Method and apparatus for transmitting and receiving uplink phase tracking reference signal for network coordinated communication system

Abstract

According to the present disclosure, a method for transmitting a physical uplink shared channel (PUSCH) repeatedly to multiple transmission and reception points (mTRPs) is provided, which is performed by a user equipment (UE). The method includes receiving, from a base station, downlink control information (DCI) including phase tracking reference signal (PTRS)-demodulation reference signal (DMRS) association information; determining, based on the PTRS-DMRS association information, a PTRS port for each of a plurality of sounding reference signal (SRS) resource sets; and transmitting, based on the determined PTRS ports, a PTRS.

Description

Technical Field

[0001] This disclosure relates to a method and apparatus for transmitting and receiving uplink phase tracking reference signals in a network cooperative communication system. Background Technology

[0002] To meet the growing demand for wireless data services following the commercialization of fourth-generation (4G) communication systems, considerable effort has been made to develop pre-fifth-generation (5G) or 5G communication systems. This is one reason why 5G or pre-5G communication systems are referred to as surpassing 4G network communication systems or post-Long Term Evolution (LTE) systems. To achieve high data rates, 5G communication systems are being developed in ultra-high frequency bands (millimeter wave (mmWave)), such as the 60 GHz band. To reduce path loss of radio waves in such ultra-high frequency bands and increase the transmission distance of radio waves in 5G communication systems, various technologies have been discussed and are being researched, such as beamforming, massive MIMO, full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and large antennas. To improve the system network for 5G communication systems, various technologies have been developed, such as evolved small cells, advanced small cells, cloud radio access networks (cloud RAN), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communication, coordinated multipoint (CoMP), and interference cancellation. In addition, other technologies have been developed for 5G communication systems, such as hybrid frequency shift keying (FSK), quadrature amplitude modulation (QAM) (FQAM), and sliding window superposition coding (SWSC) as advanced coding and modulation (ACM) schemes, and filter group multicarrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as advanced access schemes.

[0003] The internet has evolved from a human-based network of connections where humans create and consume information to the Internet of Things (IoT), in which distributed components (such as objects) exchange and process information. Among these, the Internet of Everything (IoE) technology, which combines big data processing technologies connected to cloud servers with IoT-related technologies, is emerging. To realize IoT, various technological components are needed, such as sensing technologies, wired / wireless communication and network infrastructure, service interface technologies, and security technologies. In recent years, technologies including sensor networks for connecting objects, machine-to-machine (M2M) communication, and machine-type communication (MTC) have been studied. In the IoT environment, intelligent internet technology (IT) services can be provided to collect and analyze data from interconnected objects to create new value in human life. With the integration and convergence of existing information technology (IT) technologies and various industries, IoT can be applied to various fields, such as smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, healthcare, smart appliances, and high-quality medical services.

[0004] Various attempts have been made to apply 5G communication systems (or New Radio (NR)) to IoT networks. For example, sensor networks, M2M communication, MTC, and related technologies are being implemented using 5G communication technologies, including beamforming, MIMO, and array antennas. As mentioned above, the application of cloud radio access networks (RAN) as a big data processing technology can be seen as an example of the integration of 5G communication technologies and IoT technologies.

[0005] As mentioned above, due to the development of wireless communication systems, various services can be provided, thus requiring methods for smoothly delivering these services. Summary of the Invention

[0006] Technical solution

[0007] This disclosure provides a method and apparatus for transmitting and receiving uplink phase tracking reference signals in a network cooperative communication system. Attached Figure Description

[0008] To gain a more complete understanding of this disclosure and its advantages, reference is now made to the following description in conjunction with the accompanying drawings, wherein like reference numerals denote like parts:

[0009] Figure 1 A schematic diagram of the basic structure of the time-frequency domain in a wireless communication system according to an embodiment of the present disclosure is shown.

[0010] Figure 2 A schematic diagram of the frame, subframe, and time slot structure in a wireless communication system according to an embodiment of the present disclosure is shown.

[0011] Figure 3 A schematic diagram illustrating an example configuration of the bandwidth portion in a wireless communication system according to an embodiment of the present disclosure is shown;

[0012] Figure 4 A schematic diagram illustrating an example of the configuration of the control resource set (CORESET) of the downlink control channel in a wireless communication system according to an embodiment of the present disclosure is shown.

[0013] Figure 5A A schematic diagram of the structure of a downlink control channel in a wireless communication system according to an embodiment of the present disclosure is shown;

[0014] Figure 5B The illustration shows a schematic diagram of a user equipment (UE) having multiple physical downlink control channel (PDCCH) monitoring locations in a time slot, according to an embodiment of the present disclosure in a wireless communication system, with the span shown.

[0015] Figure 6 A schematic diagram illustrating an example of discontinuous reception (DRX) operation in a wireless communication system according to an embodiment of the present disclosure is shown.

[0016] Figure 7 An example schematic diagram of base station beam allocation configured according to the Transmission Configuration Indication (TCI) state in a wireless communication system according to an embodiment of the present disclosure is shown;

[0017] Figure 8 A schematic diagram illustrating an example of a TCI state allocation method for a PDCCH in a wireless communication system according to an embodiment of the present disclosure is shown.

[0018] Figure 9 A schematic diagram of the TCI indication media access control (MAC) control element (CE) signaling structure for the PDCCH demodulation reference signal (DMRS) in a wireless communication system according to an embodiment of the present disclosure is shown.

[0019] Figure 10 An example schematic diagram of beam configuration of CORESET and search space in a wireless communication system according to an embodiment of the present disclosure is shown;

[0020] Figure 11 A schematic diagram illustrating an example of frequency axis resource allocation in a physical downlink shared channel (PDSCH) in a wireless communication system according to an embodiment of the present disclosure is shown.

[0021] Figure 12 A schematic diagram illustrating an example of time axis resource allocation for a PDSCH in a wireless communication system according to an embodiment of the present disclosure is shown.

[0022] Figure 13AA schematic diagram illustrating an example of time-axis resource allocation based on subcarrier intervals of data channels and control channels in a wireless communication system according to an embodiment of the present disclosure is shown.

[0023] Figure 13B An example of Physical Uplink Shared Channel (PUSCH) retransmission type B in a wireless communication system according to an embodiment of the present disclosure is shown;

[0024] Figure 14 A schematic diagram of the radio protocol architecture of a base station and a UE in a wireless communication system under single-cell, carrier aggregation (CA), and dual connectivity (DC) scenarios according to embodiments of the present disclosure is shown.

[0025] Figure 15 An example schematic diagram of antenna port configuration and resource allocation for cooperative communication in a wireless communication system according to an embodiment of the present disclosure is shown;

[0026] Figure 16 An example schematic diagram of the configuration of downlink control information (DCI) for cooperative communication in a wireless communication system according to an embodiment of the present disclosure is shown;

[0027] Figure 17 A flowchart illustrating the operation of a base station and a UE with respect to repeated PUSCH transmissions according to an embodiment of the present disclosure is shown, considering multiple transmit and receive points (TRPs) based on a single DCI transmission, wherein multiple probe reference signal (SRS) resource indicator (SRI) or transport precoding matrix indicator (TPMI) fields exist.

[0028] Figure 18 A flowchart illustrating the operation of a base station and a UE with respect to repeated PUSCH transmissions according to an embodiment of the present disclosure is shown, considering multiple TRPs based on a single DCI transmission using improved SRI and TPMI fields;

[0029] Figure 19 A schematic diagram is shown to illustrate a method for independently determining frequency hopping and transmission beam mapping during repeated transmissions of PUSCH considering multiple TRPs, according to embodiments of the present disclosure.

[0030] Figure 20 A schematic diagram is shown for describing the configuration of a transmission beam mapping unit based on the configuration of a frequency hopping unit according to an embodiment of the present disclosure;

[0031] Figure 21An example of a method for determining the phase tracking reference signal (PTRS)-DMRS association field considering multiple TRPs is shown by reinterpreting the PTRS-DMRS association field with respect to the case that the maximum number of PTRS ports is 2 and performing layer 2 non-codebook PUSCH repetitions that take into account multiple TRPs.

[0032] Figure 22 An example of a method for determining the PTRS-DMRS association field considering multiple TRPs is shown by reinterpreting the PTRS-DMRS association field with respect to the maximum number of PTRS ports being 2 and performing layer 3 noncodebook PUSCH retransmissions that take into account multiple TRPs.

[0033] Figure 23 An example of a method for determining the PTRS-DMRS association field considering multiple TRPs is shown by reinterpreting the PTRS-DMRS association field with respect to the maximum number of PTRS ports being 2 and performing the case of repeated transmission of the layer 2 codebook PUSCH considering multiple TRPs.

[0034] Figure 24 An example of a method for determining the PTRS-DMRS association field considering multiple TRPs is shown by reinterpreting the PTRS-DMRS association field with respect to the maximum number of PTRS ports being 2 and performing the case of repeated transmission of the layer 3 codebook PUSCH considering multiple TRPs.

[0035] Figure 25 A flowchart illustrating the configuration of the PTRS-DMRS association field considering repeated PUSCH transmissions of multiple TRPs according to embodiments of the present disclosure and the operation of performing PTRS-DMRS association is shown.

[0036] Figure 26 A structural diagram of a UE in a wireless communication system according to an embodiment of the present disclosure is shown; and

[0037] Figure 27 A structural diagram of a base station in a wireless communication system according to an embodiment of the present disclosure is shown. Detailed Implementation

[0038] An apparatus and method for effectively providing services in a mobile communication system are provided.

[0039] According to embodiments of this disclosure, a method is provided performed by a user equipment (UE) for repeatedly transmitting a physical uplink shared channel (PUSCH) to multiple transmission and reception points (mTRPs). The method includes: receiving downlink control information (DCI) from a base station, including phase tracking reference signal (PTRS)-demodulation reference signal (DMRS) association information; determining a PTRS port for each sounding reference signal (SRS) resource set in multiple SRS resource sets based on the PTRS-DMRS association information; and transmitting PTRS based on the determined PTRS port.

[0040] In one embodiment, the phase tracking reference signal (PTRS)-demodulation reference signal (DMRS) association information includes the most significant bit indicating the association between the PTRS port and the DMRS port of the first TRP in the mTRP, and the least significant bit (LSB) indicating the association between the PTRS port and the DMRS port of the second TRP in the mTRP.

[0041] In one embodiment, when the maximum number of PTRS ports is 1, the PTRS-DMRS association information indicates that the maximum number of PTRS ports is associated with the maximum number of DMRS ports is 2.

[0042] In one embodiment, where the maximum number of PTRS ports is 2, the PTRS-DMRS association information indicates that each DMRS port is associated with the same PTRS port.

[0043] In one embodiment, the DCI includes at least one SRS Resource Indicator (SRI), and the method further includes: determining the number of PTRS ports for the SRS resource based on the at least one SRI.

[0044] In one embodiment, the DCI includes at least one Transport Precoding Matrix Indicator (TPMI), and the method further includes determining the number of PTRS ports for SRS resources based on at least one TPMI.

[0045] In one embodiment, the PTRS-DMRS association information includes table information indicating the association between PTRS ports and DMRS ports.

[0046] In one embodiment, the PTRS-DMRS association information includes table information indicating the association between PTRS ports and DMRS ports, and the PTRS ports for each SRS resource set are determined based on the table information and the number of PTRS ports for the SRS resources.

[0047] In one embodiment, the DCI includes additional PTRS-DMRS association information.

[0048] In one embodiment, the method is used for non-codebook-based PUSCH repetition transmission.

[0049] In one embodiment, the method is used for codebook-based PUSCH repetition transmission.

[0050] According to embodiments of this disclosure, a user equipment (UE) is provided for repeatedly transmitting a physical uplink shared channel (PUSCH) to multiple transmit and receive points (mTRP). The UE includes a memory, a transceiver, and at least one processor coupled to the memory and the transceiver. The processor is configured to: receive downlink control information (DCI) from a base station, including phase tracking reference signal (PTRS)-demodulation reference signal (DMRS) association information; determine a PTRS port for each SRS resource set in a plurality of sounding reference signal (SRS) resource sets based on the PTRS-DMRS association information; and transmit PTRS based on the determined PTRS port.

[0051] In one embodiment, the phase tracking reference signal (PTRS)-demodulation reference signal (DMRS) association information includes the most significant bit indicating the association between the PTRS port and the DMRS port of the first TRP in the mTRP, and the least significant bit (LSB) indicating the association between the PTRS port and the DMRS port of the second TRP in the mTRP.

[0052] In one embodiment, the DCI includes at least one SRS Resource Indicator (SRI), and the at least one processor is further configured to determine the number of PTRS ports for the SRS resource based on the at least one SRI.

[0053] In one embodiment, the DCI includes at least one Transport Precoding Matrix Indicator (TPMI), and the at least one processor is further configured to determine the number of PTRS ports for SRS resources based on the at least one TPMI.

[0054] Additional aspects will be set forth in part in the description which follows, and will be apparent in part from the description, or may be learned by practicing the embodiments presented in this disclosure.

[0055] Implementation

[0056] Before proceeding with the detailed description below, it may be advantageous to define certain words and phrases used throughout this patent document: the terms “comprising” and “including” and their derivatives mean unrestricted inclusion; the term “or” is inclusive, meaning and / or; the phrases “associated with” and “associated with” and their derivatives may mean including, being included, interconnected, containing, being contained, connected to or connected with, coupled to or coupled with, communicable with, cooperating, interleaving, juxtaposing, proximate, being combined with or combined with, having, having characteristics, etc.; the term “controller” means any device, system, or part thereof that controls at least one operation, such device may be implemented in hardware, firmware, or software, or at least some combination of both. It should be noted that the functionality associated with any particular controller may be centralized or distributed, local or remote.

[0057] Furthermore, the various functions described below can be implemented or supported by one or more computer programs, each computer program being formed by computer-readable program code and contained in a computer-readable medium. The terms "application" and "program" refer to one or more computer programs, software components, instruction sets, procedures, functions, objects, classes, instances, associated data, or portions thereof suitable for implementation in appropriate computer-readable program code. The phrase "computer-readable program code" includes any type of computer code, including source code, object code, and executable code. The phrase "computer-readable medium" includes any type of medium accessible by a computer, such as read-only memory (ROM), random access memory (RAM), hard disk drive, optical disc (CD), digital video disc (DVD), or any other type of storage. "Non-transitory" computer-readable media does not include wired, wireless, optical, or other communication links that transmit transient electrical or other signals. Non-transitory computer-readable media includes media that can permanently store data and media that can store data and be rewritten later, such as rewritable optical discs or erasable storage devices.

[0058] This patent document provides definitions for certain words and phrases, and those skilled in the art should understand that, in many cases, if not most, such definitions apply to the prior and future use of the words and phrases defined in this way.

[0059] The following discussion Figures 1 to 27 The various embodiments used to describe the principles of this disclosure in this patent document are merely exemplary and should not be construed in any way as limiting the scope of this disclosure. Those skilled in the art will understand that the principles of this disclosure can be implemented in any suitably arranged system or device.

[0060] In the following description, embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0061] In describing embodiments of this disclosure, descriptions of technical content known in the art to which this disclosure pertains and not directly related to this disclosure will be omitted. By omitting unnecessary descriptions, the main points of this disclosure can be conveyed more clearly without obscuring the subject matter.

[0062] For the same reason, components in the accompanying drawings may be exaggerated, omitted, or shown schematically for clarity. Furthermore, the size of each component does not perfectly reflect its actual size. In the drawings, the same reference numerals denote the same elements.

[0063] The advantages and features of this disclosure, as well as the methods of implementing this disclosure, can be more readily understood by referring to the following detailed description and accompanying drawings of embodiments thereof. In this regard, embodiments of this disclosure may take different forms and should not be construed as limited to the description set forth herein. Rather, these embodiments of this disclosure are provided to make this disclosure thorough and complete, and to fully convey the concepts of this disclosure to those skilled in the art, and this disclosure is defined only by the appended claims. Throughout the specification, the same reference numerals denote the same elements. In describing this disclosure, detailed descriptions of related well-known functions or configurations may be omitted where it is thought that they might unnecessarily obscure the essence of this disclosure. Furthermore, the terms used below are defined in consideration of the functions in this disclosure, and these terms may have different meanings depending on the intent, habits, etc., of the user or operator. Therefore, these terms should be defined based on the description throughout the specification.

[0064] Throughout the disclosure, the expression "at least one of a, b, and c" means 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.

[0065] Examples of terminals may include user equipment (UE), mobile station (MS), cellular phone, smartphone, computer, multimedia system capable of performing communication functions, etc.

[0066] In this disclosure, the controller may also be referred to as a processor.

[0067] In this disclosure, a layer (or layer device) may also be referred to as an entity.

[0068] In the following text, a base station is an entity that allocates resources to a terminal and can be at least one of a gNode B (gNB), an eNode B (eNB), a Node B (NB), a base station (BS), a radio access unit, a BS controller, and a node on a network. In this disclosure, a downlink (DL) is a radio transmission path from the base station to the terminal, and an uplink (UL) is a radio transmission path from the terminal to the base station. Furthermore, in the following text, Long Term Evolution (LTE) or Advanced Long Term Evolution (LTE-A) systems may be described as examples, but embodiments of this disclosure can also be applied to other communication systems with similar technical backgrounds or channel configurations. Another example of communication may include fifth-generation mobile communication technology (5G or New Radio (NR)) developed after LTE-A, and in the following text, 5G may have concepts including existing LTE, LTE-A, and another similar service. Moreover, those skilled in the art will understand that this disclosure can be applied to other communication systems with some modifications without departing from the scope of this disclosure.

[0069] Here, it will be understood that the combination of boxes in a flowchart or process flowchart can be executed by computer program instructions. Because these computer program instructions can be loaded into the processor of a general-purpose computer, a special-purpose computer, or another programmable data processing device, the instructions executed by the processor of the computer or other programmable data processing device create units for performing the functions described in the flowchart boxes. The computer program instructions can be stored in computer-usable or computer-readable storage that can instruct the computer or other programmable data processing device to perform functions in a specific manner; therefore, the instructions stored in computer-usable or computer-readable storage can also produce a manufacturing project containing instruction units for performing the functions described in the flowchart boxes. The computer program instructions can also be loaded into a computer or other programmable data processing device; therefore, when a series of operations are performed in the computer or other programmable data processing device, the instructions for operating the computer or other programmable data processing device by generating the computer-executed process can provide operations for performing the functions described in the flowchart boxes.

[0070] Furthermore, each box may represent a module, segment, or portion of code comprising one or more executable instructions for performing a specified logical function. It should also be noted that in some alternative implementations, the functions mentioned in the boxes may not appear in a specific order. For example, depending on the corresponding function, two boxes shown consecutively may actually be executed substantially simultaneously, or these boxes may sometimes be executed in reverse order.

[0071] Here, in some embodiments of this disclosure, the term "unit" refers to a software component or hardware component, such as a field-programmable gate array (FPGA) or application-specific integrated circuit (ASIC), that performs a specific function. However, the term "unit" is not limited to software or hardware. A "unit" may be configured to reside in an addressable memory medium or may be configured to operate one or more processors. Thus, for example, the term "unit" may refer to a component such as a software component, an object-oriented software component, a class component, and a task component, and may include processes, functions, attributes, programs, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, or variables. The functionality provided by components and "units" may be associated with a small number of components and "units," or may be divided into additional components and "units." Furthermore, components and "units" may be implemented as one or more central processing units (CPUs) in a playback device or a secure multimedia card. Additionally, in some embodiments of this disclosure, a "unit" may include at least one processor.

[0072] Wireless communication systems have evolved from early voice-centric services to broadband systems that provide high-speed, high-quality packet data services, such as 3GPP's High Speed ​​Packet Access (HSPA), Long Term Evolution (LTE or Evolved Universal Terrestrial Radio Access (E-UTRA)), LTE-Advanced (LTE-A) and LTE-Pro, 3GPP2's High Speed ​​Packet Data (HRPD) and Ultra Mobile Broadband (UMB), and IEEE 802.16e and other communication standards.

[0073] As a representative example of a broadband wireless communication system, the LTE system employs an Orthogonal Frequency Division Multiplexing (OFDM) scheme in the downlink (DL) and a Single-Carrier Frequency Division Multiple Access (SC-FDMA) scheme in the uplink (UL). UL refers to the radio link through which a terminal (User Equipment (UE) or Mobile Station (MS)) transmits data or control signals to a Base Station (BS) (e.g., eNode B), and DL refers to the radio link through which the BS transmits data or control signals to the terminal. In such a multiple access scheme, the data or control information for each user is classified by typically allocating and managing the data or control information, ensuring that the time-frequency resources used to transmit the data or control information for each user do not overlap, i.e., orthogonality is established.

[0074] As the future communication system following LTE, 5G must be able to freely reflect the diverse needs of users and service providers. Therefore, it needs to support services that simultaneously meet various requirements. Services considered for 5G communication systems include enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), and ultra-reliable low-latency communications (URLLC).

[0075] eMBB aims to provide higher data transmission rates than those supported by LTE, LTE-A, or LTE-Pro systems. For example, in a 5G communication system, from the perspective of a base station, eMBB can provide a peak data rate of 20Gbps in the downlink and 10Gbps in the uplink. Furthermore, 5G communication systems need to provide increased user-perceived data rates to terminals while delivering peak data rates. To meet these requirements, improvements to various transmit / receive technologies may be necessary, including further improvements to multiple-input multiple-output (MIMO) transmission technology. Moreover, while current LTE systems use up to 20MHz of transmission bandwidth in the 2GHz band, 5G communication systems utilize bandwidths wider than 20MHz in the 3 to 6GHz or greater bands to meet the required data rates.

[0076] Meanwhile, mMTC is also considering supporting application services such as the Internet of Things (IoT) within 5G communication systems. To effectively deliver IoT, mMTC requires support for large-scale terminal access within a cell, enhanced terminal coverage, improved battery life, and reduced terminal costs. IoT needs to be able to support a large number of terminals within a cell (e.g., 1,000,000 terminals / km²) as it connects to various sensors and devices to provide communication capabilities. Furthermore, due to the nature of the service, mMTC-enabled terminals are more likely to be located in shadow areas not covered by cell coverage, such as underground within buildings; therefore, terminals may require wider coverage than other services offered by 5G communication systems. mMTC-enabled terminals can be configured as inexpensive devices and require very long battery life, such as 10 to 15 years, as frequent battery replacements are difficult.

[0077] Finally, URLLC is a cellular-based wireless communication system used for specific purposes (mission-critical). For example, services used in remote control of robots or machines, industrial automation, unmanned aerial vehicles, remote healthcare, or emergency alerts could be considered. Therefore, communication provided by URLLC can offer very low latency and very high reliability. For example, URLLC-enabled services can meet air interface latency of less than 0.5 milliseconds while having a packet error rate of 10⁻⁵ or lower. Therefore, for URLLC-enabled services, 5G communication systems may need to provide shorter Transmission Intervals (TTIs) than other services, while ensuring reliable communication links through the allocation of wide resources in the frequency band.

[0078] The three services of a 5G system—eMBB, URLLC, and mMTC—can be multiplexed and transmitted within a single system. In this case, the services can use different transmission and reception methods and parameters to meet their diverse needs. Clearly, the 5G system is not limited by these three services.

[0079] [NR Time and Frequency Resources]

[0080] The frame structure of a 5G system will be described in detail below with reference to the accompanying drawings.

[0081] Figure 1 A diagram illustrating the basic structure of the time-frequency domain according to an embodiment of the present disclosure is shown. This time-frequency domain is a radio resource region in a wireless communication system for transmitting data or control channels.

[0082] exist Figure 1 In the diagram, the horizontal axis represents the time domain, and the vertical axis represents the frequency domain. In both the time and frequency domains, the basic unit of a resource is a resource element (RE) 101, which can be defined by an OFDM symbol 102 on the time axis and a subcarrier 103 on the frequency axis. In the frequency domain, (For example, 12) consecutive REs 101 can be configured into a resource block (RB) 104.

