has M ports (e.g., M SRS ports), SRS may not be transmitted in N symbols. If an SRS transmission is dropped (e.g., M > N), a case where an SRS is not transmitted in a symbol may occur. Each of N and M may be a natural number.

[0126] When an SRS resource has a single port, the SRS may not be transmitted across two or more symbols. According to the proposed method, even if the SRS resource includes N resources, the terminal can transmit the SRS using the same port at preset time intervals. For example, the terminal can transmit the SRS using one port across four symbols.

[0127] In the embodiment of FIG. 8, the terminal may transmit SRS on some symbols within the SRS resource, and the SRS transmission may be performed using some ports. For example, SRS transmission using one port may be performed twice. The terminal may transmit SRS using the CDM method using two ports. In this case, the SRS transmission may be performed twice. The two ports may have a cross-polarization relationship. If the fading characteristics of the two ports are identical except for the cross-polarization characteristics, the base station can efficiently determine the mobility of the terminal.

[0128] With the proposed method, the terminal can maintain consistency between SRS symbols belonging to one SRS resource.

[0129] To maintain consistency between SRS symbols, a terminal may maintain constant power (e.g., transmit power). If a terminal transmits an SRS in some symbol(s) within an SRS resource and does not transmit an SRS in other symbol(s) within the SRS resource, consistency may not be maintained because the SRS transmit power will change.

[0130] In this case, additional capabilities may be introduced in the terminal. The terminal may transmit information indicating that the terminal has additional capabilities to the serving base station. The serving base station may determine that the terminal has additional capabilities based on the information received from the terminal. The additional capabilities of the terminal may be activated. The additional capabilities of the terminal may be activated by the terminal and / or the base station. Consistency may be a necessary condition for deriving time offsets, frequency offsets, and / or phase offsets. If joint channel estimation is not performed using SRS symbols (e.g., SRS transmissions), the requirement for consistency may be relaxed.

[0131] With the proposed method, time offset, frequency offset, and / or phase offset can be derived even when the transmit power allocated to an SRS symbol changes while an SRS transmission is being performed, provided that other condition(s) for consistency are satisfied.

[0132] To maintain consistency, different UL signals / channels may not be transmitted between SRS symbols. For example, the UL signals / channels may include UL signals / channels scheduled by DCI (e.g., PUSCH, PUCCH, PRACH, SRS) and / or UL signals / channels scheduled by higher layers (e.g., configured grant (CG) PUSCH, PUCCH, PRACH, SRS). The SRS may be different from the SRS resources for which consistency is desired.

[0133] The terminal may receive information indicating a port (e.g., an SRS port) used for SRS transmission via signaling (e.g., RRC signaling). The port indicated by the signaling may be at least one port among the port(s) belonging to the SRS resource. The port with the lowest index among the port(s) belonging to the SRS resource may be used for SRS transmission. Alternatively, the terminal may receive signaling (e.g., RRC signaling) indicating that association is maintained between two or more SRS resources. The SRS port may correspond to a Tx panel of the terminal and / or a port associated with the Tx panel.

[0134] A single spatial relation information or TCI state can be applied to an SRS resource. With the proposed method, two or more ports belonging to a single SRS resource can correspond to different spatial relation information or different TCI states, and SRS transmission can be performed simultaneously using two or more ports. Alternatively, two or more spatial relation information or two or more TCI states can be applied to a single port.

[0135] In the proposed method, when two or more signals / channels are associated in one SRS port, the two or more signals / channels may be composed of SSB, DL RS (e.g., CSI-RS for CSI, CSI-RS for tracking, CSI-RS for beam management, etc.), or SRS. Different types of signals / channels may not be associated. SSB, DL RS, and SRS associated with an SRS port may belong to the same resource set. Although there is no concept of resource set for SSB, SSB may have the same EPRE (energy per resource element), the same period, and / or the same slot offset. Even when a terminal transmits an SRS using one SRS port, the base station may regard that the terminal has transmitted the SRS using two or more Tx panels.

[0136] With the proposed method, SRS can be transmitted simultaneously on two or more SRS resources. When a terminal simultaneously transmits SRS using two or more Tx panels, different SRS resources can correspond to the two or more Tx panels. The different SRS resources can belong to the same resource set (e.g., the same SRS resource set) or different resource sets (e.g., different SRS resource sets).

