Method and apparatus for transmitting and receiving uplink reference signal in a wireless communication system

Abstract

A terminal used in a wireless communication system and a method performed by the terminal are provided. The method includes receiving configuration information associated with a sounding reference signal (SRS) through higher layer signaling; receiving first DL control information (DCI); and sending the SRS in an available time slot from a reference time slot based on the first DCI.

Description

Technical Field

[0001] The present disclosure generally relates to methods and apparatus for transmitting and receiving an uplink (UL) reference signal in a wireless communication system. Background Art

[0002] In order to meet the growing demand for wireless data services since the commercialization of the fourth generation (4G) communication system, efforts have been made to develop an enhanced fifth generation (5G) communication system or a quasi-5G communication system. The 5G communication system or the quasi-5G communication system may also be referred to as a "super 4G network communication system" or a "post-long term evolution (LTE) system".

[0003] In order to increase the data rate, it is considered to implement the 5G communication system in an ultra-high frequency band (millimeter wave (mmW)) (for example, 60 GHz).

[0004] In order to reduce the path loss of radio waves and increase the transmission distance of radio waves in the ultra-high frequency band, technologies such as beamforming, massive multiple-input multiple-output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive antennas have been discussed for 5G communication systems.

[0005] In order to improve the system network, for 5G communication systems, technologies such as evolved small cells, advanced small cells, cloud radio access networks (RAN), ultra-dense networks, device-to-device (D2D) communications, wireless backhaul, mobile networks, cooperative communications, coordinated multi-point (CoMP), and interference cancellation have been developed. For 5G communication systems, advanced coding modulation (ACM) schemes such as hybrid frequency shift keying (FSK) and quadrature amplitude modulation (QAM) modulation (FQAM) have been developed, and sliding window superposition coding (SWSC) and enhanced network access schemes such as filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) have also been developed.

[0006] The Internet is developing into an Internet of Things (IoT) network, where distributed elements exchange and process information. The Internet of Everything (IoE) technology, which combines IoT technology and big data processing technology by connecting to cloud servers, is also emerging.

[0007] To realize IoT, technical elements such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology are required, so technologies for inter-object connectivity such as sensor networks, machine-to-machine (M2M) communication, or machine type communication (MTC) have been recently studied.

[0008] In the IoT environment, intelligent Internet technology services that collect and analyze data generated by connected objects can be provided. Through the fusion and integration of existing information technology (IT) and various industries, the IoT can be applied to smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, healthcare, smart appliances, and advanced medical services.

[0009] Various attempts have been made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, M2M communications, and MTC are implemented through 5G communication technologies such as beamforming, MIMO, and array antennas. The application of cloud RAN as a big data processing technology can also be considered an example of the fusion of 5G technology and IoT technology.

[0010] As wireless communication systems develop, various services may be provided, and thus a method of smoothly supporting services related to repeated transmission of UL data of a terminal is required. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent from the following description in conjunction with the accompanying drawings, in which:

[0012] Figure 1 shows the basic structure of the time-frequency domain as a wireless resource domain according to an embodiment;

[0013] Figure 2 shows a time slot structure according to an embodiment;

[0014] Figure 3 shows a bandwidth part (BWP) according to an embodiment;

[0015] Figure 4 A method of changing BWP according to an embodiment is shown;

[0016] Figure 5 shows a control resource set (CORESET) in which a DL control channel is transmitted according to an embodiment;

[0017] Figure 6a shows a medium access control (MAC) control element (CE) configuration for activation / deactivation of semi-persistent (SP) SRS according to an embodiment;

[0018] Figure 6b shows a MAC CE configuration for spatial relationship indication of aperiodic (AP) SRS according to an embodiment;

[0019] Figure 7A method according to an embodiment is shown by which a user equipment (UE) determines AP SRS transmission timing by using an offset received based on higher layer configuration information and a new offset for dynamically triggering AP SRS;

[0020] Figure 8 A method according to an embodiment is shown, by which a UE determines AP SRS transmission timing by using a new slot offset for dynamically triggering AP SRS;

[0021] Fig. 9 A method according to an embodiment is shown, by which a UE determines AP SRS transmission timing by dynamically triggering AP SRS using a slot index in a frame;

[0022] Fig.10 It is shown that a UE according to an embodiment changes the AP SRS transmission timing by using an offset for dynamically changing the AP SRS transmission timing and a preconfigured AP SRS transmission timing;

[0023] Fig.11 It is shown that the UE according to the embodiment changes the AP SRS transmission timing by using only the offset for dynamically changing the AP SRS transmission timing;

[0024] Fig.12 It is shown that the UE according to the embodiment changes the AP SRS transmission timing by using only the slot index in the frame for dynamically changing the AP SRS transmission timing;

[0025] Fig.13 shows that a UE according to an embodiment dynamically exchanges timing by using an offset indicating two AP SRS resource sets;

[0026] Fig.14 It is shown that a UE according to an embodiment dynamically exchanges the transmission timing of two AP SRS resource sets and delays the transmission timing of the AP SRS sets by using information indicating the two AP SRS resource sets and the timing delay offset;

[0027] Fig.15 It is shown that a UE according to an embodiment dynamically reorders the transmission timing of three or more AP SRS resource sets by using an offset to reorder the order of triggered AP SRS resources;

[0028] Fig.16 It is shown that a UE according to an embodiment dynamically cancels a single AP SRS resource set by using an offset for canceling a single triggered AP SRS resource set;

[0029] Fig.17It is shown that a plurality of UEs according to an embodiment cancel a triggered AP SRS resource set by using an offset for canceling a triggered AP SRS resource set based on a group;

[0030] Fig.18 It is shown that the UE according to an embodiment cancels all triggered AP SRS resource sets after the indicated time slot;

[0031] Fig.19 It is shown that a UE according to an embodiment transmits an AP SRS by using an automatic delay method;

[0032] Fig. 20 It is shown that the UE according to the embodiment sends the AP SRS based on the indicated available resource index;

[0033] Fig.21 The invention shows a rule for the UE to select the AP SRS resource set to be sent preferentially when the transmission timing of the automatically delayed AP SRS resource set and the newly triggered AP SRS resource set are the same and the AP SRS resource sets cannot be sent at the same time according to an embodiment;

[0034] Fig. 22 The invention shows a rule for the UE to select the AP SRS resource set to be transmitted preferentially when the transmission timings of two AP SRS resource sets triggered based on the available index are the same and the AP SRS resource sets cannot be transmitted simultaneously according to an embodiment;

[0035] Fig.23a A method according to an embodiment is shown, by which a BS configures a DCI for dynamically triggering an AP SRS;

[0036] Figure 23b A method according to an embodiment is shown, by which a BS configures a DCI for dynamically triggering an AP SRS;

[0037] Fig.24 is a flow chart illustrating a process by which a UE triggers an AP SRS by considering higher layer parameters and a DCI-based dynamic AP SRS triggering offset according to an embodiment;

[0038] Fig.25 is a flowchart illustrating a procedure according to an embodiment, by which a UE transmits an AP SRS by considering a DCI for dynamically determining a transmission timing of an AP SRS resource set;

[0039] Fig.26 shows a terminal according to an embodiment;

[0040] Fig. 27 A BS according to an embodiment is shown;

[0041] Fig.28 is a flow chart illustrating a method of a UE according to an embodiment;

[0042] Fig.29 is a flowchart illustrating a method of a BS according to an embodiment;

[0043] Fig.30 shows a MAC CE for indicating activation of an AP SRS resource set according to an embodiment;

[0044] Fig.31 shows a MAC CE for indicating a flexible offset of an AP SRS resource set according to an embodiment;

[0045] Fig.32 A MAC CE for indicating a flexible offset value and an offset operation is shown;

[0046] Fig.33 shows a MAC CE for indicating activation of SRS resources in an AP SRS resource set according to an embodiment;

[0047] Fig.34 is a flow chart showing an AP SRS triggering process according to an embodiment;

[0048] Fig.35 is a flow chart showing an AP SRS triggering process according to an embodiment;

[0049] Fig.36 is a flow chart illustrating a process according to an embodiment by which a BS indicates triggering of an AP SRS and dynamically changes the transmission timing by considering a new slot offset for dynamically determining the timing of the AP SRS based on higher layer parameters and DCI;

[0050] Fig.37 is a flowchart illustrating a process according to an embodiment by which the UE determines the transmission timing of an AP SRS to be transmitted by also considering a slot offset configured by a higher layer parameter and a new slot offset for dynamically determining the timing of the AP SRS based on a DCI together;

[0051] Fig.38 is a flowchart showing a process according to an embodiment, by which a UE determines a triggered transmission timing of an AP SRS and transmits the AP SRS by considering a DCI for dynamically determining the transmission timing of the AP SRS; and

[0052] Fig.39 A method of triggering AP SRS and cancelling the triggering based on time slot configuration according to an embodiment is shown. DETAILED DESCRIPTION

[0053] An aspect of the present disclosure is to provide a method and apparatus for transmitting and receiving a UL reference signal to effectively use a UL (UL) or a downlink (DL) for various services in a mobile communication system.

[0054] According to one aspect of the present disclosure, a method performed by a terminal in a wireless communication system is provided. The method includes receiving configuration information associated with a sounding reference signal (SRS) through higher layer signaling; receiving first DL control information (DCI); and sending the SRS in an available time slot from a reference time slot based on the first DCI.

[0055] According to another aspect of the present disclosure, a terminal for use in a wireless communication system is provided. The terminal includes a transceiver; and a processor configured to receive configuration information associated with an SRS through higher layer signaling; receive a first DCI; and send an SRS in an available time slot from a reference time slot based on the first DCI.

[0056] According to another aspect of the present disclosure, a method performed by a base station (BS) in a wireless communication system is provided. The method includes: sending configuration information associated with an SRS to a terminal through higher layer signaling; sending a first DCI to the terminal; and receiving the SRS in an available time slot from a reference time slot based on the first DCI.

[0057] According to another aspect of the present disclosure, a BS used in a wireless communication system is provided. The BS includes a transceiver; and a processor configured to send configuration information associated with an SRS to a terminal through higher layer signaling; send a first DCI to the terminal; and receive an SRS in an available time slot from a reference time slot based on the first DCI.

[0058] Hereinafter, various embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0059] In the description of the embodiments, technical matters that are well known in the technical field of the present disclosure and are not directly related to the present disclosure will not be described. By omitting unnecessary descriptions, the subject matter of the present disclosure will be described more clearly without being ambiguous.

[0060] Likewise, some elements may be exaggerated, omitted or schematically shown in the accompanying drawings. In addition, the size of each element may not reflect its actual size substantially. In each of the accompanying drawings, the same or corresponding elements are represented by the same reference numerals.

[0061] Throughout the disclosure, the expression "at least one of a, b, or c" may mean only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof.

[0062] Examples of the terminal may include UE, a mobile station (MS), a cellular phone, a smart phone, a computer, a multimedia system capable of performing a communication function, and the like.

[0063] The controller here can also be called a processor.

[0064] A layer (or layer arrangement) may also be referred to as an entity.

[0065] The advantages and features of the present disclosure and the methods for achieving these advantages and features will become apparent with reference to the embodiments described in detail below in conjunction with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below, but may be implemented in different forms. The embodiments described herein are provided to achieve complete disclosure and fully convey the scope of the present disclosure to those of ordinary skill in the art, and the present disclosure may be limited by the scope of the claims.

[0066] The same reference numerals in the specification denote the same elements.

[0067] The terms used herein are defined in consideration of functions used in the present disclosure, and may be changed according to the intention of a user or an operator, precedents, etc. Therefore, the definitions of the terms should be understood based on the entire description of the present specification.

[0068] Hereinafter, BS is an entity that performs resource allocation of a terminal, and may be at least one of a gNode B, an eNode B, a NodeB, a BS, a radio access unit, a BS controller, or a node on a network. The terminal may include a UE, an MS, a cellular phone, a smart phone, a computer, or a multimedia system capable of performing a communication function. In the present disclosure, DL represents a wireless transmission path of a signal sent by a BS to a terminal, and UL represents a wireless transmission path of a signal sent by a terminal to a BS. Although the embodiments of the present disclosure are described by using an LTE or an advanced LTE (LTE-A) system as an example, the embodiments of the present disclosure may also be applied to other communication systems having similar technical backgrounds or channel forms. For example, a 5G mobile communication technology (5G or new radio (NR)) developed after LTE-A may be included, and the following 5G system may include a system including existing LTE, LTE-A, and other similar services. In addition, according to the determination of a person of ordinary skill in the art, without departing from the scope of the present disclosure, the embodiments of the present disclosure may be applied to other communication systems by partial modification.

[0069] Each block of the flowchart diagram and the combination of blocks in the flowchart diagram can be implemented by computer program instructions. These computer program instructions can be installed on a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that the instructions executed by the processor of the computer or other programmable data processing device produce components for performing the functions described in the flowchart (multiple) blocks. These computer program instructions can be stored in a computer executable or computer readable memory, which is intended to enable a computer or other programmable data processing device to implement functions in a specific method, so the instructions stored in the computer executable or computer readable memory can produce a manufactured product including instruction components that perform the functions described in the flowchart (multiple) blocks. Since the computer program instructions can be installed on a computer or other programmable data processing device, a process that can be executed by a computer is generated by executing a series of operating steps on the computer or other programmable data processing device, and the instructions of the computer or other programmable data processing device can provide operations to perform the functions described in the flowchart (multiple) blocks.

[0070] Each block can represent a module, segment or a part of code including one or more executable instructions for performing (multiple) specific logic functions. In some alternative implementations, the functions marked in the box may not appear in order. For example, two blocks shown in succession can be performed substantially simultaneously, or these blocks can sometimes be performed in reverse order, depending on the corresponding function.

[0071] Here, the term "~ unit" refers to a software component or a hardware component that performs a specific task, such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC). However, the term "~ unit" is not limited to software or hardware. The "~ unit" can be configured in an addressable storage medium, or it can be configured to operate one or more processors. Therefore, for example, the "~ unit" may include components, such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcodes, circuits, data, databases, data structures, tables, arrays and variables. The functions provided in the components and "~ units" can be combined into fewer components and "~ units", or further divided into additional components and "~ units". In addition, components and "~ units" can be implemented to operate one or more central processing units (CPUs) in a device or a secure multimedia card. In addition, the "~ unit" may include one or more processors.

[0072] Although the method and apparatus provided as an embodiment of the present disclosure are described as an example of a service for improving coverage, the present disclosure is not limited thereto, and by using a combination of all or some embodiments of the present disclosure, a method of sending and receiving a data channel, a control channel, and a reference signal corresponding to other additional services may be used. Therefore, according to the determination of a person of ordinary skill in the art, the embodiments of the present disclosure may be applied by partial modification without departing from the scope of the present disclosure.

[0073] Wireless communication systems have evolved from initial systems that provided voice-oriented services to broadband wireless communication systems that provide high-speed and high-quality packet data services, using communication standards such as 3rd Generation Partnership Project (3GPP) High Speed ​​Packet Access (HSPA), LTE or Evolved Universal Terrestrial Radio Access (E-UTRA), LTE-A, LTE-Pro, 3GPP2 High Speed ​​Packet Data (HRPD), Ultra Mobile Broadband (UMB), and Institute of Electrical and Electronics Engineers (IEEE) 802.16e.

[0074] As a representative example of a broadband wireless communication system, the LTE system adopts an Orthogonal Frequency Division Multiplexing (OFDM) scheme for DL ​​and a Single Carrier Frequency Division Multiple Access (SC-FDMA) scheme for UL.

[0075] In the above-mentioned multiple access scheme, time-frequency resources for carrying data or control information are allocated and operated in a manner to prevent resource overlap, that is, orthogonality between users is established so as to identify the data or control information of each user.

[0076] As a future communication system, after LTE, the 5G communication system should be able to freely reflect the various needs of users and service providers, and therefore should support services that meet various needs at the same time. The services considered for the 5G communication system include enhanced mobile broadband (eMBB), massive MTC (mMTC), and ultra-reliable low-latency communication (URLLC).

[0077] The goal of eMBB is to provide a higher data rate than that supported by conventional LTE, LTE-A or LTE-Pro. For example, in a 5G communication system, eMBB should be able to provide a peak data rate of 20 Gigabits per second (Gbps) in DL and a peak data rate of 10 Gbps in UL for one BS. In addition, the 5G communication system should be able to provide an increased user-perceived data rate of the terminal while providing the peak data rate. In order to meet such requirements, various transmission and receiving technologies, including further enhanced MIMO transmission technology, need to be improved in the 5G communication system. In addition, the LTE system transmits signals by using a maximum transmission bandwidth of 20 megahertz (MHz) in a frequency band of 2 gigahertz (GHz). In contrast, the 5G communication system transmits signals by using a frequency bandwidth wider than 20MHz in a frequency band of 3 to 6 GHz or higher, so the data rate requirements required by the 5G communication system can be met.

[0078] When the BS supports wide bandwidth frequency, the BWP technology that divides the entire carrier frequency band into multiple frequency bands and the BS can support each of the multiple frequency bands for each terminal becomes more important. That is, when the BS supports BWP and the terminal has low bandwidth capability, the BS can support a small frequency bandwidth to the terminal through BWP, and the frequency bandwidth can be reduced by changing the BWP, thereby reducing the energy consumption of the terminal. In addition, different frame structures can be supported for each of the multiple BWPs, and various services can be provided to a terminal by changing the BWP without delay. The BWP technology can be applied to a one-to-one control channel or data channel between a certain terminal and the BS. In addition, for control channels and data channels used to send common signals (e.g., synchronization signals (SS), physical broadcast channels (PBCH) or system information) to multiple terminals in the system, the BS can send control channels and data channels only in the configured BWP, thereby reducing the energy consumption of the BS.

[0079] In addition, mMTC is considered to support application services such as IoT in 5G communication systems. In order to effectively provide IoT, mMTC should support access to a large number of terminals in a cell, improved battery time, cost reduction of terminals, etc. Because IoT is attached to various sensors and various devices to provide communication functions, IoT should support a large number of terminals in a cell (for example, 1,000,000 terminals / km 2 ). In addition, because the terminal supporting mMTC may be located in a shadow area not covered by a cell, such as a basement of a building, the terminal requires a wider coverage than other services provided by the 5G communication system. The terminal supporting mMTC should be an inexpensive terminal, and because it is difficult to frequently replace the battery of the terminal, the terminal requires a very long battery life (e.g., 10 to 15 years).

[0080] URLLC is a cellular-based wireless communication service for mission-critical applications. For example, URLLC is used for remote control of robots or machines, industrial automation, unmanned aerial vehicles, remote healthcare, emergency alerts, etc. Therefore, the communication provided by URLLC should provide very low latency (ultra-low latency) and very high reliability (ultra-high reliability). For example, a URLLC-enabled service should meet an air interface latency of less than 0.5 milliseconds and have a 10 -5 Or lower packet error rate. Therefore, for services supporting URLLC, the 5G system should provide a transmission time interval (TTI) that is shorter than that of other services, as well as a design for wide resource allocation in the frequency band to ensure the reliability of the communication link.

[0081] Considering three services for a 5G communication system (hereinafter, used interchangeably with the 5G system), namely eMBB, URLLC, and mMTC, which can be multiplexed and transmitted in one system. In order to meet the different requirements of the services, different transmission and reception schemes and different transmission and reception parameters can be used between the services.

[0082] Figure 1 The time-frequency domain as the radio resource domain of a 5G system according to an embodiment is shown.

[0083] Reference Figure 1 , the horizontal axis represents the time domain, and the vertical axis represents the frequency domain. The basic resource unit in the time-frequency domain is a resource element (RE) 1-01, and can be defined by an OFDM symbol (or discrete Fourier transform spread OFDM (DFT-s-OFDM) symbol) 1-02 in the time axis and a subcarrier 1-03 in the frequency axis. In the frequency domain, (For example, 12) consecutive REs may constitute a resource block (RB) 1-04. In addition, in the time domain, Consecutive OFDM symbols may constitute a subframe 1-10.

[0084] Figure 2 The time slot structure considered in the 5G system according to an embodiment is shown.

[0085] Reference Figure 2 , showing the structure of a frame 2-00, a subframe 2-01, and time slots 2-02 and 2-03. One frame 2-00 may be defined as 10 ms. One subframe 2-01 may be defined as 1 ms, and therefore, one frame 2-00 may include a total of 10 subframes 2-01. In addition, one time slot 2-02 or 2-03 may be defined as 14 OFDM symbols (i.e., the number of symbols per time slot One subframe 2-01 may include one or more time slots 2-02 or 2-03, and the number of time slots 2-02 or 2-03 of each subframe 2-01 may be changed according to the subcarrier spacing configuration value μ (2-04 and 2-05).

[0086] Figure 2 It is shown that the subcarrier spacing configuration value μ is 0 (2-04) and the subcarrier configuration value μ is 1 (2-05). When μ=0 (2-04), one subframe 2-01 can include one time slot 2-02, and when μ=1 (2-05), one subframe 2-01 can include two time slots 2-03. That is, the number of time slots per subframe is The number of time slots per frame can be changed according to the subcarrier spacing configuration value μ. Can be changed accordingly. According to each subcarrier spacing configuration value μ and It can be defined as shown in Table 1.

[0087] Table 1

[0088]

[0089] A BWP configuration in a 5G communication system will now be described in detail with reference to the accompanying drawings.

[0090] Figure 3 A BWP configuration in a 5G communication system according to an embodiment is shown.

[0091] Reference Figure 3 , UE bandwidth 3-00 includes BWP#1 3-05 and BWP#2 3-10. The BS may configure one or more BWPs in the UE and may configure the following information for each BWP.

[0092] Table 2

[0093]

[0094] This disclosure is not limited to Figure 3 In addition to the configuration information, various parameters related to the BWP may be configured in the UE, as shown in Table 2. The BS may send information to the UE through higher layer signaling (e.g., radio resource control (RRC) signaling). At least one of the configured one or more BWPs may be activated. Whether the configured BWP is activated may be semi-statically sent from the BS to the UE through RRC signaling, or may be dynamically sent through DCI.

[0095] Before the RRC connection, the initial BWP for the initial connection may be configured for the UE through the master information block (MIB) from the BS. More specifically, the UE may receive configuration information of the search space and control region (e.g., CORESET) in which the physical DL control channel (PDCCH) may be transmitted through the MIB in the initial access phase in order to receive system information required for the initial access (e.g., remaining system information (RMSI) or system information block 1 (SIB1)). The identifier (ID) of the control region and search space configured through the MIB may be considered to be 0. The BS may notify the UE of configuration information such as frequency allocation information, time allocation information, and parameter set of control region #0 through the MIB. The BS may notify the UE of configuration information of the monitoring period and timing of control region #0, i.e., configuration information of search space #0, through the MIB. The UE may regard the frequency domain configured as control region #0 obtained from the MIB as the initial BWP for initial access. In this case, the ID of the initial BWP may be considered to be 0.

[0096] The configuration of BWP supported by the 5G system can be used for various purposes.