[0083] Figure 2 A schematic diagram of a time slot structure considered in a wireless communication system according to an embodiment of the present disclosure is shown.

[0084] Figure 2 An example of the structure of frame 200, subframe 201, and time slot 202 is shown. A frame 200 can be defined as 10 ms. A subframe 201 can be defined as 1 ms; therefore, a frame 200 can include a total of 10 subframes 201. A time slot 202 or 203 can be defined by 14 OFDM symbols (i.e., the number of symbols per time slot). A subframe 201 may include one or more time slots 202 or 203, and the number of time slots 202 or 203 in each subframe 201 may vary depending on the configuration value μ of the subcarrier spacing. Figure 2 The diagram illustrates cases 204 and 205 where the subcarrier spacing configuration value μ is 0 and 1, respectively. In case 204, when μ = 0, a subframe 201 may include one time slot 202, and in case 205, when μ = 1, a subframe 201 may include two time slots 203. In other words, the number of time slots per subframe... The number of time slots per frame can vary depending on the configured value μ of the subcarrier spacing. It can change. Based on each configured value μ of the subcarrier spacing. and It can be defined as shown in Table 1 below.

[0085] [Table 1]

[0086]

[0087] [Bandwidth Component (BWP)]

[0088] Next, the BWP configuration in the 5G communication system will be described in detail with reference to the attached diagram.

[0089] Figure 3 A schematic diagram illustrating a configuration example of a BWP in a wireless communication system according to an embodiment of the present disclosure is shown.

[0090] Figure 3 An example is shown where UE bandwidth 300 is configured in two BWPs, namely BWP#1 301 and BWP#2 302. The base station can configure one or more BWPs for the UE, and the following information can be configured for each BWP.

[0091] [Table 2]

[0092]

[0093] However, this disclosure is not limited to the examples described above, and various parameters related to the BWP can be configured for the UE in addition to the information configured as described above. This information can be sent from the base station to the UE via higher-layer signaling (e.g., Radio Resource Control (RRC) signaling). At least one of the configured BWPs can be activated. Whether to activate the configured BWP can be sent from the base station to the UE semi-statically via RRC signaling or dynamically via downlink control information (DCI).

[0094] According to some embodiments of this disclosure, an initial BWP for initial access can be configured for the UE before the base station establishes an RRC connection via the Master Information Block (MIB). More specifically, the UE can receive configuration information related to a Control Resource Set (CORESET) and a search space, wherein a Physical Downlink Control Channel (PDCCH) can be transmitted. The PDCCH is designed for the UE to receive system information (e.g., Residual System Information (RMSI) or System Information Block 1 (SIB1)) required for initial access via the MIB during the initial access phase. The CORESET and search space configured via the MIB can be assumed to be identifier (ID) 0, respectively. The base station can notify the UE via the MIB of configuration information regarding a specific CORESET (e.g., a CORESET with ID assumed to be 0), such as frequency allocation information, time allocation information, and parametric information. Furthermore, the base station can notify the UE via the MIB of configuration information related to the monitoring period and timing of a specific CORESET, i.e., configuration information related to a specific search space (e.g., a search space with ID assumed to be 0). The UE can consider the frequency domain of a specific CORESET configured to be obtained from the MIB as the initial BWP for initial access. Here, the initial BWP ID can be considered as 0.

[0095] 5G-supported BWP configurations can be used for a variety of purposes.

[0096] According to some embodiments of this disclosure, when the bandwidth supported by the UE is less than the system bandwidth, the base station can support the BWP by configuring the BWP for the UE. For example, the base station can configure the frequency position of the BWP for the UE (configuration information 1), so that the UE can send or receive data at a specific frequency position within the system bandwidth.

[0097] Furthermore, according to some embodiments of this disclosure, in order to support different digital architectures, the base station can configure multiple BWPs relative to the UE. For example, to support the UE to transmit / receive data using subcarrier spacings of 15 kHz and 30 kHz, two BWPs with subcarrier spacings of 15 kHz and 30 kHz, respectively, can be configured. Frequency division multiplexing can be performed on different BWPs, and when data needs to be transmitted / received in a specific subcarrier spacing, the BWP configured with the corresponding subcarrier spacing can be activated.

[0098] According to some embodiments of this disclosure, in order to reduce the power consumption of the UE, the base station can configure a BWP with a different bandwidth relative to the UE. For example, when the UE supports a very wide bandwidth (e.g., 100MHz) and always transmits / receives data via the corresponding bandwidth, very high power consumption may occur. In particular, monitoring unnecessary downlink control channels in a large bandwidth of 100MHz is very inefficient in terms of power consumption when there is no service. Therefore, in order to reduce the power consumption of the UE, the base station can configure a BWP with a relatively small bandwidth relative to the UE, such as a 20MHz BWP. When there is no service, the UE can perform monitoring operations in a 20MHz BWP, and when data is generated, the UE can transmit / receive data via a 100MHz BWP according to the instructions of the base station.

[0099] Regarding the method of configuring the BWP, the UE can receive configuration information about the initial BWP through the Master Information Block (MIB) during the initial access phase before RRC connection. More specifically, the UE can be configured with a CORESET from the MIB via the Physical Broadcast Channel (PBCH). Here, the CORESET is used for the downlink control channel, through which the DCI for scheduling SIBs can be transmitted. The bandwidth of the CORESET configured by the MIB can be considered as the initial BWP, and the UE can receive the Physical Downlink Shared Channel (PDSCH) through which the SIBs are transmitted via the configured initial BWP. In addition to receiving SIBs, the initial BWP can be used for other System Information (OSI), paging, and random access.

[0100] [SS / PBCH block]

[0101] Next, the synchronization signal (SS) / PBCH block in 5G will be described.

[0102] An SS / PBCH block can represent a physical layer channel block that includes a primary SS (PSS), secondary SS (SSS), and PBCH.

[0103] Specifically, the SS / PBCH blocks are as follows:

[0104] PSS: PSS is a signal that serves as a downlink time / frequency synchronization standard and provides partial information about the cell ID.

[0105] SSS: SSS is a standard signal for downlink time / frequency synchronization and provides residual cell ID information not provided by PSS. Furthermore, SSS can be used as a reference signal for PBCH demodulation.

[0106] PBCH: The PBCH provides the basic system information required for the transmission / reception of the UE's data and control channels. This basic system information may include search space-related control information indicating radio resource mapping information for the control channels, and scheduling control information for individual data channels through which system information is transmitted; and

[0107] SS / PBCH Blocks: An SS / PBCH block is composed of PSS, SSS, and PBCH. One or more SS / PBCH blocks can be sent within 5ms, and each sent SS / PBCH block can be identified by an index.

[0108] The UE can detect the PSS and SSS during the initial access phase and can decode the PBCH. The UE can obtain the MIB from the PBCH and can obtain CORESET#0 configured from the MIB (which may correspond to a CORESET with CORESET index 0). The UE can monitor CORESET#0 assuming the SS / PBCH block selected by the UE and the demodulation reference signal (DMRS) transmitted in CORESET#0 are in quasi-co-located (QCL). The UE can receive system information via downlink control information transmitted in CORESET#0. The UE can obtain configuration information related to the random access channel (RACH) required for initial access from the received system information. Considering the selected SS / PBCH index, the UE can transmit a physical RACH (PRACH) to the base station, and the base station receiving the PRACH can obtain information about the index of the SS / PBCH block selected by the UE. Therefore, the base station can identify which SS / PBCH block the UE has selected and which CORESET#0 the UE is monitoring associated with that block.

[0109] [PDCCH: About DCI]

[0110] Next, we will describe DCI in a 5G system in detail.

[0111] In 5G systems, scheduling information for uplink data (or Physical Uplink Shared Channel (PUSCH)) or downlink data (or PDSCH) is transmitted from the base station to the UE via DCI. The UE can monitor the fallback DCI format and the non-fallback DCI format of the PUSCH or PDSCH. The fallback DCI format may include predefined fixed fields between the base station and the UE, while the non-fallback DCI format may include configurable fields.

[0112] Following channel coding and modulation, the DCI (Digital Cipher Interface) can be transmitted via the PDCCH. Cyclic Redundancy Check (CRC) is appended to the DCI message payload, and the CRC can be scrambled with a Radio Network Temporary Identifier (RNTI) corresponding to the UE's identifier. Different RNTIs can be used depending on the purpose of the DCI message, such as UE-specific data transmission, power control commands, or random access responses. In other words, the RNTI is not explicitly transmitted but is sent by including it in the CRC calculation process. When a DCI message is received on the PDCCH, the UE can identify the CRC using the assigned RNTI, and if the CRC identification result is correct, the UE can determine that the corresponding message was sent to the UE.

[0113] For example, the DCI used for scheduling System Information (SI) PDSCH can be scrambled with SI-RNTI. The DCI used for scheduling Random Access Response (RAR) messages can be scrambled with RA-RNTI. The DCI used for scheduling paging messages can be scrambled with P-RNTI. The DCI notifying Slot Format Indicator (SFI) can be scrambled with SFI-RNTI. The DCI notifying Transmit Power Control (TPC) can be scrambled with TPC-RNTI. The DCI used for scheduling UE-specific PDSCH or PUSCH can be scrambled with Cell RNTI (C-RNTI).

[0114] DCI format 0_0 can be used as a fallback DCI for scheduling PUSCH, and in this case, CRC can be scrambled with C-RNTI. DCI format 0_0 with CRC scrambled with C-RNTI can include the following information.

[0115] [Table 3]

[0116]

[0117] DCI format 0_1 ​​can be used as a non-back-off DCI for scheduling PUSCH, and in this case, CRC can be scrambled with C-RNTI. DCI format 0_1 ​​with CRC scrambled with C-RNTI can include the following information.

[0118] [Table 4]

[0119]

[0120]

[0121] DCI format 1_0 can be used as a fallback DCI for scheduling PDSCH, in which case CRC can be scrambled with C-RNTI. DCI format 1_0 with CRC scrambled with C-RNTI can include the following information.

[0122] [Table 5]

[0123]

[0124]

[0125] DCI format 1_1 can be used as a non-back-off DCI for scheduling PDSCH, and in this case, CRC can be scrambled with C-RNTI. DCI format 1_1 with CRC scrambled with C-RNTI can include the following information.

[0126] [Table 6]

[0127]

[0128]

[0129] [PDCCH: CORESET, REG, CCE, search space]

[0130] The downlink control channel in a 5G communication system will be described in detail below with reference to the accompanying drawings.

[0131] Figure 4 An example schematic diagram is shown of transmitting a CORESET downlink control channel in a wireless communication system according to an embodiment of the present disclosure. Figure 4 An example is shown where the UE BWP 410 is configured on the frequency axis, and two CORESETs (CORESET#1 401 and CORESET#2 402) are configured in a time slot 420 on the time axis. CORESET#1 and #2 401 and 402 can be configured on a specific frequency resource 403 within the entire UE BWP 410 on the frequency axis. One or more OFDM symbols can be configured on the time axis and can be defined as CORESET durations 404. (Reference) Figure 4 In the example shown, CORESET#1 401 is configured to have a CORESET duration with two signs, and CORESET#2 402 is configured to have a CORESET duration with one sign.

[0132] In the aforementioned 5G, the base station can configure the CORESET for the UE via higher-layer signaling (e.g., system information, MIB, or RRC signaling). The CORESET configuration for the UE provides information such as the CORESET identifier, the frequency location of the CORESET, and the symbol length of the CORESET. For example, this information may include the following.

[0133] [Table 7]

[0134]

[0135] In Table 7, the tci-StatesPDCCH (hereinafter referred to as Transmission Configuration Indicator (TCI) state) configuration information may include information about one or more SS / PBCH blocks that have a QCL relationship with the DMRS transmitted on the corresponding CORESET, or information about the Channel State Information Reference Signal (CSI-RS).

[0136] Figure 5A An example schematic diagram of a basic unit for configuring the time and frequency resources of a downlink control channel is shown, which can be used in a wireless communication system according to embodiments of this disclosure. Figure 5A The basic unit for configuring the time and frequency resources of the control channel can be called a resource element group (REG) 503, and REG 503 can be defined as an OFDM symbol 501 on the time axis and a physical resource block (PRB) 502 on the frequency axis, that is, it can be defined as 12 subcarriers. The base station connects and attaches REG 503 to each other to configure the downlink control channel allocation unit.

[0137] like Figure 5A As shown, when the basic unit used for allocating downlink control channels in 5G is a Control Channel Element (CCE) 504, one CCE 504 can be configured by multiple REG 503s. For example, Figure 5A The REG 503 shown can be configured with 12 REs, and a CCE 504 can be configured with 72 REs when it is configured with 6 REG 503s. When configuring a downlink CORESET, the downlink CORESET can be configured with multiple CCE 504s, and a specific downlink control channel can be transmitted after being mapped to one or more CCE 504s, depending on the aggregation level (AL) in the CORESET. The CCE 504s in the CORESET are distinguished by numbers, which can be assigned according to a logical mapping scheme.

[0138] Figure 5A The basic unit of the downlink control channel shown (i.e., REG 503) may include the RE mapped to by the DCI and the region mapped to by the DMRS 505 as a reference signal for decoding the RE. Figure 5AAs shown, three DMRS 505s can be transmitted within a single REG 503. Depending on the AL, the number of CCEs required to transmit the PDCCH can be 1, 2, 4, 8, or 16, and different numbers of CCEs can be used to implement link adaptation of the downlink control channel. For example, when AL = L, a downlink control channel can be transmitted via L CCEs. When information about the downlink control channel is unknown, the UE needs to detect the signal, thus requiring a search space to define the set of CCEs indicating blind decoding. The search space is the set of downlink control channel candidates, including the CCEs the UE attempts to decode on a given AL. Here, the UE can have multiple search spaces because there are several ALs that form a group using 1, 2, 4, 8, or 16 CCEs. The search space set can be defined as the set of search spaces in all configured ALs.

[0139] The search space can be categorized into a common search space and a UE-specific search space. A specific group of UEs or all UEs can query the common search space of the PDCCH to receive dynamic scheduling of cell common control information, such as paging messages or system information. For example, PDSCH scheduling allocation information for transmitting SIBs including cell operator information can be received by querying the common search space of the PDCCH. The common search space can be defined as a predetermined set of CCEs, as the UE or group of all UEs needs to receive the PDCCH. UE-specific PDSCH or PUSCH scheduling allocation information can be received by querying the UE-specific search space of the PDCCH. The UE-specific search space can be UE-specific and defined by the UE's identifier and various system parameters.

[0140] In 5G, the parameters of the PDCCH search space can be configured by the base station to the UE via higher-layer signaling (e.g., SIB, MIB, or RRC signaling). For example, the base station can configure for the UE the number of PDCCH candidates in each cell, the monitoring period of the search space, the monitoring timing of symbol cells within the time slots of the search space, the search space type (common search space or UE-specific search space), the combination of DCI formats and RNTIs to be monitored in the search space, and the index of the CORESET used for monitoring the search space. For example, the following information may be included.

[0141] [Table 8]

[0142]

[0143] The base station can configure one or more search space sets for the UE based on configuration information. According to some embodiments of this disclosure, the base station can configure search space set 1 and search space set 2 for the UE. Search space set 1 can be configured to monitor DCI format A scrambled with X-RNTI in a common search space, and search space set 2 can be configured to monitor DCI format B scrambled with Y-RNTI in a UE-specific search space.

[0144] Depending on the configuration information, there can be one or more search space sets in the public search space or the UE-specific search space. For example, search space set #1 and search space set #2 can be configured as the public search space, and search space set #3 and search space set #4 can be configured as the UE-specific search space.

[0145] In the public search space, combinations of DCI formats and RNTI can be monitored. However, this combination is not limited to the following examples:

[0146] The DCI format 0_0 / 1_0 has CRC scrambled by C-RNTI, CS-RNTI, SP-CSI-RNTI, RA-RNTI, TC-RNTI, P-RNTI, and SI-RNTI.

[0147] DCI format 2_0 with CRC scrambled by SFI-RNTI;

[0148] DCI format 2_1 with CRC scrambled by INT-RNTI;

[0149] DCI format 2_2 with CRC scrambled by TPC-PUSCH-RNTI and TPC-PUCCH-RNTI; and

[0150] It has a DCI format 2_3 scrambled by TPC-SRS-RNTI.

[0151] Within the UE-specific search space, combinations of DCI formats and the following RNTIs can be monitored. However, this combination is not limited to the following examples:

[0152] The DCI format is 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, and TC-RNTI; and

[0153] It has a DCI format 1_0 / 1_1 scrambled by C-RNTI, CS-RNTI, and TC-RNTI.

[0154] The specified RNTI can follow the following definitions and usage:

[0155] Cell RNTI (C-RNTI): Used for scheduling UE-specific PDSCH;

[0156] Temporary Cell RNTI (TC-RNTI): Used for scheduling UE-specific PDSCH;

[0157] Configured Scheduling RNTI (CS-RNTI): Used to schedule UE-specific PDSCHs with quasi-static configurations;

[0158] Random Access RNTI (RA-RNTI): Used to schedule PDSCH during random access;

[0159] Paging RNTI (P-RNTI): Used to schedule the PDSCH for sending paging requests;

[0160] System Information RNTI (SI-RNTI): Used to schedule the transmission of system information via PDSCH;

[0161] Interrupt RNTI (INT-RNTI): Used to notify PDSCH of puncturing;

[0162] Transmit power control of PUSCH RNTI (TPC-PUSCH-RNTI): Used to indicate power control commands for PUSCH;

[0163] Transmit power control for PUCCH RNTI (TPC-PUCCH-RNTI): Used to indicate power control commands for the PUCCH; and

[0164] SRS RNTI Transmit Power Control (TPC-SRS-RNTI): A command used to instruct the SRS to control power.

[0165] The DCI format specified above can follow the definition below.

[0166] [Table 9]

[0167]

[0168] In 5G, the search space in all Ls of CORESET p and search space set s can be represented by the following equation 1.

[0169] [Equation 1]

[0170]

[0171] L:AL

[0172] nCI: Carrier Index

[0173] N CCE，p The total number of CCEs existing in CORESET p

[0174] Time slot index

[0175] M (L) p，s，max-1 : Number of PDCCH candidates in ALL

[0176] m snCI =0, ...,M (L) p，s，max-1 : Index of PDCCH candidates in AL L

[0177] i = 0, ..., L-1

[0178] _ Y p，-1 =n RNTI ≠0 A0=39827, A1=39829, A2=39839, D=65537

[0179] nRNTI: UE identifier

[0180] In the public search space, Yp, The value can correspond to 0.

[0181] In the UE-specific search space, Yp, The value can correspond to a value that changes based on the UE's identifier (C- or ID configured for the UE by the base station) and time index.

[0182] In 5G, multiple search space sets can be configured with different parameters (e.g., the parameters in Table 8), so the set of search space sets monitored by the UE can change at each point in time. For example, when search space set #1 is configured with a time slot period of X and search space set #2 is configured with a time slot period of Y, and X is different from Y, the UE can monitor search space set #1 and search space set #2 in a specific time slot, or it can monitor only one of search space set #1 and search space set #2 in a specific time slot.

[0183] [PDCCH: Span]

[0184] For each subcarrier interval, the UE can perform a UE capability report regarding situations where the UE has multiple PDCCH monitoring locations within a time slot, and the concept of a span can be used in this case. A span represents the consecutive symbols of the PDCCH that the UE monitors within a time slot, with each PDCCH monitoring location within a span. A span can be represented as (X, Y), where X represents the minimum number of symbols between the first symbols of two consecutive spans, and Y represents the number of consecutive symbols used to monitor the PDCCH within a span. Here, the UE can monitor the PDCCH within the span portion from the first symbol to symbol Y.

[0185] Figure 5B The diagram illustrates a scenario in a wireless communication system where a UE can have multiple PDCCH monitoring locations within a time slot. Regarding the span, (X, Y) = (7, 4), (4, 3), and (2, 2), and these three cases are respectively... Figure 5B Cases 5B-00, 5B-05, and 5B-10 are represented in the table. For example, case 5B-00 shows a situation where two spans, which can be represented by (7, 4), exist in a time slot. The interval between the first symbols of the two spans is represented by X = 7, the PDCCH monitoring position can appear within a total of Y = 3 symbols starting from the first symbol of each span, and search spaces 1 and 2 each appear within Y = 3 symbols. As another example, case 5B-05 shows a situation where a total of three spans, which can be represented by (4, 3), exist in a time slot, where the interval between the second and third spans is X' = 5 symbols, which is greater than X = 4 symbols.

[0186] [DRX]

[0187] Figure 6 An example schematic diagram of discontinuous reception (DRX) operation in a wireless communication system according to an embodiment of the present disclosure is shown.

[0188] DRX is an operation in which a UE using the service receives data discontinuously in RRC connected state, where a radio link is configured between the base station and the UE. When DRX is applied, the UE can turn on its receiver at specific times to monitor the control channel, and can turn off its receiver to reduce power consumption when no data is received for a specific period of time. The Media Access Control (MAC) entity can control DRX operation based on various parameters and timers.

[0189] refer to Figure 6 Activity time 605 is the time during which the UE wakes up during the DRX period and monitors the PDCCH. Activity time 605 can be defined as follows:

[0190] The following timers are running: drx-onDurationTimer, drx-InactivityTimer, drx-RetransmissionTimerDL, drx-RetransmissionTimerUL, or ra-ContentionResolutionTimer.

[0191] The scheduling request was sent on the PUCCH and is pending; or

[0192] After successfully receiving a random access response for a random access preamble not selected by the MAC entity in a contention-based random access preamble, no PDCCH indicating a new transmission addressing to the MAC entity was received.

[0193] Here, drx-onDurationTimer, drx-InactivityTimer, drx-RetransmissionTimerDL, drx-RetransmissionTimerUL, and ra-ContentionResolutionTimer are timers with values ​​configured by the base station and have the function of configuring the UE to monitor the PDCCH when certain conditions are met.

[0194] `drx-onDurationTimer 615` is a parameter used to configure the minimum wake-up time for the UE during a DRX cycle. `drx-InactivityTimer 620` is a parameter used to configure the additional wake-up time for the UE in case 630 when a PDCCH indicating a new uplink or downlink transmission is received. `drx-RetransmissionTimerDL` is a parameter used to configure the maximum wake-up time for the UE to receive downlink retransmissions during a downlink Hybrid Automatic Request (HARQ) process. `drx-RetransmissionTimerUL` is a parameter used to configure the maximum time during which the UE wakes up to receive permission for uplink retransmissions during an uplink HARQ process. `drx-onDurationTimer 615`, `drx-InactivityTimer 620`, `drx-RetransmissionTimerDL`, and `drx-RetransmissionTimerUL` can be configured by, for example, time, the number of subframes, or the number of time slots. ra-ContentionResolutionTimer is a parameter used to monitor the PDCCH during random access.

[0195] The inactivity time 610 is the time during which the UE does not monitor and / or receive the PDCCH during DRX operation, and can be the remaining time after deducting the activity time 605 from the total time of DRX operation. When the UE does not monitor the PDCCH during the activity time 605, the UE can enter a sleep or inactivity state to reduce power consumption.

[0196] A DRX cycle represents the period during which a UE wakes up and monitors the PDCCH. In other words, a DRX cycle represents the time interval, or duration, between a UE monitoring the PDCCH and monitoring the next PDCCH. There are two types of DRX cycles: short DRX cycles and long DRX cycles. Short DRX cycles can be optionally applied.