[0137] The interval between symbols for SRS transmission can be set (e.g., indicated) to the terminal via signaling (e.g., RRC signaling). Alternatively, the interval between symbols for SRS transmission can be derived based on the number of ports that the SRS resource has. Alternatively, the interval between symbols for SRS transmission can be determined based on technical specifications.

[0138] Figure 9 is a conceptual diagram illustrating a second embodiment of an SRS transmission method.

[0139] Referring to Fig. 9, SRS transmission can be performed in multiple SRS symbols. The interval between SRS symbols can be Δ. Consistency can be maintained for all SRS symbols. Δ can be set in units of symbols, sub-slots, or slots. The base station can indicate (e.g., configure) information about Δ to the terminal. The terminal can check Δ indicated (e.g., configured) by the base station. For example, if an SRS resource has N ports, SRS transmission can be performed using specific port(s), and the symbol(s) on which SRS transmission is performed can be determined as the first symbol and the last symbol within the SRS resource. Δ can be derived based on technical specifications.

[0140] A sub-slot may contain two, seven, or fourteen symbols. The base station may configure (e.g., instruct) the terminal to indicate the length of the sub-slot by signaling (e.g., via RRC signaling). The terminal may check the length of the sub-slot indicated by the base station. The length of the sub-slot may be determined based on technical specifications.

[0141] With the proposed method, two or more SRS transmissions can be simulated using SRS resources. When SRS transmissions are performed in SRS symbols with Δ within the same slot (e.g., one slot), the SRS transmissions can be performed in one SRS resource or multiple SRS resources. The first SRS symbol and the first SRS symbol Subsequent SRS symbols can belong to one slot. N can be a natural number.

[0142] Figure 10 is a conceptual diagram illustrating a third embodiment of an SRS transmission method.

[0143] Referring to Figure 10, SRS transmission can be performed twice within a slot.

[0144] Figure 11 is a conceptual diagram illustrating a fourth embodiment of an SRS transmission method.

[0145] Referring to FIG. 11, SRS transmissions can be performed in SRS symbols within adjacent slots. The SRS resource(s) belonging to different slots can refer to two or more SRS resources. This is because the SRS resource can include consecutive symbols, and the same power and the same TA are maintained in the SRS resource.

[0146] At slot boundaries (or subframe boundaries), TPCs may be re-reflected, and TAs may be re-reflected. Consistency is not expected to be maintained at slot boundaries (or subframe boundaries). Consistency is also not expected to be maintained when other UL signals / channels are transmitted. For a base station to utilize SRS for link management, it is desirable to maintain consistency even when SRS resource(s) belong to different slots (or different subslots).

[0147] With the proposed method, consistency of SRS transmission(s) in SRS resource(s) belonging to different slots (or different sub-slots) can be expected to be maintained. One SRS resource can be repeated in different slots (or different sub-slots). Alternatively, the first SRS resource and the second SRS resource can be sequentially configured in different slots (or different sub-slots).

[0148] When a single SRS resource is repeated, only one value (e.g., 2 times) of the repetition factor (N) can be used for link management at the base station. In this case, the repetition factor (N) can be fixed to n2 (e.g., 2 times), and signaling (e.g., RRC signaling) indicating the enablement or disabling of the repetition factor (N) or signaling (e.g., RRC signaling) indicating the presence or absence of the repetition factor (N) can be transmitted from the base station to the terminal. n2 can be indicated by 1 bit of information. The operation of maintaining consistency can be enabled or disabled. The combination of the operation of maintaining consistency and the repetition factor (N) can be indicated to the terminal.

[0149] The configuration information of the SRS resource set may include at least a triggering method of the SRS resource (e.g., periodic, semi-persistent, aperiodic). One or more SRS resources belonging to the SRS resource set may include information about at least one of a different number of ports, different UL / joint TCIs, different spatial relationships, different power, slots in which different SRS resources are configured, or periods of different SRS resources.

[0150] The usage of SRS resources to which the proposed methods are applied may be limited to beam management. Alternatively, the usage of SRS resources to which the proposed methods are applied may be limited to antenna switching.