[0097] When the bandwidth supported by the UE is smaller than the system bandwidth, the BS can support the UE through BWP configuration. For example, the BS configures the frequency position of the BWP in the UE (configuration 2) so that the UE sends and receives data at a specific frequency position within the system bandwidth.

[0098] The BS may configure multiple BWPs in the UE to support different parameter sets. For example, in order to support data transmission to and reception from a certain UE using both a subcarrier spacing of 15 kHz and a subcarrier spacing of 30 kHz, the BS may configure two BWPs with subcarrier spacings of 15 kHz and 30 kHz. Different BWPs may be frequency-division multiplexed, and when data is to be transmitted and received at a specific subcarrier spacing, a BWP configured with a specific subcarrier spacing may be activated.

[0099] The BS can configure BWPs with different bandwidths in the UE in order to reduce the power consumption of the UE. For example, when the UE supports a very large bandwidth (for example, a bandwidth of 100 MHz) and always sends and receives data in this bandwidth, very high power consumption may occur. Specifically, when there is no business, monitoring unnecessary DL control channels by using a large bandwidth of 100 MHz may be very inefficient in terms of power consumption. In order to reduce the power consumption of the UE, the BS can configure a BWP with a relatively small bandwidth, such as a BWP of 20 MHz, for the UE. When there is no business, the UE can perform monitoring operations in a BWP of 20 MHz, and when data is generated, the UE can send and receive data in a BWP of 100 MHz according to instructions from the BS.

[0100] In the above-mentioned method for configuring BWP, before RRC connection, the UE can receive configuration information about the initial BWP through the MIB in the initial access phase. More specifically, the UE can be configured with a control region (e.g., CORESET) for a DL control channel from the MIB of the PBCH, in which the DCI for scheduling SIBs can be sent. The bandwidth of the control region configured by the MIB can be considered as the initial BWP, and the UE can receive a physical DL shared channel (PDSCH) through which the SIB is sent via the configured initial BWP. The initial BWP can be used for reception of other system information (OSI), paging and random access, and SIBs.

[0101] When one or more BWPs are configured in the UE, the BS can instruct the UE to change the BWP by using the BWP indicator field in the DCI. For example, when the currently activated BWP of the UE is Figure 3 When the BS indicates BWP#1 3-05 in the received DCI, the BS may indicate BWP#2 3-10 to the UE through the BWP indicator in the DCI, and the UE may change the BWP to BWP#2 3-10 indicated by the BWP indicator in the received DCI.

[0102] Because, as described above, the DCI-based BWP change can be indicated by the DCI for scheduling PDSCH or physical UL shared channel (PUSCH), when the UE receives the BWP change request, the UE should receive or send the PDSCH or PUSCH scheduled by the DCI in the changed BWP without difficulty. To this end, the delay time T required for the BWP change is specified in the standard. BWP requirements and can be defined as follows.

[0103] Table 3

[0104]

[0105] According to the capability of UE, the requirement for BWP change delay time supports type 1 and type 2. UE can report the supportable BWP delay time type to BS.

[0106] Figure 4 A method of changing bandwidth according to an embodiment is shown.

[0107] Reference Figure 4 According to the requirement for BWP change delay time, when the UE receives the DCI including the BWP change indicator in time slot n (4-15), the UE can change the BWP indicator no later than time slot n+T BWPThe BS can complete the change to the new BWP indicated by the BWP change indicator within a time period of 4-10, and can send and receive the data channel scheduled by the DCI in the new BWP 4-10. When the BS is to schedule the data channel to the new BWP, the BS can consider the BWP change delay time T of the UE. BWP 4-20 determines the time domain resource allocation of the data channel. That is, when the BS schedules the data channel to the new BWP, in the method of determining the time domain resource allocation of the data channel, the BS may schedule the data channel after the BWP change delay time (4-35 and 4-40). Therefore, the UE may not expect the DCI indicating the BWP change to be less than the BWP change delay time T. BWP The time slot offset of 4-20 is K0 or K2.

[0108] When the UE receives a DCI indicating a BWP change (e.g., DCI format 1_1 or 0_1), the UE may not perform any transmission or reception during the duration from the third symbol of the time slot in which the PDCCH including the DCI is received to the start point of the time slot indicated by the time slot offset K0 or K2 indicated by the time domain resource allocation indicator field in the DCI. For example, when the UE receives a DCI indicating a BWP change in time slot n, and the time slot offset value indicated in the DCI is K, the UE may not perform any transmission or reception during the duration from the third symbol of time slot n to the symbol before time slot n+K (i.e., the last symbol of time slot n+K-1).

[0109] The UE may be configured with one or more BWPs from the BS, and may be additionally configured with parameters for transmission and reception of each configured BWP (e.g., UL data channel and control channel related configuration information). Figure 3 When BWP#1 3-05 is activated, the UE may perform transmission and reception with the BS based on the transmission and reception parameter #1, and when BWP#2 3-10 is activated, the UE may perform transmission and reception with the BS based on the transmission and reception parameter #2.

[0110] More specifically, the following parameters may be configured in the UE from the BS.

[0111] First, the following information may be configured for the UL BWP.

[0112] Table 4

[0113]

[0114] According to Table 4, the UE can be configured with cell-specific (or cell-common or common) transmission-related parameters (e.g., random access channel (RACH), UL control channel (physical UL control channel (PUCCH), and UL data channel (PUSCH) related parameters) from the BS (corresponding to BWP-UplinkCommon). The UE can be configured with UE-specific (or dedicated) transmission-related parameters (e.g., PUCCH, PUSCH, ungranted UL transmission (configured granted PUSCH), and SRS-related parameters) from the BS (corresponding to BWP-UplinkDedicated).

[0115] For DL ​​BWP, the following information can be configured.

[0116] Table 5

[0117]

[0118] According to Table 5, the UE can be configured with cell-specific (or cell-common or common) reception-related parameters (e.g., DL control channels such as PDCCH and DL data channels such as PDSCH) related parameters) from the BS (corresponding to BWP-DownlinkCommon). The UE can be configured with UE-specific (or dedicated) reception-related parameters (e.g., PDCCH, PDSCH, DL data transmission based on unauthorized transmission (semi-persistently scheduled PDSCH), and radio link monitoring (RLM) related parameters) from the BS (corresponding to BWP-UplinkDedicated).

[0119] Figure 5 A CORESET is shown in which a DL control channel is transmitted according to an embodiment.

[0120] refer to Figure 5 , the UE BWP 5-10 is configured in the frequency axis, and two control resource sets (control resource set #1 5-01 and control resource set #2 5-02) are configured in one time slot 5-20 in the time axis. The control resource sets 5-01 and 5-02 may be configured in a specific frequency resource 503 within the entire UE BWP 5-10 along the frequency axis. The control resource sets 5-01 and 5-02 may be configured with one or more OFDM symbols along the time axis and may be defined by a control resource set duration 5-04. The control resource set #1 5-01 may be configured with a control resource set duration of two symbols, and the control resource set #2 5-02 may be configured with a control resource set duration of one symbol.

[0121] In the 5G system, the BS can configure each control resource set in the UE through higher layer signaling (e.g., system information, MIB, or RRC signaling). When a control resource set is configured in the UE, this means that information such as a control resource set ID, a frequency position of the control resource set, and a symbol length of the control resource set is provided to the UE. For example, the information provided for configuring a control resource set is as follows.

[0122] Table 6

[0123]

[0124] The control resource set in the 5G system may include NRBCORESET RBs in the frequency domain and may include NsymbCORESET∈{1,2,3} symbols in the time axis. A control channel element (CCE) may include 6 resource element groups (REGs), and each REG may be defined as an RB during an OFDM symbol. The REGs in a control resource set may be numbered in a time-first manner, starting from 0 for the first OFDM symbol and the lowest numbered RB in the control resource set.

[0125] In the 5G system, the interleaving method and the non-interleaving method are supported as methods for transmitting PDCCH. The BS can configure in the UE through higher layer signaling whether to perform interleaving transmission or non-interleaving transmission for each control resource set. Interleaving can be performed in units of REG bundles. The term "REG bundle" can be defined as a set of one or more REGs. The UE can determine the CCE to REG mapping method in the control resource set by using the following method based on whether to perform interleaving or non-interleaving transmission configured from the BS.

[0126] Table 7

[0127]

[0128] The basic unit (ie, REG) of the DL control channel may include an RE to which the DCI is mapped and an area to which a demodulation reference signal (DMRS) (which is a reference signal (RS) for decoding RE) is mapped. One REG may include three DMRS REs. Depending on the aggregation level (AL), the number of CCEs required to send a PDCCH may be 1, 2, 4, 8, or 16, and different numbers of CCEs may be used to implement link adaptation of the DL control channel. For example, when AL=L, one DL control channel may be sent via L CCEs.

[0129] The UE should detect the signal without knowing information about the DL control channel and may define a search space indicating a set of CCEs for blind decoding. The search space may be a set of DL control channel candidates including CCEs that the UE should attempt to decode at a given AL. Because there are various ALs for bundling up 1, 2, 4, 8, or 16 CCEs, the UE may have multiple search spaces. A search space set may be defined as the set of search spaces at all configured ALs.

[0130] The search space can be classified into a common search space and a UE-specific search space. A group of UEs or all UEs can investigate the common search space of the PDCCH in order to receive cell common control information, such as paging messages or dynamic scheduling of system information. For example, the UE can receive PDSCH scheduling allocation information for SIB transmission including cell service provider information, etc. by investigating the common search space of the PDCCH. Because a certain group of UEs or all UEs should receive the PDCCH, the common search space can be defined as a set of previously agreed CCEs. The UE can receive scheduling allocation information for UE-specific PDSCH or PUSCH by investigating the UE-specific search space of the PDCCH. The UE-specific search space can be specifically defined for the UE as a function of various system parameters and UE identification.

[0131] In the 5G system, the parameters of the search space of the PDCCH can be configured in the UE by the BS through higher layer signaling (e.g., SIB, MIB or RRC signaling). For example, the BS can configure the number of PDCCH candidates at each ALL, the monitoring period of the search space, the monitoring timing of the symbol unit within the time slot of the search space, the search space type (i.e., common search space or UE-specific search space), the combination of the radio network temporary identifier (RNTI) and the DCI format to be monitored in the search space, and the index of the control resource set used to monitor the search space in the UE. For example, the parameters of the search space of the PDCCH may include the following information.

[0132] Table 8

[0133]

[0134] The BS may configure one or more search space sets in the UE. The BS may configure search space set 1 and search space set 2 in the UE. In search space set 1, DCI format A scrambled by X-RNTI may be configured to be monitored by the UE in a common search space, and in search space set 2, DCI format B scrambled by Y-RNTI may be configured to be monitored by the UE in a UE-specific search space.

[0135] According to the configuration information, one or more search space sets may exist in a common search space or a UE-specific search space. For example, search space set #1 and search space set #2 may be configured in a common search space, and search space set #3 and search space set #4 may be configured in a UE-specific search space.

[0136] In the common search space, the following combinations of DCI formats and RNTIs may be monitored. However, the present disclosure is not limited to the following embodiments.

[0137] - DCI format 0_0 / 1_0 with cyclic redundancy check (CRC) scrambled by: Cell RNTI (C-RNTI), Configured Scheduling RNTI (CS-RNTI), Semi-Persistent Channel State Information RNTI (SP-CSI-RNTI), Random Access RNTI (RA-RNTI), Temporary Cell RNTI (TC-RNTI), Paging RNTI (P-RNTI), System Information RNTI (SI-RNTI)

[0138] - DCI format 2_0 with CRC scrambled by slot format indicator RNTI (SFI-RNTI)

[0139] -DCI format 2_1 with CRC scrambled by interrupt RNTI (INT-RNTI)

[0140] -DCI format 2_2 with CRC scrambled by transmit power control of PUSCH RNTI (TPC-PUSCH-RNTI), TPC of PUCCH RNTI (TPC-PUCCH-RNTI)

[0141] -DCI format 2_3 with CRC scrambled by TPC of SRS RNTI (TPC-SRS-RNTI)

[0142] In the UE-specific search space, the following combinations of DCI formats and RNTIs may be monitored. However, the present disclosure is not limited to the following embodiments.

[0143] - DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0144] - The RNTI specified by DCI format 1_0 / 1_1 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI may conform to the following definitions and usages.

[0145] C-RNTI: used to schedule UE-specific PDSCH

[0146] TC-RNTI: used to schedule UE-specific PDSCH

[0147] CS-RNTI: used to schedule UE-specific PDSCH with semi-static configuration

[0148] RA-RNTI: used to schedule PDSCH during random access phase

[0149] P-RNTI: used to schedule PDSCH for sending paging

[0150] SI-RNTI: used to schedule PDSCH for sending system information

[0151] INT-RNTI: used to notify whether PDSCH is punctured

[0152] TPC-PUSCH-RNTI: used to indicate the power control command of PUSCH

[0153] TPC-PUCCH-RNTI: used to indicate the power control command of PUCCH

[0154] TPC-SRS-RNTI: used to indicate the power control command of SRS

[0155] The above DCI format may conform to the following definition.

[0156] Table 9

[0157] DCI format use 0_0 Scheduling PUSCH in a cell 0_1 Scheduling PDSCH in a cell 1_0 Scheduling PUSCH in a cell 1_1 Scheduling PDSCH in a cell 2_0 Notify a group of UEs of the timeslot format 2_1 Notify a group of UEs of the PRB(s) and OFDM symbol(s) in which the UE may assume no transmission for the UE 2_2 Transmission of TPC commands for PUCCH and PUSCH 2_3 A set of TPC commands for SRS transmission is sent by one or more UEs

[0158] For example, the BS may schedule the PUSCH in one cell using DCI format 0_0 or DCI format 0_1.

[0159] When transmitted together with a CRC scrambled by at least one of a C-RNTI, a CS-RNTI, or a modulation and coding scheme cell RNTI (MCS-C-RNTI), DCI format 0_0 includes at least the following information.

[0160] -DCI format ID (1 bit): DCI format indicator, always set to 0

[0161] - Frequency domain resource allocation (payload is determined according to frequency domain resource allocation): indicates frequency domain resource allocation, is the size of the active UL BWP.

[0162] - Time domain resource allocation (4 bits): indicates time domain resource allocation.

[0163] - Frequency hopping flag (1 bit): indicates whether to perform frequency hopping of the PUSCH allocated by the DCI.

[0164] - Modulation and coding scheme (5 bits): Indicates the modulation order and coding rate used for PUSCH transmission.

[0165] - New data indicator (1 bit): Indicates whether the PUSCH corresponds to initial transmission or retransmission depending on toggling.

[0166] - Redundancy version (2 bits): indicates the redundancy version used for PUSCH transmission.

[0167] - Hybrid Automatic Repeat Request (HARQ) process number (4 bits): indicates the HARQ process number used for PUSCH transmission.

[0168] -Scheduled PUSCH transmit power control (TPC) command (2 bits): PUSCH power control indicator.

[0169] -UL / Supplementary UL (SUL) indicator (1 bit): indicates whether the SUL of the PUSCH allocated by the DCI is transmitted. When transmission using the SUL is not performed, the bit length of the corresponding field is 0 bits.

[0170] When transmitted together with a CRC scrambled by at least one of C-RNTI, CS-RNTI, SP-CSI-RNTI, or MCS-C-RNTI, DCI format 0_1 ​​includes at least the following information.

[0171] -DCI format ID (1 bit): DCI format indicator, set to 0

[0172] - Carrier indicator (0 or 3 bits): Indicates the component carrier (CC) (or cell) on which the PUSCH assigned by the DCI is transmitted.

[0173] -UL / SUL indicator (0 or 1 bit): indicates whether the SUL of the PUSCH allocated by the DCI is transmitted.

[0174] -BWP (0, 1 or 2 bits): indicates the BWP for transmitting the PUSCH allocated by DCI.

[0175] Frequency domain resource allocation (payload is determined based on frequency domain resource allocation): indicates frequency domain resource allocation, is the size of the active DL BWP.

[0176] - Time domain resource allocation (0, 1, 2, 3 or 4 bits): indicates the time domain resource allocation.

[0177] - Frequency hopping flag (0 or 1 bit): indicates whether to perform frequency hopping of the PUSCH allocated by the DCI.

[0178] - Modulation and coding scheme (5 bits): Indicates the modulation order and coding rate used for PUSCH transmission.

[0179] - New data indicator (1 bit): Indicates whether the PUSCH corresponds to initial transmission or retransmission depending on toggling.

[0180] - Redundancy version (2 bits): indicates the redundancy version used for PUSCH transmission.

[0181] -HARQ process number (4 bits): indicates the HARQ process number used for PUSCH transmission.

[0182] - First DL assignment index (DAI) (1 or 2 bits): indicates the DAI used for HARQ acknowledgement (ACK) codebook generation.

[0183] - Second DL assignment index (0 or 2 bits): indicates the DAI used for HARQ-ACK codebook generation.

[0184] - TPC command for scheduled PUSCH (2 bits): PUSCH TPC indicator assigned by DCI.

[0185] - SRS resource indicator (changed according to SRS usage configuration): indicates the transmission precoding configuration of the PUSCH allocated by the DCI through the SRS resource.

[0186] - Precoding information and number of layers (0, 1, 2, 3, 4, 5 or 6 bits): indicates the transmission precoding information and the number of transmission layers of the PUSCH allocated by the DCI.

[0187] - Antenna port (2, 3, 4 or 5 bits): Indicates the transmission DMRS port of the PUSCH allocated by DCI and the code division multiplexing (CDM) group without data.

[0188] - SRS request (2 or 3 bits): indicates a request for SRS resources to be transmitted through DCI.

[0189] - Channel State Information (CSI) Request (0, 1, 2, 3, 4, 5 or 6 bits): indicates the CSI report triggering status requested to be sent via DCI.

[0190] -Code block group (CBG) transmission information (0, 2, 4, 6 or 8 bits): an indicator indicating whether a code block group in a PUSCH allocated by DCI is transmitted.

[0191] - Phase Tracking Reference Signal (PTRS)-DMRS association (0 or 2 bits): indicates the association between the PTRS port and the DMRS port of the PUSCH allocated by the DCI.

[0192] - Beta_offset indicator (0 or 2 bits): Indicates the offset value used when HARQ-ACK or CSI report is multiplexed to PUSCH.

[0193] -DMRS sequence initialization (0 or 1 bit): DMRS scrambling ID selection indicator.

[0194] -UL Shared Channel (SCH) indicator (0 or 1 bit): indicates whether UL-SCH is included in the PUSCH allocated by DCI.

[0195] For example, the BS may use DCI format 1_0 or DCI format 1_1 to schedule a PDSCH in one cell.

[0196] When transmitted together with a CRC scrambled by C-RNTI, CS-RNTI, or MCS-C-RNTI, DCI format 1_0 includes at least the following information.

[0197] -DCI format ID (1 bit): DCI format indicator, set to 1

[0198] - Frequency domain resource allocation bit): indicates frequency domain resource allocation, and when monitoring DCI format 1_0 in the UE-specific search space, is the size of the active DL BWP, otherwise, is the size of the initial DL BWP. The detailed method is described in the above frequency domain resource allocation.

[0199] When all values ​​of the frequency domain resource assignment field are set to 1, DCI format 1_0 indicates a command for a random access procedure, and all remaining fields are configured as follows.

[0200] - Random access preamble index (6 bits): indicates the index of a preamble used to perform random access.

[0201] -UL / SUL indicator (1 bit): When all values ​​of the Random Access Preamble Index field are not all set to 0 and the UE is configured with supplementaryUplink in the higher layer parameter ServingCellConfig, this field indicates the UL carrier used to send the physical RACH (PRACH).

[0202] -SS / PBCH Index (6 bits): When all values ​​of the Random Access Preamble Index field are not all set to 0, this field indicates the SS / PBCH used for PRACH transmission.

[0203] -PRACH Mask Index (4 bits): When all values ​​of the Random Access Preamble Index field are not all set to 0, this field indicates the RACH duration associated with the SS / PBCH indicated by the SS / PBCH Index.

[0204] When all bits of the frequency domain resource assignment field are not all set to 1, the remaining fields are configured as follows.

[0205] - Time domain resource allocation (4 bits): indicates the time domain resource allocation according to the above description.

[0206] - Virtual RB (VRB) to physical RB (PRB) mapping (1 bit): 0 indicates non-interleaved VRB to PRB mapping, 1 indicates interleaved VRB to PRB mapping.

[0207] - Modulation and coding scheme (5 bits): Indicates the modulation order and coding rate used for PDSCH transmission.

[0208] - New data indicator (1 bit): indicates whether the PDSCH corresponds to initial transmission or retransmission according to toggling.

[0209] - Redundancy version (2 bits): indicates the redundancy version used for PDSCH transmission.

[0210] -HARQ process number (4 bits): indicates the HARQ process number used for PDSCH transmission.

[0211] -DL Allocation Index (2 bits): DAI indicator

[0212] - TPC command for scheduled PUCCH (2 bits): PUCCH power control indicator

[0213] - PUCCH resource indicator (3 bits): PUCCH resource indicator, which indicates one of eight resources configured via higher layers.

[0214] - PDSCH-to-HARQ_feedback timing indicator (3 bits): HARQ feedback timing indicator, which indicates one of eight feedback timing offsets configured by higher layers.

[0215] When transmitted together with a CRC scrambled by C-RNTI, CS-RNTI or MCS-C-RNTI, DCI format 1_1 includes the following information.

[0216] -DCI format ID (1 bit): DCI format indicator, always set to 1

[0217] - Carrier indicator (0 or 3 bits): indicates the CC (or cell) that transmits the PDSCH assigned by the DCI.

[0218] - BWP indicator (0, 1 or 2 bits): indicates the BWP for transmitting the PDSCH allocated by the DCI.

[0219] - Frequency domain resource allocation (payload is determined according to frequency domain resource allocation): indicates frequency domain resource allocation, - is the size of the active DL BWP. The detailed method is described in the above frequency domain resource allocation.

[0220] - Time domain resource allocation (0, 1, 2, 3 or 4 bits): indicates the time domain resource allocation according to the above description.

[0221] - VRB to PRB mapping (0 or 1 bit): 0 indicates non-interleaved VRB to PRB mapping, 1 indicates interleaved VRB to PRB mapping. When frequency domain resource allocation is configured as resource type 0, the information is 0 bits.

[0222] -PRB bundle size indicator (0 or 1 bit): 0 bit when the higher layer parameter prb-BundlingType is not configured or set to "static", 1 bit when the higher layer parameter is set to "dynamic".

[0223] - Rate matching indicator (0, 1 or 2 bits): Indicates the rate matching mode.

[0224] - Zero Power (ZP) CSI-RS Trigger (0, 1 or 2 bits): an indicator to trigger AP ZP CSI-RS.

[0225] -For transport block 1:

[0226] - Modulation and coding scheme (5 bits): Indicates the modulation order and coding rate used for PDSCH transmission.

[0227] - New data indicator (1 bit): indicates whether the PDSCH corresponds to initial transmission or retransmission according to toggling.

[0228] - Redundancy version (2 bits): indicates the redundancy version used for PDSCH transmission.