[0197] Long DRX cycle 625 is the longest of the two types of DRX cycles configured for the UE. When the UE operates in a long DRX cycle, the UE restarts drx-onDurationTimer 615 at a time point after long DRX cycle 625 from the start point (e.g., the start symbol) of drx-onDurationTimer 615. When the UE operates in long DRX cycle 625, the UE can start drx-onDurationTimer 615 in a time slot after drx-SlotOffset (drx-slot offset) in a subframe that satisfies the following Equation 2. drx-SlotOffset represents the delay before drx-onDurationTimer 615 is started. drx-SlotOffset can be configured by, for example, time or the number of time slots.

[0198] [Equation 2]

[0199] [(SFNΥ10)+subframe number]modulo(drx-LongCycle)=drx-LongCycleStartOffset

[0200] Here, `drx-StartOffset` can be used to define the subframe at the start of a DRX cycle. For example, `drx-LongCycleStartOffset` can be used to define the subframe at the start of a long DRX cycle of 625. `drx-LongCycleStartOffset` can be configured by time, the number of subframes, or the number of time slots.

[0201] [PDCCH: UE Capability Report]

[0202] The slot locations of the aforementioned public search space or UE-specific search space are indicated by the monitoringSymbolsWithinSlot parameter in Table 10-1, and the symbol positions within the slots are indicated by the bitmap using the monitoringSymbolsWithinSlot parameter in Table 9. The following examples of UE capabilities can be used to report to the base station the symbol positions within the slots where the UE can perform search space monitoring.

[0203] In one example of UE capability 1 (hereinafter referred to as FG 3-1), as shown in Table 10-1 below, the current UE capability represents the ability to monitor an MO when the corresponding MO is within the first 3 symbols of the time slot, provided that a monitoring opportunity (MO) exists in the common search space for Type 1 and Type 3 or the UE-specific search space. The current UE capability is a mandatory capability supported by all UEs that support NR. Support for UE capabilities is not explicitly reported to the base station.

[0204] [Table 10-1]

[0205]

[0206]

[0207] In one example of UE capability 2 (hereinafter, FG 3-2), as shown in Table 10-2 below, when an MO (Multiple Object) exists in a time slot for either the common search space or the UE-specific search space, the current UE capability represents the ability to monitor the MO regardless of the position of the start symbol of the corresponding MO. The current UE capability may optionally be supported by the UE. Support for the UE capability is explicitly reported to the base station.

[0208] [Table 10-2]

[0209]

[0210]

[0211] In one example of UE capability 3 (hereinafter, FG 3-5, 3-5a, and 3-5b), as shown in Table 10-3 below, when multiple MOs exist in a time slot for a common search space or a UE-specific search space, the current UE capability indicates the pattern of MOs that can be monitored by the UE. This pattern includes the interval X between the start symbols of the different MOs and the maximum symbol length Y of a MO. The UE-supported combination of (X, Y) can be one or more of {(2, 2), (4, 3), (7, 3)}. The current UE capability can optionally be supported by the UE, and the support of the UE capability and the combination of (X, Y) are explicitly reported to the base station.

[0212] [Table 10-3]

[0213]

[0214]

[0215] The UE can report its support for UE capability 2 and / or UE capability 3, along with related parameters, to the base station. Based on the reported UE capabilities, the base station can perform time-axis resource allocation for both the common search space and the UE-specific search space. During resource allocation, the base station may not position the MO in a location that the UE cannot monitor.

[0216] [PDCCH: BD / CCE Restriction]

[0217] When multiple search space sets are configured for a UE, the following conditions can be considered regarding the method for determining which search space set the UE needs to monitor.

[0218] When the value of monitoringCapabilityConfig-r16, used as higher-layer signaling, is configured for the UE as r15 monitoringcapability, the UE defines the maximum number of PDCCH candidates that can be monitored for each time slot and the maximum number of CCEs in the entire search space (here, the entire search space represents the entire set of CCEs corresponding to the joint area of ​​multiple search space sets). When the value of monitoringCapabilityConfig-r16 is configured for the UE as r16 monitoringcapability, the UE defines the maximum number of PDCCH candidates that can be monitored for each span and the maximum number of CCEs in the entire search space (here, the entire search space represents the entire set of CCEs corresponding to the joint area of ​​multiple search space sets).

[0219] [Table 10-4]. Condition 1: Limit the maximum number of PDCCH candidates.

[0220]

[0221]

[0222] According to the configuration value of the higher-level signaling, when it is configured to have 15.2 μ When defined by time slots in a cell with a subcarrier spacing of kHz, the maximum number M PDCCH candidates that a UE can monitor is... μ Table 11-1 can be followed, and when defined based on span, Table 11-2 should be followed.

[0223] [Table 11-1]

[0224] μ <![CDATA[Maximum number (M μ )]]> 0 44 1 36 2 22 3 20

[0225] [Table 11-2]

[0226]

[0227] [Condition 2: Limit the maximum number of CCEs]

[0228] According to the configuration value of the higher-level signaling, when it is configured to have 15.2 μ When the time slots in a cell with a subcarrier spacing of kHz are defined, the maximum number of CCEs C that can be configured in the entire search space (here, the entire search space represents the set of all CCEs corresponding to the joint region of multiple search space sets) is C. μ You can follow Table 11-3 below, and when defining based on span, follow Table 11-4.

[0229] [Table 11-3]

[0230] μ <![CDATA[Maximum number of non-overlapping CCEs per time slot and per serving cell (C μ )]]> 0 56 1 56 2 48 3 32

[0231] [Table 11-4]

[0232]

[0233] For ease of description, condition A is defined as the condition where both conditions 1 and 2 are satisfied at a specific point in time. Therefore, not satisfying condition A may mean that at least one of conditions 1 and 2 is not satisfied.

[0234] Depending on the search space configuration set by the base station, condition A may not be met at a specific time point. When condition A is not met at a specific time point, the UE can select and monitor only some search space sets configured to meet condition A at that time point, and the base station can send PDCCH through the selected search space sets.

[0235] [PDCCH: Overbooking]

[0236] The method for selecting some search spaces from the set of all configured search spaces can be followed as follows.

[0237] [Method 1]

[0238] If condition A related to PDCCH is not met at a specific time point (time slot), the UE (or base station) may prioritize the search space set configured with a search space type having a UE-specific search space from the search space set existing at that time point, and select the search space set configured with a common search space type.

[0239] When all search space sets configured as the common search space are selected (i.e., even after all search spaces configured as the common search space have been selected, and condition A is still met), the UE (or base station) can select a search space set configured as a UE-specific search space. Here, when multiple search space sets are configured as UE-specific search spaces, the smaller the index of the search space set, the higher its priority. Considering the priority, a UE-specific search space set can be selected within the range where condition A is satisfied.

[0240] [QCL, TCI status]

[0241] In wireless communication systems, one or more different antenna ports (which may be replaced by one or more channels, signals, or combinations thereof, but for ease of description, they are uniformly referred to as different antenna ports) can be associated with each other through the QCL configuration shown in Table 12 below. The TCI state is used to inform the PDCCH (or PDCCH DMRS) of the QCL relationship between another RS ​​or channel. When a reference antenna port A (reference RS#A) and another target antenna port B (target RS#B) are in QCL, the UE is allowed to apply all or some of the large-scale channel parameters estimated in antenna port A to perform channel measurements in antenna port B. QCL may need to be associated based on different parameters 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 12 below.

[0242] [Table 12]

[0243] QCL type Large-scale characteristics A Doppler frequency shift, Doppler spread, average delay, delay spread B Doppler frequency shift, Doppler spread C Doppler shift, average delay D Spatial Rx parameters

[0244] Spatial RX parameters can be general terms for some or all of a variety of 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.

[0245] As shown in Table 13 below, QCL relationships can be configured for a UE using RRC parameters TCI status and QCL information. Referring to Table 13, a base station can configure a UE with at least one TCI status to notify the UE of up to two QCL relationships (qcl-type 1 and qcl-type 2) with respect to the ID of the RS (i.e., the target RS) of the reference TCI status. Each QCL information included in the TCI status (QCL information) can include the corresponding QCL information, the type and ID of the reference RS, and the serving cell index and BWP index of the reference RS indicated by the QCL type, as shown in Table 12 above.

[0246] [Table 13]

[0247]

[0248] Figure 7 An example schematic diagram of base station beam allocation configured according to TCI state in a wireless communication system according to an embodiment of the present disclosure is shown.

[0249] Reference Figure 7 The base station can send multiple pieces of information about N different beams to the UE through N different TCI states. For example, such as Figure 7 As shown, when N is 3, the base station can allow the qcl-type 2 parameter included in each of the three TCI states 700, 705 and 710 to be associated with the CSI-RS or SSB corresponding to different beams, and is configured as QCL type D to notify that the antenna ports involved in different TCI states 700, 705 and 710 are associated with different spatial Rx parameters (i.e., different beams).

[0250] Tables 14-1 to 14-5 indicate the valid TCI status configuration based on the target antenna port type.

[0251] Table 14-1 indicates the valid TCI state configuration when the target antenna port is a CSI-RS (TRS) for tracking. TRS stands for Non-Zero Power (NZP) CSI-RS, where no repetition parameter is configured and trs-Info is configured to true. Configuration 3 in Table 14-1 can be used for non-periodic TRS.

[0252] [Table 14-1] Effective TCI state configuration when the target antenna port is TRS.

[0253]

[0254] Table 14-2 indicates the valid TCI state configuration when the target antenna port is a CSI-RS of CSI. A CSI-RS of CSI refers to an NZP CSI-RS in CSI-RS where no parameters indicating repetition are configured (e.g., repeat parameters) and trs-Info is not configured to true.

[0255] [Table 14-2] Effective TCI State Configuration when the Target Antenna Port is CSI-RS

[0256]

[0257] Table 14-3 indicates the valid TCI state configuration when the target antenna port is the BM's CSI-RS (the same as the CSI-RS reported by L1 RSRP). The BM's CSI-RS refers to the NZP CSI-RS in the CSI-RS, where the repeat parameter is configured to have an on or off value, and trs-Info is not configured to true.

[0258] [Table 14-3] Valid TCI state configuration when the target antenna port is BM's CSI-RS (for L1 RSRP reporting).

[0259]

[0260]

[0261] Table 14-4 shows the valid TCI state configuration when the target antenna port is PDCCH DMRS.

[0262] [Table 14-4] Effective TCI State Configuration when the Target Antenna Port is PDCCH DMRS

[0263]

[0264] Table 14-5 indicates the valid TCI state configuration when the target antenna port is PDSCH DMRS. [Table 14-5] Valid TCI state configuration when the target antenna port is PDSCH DMRS

[0265]

[0266] Representative QCL configuration methods in Tables 14-1 to 14-5 include managing the target antenna port and reference antenna port for each stage by configuring “SSB” -> “TRS” -> “CSI-RS of CSI, CSI-RS of BM, PDCCH DMRS, or PDSCH DMRS”. Therefore, UE reception operations can be aided by associating statistical characteristics measurable from the SSB and TRS with each antenna port.

[0267] [PDCCH: Regarding TCI Status]

[0268] Specifically, the TCI state combinations applicable to the PDCCH DMRS antenna port are shown in Table 14-6 below. The fourth row in Table 14-6 represents the combinations assumed by the UE before RRC configuration, and configurations after RRC are not possible.

[0269] [Table 14-6]

[0270]

[0271] In NR, dynamic allocation of PDCCH beams is supported, such as... Figure 8 The layered signaling method shown.

[0272] Figure 8 A schematic diagram illustrating an example of a TCI state allocation method for a PDCCH in a wireless communication system according to an embodiment of the present disclosure is shown.

[0273] Reference Figure 8 The base station can configure N TCI states 805 to 820 to the UE via RRC signaling 800, and can configure some TCI states as CORESET TCI state 825. Then, the base station can indicate one of CORESET TCI states 830 to 840 to the UE via MAC control element (CE) signaling, as shown by reference numeral 845. The UE then receives the PDCCH based on the beam information included in the TCI states indicated by the MAC CE signaling.

[0274] Figure 9 A schematic diagram of the TCI indication MACCE signaling structure for PDCCH DMRS in a wireless communication system according to an embodiment of the present disclosure is shown.

[0275] Reference Figure 9 The TCI indication MAC CE signaling used for PDCCH DMRS is configured by 2 bytes (16 bits) and includes 1 bit reserved bit (R) 910, 5 bits serving cell ID 915, 2 bits BWP ID 920, 2 bits CORESETID 925 and 6 bits TCI status ID 930.

[0276] Figure 10 An example schematic diagram of beam configuration of CORESET and search space in a wireless communication system according to an embodiment of the present disclosure is shown.

[0277] Reference Figure 10The base station can indicate a TCI state 1005 from the TCI state list included in the configuration of CORESET 1000 via MAC CE signaling. Then, before indicating another TCI state to CORESET 1000 via another MAC CE signaling, the UE assumes that the same QCL information (TCI state 1005, beam #1) is applied to one or more search spaces 1010, 1015, and 1020 connected to CORESET 1000. Regarding the above PDCCH beam allocation method, it is difficult to indicate beam changes earlier than the MAC CE signaling delay. Another disadvantage is that the same beam is applied to each CORESET regardless of the characteristics of the search space, making flexible PDCCH beam management difficult. In the following description of embodiments of the present disclosure, embodiments of the present disclosure provide a more flexible PDCCH beam configuration and management method. In the following description of embodiments of the present disclosure, some distinguishable examples are provided for ease of description, but these examples are not mutually exclusive and can be appropriately combined with each other depending on the application.

[0278] The base station can configure one or more TCI states for a specific CORESET for the UE, and can activate one of the configured TCI states via a MAC CE activation command. For example, {TCI state #0, TCI state #1, TCI state #2} is configured as CORESET #1 as the TCI state, and the base station can send a command to the UE via MAC CE to activate TCI state #0 as the TCI state of CORESET #1. Based on the activation command for the TCI state received via MAC CE, and based on the QCL information in the activated TCI state, the UE can correctly receive the DMRS in CORESET #1.

[0279] Regarding a CORESET (CORESET#0) configured with index 0, when the UE fails to receive a MAC CE activation command regarding the TCI state of CORESET#0, it can be assumed that the UE was in the initial access procedure or a non-contention-based random access procedure not triggered by a PDCCH command with the identified SS / PBCH block QCL regarding the DMRS transmitted in CORESET#0.

[0280] Regarding a CORESET (CORESET#X) configured with a non-zero index, when the TCI state for CORESET#X is not configured to the UE, or when one or more TCI states are configured to the UE but the UE fails to receive the MAC CE activation command to activate one of the TCI states, it can be assumed that the UE, during the initial access process, identifies the SS / PBCH block QCL regarding the DMRS sent in CORESET#X.

[0281] [PDSCH: Regarding Frequency Resource Allocation]

[0282] Figure 11 An example schematic diagram illustrating the frequency axis allocation of the PDSCH in a wireless communication system according to an embodiment of the present disclosure is shown.

[0283] Figure 11 This is a schematic diagram illustrating three frequency axis resource allocation methods: Type 0 11-00, Type 1 11-05, and Dynamic Switching 11-10. These three methods can be configured via higher layers in the NR wireless communication system.

[0284] refer to Figure 11 When the UE is configured to use only resource type 0 (type 0 11-00) via higher-layer signaling, a portion of the DCI for allocating PDSCH to the UE includes a bitmap consisting of NRBG bits. The conditions for this are described below. Here, NRBG represents the number of resource block groups (RBGs) determined by the BWP size allocated according to the BWP indicator and the higher-layer parameter rbg-Size (rbg-size) as shown in Table 15-1 below, and data is sent to the RBG indicated by bitmap 1.

[0285] [Table 15-1]

[0286] Bandwidth Configuration 1 Configuration 2 1-36 2 4 37-72 4 8 73-144 8 16 145-275 16 16

[0287] When the UE is configured to use only resource type 1 (type 1 11-05) via higher-layer signaling, the portion of the PDSCH allocated by the DCI to the UE may include [the following information is missing from the original text]. Frequency axis resource allocation information consisting of bits. The conditions will be described below. Therefore, the base station can configure the starting virtual resource block (VRB) 11-20 and the length of the frequency axis resources 11-25 continuously allocated from it.

[0288] When a UE is configured to use both resource type 0 and resource type 1 (dynamic handover 11-10) via higher-layer signaling, the portion of the PDSCH allocated to the UE by the DCI includes frequency axis allocation information. This information consists of bits 11-35, the larger of the payload 11-15 used to configure resource type 0 and the payload 11-20 (start VRB 11-25) used to configure resource type 1. The conditions for this will be described below. At this time, a bit can be added to the beginning of the frequency axis resource allocation information in the DCI (most significant bit (MSB)). A value of 0 for the corresponding bit indicates the use of resource type 0, and a value of 1 for the corresponding bit indicates the use of resource type 1.

[0289] [PDSCH / PUSCH: Regarding Time Resource Allocation]

[0290] The following section describes a method for allocating time-domain resources for data channels in next-generation mobile communication systems (5G or NR systems).

[0291] The base station can configure tables of time-domain resource allocation information for PDSCH and PUSCH to the UE via higher-layer signaling (e.g., RRC signaling). For PDSCH, a table consisting of up to 16 entries (maxNrofDL-Allocations) can be configured, while for PUSCH, a table consisting of up to 16 entries (maxNrofUL-Allocations) can be configured. According to embodiments of this disclosure, the time-domain resource allocation information may include PDCCH to PDSCH time slot timing (corresponding to the time interval in a time slot unit between the time point of receiving the PDCCH and the time point of transmitting the PDSCH scheduled by the received PDCCH, indicated by K0), PDCCH to PUSCH time slot timing (corresponding to the time interval in a time slot unit between the time point of receiving the PDCCH and the time point of transmitting the PUSCH scheduled by the received PDCCH, indicated by K2), information about the position and length of the start symbol for scheduling PDSCH or PUSCH within a time slot, and the mapping type of PDSCH or PUSCH. For example, information such as Table 15-2 or 15-3 below can be sent from the base station to the UE.

[0292] [Table 15-2]

[0293]

[0294] [Table 15-3]

[0295]

[0296] The base station can notify the UE of one of the entries in the table of time-domain resource allocation information via L1 signaling (e.g., DCI) (e.g., indicated by the "Time-Domain Resource Allocation" field within the DCI). Based on the DCI received from the base station, the UE can obtain time-domain resource allocation information regarding the PDSCH or PUSCH.

[0297] Figure 12 A schematic diagram illustrating an example of time axis resource allocation for a PDSCH in a wireless communication system according to an embodiment of the present disclosure is shown.

[0298] Reference Figure 12 The base station can determine the subcarrier spacing (SCS) of the data channel and control channel by using higher-layer configuration. PDSCH and μPDCCH The time axis position of the PDSCH resource is indicated by the value of the scheduling offset K0 and the OFDM symbol start position 12-00 and length 12-05 in a time slot dynamically indicated by DCI.

[0299] Reference Figure 13A The subcarrier spacing in the data channel and control channel is the same (μ). PDSCH =μ PDCCH In case 13-00, the time slot numbers used for data and control are the same, so the base station and UE can generate scheduling offsets based on predetermined time slot offsets. On the other hand, when the subcarrier spacing of the data channel and control channel is different (μ...),... PDSCH ≠μ PDCCH In case 13-05, the time slot numbers used for data and control are different, so the base station and UE can generate scheduling offsets based on the subcarrier spacing of the PDCCH and according to the predetermined time slot offset.

[0300] [About SRS]

[0301] Next, an uplink channel estimation method using the UE's Sounding Reference Signal (SRS) transmission will be described. The base station can configure at least one SRS configuration for each uplink BWP and at least one SRS resource set for each SRS configuration for the UE to transmit configuration information for SRS transmission.

[0302] For example, the base station and the UE can exchange higher signaling information as follows to transmit information about the SRS resource set:

[0303] srs-ResourceSetId(srs-resourcesetId): SRS resource set index;

[0304] srs-ResourceIdList(srs-resourceId list): A collection of SRS resource indexes referenced by an SRS resource set.

[0305] resourceType: The timeline transmission configuration of the SRS resource referenced by the SRS resource set. It can be configured as periodic, semi-persistent, or aperiodic. When configured as periodic or semi-persistent, it can provide associated CSI-RS information based on where the SRS resource set is used. When configured as aperiodic, it can provide an aperiodic SRS resource trigger list and slot offset information, and can provide associated CSI-RS information based on where the SRS resource set is used.

[0306] Usage: Configuration regarding where the SRS resources referenced by the SRS resource set are used, and can be configured as beam management, codebook, non-codebook, and antenna switching; and

[0307] alpha, p0, pathlossReferenceRS, srs-PowerControlAdjustmentStates: Provides parameter configuration for the transmit power control of the SRS resources referenced by the SRS resource set.

[0308] The UE can interpret the SRS resources included in the set of SRS resource indexes referenced by the SRS resource set, and the information configured in the SRS resource set.

[0309] Furthermore, the base station and UE can send and receive higher-layer signaling information to transmit individual configuration information regarding SRS resources. For example, the individual configuration information regarding SRS resources may include time-frequency axis mapping information within the time slots of the SRS resources, and the time-frequency axis mapping information may include information regarding frequency hopping within or between time slots of the SRS resources. Additionally, the individual configuration information regarding SRS resources may include the time-axis transmission configuration of the SRS resources, and may be configured as periodic, semi-persistent, or aperiodic. The individual configuration information may be limited to having the same time-axis transmission configuration as the SRS resource set that includes the SRS resources. When the time-axis transmission configuration of the SRS resources is configured as periodic or semi-persistent, the SRS resource transmission period and time slot offset (e.g., periodicityAndOffset) may be additionally included in the time-axis transmission configuration.

[0310] The base station can activate, deactivate, or trigger SRS transmissions in the UE via higher-layer signaling, including RRS signaling or MAC CE signaling, or via L1 signaling (e.g., DCI). For example, the base station can activate or deactivate periodic SRS transmissions in the UE via higher-layer signaling. The base station can indicate an SRS resource set, where the resourceType is configured to be periodically activated via higher-layer signaling, and the UE can transmit SRS resources referenced by the activated SRS resource set. The time-frequency axis resource mapping in the time slots of the transmitted SRS resources follows the resource mapping information configured in the SRS resources, and the time slot mapping, including the transmission period and time slot offset, follows the periodicityAndOffset configured in the SRS resources. Furthermore, the spatial domain transmission filter applied to the transmitted SRS resources can reference spatial relationship information configured in the SRS resources or associated CSI-RS information configured in the SRS resource set including the SRS resources. The UE can transmit SRS resources in the uplink BWP regarding periodic SRS resources activated via higher-layer signaling.

[0311] For example, a base station can activate or deactivate semi-persistent SRS transmissions in a UE via higher-layer signaling. The base station can indicate the SRS resource set to be activated via MAC CE signaling, and the UE can transmit SRS resources referenced by the activated SRS resource set. The SRS resource set activated via MAC CE signaling can be limited to those where resourceType is configured as semi-persistent. The time-frequency axis resource mapping in the timeslots of the transmitted SRS resources follows the resource mapping information configured in the SRS resources, and the timeslot mapping, including the transmission period and timeslot offset, follows the periodicityAndOffset configured in the SRS resources.

[0312] Furthermore, the spatial domain transmission filter applied to the transmitted SRS resources can refer to spatial relationship information configured in the SRS resources or associated CSI-RS information configured in the SRS resource set including the SRS resources. When spatial relationship information is configured in the SRS resources, the spatial domain transmission filter can be determined without following the spatial relationship information. Here, the configuration information regarding spatial relationship information can be sent via MAC CE signaling used to activate semi-persistent SRS transmission, and the spatial domain transmission filter can be determined by referring to the spatial relationship information. The UE can transmit SRS resources in the uplink BWP activated with respect to semi-persistent SRS resources activated via higher-layer signaling.