[0151] A port may be repeated, but a port may not be repeated in consecutive symbols. Since a preset interval (Δ) is applied between symbols, repetition indications can be applied separately. When repetition is indicated in an SRS resource, the conventional repetition and the proposed repetition may not be set simultaneously.

[0152] In the proposed method, link management can be introduced for the use of a set of SRS resources. The set of SRS resources can include one or more SRS resources, and among the one or more SRS resources, one indicated SRS resource can be repeated.

[0153] Deferring PUSCH transmission may be supported. Based on the pattern of UL resources (e.g., slot pattern, TDD configuration), PUSCH transmission may not be performed. In this case, PUSCH transmission may not be dropped and may be deferred. PUSCH transmission may be performed in a subsequent slot. Deferring PUSCH transmission may be applied to SRS transmission. The first symbol in which SRS is transmitted may not be changed within the slot, and the slot in which SRS is transmitted may be deferred. SRS transmission and available slot counting in SRS resources may be applied differently from the existing technical specifications.

[0154] When repeating SRS transmissions in a single SRS resource, the delay operation of the SRS transmission may be used to derive the slot to which the first symbol of the first instance of the SRS resource belongs. A separate delay operation may not be applied to subsequent instances of the SRS resource (e.g., the second instance). A gap of Δ may be maintained between the first and second instances.

[0155] If a method for maintaining consistency while performing SRS transmissions on different SRS resources is applied, a postponement operation may not be applied for SRS transmission on a second SRS resource following the first SRS resource. In other words, a postponement operation for SRS transmission on the first SRS resource may be applied. If a postponement operation for SRS transmission on the first SRS resource is applied, the same postponement operation for SRS transmission on the second SRS resource may be applied. Alternatively, a postponement operation for SRS transmission on the first SRS resource may not be applied, and a postponement operation for SRS transmission on the second SRS resource may be applied. Alternatively, postponement operations for SRS transmission on the first SRS resource and the second SRS resource may not be applied.

[0156] Changes in the transmission of UL signals / channels other than SRS or in accordance with instructions related to the pattern of UL resources (e.g., slot patterns or TDD configurations) may be applied to each of the first SRS resource and the second SRS resource. In this case, at least SRS transmissions may be dropped. Dropping of SRS transmissions may be performed on a symbol-by-symbol basis.

[0157] If SRS transmission is dropped in some symbols, the time window (e.g., the actual time domain window) to maintain consistency may be restarted. This operation (e.g., restarting the time window) may be applied when SRS is transmitted in three or more symbols. This operation may be applied if the terminal's capability for this operation is supported (e.g., enabled).

[0158] When more than one TRP performs cooperative communication, considering non-ideal backhaul and / or Doppler shift / spectrum, it is desirable for SRS resources to be repeated at regular intervals. If consistency is maintained during SRS transmission, SRS can be utilized for downlink coordinated joint transmission (CJT) as well as link management.

[0159] Figure 12 is a flowchart illustrating a second embodiment of a communication method between a terminal and a TRP.

[0160] Referring to FIG. 12, TRPs with non-ideal backhauls can perform CJT. TRP 0 may be a serving base station. TRP 0 and TRP 1 may perform CJT. The terminal may transmit a first SRS to one or more TRPs (S1201). The terminal may transmit a second SRS to one or more TRPs (S1202). The first SRS transmission may mean a first UL RS (uplink reference signal) transmission, and the second SRS transmission may mean a second UL RS transmission. Multiple SRS transmissions (e.g., the first SRS transmission and the second SRS transmission) may be performed at the request of TRP 0 and / or TRP 1. For example, TRP 0 and / or TRP 1 may transmit a message requesting multiple SRS transmission (e.g., multiple UL RS transmission) to the terminal, and the terminal may perform multiple SRS transmission based on the request of TRP 0 and / or TRP 1. If multiple SRS transmission is not requested, the terminal may transmit one SRS (e.g., the first SRS).