[0229] -For transport block 2:

[0230] - Modulation and coding scheme (5 bits): Indicates the modulation order and coding rate used for PDSCH transmission.

[0231] - New data indicator (1 bit): indicates whether the PDSCH corresponds to initial transmission or retransmission according to toggling.

[0232] - Redundancy version (2 bits): indicates the redundancy version used for PDSCH transmission.

[0233] -HARQ process number (4 bits): indicates the HARQ process number used for PDSCH transmission.

[0234] -DL Allocation Index (0, 2 or 4 bits): DAI indicator

[0235] -TPC command for scheduling PUCCH (2 bits): PUCCH power control indicator

[0236] - PUCCH resource indicator (3 bits): PUCCH resource indicator, which indicates one of eight resources configured via higher layers.

[0237] - PDSCH-to-HARQ_feedback timing indicator (0, 1, 2 or 3 bits): HARQ feedback timing indicator, which indicates one of eight feedback timing offsets configured by higher layers.

[0238] - Antenna port (4, 5 or 6 bits): Indicates the DMRS port and CDM group with no data.

[0239] - Transmission Configuration Indication (TCI) (0 or 3 bits): TCI indicator.

[0240] - SRS request (2 or 3 bits): SRS transmission request indicator.

[0241] -CBG transmission information (0, 2, 4, 6 or 8 bits): an indicator indicating whether the code block group in the allocated PDSCH is transmitted. 0 indicates that the CBG is not transmitted, and 1 indicates that the CBG is transmitted.

[0242] -CBG clearing information (0 or 1 bit): an indicator indicating whether the previous CBG is contaminated, 0 indicates that the CBG may be contaminated, and 1 indicates that the CBG can be combined in the retransmission reception.

[0243] -DMRS sequence initialization (1 bit): DMRS scrambling ID selection indicator

[0244] For example, the BS may use DCI format 2_3 to send a TPC command group for SRS transmission to one or more UEs.

[0245] When sent together with a CRC scrambled by TPC-SRS-RNTI, DCI format 2_3 includes the following information.

[0246] - Block 1, Block 2, ... Block B: The starting position of the block is indicated by using the higher layer parameter startingBitOfFormat2-3 or startingBitOfFormat2-3 SUL-v1530.

[0247] When the UE is configured as type A without PUCCH and PUSCH by higher layer parameter srs-TPC-PDCCH-Group set, or for UL on which SRS power control is not linked with PUSCH power control, one block is configured for the UE via higher layers with the following fields:

[0248] - SRS request (0 or 2 bits): When this field exists as a field for notifying an SRS request, it indicates an AP SRS resource set to be triggered.

[0249] -TPC command No. 1, TPC command No. 2, ..., TPC command No. N: TPC command applied to each UL carrier

[0250] When the UE is set to Type B by higher layer parameter srs-TPC-PDCCH-Group without PUCCH or PUSCH, or for UL on which SRS power control is not linked with PUSCH power control, one or more blocks are configured for the UE via higher layers, each block applies to the UL carrier together with the following fields:

[0251] - SRS request (0 or 2 bits): When this field exists as a field for notifying an SRS request, this field indicates an AP SRS resource set to be triggered.

[0252] -TPC command (2 bits): TPC command sent by SRS

[0253] The number of pieces of DCI with different sizes that the UE can receive in each time slot in the cell is up to 4. The number of pieces of DCI with different sizes scrambled by the C-RNTI that the UE can receive in each time slot in the cell is up to 3.

[0254] In the 5G system, the search space of AL L in the control resource set p and the search space set s can be expressed as equation (1).

[0255]

[0256] -L: aggregation level

[0257] -n CI : Carrier index

[0258] -N CCE，p : The total number of CCEs in control resource set p

[0259] - Time slot index

[0260] - Number of PDCCH candidates at aggregation level L

[0261] - Index of PDCCH candidates at aggregation level L

[0262] -i=0,...,L-1

[0263] -,,,,,

[0264] -nRNTI: UE ID (1)

[0265] Can be 0 in the common search space.

[0266] In the UE-specific search space, It may be changed according to the UE's identity (C-RNTI or ID configured by the BS for the UE) and the time index.

[0267] A method of configuring a TCI state, which is a means for indicating or exchanging quasi co-location (QCL) information between a UE and a BS in a 5G communication system, will now be described in detail.

[0268] The BS can configure and indicate the TCI state between two different RSs or channels through appropriate signaling to notify the QCL relationship between different RSs or channels. When different RSs or channels are quasi-co-located, when the channel is estimated by the reference RS antenna port A (reference RS#A) and the target RS antenna port B (target RS#B) in a QCL relationship, the UE is allowed to apply some or all of the large-scale channel parameters estimated in antenna port A to perform channel measurements from antenna port B. QCL may require different parameters to be associated with each other depending on the following situations including: 1) time tracking affected by average delay and delay spread, 2) frequency tracking affected by Doppler shift and Doppler spread, 3) radio resource management (RRM) affected by average gain, and 4) beam management (BM) affected by spatial parameters. Accordingly, NR supports four types of QCL relationships, as shown in Table 10.

[0269] Table 10

[0270] QCL Type Large-scale features A Doppler shift, Doppler spread, average delay, delay spread B Doppler shift, Doppler spread C Doppler shift, average delay D Space Rx parameters

[0271] Spatial Rx parameters may be a general term for all or some of the various parameters, including angle of arrival (AoA), power angular spectrum (PAS) of AoA, angle of departure (AoD), PAS of AoD, transmit / receive channel correlation, transmit / receive beamforming, and spatial channel correlation.

[0272] As shown in Table 11, the QCL relationship can be configured in the UE through the RRC parameters TCI-State and QCL-Info.

[0273] Referring to Table 11, the BS may configure at least one TCI state in the UE to notify the UE of up to two QCL relationships (e.g., qcl-Type1 and qcl-Type2) associated with the RS (i.e., target RS) of the ID indicating the TCI state. In this case, each QCL information (QCL-Info) included in each TCI state includes a serving cell index and a BWP index of the reference RS indicated by the QCL information, a type and ID of the reference RS, and a QCL type, as shown in Table 10.

[0274] Table 11

[0275]

[0276] A method of configuring spatial relationship information SpatialRelationInfo, which is a means for indicating UL beam information between a UE and a BS in a 5G communication system, will now be described in detail.

[0277] The BS can configure a relationship with another DL channel or signal or UL channel or signal B (information referenceSignal included in the spatial relationship information SpatialRelationInfo) in UL channel or signal A (channel or signal of reference spatial relationship information SpatialRelationInfo) through appropriate signaling. The UE transmits channel or signal A using the beam direction for reception or transmission of channel or signal B based on the relationship.

[0278] The configuration of the spatial relationship information SpatialRelationInfo may vary according to the type of UL channel or signal that references the spatial relationship information SpatialRelationInfo. For example, the SpatialRelationInfo referenced by the SRS resource may include information referenceSignal for determining the PUCCH transmission beam, as shown in Table 12.

[0279] Table 12

[0280]

[0281] Although the TCI state is used to indicate the beam of the DL channel (the UE's receiving spatial filter value / type), and the SpatialRelationInfo is used to indicate the beam of the UL channel (the UE's transmitting spatial filter value / type), this does not mean that there is a limitation according to the UL / DL type, and mutual extension may be possible. For example, by adding a UL channel or signal to the type of target RS that can refer to the TCI state, or adding a UL channel or signal to the type of referenceSignal (reference RS) included in the TCI state or QCL-Info, the traditional DL TCI state can be extended to the UL TCI state. Although there are various other extension methods, such as a DL-UL joint TCI state, in order not to confuse the main points of the present disclosure, not all methods will be described.

[0282] The BS may configure configuration information for transmitting a UL reference signal in the UE. Although SRS or AP SRS is described as a UL reference signal, this is merely an example of a UL reference signal and the present disclosure is not limited thereto. The BS may configure at least one SRS configuration for each UL BWP to transmit configuration information for SRS transmission, and may also configure at least one SRS resource set for each SRS configuration. For example, the BS and the UE may transmit and receive signaling information as follows to transmit information on an SRS resource set (according to an example of Release 15).

[0283] Table 13

[0284]

[0285] srs-Config may be used to configure SRS transmission to define an SRS resource list and an SRS resource set list, and to send and receive signaling information as follows.

[0286] Table 14

[0287]

[0288]

[0289]

[0290] resourceType: The time domain transmission configuration of the SRS resource referenced by the SRS resource set, which may have one of "periodic", "semi-persistent", and "AP". When the time domain transmission configuration is set to "periodic" or "semi-persistent", the associated CSI-RS information may be provided according to the purpose of the SRS resource set. When the time domain transmission configuration is set to "AP", the AP SRS resource trigger list and time slot offset information may be provided, and the associated CSI-RS information may be provided according to the purpose of the SRS resource set.

[0291] usage: Configuration of the usage of the SRS resource referenced by the SRS resource set, which may be one of "beamManagement", "codebook", "nonCodebook" and "antennaSwitching".

[0292] alpha, p0, pathlossReferenceRS, srs-PowerControlAdjustmentStates: provides parameter configuration for transmit power control of the SRS resources referenced by the SRS resource set.

[0293] The UE may recognize that the SRS resources included in the set of SRS resource indexes referenced by the SRS resource set follow the information configured in the SRS resource set.

[0294] The BS and the UE may send and receive higher layer signaling information to send separate configuration information for SRS resources. For example, the separate configuration information for SRS resources may include time-frequency domain mapping information in the time slot of the SRS resources, and the time-frequency domain mapping information may include information about frequency hopping within or between time slots of the SRS resources. Alternatively, the separate configuration information for SRS resources may include a time domain transmission configuration for the SRS resources, and may have one of "periodic", "semi-persistent" and "AP". Accordingly, it may be possible to restrict to have a time domain transmission configuration such as an SRS resource set including SRS resources. When the time domain transmission configuration of the SRS resources is set to "periodic" or "semi-persistent", the SRS resource transmission period and time slot offset (e.g., periodicityAndOffset) may be additionally included. Alternatively, the separate configuration information for the SRS resources may include the configuration of the spatial domain transmission filter of the UE that transmits the SRS resources, and the configuration may be provided by the spatial relationship information of the SRS. When the spatial relationship information included in the separate configuration information of the SRS resource refers to the index of the synchronization signal block (SSB) or CSI-RS resource, the UE can recognize that the same spatial domain transmit filter as the spatial domain receive filter used to receive the SSB or CSI-RS resource is used. Alternatively, when the spatial relationship information refers to another SRS resource index, the UE can recognize that the spatial domain transmit filter used to transmit the referenced SRS resource is used.

[0295] The UE may be configured with one or more SRS resource sets configured by a higher layer parameter SRS-ResourceSet. For each SRS resource set, the UE may be configured with K (K ≥ 1) SRS resources. In this case, the maximum value K is determined by the UE capability, except that the maximum value K is set to 16 by the higher layer parameter [SRS-for-positioning]. The applicability of the SRS resource set is configured according to the "usage" in the higher layer parameter SRS-ResourceSet. When the higher layer parameter "usage" is set to "beamManagement", only one SRS resource in each of multiple SRS sets can be sent at a given moment, but SRS resources in different SRS resource sets with the same time domain behavior in the same BWP can be sent simultaneously.

[0296] For AP SRS, at least one state of the DCI field is used to select at least one of the configured SRS resource sets.

[0297] The following SRS parameters may be semi-statically configured by a higher layer parameter SRS-Resource.

[0298] -srs-ResourceId determines the SRS resource configuration ID.

[0299] Number of SRS ports - Can be configured by the higher layer parameter nrofSRS-Ports and can be set to 1, 2 or 4. When nrofSRS-Ports is not configured, nrofSRS-Ports is 1.

[0300] - The time domain behavior of the SRS resource configuration indicated by the higher layer parameter resourceType can be one of periodic, semi-persistent and AP SRS transmission.

[0301] -When the SRS resource type is periodic or semi-persistent, the slot level periodicity and slot level offset are determined by the higher layer parameter periodicityAndOffset-p or periodicityAndOffset-sp. The UE does not expect to be configured with SRS resources with different slot level periodicities in the same SRS resource set SRS-ResourceSet. When the higher layer parameter resourceType of SRS-ResourceSet is set to 'AP', the slot level offset is defined by the higher layer parameter slotOffset.

[0302] - The number of OFDM symbols of the SRS resource, the starting OFDM symbol in the slot and the repetition factor R are configured by the higher layer parameter resourceMapping. When the repetition factor R is not configured, the repetition factor R is the same as the number of OFDM symbols in the SRS resource.

[0303] - The SRS bandwidth B_SRS and C_SRS are configured by the higher layer parameter freqHopping. When not configured, the SRS bandwidth B_SRS is 0.

[0304] -The frequency hopping bandwidth b_hop is configured by the high-level parameter freqHopping. If not configured, the frequency hopping bandwidth b_hop is 0.

[0305] - The frequency domain position and configurable offset are configured by the higher layer parameters freqDomainPosition and freqDomainShift respectively. When not configured, the higher layer parameter freqDomainPosition is 0.

[0306] - For transmit comb values ​​2, 4 and 8, the cyclic shift is configured by each of the higher layer parameters cyclicShift-n2, cyclicShift-n4 and cyclicShift-n8.

[0307] - The transmission comb value is configured by the higher layer parameter transmissionComb.

[0308] - For transmit comb values ​​2, 3 and 8, the transmit comb offset is configured by higher layer parameters combOffset-n2, combOffset-n4 or combOffset-n8.

[0309] The SRS sequence ID is configured by the higher layer parameter sequenceID.

[0310] The spatial relationship configuration between the reference RS and the target SRS can be configured by a higher-layer parameter spatialRelationInfo including the ID of the reference RS. The reference RS can be a SS / PBCH block, a CSI-RS configured on the same serving cell as the target SRS indicated by the higher-layer parameter servingCellId, or an SRS configured on the same serving cell as the target SRS indicated by the higher-layer parameter servingCellId, and a UL BWP indicated by the higher-layer parameter uplinkBWP. When the SRS is configured by a higher-layer parameter [SRS-for-positioning], the reference RS can also be a DL positioning reference signal (PRS) configured on the serving cell, a SS / PBCH block, or a DL PRS of a non-serving cell indicated by a higher-layer parameter.

[0311] The UE can be configured with N occupancy within the last 6 symbols of the time slot through the higher layer parameter resourceMapping in SRS-Resource. S ∈{1, 2, 4} adjacent symbols of the SRS resource. The symbols of the resource are mapped to all SRS antenna ports. When SRS is configured via the higher layer parameter [SRS-for-positioning], the UE can be configured with N occupancy anywhere in the time slot via the higher layer parameter resourceMapping in SRS-Resource. S ∈{1, 2, 4, 8, 12} SRS resources of adjacent symbols.

[0312] When the UE is not configured with [intraUEPrioritization] and PUSCH and SRS are transmitted in the same timeslot on the serving cell, the UE is configured to transmit SRS after transmitting PUSCH and the corresponding DMRS.

[0313] When a UE is configured by [intraUEPrioritization] and PUSCH transmission and SRS transmission overlap in time, the UE does not transmit SRS in the overlapping symbol(s).

[0314] When the UE is configured with one or more SRS resources and the higher-layer parameter resourceType in SRS-Resource is set to "periodic", the following operations are performed:

[0315] -When the UE is configured by a higher layer parameter spatialRelationInfo including an ID referring to "ssb-Index", the UE uses the same spatial domain transmit filter as the spatial domain transmit filter used to receive the reference SS / PBCH block to transmit the target SRS resource. When the UE is configured by a higher layer parameter spatialRelationInfo including an ID referring to "csi-RS-Index", the UE uses the same spatial domain transmit filter as the spatial domain transmit filter used to receive the reference periodic CSI-RS or the reference semi-persistent CSI-RS to transmit the target SRS resource. When the UE is configured by a higher layer parameter spatialRelationInfo including an ID referring to "srs", the UE uses the same spatial domain transmit filter as the spatial domain transmit filter used to transmit the reference periodic SRS to transmit the target SRS resource. When SRS is configured by a higher layer parameter [SRS-for-positioning] and the UE is configured by a higher layer parameter spatialRelationInfo including an ID referring to "DL-PRS-ResourceId", the UE transmits the target SRS resource using the same spatial domain transmit filter as that used to receive the reference DL PRS.

[0316] When the UE is configured with one or more SRS resource configurations and the higher layer parameter resourceType in SRS-Resource is set to "semi-persistent", the following operations are performed:

[0317] When the UE receives an activation command for an SRS resource and the UE sends a PUCCH with HARQ-ACK information corresponding to the PDSCH carrying the activation command in time slot n, Starting with the first time slot after the time slot, the corresponding actions and UE assumptions are applied on the SRS transmission corresponding to the configured SRS resource set. μ is the subcarrier configuration of the PUCCH. The activation command also includes a spatial relationship assumption provided by a reference list of reference signal IDs, one for each element of the activated SRS resource set. Each ID in the list refers to a reference SS / PBCH block, a non-ZP (NZP) CSI-RS resource configured on the serving cell indicated by the Resource Serving Cell ID field in the activation command (when there is the same serving cell as the SRS resource set), or (when there is the same serving cell and the same BWP as the SRS resource set) an SRS resource configured on the serving cell and UL BWP indicated by the Resource Serving Cell ID field and the Resource BWP ID field in the activation command. When SRS is configured by a higher layer parameter [SRS-for-positioning], each ID in the reference signal ID list may refer to a reference SS / PBCH block of a non-serving cell indicated by the higher layer parameter or a DL PRS of a serving or non-serving cell.

[0318] - When the SRS resources in the activated resource set are configured by a higher layer parameter spatialRelationInfo, the UE assumes that the ID of the reference signal in the activation command overrides the ID of the reference signal configured in spatialRelationInfo.

[0319] When the UE receives a deactivation command for an activated SRS resource set and sends a PUCCH with HARQ-ACK information corresponding to the PDSCH carrying the deactivation command in time slot n, Starting from the first time slot thereafter, the corresponding actions and UE assumptions regarding stopping SRS transmission corresponding to the deactivated SRS resource set apply. μ is the subcarrier configuration of the PUCCH.

[0320] -When the UE is configured by a higher layer parameter spatialRelationInfo including an ID referring to "ssb-Index", the UE uses the same spatial domain transmit filter as the spatial domain transmit filter used to receive the reference SS / PBCH block to transmit the target SRS resource. When the higher layer parameter spatialRelationInfo includes an ID referring to "csi-RS-Index", the UE uses the same spatial domain transmit filter as the spatial domain transmit filter used to receive the reference periodic CSI-RS or the reference semi-persistent CSI-RS to transmit the target SRS resource. When the higher layer parameter spatialRelationInfo includes an ID referring to "srs", the UE uses the same spatial domain transmit filter as the spatial domain transmit filter used to transmit the reference periodic SRS or the reference semi-persistent SRS to transmit the target SRS resource.

[0321] When the SRS is configured by a higher layer parameter [SRS-for-positioning] and the higher layer parameter spatialRelationInfo includes an ID referring to "DL-PRS-ResourceId", the UE transmits the target SRS resource using the same spatial domain transmit filter as that used to receive the reference DLPRS.

[0322] When the UE has an active semi-persistent SRS resource configuration and has not received a deactivation command, the semi-persistent SRS configuration is considered active in the active ULBWP, otherwise it is considered suspended.

[0323] When the UE is configured with one or more SRS resource configurations and the higher-layer parameter resourceType in SRS-Resource is set to "AP", the following operations are performed:

[0324] -UE receives SRS resource set configuration.

[0325] The UE receives commands based on DL DCI, group common DCI or UL DCI. The code point of DCI can trigger one or more SRS resource sets. For SRS in a resource set with usage set set to "codebook" or "antennaSwitching", the minimum time interval between the last symbol of the PDCCH that triggers AP SRS transmission and the first symbol of the SRS resource is N 2 Otherwise, the minimum time interval between the last symbol of the PDCCH that triggers the AP SRS transmission and the first symbol of the SRS resource is N 2 + 14. The minimum time interval in OFDM symbols is calculated based on the minimum subcarrier spacing between PDCCH and AP SRS.

[0326] When the UE receives DCI triggering AP SRS in time slot n, the UE transmits AP SRS in each of the triggered SRS resource sets in the time slot as defined in equation (2) below.

[0327]

[0328] In equation (2), k is configured by the higher layer parameter slotOffset for each triggered SRS resource set and is based on the subcarrier spacing of the triggered SRS transmission. SRS and μ PDCCH They are respectively the subcarrier spacing configuration of the triggered SRS and the PDCCH carrying the triggering command. and μ offsetRefers to the scheduling carrier and the scheduled carrier when performing carrier aggregation.

[0329] -When the UE is configured by a higher layer parameter spatialRelationInfo including an ID referring to "ssb-Index", the UE uses the same spatial domain transmit filter as the spatial domain transmit filter used to receive the reference SS / PBCH block to transmit the target SRS resource. When the UE is configured by a higher layer parameter spatialRelationInfo including an ID referring to "csi-RS-Index", the UE uses the same spatial domain transmit filter as the spatial domain transmit filter used to receive the reference periodic CSI-RS, the reference semi-persistent CSI-RS or the latest reference AP CSI-RS to transmit the target SRS resource. When the UE is configured by a higher layer parameter spatialRelationInfo including an ID referring to "srs", the UE uses the same spatial domain transmit filter as the spatial domain transmit filter used to transmit the reference periodic SRS, the reference semi-persistent SRS or the reference AP SRS to transmit the target SRS resource. When the SRS is configured by a higher layer parameter [SRS-for-positioning] and the higher layer parameter spatialRelationInfo includes an ID referring to "DL-PRS-ResourceId", the UE transmits the target SRS resource using the same spatial domain transmit filter as that used to receive the reference DL PRS.

[0330] When the UE receives the spatial relationship update command of the SRS resource and sends the HARQ-ACK information corresponding to the PDSCH carrying the update command in time slot n, the UE receives the spatial relationship update command of the SRS resource and sends the HARQ-ACK information corresponding to the PDSCH carrying the update command in time slot n. Starting from the first time slot thereafter, the corresponding actions and UE assumptions regarding updating the spatial relationship of the SRS resources are applied for SRS transmission. The update command includes the spatial relationship assumptions provided by a list of references to reference signal IDs, one for each element of the updated SRS resource set. Each ID in the list refers to: a reference SS / PBCH block, an NZP CSI-RS resource configured on the serving cell indicated by the Resource Serving Cell ID field in the update command (when there is the same serving cell as the SRS resource set), or an SRS resource configured on the serving cell and UL BWP indicated by the Resource Serving Cell ID field and Resource BWP ID field in the update command (when there is the same serving cell and the same BWP as the SRS resource set). When the UE is configured with the higher layer parameter usage set to "antennaSwitching" in the SRS-ResourceSet, the UE does not expect to be configured with different spatial relationships of SRS resources in the same SRS resource set.