[0313] For example, a base station can trigger aperiodic SRS transmission in a UE via a DCI. The base station can indicate one of the aperiodic SRS resource triggers (Aperiodic SRS-ResourceTrigger) via the SRS Request field of the DCI. The UE can interpret that the SRS resource set including the aperiodic SRS resource trigger indicated by the DCI has already been triggered in the aperiodic SRS resource trigger list in the configuration information of the SRS resource set. The UE can transmit the SRS resource referenced by the triggered SRS resource set. The time-frequency axis resource mapping in the timeslot of the transmitted SRS resource can follow the resource mapping information configured in the SRS resource. Furthermore, the timeslot mapping of the transmitted SRS resource can be determined by the timeslot offset between the SRS resource and the PDCCH including the DCI, and this timeslot offset can refer to one or more values ​​included in the set of timeslot offsets configured in the SRS resource set.

[0314] Specifically, the slot offset between the SRS resource and the PDCCH including the DCI can apply the value indicated by the time-domain resource allocation field of the DCI in the slot offset set (or multiple offset values) included in the slot offset set configured by the SRS resource set. Furthermore, the spatial domain transmission filter applied to the transmitted SRS resource can reference spatial relationship information configured in the SRS resource or associated CSI-RS information configured in the SRS resource set including the SRS resource. The UE can transmit the SRS resource in an uplink BWP activated with respect to an aperiodic SRS resource triggered via the DCI.

[0315] When a base station triggers aperiodic SRS transmission in a UE via DCI, the minimum time interval between the PDCCH of the DCI that triggers the aperiodic SRS transmission and the transmitted SRS may be required for the UE to send SRS by applying configuration information about SRS resources. The time interval for the UE's SRS transmission can be defined by the number of symbols between the last symbol of the PDCCH of the DCI that triggers the aperiodic SRS transmission and the first symbol to which the first transmitted SRS resource is mapped. The minimum time interval can be determined by referring to the PUSCH preparation time required for the UE to prepare for PUSCH transmission.

[0316] Furthermore, the minimum time interval can have different values ​​depending on the use of the SRS resource set, including the SRS resources to be transmitted. For example, the minimum time interval can refer to the UE's PUSCH preparation time and can be determined as N2 symbols, defined based on the UE's processing capabilities. Additionally, when the SRS resource set is configured for codebook or antenna handover, the minimum time interval can be determined as N2 symbols, taking into account the use of the SRS resource set including the SRS resources to be transmitted; and when the SRS resource set is configured for non-codebook or beam management, the minimum time interval can be determined as N2+14 symbols. When the time interval used for aperiodic SRS transmission is equal to or greater than the minimum time interval, the UE can transmit aperiodic SRS; and when the time interval used for aperiodic SRS transmission is less than the minimum time interval, the UE can ignore the DCI that triggers aperiodic SRS.

[0317] [Table 16-1]

[0318]

[0319] By referencing a reference signal, the spatialRelationInfo configuration information in Table 16-1 above can apply the beam information of the reference signal to the beam used for SRS transmission. For example, the spatialRelationInfo configuration may include the information shown in Table 16-2 below.

[0320] [Table 16-2]

[0321]

[0322] Referring to the `spatialRelationInfo` configuration, the SS / PBCH block index, CSI-RS index, or SRS index can be configured as the index of a reference signal to be referenced, so that beam information of a specific reference signal can be used. The higher signaling `referenceSignal` is configuration information indicating which reference signal is referenced for beam information in SRS transmission, where `ssb-Index` represents the SS / PBCH block index, `csi-RS-Index` represents the CSI-RS index, and `srs` represents the SRS index. When the higher signaling `referenceSignal` value is configured as `ssb-Index`, the UE can apply the receive beam used when receiving the SS / PBCH block corresponding to `ssb-Index` as the transmission beam for SRS transmission. When the higher signaling `referenceSignal` value is configured as `csi-RS-Index`, the UE can apply the receive beam used when receiving the CSI-RS corresponding to `csi-RS-Index` as the transmission beam for SRS transmission. When the value of the higher signaling referenceSignal is configured as srs, the UE can apply the receive beam used when receiving the SRS corresponding to srs as the transmission beam for SRS transmission.

[0323] [PUSCH: Regarding the transmission scheme]

[0324] Next, the scheduling scheme for PUSCH transmissions will be described. PUSCH transmissions can be dynamically scheduled by DCI UL authorization, or they can be operated by configured authorization type 1 or type 2. Dynamic scheduling instructions for PUSCH transmissions are enabled via DCI format 0_0 or 0_1.

[0325] The configured license type 1 PUSCH transmission can be quasi-statically configured by receiving the configuredGrantConfig (including the rrc-ConfiguredUplinkGrant from Table 16-3) via higher signaling, without receiving the UL grant in the DCI. After receiving the configuredGrantConfig (excluding the rrc-ConfiguredUplinkGrant from Table 16-3), the configured license type 2 PUSCH transmission can be semi-persistently scheduled by the UL grant in the DCI via higher signaling. When the PUSCH transmission operates with the configured grant, the parameters applied to the PUSCH transmission are applied via the higher signaling configuredGrantConfig from Table 16-3, except for the scaling of dataScramblingIdentityPUSCH, txConfig, codebookSubset, maxRank, and UCI-OnPUSCH provided via the higher signaling pusch-Config from Table 16-4. When the transformPrecoder is provided to the UE in the configuredGrantConfig of the higher signaling in Table 16-3, the UE applies tp-pi2BPSK in pusch-Config in Table 16-4 for PUSCH transmissions with configured permitted operation.

[0326] [Table 16-3]

[0327]

[0328] Next, the PUSCH transmission method will be described. The DMRS antenna port used for PUSCH transmission is the same as the antenna port used for SRS transmission. PUSCH transmission can follow either a codebook-based or non-codebook-based transmission method, depending on whether the higher signaling value of pusch-Config in Table 16-4 is codebook-based or non-codebook-based.

[0329] As described above, PUSCH transmissions can be dynamically scheduled via DCI format 0_0 or 0_1, and can be quasi-statically configured via configured permissions. When the UE is instructed regarding PUSCH transmission scheduling via DCI format 0_0, the UE can perform beam configuration for PUSCH transmissions using a pucch-spatialRelationInfoID (pucch-spatial relation information ID) corresponding to a UE-specific PUCCH resource that corresponds to the smallest ID in the uplink BWP active in the serving cell. In this case, PUSCH transmissions are based on a single antenna port. In a BWP without a configured PUCCH resource including pucch-spatialRelationInfo, the UE does not expect scheduling for PUSCH transmissions via DCI format 0_0. When the UE does not configure txConfig in pusch-Config in Table 16-4, the UE does not expect scheduling via DCI format 0_1.

[0330] [Table 16-4]

[0331]

[0332] Next, codebook-based PUSCH transmission will be described. Codebook-based PUSCH transmission can be dynamically scheduled via DCI format 0_0 or 0_1, or it can operate quasi-statically via configured permissions. When codebook-based PUSCH is dynamically scheduled by DCI format 0_1 ​​or quasi-statically configured by configured permissions, the UE determines the precoder for PUSCH transmission based on the SRS Resource Indicator (SRI), Transport Precoding Matrix Indicator (TPMI), and transport rank (PUSCH transport layer number).

[0333] Here, the SRI can be provided via the SRS Resource Indicator field in the DCI or via the srs-ResourceIndicator (SRS-Resource Indicator) in higher signaling. During codebook-based PUSCH transmission, the UE is configured with at least one SRS resource and can be configured with up to two SRS resources. When an SRI is provided to the UE via the DCI, the SRS resource indicated by the SRI represents the SRS resource corresponding to the SRI among the SRS resources transmitted prior to the PDCCH including the SRI. Furthermore, the TPMI and transport rank can be provided via the Precoding Information and Layer Number fields in the DCI, or configured via the precodingAndNumberOfLayers field in higher signaling. The TPMI is used to indicate the precoder applied to the PUSCH transmission. When the UE is configured with one SRS resource, the TPMI is used to indicate the precoder to be applied to that configured SRS resource. When the UE is configured with multiple SRS resources, the TPMI is used to indicate the precoder to be applied to the SRS resources indicated by the SRI.

[0334] The precoder used for PUSCH transmission is selected from the uplink codebook, which has the number of antenna ports equal to the nrofSRS-Ports (number of SRS - ports) value of the higher signaling in the SRS-Config. In codebook-based PUSCH transmission, the UE determines the codebook subset based on the codebookSubset of the higher signaling in the TPMI and push-Config. Based on the UE capabilities reported to the base station, the codebook subset in push-Config that represents higher signaling can be configured as fullyAndPartialAndNonCoherent, PartialAndNonCoherent, or NonCoherent. When the UE reports partialAndNonCoherent as a UE capability, the UE does not expect the codebookSubset value of the higher signaling to be configured as fullyAndPartialAndNonCoherent. Furthermore, when the UE reports incoherence as a UE capability, the UE does not expect the codebookSubset value of the higher signaling to be configured as fullyAndPartialAndNonCoherent or partiallyAndNonCoherent. When the nrofSRS-Ports of the higher signaling in the SRS-ResourceSet indicates two SRS antenna ports, the UE does not expect the codebookSubset value of the higher signaling to be configured as partiallyAndNonCoherent.

[0335] A UE can be configured with an SRS resource set, where the usage values ​​of higher signaling in the SRS-ResourceSet are configured in the codebook, and an SRS resource in the SRS resource set can be indicated by an SRI. When several SRS resources are configured in the SRS resource set, and the usage values ​​of higher signaling in the SRS-ResourceSet are configured in the codebook, the UE expects the value of nrofSRS-Ports of the higher signaling in the SRS-Resource to be the same for all SRS resources.

[0336] The UE transmits one or more SRS resources included in the SRS resource set to the base station. In this SRS resource set, the usage value is configured according to the codebook of the higher signaling. The base station selects one of the SRS resources transmitted by the UE and instructs the UE to perform PUSCH transmission by using the transmission beam information of the selected SRS resource. Here, in codebook-based PUSCH transmission, the SRI is used as information for indexing the selection of an SRS resource and is included in the DCI. Furthermore, the base station includes the TPMI and rank information instructing the UE to use for PUSCH transmission in the DCI. The UE performs PUSCH transmission by using the SRS resource indicated by the SRI, applying a precoder indicated by the rank, and the TPMI indicated by the transmission beam based on the SRS resource.

[0337] Next, non-codebook-based PUSCH transmissions will be described. Non-codebook-based PUSCH transmissions can be dynamically scheduled via DCI format 0_0 or 0_1, or they can operate quasi-statically via configured permissions. When at least one SRS resource is configured in the SRS resource set, where the higher signaling usage value in the SRS-ResourceSet is configured as non-codebook, the UE can receive scheduled non-codebook-based PUSCH transmissions via DCI format 0_1.

[0338] Regarding the higher signaling usage value in the SRS-ResourceSet being configured as an uncoded SRS resource set, the UE can receive the configuration of a connected non-zero power (NZP) CSI-RS resource. The UE can perform precoder calculations for SRS transmissions via measurements of the NZP CSI-RS resources connected to the SRS resource set. The UE does not expect the precoder information for SRS transmissions to be updated when the difference between the last received symbol of the aperiodic NZP CSI-RS resource connected to the SRS resource set and the first symbol of the aperiodic SRS transmission is less than 42 symbols.

[0339] When the resourceType value of the higher signaling in the SRS-ResourceSet is configured as aperiodic, the connected NZP CSI-RS is indicated by an SRS request, which is a field in DCI format 0_1 ​​or 1_1. Here, when the connected NZPCSI-RS resource is an aperiodic NZP CSI-RS resource, the presence of a connected NZP CSI-RS is indicated by the SRS request value being a field in DCI format 0_1 ​​or 1_1 if it is not 00. In this case, the corresponding DCI does not indicate cross-carrier or cross-BWP scheduling. Furthermore, when the SRS request value indicates the presence of an NZP CSI-RS, the NZP CSI-RS is located on a time slot transmitting a PDCCH including the SRS request field. Here, the TCI state configured in the scheduled subcarrier is not configured as QCL-type D.

[0340] When configuring periodic or semi-persistent SRS resource sets, the connected NZP CSI-RS can be indicated by the associated CSI-RS in the SRS-ResourceSet, which is higher signaling. Regarding non-codebook-based transmissions, the UE does not expect the spatialRelationInfo, which is higher signaling as an SRS resource, and the associated CSI-RS in the SRS-ResourceSet, which is higher signaling, to be configured together.

[0341] When multiple SRS resources are configured, the UE can determine the precoder and transmission rank to be applied to PUSCH transmission based on the SRI indicated by the base station. Here, the SRI can be indicated by the SRS Resource Indicator field in the DCI, or configured via the srs-ResourceIndicator in higher signaling. Similar to codebook-based PUSCH transmission, when the UE receives the SRI via the DCI, the SRS resource indicated by the SRI represents the SRS resource corresponding to the SRI among the SRS resources transmitted before the PDCCH including the SRI. The UE can use one or more SRS resources for SRS transmission, and the maximum number of SRS resources that can be transmitted simultaneously from the same symbol in an SRS resource set is determined by the UE capability reported by the UE to the base station. Here, the SRS resources transmitted simultaneously by the UE occupy the same RB. The UE configures one SRS port for each SRS resource. Only one SRS resource set can be configured, where the usage value (higher signaling) in the SRS-ResourceSet is configured as non-codebook, and up to four SRS resources can be configured for non-codebook-based PUSCH transmission.

[0342] The base station sends an NZPCSI-RS connected to the SRS resource set to the UE. Based on measurements during the reception of the NZPCSI-RS, the UE calculates a precoder to be used for the transmission of one or more SRS resources in the SRS resource set. When sending one or more SRS resources in the SRS resource set to the base station, the UE applies the calculated precoder, which is configured to be non-coded, and the base station selects one or more SRS resources from the received one or more SRS resources. Here, in non-codebook-based PUSCH transmission, SRI represents an index that can represent one SRS resource or a combination of multiple SRS resources, and the SRI is included in the DCI. In this case, the number of SRS resources indicated by the SRI sent by the base station can be the number of transmission layers of the PUSCH, and the UE transmits the PUSCH by applying a precoder for SRS resource transmission to each layer.

[0343] [PUSCH: Preparation time]

[0344] Next, the PUSCH preparation time will be described. When the base station schedules the UE to transmit PUSCH using DCI format 0_0 or DCI format 0_1, the UE can request the PUSCH preparation time for transmitting PUSCH by applying the transmission method indicated via DCI (transmission precoding method of SRS resources, transmission layer number, and spatial domain transmission filter). In NR, the PUSCH preparation time is defined with this in mind. The UE's PUSCH preparation time can be followed by Equation 3 below.

[0345] [Equation 3]

[0346] T proc,2 =max((N2+d 2，1 +d2)(2048+144)K2 -μ T c +T ext +T switch d 2,2 )

[0347] T proc,2 Each variable in the table can have the following meanings:

[0348] N2: The number of symbols determined based on parameter μ and UE processing capability 1 or 2 based on the UE's capabilities. When UE processing capability 1 is reported based on the UE's capabilities, N2 can have the value in Table 16-5, and when UE processing capability 2 is reported and its availability is configured via higher-layer signaling, N2 can have the value in Table 16-6.

[0349] [Table 16-5]

[0350] μ <![CDATA[PUSCH preparation time N2 [symbols]]]> 0 10 1 12 2 23 3 36

[0351] [Table 16-6]

[0352] μ <![CDATA[PUSCH preparation time N2 [symbols]]]> 0 5 1 5.5 2 11 of frequency range 1

[0353] d 2,1 When the resource elements of the first OFDM symbol transmitted by PUSCH are all DM-RS, the symbol count is determined to be 0; otherwise, it is 1.

[0354] k: 64;

[0355] μ: Use to increase T proc,2 μ DL and μ UL One of them. μ DL This indicates the parameterization of the downlink transmitted on it, including the PDCCH of the DCI used for scheduling PUSCH, and μ UL This represents the parameters of the uplink on which PUSCH is transmitted;

[0356] T C : 1 / (Δf max ·N f ), Δf max =480·10 3 Hz, N f =4096|;

[0357] d 2,2 When the DCI used to schedule PUSCH indicates a BWP handover, it follows the BWP handover time; otherwise, it is 0.

[0358] d2: When the OFDM symbols of a PUSCH with a higher priority index and a PUCCH with a lower priority index overlap in time, the value of d2 for the PUSCH with the higher priority index is used. Otherwise, d2 is 0.

[0359] T Text When the UE uses the shared spectrum channel access scheme, the UE calculates T. Text This can be applied to the PUSCH preparation process time. In other words, assume T Text =0; and

[0360] T switch When the uplink handover interval is triggered, T switch It is assumed to be a switching interval time. Otherwise, assume T switch =0;

[0361] Considering the timeline resource mapping information of the PUSCH scheduled via DCI and the timing advance (TA) effect between the uplink and downlink, when the first symbol of the PUSCH starts before the first uplink symbol, the base station and UE determine that the PUSCH preparation process time is insufficient, where the CP starts from the last symbol T of the PDCCH, which includes the DCI used to schedule the PUSCH. proc,2 Then it begins. Otherwise, the base station and UE determine that the PUSCH preparation process time is sufficient. When the PUSCH preparation process time is sufficient, the UE sends the PUSCH, and when the PUSCH preparation process time is insufficient, the UE can ignore the DCI used to schedule the PUSCH.

[0362] Next, PUSCH repetition will be described. When a PUSCH transmission has been scheduled to the UE via DCI format 0_1 ​​in a PDCCH including a CRC scrambled with C-RNTI, MCS-C-RNTI, or CS-RNTI, and the UE is configured with a higher-layer signaling pusch-AggregationFactor, the same symbol allocation is applied to a number of consecutive time slots equal to the pusch-AggregationFactor, and the PUSCH transmission is limited to single-rank transmission. For example, the UE may need to repeat the same TB on consecutive time slots equal to the pusch-AggregationFactor, and apply the same time slot allocation to each time slot. Table 16-7 indicates the redundant version of the PUSCH repetition transmission applied to each time slot. When PUSCH retransmission is scheduled to the UE for multiple time slots via DCI format 0_1, and at least one symbol in the time slot for which PUSCH retransmission is performed is indicated as a downlink symbol according to the higher-layer signaling tdd-UL-DL-ConfigurationCommon (tdd-UL-DL-ConfigurationCommon) or tdd-UL-DL-ConfigurationDedicated (tdd-UL-DL-ConfigurationDedicated) information, the UE does not perform PUSCH transmission on the time slot where the corresponding symbol is located.

[0363] [Table 16-7]

[0364]

[0365] [PUSCH: Regarding duplicate transfers]

[0366] The following section describes in detail the retransmission of uplink data channels in 5G systems. As a method for retransmitting uplink data channels, 5G systems support two types: PUSCH retransmission type A and PUSCH retransmission type B. A UE can be configured with either PUSCH retransmission type A or B via higher-layer signaling.

[0367] PUSCH Repeat Transfer Type A

[0368] As mentioned above, the position and symbol length of the start symbol of the uplink data channel can be determined by the time-domain resource allocation method in a time slot, and the base station can notify the UE of the number of repeated transmissions through higher-layer signaling (e.g., RRC signaling) or L1 signaling (e.g., DCI).

[0369] Based on the number of repeated transmissions received from the base station, the UE can repeatedly transmit uplink data channels in consecutive time slots. These uplink data channels have the same start symbol and length as the configured uplink data channels. Here, when at least one symbol of a time slot configured by the base station for the downlink to the UE or a symbol of an uplink data channel configured for the UE is set to downlink, the UE omits uplink data channel transmissions but counts the number of repeated transmissions of the uplink data channel.

[0370] Repeated transmission type B

[0371] As described above, the start symbol and length of the uplink data channel can be determined by the time-domain resource allocation method in a time slot, and the base station can notify the UE of the number of retransmissions by higher signaling (e.g., RRC signaling) or L1 signaling (e.g., DCI).

[0372] First, based on the configured start symbol and length of the uplink data channel, the nominal repetition of the uplink data channel is determined as follows. The time slot at which the nth nominal repetition begins is determined by... Provided, and the symbol starting from this time slot is provided by Provided. The time slot at the end of the nth nominal repetition is provided by... Provided, and the symbol at the end of that time slot is provided by Provided. Here, n is from 0 to numberofrepetitions-1 (number of repetitions-1), S represents the start symbol of the configured uplink data channel, and L represents the symbol length of the configured uplink data channel. K s This indicates the time slot at which the PUSCH transmission begins, and This indicates the number of symbols in each time slot.

[0373] The UE identifies invalid symbols for PUSCH repetition type B. Symbols configured for downlink via tdd-UL-DL-ConfigurationCommon or tdd-UL-DL-ConfigurationDedicated are identified as invalid symbols for PUSCH repetition type B. Furthermore, invalid symbols can be configured by higher-layer parameters (e.g., InvalidSymbolPattern). Higher-layer parameters (e.g., InvalidSymbolPattern) can provide a symbol-level bitmap over one or two time slots to configure invalid symbols. In the bitmap, 1 represents an invalid symbol.

[0374] Furthermore, the cycle and pattern of the bitmap can be configured via higher-level parameters (e.g., periodicityAndPattern). When a higher-level parameter (e.g., InvalidSymbolPattern) is configured and either InvalidSymbolPatternIndicator-ForDCIFormat0_1 or InvalidSymbolPatternIndicator-ForDCIFormat0_2 indicates 1, the UE applies the invalid symbol pattern. When the parameter indicates 0, the UE does not apply the invalid symbol pattern. When a higher-level parameter (e.g., InvalidSymbolPattern) is configured and neither InvalidSymbolPatternIndicator-ForDCIFormat0_1 nor InvalidSymbolPatternIndicator-ForDCIFormat0_2 is configured, the UE applies the invalid symbol pattern.

[0375] After identifying invalid symbols, for each nominal repeat, the UE may treat all symbols except the invalid ones as valid symbols. A nominal repeat may include one or more actual repeats when each nominal repeat includes at least one valid symbol. Here, each actual repeat may include a consecutive set of valid symbols available for PUSCH repeat transmission type B within a time slot.

[0376] Figure 13BAn example of PUSCH repetition type B in a wireless communication system according to an embodiment of this disclosure is shown. For the start symbol S of the uplink data channel, the UE can be configured to 0; for the length L of the uplink data channel, the UE can be configured to 14; and for the number of repetitions, the UE can be configured to 16. In this case, nominal repetition 1301 is indicated in 16 consecutive time slots. The UE can then determine the symbols configured in each nominal repetition 1301 as invalid symbols. Furthermore, the UE determines the symbols configured as 1 in invalid symbol mode 1302 as invalid symbols. When valid symbols, rather than invalid symbols, are configured in one or more consecutive symbols in a time slot of each nominal repetition 1301, the valid symbols are transmitted via actual repetition 1303.

[0377] In addition, regarding repeated PUSCH transmissions, NR version 16 can define the following additional methods for licensed PUSCH transmissions configured beyond time slot boundaries and UL licensed PUSCH transmissions.

[0378] In one embodiment of Method 1 (micro-slot-level repetition), at least two PUSCH repetitions within a slot or beyond a consecutive slot boundary are scheduled via a UL license. Furthermore, regarding Method 1, the time-domain resource allocation information in the DCI indicates the resources for the first repetition. The time-domain resource information for the remaining repetitions can be determined based on the time-domain resource information of the first repetition and the uplink or downlink direction determined for each symbol in each slot. Each repetition occupies consecutive symbols.

[0379] In one embodiment of method 2 (multi-segment transmission), at least two PUSCH repeat transmissions in consecutive time slots are scheduled via a UL license. Here, one transmission is allocated for each time slot, and the start point or repeat length of each transmission may be different. In method 2, the time-domain resource allocation information in the DCI indicates the start point and repeat length of all repeat transmissions. Furthermore, when repeat transmissions are performed in a single time slot via method 2, each repeat transmission is performed for each set of uplink symbols when there are several sets of consecutive uplink symbols in that time slot. When there is only one set of consecutive uplink symbols in the time slot, a single PUSCH repeat transmission is performed according to the method of NR version 15.