[0161] The second SRS may be transmitted after a preset time from the transmission time of the first SRS. The interval between SRS transmissions (e.g., the preset time, Δ) may be configured (e.g., instructed) to the terminal via signaling (e.g., RRC signaling). The terminal may transmit two or more SRSs according to the preset time interval. Consistency and / or continuity may be maintained for the first SRS transmission and the second SRS transmission. In other words, consistency may mean consistency (e.g., sameness) for at least one of TA (timing advance), transmit power, Tx beam, spatial relationship, TCI state, or frequency resource for the first SRS transmission and the second SRS transmission. Continuity may mean phase continuity for the first SRS transmission and the second SRS transmission. While consistency for the first SRS transmission and the second SRS transmission is maintained, the power level (e.g., transmit power level) may not be updated. The first SRS transmission and the second SRS transmission may be repeated transmissions performed on the same SRS resource. The first SRS transmission and the second SRS transmission may be performed on different SRS resources. The different SRS resources may belong to the same SRS resource set or different SRS resource sets. The first SRS transmission and the second SRS transmission may be transmitted in the same slot or different slots.

[0162] Consistency can be maintained for the first SRS transmission and the second SRS transmission. The terminal can transmit the first SRS and the second SRS using the same power and / or the same Tx beam on the same subcarrier. Each of TRP 0 and TRP 1 can receive SRS(es) (e.g., the first SRS and / or the second SRS) from the terminal and derive information necessary for link management based on the received SRS(es). The information necessary for link management can include a time offset, a frequency offset, and / or a phase offset. Each of the time offset, the frequency offset, and the phase offset can be derived based on a difference between the first SRS and the second SRS. The time offset can mean a time difference, the frequency offset can mean a frequency difference, and the phase offset can mean a phase difference.

[0163] TRP 0 can perform a compensation operation for time / frequency / phase synchronization using information derived based on SRS(es) (S1203-1). TRP 1 can perform a compensation operation for time / frequency / phase synchronization using information derived based on SRS(es) (S1203-2). For example, each of TRP 0 and TRP 1 can derive a difference according to a time interval between a first SRS transmission and a second SRS transmission, and perform a compensation operation for time synchronization and / or phase synchronization based on the derived difference. The difference according to the time interval may correspond to a phase difference. Each of TRP 0 and TRP 1 can derive a difference between the power of the first SRS (e.g., transmit / receive power) and the power of the second SRS (e.g., transmit / receive power), and perform a compensation operation for time synchronization and / or phase synchronization based on the derived difference. The power difference between the SRSs may correspond to a phase difference.

[0164] TRPs can exchange information derived using a backhaul (e.g., a non-ideal backhaul). For example, TRP 0 can derive a first difference (e.g., a time difference, a power difference, a phase difference, etc.) between a first SRS and a second SRS and transmit information about the first difference to TRP 1. TRP 1 can obtain information about the first difference from TRP 0. TRP 1 can derive a second difference (e.g., a time difference, a power difference, a phase difference, etc.) between the first SRS and the second SRS and transmit information about the second difference to TRP 0. TRP 0 can obtain information about the first difference from TRP 1. Each of TRP 0 and TRP 1 can perform a compensation (e.g., a pre-compensation) operation for time / frequency / phase synchronization based on the first difference and the second difference.

[0165] Alternatively, information derived based on SRS(s) can be communicated to a TRP (e.g., a TRP other than TRP 0 and TRP 1) or to a base station (e.g., a digital unit (DU) or a central unit (CU)). The difference between the time offset of TRP 0 and the time offset of TRP 1 can be derived based on information derived based on SRS(s). The difference between the frequency offset of TRP 0 and the frequency offset of TRP 1 can be derived based on information derived based on SRS(s). The difference between the phase offset of TRP 0 and the phase offset of TRP 1 can be derived based on information derived based on SRS(s). The difference between the time offsets of TRPs, the difference between the frequency offsets of TRPs, and / or the difference between the phase offsets of TRPs can be derived by any TRP or any base station having information derived based on SRS(s). Differences derived by any TRP or any base station (e.g., differences between time offsets, differences between frequency offsets, differences between phase offsets) can be transmitted to TRP 0 and TRP 1.