[0331] The UE does not expect to be configured with different time domain behaviors for SRS resources in the same SRS resource set. The UE does not expect to be configured with different time domain behaviors between SRS resources and associated SRS resource sets. As shown in Table 15, the SRS request field in DCI formats 0_1, 1_1, and 0_2 indicates the triggered SRS resource set, while the SRS request field in DCI format 1_2 indicates the triggered SRS resource set.

[0332] When the higher layer parameter srs-TPC-PDCCH group for the UE is set to "typeB", the 2-bit SRS request field in DCI format 2_3 indicates the triggered SRS resource set. When the higher layer parameter srs-TPC-PDCCH-Group for the UE is set to "typeA", the 2-bit SRS request field in DCI format 2_3 indicates SRS transmission on a set of service cells configured by the higher layer. In more detail, the operation of triggering the SRS resource set using the SRS request field in Rel-15 / 16 will be described. When the UE receives DCI formats 0_1, 0_2, 1_1, 1_2 and 2_3 including the SRS request field from the BS, the UE determines whether the aperiodicSRS-ResourceTrigger or aperiodicSRS-ResourceTriggerList of the higher layer parameter SRS-resourceSet in which the time domain transmission is configured as "AP" is the same as or corresponds to the SRS request field in the DCI. The UE sends (multiple) SRS-ResourceSets including the same aperiodicSRS-ResourceTrigger or aperiodicSRS-ResourceTriggerList as the SRS request field. Depending on n in which the DCI is received and the slotOffset X configured in the higher layer parameter SRS-ResourceSet, the timing of sending the triggered AP SRS can be semi-statically determined as n+X.

[0333] Table 15

[0334]

[0335]

[0336]

[0337] For PUCCH and SRS scheduled on the same carrier, when semi-persistent SRS and periodic SRS are configured in the same symbol as PUCCH carrying only CSI reports, only L1 reference signal received power (RSRP) reports, or L1 signal to interference and noise ratio (SINR) reports, the UE does not send SRS. When semi-persistent SRS or periodic SRS is configured or AP SRS is triggered to be sent in the same symbol as PUCCH carrying HARQ confirmation, link recovery request and / or scheduling request (SR), the UE does not send SRS. When SRS is not sent due to overlap with PUCCH, only the (multiple) SRS symbols overlapping with PUCCH are discarded. When APSRS is triggered to be sent to overlap with PUCCH carrying only semi-persistent / periodic CSI reports, only semi-persistent / periodic L1-RSRP reports, or only L1-SINR reports in the same symbol, PUCCH is not sent.

[0338] In case of intra-band carrier aggregation or inter-band carrier aggregation band-band combination where simultaneous SRS and PUCCH / PUSCH transmission is not allowed, the UE does not expect to configure SRS from a carrier and PUSCH / UL DMRS / UL PT-RS / PUCCH formats from different carriers in the same symbol.

[0339] In case of intra-band carrier aggregation or inter-band carrier aggregation band-band combination where simultaneous SRS and PRACH transmission is not allowed, the UE does not simultaneously transmit SRS from a carrier and PRACH from a different carrier.

[0340] When an SRS resource with a higher layer parameter resourceType set to "AP" is triggered on (multiple) OFDM symbols for periodic / semi-persistent SRS transmission, the UE sends AP SRS resources, and (multiple) periodic / semi-persistent SRS symbols overlapping with (multiple) symbols are discarded, and (multiple) periodic / semi-persistent SRS symbols not overlapping with (multiple) symbols are sent. When an SRS resource with a higher layer parameter resourceType set to "semi-persistent" is triggered on OFDM symbols for periodic SRS transmission, the UE sends semi-persistent SRS resources, and (multiple) periodic SRS symbols overlapping with (multiple) symbols are discarded, and (multiple) periodic SRS symbols not overlapping with (multiple) symbols are sent.

[0341] When the UE is configured by higher layer parameters with usage in the SRS-ResourceSet set to "antennaSwitching" and a guard period of Y symbols is configured, the UE uses the same priority rules as defined above during the guard period as if SRS was configured.

[0342] When the higher layer parameter spatialRelationInfo is activated or updated for semi-persistent or AP SRS resources by MAC CE for the set of CC / BWPs indicated by the higher layer parameter [applicableCellList], the higher layer parameter spatialRelationInfo is applied to (multiple) semi-persistent or AP SRS resources with the same SRS resource ID for all BWPs in the indicated CC.

[0343] When the higher layer parameter enableDefaultBeamPlForSRS is set to "enabled", the higher layer parameter spatialRelationInfo of the SRS resources (except the SRS resources whose usage in the higher layer parameter SRS-ResourceSet is set to "beamManagement", or the SRS resources whose usage in the higher layer parameter SRS-ResourceSet is set to "nonCodebook" and configured as associatedCSI-RS) is not configured in FR2, and the UE is not configured with the higher layer parameter pathlossReferenceRS, the UE sends the target SRS resources as follows.

[0344] - The UE transmits the target SRS resources using the same spatial domain transmit filter as used for receiving the CORESET with the lowest controlResourceSetID in the activated DL BWP in the CC.

[0345] - When the UE does not have any CORESET configured in a CC, the UE transmits the target SRS resources using the same spatial domain transmit filters as used to receive the activated TCI state with the lowest ID of the PDSCH in the activated DL BWP applicable to the CC.

[0346] Figure 6a A MAC CE configuration for activation / deactivation of SP SRS according to an embodiment is shown.

[0347] refer to Figure 6a , the network can activate and deactivate the configured SP SRS resource set of the serving cell by sending the SP SRS activation / deactivation MAC CE. The configured SP SRS resource set is initially deactivated at configuration and after handover.

[0348] The SP SRS activation / deactivation MAC CE may be identified by a MAC subheader with LCID as described in Table 16.

[0349] Table 16

[0350] index LCID value … … 48 SP ZP CSI-RS resource set activation / deactivation 49 PUCCH spatial relationship activation / deactivation 50 SP SRS activation / deactivation 51 SP CSI reporting activation / deactivation on PUCCH 52 UE-specific PDCCH TCI status indication … …

[0351] index LCID value … … 42 AP SRS spatial relationship indication … … 48 SP ZP CSI-RS resource set activation / deactivation 49 PUCCH spatial relationship activation / deactivation 50 SP SRS activation / deactivation 51 SP CSI reporting activation / deactivation on PUCCH 52 UE-specific PDCCH TCI status indication … …

[0352] The SP SRS activation / deactivation MAC CE includes the following fields and can be Figure 6a As shown:

[0353] -A / D 6a-00: This field indicates whether the SP SRS resource set is activated or deactivated. To indicate activation, this field is set to 1, otherwise, it indicates deactivation.

[0354] - Cell ID of SRS resource set 6a-05: This field indicates the identity of the serving cell and includes the activated / deactivated SP SRS resource set. When the C field 6a-15 is set to 0, this field indicates the cell ID of the serving cell and includes the activated / deactivated SP SRS resource set. i The ID of the serving cell for all resources indicated by the field. The length of this field is 5 bits.

[0355] - BWP ID of SRS resource set 6a-10: This field indicates the UL BWP of the codepoint with the DCI bandwidth part indicator field and includes the activated / deactivated SP SRS resource set. When the C field 6a-15 is set to 0, this field indicates the UL BWP of the codepoint with the DCI bandwidth part indicator field and includes the activated / deactivated SP SRS resource set. i The BWP ID of all resources indicated by the field. The length of this field is 2 bits.

[0356] -C 6a-15: This field indicates whether the octet including the Resource Serving Cell ID field and the Resource BWP ID field exists. When this field is set to 1, it indicates that the octet including the Resource Serving Cell ID field and the Resource BWP ID field exists, otherwise, it indicates that the octet does not exist.

[0357] -SUL 6a-20: This field indicates whether the MAC CE applies to a normal UL (NUL) carrier configuration or a SUL carrier configuration. When this field is set to 1, it indicates that the MAC CE is applied to the SUL carrier configuration, and when this field is set to 0, it indicates that the MAC CE is applied to the NUL carrier configuration.

[0358] - SP SRS Resource Set ID 6a-25: This field indicates the activated or deactivated SP SRS resource set ID identified by SRS-ResourceSetId. The length of this field is 4 bits.

[0359] -Fi 6a-30: This field indicates the type of resource used as the spatial relationship of the SRS resource in the SP SRS resource set indicated by the SP SRS resource set ID field. 0 Refers to the first SRS resource in the resource set, F 1 Refers to the second SRS resource, and so on. i Can be mapped to an SRS resource in an SP SRS resource set. This field is set to 1 to indicate that an NZP CSI-RS resource index is used, and this field is set to 0 to indicate that an SSB index or an SRS resource index is used. The length of this field is 1 bit. This field only appears when the MAC CE is used for activation, that is, the A / D field is set to 1.

[0360] - Resource ID i 6a-35: This field contains the resource ID used for spatial relationship derivation of SRS resource i. Resource ID 0 Refers to the first SRS resource in the resource set, resource ID 1 Refers to the second SRS resource, and so on. Resource ID i Can be mapped to the SRS resources in the SP SRS resource set. i When F is set to 0 and the first bit of this field is set to 1, the remainder of this field contains the SSB-Index. i When set to 0 and the first bit of this field is set to 0, the remainder of this field contains SRS-ResourceId. The length of this field is 7 bits. This field only appears when the MAC CE is used for activation, that is, the A / D field is set to 1.

[0361] - Resource service cell ID i 6a-40: This field indicates the identifier of the serving cell where the resource used for spatial relationship derivation of SRS resource i is located. The length of this field is 5 bits.

[0362] - Resource BWP ID i 6a-45: This field indicates the UL BWP with the codepoint of the DCI bandwidth part indicator field, on which the resource for spatial relation derivation of SRS resource i is located. The length of this field is 2 bits.

[0363] -R: Reserve bit, set to 0.

[0364] Figure 6b A MAC CE configuration for spatial relationship indication of AP SRS according to an embodiment is shown.

[0365] refer to Figure 6bIn order to indicate the spatial relationship of AP SRS, an AP SRS spatial relationship indication MAC CE may be configured (according to the example of Release 16). The AP SRS spatial relationship indication MAC CE may be identified by a MAC subheader, where the LCID value is set to 42. The AP SRS spatial relationship indication MAC CE includes the following fields and may be as follows: Figure 6b As shown:

[0366] - Cell ID of SRS resource set 6b-05: This field indicates the identity of the serving cell that includes the indicated AP SRS resource set. When the C field is set to 0, this field indicates the identity of the serving cell that includes the resource ID i The identifier of the serving cell for all resources indicated. The length of this field is 5 bits.

[0367] - BWP ID of SRS resource set 6b-10: This field indicates the UL BWP of the codepoint with the DCI bandwidth part indicator field and includes the activated SRS resource set. When the C field is set to 0, this field indicates the UL BWP of the codepoint with the DCI bandwidth part indicator field and includes the activated SRS resource set. i The identifier of the BWP for all resources indicated.

[0368] -C 6b-15: This field indicates whether the octet including the Resource Serving Cell ID field and the Resource BWP ID field exists. When this field is set to 1, the octet including the Resource Serving Cell ID field and the Resource BWP ID field exists, otherwise, the octet does not exist.

[0369] -SUL 6b-20: This field indicates whether the MAC CE applies to NUL carrier configuration or SUL carrier configuration. When the MAC CE is applied to SUL carrier configuration, this field is set to 1, and when the MAC CE is applied to NUL carrier configuration, this field is set to 0.

[0370] -AP SRS Resource Set ID 6b-25: This field indicates the AP SRS resource set ID identified by SRS-ResourceSetID. The length of this field is 4 bits.

[0371] -F i 6b-30: This field indicates the type of resource used as the spatial relationship of the SRS resource in the AP SRS resource set indicated by the AP SRS resource set ID field. 0 Refers to the first SRS resource in the resource set, F 1 refers to the second SRS resource, and so on. In this way, another F iThe relationship between the A / D field and the SRS resource. This field is set to 1 to indicate that the NZP CSI-RS resource index is used, and this field is set to 0 to indicate the SSB index or SRS resource index. The length of this field is 1 bit. This field only exists when the MAC CE is used for activation, that is, the A / D field is set to 1.

[0372] - Resource ID1 6b-35: This field contains the ID of the resource used for spatial relationship derivation of SRS resource i. Resource ID 0 Refers to the first SRS resource in the resource set, resource ID 1 refers to the second SRS resource, and so on. In this way, the relationship between another resource ID1 and the SRS resource can be defined. i When set to 0 and the first bit of this field is set to 1, the remainder of this field includes SRS-ResourceId. The length of this field is 7 bits.

[0373] - Resource service cell ID i 6b-40: This field indicates the ID of the serving cell where the resource used for spatial relationship derivation of SRS resource i is located. The length of this field is 5 bits.

[0374] - Resource BWP ID i 6b-45: This field indicates the UL BWP of the codepoint with the DCI bandwidth part indicator field, on which the resource for spatial relation derivation of SRS resource i is located. The length of this field is 2 bits.

[0375] The AP SRS is triggered according to the code point indicated by the SRS resource set configured in the higher layer and the field in the DCI for triggering the SRS. Although the operation for triggering the AP SRS is described for ease of description, the AP SRS is merely an example of a UL reference signal, and the same description may apply to the operation for triggering another type of UL reference signal. In addition to supporting the 5G wireless communication system by using frequency range 1 (FR1), technical development for supporting the 5G wireless communication system by using frequency range 2 (FR2) is actively underway. FR2 is located in a higher frequency band than FR1, so an increased number of AP SRSs can be triggered to support UL with an extended frequency bandwidth. As more and more AP SRSs are triggered, the DCI overhead required to trigger the AP SRS may increase significantly at a certain point in time. Due to the significantly increased AP SRS triggering overhead, the restricted resources for PDCCH transmission may be insufficient, so the AP SRS may not be triggered in the desired time domain, and the DCI for other operations to be sent through the same PDCCH may not be sent.

[0376] In the existing environment of statically triggered AP SRS, when AP SRS is triggered and then the BWP in which the UE operates changes, the BWP change configuration may not be dynamically performed for the triggered AP SRS. Considering the changed BWP, the SRS resources for the changed BWP should be selected from the SRS resource set in the SRS-config configured in the higher layer and triggered again, and the SRS transmission of the SRS resources previously triggered before the BWP change should not be performed. When this operation is supported by the existing AP SRS triggering method, the triggering is performed according to the operation based on the higher layer, and the change situation such as the BWP change may not be quickly reflected and supported.

[0377] When triggering AP SRS in the existing method, a value identical to a value in aperiodicSRS-ResourceTrigger or aperiodicSRS-ResourceTriggerList in a higher layer parameter SRS-ResourceSet may be configured and indicated through the SRS request field in DCI. When using this method, a value configured in AperiodicsRS-ResourceTrigger or AperiodicsRS-ResourceTriggerList may be indicated through DCI, and SRS may be sent only according to the SRS-Resource configured in the higher layer as described above. In Rel-15 / 16, by considering the time slot n in which the PDCCH including the SRS request field is received and the slotOffset X configured in the higher layer parameter SRS-ResourceSet, the timing of sending the SRS resource set indicated by the SRS request field is determined to be n+X

[0378] When supporting a UE in a time division duplex (TDD) manner, in order for the BS to transmit an AP SRS in a desired time slot, a triggering DCI should be transmitted in a specific time slot according to the TDD time slot configuration and the slotOffset value of the SRS resource set to be transmitted. For example, when the BS is able to transmit DCI in the first time slot, the second time slot, the third time slot, and the fourth time slot, and a trigger is performed to transmit SRS resource set 1 with slotOffset set to 2 in the fifth time slot, the base station should transmit a DCI for triggering SRS resource set 1 in the third time slot. In the same case, when a trigger is performed to transmit SRS resource set 2 with slotOffset set to 3 in the sixth time slot, the base station should transmit a DCI for triggering SRS resource set 2 in the third time slot. In this way, when multiple AP SRS triggering is required, the DCI overhead may increase at a specific time point. When SRS is triggered and the UL resources to be transmitted are occupied due to another operation such as PUCCH transmission with a higher priority, and therefore SRS cannot be transmitted according to the preset SRS resource configuration, additional SRS triggering may be required. When the SRS that cannot be transmitted is triggered again, the DCI overhead may be additionally increased.

[0379] Therefore, the AP SRS triggering method should be supplemented according to the increased AP SRS usage. The following methods can be considered to supplement the AP SRS triggering method.

[0380] As a first method, in order to support UL of extended frequency without increasing DCI overhead, the BS can increase the number of SRS-ResourceSets included in the list in the higher layer parameter SRS-Config and the number of SRS-Resources included in the SRS-ResourceSet, and can make the UE share the information so that the number of SRS resource sets and SRS resources configured simultaneously by aperiodicSRS-ResourceTrigger or aperiodicSRS-ResourceTriggerList indicating the SRS trigger state increases. However, this method may have disadvantages because the AP SRS is triggered with a fixed number of SRS resource sets and resources configured in a higher layer, so the SRS resources may not be dynamically managed.

[0381] As a second method, the BS can support the UE by distributing DCI overhead, which may increase significantly at a specific time point due to AP SRS triggering. The DCI overhead that increases significantly due to the increase in the number of AP SRS triggering can be distributed by distributing the existing AP SRS triggering. When the AP SRS trigger is distributed, it indicates that the DCI sent in a specific time slot as in the example above is distributed and sent in the time domain. In order to distribute and send the DCI for triggering AP SRS along the time axis, a method of dynamically determining the transmission timing by using an additional offset indicated by the DCI can be used, instead of semi-statically determining the transmission timing using a slotOffset fixed in a higher layer.

[0382] When distributed AP SRS triggering is performed for each group of a group consisting of multiple UEs, the DCI overhead required to trigger the AP SRS of each UE can be reduced. When the triggered AP SRS transmission and another physical channel signal transmission such as PUCCH transmission for HARQ-ACK overlap each other or perform BWP changes, the AP SRS cannot be sent on the corresponding UL resource. In order to solve this problem, a method for dynamically triggering AP SRS is needed. The dynamic AP triggering in the embodiment of the present disclosure refers to an operation including triggering AP SRS and an operation of dynamically determining the transmission timing of AP SRS. As a method for reducing the DCI overhead caused by AP SRS triggering and a method for dynamically performing AP SRS triggering, the present disclosure provides DCI overhead management for increased AP SRS triggering, flexible offset control based on DCI, automatic delay and group common DCI control. For flexible offset control based on DCI, the AP SRS triggering offset can be sent in the DCI, and it can be indicated to perform one or more operations of "reservation", "adjustment", "reordering" and "cancellation". The AP SRS triggering offset transmitted in the DCI refers to an offset for dynamically determining the transmission timing of the triggered AP SRS (eg, a time slot offset or an SRS resource set ID pair for AP SRS transmission reordering).

[0383] In addition to DCI-based flexible offset control, a method of automatically delaying the triggered AP SRS in sequence until the AP SRS is sent on the available UL resources and continuously automatically delaying until the offset of sending the SRS can be used. A group-common DCI control method can jointly send a group-based dynamic offset or a group-based cancellation indication to all UEs belonging to a group. In order to perform dynamic AP SRS triggering, a MAC CE for AP SRS triggering can be used. Activation information about the AP SRS resource set configured in a higher layer can be indicated by a MAC CE, and the code point included in the DCI can be referenced so that the AP SRS can be triggered, or a code point for a dynamic AP SRS triggering offset can be defined by a MAC CE, which can be indicated by the DCI, so that the AP SRS triggering offset can be determined. The BS can send a MAC CE including a new slotOffset to the UE in order to change the slotOffset configured in the higher layer parameter SRS-ResourceSet.

[0384] The UL signal considered in the present disclosure includes SRS, and the signaling for UL signal transmission of the BS includes some or all of higher layer signaling including RRC or MAC CE or L1 signaling including DCI. The dynamic triggering method of AP SRS signal transmission of the UE in various situations will be described in detail in the following embodiments of the present disclosure.

[0385] The present disclosure provides a DCI overhead management method for AP SRS triggering through the following embodiments. The present disclosure provides a method by which a BS performs dynamic AP SRS triggering using a flexible offset based on DCI. The present disclosure provides a method by which, when a BS triggers AP SRS to a UE, the operation of the UE is determined by automatic delay according to available UL transmission resources. The present disclosure provides a method by which a BS performs APSRS triggering or trigger cancellation on one or more UEs through a group common DCI.

[0386] Although Embodiments 1 to 3 are described here, the embodiments of the present disclosure may be combined and implemented. That is, for the convenience of description, the number of embodiments of the present disclosure is provided, and the present disclosure is not limited thereto, and different embodiments of the present disclosure may be combined.

[0387] Example 1 : DCI Overhead Management Method for Increased AP SRS Triggering

[0388] In order for the BS to support UL in the extended bandwidth, as described above, the number of required AP SRSs is increased according to the purpose of the SRS, and the DCI overhead increased for triggering the AP SRS should be resolved. As a method of resolving the DCI overhead, there are i) a method of increasing the number of SRS-ResourceSets whose time domain behavior is AP in the SRS resource set list of the higher layer parameter SRS-config and increasing the number of SRS resource sets and resources triggered at the same time, and ii) a method of distributing the DCI overhead increased at a specific time by distributing the AP SRS trigger.

[0389] In order to increase the resource sets and resources of AP SRS triggered based on higher layer parameters, the BS can support the UE by updating the higher layer parameters. The BS can trigger AP SRS with the SRS resource sets and SRS resources configured in the SRS resource set list SRS-ResourceSetToAddModlist and the SRS resource list srs-ResourceToAddModList in the higher layer parameter SRS-Config. In the NR system, the maximum configurable number of SRS resource sets (maxNrofSRS-ResourceSets) in the list srs-ResourceSetToAddModList is 16, and the maximum configurable number of SRS resources (maxNrofSRS-Resources) in the list srs-ResourceToAddModList is 64 (according to the example of Release 15).

[0390] As described above, a UE receiving DCI format 0_1, 1_1, or 2_3 sent by a BS can trigger an SRS resource set and resource in which the resource type (resourceType) is set to AP by referring to a value in aperiodicSRS-ResourceTrigger or aperiodicSRS-ResourceTriggerList indicated by the SRS request field. In this case, the UE can trigger (multiple) SRS resource sets, in which the aperiodicSRS-ResourceTrigger value in the AP SRS resource set is the same as the value indicated by the SRS request in the DCI, and can only trigger the SRS resource sets present in the configuration list. Therefore, when the SRS resource sets and SRS resources used for AP SRS increase, the number of APSRS resource sets and resources triggered simultaneously by the DCI can increase. At this time, the BS can configure the parameter slotOffset configured for each SRS-ResourceSet to be from 1 to 32, or when a larger range of slot offsets is required, by configuring the parameter slotOffset to be from 1 to greater than 32.slotoffset , to trigger the UE's AP SRS.

[0391] The BS can support the UE by increasing the maximum configurable value maxNrofSRS-TriggerStates-1 of aperiodicSRS-ResourceTrigger to trigger AP SRS for the increased SRS resource set or resource. In the existing NR system, the BS can support the UE by setting aperiodicSRS-ResourceTrigger to maxNrofSRS-TriggerStates-1=3 (according to the example of Release 15). When the BS increases the maximum configurable value maxNrofSRS-TriggerStates-1 as the AP SRS resource set increases, AP SRS can be triggered by using various combinations of SRS resource sets.