[0380] In one embodiment of method 3, at least two repeated PUSCH transmissions in consecutive time slots are scheduled via at least two UL licenses. Here, one transmission is allocated for each time slot, and the nth UL license can be received before the PUSCH transmission scheduled by the (n-1)th UL license ends.

[0381] In one embodiment of method 4, one or more PUSCH retransmissions within a single time slot or two or more PUSCH retransmissions at consecutive time slot boundaries can be supported by a UL license or a configuration license. The number of retransmissions indicated by the base station to the UE is only a nominal value; the actual number of PUSCH retransmissions performed by the UE may be greater than the nominal number. The time-domain resource allocation information in the DCI or configuration license represents the resources for the first retransmission indicated by the base station. The time-domain resource information for the remaining retransmissions can be determined by referring to the resource information and uplink or downlink direction of the symbols of the first retransmission. When the time-domain resource information for the retransmission indicated by the base station crosses a time slot boundary or includes an uplink / downlink switching point, the retransmission can be divided into multiple retransmissions. Here, each uplink period in a time slot may include one retransmission.

[0382] [PUSCH: Frequency Hopping Process]

[0383] The frequency hopping of the uplink data channel (PUSCH) in a 5G system will be described in detail below.

[0384] In 5G, for each PUSCH repetition transmission type, two methods are supported as frequency hopping methods for the uplink data channel. First, in PUSCH repetition transmission type A, intra-slot frequency hopping and inter-slot frequency hopping are supported, and in PUSCH repetition transmission type B, inter-repetition frequency hopping and inter-slot frequency hopping are supported.

[0385] The intra-slot frequency hopping method supported in PUSCH repetitive transmission type A is a method of transmitting allocated resources in the frequency domain by changing the frequency offset of the resource configuration in two hops within a time slot. The starting RB of each hop in intra-slot frequency hopping can be indicated by Equation 4.

[0386] [Equation 4]

[0387]

[0388] In Equation 4, i = 0 and i = 1 indicate the first jump and the second jump, respectively, and RB start Indicates the starting RB in the UL BWP, and is calculated according to the frequency resource allocation method. RB offset This represents the frequency offset between two hops via higher-level parameters. The number of symbols in the first hop can be determined by... The number of symbols in the second jump can be determined by... instruct. It represents the length of PUSCH transmission in a time slot and is indicated by the number of OFDM symbols.

[0389] Next, the inter-slot frequency hopping method supported in PUSCH repetitive transmission types A and B is a method of transmitting allocated resources in the frequency domain by changing the frequency offset of the resource configuration for each time slot. In inter-slot frequency hopping, The start of the time slot period (RB) can be indicated by Equation 5.

[0390] [Equation 5]

[0391]

[0392] In equation 5, This indicates the current slot number for the multi-slot PUSCH transmission, and RB start This represents the starting RB in ULBWP, calculated according to the frequency resource allocation method. offset The frequency offset between two hops is represented by high-level parameters.

[0393] Next, the inter-repetition frequency hopping method supported by PUSCH repetition transmission type B is a method of transmitting resources allocated in the frequency domain for one or more actual repetitions in each nominal repetition by moving resources with a configured frequency offset. RB start (n) is the frequency domain index of the starting RB of one or more actual repetitions in the nth nominal repetition, which can be followed by Equation 6 below.

[0394] [Equation 6]

[0395]

[0396] In Equation 6, n represents the nominal repeating index, and RB between two hops is represented by the higher-level parameter. offset .

[0397] [About UL PTRS]

[0398] When the phaseTrackingRS, which serves as a higher-layer parameter for the phase tracking reference signal (PTRS), is configured on the higher-layer parameter DMRS-UplinkConfig and the PUSCH is transmitted to the base station, the UE can transmit PTRS for tracking the phase of the uplink channel. The process of the UE transmitting UL PTRS is determined based on whether transform precoding is performed during PUSCH transmission. When transform precoding is performed and the transformPrecoderEnabled field is configured in the higher-layer parameter PTRS-UplinkConfig, the sampleDensity in the transformPrecoderEnabled field indicates the sample density threshold indicated by NRB0 to NRB4 in the table below, and the UE can determine the PT-RS group mode for scheduling resource NRBs according to Table 17 below. Additionally, when the transform precoder is applied to PUSCH transmission, in DCI format 0_1 ​​or 0_2, the number of bits in the PTRS-DMRS association field, which indicates the association between PTRS and DMRS, is 0.

[0399] [Table 17]

[0400] Scheduled bandwidth Number of PT-RS groups Number of samples in each PT-RS group <![CDATA[N RB0 ≤N RB <N RB1 ]]> 2 2 <![CDATA[N RB1 ≤N RB <N RB2 ]]> 2 4 <![CDATA[N RB2 ≤N RB <N RB3 ]]> 4 2 <![CDATA[N RB3 ≤N RB <N RB4 ]]> 4 4 <![CDATA[N RB4 <N RB ]]> 8 4

[0401] When transform precoding is not applied to PUSCH transmission and the higher-layer parameter phaseTrackingRS is configured, the UE indicates N in the transformPrecoderDisabled field of the higher-layer parameter PTRS-UplinkConfig. RB0 To N RB1 As frequency density, and indicating ptrs-MCS1 to ptrs-MCS3 as time density. Then, the UE can, according to Tables 18-1 and 18-2, determine the MCS(l) of the scheduled PUSCH. MCS ) and RB(N RB ), respectively determine the PT-RS density (L) in the time domain. PT-RS ) and frequency domain PT-RS density (K PT-RS In Table 18-1, although ptrs-MCS4 is not explicitly declared as a higher-layer parameter, the base station and UE know that ptrs-MCS4 is 29 or 28 based on the configured MCS table.

[0402] [Table 18-1]

[0403] Scheduled MCS <![CDATA[Time density (L PT-RS ) <!-- 46 -->]]> <![CDATA[l MCS <ptrs-MCS1]]> PT-RS does not exist <![CDATA[ptrs-MCS1≤l MCS <ptrs-MCS2]]> 4 <![CDATA[ptrs-MCS2≤l MCS <ptrs-MCS3]]> 2 <![CDATA[ptrs-MCS3≤l MCS <ptrs-MCS4]]> 1

[0404] [Table 18-2]

[0405]

[0406]

[0407] When the transformation precoder is not applied to PUSCH transmission and PTRS-UplinkConfig is configured, the base station instructs the UE to use a 2-bit PTRS-DMRS association field to indicate the association between PTRS and DMRS in DCI format 0_1 ​​or 0_2. The indicated 2-bit PTRS-DMRS association field is applied to Table 19-1 or 19-2 below, depending on the maximum number of PTRS ports configured by maxNrofPorts in the higher-layer parameter PTRS-UplinkConfig. When the maximum number of PTRS ports is 1, the UE determines the association between PTRS and DMRS using Table 19-1 and the 2 bits indicated as the PTRS-DMRS association field, and transmits PTRS accordingly. When the maximum number of PTRS ports is 2, the UE determines the association between PTRS and DMRS using Table 19-2 and the 2 bits indicated as the PTRS-DMRS association field, and transmits PTRS accordingly.

[0408] [Table 19-1]

[0409] value DMRS port 0 DMRS port of the first dispatcher 1 DMRS port of the second scheduler 2 DMRS port of the third dispatch 3 DMRS port of the 4th dispatch

[0410] [Table 19-2]

[0411]

[0412] The DMRS ports in Tables 19-1 and 19-2 are determined by a table configured with higher-layer parameters and by the antenna port field indicated by the same DCI indicating PTRS-DMRS association. When the transformation precoder is not configured via a higher configuration of the PUSCH, for DMRS, dmrs-type is configured to 1, maxLength is configured to 2, and the rank of the PUSCH is configured to 2. The UE can determine the DMRS port via the bits indicated by the antenna port field and a table regarding antenna ports, as shown in Table 20 below. Table 20 is an example of an antenna port table referenced during the PUSCH configuration described above, and when the PUSCH has been configured with another parameter, the DMRS port is determined based on the bits of the antenna port field indicated by the DCI and the configured antenna port table.

[0413] [Table 20]

[0414]

[0415] The DMRS for the first to fourth scheduling in Table 19-1 are defined as the values ​​of the DMRS ports indicated by the antenna port table, mapped according to the higher-layer configuration of the DCI and the bit order of the antenna port field. For example, when the bits of the antenna port field in the DCI are 0001 and the DMRS port is determined by referring to Table 20, the scheduled DMRS ports are 0 and 1, where DMRS port 0 can be defined as the first scheduled DMRS and DMRS port 1 can be defined as the second scheduled DMRS. This can be similarly applied to DMRS ports determined by the bits of another antenna port field and the antenna port table according to another higher-layer configuration. In the DMRS ports thus defined, the UE determines a DMRS port associated with a PTRS port by referring to the bits indicated by the PTRS-DMRS association in the DCI and transmits PTRS accordingly.

[0416] In Table 19-2, the DMRS ports sharing PTRS port 0 and PTRS port 1 can be defined based on codebook-based or non-codebook-based PUSCH transmission. When the UE transmits PUSCH based on partially coherent or non-coherent codebooks, the uplink layer transmitted by PUSCH antenna ports 1000 and 1002 (antenna port numbers "1000-1011" are defined in TS 38.211) is associated with PTRS port 0, and the uplink layer transmitted by PUSCH antenna ports 1001 and 1003 is associated with PTRS port 1.

[0417] In detail, when layer 3: TPMI = 2 is selected for codebook-based PUSCH transmission, the first layer is associated with PTRS port 0 because it is transmitted by PUSCH antenna ports 1000 and 1002. The second and third layers are associated with PTRS port 1 because the second layer is transmitted by PUSCH antenna port 1001 and the third layer by PUSCH antenna port 1002. These three layers represent DMRS ports respectively: the DMRS port of the first layer corresponds to the first DMRS port of PTRS port 0 in shared table 19-2, the DMRS port of the second layer corresponds to the first DMRS port of PTRS port 1 in shared table 19-2, and the DMRS port of the third layer corresponds to the second DMRS port of PTRS port 1 in shared table 19-2.

[0418] Similarly, the DMRS port associated with PTRS port 0 and the DMRS port associated with PTRS port 1 can be determined based on TPMI and different layer numbers. When the UE transmits PUSCH based on a non-codebook, the DMRS port associated with PTRS port 0 and the DMRS port associated with PTRS port 1 can be distinguished based on the antenna port indicated by DCI and SRI. Specifically, SRS resources included in the SRS resource set (where the usage is non-coded) can be configured to be associated with either PTRS port 0 or PTRS port 1 via the higher-layer parameter ptrs-PortIndex. The base station indicates the SRS resources for non-codebook-based PUSCH transmission using the SRI. Here, the ports of the indicated SRS resources are mapped to PUSCH DMRS ports in a one-to-one manner. The association between the PUSCH DMRS port and the PTRS port is determined based on the higher-layer parameter ptrs-PortIndex of the SRS resource mapped to the DMRS port.

[0419] For example, the ptrs-PortIndex is configured to be n0, n0, n1, and n1 respectively for SRS resources 1 to 4 included in the SRS resource set using a non-codebook. Furthermore, PUSCH is indicated to be transmitted by SRI through SRS resources 1, 2, and 4, and DMRS ports 0, 1, and 2 are indicated as antenna port fields. The ports of SRS resources 1, 2, and 4 are mapped to DMRS ports 0, 1, and 2, respectively. Additionally, according to the ptrs-PortIndex in the SRS resources, DMRS ports 0 and 1 are associated with PTRS port 0, and DMRS port 2 is associated with PTRS port 1.

[0420] Therefore, in Table 19-2, DMRS port 0 corresponds to the first DMRS port sharing PTRS port 0, DMRS port 1 corresponds to the second DMRS port sharing PTRS port 0, and DMRS port 2 corresponds to the first DMRS port sharing PTRS port 1. Similarly, the DMRS port associated with PTRS port 0 and the DMRS port associated with PTRS port 1 can be determined based on different SRI values ​​and ptrs-PortIndex configuration methods in different SRS resources. As described above for two PTRS ports, the UE determines the association between DMRS ports and PTRS ports. Then, among the multiple DMRS ports associated with each PTRS port, the UE can determine the DMRS port to be associated with PTRS port 0 by referring to the most significant bit (MSB) of the PTRS-DMRS association and the DMRS port to be associated with PTRS port 1 by referring to the least significant bit (LSB) to transmit PTRS.

[0421] [Regarding UE Capability Report]

[0422] In LTE and NR, when connected to a serving base station, the UE can perform a process of reporting the capabilities it supports to the base station. In the following text, this process will be referred to as UE capability reporting.

[0423] A base station can send a UE capability request message to a UE in a connected state. The UE capability request message can include UE capability requests for each Radio Access Technology (RAT) type of the base station. UE capability requests for each RAT type can include supported frequency band combination information, etc. Furthermore, regarding UE capability request messages, multiple UE capabilities for each RAT type can be requested via a single RRC message container sent by the base station, or the base station can send UE capability request messages to the UE multiple times, including UE capability requests for each RAT type.

[0424] In other words, a UE capability query can be repeated multiple times in a single message, and the UE can configure the corresponding UE capability information message and report the message multiple times. In next-generation mobile communication systems, UE capabilities can be requested for Multi-RAT Dual Connectivity (MR-DC) and NR, LTE, and E-UTRA-NR Dual Connectivity (EN-DC). UE capability query messages are typically sent in the initial phase after the UE connects to the base station, but can be requested by the base station as needed in any situation.

[0425] Here, when the UE receives a UE capability report request from the base station, the UE configures its capabilities based on the frequency band information and RAT type requested by the base station. The method for configuring UE capabilities in the NR system will now be described.

[0426] In one embodiment, when the UE receives a list of LTE and / or NR frequency bands from the base station as a UE capability request, the UE configures a band combination (BC) for EN-DC and NR Independent (SA). In other words, the UE configures a candidate list of BCs for EN-DC and NR SA based on the frequency bands requested from the base station according to the FreqBandList. The frequency bands are prioritized according to the order specified in the FreqBandList.

[0427] In one embodiment, when a base station has requested a UE capability report by setting the "eutra-nr-only" flag or the "eutra" flag, the UE can completely remove candidates for NR SA BC from the configured BC candidate list. This operation can only be performed when the LTE base station (eNB) requests "eutra" capability.

[0428] In one embodiment, the UE removes a fallback BC from the configured list of candidate BCs. Here, a fallback BC refers to a BC that is available by removing the BC corresponding to at least one SCell from any BC, and this is possible because the BC prior to removing the BC corresponding to at least one SCell has already covered the fallback BC. This operation also applies to MR-DC, i.e., LTE bands. The remaining BCs constitute the final candidate list of BCs.

[0429] In one embodiment, the UE selects the BC to report by choosing a BC from the final candidate list of BCs based on the requested RAT type. Here, the UE configures the supportedBandCombinationList in a defined order. In other words, the UE configures the UE capabilities and BCs to be reported according to the preset RAT type order (NR->EUTRA-NR->EUTRA). Furthermore, the featureSetCombination is configured with respect to the configured supportedBandCombinationList, and a list of candidate featureSetCombinations is configured from the candidate BC list, removing fallback BCs (including capabilities of the same or lower rank) from this list. The candidate featureSetCombinations include all featureSetCombinations for NR and EUTRA-NR BCs and can be obtained from the featureSetCombinations of the UE-NR capability and UE-MRDC capability containers.

[0430] In one embodiment, when the requested rat type is eutra-nr, featureSetCombinations are included in both the UE-MRDC-capabilities and UE-NR-capabilities containers. However, the NR feature set only includes UE-NR capabilities.

[0431] After configuring UE capabilities, the UE sends a UE capability information message, including the UE capabilities, to the base station. Based on the UE capabilities received from the UE, the base station performs appropriate scheduling and transmit / receive management for the UE.

[0432] [About CA / DC]

[0433] Figure 14 A diagram illustrating the radio protocol architecture of a base station and a UE in a wireless communication system under single-cell, carrier aggregation (CA), and dual connectivity (DC) scenarios according to embodiments of the present disclosure is shown.

[0434] Reference Figure 14The radio protocol architecture of the next-generation mobile communication system may include NR Service Data Adaptation Protocol (SDAP) layers 1425 and 1470, NR Packet Data Convergence Protocol (PDCP) layers 1430 and 1465, NR Radio Link Control (RLC) layers 1435 and 1460, and NR Media Access Control (MAC) layers 1440 and 1455 for UE and NR base station (gNB), respectively.

[0435] The main functions of NR SDAP layers 1425 and 1470 may include some of the following:

[0436] Transmission of user plane data;

[0437] Mapping between QoS flows and data radio bearers (DRBs) for both DL and UL; marking QoS flow IDs in both DL and UL packets; and / or

[0438] Reflected QoS flow from UL SDAP PDU to DRB mapping.

[0439] Regarding NR SDAP layer 1425 or 1470, the UE can be configured via RRC messages to determine whether to use the header of NR SDAP layer 1425 or 1470, or whether to use the functionality of NR SDAP layer 1425 or 1470 for each NR PDCP layer 1430 or 1465, each bearer, or each logical channel. When the SDAP header is configured, the NAS reflective QoS configuration 1-bit indicator and the AS reflective QoS configuration 1-bit indicator in the SDAP header can instruct the UE to update or reconfigure the mapping information between QoS flows and data bearers in the UL and DL. The SDAP header may include a QoS flow ID indicating QoS. QoS information can be used as data processing priority information, scheduling information, etc., to support smooth service.

[0440] The main functions of NR PDCP layer 1430 or 1465 may include some of the following:

[0441] Header compression and decompression: ROHC only;

[0442] Transmission of user data;

[0443] Sequential delivery of upper-layer PDUs;

[0444] Out-of-order delivery of upper-layer PDUs;

[0445] PDCP PDU reordering for received;

[0446] Repeat detection of low-level SDUs;

[0447] Forwarding of PDCP SDU;

[0448] Encryption and decryption; and / or

[0449] Timer-based SDUs are discarded in the uplink.

[0450] The reordering function of NR PDCP layer 1430 or 1465 may represent the function of reordering PDCP PDUs received from lower layers based on PDCP sequence numbers (SNs), and may include the function of delivering data to higher layers in the reordered order. Alternatively, the reordering function of NR PDCP layer 1430 or 1465 may include the function of delivering data immediately regardless of order, the function of recording lost PDCP PDUs by reordering the order, the function of reporting the status of lost PDCP PDUs to the transmitter, and the function of requesting retransmission of lost PDCP PDUs.

[0451] The primary functions of NR RLC layer 1435 or 1460 may include at least some of the following functions:

[0452] Transmission of upper-layer PDUs;

[0453] Sequential delivery of upper-layer PDUs;

[0454] Out-of-order delivery of upper-layer PDUs;

[0455] Error correction via ARQ;

[0456] splicing, segmentation, and reassembly of RLC SDUs;

[0457] Resegmentation of RLC data PDUs;

[0458] RLC data PDU reordering:

[0459] Repeat detection;

[0460] Protocol error detection;

[0461] RLC SDU discarded; and / or

[0462] RLC reconstruction.

[0463] The sequential delivery function of NR RLC layer 1435 or 1460 represents the function of sequentially delivering RLC SDUs received from lower layers to higher layers. The sequential delivery function of NR RLC layer 1435 or 1460 may include: reassembling and delivering RLC SDUs segmented from RLC SDUs when segmented RLC SDUs are received; reordering received RLC PDUs based on the RLC SN or PDCP SN; recording lost RLC PDUs by reordering them; reporting the status of lost RLC PDUs to the transmitter; and requesting retransmission of lost RLC PDUs. The in-order delivery function of NR RLC layer 1435 or 1460 may include, when a lost RLC SDU exists, only delivering RLC SDUs preceding the lost RLC SDU sequentially to higher layers, or, when a timer expires, delivering all RLC SDUs received before the timer started sequentially to higher layers, even when a lost RLC SDU exists.

[0464] Alternatively, the in-order delivery of NR RLC layers 1435 or 1460 may include the function of sequentially delivering all currently received RLC SDUs to higher layers when a timer expires despite the absence of an RLC SDU. Furthermore, RLC PDUs may be processed in the order of reception (according to arrival order, regardless of sequence number), and RLC PDUs may be delivered out of order to NR PDCP layers 1430 or 1465 (out-of-order delivery). Segments to be received or stored in buffers may be reassembled into complete RLC PDUs and processed, and the RLC PDUs may be delivered to NR PDCP layers 1430 or 1465. NR RLC layers 1435 or 1460 may not have a cascading function, and this cascading function may be performed by NR MAC layers 1440 or 1455, or replaced by the multiplexing function of NR MAC layers 1440 or 1455.

[0465] The out-of-order delivery of NR RLC layers 1435 or 1460 represents the function of immediately delivering RLC SDUs received from lower layers to higher layers without regard to order, and may include the function of reassembling and delivering the segmented and received RLC SDUs when an RLC SDU is segmented into several RLC SDUs, and the function of recording lost RLC PDUs by storing the RLC SN or PDCP SN and reordering the received RLC PDUs.

[0466] NR MAC layer 1440 or 1455 can connect to multiple NR RLC layers 1435 or 1460 configured for a single UE, and the main functions of NR MAC layer 1440 or 1455 may include at least some of the following functions:

[0467] Mapping between logical channels and transport channels;

[0468] Multiplexing / demultiplexing of MAC SDUs;

[0469] Dispatch information report;

[0470] Error correction via HARQ;

[0471] Priority handling between logical channels of a UE;

[0472] Priority processing among UEs is achieved through dynamic scheduling;

[0473] MBMS identifier;

[0474] Transmission format selection; and / or

[0475] filling.

[0476] PHY layer 1445 or 1450 can encode and modulate higher-layer data channels into OFDM symbols and transmit OFDM symbols via radio channels, or demodulate OFDM symbols received via radio channels, perform channel decoding, and deliver OFDM symbols to higher layers.

[0477] Depending on the carrier (or cell) operation scheme, radio protocol architectures can have various detailed structures. For example, when a base station transmits data to a UE based on a single carrier (or cell), the base station and UE use a protocol architecture with a single structure at each layer, as shown by reference numeral 1400. On the other hand, when a base station transmits data to a UE based on a CA using multiple carriers in a single transmit and receive point (TRP), the base station and UE use a protocol architecture with a single structure up to the RLC layer but multiplexing the PHY layer via the MAC layer, as shown by reference numeral 1410. As another example, when a base station transmits data to a UE based on a DC using multiple carriers in multiple TRPs (e.g., MgNB or SgNB), the base station and UE use a protocol architecture with a single structure up to the RLC layer but multiplexing the PHY layer via the MAC layer, as shown by reference numeral 1420.

[0478] [About NC-JT]

[0479] According to embodiments of this disclosure, non-coherent joint transmission (NC-JT) can be used for a UE to receive PDSCH from multiple TRPs.

[0480] Unlike existing communication systems, 5G wireless communication systems can support services requiring high data rates, as well as services with very short transmission latency and high connection density. In wireless communication networks comprising multiple cells, TRPs, or beams, cooperative communication (coordinated transmission) between cells, TRPs, and / or beams can meet various service requirements by effectively implementing inter-cell, TRP, and / or beam interference control or by increasing the strength of the signal received by the UE. In the following text, for ease of description, higher-layer / L1 parameters, such as TCI status and spatial relationship information, or cells, transmission points, panels, beams, and / or transmission directions that can be distinguished by indicators such as cell ID, TRP ID, and panel ID, may be collectively referred to as TRP. Therefore, for practical applications, TRP may be appropriately replaced by one of the aforementioned terms.