[0166] Each of TRP 0 and TRP 1 can derive the difference between the time offsets of the TRPs, the difference between the frequency offsets of the TRPs, and / or the difference between the phase offsets of the TRPs based on information derived based on the SRS(es). If the difference between the time offsets of the TRPs, the difference between the frequency offsets of the TRPs, and / or the difference between the phase offsets of the TRPs is derived from a TRP or a base station other than TRP 0 and TRP 1, the other TRP or base station can inform TRP 0 and TRP 1 of the difference between the time offsets of the TRPs, the difference between the frequency offsets of the TRPs, and / or the difference between the phase offsets of the TRPs. In S1204, TRP 0 and TRP 1 can perform a compensation operation (e.g., a pre-compensation operation) for time / frequency / phase synchronization based on the difference between the time offsets of the TRPs, the difference between the frequency offsets of the TRPs, and / or the difference between the phase offsets of the TRPs.

[0167] A pre-compensation operation may be performed for PDSCH transmission. TRP 0 and / or TRP 1 may derive information necessary for the pre-compensation operation to transmit PDSCH based on the CJT method. TRP 0 and / or TRP 1 may perform a pre-compensation operation for PDSCH. TRP 0 and TRP 1 may transmit PDSCH in the CJT method (S1205). A terminal may receive PDSCH from TRP 0 and TRP 1. Since the pre-compensation operation for PDSCH is performed in TRP 0 and / or TRP 1, at least the frequency offset estimation / compensation procedure in the PDSCH reception procedure of the terminal may be simplified or omitted.

[0168] Even if downlink CJT is not performed when the terminal has mobility, it is desirable for one TRP (e.g., TRP 0 or TRP 1) to track / estimate the mobility of the terminal, and it is desirable for one TRP (e.g., TRP 0 or TRP 1) to perform estimation / offset operation based on the mobility of the terminal. Since the first SRS transmission and the second SRS transmission maintain consistency, it is desirable for the SRS to be utilized as an uplink TRS.

[0169] The serving base station (or TRP 0, TRP 1) can receive the first SRS and the second SRS from the terminal, and can derive the difference between the wireless channel estimated based on the first SRS and the wireless channel estimated based on the second SRS. Referring to the above mathematical expression 1, the first SRS is can experience, and the second SRS can be experienced. In cases where the terminal does not move, the difference in small-scale fading may not be significant, and consistency is maintained. can be interpreted as

[0170] The difference between wireless channels can be captured by small-scale fading within the wireless channel. Depending on the mobility of the terminal, small-scale fading can indicate a certain difference. This difference can be used as an indicator for determining the mobility of the terminal at the serving base station.

[0171] The consistency maintained by the terminal may be necessary to derive the difference in small-scale fading at the serving base station. If the terminal transmits the first SRS and the second SRS without maintaining consistency, referring to the above mathematical expression 1, since, may not be established.

[0172] In a network (e.g., a communication system) in which multiple TRPs (e.g., mTRPs (multiple-TRPs)) are deployed, when a terminal transmits an SRS, a first TRP (e.g., TRP 0) and a second TRP (e.g., TRP 1) can receive the SRS. A wireless channel estimated by the first TRP based on the received SRS may be different from a wireless channel estimated by the second TRP based on the received SRS. Even when the mobility of the terminals is commonly reflected, it is difficult for the first TRP and the second TRP to estimate a time offset, a frequency offset, and / or a phase offset between each other, and therefore, the wireless channels estimated by the first TRP and the second TRP may be different from each other.

[0173] When the terminal transmits the first SRS and the second SRS at preset time intervals, the first TRP and the second TRP can confirm the mobility of the terminal based on the first SRS and the second SRS, and the first TRP and the second TRP can estimate a time offset, a frequency offset, and / or a phase offset between each other through information exchange via the backhaul.

[0174] In order for the first TRP and the second TRP to verify the mobility of the terminal using only the first SRS received from the terminal, the frequencies of the oscillators of the first TRP and the second TRP must be synchronized. If the frequencies between the TRPs are not synchronized, the estimation result based on the received first SRS may be the sum of the frequency offset of the oscillator and the Doppler frequency. In other words, the frequency and the Doppler frequency of the oscillator may not be estimated separately. If the frequency and the Doppler frequency of the oscillator can be estimated separately, the first TRP and the second TRP can obtain frequency synchronization by canceling out the frequency offset. If the frequencies between the first TRP and the second TRP are not synchronized, it may be assumed that the frequency offset between the TRPs is not estimated.