[0392] The BS can distribute and trigger the AP SRS to be sent by the UE. Although the BS distributes and sends the trigger DCI for each AP SRS resource set, the BS can configure the UE to send the AP SRS resource at the same transmission timing by considering the time point of triggering the higher layer parameter slotOffset and the transmission timing of the AP SRS. For example, an SRS resource set triggered in time slot n and in which the slotOffset in the higher layer parameter SRS-ResourceSet is set to L and an SRS resource set triggered in time slot n-1 and in which the slotOffset in the higher layer parameter SRS-ResourceSet is set to L+1 can be sent at the same timing. In this way, because the DCI for triggering each SRS resource set is not sent to the UE at the same time, but is distributed and sent to the UE, a significant increase in DCI overhead due to DCI used for AP SRS triggering during a specific duration can be prevented.

[0393] Example 2 :DCI-based flexible offset control method for AP SRS transmission of UE

[0394] Embodiment 2 provides a method for performing dynamic APSRS triggering by adding or replacing a DCI-based flexible offset control method for AP SRS triggering performed based on higher layer parameters. That is, in Embodiment 2, a method for dynamically determining AP SRS transmission timing will be described. In Rel-15 / 16, AP SRS triggering is dynamically performed through DCI, and AP SRS transmission timing is semi-statically configured using SlotOffset in a higher layer parameter SRS-ResourceSet. The detailed embodiments of the present disclosure provide various methods for dynamically indicating AP SRS transmission timing based on DCI. As described above, the DCI-based flexible offset control method may include four independent operations, such as "reservation", "adjustment", "reordering" and "cancellation" or a combination thereof. The BS may send a DCI for flexible offset control to the UE based on the transmittable UL resources and the triggered AP SRS. The term "flexible offset control" refers to dynamically determining the transmission timing of the AP SRS by using an offset additionally indicated by the DCI, as described above, the transmission timing of the AP SRS configured semi-statically in Rel-15 / 16. The additional offset may be indicated by an additional field in a DCI that includes an SRS request field for triggering an AP SRS, or may be indicated by another DCI. Each flexible offset control method will be described in detail in Embodiment 2-1, Embodiment 2-2, Embodiment 2-3, and Embodiment 2-4. Embodiment 2-5 provides a method for managing an AP SRS triggered according to the capabilities of a UE. Each embodiment of the present disclosure may operate independently of other embodiments, or may operate in combination with consideration thereof.

[0395] Example 2-1 : AP SRS retention method using flexible trigger offset

[0396] In Embodiment 2-1, an operation of adjusting the transmission timing of the AP SRS by dynamically changing the transmission timing of the AP SRS by using a field additionally indicated in the DCI will be described.

[0397] As one of the methods for dynamically triggering AP SRS, the BS may send a new offset for triggering AP SRS to the UE via DCI. In this case, the slot offset may be considered as an example of a new offset. When the new offset includes slot offset information for SRS transmission, the UE may determine the AP SRS transmission timing by referring to the slot offset information. That is, the BS may indicate to the UE via DCI a new offset (slotOffset) for dynamically determining the transmission timing of AP SRS. The new offset may be indicated by a new field in the DCI. The new field for indicating the new offset may be configured as in Embodiment 4 described below. The new field for indicating the new offset may exist in the DCI including the SRS request field, or may exist in a DCI independent of the DCI including the SRS request field. The new offset sent via DCI may trigger AP SRS together with the offset configured by a higher layer parameter, or may trigger AP SRS alone. Regarding the method of triggering AP SRS, AP SRS can be triggered in the same manner as in Rel-15 / 16 through the SRS request field, and in this case, the transmission timing of APSRS can be determined by referring to both the added new offset field and the Rel-15 / 16 higher layer parameter slotOffset or by referring to only the new offset field. Figure 7 and Fig. 9 Describe the method of dynamically triggering AP SRS.

[0398] The following parameters may be defined so that the final transmission timing of the AP SRS is determined by considering the time slot offset configured in the higher layer and the new field in the DCI that dynamically indicates the transmission timing of the AP SRS. The offset configured in the higher layer is defined as X, and the new offset sent through the DCI is defined as Y. The offset X configured in the higher layer refers to the slotOffset configured in the higher layer parameter SRS-ResourceSet. When the UE receives a PDCCH including a DCI for triggering the AP SRS based on a higher layer parameter (e.g., RRC configuration) in time slot n and receives a PDCCH including a DCI for dynamically triggering the AP SRS in time slot n', the timing for sending the corresponding SRS may be defined as follows according to the dynamic AP SRS triggering method using the new offset. In this case, the SRS request field for triggering the AP SRS and the field for the new offset may be included in one DCI, or may be indicated by separate DCIs respectively. Although for the sake of convenience of description, in Figures 7 to 9 Each field in is indicated by a separate DCI, but the present disclosure is not limited thereto, and the SRS request field and the field for the new offset may be indicated by the same DCI.

[0399] Figure 7A method according to an embodiment is shown, by which the UE determines the AP SRS transmission timing by using an offset received based on higher layer configuration information and a new offset for dynamically triggering the AP SRS.

[0400] refer to Figure 7 , an operation of determining the AP SRS transmission timing by using the time slot offset X configured in a higher layer and the time slot offset Y configured by DCI for dynamically triggering the AP SRS will be described. Specifically, the UE can determine the AP SRS transmission timing by associating the offset Y configured by the DCI with the offset X. By considering two time slots and time slot n, the UE can define the AP SRS transmission timing as n+X+Y, where the PDCCH including the DCI indicating the AP SRS triggering based on the higher layer parameters is received in time slot n.

[0401] exist Figure 7 , as an example of the operation, the UE updates the transmission timing (7-15) of the AP SRS resource set 7-05 triggered by the higher layer by considering the offset X for triggering the AP SRS based on the higher layer and the offset Y for dynamically triggering the AP SRS. That is, the UE may receive the DCI 7-00 including the SRS request field in time slot n, which is required to determine the offset X (e.g., X=3) for triggering the AP SRS based on the higher layer parameters (e.g., RRC configuration). The UE may receive the DCI including the new offset Y (e.g., Y=3) for dynamically triggering the AP SRS in time slot n+1. In this case, the UE may determine the AP SRS transmission timing as n+X+Y (=n+6), and may send the AP SRS in time slot n+6.

[0402] The offset Y may include an offset Y candidate value configured by higher layer signaling and indirectly indicated by the DCI or a value directly indicated by the DCI. When the higher layer parameter slotOffset is not configured (the slotOffset field does not exist), the configuration of the new offset Y is indicated by higher layer signaling, and an indicator for indicating the offset Y is transmitted by the DCI, the UE may recognize that X is 0, and may determine that the AP SRS transmission timing is n+Y based on the time slot n for receiving the DCI including the new offset Y and the SRS request field.

[0403] Figure 8 A method according to one embodiment is shown by which the UE determines the AP SRS transmission timing by using a new slot offset for dynamically triggering the AP SRS.

[0404] Reference Figure 8, an operation of determining the AP SRS transmission timing by using only the new slot offset Y configured by DCI and ignoring the slot offset X configured in a higher layer will be described. Specifically, when the UE receives a DCI for dynamically triggering the AP SRS, the UE may ignore the slot offset X. The DCI for dynamically triggering the AP SRS may include the slot offset Y. By considering the slot offset Y and the slot n, the UE may define the AP SRS transmission timing as n+Y, in which the PDCCH including the DCI indicating the triggering based on the higher layer parameters is received. That is, referring to Figure 8 , the UE can determine the APSRS transmission timing by using only the time slot offset Y. When the UE receives the offset Y for dynamically triggering the AP SRS, the UE can ignore the offset X based on the higher layer parameters previously received, and can determine the transmission timing of the AP SRS resource set (8-15). That is, the UE can receive the DCI 8-00 including the SRS request field in time slot n, which is required to determine the offset X (e.g., X=3) for triggering the AP SRS based on the higher layer parameters (e.g., RRC configuration). The UE can receive the DCI including the new offset Y (e.g., Y=6) for dynamically triggering the AP SRS in time slot n+1. In this case, when the UE receives the DCI 8-10 for the offset Y, the UE can ignore the offset X, can determine that the AP SRS transmission timing is n+Y (=n+6), and can send the AP SRS in time slot n+6.

[0405] Fig. 9 A method according to one embodiment is shown, by which the UE determines the AP SRS transmission timing by dynamically triggering the AP SRS using a slot index in a frame.

[0406] refer to Fig. 9 , an operation will be described in which the UE ignores the slot offset X configured in a higher layer, uses only the new offset Z configured through the DCI, and determines the AP SRS transmission timing when the offset Z indicates a specific slot index in the frame. When the UE receives the DCI for dynamically triggering the AP SRS, the UE may ignore the slot offset X. The offset Z may indicate the index of the slot in which the AP SRS is transmitted in the current transmission frame, such as Fig. 9 As shown. According to μ indicating the subcarrier spacing, the new offset Z can be set to a value of 0 to 10·2 μ-1 In detail, the offset Z may be used to indicate the timing of transmitting the AP SRS in each frame.

[0407] exist Fig. 9In , μ indicates that the subcarrier spacing is set to 0, and the number of time slots included in one frame is 10. For example, when the offset Z is 6, the UE may send the AP SRS in time slot n+6, time slot n+16, time slot n+26, ..., applying the offset 6 thereto every frame. It is assumed that time slot n is the 0th time slot of the frame. Specifically, when the AP SRS can be transmitted in a time slot whose time slot index is 6 within a frame including a time slot in which the offset Z is received, the AP SRS is transmitted in time slot n+6. When the AP SRS cannot be transmitted in time slot n+6, the APSRS may be transmitted in a time slot whose time slot index is 6 within the next frame including a time slot in which the offset Z is received. When time slot n is the kth time slot, instead of the 0th time slot in the frame, the AP SRS transmission timing considering the new offset Z (e.g., Z=6) may be determined as the sixth time slot in the frame, such as time slot n-k+6, time slot n-k+16, time slot n-k+26, ...

[0408] The UE may receive a DCI 9-00 including an SRS request field in slot n, which is required to determine an offset X (e.g., X=3) for triggering AP SRS based on a higher layer parameter (e.g., RRC configuration). The UE may receive a DCI including a new offset Z (e.g., Z=6) for dynamically triggering AP SRS in slot n+1. When the UE receives the DCI 9-10 for offset Z, the UE may ignore the offset X, may determine that the AP SRS transmission timing is the sixth slot of each frame, and may transmit the AP SRS in slot n+6, slot n+16, slot n+26, and the like. In this case, it is assumed that slot n is the 0th slot in the frame. When slot n is the kth slot instead of the 0th slot in the frame, the UE may transmit the AP SRS in slot -k+6, slot n-k+16, slot n-k+26, and the like, as shown in the above example.

[0409] Although for the convenience of description, Figures 7 to 9 In the embodiment of the present invention, a DCI including an SRS request field is received in time slot n, and a DCI including a new time slot offset is received in time slot n'=n+1, but n and n' may be set to the same value, and in this case, the SRS request field and the field for the new offset may be indicated by one DCI, or may be indicated by separate DCIs. When n'≠n, the SRS request field and the field for the new offset are indicated by different DCIs.

[0410] By considering the minimum time interval K according to usage (K=N when the usage of AP SRS is set to "codebook" or "antennaSwitching") 2 symbols (PUSCH preparation time), and K = N in other cases2 +14 symbols), the AP SRS transmission timing indicated in the method of Embodiment 2-1 should be greater than n'+K. When the configured AP SRS transmission timing is not greater than n'+K, the AP SRS can be transmitted by applying the automatic delay method or the offset control method described below, or the corresponding indication can be ignored.

[0411] Example 2-2 : Adjustment method for changing the triggered AP SRS transmission timing

[0412] As in Embodiment 2-1, the UE can determine the AP SRS transmission timing by using only the offset configured in the higher layer or by using the new offset indicated by the DCI. However, when a resource with a higher priority is transmitted at the pre-configured SRS transmission timing and thus the AP SRS cannot be transmitted, it may be necessary to change the configuration to delay the configured transmission timing and transmit the SRS at the delayed transmission timing. Conversely, the configuration may be changed to transmit the AP SRS at a timing earlier than the configured SRS transmission timing.

[0413] In order to dynamically change the AP SRS transmission timing by considering the changed UL transmission resource, an adjustment for changing the AP SRS offset based on the DCI may be performed. The adjustment for changing the AP SRS transmission timing may be performed by the preconfigured transmission timing T old and the time slot offset m used for adjustment, as shown below.

[0414] Fig.10 It is shown that the UE according to one embodiment changes the AP SRS transmission timing by using an offset for dynamically changing the AP SRS transmission timing and the pre-configured AP SRS transmission timing.

[0415] It can be assumed that the preconfigured AP SRS transmission timing is semi-statically determined using the slotOffset in the higher layer parameter SRS-ResourceSet, as in Rel-15 / 16 operation. Alternatively, it can be assumed that the preconfigured AP SRS transmission timing is determined by considering a new offset for dynamically determining the transmission timing as in Example 2-1. The slot offset for adjusting the preconfigured AP SRS transmission timing can be indicated by a DCI independent of the DCI including the SRS request field for triggering the AP SRS, and the independent DCI can be sent at a later time than the DCI including the SRS request field.

[0416] Reference Fig.10 , will describe the use of a pre-configured timing T oldThe UE can determine the transmission timing by comparing the timing adjustment offset m configured by the DCI with the pre-configured timing T old The AP SRS transmission timing is determined by association, and Fig.10 As shown, by receiving the offset m indicated by the DCI 10-10 for adjustment, the adjusted AP SRS transmission timing can be defined as the AP SRS transmission timing T new (=T old +m). In this case, T old It can be the AP SRS transmission timing determined by the above method. That is, T old It can be the transmission timing determined based on the offset Y or Z. old The AP SRS transmission timing may be triggered by the SRS request field based on the RRC configuration. The AP SRS transmission timing triggered by the SRS request field based on the RRC configuration refers to the timing determined for the triggered AP SRS according to the slotOffset in the higher layer parameter SRS-ResourceSet. The UE may apply an offset m (e.g., m=2) to the AP SRS in time slot n+1 (T old ) triggers the AP SRS10-05. Therefore, the UE can set the AP SRS transmission timing T new Change from time slot n+1 to n+3 (T old +2).

[0417] Fig.11 It is shown that the UE according to the embodiment changes the AP SRS transmission timing by using only the offset for dynamically changing the AP SRS transmission timing.

[0418] Reference Fig.11 , an operation of determining the transmission timing by using only the offset m configured by the last transmitted DCI including the timing adjustment information in addition to the pre-configured offset Y will be described. When the UE receives the DCI for adjusting the AP SRS transmission timing, the UE may cancel the DCI for determining the pre-configured timing T old The AP SRS transmission timing can be determined by using the offset m indicated by the last transmitted DCI. In this case, the adjusted AP SRS transmission timing can be defined as T new =T old -Y+m, such as Fig.11 shown.

[0419] The UE may apply an offset m (eg, m=2) to the time slot n+1 (T old). In this case, the offset Y (eg, Y=1) received earlier than the DCI 11-10 used for adjustment may be canceled. That is, the UE may set the transmission timing T of the AP SRS to new Change from time slot n+1 to n+2 (T old -1+2).

[0420] Fig.12 It is shown that the UE according to the embodiment changes the AP SRS transmission timing by using only the slot index in the frame for dynamically changing the AP SRS transmission timing.

[0421] Reference Fig.12 , a method will be described in which a UE determines the AP SRS transmission timing by using only the offset m configured by the DCI including the timing adjustment information regardless of the pre-configured timing T old How to operate. In detail, the UE may receive DCI 12-10 including the transmission timing adjustment information. The UE may configure an offset m based on the DCI 12-10, and the offset m may indicate a time slot for transmitting the AP SRS in each frame. In detail, the UE may ignore the pre-configured timing T based on the offset m. old .like Fig.12 As shown, after the UE receives the DCI 12-10 including the offset for adjustment, the UE may define the time slot m of each frame as the AP SRS transmission timing.

[0422] When the offset m included in the DCI 12-10 is 1, the UE may not transmit the AP SRS while receiving the DCI 12-10 in the time slot n+1 in which the DCI 12-10 is received. Therefore, the UE may transmit the APSRS 12-15 in the time slot n+11 which is the first time slot of the next frame. In addition, the UE may ignore the time slot n+2 which is the preconfigured timing T based on the DCI 12-10. old .

[0423] By considering the minimum time interval K according to the usage and the time slot n' in which the PDCCH including the DCI indicating the timing adjustment is received (K=N when the usage of AP SRS is set to "codebook" or "antennaSwitching") 2 symbols (PUSCH preparation time), and K = N in other cases 2 +14 symbol), the AP SRS transmission timing indicated in the above method should be greater than n'+K. When the configured AP SRS transmission timing is not greater than n'+K, the AP SRS can be transmitted by applying the automatic delay method or offset control method described below, or the corresponding indication can be ignored.

[0424] Example 2-3 : Reordering method for changing the order of triggered AP SRS

[0425] Embodiment 2-3 provides a method of changing the transmission order of triggered AP SRS by using additional DCI.

[0426] The BS can change the order of triggered AP SRS according to usage priority changes, available physical resource status, etc. For example, when an AP SRS resource set whose usage is set to "codebook" is triggered at an earlier timing than an AP SRS resource set whose usage is set to "beamManagement", and the BS determines that the AP SRS transmission set to "beamManagement" is prioritized, the BS can reorder the order of the corresponding AP SRS resource sets. Although the operation can be performed by adjusting the change offset provided by Example 2-2, when the operation is performed through the DCI for reordering, the AP SRS transmission timing can be exchanged by indicating only the index of the SRS whose order is to be changed. The operation according to the method of changing the order of triggered AP SRS can be defined as follows. Reference will be made to Figures 13 to 15 Operations according to the method of changing the order of triggered AP SRS are described.

[0427] The AP SRS before the sequence change can be dynamically triggered by the SRS request field included in the DCI, and the transmission timing can be semi-statically determined according to the slotOffset included in the higher layer parameter SRS-ResourceSet as in the operation of Rel-15 / 16, or can be dynamically determined by using a new offset as in Example 2-1.

[0428] Fig.13 It is shown that a UE according to an embodiment dynamically exchanges timing by using an offset indicating two AP SRS resource sets.

[0429] refer to Fig.13 , an operation of exchanging the transmission timing of an AP SRS that requires reordering will be described. In order to exchange the transmission timing of SRS resource sets indicated by two different AP SRS set IDs, the BS may send a DCI including an SRS resource set ID pair to the UE, the SRS resource set ID pair including two SRS resource set IDs for exchanging the transmission timing. An offset of the SRS resource set ID pair indicating the AP SRS whose transmission timing is to be exchanged may be indicated by a DCI independent of a DCI including an SRS request field for triggering the AP SRS, and the independent DCI may be sent at a later time than the DCI including the SRS request field. Reference Fig.13, the UE can exchange the transmission timing of the two AP SRS resource sets 13-5 and 13-15 by referring to the SRS resource set ID pair indicated by the received DCI 13-10. That is, the UE can change the transmission timing of the two AP SRS resource sets 13-5 and 13-15 to the transmission timing of the two AP SRS resource sets 13-20 and 13-25. When the indicated SRS resource set includes a plurality of SRS resources, the transmission timing of the included resources can be changed.

[0430] Fig.14 It is shown that the UE according to the embodiment dynamically exchanges the transmission timing of two AP SRS resource sets and delays the transmission timing of the AP SRS resource sets by using information indicating the two AP SRS resource sets and the timing delay offset.

[0431] refer to Fig.14 , an operation of exchanging and automatically delaying AP SRS transmission timing will be described. The BS may send a DCI 14-10 including an SRS resource set ID pair and a delay offset indicating a timing delay to the UE, the SRS resource set ID pair including two SRS resource set IDs whose transmission timing is to be exchanged. The DCI including the SRS resource set ID pair and the delay offset of the AP SRS whose transmission timing is to be exchanged may be indicated by a DCI independent of the DCI including the SRS request field for triggering the AP SRS, and the independent DCI may be sent at a later time than the DCI including the SRS request field. As an example of this operation, Fig.14 An operation of exchanging the transmission timing of two AP SRS resource sets 14-5 and 14-15 and delaying the transmission timing by the indicated delay offset is shown. When the UE receives the DCI 14-10 including the SRS resource set ID pair and the timing delay offset, the UE can change the transmission timing of the two AP SRS resource sets 14-5 and 14-15 to the transmission timing of the two AP SRS resource sets 14-20 and 14-25. In addition, based on the exchanged AP SRS transmission timing, the UE can automatically delay the transmission timing of all AP SRS resource sets 14-20, 14-30, 14-35 and 14-25 by the indicated delay offset (for example, the delay offset is 2), and these AP SRS resource sets 14-20, 14-30, 14-35 and 14-25 will be transmitted after the time slot n+3 including the first transmitted AP SRS resource set ID.

[0432] Fig.15 It is shown that a UE according to an embodiment dynamically reorders the transmission timing of three or more AP SRS resource sets by using an offset that reorders the order of triggered SRS resources.

[0433] refer to Fig.15 , the operation of overriding the transmission timing will be described. The BS can reorder the order of the triggered AP SRS resource set IDs, and can send the reordered AP SRS resource set ID list to the UE through DCI 15-5. This method can be used to exchange three or more AP SRS transmission timings. The reordered AP SRS resource set ID list can be represented as an APSRS resource set ID, whose transmission timing will be sequentially exchanged based on the pre-configured transmission timing.

[0434] Fig.15 An example of generating a reordered AP SRS resource set ID list is shown. The DCI including the reordered AP SRS resource set ID list for exchanging transmission timing may be indicated by a DCI independent of the DCI including the SRS request field for triggering AP SRS, and the independent DCI may be sent at a later time than the DCI including the SRS request field. The UE may receive DCI 15-5 for reordering AP SRS resource sets 15-10, 15-15, 15-20, and 15-25, and may reorder the transmission timing of SRS resource sets 15-30, 15-35, and 15-40, and may cancel the transmission of SRS resource set 15-45. When the number of all triggered AP SRS resource sets is M, the number of bits used to indicate the AP SRS resource set ID whose transmission timing is to be exchanged may be defined as The UE may reorder all SRS transmission timings by mapping the preconfigured AP SRS transmission timings to the AP SRS resource set IDs indicated by the DCI. In this case, when there is 0 (e.g., 0 in the IDs in the list, a negative number, or an ID not present in the list) in the SRS resource set ID list for reordering based on the DCI instead of the AP SRS resource set ID whose transmission timing is to be exchanged, SRS transmission of the AP SRS resource set may be canceled.