[0481] JT is one of the representative transmission technologies used for cooperative communication, and it is a technique that increases the strength or throughput of the signal received by the UE by transmitting signals to the UE via multiple different cells, TRPs, and / or beams. The channel characteristics between the UE and each cell, TRP, and / or beam can vary greatly. Specifically, depending on the channel characteristics of each link between the UE and the cell, TRP, and / or beam, NC-JT supporting non-interference coding between cells, TRPs, and / or beams may require separate precoding, MCS, resource allocation, or TCI indication.

[0482] NC-JT can be applied to at least one of the downlink data channel (PDSCH), downlink control channel (PDCCH), uplink data channel (PUSCH), and uplink control channel (PUCCH). During PDSCH transmission, transmission information such as precoding, MCS, resource allocation, or TCI is indicated by DL DCI, and for NC-JT, the transmission information needs to be indicated independently for each cell, TRP, and / or beam. This is a major factor increasing the payload required for DL ​​DCI transmission and can adversely affect the reception performance of DCI in PDCCH transmission. Therefore, for JT support of PDSCH, it is necessary to carefully design the trade-off between the amount of DCI and the reception performance of control information.

[0483] Figure 15 An example schematic diagram of antenna port configuration and resource allocation for transmitting PDSCH in a wireless communication system using cooperative communication, according to an embodiment of the present disclosure, is shown.

[0484] Reference Figure 15 Examples of PDSCH transmissions are described for each technology of JT, and an example of allocating radio resources for each TRP is shown.

[0485] exist Figure 15 Example 1500 of coherent JT (C-JT) that supports phase interference coding between cells, TRPs and / or beams is shown.

[0486] In C-JT, a single data packet (PDSCH) is sent from TRP A1505 and TRP B1510 to UE 1515, and multiple TRPs perform joint precoding. This can be instructed to send DMRS through the same DMRS port so that TRP A1505 and TRP B1510 send the same PDSCH. For example, TRP A1505 and TRP B1510 can each send DMRS to UE 1515 through DMRS port A and DMRS port B, respectively. In this case, UE 1515 can receive a DCI for receiving a PDSCH based on the demodulated DMRS sent through DMRS ports A and B.

[0487] exist Figure 15 Example 1520 of NC-JT supporting non-phase interference coding between cells, TRPs and / or beams for PDSCH transmission is shown.

[0488] In NC-JT, PDSCH is transmitted to UE 1535 for each cell, TRP, and / or beam, and individual precoding can be applied to each PDSCH. Different PDSCHs or different PDSCH layers can be transmitted to UE 1535 for each cell, TRP, and / or beam to improve throughput relative to transmissions to a single cell, TRP, and / or beam. Furthermore, the same PDSCH can be repeatedly transmitted to UE 1535 for each cell, TRP, and / or beam to improve reliability relative to transmissions to a single cell, TRP, and / or beam. For ease of description, cells, TRPs, and / or beams are collectively referred to as TRPs below.

[0489] Here, various radio resource allocations can be considered for PDSCH transmission, such as the case where multiple TRPs use the same frequency and time resources 1540, the case where multiple TRPs use non-overlapping frequency and time resources 1545, and the case where multiple TRPs use partially overlapping frequency and time resources 1550.

[0490] To support NC-JT, it is possible to consider assigning DCIs of various forms, structures, and relationships to a single UE simultaneously to multiple PDSCHs.

[0491] Figure 16 An example schematic diagram of the configuration of DCI for NC-JT in a wireless communication system according to an embodiment of the present disclosure is shown, wherein each TRP sends a different PDSCH or a different PDSCH layer to the UE.

[0492] Reference Figure 16 Case #1 1600 is an example where, when N-1 different PDSCHs are transmitted from additional N-1 TRPs (TRP #1 to TRP #N-1) besides the serving TRP (TRP #0) used during a single PDSCH transmission, control information related to the PDSCHs transmitted from the additional N-1 TRPs is transmitted independently of control information related to the PDSCHs transmitted from the serving TRP. In other words, the UE can obtain control information about the PDSCHs transmitted from different TRPs (TRP #0 to TRP #N-1) via independent DCIs (DCI #0 to DCI #N-1). The formats of the independent DCIs can be the same or different from each other, and the payloads of the DCIs can be the same or different from each other. In Case #1 1600, the degree of freedom for each PDSCH control or allocation can be fully guaranteed, but when DCIs are transmitted from different TRPs, reception performance may degrade due to the coverage differences for each DCI.

[0493] Case #2 1605 is an example in which, when sending different N-1 PDSCHs from additional N-1 TRPs (TRP #1 to TRP #N-1) other than the serving TRP (TRP #0) used during a single PDSCH transmission, control information (DCI) about the PDSCHs sent from the additional N-1 TRPs is sent, and each DCI depends on the control information about the PDSCHs sent from the serving TRP.

[0494] For example, DCI#0, which is control information about PDSCH sent from the serving TRP (TRP#0), includes all information elements of DCI format 1_0, DCI format 1_1, and DCI format 1_2. However, the shortened DCI (sDCI) (sDCI#0 to sDCI#N-2), which is control information about PDSCH sent from the cooperating TRPs (TRP#1 to TRP#N-1), may include some information elements of DCI format 1_0, DCI format 1_1, and format 1_2. Therefore, because sDCI has a smaller payload than normal DCI (nDCI), which sends control information about PDSCH sent from the serving TRP, sDCI may include reserved bits compared to nDCI.

[0495] Case #2 1605 has limited PDSCH control or allocation freedom depending on the content of the information elements included in the sDCI, but because the reception performance of the sDCI is better than that of the nDCI, there may be a low probability of coverage differences for each DCI.

[0496] Case #3 1610 is an example in which, when sending different N-1 PDSCHs from additional N-1 TRPs (TRP #1 to TRP #N-1) other than the serving TRP (TRP #0) used during a single PDSCH transmission, control information about the PDSCHs of the additional N-1 TRPs is sent, and the DCI depends on the control information about the PDSCHs sent from the serving TRP.

[0497] For example, DCI#0, which is control information about PDSCH sent from the serving TRP (TRP#0), includes all information elements of DCI format 1_0, DCI format 1_1, and DCI format 1_2. For control information about PDSCH sent from cooperating TRPs (TRP#1 to TRP#N-1), some information elements of DCI format 1_0, DCI format 1_1, and DCI format 1_2 can be collected into an auxiliary DCI (sDCI). For example, the sDCI may include at least one piece of information from the cooperating TRP, such as the MSC, in frequency domain resource allocation, time domain resource allocation, and HARQ-related information. Furthermore, information not included in the sDCI, such as BWP indicators or carrier indicators, may follow the serving TRP's DCI (DCI#0, normal DCI, nDCI).

[0498] Compared to Case #1 1600 and Case #2 1605, Case #3 1610 has limited PDSCH control or allocation freedom depending on the content of the information elements included in the sDCI, but the reception performance of the sDCI can be controlled, and the complexity of blind decoding of the UE's DCI can be lower.

[0499] Case #4 1615 is an example where, when N-1 different PDSCHs are transmitted from additional N-1 TRPs (TRP #1 to TRP #N-1) besides the serving TRP (TRP #0) used during a single PDSCH transmission, control information about the PDSCHs transmitted from the additional N-1 TRPs is transmitted on the same DCI (long DCI) as the control information about the PDSCHs transmitted from the serving TRP. In other words, the UE can obtain control information about the PDSCHs transmitted from different TRPs (TRP #0 to TRP #N-1) via a single DCI. In Case #4 1615, the complexity of the UE's blind DCI decoding may be low, but the degree of freedom in PDSCH control or allocation may be limited; for example, the number of cooperating TRPs may be limited due to long DCI payload constraints.

[0500] In the following description and embodiments, sDCI can refer to various types of auxiliary DCI, such as shortened DCI, auxiliary DCI, and normal DCI including PDSCH control information sent from the cooperative TRP (DCI formats 1_0 to 1_1 above), and unless specifically stated otherwise, this description can be similarly applied to various types of auxiliary DCI.

[0501] In the following description and embodiments, cases #1 1600, #2 1605, and #3 1610, which use one or more DCIs (PDCCHs) to support NC-JT, can be distinguished as multiple PDCCH-based NC-JTs, while case #4 1615, which uses a single DCI (PDCCH) to support NC-JT, can be distinguished as a single PDCCH-based NC-JT. In multiple PDCCH-based PDSCH transmissions, the CORESET scheduling DCI for the serving TRP (TRP #0) and the CORESET scheduling DCI for the cooperating TRPs (TRP #1 to TRP #N-1) can be distinguished. To distinguish CORESETs, methods such as distinguishing CORESETs via higher-layer indicators for each CORESET or by beam configuration for each CORESET can be used. Furthermore, in a single PDCCH-based NC-JT, instead of scheduling multiple PDSCHs via a single DCI, a single PDSCH comprising multiple layers is scheduled, and multiple layers can be transmitted from multiple TRPs. Here, the connection between the layer and the TRP that transmits the layer can be indicated via the Transport Configuration Indicator (TCI) for that layer.

[0502] In embodiments of this disclosure, when applied in practice, “Cooperative TRP” can be replaced by any of a variety of terms, such as “cooperative panel”, “cooperative beam”, etc.

[0503] In embodiments of this disclosure, the phrase "when NC-JT is applied" can be interpreted differently depending on the circumstances, such as "when the UE simultaneously receives one or more PDSCHs from a BWP", "when the UE simultaneously receives PDSCHs based on two or more TCI indications from a BWP", and "when the PDSCHs received by the UE are associated with at least one DMRS port group". For ease of description, one expression is used.

[0504] In this disclosure, the radio protocol architecture of NC-JT can vary depending on the TRP deployment scenario. For example, when there is no backhaul delay or very low backhaul delay between cooperating TRPs (e.g., MgNB or SgNB), a protocol architecture such as... Figure 14The attached figure, reference numeral 1410, illustrates a method using a MAC layer-based multiplexing structure (similar to the CA method). On the other hand, when the backhaul delay between cooperative TRPs is too large to be ignored (e.g., exchanging information such as CSI, scheduling, and HARQ acknowledgment (ACK) between cooperative TRPs requires at least 2 ms), a method can be used to ensure robustness regarding delay by using an independent structure for each TRP from the RLC layer (similar to the DC method), such as... Figure 14 As shown by reference numeral 1420 in the attached figure.

[0505] UEs supporting C-JT / NC-JT can receive C-JT / NC-JT related parameters or settings from higher-level configurations and set their RRC parameters accordingly. For higher-level configurations, the UE can use UE capability parameters, such as tci-StatePDSCH. Here, the UE capability parameter (e.g., tci-StatePDSCH) can define the TCI states used for PDSCH transmission. The number of TCI states can be configured as 4, 8, 16, 32, 64, or 128 in FR1 and 64 or 128 in FR2. Within the configured number, up to 8 states can be configured via the MAC CE message, indicated by the 3 bits of the TCI field of the DCI. The maximum number of 128 represents the value indicated by maxNumberConfiguredTCIstatesPerCC (the maximum number of configured TCI states per CC) in the tci-StatePDSCH parameter included in the UE's capability signaling. In this way, a series of configuration procedures from high-level configuration to MAC CE configuration can be applied to beamforming indication or beamforming change command of at least one PDSCH in a TRP.

[0506] In the following text, for ease of description, higher-layer / L1 parameters, such as TCI status and spatial relationship information, or cell, transmission point, panel, beam, and / or transmission direction that can be distinguished by indicators such as cell ID, TRP ID, and panel ID, may be collectively referred to as TRP. Therefore, for practical applications, TRP may be appropriately replaced by one of the terms mentioned above.

[0507] Referring to the descriptions related to PUSCH above, the current Rel-15 / 16NR focuses on a single cell, a single TRP, a single panel, a single beam, and / or a single transmission direction for PUSCH repetition. Specifically, regarding PUSCH repetition, the transmission of a single TRP is considered, regardless of whether it is codebook-based or non-codebook-based. For example, in codebook-based PUSCH transmission, the UE's transmission beam can be determined by the SRI and TPMI (i.e., a single TRP) transmitted from the base station to the UE. Similarly, in non-codebook-based PUSCH transmission, the NZP CSI-RS, i.e., a single TRP, which can be configured from the base station, can be assigned to the UE, and the UE's transmission beam can be determined by the SRI transmitted from the single TRP.

[0508] Therefore, when time- and space-dependent degradation factors exist, such as congestion in the channel between the UE and a specific TRP, the expected performance of PUSCH retransmission for a single TRP may not be met. To overcome this degradation, Rel-17 or later versions can support PUSCH retransmission considering multiple TRPs. This can be a method to maximize diversity gain when considering the channel between the UE and multiple TRPs with different spatial characteristics. To support this method, the UE needs to support configurations for PUSCH retransmission to multiple TRPs. For example, configuration or indication schemes regarding multiple transmission beams, power control, etc., are needed when considering PUSCH retransmission to multiple TRPs.

[0509] Furthermore, higher-layer signaling or dynamic indication is needed to distinguish between repeated transmissions considering a single TRP as defined in Rel-15 / 16 and repeated PUSCH transmissions considering multiple TRPs newly defined in Rel-17. As a method for improving PUSCH reception performance, a method is needed to determine the interrelated transmission beams and frequency hopping such that spatial diversity gain via repeated transmissions to multiple TRPs and frequency diversity via frequency hopping are simultaneously obtained to maximize diversity gain.

[0510] When transmitting downlink or uplink data, the base station or UE can transmit PTRS, as well as downlink or uplink data and DMRS for data reception. PTRS can be used to track the phase of the transmitted signal and enhance reception performance by compensating for the phase. Specifically, in band 2 (FR2), which is a high-frequency band, although the phase error is small, it produces a very large channel estimation error, so the need for tracking and compensating for the phase error may be greater than in lower frequency bands. NR Releases 15 and 16 support this phase tracking and phase error compensation using PTRS. As mentioned above, the base station indicates the DMRS port to be associated with the PTRS via the PTRS-DMRS association field of the DCI. PTRS-DMRS association reduces phase estimation error by indicating that the PTRS is transmitted from the same port as the layer with the highest channel gain among several layers, thus improving phase estimation accuracy and channel estimation accuracy.

[0511] When supporting time-division multiplexing (TDM)-based PUSCH repetition using multiple TRPs introduced in Rel-17, the UE and channel are different for each TRP, thus requiring a PTRS to be sent for each TRP to perform phase estimation and phase error compensation. Because the channel differs for each TRP, the DMRS port for the layer with high channel gain can also differ for each TRP. The PTRS-DMRS association needs to indicate the relationship between the PTRS and DMRS for each of the multiple TRPs. However, in NR Release 15 / 16, only one PTRS-DMRS association field exists in the DCI, making it impossible to indicate the association between the PTRS and DMRS for each of the multiple TRPs. Therefore, an improved method is needed to indicate the PTRS-DMRS association field used to perform phase tracking for multiple TRPs.

[0512] In embodiments of this disclosure, processing methods for the above requirements are provided, thereby reducing transmission delay and uplink data loss during PUSCH retransmission when considering multiple TRPs. Furthermore, when an improved PTRS-DMRS association method is provided to determine the PTRS transmission information required for PUSCH retransmission considering multiple TRPs, phase tracking and phase error compensation for uplink signals can be performed for each TRP. The following will describe in detail, with reference to embodiments of this disclosure, methods for configuring or instructing the UE to repeatedly transmit PUSCH to multiple TRPs, and PTRS-DMRS association methods for multiple TRPs, for various situations.

[0513] In the following, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In this context, a base station is an entity that allocates resources to terminals and can be at least one of a gNode B (gNB), eNode B (eNB), Node B (NB), base station (BS), radio access unit, BS controller, and nodes on a network. Examples of terminals may include user equipment (UE), mobile station (MS), cellular phone, smartphone, computer, and multimedia system capable of performing communication functions. In the following, embodiments of the present disclosure will be described using a 5G system as an example; however, embodiments of the present disclosure can also be applied to other communication systems with similar technical backgrounds or channel configurations.

[0514] For example, LTE or LTE-A mobile communications and mobile communication technologies developed after 5G can be included therein. Therefore, those skilled in the art will understand that this disclosure can be applied to other communication systems with some modifications without departing from the scope of this disclosure. The content of this disclosure can be applied to frequency division duplex (FDD) or time division duplex (TDD) systems.

[0515] In describing this disclosure, detailed descriptions of relevant well-known functions or configurations may be omitted where it is believed that they may unnecessarily obscure the essence of this disclosure. Furthermore, the terms used below are defined in consideration of the functions in this disclosure, and these terms may have different meanings depending on the intent, habits, etc., of the user or operator. Therefore, these terms should be defined based on the description throughout the specification.

[0516] In the following description of embodiments of this disclosure, higher-layer signaling may be signaling corresponding to at least one or a combination of the following signaling methods:

[0517] Master Information Block (MIB);

[0518] System Information Block (SIB) or SIB X (X = 1, 2, ...);

[0519] Radio Resource Control (RRC); and / or

[0520] Media Access Control (MAC) Control Element (CE).

[0521] Furthermore, L1 signaling can be signaling corresponding to at least one or a combination of signaling methods using the following physical layer channels or signaling:

[0522] Physical Downlink Control Channel (PDCCH);

[0523] Downlink control information (DCI);

[0524] UE-specific DCI;

[0525] Group public DCI;

[0526] Public DCI;

[0527] Dispatching DCI (e.g., DCI is used to schedule downlink or uplink data);

[0528] Non-scheduled DCI (e.g., DCI is not used to schedule downlink or uplink data);

[0529] Physical Uplink Control Channel (PUCCH); and / or

[0530] Uplink Control Information (UCI).

[0531] In the following embodiments, determining the priority between A and B can be described differently as selecting the higher priority and performing the operation corresponding to the higher priority according to a predetermined priority rule, or omitting or discarding the operation with the lower priority.

[0532] The above examples will be described below through various embodiments of the present disclosure. However, the embodiments of the present disclosure are not independent, and one or more embodiments of the present disclosure may be applied simultaneously or in combination.

[0533] <First Implementation: Considering Repeated PUSCH Transmissions of Multiple TRPs>

[0534] In a first embodiment of this disclosure, a higher-layer signaling configuration and L1 signaling indication method for PUSCH retransmission considering multiple TRPs will be described. PUSCH retransmission considering multiple TRPs can be operated via a single or multiple DCI-based indications, and will be described in embodiments (1-1) and (1-2) of this disclosure. Furthermore, based on the base station configuration, the UE can support one or more PUSCH retransmissions via a single or multiple DCI-based indications, or support both methods while using them differentiatedly via L1 signaling. This will be described in embodiments (1-3) of this disclosure.

[0535] <Example (1-1): Considering PUSCH repetition transmission based on multiple TRPs of a single DCI>

[0536] As an embodiment of this disclosure, PUSCH retransmission considering multiple TRPs based on a single DCI will be described in embodiment (1-1). The UE can report the possibility of PUSCH retransmission considering multiple TRPs based on a single DCI via a UE capability report. The base station can configure which PUSCH retransmission to use for the UE that has reported its UE capabilities (e.g., UE capabilities supporting PUSCH retransmission considering multiple TRPs based on a single DCI) via higher-layer signaling. Here, the higher-layer signaling can select and configure one of PUSCH retransmission type A and PUSCH retransmission type B.

[0537] In Rel-15 / 16, for both codebook-based and non-codebook-based transmissions, PUSCH retransmissions considering a single TRP have been performed based on a single DCI. During codebook-based PUSCH transmissions, the UE can apply the same value to each PUSCH retransmission by using either the TPMI or SRI indicated by a single DCI. Similarly, during non-codebook-based PUSCH transmissions, the UE can apply the same value to each PUSCH retransmission by using the SRI indicated by a single DCI.

[0538] For example, when configuring codebook-based PUSCH transmission and PUSCH repetition type A via higher-layer signaling, and indicating the time resource allocation index via DCI (where the number of PUSCH repetitions is configured as 4, SRI index 0, and TPMI index 0), the UE applies both SRI index 0 and TPMI index 0 to each of the 4 PUSCH repetitions. Here, SRI can be associated with the transmission beam, while TPMI can be associated with the transmission precoder. Unlike PUSCH repetition considering a single TRP, PUSCH repetition considering multiple TRPs can apply the transmission beam and transmission precoder differently to the transmission of each TRP. Therefore, the UE can receive indications of multiple SRIs or TPMIs via DCI and perform PUSCH repetition considering multiple TRPs by applying multiple SRIs or TPMIs to each PUSCH repetition.

[0539] When the base station instructs the UE to consider repeated PUSCH transmissions based on multiple TRPs of a single DCI, the method for instructing multiple SRIs or TPMIs when the PUSCH transmission is codebook or non-codebook can be as follows.

[0540] [Method 1] Transmission of a single DCI including multiple SRI or TPMI fields

[0541] To support PUSCH retransmission, considering multiple TRPs based on a single DCI, the base station can send a DCI to the UE that includes multiple SRI or TPMI fields. The DCI may have a new format (e.g., DCI format 0_3) or an existing format (e.g., DCI format 0_1 ​​or 0_2), but can be configured with additional higher-layer signaling (e.g., signaling to determine the supportability of multiple SRI or TPMI fields). For example, when configuring codebook-based PUSCH transmission via higher-layer signaling, the UE can perform PUSCH retransmission by receiving a DCI with a new format (e.g., DCI format 0_3) having two SRI fields and two TPMI fields, taking into account multiple TRPs.

[0542] As another example, regarding non-codebook-based PUSCH transmissions, the UE can receive a DCI in an existing format (e.g., DCI format 0_1 ​​or 0_2) with two SRI fields, where multiple SRI fields can be configured to be supported via higher-layer signaling. When multiple SRS resources are indicated using multiple SRI fields, transmit power control parameters for the SRS resources are configured for each SRS resource set. Therefore, SRS resources can exist in different SRS resource sets to allow for different transmit power control parameters to be configured for each TRP. Thus, there may be two or more SRS resource sets where the use of higher-layer signaling is configured as either codebook-based or non-codebook-based.

[0543] Figure 17 A flowchart is shown showing the operation of a base station and a UE according to an embodiment of the present disclosure regarding the retransmission of PUSCH considering multiple TRPs based on a single DCI transmission, wherein multiple SRI or TPMI fields exist.

[0544] In Operation 1751, the UE can perform a UE capability report regarding whether PUSCH retransmission based on multiple TRPs using a single DCI is supported.

[0545] In operation 1701, the base station receives the UE capability report.

[0546] In operation 1702, the base station sends a configuration to the UE that considers repeated transmissions of PUSCH based on multiple TRPs of a single DCI. Here, the transmitted configuration may include the repeated transmission method, the number of repeated transmissions, the transmission beam mapping unit or scheme, whether multiple SRI or TPMI fields are supported, and multiple codebook or non-codebook SRS resource sets.

[0547] In operation 1752, the UE receives the configuration.

[0548] In operation 1703, the base station determines whether the number of repeated transmissions exceeds 1.

[0549] In operation 1753, the UE determines whether the number of repeated transmissions exceeds 1.

[0550] In operation 1704, when PUSCH retransmission is a codebook-based PUSCH transmission, the base station determines whether the successfully transmitted DCI includes multiple SRI fields and TPMI fields. According to another embodiment of this disclosure, when PUSCH retransmission is a non-codebook-based PUSCH transmission, the base station can determine whether the successfully transmitted DCI includes multiple SRI fields.

[0551] In operation 1754, when PUSCH retransmission is a codebook-based PUSCH transmission, the UE determines whether the successfully received (or decoded) DCI includes multiple SRI fields and TPMI fields. According to another embodiment of this disclosure, when PUSCH retransmission is a non-codebook-based PUSCH transmission, the UE can determine whether the successfully received DCI includes multiple SRI fields.