[0175] In this situation, the pre-compensated frequency offset in the first and second TRPs may be incomplete. Therefore, if the Doppler effect reoccurs in the downlink, the terminal may receive a PDSCH with a frequency offset. In other words, even if the first and second TRPs pre-compensate for the frequency offset by exchanging information through the backhaul, the Doppler effect may not be offset in advance.

[0176] The terminal The frequency that I think of is It can be. The terminal frequency When the first SRS is transmitted from the first TRP, the frequency of the first SRS received from the first TRP is It could be. silver can have a relationship, Is can have a relationship. The terminal is You may not know the value of and may not be able to manage the frequency.

[0177] When one TRP receives a PUSCH or PUCCH from a terminal, There is no need to distinguish each element (e.g., instability of the oscillator (e.g., frequency of the oscillator), Doppler effect (e.g., Doppler frequency)). The terminal and the TRP may not demodulate / decode only the UL signal / channel, and the DL channel can be estimated based on the SRS. In a communication system supporting TDD, the burden of CSI-RS and CSI reporting can be reduced by utilizing UL-DL reciprocity, and SRS can be used instead of CSI-RS and CSI reporting. The terminal has and the Doppler effect ( ) is not pre-compensated, the frequency offset may not be offset. The serving base station Since only the frequency offset is estimated, the serving base station may not be able to transmit the DL signal / channel with the frequency offset pre-compensated to the terminal. The serving base station can obtain information about the DL using the SRS based on time synchronization and / or spatial beam reciprocity without frequency synchronization.

[0178] Two or more TRPs can transmit PDSCH to the terminal. Two or more TRPs can transmit PDSCH to the terminal after pre-compensating the frequency offset. Two or more TRPs can pre-compensate the frequency offset by exchanging information through the backhaul (e.g., Xn interface or Nn interface), but two or more TRPs can compensate for the error ( ) because we do not know the Doppler effect ( , ) cannot be estimated. The first TRP is an error due to the oscillator of the terminal ( ) is unknown, and It is not possible to measure the difference between the two. The second TRP is The UL signal / channel of the terminal can be received. Is , but the second TRP has a relationship with and It cannot be measured by distinguishing between them.

[0179] Even if the first and second TRPs achieve frequency synchronization by exchanging information through the backhaul, it can be difficult to distinguish between the Doppler effect and the terminal's own error. For pre-compensated PDSCH transmission, a procedure to isolate only the Doppler effect may be necessary.

[0180] The operations of the method according to the embodiments of the present disclosure can be implemented as a computer-readable program or code on a computer-readable recording medium. A computer-readable recording medium includes any type of recording device that stores information readable by a computer system. Furthermore, a computer-readable recording medium can be distributed across network-connected computer systems, allowing the computer-readable program or code to be stored and executed in a distributed manner.

[0181] Additionally, the computer-readable recording medium may include hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, etc. The program instructions may include not only machine language codes produced by a compiler, but also high-level language codes that can be executed by a computer using an interpreter, etc.

[0182] While some aspects of the present disclosure have been described in the context of a device, they may also represent a description of a corresponding method, wherein a block or device corresponds to a method step or a feature of a method step. Similarly, aspects described in the context of a method may also be described as a corresponding block or item or a feature of a corresponding device. Some or all of the method steps may be performed by (or using) a hardware device, such as, for example, a microprocessor, a programmable computer, or an electronic circuit. In some embodiments, at least one or more of the most significant method steps may be performed by such a device.

[0183] In embodiments, a programmable logic device (e.g., a field-programmable gate array) may be used to perform some or all of the functions of the methods described herein. In embodiments, the field-programmable gate array may operate in conjunction with a microprocessor to perform one of the methods described herein. In general, the methods are preferably performed by some hardware device.

[0184] Although the present disclosure has been described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various modifications and changes may be made to the present disclosure without departing from the spirit and scope of the present disclosure as set forth in the claims below.