[0435] By considering the minimum time interval K according to the usage and the time slot n' at which the PDCCH including the DCI indicating the reordering is received (K=N when the usage of AP SRS is set to "codebook" or "antennaSwitching") 2 symbols (PUSCH preparation time), and K = N in other cases 2 +14 symbols), the AP SRS transmission timing of the first transmitted AP SRS in the reordered AP SRS resource set in the above method should be greater than n'+K. When the AP SRS transmission timing is not greater than n'+K, the AP SRS can be transmitted by applying the automatic delay method or the offset control method described below, or the corresponding indication can be ignored.

[0436] Embodiment 2-4 : How to cancel the triggered AP SRS

[0437] In Embodiment 2-4, an operation in which the BS transmits an additional DCI for cancelling the triggered AP SRS to the UE so as not to transmit the triggered AP SRS and the UE cancels the triggered AP SRS according to the received additional DCI will be described.

[0438] When the triggered AP SRS transmission is no longer needed, for example, when the purpose of the AP SRS is invalid or the operation related to transmission / reception is changed, the BS can send information for canceling the unnecessary AP SRS to the UE. For example, when the BWP is changed after the AP SRS is triggered and before the corresponding resource is sent, information for the UL channel of the changed BWP may be needed instead of the UL channel of the BWP to be estimated using the triggered AP SRS. In this case, the AP SRS resource set triggered before the BWP is changed should be canceled, and a new AP SRS resource set for the changed BWP should be triggered. When the purpose of the AP SRS is invalid or the operation related to transmission / reception is changed, the triggered AP SRS may need to be canceled when a DL signal should be urgently received in the time slot where the AP SRS is triggered or another UL signal should be urgently sent. The operation according to the method of canceling the triggered AP SRS can be defined as follows. Reference will be made to Figures 16 to 18 Operations according to the method of cancelling triggered AP SRS are described.

[0439] Fig.16 It is shown that a UE according to an embodiment dynamically cancels a single AP SRS resource set by using an offset for canceling a single triggered SRS resource set.

[0440] refer to Fig.16 , an operation for canceling a single AP SRS resource set (per UE AP SRS dropping) will be described. In order to cancel a specific AP SRS, the BS may send a DCI 16-10 including the AP SRS resource set ID to be canceled to the UE. In order to cancel a specific AP SRS, the BS may send a DCI 16-10 including an offset p to the UE. The offset p may be indicated by a DCI that is the same as the AP SRS resource set ID to be canceled. As shown in the following example, the AP SRS resource set ID to be canceled indicated by the DCI may be omitted.

[0441] After the UE receives the PDCCH including the DCI 16-10 indicating the cancellation of the triggered AP SRS in time slot n' (e.g., n'=n+1), the UE can cancel the triggering of the corresponding AP SRS resource set. In this case, n' can be set to a value greater than the time point n when the DCI including the SRS request field for triggering the AP SRS to be canceled is received. Fig.16 An operation of canceling a single triggered AP SRS resource set 16-5 is shown. In detail, when the offset p is 2, based on the DCI 16-10, the UE can cancel the AP SRS triggered in the time slot n+3 corresponding to n'+p. When multiple AP SRS resource sets are triggered to be sent in the time slot n+3, the UE can cancel the AP SRS resource set according to the AP SRS resource set ID indicating the AP SRS resource set to be canceled. When a single AP SRS resource set is triggered to be sent in the time slot n+3, the AP SRS resource set ID indicating the AP SRS resource set to be canceled can be omitted.

[0442] When the minimum time interval is K (when the AP SRS usage is set to "codebook" or "antennaSwitching"), K = N 2 symbols (PUSCH preparation time) and in other cases K = N 2 +14 symbols), the cancelled AP SRS transmission timing should be greater than n'+K. When the cancelled AP SRS transmission timing is not greater than n'+K, the corresponding indication can be ignored.

[0443] Fig.17 It is shown that a plurality of UEs according to an embodiment cancel a triggered AP SRS resource set by using an offset for canceling a group-based triggered AP SRS resource set.

[0444] refer to Fig.17 , an operation for canceling an AP SRS resource set transmitted in a specific time slot (grouped APSRS discard) will be described. In order to cancel the AP SRS transmitted in a specific time slot, the BS may transmit a DCI 17-0 including a time slot offset p for canceling the AP SRS transmission to the UE. After the UE receives a PDCCH including a DCI 17-0 for canceling the AP SRS transmission in time slot n', all AP SRS resource sets transmitted in time slot n'+p may be canceled in consideration of the time slot n' at which the PDCCH is received and the time slot offset p indicating the cancellation.

[0445] Fig.17The operation of multiple UEs canceling AP SRS resource sets 17-15 and 17-20 by using the offset p included in the DCI 17-0 is shown, and the offset p is used to cancel the triggered AP SRS resources 17-5 and 17-10 of the UEs (UE1 to UE3) in the group. Fig.17 , when the time slot for receiving DCI 17-0 is time slot n+1 and the offset p is 2, n'+p may be n+3, so all AP SRS 17-5 and 17-10 transmitted in time slot n+3 of the UEs (UE1 to UE3) within the group may be canceled (17-15 and 17-20).

[0446] When the minimum time interval is K (when the AP SRS usage is set to "codebook" or "antennaSwitching"), K = N 2 symbols (PUSCH preparation time) and in other cases K = N 2 +14 symbols), indicating that n'+p of AP SRS cancellation should be greater than n'+K. When n'+p is not greater than n'+K, the corresponding indication can be ignored.

[0447] Fig.18 It is shown that the UE according to an embodiment cancels all triggered AP SRS resource sets after the indicated time slot.

[0448] refer to Fig.18 , an operation for canceling all triggered AP SRS after slot m will be described. In order to cancel all AP SRS transmitted after a specific slot, the BS may transmit DCI 18-0 including slot offset m for canceling AP SRS transmission to the UE.

[0449] After the UE receives a PDCCH including DCI 18-0 for canceling AP SRS transmission in time slot n' (here, time slot n+1), considering the time slot n' in which the PDCCH is received and the time slot offset m indicating the cancellation, the UE can cancel all AP SRS resource sets transmitted in time slots after n'+m (here, n+3).

[0450] Fig.18 The operation of deactivating all AP SRS resource sets 18-5, 18-10, 18-15, and 18-20 after the indicated time slots (18-25, 18-30, 18-35, and 18-40) is shown.

[0451] When the minimum time interval is K (when the AP SRS usage is set to "codebook" or "antennaSwitching"), K = N 2symbols (PUSCH preparation time) and in other cases K = N 2 +14 symbols), n'+m indicating the cancellation of all AP SRS should be greater than n'+K. When n'+p is not greater than n'+K, the corresponding indication can be ignored, or all AP SRS triggered in the time slot after n'+K can be cancelled.

[0452] Embodiment 2-5 : AP SRS management method based on UE capability triggering

[0453] There may be restrictions in the periodic SRS resource sets that can be triggered by the UE according to the UE capabilities. For example, when AP SRS is triggered by using a flexible trigger offset as in Example 2-1, the UE can manage multiple different AP SRS resource sets that are dynamically triggered. In this case, the UE should store the configuration information in a restricted resource (e.g., a memory for triggered APSRS management) until UL transmission is performed for the triggered AP SRS resource set. Therefore, the configuration information that can be stored by the UE may be limited according to the UE capabilities.

[0454] When AP SRS is triggered as much as the maximum configuration information that the UE can store, the UE can ignore the AP SRS information that is triggered additionally thereafter. Alternatively, after AP SRS is triggered as much as the maximum configuration information that can be stored, the UE can notify the BS via a UL transmission channel such as PUCCH or PUSCH that the maximum manageable AP SRS triggering has been reached.

[0455] Example 3 :AP SRS transmission method based on automatic delay triggering

[0456] When the AP SRS is sent by using the slotOffset in the higher layer parameter SRS-ResourceSet or triggered according to Embodiment 2, the UE may not use UL resources to perform SRS transmission at the AP SRS transmission timing. The operation of triggering and sending the AP SRS will be described in detail. The UE may trigger the AP SRS according to the SRS request field indicated by the DCI, and the transmission timing of the triggered APSRS may be semi-statically determined by the slotOffset in the higher layer parameter SRS-ResourceSet defined in Rel-15 / 16. Alternatively, the UE may trigger the AP SRS according to the SRS request field indicated by the DCI, and the transmission timing of the triggered AP SRS may be dynamically determined using the new offset indicated by the DCI as in Embodiment 2. As in the following example, there may be a situation where the triggered AP SRS cannot be sent at the determined transmission timing. For example, when the AP SRS overlaps with UL physical channel information having a higher priority than the AP SRS transmission, the UE may not send the AP SRS of the overlapping symbols, and may discard the unsent SRS. To prevent the triggered AP SRS from being discarded, the transmission timing may be adjusted as described in Embodiment 2. However, when the transmission timing is adjusted by using this method, the BS transmits additional DCI, thereby increasing DCI overhead. In this case, additional DCI is transmitted to indicate a new offset for dynamically determining the transmission timing.

[0457] To remedy this problem, the present disclosure provides an AP SRS transmission method based on automatic delay triggering. By using the AP SRS transmission method based on automatic delay triggering of the current embodiment of the present disclosure, the discarded AP SRS can be transmitted without additional DCI or with very small additional DCI. The AP SRS transmission method based on automatic delay triggering will be described in more detail in Example 3-1, Example 3-2, and Example 3-3.

[0458] Example 3-1 : AP SRS transmission method using automatic delay

[0459] When the UE cannot send the AP SRS at the determined transmission timing, the BS can receive a report on the UE capability for automatic delay to determine whether the AP SRS can be sent by performing automatic delay. When the UE sends a report on the UE capability and can support automatic delay, the BS can add a high-level parameter during RRC configuration, such as "enableAutoDelay", which is used to determine whether to perform the automatic delay operation, and the value can be set to {on}. The UE receives the RRC configuration information from the BS. The UE can determine the AP SRS to be sent based on the above-mentioned AP SRS triggering operation. When the UE cannot send the APSRS at the determined AP SRS transmission time, the UE can send the AP SRS by referring to Fig.19 The described automatic delay method sends the AP SRS on the available physical resources.

[0460] Fig.19 It is shown that the UE according to the embodiment transmits the AP SRS by using the automatic delay method.

[0461] Reference Fig.19 , the UE determines whether the AP SRS can be transmitted at the triggered transmission timing based on whether the UL transmission of the physical resources is configured and whether the UL transmission of another physical channel information is required. For example, when the UE cannot transmit the AP SRS at the triggered transmission timing (19-05 and 1-20), the UE can automatically delay the transmission timing until the AP SRS can be transmitted on the available physical resources (19-10 and 19-30).

[0462] As described in Embodiment 2, even when the timing of triggering and sending AP SRS does not meet the required time 19-25 including the processing time of SRS sending (19-20), the UE can send AP SRS on the next available physical resource 19-30 through automatic delay of an embodiment of the present disclosure.

[0463] Example 3-2 : AP SRS sending method indicating available resource index

[0464] The BS can trigger the AP SRS through DCI, and can semi-statically determine the transmission timing of the AP SRS by using a higher layer parameter slotOffset as in Rel-15 / 16, or can dynamically determine the transmission timing as in the method of Example 2. However, when the triggered AP SRS cannot be transmitted at the indicated timing, the UE can discard the triggered AP SRS as in the Rel-15 / 16 operation, or can automatically delay the triggered AP SRS until the next AP SRS transmittable resource as in the method of Example 3-1. Because the method of Example 3-1 only performs automatic delay until the next transmittable resource, it is difficult to flexibly manage the transmission resources of multiple triggered AP SRSs. Therefore, Example 3-2 provides an automatic delay method through an available resource index indicated by DCI to flexibly support the automatic delay method. An available resource index u can be sent instead of a time slot index, and the available resource index u indicates the uth transmittable resource (e.g., time slot) among the resources (e.g., time slot) on which the AP SRS can be transmitted.

[0465] When the UE is unable to send the AP SRS at the determined transmission timing, the BS may receive a report of the UE capabilities to determine whether automatic delay can be performed by considering the available resource index indicated by the DCI. When the UE sends a report of the UE capabilities and can support automatic delay considering the available resource index, the BS may add a higher layer parameter during the RRC configuration, such as "enableAutoDelayResourceIndex", which is used to determine whether to perform the automatic delay operation by considering the available resource index, and the value may be set to {on}. This is an example of a higher layer parameter configuration method, and a higher layer parameter, such as "enableAutoDelay" described in Example 3-1, may be added, and the value may be set to {ResourceIndex} to distinguish it from Example 3-1. When the UE is unable to send the AP SRS at the determined AP SRS transmission time, as described in reference to Fig. 20 As described above, the UE may transmit the AP SRS by performing automatic delay based on the available resource index indicated by the DCI.

[0466] Fig. 20 It is shown that the UE according to an embodiment sends an AP SRS based on the indicated available resource index.

[0467] Reference Fig. 20, the BS may indicate the available resource index to adjust the transmission timing of the newly triggered or already triggered AP SRS. When the BS indicates the available resource index of the newly triggered AP SRS, the BS may indicate the available resource index by using an additional field in the DCI used to trigger the AP SRS. In this case, the available resource index may be applied to the AP SRS resource set triggered by the transmitted DCI. Alternatively, the BS may indicate the available resource index of the already triggered AP SRS through a DCI independent of the DCI used to trigger the AP SRS. In this case, the SRS resource set ID field in the DCI may be added to indicate the AP SRS to which the available resource index is applied. The term "available resource index" refers to an index corresponding to an available resource.

[0468] For example, refer to Fig. 20 , when the UE receives a DCI in which the available resource index u 20-0 is set to 1 (u=1), the UE may perform an automatic delay until AP SRS 20-05 is sent on the first available resource (20-10). When the UE receives a DCI in which the available resource index u 20-15 is set to 2 (u=2), the UE may automatically delay and may send AP SRS 20-20 on the second available resource (20-25). Similarly, when the UE receives a DCI in which the available resource index u 20-30 is set to 3 (u=3), the UE may automatically delay and send AP SRS 20-35 on the third available resource (20-40).

[0469] The BS can instruct the UE to perform the operation defined in the embodiment of the present disclosure by using the same index u for all triggered AP SRS resource sets. Alternatively, the BS can indicate each index u of each AP SRS resource set that has been triggered or newly triggered by DCI, and can indicate the SRS to be sent on different available resources. That is, the index u can be configured according to each AP SRS resource set. When the UE receives a DCI from the BS in which the index u 20-45 is set to 0 (u=0) for the triggered AP SRS resource set, the UE can cancel the AP SRS resource set (20-50).

[0470] Example 3-3 : A method of sending AP SRS using overlapping available resources due to automatic delay.

[0471] Fig.21 It shows a rule for the UE to select the AP SRS resource set to be transmitted preferentially when the transmission timings of the automatically delayed AP SRS resource set and the newly triggered AP SRS resource set are the same and the AP SRS resource sets cannot be transmitted at the same time according to an embodiment.

[0472] Fig. 22 A rule for a UE to select an AP SRS resource set to be transmitted preferentially when the transmission timings of two AP SRS resource sets triggered based on available indexes are the same and the AP SRS resource sets cannot be transmitted simultaneously according to an embodiment of the present invention is shown.

[0473] refer to Fig.21 and 22 , a method of selecting an AP SRS resource set to be transmitted preferentially when two or more AP SRS resource sets cannot be transmitted at the same transmission timing will be described.

[0474] refer to Fig.21 , the available resources of the automatically delayed AP SRS resource set 21-10 and another AP SRS resource set 21-20 may overlap with each other. When the BS and the UE operate as in the method of embodiment 3-1, as Fig.21 As shown, AP SRS resource set 0 21-5 and 21-35 triggered in time slot n+1 can be automatically delayed (21-10 and 21-40) to time slot n+3. In addition, AP SRS resource set 1 can be triggered in time slot n+3 as the available resource timing (21-20 and 21-50). In this case, two different AP SRS resource sets 0 and 1 can overlap each other at the same transmission timing (i.e., time slot n+3). Alternatively, when the BS and the UE operate as in the method of embodiment 3-2, as shown in Fig. 22 As shown, when the index u is set to 1 for AP SRS resource sets 0 and 1 (22-0, 22-15, 22-35, and 22-50), two different AP SRS resource sets 0 and 1 can be transmitted at the same transmission timing u. 1 (=time slot n+3) (22-10, 22-25, 22-45 and 22-60) overlap each other. When the overlapping AP SRS resource sets 0 and 1 cannot be sent at the same transmission timing, the following rules can be used to select the time slot u 1 The AP SRS resource set sent in.

[0475] -1) The UE preferentially sends the AP SRS resource set triggered earlier among multiple overlapping AP SRS resource sets (21-40 and 22-45), and automatically delays the AP SRS resource set triggered later (21-55 and 22-65), and sends the AP SRS resource set on the next available resource or cancels the AP SRS resource set.

[0476] -2) The UE preferentially sends the AP SRS resource set that is triggered later among multiple overlapping AP SRS resource sets (21-20 and 22-25), and automatically delays the AP SRS resource set that is triggered earlier (21-25 and 22-30), and sends the AP SRS resource set on the next available resource or cancels the AP SRS resource set.

[0477] When the AP SRS resource set is automatically delayed and continues to be delayed until the Xth time slot set as the threshold, the UE may cancel the AP SRS resource set.

[0478] Example 4 : How to configure the information sending of dynamic triggering AP SRS

[0479] In Embodiment 4, a method of configuring a new offset field in DCI to indicate a new offset for dynamically determining the transmission timing of AP SRS will be described. According to the above-mentioned embodiments of the present disclosure, the BS may indicate a new offset based on the DCI to determine the transmission timing of the AP SRS. In this case, the field for the new offset in the DCI may be configured differently according to the method for dynamically determining the transmission timing of the AP SRS and the RRC information configured based on the UE capability reported by the UE. When the UE may support operations according to at least one of the above-mentioned embodiments of the present disclosure and receives an RRC configuration from the BS to support the operation, the BS may indicate the operation to be performed using the new offset indicated by the DCI.

[0480] When the BS should indicate the AP SRS resource set for dynamically determining the transmission timing by applying the offset indicated by the DCI, a field for indicating the AP SRS resource set ID for dynamically determining the transmission timing should be added to the DCI. The BS may determine that the ID of the AP SRS resource set for dynamically determining the transmission timing should be indicated by using an additional DCI field when all of the following conditions are met:

[0481] -1) When the transmission timing of the triggered AP SRS is determined by an additional DCI independent of the DCI including the SRS request field for triggering the AP SRS

[0482] -2) When multiple AP SRS resource sets are triggered

[0483] -3) When the transmission timing of the AP SRS is determined by "registration", "adjustment" or "automatic delay considering the available resource index" in the operations described in the above embodiments of the present disclosure, or when a specific triggered AP SRS resource set is canceled by an operation for canceling a single AP SRS resource set

[0484] When a new offset is indicated by the same DCI as the SRS request field, the transmission timing can be determined by applying the new offset to the AP SRS resource set triggered by the DCI. In the "reordering" in the operation described in the above-mentioned embodiment of the present disclosure, since the AP SRS resource set ID pair (three or more IDs) for exchanging the transmission timing is sent by using the new offset, a field for indicating a separate AP SRS resource set ID is not required. In the "cancel" operation excluding the operation for canceling a single AP SRS resource set, since the position of the time slot for canceling the transmission is indicated, a field for indicating a separate AP SRS resource set ID is not required.

[0485] Therefore, when the BS indicates a new offset for dynamically determining the transmission timing of the AP SRS through the DCI, the DCI for indicating the new offset may include 1) a main operation field, 2) a detailed operation field, 3) an AP SRS resource set ID field for performing the operation, and 4) a new offset field according to the RRC configuration according to the UE capability of the UE and the transmission timing change operation to be indicated. In this case, some fields may be omitted according to the RRC configuration and the transmission timing change operation to be indicated.

[0486] Fig.23a A method according to an embodiment is shown, by which a BS configures a DCI for dynamically triggering an AP SRS. Specifically, Fig.23a A method of configuring DCI when an ID field of an AP SRS resource set for dynamically determining a transmission timing is not added is shown.

[0487] In order to dynamically trigger the AP SRS, a new trigger may be performed by using DCI, or the information of the triggered AP SRS resource set may be updated as described above. In this case, the operation for determining the AP SRS transmission timing and the offset required for each operation may be transmitted through DCI. The DCI according to the embodiment may be divided into three fields, such as Fig.23a shown.

[0488] Reference Fig.23a , the first DCI field 23-05 may indicate a main operation method for determining the timing of the AP SRS, such as "registration", "adjustment", "cancellation" and "automatic delay" in the above-mentioned embodiments of the present disclosure. When the BS selects only one of the operations such as "registration", "adjustment", "cancellation" and "automatic delay" and supports AP SRS triggering, the first DCI field may be omitted, and when only one of its detailed operations is used, the second DCI field 23-10 may be omitted to form the DCI.

[0489] The second DCI field 23-10 may indicate a detailed operation method of the operation method selected in the first DCI field, or the second DCI field 23-10 may be omitted when the selected operation method is defined by only one detailed operation and the transmission timing of the AP SRS is determined. For example, when a new offset is received, the second DCI field 23-10 may indicate whether only the received offset is applied or the new offset and the offset determined based on the higher layer are applied together. When a new offset is received and it is agreed that only the new offset is applied, the second DCI field 23-10 may be omitted because an indication of a detailed operation is not required. As in the above-mentioned DCI field configuration method, by considering the UE capability, it may be determined whether to omit the first DCI field and the second DCI field according to the RRC information configured by the BS.

[0490] In the third DCI field 23-15, an offset required for determining the transmission timing of the AP SRS according to the dynamic AP SRS triggering operation previously determined between the BS and the UE or determined by the first DCI field 23-05 and the second DCI field 23-10 may be indicated, and the offset may be omitted for an operation that does not require an additional offset. The offset included in the third DCI field 23-15 may be set to a value for relatively indicating the SRS transmission timing according to the dynamic AP SRS triggering operation (relative time slot offset), a value for directly indicating the SRS transmission timing (absolute time slot offset), or an AP SRS transmittable resource index (available resource index). Examples of the offset included in the third DCI field 23-15 may be shown in Tables 17, 18, and 19, and are respectively a value for relatively indicating the SRS transmission timing, a value for directly indicating the SRS transmission timing, and an available resource index.

[0491] Table 17

[0492] DCI value 0 1 … <![CDATA[2 A -2]]> <![CDATA[2 A -1]]> Indicative value <![CDATA[-2 A / 2+1]]> <![CDATA[-2 A / 2+2]]> … <![CDATA[2 A / 2-1]]> <![CDATA[2 A / 2]]>

[0493] Table 18

[0494] DCI value 0 1 … <![CDATA[2 B -2]]> <![CDATA[2 B -1]]> Indicative value 1 2 … <![CDATA[2 B -1]]> <![CDATA[2 B ]]>

[0495] Table 19

[0496] DCI value 0 1 … <![CDATA[2 C -2]]> <![CDATA[2 C -1]]> Indicative value 1 2 … <![CDATA[2 C -1]]> <![CDATA[2 C ]]>

[0497] The BS can configure and indicate the APSRS resource set ID for performing "reordering" by using a new offset in the third DCI field. According to the reordering method, {SRS resource set ID pair}, {SRS resource set ID pair and timing delay offset}, or {three or more SRS resource set IDs} can be indicated by using a new offset for performing reordering.