[0552] In operation 1705, if it is determined in operation 1704 that multiple SRI fields and TPMI fields are included, the base station may perform a first PUSCH reception operation. Otherwise, in operation 1706, the base station may perform a second PUSCH reception operation.

[0553] In operation 1755, when it is determined in operation 1754 that multiple SRI fields and TPMI fields are included, the UE may perform a first PUSCH transmission operation. Otherwise, in operation 1756, the UE may perform a second PUSCH transmission operation. The first PUSCH transmission operation is the operation of repeatedly transmitting PUSCH by using multiple SRI and TPMI fields in the case of codebook-based PUSCH transmission and by using multiple SRI fields in the case of non-codebook-based PUSCH transmission, and by repeatedly transmitting PUSCH by applying multiple transmission beams and / or multiple transmission precoders. The method of mapping multiple transmission beams will be described in detail with reference to the second embodiment of this disclosure. The second PUSCH transmission operation is the operation of repeatedly transmitting PUSCH by using a single SRI field and a single TPMI field in the case of codebook-based PUSCH transmission and by using a single SRI field in the case of non-codebook-based PUSCH transmission, and by repeatedly transmitting PUSCH by applying a transmission beam and / or a transmission precoder.

[0554] [Method 2] Applying improved SRI and TPMI field DCI transmission

[0555] Considering multiple TRPs based on a single DCI, in order to support PUSCH retransmission, the UE can receive a MAC-CE from the base station to support the improved SRI and TPMI fields. The MAC-CE may contain information indicating changes to the interpretation of code points in the DCI fields, so as to indicate multiple transmission beams for a specific code point in the SRI field of the DCI, or to indicate multiple transmission precoders for a specific code point in the TPMI field.

[0556] The following two methods can be considered for indicating multiple transmission beams:

[0557] Receive a specific code point in the MAC-CE activated SRI field to indicate an SRS resource to which multiple SRS spatial relationship information is connected; and

[0558] The MAC-CE receives a specific code point in the SRI field to indicate multiple SRS resources to which an SRS spatial relationship information is connected.

[0559] When multiple SRS resources are indicated using the improved SRI field, transmit power control parameters for each SRS resource set are configured. Therefore, SRS resources can exist in different SRS resource sets to allow for different transmit power control parameters to be configured for each TRP. Consequently, there may be two or more SRS resource sets where the use of higher-layer signaling is configured as either codebook-based or non-codebook-based.

[0560] Figure 18 A flowchart illustrating the operation of a base station and a UE with respect to repeated PUSCH transmissions according to an embodiment of the present disclosure is shown, considering multiple TRPs based on a single DCI transmission using improved SRI and TPMI fields.

[0561] In Operation 1851, the UE can perform a UE capability report on whether PUSCH retransmission considering multiple TRPs based on a single DCI is supported, and a UE capability report on whether MAC-CE indicated by the SRI field or TPMI field for improvement is active.

[0562] In operation 1801, the base station receives the UE capability report.

[0563] In operation 1802, the base station sends a configuration to the UE that takes into account the repeated transmission of PUSCH based on multiple TRPs of a single DCI. Here, the transmitted configuration may include the repeated transmission method, the number of repeated transmissions, the transmission beam mapping unit or scheme, and multiple codebook or non-codebook SRS resource sets.

[0564] In operation 1852, the UE receives the configuration.

[0565] In Operation 1853, the UE receives a MAC-CE for activating the improved SRI field or TPMI field indication.

[0566] In Operation 1803, the UE sends a HARQ-ACK to the base station 3ms after receiving the signal. In other words, from the base station's perspective, the base station can receive the HARQ-ACK 3ms after the UE receives the MAC-CE indicating the activation of the improved SRI field or TPMI field.

[0567] In Operation 1804, the base station can determine whether the number of repeated transmissions exceeds 1.

[0568] In Operation 1854, the UE can determine whether the number of repeated transmissions exceeds 1.

[0569] In operations 1855 and 1856, when the PUSCH retransmission is a codebook-based PUSCH transmission and the successfully received DCI includes the improved SRI field and TPMI field, the UE can perform a first PUSCH transmission operation. The first PUSCH transmission operation is, in the case of codebook-based PUSCH transmission, repeatedly transmitting PUSCH using code points indicating multiple SRI and TPMI fields, and in the case of non-codebook-based PUSCH transmission, repeatedly transmitting PUSCH using code points indicating multiple SRI fields, and repeatedly transmitting PUSCH by applying multiple transmission beams and / or multiple transmission precoders. The method of mapping multiple transmission beams will be described in detail with reference to a second embodiment of this disclosure.

[0570] In Operation 1857, the second PUSCH transmission operation is the operation of repeatedly transmitting PUSCH when all code points in the SRI and TPMI fields receive a DCI indicating a single SRI and a single TPMI, and repeatedly transmitting PUSCH by applying a transmission beam and / or a transmission precoder.

[0571] Operations 1805, 1806, and 1807 are performed by the base station relative to the aforementioned operations 1855, 1856, and 1857.

[0572] <Second Embodiment: Frequency Hopping and Transmission Beam Mapping Method Considering Multiple TRPs During PUSCH Repetition Transmission>

[0573] In a second embodiment of this disclosure, a frequency hopping and transport beam mapping method for each PUSCH is described during repeated PUSCH transmissions considering multiple TRPs. Here, the transport beam can be an indicator relating to SRS resources, SRS spatial relationships, or collectively referred to as SRS spatial relationships and TPMI connected to SRS spatial relationship information. The frequency hopping method and the transport beam mapping method can be configured independently or relatedly via higher-layer signaling, can be indicated via L1 signaling, or can operate in combination with configuration via higher-layer signaling and indication via L1 signaling.

[0574] Independently executed frequency hopping methods and transmission beam mapping methods mean that these two methods are transmitted to the UE via independent signaling (e.g., via higher-layer signaling configuration, via L1 signaling indication, or a combination of higher-layer signaling configuration and L1 signaling indication). However, the number of all possible frequency hopping methods and the number of all possible transmission beam mapping methods may not all be composable. For example, when there are three frequency hopping methods and four transmission beam mapping methods, only 10 combinations may be supported instead of all 12 combinations. Detailed embodiments of this disclosure will be described below.

[0575] <Example (2-1): Transmission Beam Mapping Method Considering PUSCH Repetition Transmissions of Multiple TRPs>

[0576] In embodiment (2-1), a transmission beam mapping method considering multiple TRPs during PUSCH retransmission will be described. When the base station transmits multiple transmission beams via higher-layer signaling, via L1 signaling, or a combination of configuration via higher-layer signaling and indication via L1 signaling, the UE can consider multiple TRPs to determine how to perform the transmission beam mapping method during PUSCH retransmission. The information about the multiple transmission beams can be multiple SRIs to which SRS spatial relationship information is connected, or a single SRI to which SRS spatial relationship information is connected. The base station can transmit information about how to map which transmission beam to each PUSCH retransmission from multiple pieces of information about the multiple transmission beams received by the UE (i.e., the transmission beam mapping unit) from multiple pieces of information about the multiple transmission beams. Furthermore, the number of complete PUSCH retransmissions considering multiple TRPs during PUSCH retransmission can be configured via higher-layer signaling, indicated via L1 signaling, or transmitted via a combination of configuration via higher-layer signaling and indication via L1 signaling.

[0577] The following candidates can be used as transmission beam mapping units:

[0578] Each time slot or sub-time slot, or multiple time slots or sub-time slots;

[0579] Each repeated transmission (nominal or actual) or multiple repeated transmissions (nominal or actual);

[0580] Each symbol or multiple symbols; and / or

[0581] 1 / N of the total number of repeated transmissions.

[0582] When the transmit beam mapping unit is a time slot, the same transmit beam is applied to all PUSCH repetitions (nominal or actual) within the time slot, and the transmit beam changes on a time slot basis. For example, when the total number of PUSCH repetitions is 4, the number of transmit beams is 2, the transmit beam mapping unit is a time slot, and there are two PUSCH repetitions in each time slot, the first transmit beam can be applied to the first and second PUSCH repetitions transmitted from the first time slot, and the second transmit beam can be applied to the third and fourth PUSCH repetitions transmitted from the second time slot.

[0583] As another example, when the total number of repeat transmissions is 4, the number of transmission beams is 2, the transmission beam mapping unit is two time slots, and a PUSCH repeat transmission is performed once in each time slot, the first transmission beam can be applied to the first and second PUSCH repeat transmissions sent from the first and second time slots respectively, and the second transmission beam can be applied to the third and fourth PUSCH repeat transmissions sent from the third and fourth time slots respectively.

[0584] When the transmission beam mapping unit is 1 / N of the total number of PUSCH repetitions, N can be a divisor of the total number of repetitions or a natural number equal to or greater than 2 and less than or equal to the total number of repetitions. For example, when the number of PUSCH repetitions is 6, the number of transmission beams is 2, and the transmission beam mapping unit is 1 / 2 of the total number of repetitions (N=2), the UE can apply the first transmission beam to the first to third PUSCH repetitions and the second transmission beam to the fourth to sixth PUSCH repetitions.

[0585] Furthermore, regarding the fixed transmission beam mapping unit or transmission beam mapping unit that is configured by the UE to the base station via higher-layer signaling, indicated via L1 signaling, or received by the UE in a combination of configuration via higher-layer signaling and indication via L1 signaling, the base station may send one of the cyclic and sequential transmission beam mapping schemes to the UE via higher-layer signaling configuration, indication via L1 signaling, or a combination of configuration via higher-layer signaling configuration and indication via L1 signaling.

[0586] For example, when the total number of PUSCH retransmissions is 6, the number of transmission beams is 2, the transmission beam mapping unit is retransmitted (nominal or actual), and the transmission beam mapping scheme is cyclic, the UE can apply the first transmission beam to the odd-numbered PUSCH retransmission and the second transmission beam to the even-numbered PUSCH retransmission. When the transmission beam mapping scheme is sequential, the number of transmission beam mapping units used to apply the same transmission beam can be 2 or a divisor of the total number of retransmissions, and the corresponding information can be predetermined (e.g., fixed at 2, without specific signaling), configured via higher-layer signaling, indicated via L1 signaling, or a combination of configuration via higher-layer signaling and indication via L1 signaling.

[0587] In the example above, when the transmission beam mapping scheme is sequential and the number of transmission beam mapping units used to apply the same transmission beam is 2, the UE can apply the first transmission beam to the repeated transmission of the first and second PUSCHs, apply the second transmission beam to the repeated transmission of the third and fourth PUSCHs, and apply the first transmission beam to the repeated transmission of the fifth and sixth PUSCHs.

[0588] <Example (2-2): Independent Frequency Hopping and Transmission Beam Mapping Method>

[0589] In embodiment (2-2), a method for independently executing the frequency hopping method and the transmission beam mapping method during PUSCH repetition transmission considering multiple TRPs is described. Similar to the process of sending a transmission beam mapping unit from the base station to the UE, the frequency hopping method can be configured by the base station to the UE via higher-layer signaling, indicated via L1 signaling, or transmitted via a combination of higher-layer signaling configuration and L1 signaling indication. Furthermore, the UE can receive the frequency hopping method from the base station independently of the process of sending the transmission beam mapping unit.

[0590] The following candidates may be used as frequency hopping units:

[0591] Between or multiple time slots;

[0592] Frequency hopping methods in time slots;

[0593] Frequency hopping methods between internal repetitive transmissions or multiple repetitive transmissions; and / or

[0594] Frequency hopping method in repeated transmission.

[0595] The UE can independently apply frequency hopping methods and transmission beam mapping units, which are configured via higher-layer signaling, indicated via L1 signaling, or received via a combination of configuration via higher-layer signaling and indication via L1 signaling.

[0596] Figure 19A diagram is shown to illustrate a method for independently determining frequency hopping and transmission beam mapping during repeated PUSCH transmissions considering multiple TRPs, according to embodiments of the present disclosure.

[0597] For example, when the PUSCH repetition transmission is of type B, the total number of PUSCH repetitions (e.g., the nominal number of repetitions) is 5, the symbol length of the nominal repetition is 10, the frequency hopping method between nominal repetitions is used, the transmission beam mapping unit is a time slot, the number of PUSCH repetitions in the time slot is 1, the starting RB position is RB 0, and the RF offset caused by frequency hopping is 10 RBs, then the UE can apply the first transmission beam in the first and third time slots, and apply the second transmission beam in the second and fourth time slots. The UE transmits the first actual repetition 1901 from RB#0 in time slot #1, and the second actual repetition 1902 from RB#10 in time slot #1. The UE transmits the third actual repetition 1903 from RB#10 in time slot #2, and the fourth actual repetition 1904 from RB#0 in time slot #2. The UE transmits the fifth actual repeat 1905 from RB#0 in time slot #3, and the sixth actual repeat 1906 from RB#10 in time slot #3. The UE transmits the seventh actual repeat 1907 from RB#0 in time slot #4.

[0598] When a combination of a specific frequency hopping method and a transmission beam mapping unit is configured via higher-layer signaling, indicated via L1 signaling, or transmitted via a combination of configuration via higher-layer signaling and indication via L1 signaling, in addition to changing the transmission power according to the application of different transmission beams, the base station and UE may insert one or more symbol gaps or discard one or more transmission symbols between frequency hopping or repeated transmissions.

[0599] The base station and UE may not support a specific combination of frequency hopping methods and transmit beam mapping units. For example, when using this combination, it may not be supported if no frequency hopping occurs or only one transmit beam mapping occurs. For instance, if the total number of PUSCH repetitions is 2, the frequency hopping unit is a time slot, the transmit beam mapping unit is a PUSCH repetition, and the number of PUSCH repetitions in a time slot is 2, the UE can map the first transmit beam to the first PUSCH repetition in the first time slot, map the second transmit beam to the second PUSCH repetition, and not perform frequency hopping. The UE may not expect this combination to be configured by the base station via higher-layer signaling, indicated via L1 signaling, or transmitted in a combination of configuration via higher-layer signaling and indication via L1 signaling.

[0600] <Examples (2-3): Correlated frequency hopping and transmission beam mapping method>

[0601] In embodiments (2-3) of this disclosure, a method is described that independently executes a frequency hopping method and a transmission beam mapping method considering multiple TRPs during repeated PUSCH transmissions. The frequency hopping method and the transmission beam mapping method are determined independently to obtain as much frequency diversity and spatial diversity as possible relative to repeated PUSCH transmissions considering multiple TRPs. For example, the frequency hopping unit can be larger than the transmission beam mapping unit. In other words, the UE can transmit PUSCH from the same frequency location by applying different transmission beams to the PUSCH, and transmit PUSCH from another frequency location via frequency hopping by applying different transmission beams to the PUSCH. As another example, the frequency hopping unit can be smaller than the transmission beam mapping unit. In other words, the UE can transmit PUSCH from different frequency locations by applying the same transmission beam to the PUSCH, and transmit PUSCH from different frequency locations by applying different transmission beams to the PUSCH. As described above, the method for providing the dependency between the frequency hopping unit and the transmission beam mapping unit can consider the following three approaches.

[0602] [Method 1] Use independent configuration of frequency hopping and transmission beam mapping units.

[0603] The UE can perform the relevant frequency hopping and transmission beam mapping by using transmission schemes from the frequency hopping unit and the transmission beam mapping unit, respectively. The transmission schemes may be the same, but other limitations may exist.

[0604] For example, when the UE configures via higher-layer signaling, indicates via L1 signaling, or is configured and indicated by the base station using a combination of higher-layer and L1 signaling, frequency hopping method, and transport beam mapping method, the UE may expect the frequency hopping unit to be smaller than the transport beam mapping unit. For example, when the frequency hopping method is configured via higher-layer signaling, indicated via L1 signaling, or configured and indicated by a combination of higher-layer and L1 signaling on a time-slot basis, the UE does not expect a transport beam mapping unit larger than a time slot to be configured via higher-layer signaling, indicated via L1 signaling, or configured and indicated by a combination of higher-layer and L1 signaling.

[0605] As another example, when the UE configures via higher-layer signaling, indicates via L1 signaling, or is configured and indicated by the base station using a combination of higher-layer and L1 signaling, frequency hopping method, and transport beam mapping method, the UE can expect the frequency hopping unit to be larger than the transport beam mapping unit. For example, when the frequency hopping method is configured via higher-layer signaling, indicated via L1 signaling, or configured and indicated by a combination of higher-layer and L1 signaling on a time slot basis, the UE does not expect a transport beam mapping unit smaller than a time slot to be configured via higher-layer signaling, indicated via L1 signaling, or configured and indicated by a combination of higher-layer and L1 signaling.

[0606] [Method 2] Configure the transmission beam mapping unit based on the configuration of the frequency hopping unit.

[0607] The UE can support a transmission beam mapping unit based on a frequency hopping method configured by the base station via higher-layer signaling, indicated via L1 signaling, or a combination of higher-layer and L1 signaling. In other words, a transmission beam mapping unit can be configured and indicated to the UE in multiple configured or indicated frequency hopping units. For example, when the base station has already configured or indicated a frequency hopping method to the UE on a time slot basis, it can configure or indicate a transmission beam mapping unit to the UE through one or more time slots.

[0608] Figure 20 A schematic diagram is shown for describing the configuration of a transmission beam mapping unit based on the configuration of a frequency hopping unit according to an embodiment of the present disclosure.

[0609] When the number of PUSCH repetitions is 4, the frequency hopping method is based on time slots. The transmission beam mapping unit is configured or indicated as 2, so the transmission beam mapping is performed in units of 2 time slots. The number of PUSCH repetitions is 2 in one time slot. The starting RB position is the 0th RB, and the RB offset for frequency hopping is 10 RBs. The UE can transmit PUSCH 2001 by applying the first transmission beam from the 0th RB in the first time slot of the first PUSCH repetition, PUSCH 2002 by applying the first transmission beam from the 10th RB in the second time slot of the second PUSCH repetition, PUSCH 2003 by applying the second transmission beam from the 0th RB in the third time slot of the third PUSCH repetition, and PUSCH 2004 by applying the second transmission beam from the 10th RB in the fourth time slot of the fourth PUSCH repetition.

[0610] Furthermore, the transmission beam mapping unit can be configured or indicated to the UE in a smaller unit than the configured or indicated frequency hopping unit. The base station can use the following two methods to configure or indicate that the transmission beam mapping unit is smaller than the frequency hopping unit.

[0611] [Method 3] Define the available frequency hopping units as a set, and select the transmission beam mapping unit from the corresponding set.

[0612] The UE can predefine a set including available frequency hopping units. This set can be defined in the following order:

[0613] Unit 1. Within the actual PUSCH repetition transmission;

[0614] Unit 2. Actual PUSCH retransmission;

[0615] Unit 3. Within the nominal PUSCH repetitive transmission;

[0616] Unit 4. Nominal PUSCH repetitive transmission; and / or

[0617] Unit 5. Time Slot.

[0618] The UE can be configured by the base station via higher-layer signaling, indicated via L1 signaling, or configured and indicated via both higher-layer signaling and L1 signaling, to specify how much lower the transmission beam mapping unit is than the frequency hopping unit within the set. For example, when the UE is configured or indicated by the base station to use a frequency hopping method based on time slots (i.e., unit 5), and is configured and indicated to use a transmission beam mapping unit one unit lower than the frequency hopping unit, the UE can perform transmission beam mapping based on nominal PUSCH repetition transmissions (i.e., unit 4).

[0619] Furthermore, during PUSCH repetitions across multiple TRPs, when the transmission beam mapping unit or transmission beam mapping scheme and frequency hopping method are transmitted via higher-layer signaling, indicated via L1 signaling, or a combination of higher-layer signaling configuration and L1 signaling indication, the UE can ignore the frequency hopping method to reduce the UE's burden. Additionally, when the transmission beam mapping unit or transmission beam mapping scheme and frequency hopping method are transmitted via higher-layer signaling, indicated via L1 signaling, or a combination of higher-layer signaling configuration and L1 signaling indication, the UE does not expect both the transmission beam mapping unit and the frequency hopping unit to be applied to the time slot (e.g., when the transmission beam mapping unit is actually repeated and the frequency hopping unit is a repetition within the time slot).

[0620] <Third Embodiment: PTRS-DMRS Association Method Considering Multiple TRPs>

[0621] In a third embodiment of this disclosure, a PTRS-DMRS association method is described for determining the port of the PTRS to be transmitted with the PUSCH for each TRP during repeated PUSCH transmissions considering multiple TRPs, and a method for transmitting the PTRS based on the PTRS-DMRS association method is described. The PTRS-DMRS association method can be divided into a method for determining the port of the PTRS and transmitting the PTRS for multiple TRPs via different PTRS-DMRS associations, and a method for determining the port of the PTRS and transmitting the PTRS for all TRPs via the same PTRS-DMRS association, as described in embodiments (3-1) and (3-2) of this disclosure.

[0622] <Example (3-1): Method for determining the PTRS port and sending PTRS data for multiple TRPs via different PTRS-DMRS associations>

[0623] In embodiment (3-1), a method is described in which a base station indicates to a UE the PTRS-DMRS association for each of multiple TRPs, and the UE transmits PTRS based on the PTRS-DMRS association. In NR Release 15 / 16, the association between the PTRS port and DMRS port for a single TRP is indicated by a PTRS-DMRS association field in the DCI used for scheduling PUSCH. However, a method is needed to indicate the association between the PTRS port and DMRS port for each TRP with respect to PUSCH repeatedly transmitted by multiple TRPs. When PUSCH is repeatedly transmitted by N TRPs and phase is tracked and phase errors are compensated for by PTRS, the base station can indicate N PTRS-DMRS associations to the UE. In the following, for convenience, embodiments of this disclosure are described as N being 2, but the provided techniques can be extended and applied to support a number greater than 2 TRPs.

[0624] Considering multiple TRPs, the method for indicating PTRS-DMRS association for each TRP may include the following detailed operations:

[0625] Methods for adding PTRS-DMRS related fields in DCI;

[0626] A method based on a PTRS-DMRS association table, defining a PTRS-DMRS association table that can be newly configured for multiple TRPs, and indicating PTRS-DMRS association for multiple TRPs; and / or

[0627] A method for reinterpreting PTRS-DMRS association fields, taking into account multiple TRPs.

[0628] The detailed operations are described in the detailed embodiments (3-1-1), (3-1-2), and (3-1-3) of this disclosure.

[0629] <Detailed Example (3-1-1): Method for Adding PTRS-DMRS Association Fields to DCI>

[0630] In the current detailed embodiment of this disclosure, a method for adding a PTRS-DMRS association field to the DCI based on the number of TRPs that the UE can support is described by extending the operation of setting only one PTRS-DMRS association field in the DCI. The method for adding a PTRS-DMRS association field considering multiple TRPs is described in detail below through the operation between the UE and the base station. The UE can perform a UE capability report, notifying the base station that multiple TRPs are supported. The base station can determine the number of TRPs to be supported based on the UE capability reported by the UE, and configure RRC parameters for the UE based on the number of TRPs. Here, in order to determine the bit size of the PTRS-DMRS association field in the DCI, in addition to identifying the configuration values ​​of maxRank in the transform precoding, the higher-layer parameter PTRS-UplinkConfig (PTRS-Uplink Configuration), and the higher-layer parameter PUSCH-Config, the higher-layer parameter configuration used to send PUSCH to multiple TRPs or the field used to indicate multiple TRP transmissions in the same DCI can also be identified.

[0631] The UE determines that the PUSCH can be sent by multiple TRPs with respect to one or a combination of the following candidates:

[0632] - Candidate 1) When a higher-layer parameter (e.g., “enablePUSCHwithTwoSRSSet”) is configured to support PUSCH retransmission, multiple TRPs, such as “enable” or “on”, are considered based on the UE capabilities reported by the UE.