Claims

1. As a terminal method, A step of transmitting a first UL RS (uplink reference signal) to one or more transmission and reception points (TRPs); A step of transmitting a second UL RS to one or more TRPs after a preset time from the transmission time of the first UL RS; and A step of receiving a compensated DL (downlink) channel based on the first UL RS and the second UL RS from the one or more TRPs, Consistency in transmission of the above first UL RS and the above second UL RS is maintained. Terminal method.

2. In claim 1, Further comprising the step of receiving a message requesting multiple UL RS transmissions from at least one TRP among the one or more TRPs, Transmission for the first UL RS and the second UL RS is performed based on the request. Terminal method.

3. In claim 1, The DL channel is compensated based on a first difference between the first UL RS and the second UL RS received in a first TRP among the one or more TRPs and a second difference between the first UL RS and the second UL RS received in a second TRP among the one or more TRPs. Terminal method.

4. In claim 3, The first difference and the second difference are each a time difference according to a time interval between the transmission of the first UL RS and the transmission of the second UL RS, and the time difference corresponds to a phase difference. Terminal method.

5. In claim 3, The first difference and the second difference are each a power difference between the power of the first UL RS and the power of the second UL RS, and the power difference corresponds to a phase difference. Terminal method.

6. In claim 1, The above DL channel is a DL channel in which at least one of time offset, frequency offset, or phase offset is compensated. Terminal method.

7. In claim 1, The above consistency includes at least one of the same TA (timing advance) or the same transmit power. Terminal method.

8. In claim 1, Phase continuity for transmission of the first UL RS and the second UL RS is maintained. Terminal method.

9. As a method of the first TRP (transmission and reception point), A step of receiving a first UL RS (uplink reference signal) from a terminal; A step of receiving a second UL RS from the terminal after a preset time from the time of receiving the first UL RS; A step of compensating a DL (downlink) channel based on the first UL RS and the second UL RS; and A step of transmitting the above DL channel to the terminal is included, Consistency in transmission of the above first UL RS and the above second UL RS is maintained. Method of the first TRP.

10. In claim 9, Further comprising the step of transmitting a message requesting multiple UL RS transmissions to the terminal, Transmission for the first UL RS and the second UL RS is performed based on the request. Method of the first TRP.

11. In claim 9, The step of compensating the above DL channel is: A step of deriving a first difference between the first UL RS and the second UL RS; A step of receiving information on a second difference between the first UL RS and the second UL RS received from the second TRP; and Comprising a step of compensating the DL channel based on the first difference and the second difference, Method of the first TRP.

12. In claim 11, The first difference and the second difference are each a time difference according to a time interval between the first UL RS and the second UL RS, and the time difference corresponds to a phase difference. Method of the first TRP.

13. In claim 11, The first difference and the second difference are each a power difference between the first UL RS and the second UL RS, and the power difference corresponds to a phase difference. Method of the first TRP.

14. In claim 11, The above consistency includes at least one of the same TA (timing advance) or the same transmit power. Method of the first TRP.

15. In claim 11, Phase continuity for transmission of the first UL RS and the second UL RS is maintained. Method of the first TRP.

16. As a terminal, Contains at least one processor, At least one processor of the terminal, Transmitting a first UL RS (uplink reference signal) to one or more transmission and reception points (TRPs); Transmitting a second UL RS to one or more TRPs after a preset time from the transmission time of the first UL RS; and Causing to receive a compensated DL (downlink) channel based on the first UL RS and the second UL RS from the one or more TRPs, Consistency in transmission of the above first UL RS and the above second UL RS is maintained. Terminal.

17. In claim 16, At least one processor of the terminal, further causes receiving a message requesting multiple UL RS transmissions from at least one TRP among the one or more TRPs; Transmission for the first UL RS and the second UL RS is performed based on the request. Terminal.

18. In claim 16, The DL channel is compensated based on a first difference between the first UL RS and the second UL RS received in a first TRP among the one or more TRPs and a second difference between the first UL RS and the second UL RS received in a second TRP among the one or more TRPs. Terminal.

19. In claim 18, The first difference and the second difference are each a time difference according to a time interval between the transmission of the first UL RS and the transmission of the second UL RS, and the time difference corresponds to a phase difference. Terminal.

20. In claim 18, The first difference and the second difference are each a power difference between the power of the first UL RS and the power of the second UL RS, and the power difference corresponds to a phase difference. Terminal.

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