[0498] Figure 23b A method according to an embodiment is shown, by which a BS configures a DCI for dynamically triggering an AP SRS.

[0499] exist Figure 23b In the example, the AP SRS resource set ID field 23-20 may be added to the reference Fig.23a The DCI configuration described in the specification indicates the ID of the AP SRS resource set used to dynamically determine the transmission timing. Figure 23b The information indicated by the first to third DCI fields 23-05 to 23-15 can be Fig.23a The information indicated by the first to third DCI fields 23-05 to 23-15 is the same.

[0500] Example 5: AP SRS triggering method based on group DCI

[0501] The BS may trigger the AP SRS to the UE through a UE-specific DCI (such as DCI format 0 1 or 1 1), or may trigger the AP SRS for one or more UEs at the same time through a group-common DCI. When the AP SRS is triggered through the group-common DCI, the DCI overhead required to trigger the AP SRS for each UE may be reduced. The group-common DCI for triggering the AP SRS may use the format of an existing UE group, such as DCI format 23. When the BS dynamically triggers the AP SRS for a single group by using DCI format 23, the higher-layer parameter srs-TPC-PDCCH-Group may be set to typeA or typeB, and the configuration method of the DCI format 2_3 may change according to the type. When the higher-layer parameter srs-TPC-PDCCH-Group is set to typeA, a block may be configured to include the following fields.

[0502] -SRS Request

[0503] -TPC command No. 1, TPC command No. 2, ..., TPC command No. N

[0504] -AP SRS trigger information

[0505] The AP SRS trigger information refers to a new offset field used to dynamically determine the transmission timing of the AP SRS. The new offset field may be the same as the DCI configuration method of the fourth embodiment.

[0506] When the higher layer parameter srs-TPC-PDCCH-Group is set to typeB, each block corresponding to block No. 1, block No. 2, ... block No. B may be configured to include the following fields.

[0507] -SRS Request

[0508] -TPC Command

[0509] -AP SRS trigger information

[0510] The AP SRS trigger information refers to a new offset field used to dynamically determine the transmission timing of the AP SRS. The new offset field may be the same as the DCI configuration method of the fourth embodiment.

[0511] Alternatively, when the higher layer parameter srs-TPC-PDCCH-Group is set to typeB, DCI format 2_3 may be configured to include block No. 1, block No. 2, ... block No. B, SRS offset block 1, ... SRS offset block C by adding a block including AP SRS trigger information. Each SRS offset block may include AP SRS trigger information, and the number C of SRS offset blocks may be different from B. The AP SRS trigger information defined in this embodiment of the present invention may constitute the DCI described in Embodiment 4.

[0512] Fig.24 is a flowchart of a process in which a UE triggers an AP SRS by considering higher layer parameters and a DCI-based dynamic AP SRS triggering offset according to an embodiment.

[0513] refer to Fig.24 , the UE can perform DCI-based dynamic AP SRS triggering as in the above embodiments.

[0514] Before executing step 24-05, the UE may send UE capabilities to the BS to report whether the AP SRS transmission timing is dynamically variable.

[0515] In steps 24-05 and 24-10, based on the RRC configuration information of the SRS resource set, the UE receives DCI format 0_1, 1_1 or 2_3 for triggering AP SRS. This DCI format is only an example, and the information for dynamically triggering AP SRS can be sent in another DCI format 0_2 or 1_2 or a new DCI format. The RRC configuration received in step 24-05 may include a higher layer parameter SRS-ResourceSet and a higher layer parameter for supporting dynamic timing changes of AP SRS according to the reported UE capabilities. SRS-ResourceSet includes Rel-15 / 16aperiodicSRS-ResourceTrigger (aperiodicSRS-ResourceTriggerList when present) and slotOffset.

[0516] In step 24-15, the UE checks the SRS request field for the AP SRS triggering status.

[0517] In step 24-20, the UE determines whether the SRS request field is set to 00 among 00, 01, 10, and 11. When the SRS request field is set to 00, in operation 24-40, the UE determines that the AP SRS resource set is not triggered.

[0518] In steps 24-25, the UE determines whether a new offset for dynamically triggering the AP SRS is received.

[0519] In step 24-30, when no new offset is received, the UE may trigger the APSRS resource set configured by the higher layer parameters. When a new offset is received, in step 24-35, the UE may update the AP SRS transmission timing to the new offset by considering the new offset, and may trigger the AP SRS. In this case, the higher layer parameters may or may not be considered. The UE may perform an operation for dynamically determining the transmission timing, such as timing adjustment, reordering, cancellation, or automatic delay, according to the available resource index of the triggered AP SRS.

[0520] Fig.25 is a flowchart illustrating a process in which a UE transmits an AP SRS by considering a DCI for dynamically determining a transmission timing of an AP SRS resource set according to an embodiment.

[0521] refer to Fig.25 Before executing step 25-05, the UE may send UE capabilities to the BS to report whether the AP SRS transmission timing is dynamically variable.

[0522] When the UE is able to dynamically change the AP SRS transmission timing, in step 25-05, the UE reports to the BS whether the adjustment, reordering, and cancellation described in Embodiments 2-2, 2-3, and 2-4 and the automatic delay described in Embodiment 3 are supported.

[0523] In step 25-05, trigger the AP SRS resource set.

[0524] In step 25-10, the UE determines whether DCI format 0_1, 1_1 or 2_3 for dynamically triggering AP SRS is received. The DCI format is just an example, and information for dynamically triggering AP SRS can be sent in another DCI format. Examples of other DCI formats may include 0_2, 1_2 and new DCI formats.

[0525] When the UE receives a DCI format for dynamically triggering the AP SRS, the UE performs adjustment, reordering, cancellation, or automatic delay on the AP SRS in one of steps 25-15 to 25-30. These operations can be performed in parallel for different AP SRSs, and a certain operation (e.g., adjustment) can be performed for one AP SRS, and then another operation (cancellation) can be performed.

[0526] In step 25-35, the UE updates the triggered SRS resource set based on at least one of steps 25-15 to 25-30.

[0527] In step 25-40, when the UE does not receive the DCI for dynamically triggering the AP SRS, the UE may determine whether a UL resource for sending a triggered AP SRS resource set is available.

[0528] When UL resources are available for transmitting the AP SRS, in step 25-45, the UE determines whether a plurality of AP SRS resource sets are triggered to be transmitted at the UL transmission timing.

[0529] When a plurality of AP SRS resource sets are triggered to be transmitted at the same UL transmission timing, in step 25-50, the UE determines whether the plurality of AP SRS resource sets can be transmitted at the same UL transmission timing.

[0530] When a plurality of AP SRS resource sets cannot be simultaneously transmitted at the same UL transmission timing, in step 25-55, the UE determines a priority rule for each AP SRS resource set.

[0531] When a single AP SRS resource set is triggered at the UL transmission timing in step 25-45, the AP SRS resource sets triggered in step 25-50 can be simultaneously transmitted at the UL transmission timing, or the priority of the AP SRS resource set is high in step 25-55, the UE transmits the AP SRS in step 25-60.

[0532] When the UE cannot send the triggered AP SRS resource set through UL resources in step 25-40 or the priority of the AP SRS resource set is low in step 25-55, the UE may perform automatic delay until finding available UL resources in step 25-65.

[0533] Fig.26 A terminal according to one embodiment is shown.

[0534] refer to Fig.26The terminal includes a transmitter 26-10, a receiver 26-00, and a processing unit 26-05 including a memory and a processor. According to the communication method of the terminal described above, the transmitter 26-10, the receiver 26-00, and the processing unit 26-05 of the terminal can operate. However, the elements of the terminal are not limited thereto. For example, the terminal may include Fig.26 More or fewer elements are shown. The transmitter 26-10, the receiver 26-00 and the processing unit 26-05 may be implemented as one chip.

[0535] The transmitter 26-10 and the receiver 26-00 can send signals to the BS and receive signals from the BS. The signal may include control information and data. To this end, the transmitter 26-10 and the receiver 26-00 may include a radio frequency (RF) transmitter that up-converts and amplifies the frequency of the transmitted signal and an RF receiver that low-noise amplifies the received signal and down-converts the frequency. However, they are only examples, and the elements of the transmitter 26-10 and the receiver 26-00 are not limited to the RF transmitter and the RF receiver.

[0536] The transmitter 26 - 10 and the receiver 26 - 00 may receive a signal through a wireless channel and may output a signal to the processing unit 26 - 05 and may transmit a signal output from the processing unit 26 - 05 through a wireless channel.

[0537] The processing unit 26-05 may store programs and data required for the terminal operation. The processing unit 26-05 may store control information or data included in the signal obtained from the terminal. The processing unit 26-05 may include a memory including a storage medium such as a read-only memory (ROM), a random access memory (RAM), a hard disk, a compact disk-ROM (CD-ROM) or a digital versatile disk (DVD) or a combination thereof.

[0538] The processing unit 26-05 may control a series of processes so that the terminal operates according to the above-mentioned embodiment.The processing unit 26-05 may control the elements of the terminal to simultaneously receive multiple PDSCHs by receiving DCI including two layers.

[0539] Fig. 27 A BS according to one embodiment is shown.

[0540] refer to Fig. 27 , the BS includes a transmitter 27-10, a receiver 27-00, and a processing unit 27-05 including a memory and a processor. According to the communication method of the BS described above, the transmitter 27-10, the receiver 27-00, and the processing unit 27-05 can operate. However, the elements of the BS are not limited thereto. For example, the BS may include Fig. 27More or fewer elements are shown. The transmitter 27-10, the receiver 27-00 and the processing unit 27-05 may be implemented as one chip.

[0541] The transmitter 27-10 and the receiver 27-00 can send signals to and receive signals from the terminal. The signal may include control information and data. To this end, the transmitter 27-10 and the receiver 27-00 may include an RF transmitter that up-converts and amplifies the frequency of the transmitted signal, and an RF receiver that low-noise amplifies the received signal and down-converts the frequency. However, they are only examples, and the elements of the transmitter 27-10 and the receiver 27-00 are not limited to the RF transmitter and the RF receiver.

[0542] The transmitter 27-10 and the receiver 27-00 may receive a signal through a wireless channel and may output a signal to the processing unit 27-05, and may transmit a signal output from the processing unit 27-05 through a wireless channel.

[0543] The processing unit 27-05 may store programs and data required for BS operation. The processing unit 27-05 may store control information or data included in a signal obtained from the BS. The processing unit 27-05 may include a memory including a storage medium such as a ROM, RAM, hard disk, CD-ROM, or DVD, or a combination thereof.

[0544] The processing unit 27-05 may control a series of processes so that the BS operates according to the above-described embodiments.The processing unit 27-05 may configure DCI including allocation information for PDSCH, and may control each element of the BS to transmit the DCI.

[0545] Fig.28 is a flowchart illustrating an operation method of a UE according to an embodiment.

[0546] Reference Fig.28 In step 2810, the UE receives configuration information of a UL reference signal based on higher layer signaling. Specifically, the UE may receive DCI including the configuration information of the UL reference signal from the BS. The configuration information of the UL reference signal may be determined by RRC configuration information through higher layer signaling.

[0547] At step 2820, the UE receives a DCI for changing the transmission timing of the UL reference signal. The UE may determine the transmission timing of the UL reference signal based on the configuration information of the UL reference signal. When the UE receives the DCI for changing the transmission timing of the UL reference signal, the UE may change the transmission timing of the UL reference signal based on the received DCI.

[0548] The DCI may be in DCI format 0_1, 1_1, or 2_3, and may include information for adjusting, canceling, reordering, and automatically delaying the transmission timing. The DCI may be configured to apply to a UE group. In this case, the transmission timing of the UL reference signal of the UE group may be collectively changed.

[0549] The UE may transmit a UL reference signal at the transmission timing changed based on the DCI at step 2830. When the DCI is information indicating cancellation of the UL reference signal, the UE may determine not to transmit the UL reference signal.

[0550] Fig.29 is a flowchart illustrating an operation method of a BS according to an embodiment.

[0551] Reference Fig.29 In step 2910, the BS may send configuration information of the UL reference signal based on higher layer signaling. The BS may send DCI including the configuration information of the UL reference signal to the UE. The configuration information of the UL reference signal may be determined by the RRC configuration information through higher layer signaling.

[0552] In step 2920, the BS sends a DCI for changing the transmission timing of the UL reference signal to the UE. Therefore, the UE can determine the transmission timing of the UL reference signal based on the configuration information of the UL reference signal. When the UE receives the DCI for changing the transmission timing of the UL reference signal, the UE can change the transmission timing of the UL reference signal based on the received DCI.

[0553] In this case, the DCI may be sent in DCI format 0_1, 1_1 or 2_3 and may include information for adjusting, cancelling, reordering or automatically delaying the transmission timing. The DCI may be configured to apply to a UE group. In this case, the transmission timing of the UL reference signal of the UE group may be collectively changed.

[0554] The BS receives the UL reference signal at the transmission timing changed based on the DCI in step 2930. When the DCI is information for indicating cancellation of the UL reference signal, the UL reference signal may not be received.

[0555] Example 6 :Operation method for dynamically triggering AP SRS using MAC CE

[0556] The NR system performs AP SRS triggering based on the code point indicated by the DCI and the higher layer configuration. In this case, because the AP SRS is triggered based on a pre-configured SRS resource set, it may be difficult to flexibly trigger the SRS resource set. A more flexible AP SRS triggering can be performed by using a new trigger offset based on DCI or by sharing the additional information required for AP SRS triggering between the BS and the UE based on MAC CE and triggering by DCI. A flexible AP SRS triggering method using MAC CE will be described in Embodiment 6-1, Embodiment 6-2, and Embodiment 6-3. In detail, the flexible AP SRS triggering method using MAC CE may be a method of activating an AP SRS resource set configured in a higher layer based on MAC CE and triggering the AP SRS resource set by DCI, a method of determining the AP SRS transmission timing by using a dynamic AP SRS triggering offset based on MAC CE, or at least one of an AP SRS triggering method based on MAC CE and group DCI. In Embodiment 6-4, a method of flexibly allocating SRS resources and triggering AP SRS by activating SRS resources in an AP SRS resource set by MACCE will be described.

[0557] Example 6-1 :Dynamic AP SRS triggering method using MAC CE-based AP SRS resource set activation

[0558] In the generation operation, the resource set of AP SRS can be triggered by referring to the code point indicated by the DCI and higher layer configuration information. More specifically, all AP SRS resource sets configured by the aperiodicSRS-ResourceTrigger with the same value as the value indicated in the SRS request field in the DCI or the aperiodicSRS-ResourceTriggerList including the value can be triggered. In such a general operation, when AP SRS is triggered and only some of the AP SRS resource sets configured by the aperiodicSRS-ResourceTrigger with the same value as the code point indicated in the SRS request field in the DCI or the aperiodicSRS-ResourceTriggerList including the same value are needed at the triggering time of AP SRS, all AP SRS resource sets indicated by the DCI should be triggered and supported, rather than only some AP SRS resource sets required for UL channel measurement. When it is possible to pre-indicate the activation information of the SRS resource set by using MAC CE, the activated AP SRS resource set can be triggered.

[0559] When the activation information of the MAC CE is configured so that the activated AP SRS resource set only includes the AP SRS resources required at the AP SRS triggering time, a more flexible SRS triggering can be performed than the method of sending all AP SRS resources configured by the DCI. The BS can notify the UE of the activation information of the AP SRS resource set in the SRS resource set list of the higher layer parameter SRS-config through the MAC CE. At the time point of performing the AP SRS triggering, the UE can expect that the code point used for the AP SRS triggering is indicated by the DCI including the SRS request field. When the code point for the AP SRS triggering is indicated by the DCI, the UE can trigger the SRS resource set from the (multiple) AP SRS resource sets activated by the MAC CE, and the aperiodicSRS-ResourceTrigger of the SRS resource set is the same as the code point (SRS request field) indicated by the DCI, or the aperiodicSRS-ResourceTriggerList includes the same value as the code point indicated by the DCI.

[0560] Embodiment 6-1 can be combined with other embodiments of the present disclosure. For example, the BS can combine Embodiment 6-1 with the method of increasing the number of SRS resource sets configured by a higher layer described in Embodiment 1 to indicate activation information of various configured SRS resource sets through MAC CE and support more various trigger combinations for the UE. However, the present disclosure is not limited thereto, and Embodiment 6-1 can be combined with other embodiments to dynamically trigger AP SRS.

[0561] Fig.30 A MAC CE for indicating activation of an AP SRS resource set according to an embodiment is shown.

[0562] Reference Fig.30 , the MAC CE used to indicate the activation of the AP SRS resource set may include the following fields.

[0563] - Cell ID of SRS resource set 30-00: This field indicates the identity of the serving cell including the indicated AP SRS resource set.

[0564] - BWP ID of SRS resource set 30-05: This field indicates the UL BWP including the AP SRS resource set indicated by the codepoint of the DCI bandwidth part indicator field.

[0565] -T i 30-10: This field indicates the AP SR resource set i (SRS Resource Set i ) activation / deactivation state T iIndicates whether the AP SRS resource set is activated, and only the SRS resource set of the AP SRS among all SRS resource sets configured in the higher layer can be mapped to T i For example, when a total of 16 SRS resource sets are configured in a higher layer and an SRS resource set whose srs-ResourceSetId is 1, 3, 5, or 11 is configured as an AP SRS resource set, T 0 Indicates the activation status of the SRS resource set whose srs-ResourceSetId is 1, T 1 Indicates the activation status of the SRS resource set whose srs-ResourceSetId is 3, T 2 Indicates the activation status of the SRS resource set whose srs-ResourceSetId is 5, and T 3 Indicates the activation status of the SRS resource set whose srs-ResourceSetId is 11. Alternatively, all SRS resource sets may be mapped instead of only the SRS resource set of AP SRS, and may be controlled by T i To indicate the activation status of the SRS resource set whose srs-ResourceSetId is i. i The activation of the associated AP SRS resource set can i field is set to 1. To indicate that i The deactivation of the associated AP SRS resource set can i The field is set to 0.

[0566] Example 6-2 :Flexible offset configuration method and dynamic AP SRS triggering method based on MAC CE

[0567] For dynamic AP SRS triggering, the BS can configure a flexible offset for dynamic AP SRS triggering in the UE through MAC CE. The flexible offset and code point for dynamic AP SRS triggering through MAC CE can be mapped. The flexible offset can be determined according to the code point indicated by the DCI, and the transmission timing of the AP SRS can be determined together with the AP SRS triggering information configured in the higher layer. In this case, in addition to the existing SRS request field for triggering AP SRS, an additional DCI for determining the flexible offset may be required. The BS can notify the UE of the MAC CE including the flexible offset information, and can send the code point and SRS request field for indicating the flexible offset to the UE through DCI at the APSRS triggering time. The UE can select the AP SRS resource set according to the SRS request field indicated by the DCI, and can determine the flexible offset in the MAC CE by referring to the code point of the flexible offset. The UE can determine the transmission timing of the triggered AP SRS by using the flexible offset configured through the MAC CE and the configuration information of the selected AP SRS resource set.

[0568] Fig.31 A MAC CE for indicating a flexible offset of an AP SRS resource set according to an embodiment is shown.

[0569] Reference Fig.31 , the MAC CE used to indicate the flexible offset of the AP SRS resource set can be configured to include the following fields.

[0570] - Cell ID of SRS resource set 31-00: This field indicates the identity of the serving cell including the indicated AP SRS resource set.

[0571] - BWP ID of SRS resource set 31-05: This field indicates the UL BWP including the AP SRS resource set indicated by the codepoint of the DCI bandwidth part indicator field.

[0572] -T i 31-10: This field indicates the activation / deactivation status of the flexible offset. The flexible offset and operation previously defined between the BS and the UE may be as defined in 31-15, and when the UE receives a signal corresponding to T i When a DCI is received, the UE can perform defined operations according to the code point. 0 Instructions to cancel 31-20, T 1 ~T M-1 Indicates new trigger 31-25, T M ~T 2M-2 Instructions to adjust 31-30, while T 2M-1 Indicates AP SRS triggering 31-35 in higher layer configuration.i The activation of the associated flexible offset, T i can be set to 1. To indicate that the i Deactivation of the associated flexible offset, T i Can be set to 0.

[0573] Fig.31 The code point of is only an example, and the number of code points constituting operations 31-20 to 31-35 for dynamic AP SRS triggering may be defined in any of various combinations. When the number of flexible offsets activated by the MAC CE is N, the additional DCI bit for indicating the flexible offset may be set to

[0574] Optionally, in Fig.31 In the present invention, instead of defining a flexible offset and an operation previously defined between a BS and a UE, the flexible offset value and the operation for the offset may be indicated through a MAC CE.

[0575] Fig.32 A MAC CE for indicating a flexible offset value and offset operation is shown.

[0576] refer to Fig.32 , indicating a field T used to indicate activation / deactivation of flexible offset i 32-10 and field T i The MAC CE with the associated flexible offset value 32-15 can be used to determine the transmission timing of the triggered AP SRS. When the BS activates all 2M code points indicated by the MAC CE, the field T i 32-10 may be set to reserved (R), or may be omitted by being included in the Flexible Offset i field (32-15). Fig.32 The code point is merely an example, and the number of code points constituting operations 32-25 to 32-40 for dynamic AP SRS triggering may be defined in any of various combinations. Fig.31 As shown, when the number of activated flexible offsets is N, the additional DCI bit used to indicate the flexible offset can be set to And when both 2M code points are activated and supported, additional DCI bits can be set to

[0577] Example 6-3 :Group-based dynamic AP SRS triggering method using MAC CE

[0578] As the method defined in Embodiment 5, MAC CE can be used when performing AP SRS triggering based on group DCI using DCI format 2_3. In this case, a group-based dynamic AP SRS triggering method using DCI format 2_3 can be defined according to a MAC CE indicating triggering AP SRS.

[0579] As in the method defined in Example 6-1, the UE may receive a MAC CE from the BS and may activate an AP SRS resource set configured in a higher layer. The UE may receive DCI format 2_3 from the BS and may compare the SRS request field included in one or more blocks configured for the UE in the block of DCI format 2_3 with the aperiodicSRS-ResourceTrigger or aperiodicSRS-ResourceTriggerList of the aperiodic SRS resource set activated by the MAC CE to trigger the AP SRS. The activated AP SRS resource set may be triggered, whose aperiodicSRS-ResourceTrigger is set to the same value as the SRS request field of the block of DCI format 2_3 configured for the UE, or includes the same value as the SRS request field in the aperiodicSRS-ResourceTriggerList. In this case, the BS may configure and support the same MAC CE for multiple UEs, or configure and support different MAC CEs for each UE.

[0580] As in the method defined in Embodiment 6-2, when the flexible offset is configured by MAC CE, the value indicating the flexible offset of the block of DCI format 2_3 may be additionally configured. The UE may receive a MAC CE from the BS, and the flexible offset may be activated, or the flexible offset information may be obtained. The UE may receive DCI format 2_3 from the BS, and may compare the SRS request field included in one or more blocks configured for the UE in the block of DCI format 2_3 with aperiodicSRS-ResourceTrigger or aperiodicSRS-ResourceTriggerList to trigger the AP SRS. An AP SRS resource set whose aperiodicSRS-ResourceTrigger is set to the same value as the SRS request field of the block of DCI format 2_3 configured for the UE or includes the same value as the SRS request field in the aperiodicSRS-ResourceTriggerList may be triggered. The flexible offset may be determined based on the value indicating the flexible offset included in the block of DCI format 2_3 and the MAC CE, and the transmission timing of the triggered AP SRS resource set may be determined by using the flexible offset. In this case, the BS may configure and support the same MAC CE for multiple UEs, or configure and support a different MAC CE for each UE.

[0581] Example 6-4 :AP SRS triggering method using AP SRS resource activation based on MAC CE

[0582] In Example 6-1, dynamic AP SRS triggering is performed by indicating activation information of the AP SRS resource set through MAC CE. In Example 6-4, a method for sending activated SRS resources when indicating whether the SRS resources configured in the AP SRS resource set are activated and the AP SRS resource set is triggered through MAC CE will be described. When the SRS resource set and SRS resources are configured in a higher layer, the UE can trigger all SRS resources in the SRS resource set configured according to the SRS request field indicated by the DCI. In Rel-15 / 16, the SRS-ResourceId included in the "srs-ResourceList" in the higher layer parameter SRS resource set determines the SRS resources in the corresponding SRS resource set. Even when only some of all SRS resources in the SRS resource set are needed, all SRS resources in the SRS resource set can be triggered. According to an embodiment of the present disclosure, by indicating the activation status of the SRS resources configured for each AP SRS resource set ID through MAC CE, the SRS resources can be configured to be dynamically triggered when the AP SRS is triggered.

[0583] Fig.33 A MAC CE for indicating activation of SRS resources in an AP SRS resource set according to an embodiment is shown.

[0584] Reference Fig.33 , the MAC CE used to indicate the activation of SRS resources in the AP SRS resource set can be configured to include the following fields.

[0585] - Cell ID of SRS resource set 33-00: This field indicates the identity of the serving cell including the indicated AP SRS resource set.

[0586] - BWP ID of SRS resource set 33-05: This field indicates the UL BWP including the AP SRS resource set indicated by the codepoint of the DCI bandwidth part indicator field.

[0587] -AP SRS ResourceSet ID i 33-10: This field indicates the ID of the AP SRS resource set.

[0588] -T i,l 33-15: This field indicates the AP SRS resource set i (SRS Resource Set i ) in the SRS resource set. When up to L SRS resources can be configured in the AP SRS resource set, T i,l Can be set to 1 to indicate the activation status of the lth SRS resource in AP SRS resource set i. i,l It can be set to 0 to indicate the deactivated state of the 1st SRS resource of AP SRS resource set i.

[0589] Fig.34 FIG. 1 is a flow chart showing an AP SRS triggering process according to an embodiment. Specifically, Fig.34 is a flow chart showing a dynamic AP SRS triggering process based on higher layer parameters, MAC CE indicating the activation state of the AP SRS resource set, and DCI. As in the above embodiments, the UE may perform dynamic AP SRS triggering based on MAC CE and DCI.

[0590] Reference Fig.34 In steps 34-05, 34-10 and 34-15, based on the RRC configuration information of the SRS resource set and the MAC CE information indicating the activation status of the AP SRS resource set, the UE can receive DCI format 0_1, 1_1 or 2_3 for triggering AP SRS.

[0591] In step 34-20, the UE checks the SRS request field for the AP SRS triggering status.

[0592] In step 34-25, the UE determines whether the SRS request field is set to 00 among 00, 01, 10, and 11. When the SRS request field is set to 00, in step 34-35, the UE may determine that the AP SRS resource set is not triggered.

[0593] In step 34-30, the UE may trigger an AP SRS resource set in which aperiodicSRS-ResourceTrigger is set to the same value as the SRS resource field from the activated AP SRS resource set indicated by the MAC CE.

[0594] Fig.35 is a flow chart showing an AP SRS triggering process according to an embodiment. Specifically, Fig.35 is a flow chart showing a dynamic AP SRS triggering process based on higher layer parameters, MAC CE and DCI for configuring flexible offset for AP SRS triggering. As in the above embodiments, the UE may perform dynamic AP SRS triggering based on MAC CE and DCI.

[0595] Reference Fig.35 In steps 35-05, 35-10 and 35-15, based on the RRC configuration information of the SRS resource set and the MAC CE information for configuring the flexible offset of the AP SRS triggering, the UE may receive DCI format 0_1, 1_1 or 2_3 for AP SRS triggering.

[0596] In step 35-20, the UE checks the SRS request field for the AP SRS triggering status.

[0597] In step 35-25, the UE determines whether the SRS request field is set to 00 among 00, 01, 10, and 11. When the SRS request field is set to 00, in step 35-35, the UE determines that the AP SRS resource set is not triggered.

[0598] In step 35-30, the UE selects an AP SRS resource set whose aperiodicSRS-ResourceTrigger is set to the same value as the SRS resource field or includes the same value as the SRS request field in the aperiodicSRS-ResourceTriggerList from the AP SRS resource set. The UE can determine the flexible offset based on the MAC CE, the code point of the flexible offset indicated by the DCI, and the configuration information of the selected AP SRS resource set, and can trigger the AP SRS resource set by using the determined flexible offset.

[0599] Example 7 :How to change the slotOffset value of AP SRS resource set based on MAC CE

[0600] The BS may change the slotOffset value configured in the UE through a higher layer by using a MAC CE. The BS may send a MAC CE to the UE for activating the slotOffset change. The UE may receive the MAC CE, may check the slotOffset value in the MAC CE, and may change the configured slotOffset value to the slotOffset value in the MAC CE. The UE may determine the AP SRS transmission time 3 time slots after the MAC CE reception time by using the slotOffset value in the MAC CE. The MAC CE may include an SRS-ResourceSetId for changing the slotOffset value configured through a higher layer and the slotOffset value to which the configured slotOffset value will be changed.

[0601] Fig.36 is a flow chart illustrating a process by which a BS indicates triggering of an AP SRS and dynamically changes the transmission timing by considering a new slot offset for dynamically determining the timing of the AP SRS based on higher layer parameters and DCI according to an embodiment.

[0602] As in the above-mentioned embodiment, the BS may indicate an SRS request field for AP SRS triggering and a new slot offset for dynamically determining the transmission timing of the AP SRS through DCI to trigger the AP SRS, and may receive the triggered AP SRS from the UE.

[0603] refer to Fig.36 In step 36-05, the BS may receive from the UE a UE capability for reporting whether the transmission timing of the AP SRS may be dynamically changed.

[0604] In step 36-10, the BS determines whether the UE can dynamically change the transmission timing of the AP SRS. When the UE cannot dynamically change the transmission timing of the AP SRS, in steps 36-40 and 36-45, the BS configures higher layer parameters for the SRS resource set in the UE as in Rel-15 / 16 and performs AP SRS triggering as in Rel-15 / 16.

[0605] In steps 36-40, higher layer parameters may include SRS-ResourceSet, and thus, aperiodicSRS-ResourceTrigger (aperiodicSRS-ResourceTriggerList, when present) and slotOffset may be included in the SRS-ResourceSet.

[0606] When the UE is able to dynamically change the transmission timing of the AP SRS, in step 36-15, a higher layer parameter may be configured. Higher layer parameters for SRS resource sets (including a higher layer parameter SRS-ResourceSet) and higher layer parameters for dynamically changing the transmission timing of the AP SRS defined in Rel-15 / 16 are configured. The BS may set a higher layer parameter for dynamically changing the transmission timing of the AP SRS (e.g., "enableDynamicslotOffsetforAPSRS") to "on" or "off", or may not configure a higher layer parameter for dynamically changing the transmission timing of the AP SRS.

[0607] In step 36-20, the BS determines the AP SRS triggering method by determining whether a higher layer parameter (eg, "enableDynamicslotOffsetforAPSRS") is set to "on".

[0608] When the higher layer parameter 'enbleDynamicslotOffsetforAPSRS' is not set to 'on', in steps 36-45, the BS performs AP SRS triggering for the UE as in Rel-15 / 16.

[0609] When the higher layer parameter 'enbleDynamicslotOffsetforAPSRS' is set to 'on', the BS determines whether to perform AP SRS triggering in step 36-25.

[0610] When the BS does not trigger the AP SRS, the BS transmits a DCI including an SRS request field set to 00 to the UE in step 36-50.

[0611] When the BS triggers the AP SRS, in step 36-30, the BS transmits to the UE a DCI including an SRS request field not set to 00. When the BS dynamically determines the transmission timing of the AP SRS, the BS may add a new slot offset for dynamically determining the transmission timing of the AP SRS to the DCI and may transmit the DCI to the UE.

[0612] In steps 36-35, the BS may receive the AP SRS transmitted by the UE at the determined AP SRS transmission timing.

[0613] Fig.37 is a flowchart illustrating a process according to an embodiment, by which the UE determines the transmission timing of the AP SRS to be transmitted by also considering the time slot offset configured by the higher layer parameters and the new time slot offset for dynamically determining the timing of the AP SRS based on the DCI together.

[0614] As in the above embodiment, the UE may dynamically determine the transmission timing of the triggered AP SRS based on the DCI.

[0615] refer to Fig.37 In step 37-05, the UE sends a UE capability to the BS for reporting whether the AP SRS transmission timing can be changed dynamically.

[0616] In step 37-10, the UE receives the RRC configuration of the SRS resource set from the BS. The configured higher-layer parameters may include SRS-ResourceSet and aperiodicSRS-ResourceTrigger (aperiodicSRS-ResourceTriggerList, when present) for performing DCI-based triggering, and slotOffset for transmission timing determination may be included in SRS-ResourceSet. In addition, a higher-layer parameter for supporting dynamic transmission timing change (e.g., "enableDynamicslotOffsetforAPSRS" configuration information) may be received based on whether the APSRS transmission timing can be dynamically changed.

[0617] In step 37-15, when a higher layer parameter received from the BS, such as "enableDynamicslotOffsetforAPSRS", is set to "on", the UE dynamically receives the AP SRS transmission timing. In step 37-25, when a higher layer parameter (e.g., "enableDynamicslotOffsetforAPSRS") is not configured or is set to "off", the UE is expected to perform AP SRS triggering and transmission timing determination in the same manner as in Rel-15 / 16, that is, by determining the transmission timing of the periodic SRS using only the slot offset configured in the higher layer.

[0618] In step 37-20, the UE receives DCI for triggering AP SRS.

[0619] In step 37-30, the UE checks the SRS request field for the AP SRS triggering status.

[0620] In step 37 - 35 , the UE determines whether the SRS request field is set to 00 among 00, 01, 10, and 11.

[0621] In step 37-55, when the SRS request field is set to 00, the UE determines that the AP SRS resource set is not triggered.

[0622] In step 37-40, the UE determines whether a new offset for dynamically determining the transmission timing of the AP SRS is received through DCI. When no new offset is received through DCI, in step 37-45, the UE triggers the AP SRS resource set by using only the slot offset configured in the higher layer parameters.

[0623] In step 37-50, when a new offset is received through DCI, the UE triggers AP SRS by changing the AP SRS transmission timing to the new offset indicated by the DCI. In this case, the slot offset configured in the higher layer parameters may or may not be considered.

[0624] Fig.38 is a flowchart illustrating a procedure according to an embodiment, by which a UE determines a triggered transmission timing of an AP SRS by considering a DCI for dynamically determining the transmission timing of an AP SRS and transmits the AP SRS.

[0625] refer to Fig.38 In step 38-05, the UE sends a UE capability to the BS for reporting whether the AP SRS transmission timing is dynamically changeable. When the AP SRS transmission timing is dynamically changeable, the UE can report to the BS whether the adjustment, reordering, and cancellation described in embodiments 2-2, 2-3, and 2-4 are supported.

[0626] In step 38-10, the UE receives the RRC configuration of the SRS resource set from the BS according to the UE capability for reporting whether the AP SRS transmission timing can be changed dynamically. In order to dynamically change and support the AP SRS transmission timing, a higher layer parameter such as "enableDynamicslotOffsetforAPSRS" can be set to "on".

[0627] In steps 38-15 and 38-20, the UE receives a DCI including an SRS request field, and can determine the AP SRS resource set to be transmitted. The UE can determine the AP SRS transmission timing differently depending on whether the DCI received in step 38-15 includes a new slot offset for dynamically changing the AP SRS transmission timing. When the new slot offset for dynamically changing the AP SRS transmission timing is not included in the DCI received in step 38-15, the transmission timing of the AP SRS is determined according to the higher layer parameter slot offset (slotOffset) of the triggered AP SRS resource set. When the new slot offset for dynamically changing the AP SRS transmission timing is included in the DCI received in step 38-15, the transmission timing of the triggered AP SRS can be determined according to the new slot offset indicated by the DCI. The slot offset configured in the higher layer parameters may or may not be considered.

[0628] In step 38-25, the UE determines whether a DCI including an offset for dynamically changing the transmission timing of the triggered AP SRS is received. The field of the new offset included in the DCI received in step 38-25 may be configured differently according to the operation (adjustment, reordering, or cancellation) indicated by the DCI to determine the transmission timing and RRC information configured in step 38-10. When the UE is RRC configured to support adjustment and cancellation according to the reported UE capability and the BS sends a DCI to cancel the triggered AP SRS, the field of the new offset in the DCI may include a main operation field (1 bit) for indicating cancellation in adjustment and cancellation, a detailed operation field (2 bits) for indicating at least one cancellation operation of the three cancellation operations described in Embodiment 2-4, and an offset field for indicating the time slot to be canceled (5 bits, when cancellation of up to 32 time slots is possible). When the UE is capable of supporting only cancellation in adjustment, reordering, and cancellation, the main operation field may be set to 0 bits.

[0629] In steps 38-30 to 38-40, the UE may select and perform one of adjustment, reordering, and cancellation according to the RRC information configured in step 38-10 and the field of the new offset in the DCI received in operation 38-25.

[0630] In step 38-45, the UE may update the transmission timing of the triggered APSRS based on at least one of steps 38-30 to 38-40.

[0631] Example 8 : Method to send or cancel triggered AP SRS according to time slot configuration

[0632] In Embodiment 8, a method for sending or canceling a triggered AP SRS according to a time slot configuration will be described. The BS may send a DCI for triggering an AP SRS in a time slot capable of DL transmission according to the time slot configuration. According to the time slot configuration and the AP SRS transmission process described in the above embodiments of the present disclosure, the UE may send an AP SRS in a time slot capable of AP SRS transmission. In this case, the transmittable time slot may be defined by the following method:

[0633] 1) From the time slots configured in the higher layer parameter tdd-UL-DL-ConfigurationCommon or tdd-UL-DL-ConfigurationCommon and tdd-UL-DL-ConfigurationDedicated, the time slots configured as UL or the time slots in which some symbols having a length sufficient to transmit the AP SRS are configured as UL can be defined as transmittable time slots. The AP SRS can be transmitted through the time slots configured as UL or the symbols configured as UL in the time slots.

[0634] 2) From the time slots configured in the higher layer parameters tdd-UL-DL-ConfigurationCommon or tdd-UL-DL-ConfigurationCommon and tdd-UL-DL-ConfigurationDedicated, the time slots configured as UL or "flexible" or the time slots in which some symbols having a length sufficient to transmit the AP SRS are configured as UL or "flexible" can be defined as transmittable time slots. The AP SRS can be transmitted through the time slots configured as UL or "flexible" or the symbols configured as UL or "flexible" in the time slots.

[0635] In NR version 15 / 16, when the higher layer parameter SlotFormatIndicator is configured, the UE can change the time slot configuration of (multiple) time slots configured as "flexible" by receiving DCI format 2_0. However, the UE does not expect to receive DCI format 2_0 for changing the symbol set in the time slot to DL, and receive a DCI format for indicating SRS transmission in the symbol set in the time slot. That is, in NR version 15 / 16, when the UE receives a DCI for triggering AP SRS for the symbol of the time slot, the UE does not expect to receive DCI format 2_0 for changing the symbol of the time slot to DL. When the UE supports flexible AP SRS triggering, the BS can use DCI format 2_0 to cancel the pre-triggered AP SRS, so as to perform effective resource management and UE power consumption management by relaxing the restrictions on time slot changes using DCI format 2_0. In more detail, the method of canceling the triggered SRS by changing the time slot configuration can be performed according to the following process.

[0636] The BS may receive from the UE a UE capability for reporting that the AP SRS transmission timing is dynamically changeable. The BS may set a higher layer parameter (e.g., "enableDynamicslotOffsetforAPSRS" configuration information) for supporting dynamic transmission timing changes to "enable" according to the UE capability reported by the UE, and may configure higher layer parameters for SRS transmission in the UE. The BS sends a DCI for triggering the AP SRS to the UE, and the UE determines the transmission timing of the AP SRS based on the received DCI and the APSRS triggering method. After the AP SRS is triggered, when the UE receives DCI format 2_0 through another DL time slot or a "flexible" time slot, the UE determines whether the time slot a corresponding to the transmission timing of the triggered AP SRS is changed to DL. When all triggered AP SRS are transmitted through a time slot configured as UL or a symbol configured as UL in a time slot, the UE may transmit the AP SRS according to the determined timing even though the UE receives DCI format 2_0 and changes the "flexible" time slot to DL. When AP SRS is triggered to be transmitted in a slot configured as “flexible” or a symbol configured as “flexible” in a slot, and the slot configuration of the slot or the symbol in the slot is changed to DL due to DCI format 2_0, the UE may cancel the triggered AP SRS by the following method:

[0637] 1) Cancel all triggered AP SRS to be sent after receiving DCI format 2_0.

[0638] 2) Only the triggered AP SRS that cannot be transmitted due to the slot configuration being changed to DL after receiving DCI format 2_0 is canceled.

[0639] Fig.39 A method of triggering AP SRS and canceling the triggering according to a time slot configuration according to an embodiment is shown.

[0640] refer to Fig.39 In 39-00, the UE may provide a time slot configuration according to higher layer parameters ConfigurationCommon and tdd-UL-DL-ConfigurationDedicated. In 39-05, the UE may receive a DCI including an SRS request for triggering an APSRS from the BS, and in 39-10, may determine a transmission timing of the AP SRS.

[0641] In 39-25, the UE may receive DCI format 2_0 including SFI of a slot configured as "flexible" through a third DL slot. In 39-20, the UE may change the slot configuration according to the received DCI format 2_0.

[0642] In 39-30, the UE may know that the "flexible" slot in the sixth slot is changed to a DL slot, and a conflict occurs between AP SRS transmission and the slot format. Upon receiving DCI format 2_0, the UE may perform a method of canceling AP SRS in 39-40 or 39-50.

[0643] At 39-40, when the UE receives DCI format 2_0, and due to the changed slot format, a conflict occurs between AP SRS transmission and the slot format as in 39-30, all triggered AP SRS transmissions may be canceled.

[0644] Alternatively, at 39-50, the UE may cancel transmission of only the AP SRS with the conflict, and may transmit other triggered AP SRS.

[0645] The above-mentioned embodiments and drawings of the present disclosure are provided to easily describe the present disclosure and help understand the present disclosure, but not to limit the scope of the present disclosure. It is understood by those skilled in the art that various modifications can be made based on the technical spirit of the present disclosure. If necessary, the embodiments of the present disclosure can be used in combination. For example, parts of Embodiment 1 and Embodiment 2 of the present disclosure can be combined with each other.

[0646] One or more embodiments of the present disclosure provide a method of transmitting and receiving a UL reference signal for efficient UL or DL ​​transmission and reception in a mobile communication system.

[0647] In the detailed embodiments of the present disclosure, according to the detailed embodiments of the present disclosure, the components included in the present disclosure have been expressed as singular or plural. However, for ease of description, singular or plural expressions have been appropriately selected for the conditions provided, and the present disclosure is not limited to singular or plural components. A component expressed as plural may be configured as a single component, or a component expressed as singular may be configured as multiple components.

[0648] While the present disclosure has been particularly shown and described with reference to certain embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents.

Claims

1. A method performed by a terminal in a wireless communication system, the method comprising: receiving configuration information associated with a sounding reference signal (SRS) via higher layer signaling; receiving downlink control information (DCI) for triggering the SRS in time slot n; and transmitting the SRS in an available time slot from a reference time slot based on the configuration information and the DCI, and wherein the configuration information includes at least one candidate value for indicating the offset (X) of the reference time slot and the available time slot, and The reference time slot corresponds to time slot n+X.

2. The method of claim 1, wherein the available time slot corresponds to the uth available time slot. 3 . The method according to claim 1 , wherein the DCI includes an offset indicator indicating the available time slot among the at least one candidate value. The method according to claim 3 , wherein the number of bits of the offset indicator is determined based on the number of the at least one candidate value.

5. The method of claim 1, further comprising transmitting UE capabilities associated with the available time slot.

6. A terminal in a wireless communication system, the terminal comprising: Transceiver; and at least one processor coupled to the transceiver and configured to: receiving configuration information associated with a sounding reference signal (SRS) via higher layer signaling, receiving downlink control information (DCI) for triggering the SRS in time slot n, and transmitting the SRS in an available time slot from a reference time slot based on the configuration information and the DCI, and wherein the configuration information includes at least one candidate value for indicating the offset (X) of the reference time slot and the available time slot, and The reference time slot corresponds to time slot n+X. The terminal according to claim 6 , wherein the available time slot corresponds to a u-th available time slot. 8 . The terminal according to claim 6 , wherein the DCI includes an offset indicator indicating the available time slot among the at least one candidate value. 9 . The terminal according to claim 8 , wherein the number of bits of the offset indicator is determined based on the number of the at least one candidate value.

10. The terminal of claim 6, wherein the at least one processor is further configured to transmit UE capabilities associated with the available time slot.

11. A method performed by a base station (BS) in a wireless communication system, the method comprising: Sending configuration information associated with a sounding reference signal (SRS) to a terminal via higher layer signaling; Sending downlink control information (DCI) for triggering the SRS in time slot n; and receiving the SRS in an available time slot from a reference time slot based on the configuration information and the DCI, and wherein the configuration information includes at least one candidate value for indicating an offset (X) of the reference time slot and the available time slot, and The reference time slot corresponds to time slot n+X.

12. A base station (BS) in a wireless communication system, the BS comprising: Transceiver; and at least one processor coupled to the transceiver and configured to: Sending configuration information associated with a sounding reference signal (SRS) to a terminal via higher layer signaling; Sending downlink control information (DCI) for triggering the SRS in time slot n; and receiving the SRS in an available time slot from a reference time slot based on the configuration information and the DCI, and wherein the configuration information includes at least one candidate value for indicating an offset (X) of the reference time slot and the available time slot, and The reference time slot corresponds to time slot n+X.

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