[0633] - Candidate 2) When the number of SRS resource sets in which “Use” is configured as “Codebook” or “Non-Codebook” is 2;

[0634] - Candidate 3) When the SRI and / or TPMI fields in the DCI used for scheduling PUSCH indicate two SRIs and / or two TPMIs (this can include two cases where there are two SRI fields and / or two TPMI fields, and where a single field is reinterpreted as indicating two values ​​for each field); and / or

[0635] - Candidate 4) When considering multiple TRP PUSCH retransmissions received by DCI from CORESET configured by two different CORESETPoolIndex (CORESET pool index).

[0636] Thus, when the UE identifies the configuration for repeated PUSCH transmissions based on multiple TRPs, the UE can verify that the same number of PTRS-DMRS association fields are configured as in DCI format 0_1 ​​or 0_2 for the multiple TRPs. When PUSCH is repeatedly transmitted through two TRPs, the number of PTRS-DMRS association fields in DCI format 0_1 ​​or 0_2 is two. Multiple PTRS-DMRS association fields are used to determine the port of the PTRS sent to each TRP. When the number of PTRS-DMRS association fields is two, the UE can use the first PTRS-DMRS association field to determine the PTRS for the TRP indicated by the first SRI and / or TPMI, and use the second PTRS-DMRS association field to determine the PTRS for the TRP indicated by the second SRI and / or TPMI.

[0637] Depending on the number of SRIs and TPMIs indicated by the SRI and TPMI fields in the DCI, the UE can send PUSCH considering a single TRP or multiple TRPs via method candidate 3. When the SRI and TPMI fields in the DCI indicate one SRI and one TPMI, the UE can send PUSCH through a single TRP and determine that only one PTRS-DMRS association field is configured. On the other hand, when the SRI and TPMI fields in the DCI indicate two SRIs and two TPMIs, the UE can send PUSCH through multiple TRPs and determine that two PTRS-DMRS association fields are configured. When the base station has configured higher-layer parameters for supporting repeated PUSCH transmissions considering multiple TRPs for the UE via method candidate 1 or candidate 4, but the scheduled PUSCH is supported by a single TRP, the number of PTRS-DMRS association fields in the DCI can be configured to two, but only one PTRS-DMRS association field can be applied by the UE to the actual PTRS transmission. In this case, the UE can ignore the added PTRS-DMRS association field and determine the association between the PTRS port and the DMRS port by using the two MSB bits corresponding to the first PTRS-DMRS association field.

[0638] <Detailed Implementation Example (3-1-2): PTRS-DMRS Association Method Based on Reconfigurable PTRS-DMRS Association Tables Considering Multiple TRPs>

[0639] The base station and UE can determine the association between PTRS ports and DMRS ports by referring to the PTRS-DMRS association field and Table 19-1 or 19-2, based on the maximum number of PTRS ports configured by higher layers. In the detailed embodiment (3-1-2) of this disclosure, a method for determining the association between PTRS ports and DMRS ports is described by using a new configurable table instead of the table used for fixed PTRS-DMRS associations, such as Table 19-1 or 19-2. The base station can configure candidates for the association between PTRS and DMRS for two TRPs by using uplink channel information of each TRP estimated by receiving SRS, or uplink channel information of each TRP estimated by channel reciprocity based on CSI report information reported by the UE. Since each TRP shows four associations between PTRS and DMRS, the association between PTRS and DMRS can be represented by a total of 16 combinations considering two TRPs.

[0640] However, when the base station includes uplink channel information, the base station can notify the UE of some of the 16 frequently indicated associations in total, and can perform PTRS-DMRS associations with respect to two TRPs based on some of these associations. Referring to an example of a detailed embodiment according to (3-1-2) of this disclosure, specifically, when the number of PTRS ports is 1, the base station can configure a new PTRS-DMRS association table based on the channel information between the UE and each TRP, as shown in Table 21 below.

[0641] [Table 21]

[0642] value DMRS port 0 The first DMRS, the first DMRS 1 DMRS of the second schedule, DMRS of the second schedule 2 DMRS of the 3rd schedule, DMRS of the 1st schedule 3 DMRS of the 3rd schedule, DMRS of the 4th schedule

[0643] In Table 21, information about the two scheduled DMRSs is included in the DMRS port field. The first scheduled DMRS indicated in the DMRS port field of Table 21 indicates PTRS-DMRS association information for TRP 1, while the second scheduled DMRS indicates PTRS-DMRS association information for TRP 2. When the bit value of the PTRS-DMRS association field indicated by the DCI is 1, the UE associates the PTRS port for TRP 1 with the second scheduled DMRS port for TRP 1, and associates the PTRS port for TRP 2 with the second scheduled DMRS port for TRP 2. Here, the second scheduled DMRS port for TRP 1 and the second scheduled DMRS port for TRP 2 represent different channel layers and therefore do not represent the same DMRS port.

[0644] Table 21 is an example, and the number of DMRS port fields or value fields in the table can be determined differently based on the maximum number of PTRS ports and the channel state between the UE and each TRP. The base station determines the PTRS-DMRS association table by determining the number of DMRS port fields and value fields based on the maximum number of PTRS ports and the channel state between the UE and each TRP. The base station can then configure or update the determined PTRS-DMRS association table to the UE using new RRC parameters or MAC CE.

[0645] <Detailed Implementation Example (3-1-3): A Method for Reinterpreting the PTRS-DMRS Association Field Considering Multiple TRPs>

[0646] In the detailed embodiment (3-1-3) of this disclosure, a method is provided to determine the PTRS for each TRP by reinterpreting the PTRS-DMRS association field when the PUSCH is transmitted by multiple TRPs. As described with reference to the method according to the detailed embodiment (3-1-1) of this disclosure, the UE can determine whether the PUSCH is repeatedly transmitted by multiple TRPs. When the PUSCH is repeatedly transmitted by multiple TRPs, the UE reinterprets the two bits of the PTRS-DMRS association field indicated by DCI format 0_1 ​​or 0_2 and determines the association between the PTRS port and DMRS port for each TRP.

[0647] Here, of these two bits, one MSB can be used to indicate the PTRS-DMRS association for TRP 1 (or the TRP associated with the first SRI of the two SRIs), and one LSB can be used to indicate the PTRS-DMRS association for TRP 2 (or the TRP associated with the second SRI of the two SRIs). The UE can determine the PTRS information for each TRP by combining one bit of the PTRS-DMRS association field for each TRP indicated by the DCI and SRI in the same DCI (during non-codebook-based PUSCH transmission) or TPMI (during codebook-based PUSCH transmission). Detailed operation of the present detailed embodiment of this disclosure will be described by the following examples.

[0648] In one example, [Case 1] with a maximum of two PTRS ports, Layer 2 non-codebook PUSCH retransmission considers multiple TRPs, and the base station instructs two SRIs to indicate the SRS resources selected for each TRP, where each SRI indicates two SRS resources. As mentioned above, in non-codebook SRS, the PTRS port index associated with the SRS resources in the higher-layer SRS-Resource is configured by ptrs-PortIndex. In other words, in the SRS resources in the non-coded SRS resource set, the associated PTRS port index is configured by higher-layer parameters, and the UE can determine the selected SRS resource by the SRI in the DCI and the PTRS port index of the selected SRS resource. When the number of SRS resources in the SRS resource set is 4, in Case 1, the combinations of PTRS port indices of the two SRS resources selected by the SRI are {0,0}, {0,1}, {1,0}, and {1,1}. Then, SRS resources are mapped to PUSCH DMRS ports in a one-to-one manner, thus the association between PTRS ports and DMRS ports becomes the same as the association between SRS resources and PTRS ports. Here, when two DMRS ports are associated with the same PTRS port, such as the combination of PTRS port indices for the SRS resource selected by the SRI being {0,0} and {1,1}, the association of a PTRS port with a DMRS port can be indicated by using the PTRS-DMRS association field. When two DMRS ports are associated with different PTRS ports, such as the combination of PTRS port indices for the SRS resource selected by the SRI being {0,1} and {1,0}, the association between DMRS and PTRS can be determined without the individual bits of the PTRS-DMRS association field. By using such a relationship, the association between a PTRS port and a DMRS port with respect to a TRP can be determined by 1 bit of case 1 and the SRI. Therefore, one MSB of the PTRS-DMRS association field can be applied to determine the PTRS of TRP 1 (or the TRP associated with the first SRI of the two SRIs), and one LSB can be applied to determine the PTRS of TRP 2 (or the TRP associated with the second SRI of the two SRIs).

[0649] Figure 21 An example diagram is shown to illustrate a method for determining the PTRS-DMRS association field that takes into account multiple TRPs by reinterpreting the PTRS-DMRS association field with respect to case 1.

[0650] The UE sends a non-codebook SRS resource set 2100 for TRP 1 to the base station. SRS resource set 2100 includes SRS resource 2105 associated with PTRS port 0 and SRS resource 2110 associated with PTRS port 1. In operation 2120, the base station indicates an SRI to the UE via DCI to select two SRS resources from the four SRS resources for TRP 1. The two selected SRS resources are mapped to DMRS in a one-to-one manner to configure DMRS ports (operation 2130). Here, both DMRS ports are associated with PTRS port 0, and in operation 2140, a PTRS-DMRS association field is required to select a first DMRS port from the two DMRS ports.

[0651] In NR Release 15 / 16, to indicate the PTRS-DMRS association field, for example, the base station can configure the PTRS-DMRS association field by setting two bits of the PTRS-DMRS association field to 00, where the LSB can be ignored. In the provided method, it is supported to determine the PTRS port for TRP 1 using only one bit, reducing the number of ignored bits. Therefore, the base station configures the MSB of the PTRS-DMRS association field for TRP 1 to 0 and indicates the same information to the UE. The UE receives the same information and determines the PTRS-DMRS association for TRP 1. The UE sends a non-codebook SRS resource set 2150 for TRP 2 to the base station, where SRS resource set 2150 includes SRS resource 2155 associated with PTRS port 0 and SRS resource 2160 associated with PTRS port 1. In operation 2170, the UE is instructed via DCI to select two SRS resources from the four SRS resources for TRP 2. The two selected SRS resources are mapped to DMRS in a one-to-one manner to configure the DMRS port (operations 2180 and 2185). Here, because the two DMRS ports are associated with PTRS port 0 and PTRS port 1 respectively, the UE can associate PTRS and DMRS in operations 2190 and 2195 without the need for a separate PTRS-DMRS association.

[0652] Therefore, the base station can configure the LSB of the PTRS-DMRS association field in TRP 2 to x. Here, x can be configured by any bit and can be configured to 0, as predefined between the base station and the UE (or it can be configured to 1). The UE can associate the PTRS port and the DMRS port by referring to the received SRI about TRP 2. Figure 21 This is just an example of Case 1. Depending on the method of configuring the PTRS port of the SRS resource, the number of SRS resources, and the indicated SRI, Case 1 can be applied differently.

[0653] In one example, [Case 2] with a maximum of two PTRS ports, the Layer 3 non-codebook PUSCH retransmission considers multiple TRPs. Similar to Case 2, two SRIs are indicated to indicate the SRS resources selected for each TRP, where each SRI indicates three SRS resources. When the number of SRS resources in the SRS resource set is 4, in Case 2, the combinations of PTRS port indices for the three SRS resources selected via SRIs are {1, 0, 0}, {0, 1, 0}, {0, 0, 1}, {0, 1, 1}, {1, 0, 1, 1}, and {1, 1, 0}. Here, when the number of selected SRS resources associated with PTRS port 0 or 1 is 1, the DMRS associated with the PTRS port can be determined without the need for a separate bit for PTRS-DMRS association. In other words, when the combination of PTRS port indices for the SRS resource selected via SRI is {1, 0, 0}, {0, 1, 0}, and {0, 0, 1}, PTRS port 1 and the corresponding DMRS port can be associated without a separate bit regarding the PTRS-DMRS association for PTRS port 1, and the associated DMRS port can be determined by indicating the PTRS-DMRS association with 1 bit regarding PTRS port 0. When the combination of PTRS port indices for the SRS resource selected via SRI is {0, 1, 1}, {1, 0, 1}, and {1, 1, 0}, PTRS port 0 and the corresponding DMRS port can be associated without a separate bit regarding the PTRS-DMRS association for PTRS port 0, and the associated DMRS port can be determined by indicating the PTRS-DMRS association with 1 bit regarding PTRS port 1. By using such a relationship, the association between the PTRS port and DMRS port for a TRP can be determined by 1 bit from case 2 and the SRI. Therefore, one MSB of the PTRS-DMRS association field can be applied to determine the PTRS of TRP 1 (or the TRP associated with the first SRI of the two SRIs), and one LSB can be applied to determine the PTRS of TRP 2 (or the TRP associated with the second SRI of the two SRIs).

[0654] Figure 22An example of a method for determining the PTRS-DMRS association field by reinterpreting the PTRS-DMRS association field with respect to case 2, considering multiple TRPs, is shown. The UE sends a non-codebook SRS resource set 2200 for TRP 1 to the base station. SRS resource set 2200 includes SRS resource 2205 associated with PTRS port 0 and SRS resource 2210 associated with PTRS port 1. In operation 2220, the base station instructs the UE via DCI to select three SRS resources from the four SRS resources for TRP 1. The three selected SRS resources are mapped to DMRS in a one-to-one manner to configure the DMRS port (operations 2230 and 2235).

[0655] In operations 2240 and 2245, the base station can determine the DMRS ports associated with PTRS ports 0 and 1. Here, since the number of DMRS ports associated with PTRS port 1 is 1, PTRS and DMRS can be associated without a separate PTRS-DMRS association (operation 2245). In operation 2240, when the first DMRS port of the two DMRS ports associated with PTRS port 0 is determined to be associated, the base station sets the 1MSB of the PTRS-DMRS association field used to determine the PTRS of TRP1 to 0. The UE sends a non-codebook SRS resource set 2250 for TRP 2 to the base station. SRS resource set 2250 includes SRS resource 2255 associated with PTRS port 0 and SRS resource 2260 associated with PTRS port 1. In operation 2270, the base station instructs the UE via DCI to select three SRS resources from the four SRS resources for TRP 1. The three selected SRS resources are mapped to DMRS in a one-to-one manner to configure DMRS ports (operations 2280 and 2285).

[0656] In operations 2290 and 2295, the base station can determine the DMRS ports associated with PTRS ports 0 and 1. Here, because the number of DMRS ports associated with PTRS port 0 is 1, PTRS and DMRS can be associated without a separate PTRS-DMRS association (operation 2290). In operation 2295, when the second DMRS port among the two DMRS ports associated with PTRS port 1 is determined to be associated, the base station sets the 1LSB of the PTRS-DMRS association field used to determine the PTRS of TRP 2 to 1. Figure 22 This is just an example of case 2. Depending on the method of configuring the PTRS port of the SRS resource, the number of SRS resources, and the indicated SRI, case 2 can be applied differently.

[0657] In one example, [Case 3] involves a maximum of two PTRS ports, considering repeated transmission of Layer 2 codebook PUSCH for multiple TPRs: In Case 3, the base station indicates the SRS resources and two-layer precoders for each TRP to the UE via two SRIs and two TPMIs. As described above, when PUSCH is transmitted based on the codebook, the PTRS port associated with the corresponding layer is defined according to the antenna port index of the PUSCH transmitted for that layer.

[0658] For example, when PUSCH is transmitted based on a partially coherent codebook and layer 1 is transmitted through PUSCH antenna ports 1000 and 1002, layer 1 is associated with PTRS port 0. When layer 2 is transmitted by PUSCH antenna ports 1001 and 1003, layer 2 is associated with PTRS port 1. Thus, the PUSCH antenna ports through which the layers are transmitted can be indicated to the UE via TPMI, allowing the UE to identify the PTRS port associated with each layer.

[0659] When transmitting Layer 2 partially coherent or incoherent codebook PUSCH using four PUSCH antenna ports, based on the NR version 15 / 16 precoding matrix, the combination of the indicated TPMI and the PTRS port index associated with each layer can be {0, 1}, {0, 0}, {1, 0}, and {1, 1}. Similar to the method for determining the Layer 2 PTRS port for case 1, when two DMRS ports are associated with the same PTRS port, such as when the combination of the indicated TPMI and the PTRS port index associated with each layer is {0, 0} and {1, 1}, the PTRS port can be indicated to be associated with a DMRS port by using the PTRS-DMRS association field.

[0660] When two DMRS ports are associated with different PTRS ports, such as when the combination of the PTRS port indices associated with each layer via the indicated TPMI is {0, 1} and {1, 0}, the association between the DMRS and PTRS can be determined without a single bit of the PTRS-DMRS association field. Using such a relationship, for case 3, the association between the PTRS and DMRS ports for a TRP can be determined by 1 bit and the TPMI. Therefore, 1 MSB of the PTRS-DMRS association field can be applied to determine the PTRS of TRP 1 (or the TRP associated with the first SRI of the two SRIs), and 1 LSB can be applied to determine the PTRS of TRP 2 (or the TRP associated with the second SRI of the two SRIs).

[0661] Figure 23A diagram is shown to illustrate a method for determining the PTRS-DMRS association field by considering multiple TRPs through reinterpreting the PTRS-DMRS association field with respect to case 3.

[0662] The base station indicates to the UE the TPMI determined by the DCI based on the received SRS to schedule codebook-based PUSCH repetition transmissions for TRP 1 (operation 2300). The indicated TPMI indicates the precoding matrix for layer 2 PUSCH transmissions, and according to the example of operation 2300, the DMRS port corresponding to layer 1 is associated with PTRS port 0 because the DMRS port is transmitted by PUSCH antenna ports 1000 and 1002 (operation 2310), and the DMRS port corresponding to layer 2 is associated with PTRS port 1 because the DMRS port is transmitted by PUSCH antenna ports 1001 and 1003 (operation 2315). Because the two DMRS ports are associated with different PTRS ports, PTRS and DMRS can be associated without a separate PTRS-DMRS association (operations 2320 and 2325).

[0663] Therefore, the base station can configure one MSB of the PTRS-DMRS association field of TRP 1 as x. Here, x can be configured by any bit and can be configured as 0, as predefined between the base station and the UE (or it can be configured as 1). The base station indicates to the UE the TPMI determined by the DCI based on the received SRS to schedule codebook-based PUSCH repetition transmissions with respect to TRP 2 (operation 2330). The indicated TPMI indicates the precoding matrix for layer 2 PUSCH transmissions, and according to the example of operation 2330, the DMRS port corresponding to the first layer is associated with PTRS port 0 because the DMRS port is transmitted by PUSCH antenna port 1000 (operation 2340), and the DMRS port corresponding to the second layer is associated with PTRS port 0 because the DMRS port is transmitted by PUSCH antenna port 1002 (operation 2345).

[0664] Because two DMRS ports are associated with the same PTRS port, a bit is needed to indicate that one of the DMRS ports is associated with the PTRS port. For example, in operation 2350, when the base station associates a PTRS port with a second DMRS port from the DMRS ports associated with PTRS port 0, the base station can configure one LSB of the PTRS-DMRS association field of TRP 2 to 1. Figure 23 This is just an example of case 3, and case 3 can be applied differently depending on the number of SRS resource ports, the indicated TPMI, etc.

[0665] In one example, [Case 4] with a maximum of two PTRS ports, Layer 3 codebook PUSCH retransmission considers multiple TPRs. Similar to Case 3, the base station indicates the SRS resources and Layer 3 precoder for each TPR to the UE via two SRIs and two TPMs. When transmitting Layer 3 partially coherent or incoherent codebook PUSCH using four PUSCH antenna ports, based on the NR version 15 / 16 precoding matrix, the combination of PTRS port indices associated with each layer can be {0, 1, 0} and {0, 1, 1} according to the indicated TPMI. When the combination of PTRS port indices associated with each layer via the indicated TPMI is {0, 1, 0}, the DMRS port corresponding to PTRS port 1 is associated without a separate bit regarding the PTRS-DMRS association of PTRS port 1, and the associated DMRS port can be determined by indicating the PTRS-DMRS association with PTRS port 0 using 1 bit. When the combination of the PTRS port index associated with each layer via the indicated TPMI is {0, 1, 1}, the DMRS port corresponding to PTRS port 0 is associated without a separate bit for the PTRS-DMRS association with PTRS port 0, and the associated DMRS port can be determined by indicating the PTRS-DMRS association with 1 bit for PTRS port 1. Using this relationship, for case 4, the association between the PTRS port and DMRS port for a TRP can be determined by 1 bit and the TPMI. Therefore, 1 MSB of the PTRS-DMRS association field can be applied to determine the PTRS of TRP 1 (or the TRP associated with the first SRI of the two SRIs), and 1 LSB can be applied to determine the PTRS of TRP 2 (or the TRP associated with the second SRI of the two SRIs).

[0666] Figure 24An example of a method for determining the PTRS-DMRS association field by reinterpreting the PTRS-DMRS association field with respect to case 4, considering multiple TRPs, is shown. The base station indicates to the UE the TPMI determined by the DCI based on the received SRS to schedule codebook-based PUSCH repetition transmissions with respect to TRP 1 (operation 2400). The indicated TPMI indicates the precoding matrix for layer 3 PUSCH transmissions, and according to the example of operation 2400, the DMRS port corresponding to the first layer is associated with PTRS port 0 because the DMRS port is transmitted by PUSCH antenna ports 1000 and 1002 (operation 2410), the DMRS port corresponding to the second layer is associated with PTRS port 1 because the DMRS port is transmitted by PUSCH antenna port 1001 (operation 2415), and the DMRS port corresponding to the third layer is associated with PTRS port 1 because the DMRS port is transmitted by PUSCH antenna port 1003 (operation 2415).

[0667] Because the number of DMRS ports associated with PTRS port 0 is 1 for TRP 1, PTRS and DMRS can be associated without a separate PTRS-DMRS association (Operation 2420). Because two DMRS ports are associated with PTRS port 1 for TRP 1, bits are needed to indicate that one of the DMRS ports is associated with the PTRS port. As in Operation 2425, when the base station associates a PTRS port with the first DMRS port from those associated with PTRS port 1, the base station can configure one MSB of the PTRS-DMRS association field of TRP 1 to 0. The base station indicates to the UE the TPMI determined by the DCI based on the received SRS to schedule codebook-based PUSCH retransmissions for TRP 2 (Operation 2430).

[0668] The indicated TPMI indicates the precoding matrix used for layer 3 PUSCH transmission, and according to the example of operation 2430, the DMRS port corresponding to the first layer is associated with PTRS port 0 because the DMRS port is transmitted by PUSCH antenna ports 1000 and 1002 (operation 2440), the DMRS port corresponding to the second layer is associated with PTRS port 1 because the DMRS port is transmitted by PUSCH antenna port 1001 (operation 2445), and the DMRS port corresponding to the third layer is associated with PTRS port 1 because the DMRS port is transmitted by PUSCH antenna port 1003 (operation 2445). Because the number of DMRS ports associated with PTRS port 0 is 1 for TRP 1, PTRS and DMRS can be associated without a separate PTRS-DMRS association (operation 2450).

[0669] Because two DMRS ports are associated with PTRS port 1 for TRP 1, a bit is needed to indicate that one of the DMRS ports is associated with the PTRS port. For example, in operation 2455, when the base station associates a PTRS port with a second DMRS port from the DMRS ports associated with PTRS port 1, the base station can configure one LSB of the PTRS-DMRS association field of TRP 2 to 1. Figure 24 This is merely an example of case 4, and case 4 can be applied differently depending on the indicated TPMI, etc.

[0670] In one example, [Case 5] with a maximum of one PTRS port, Layer 2 non-codebook or codebook PUSCH retransmissions, considering multiple TPRs, when the number of PTRS ports is 1 and Layer 2 PUSCH transmissions are performed, the DMRS associated with PTRS port 0 in the two layers indicated by the SRI (non-codebook-based PUSCH transmission) or TPMI (codebook-based PUSCH transmission) can be determined by 1 bit. Therefore, 1 MSB of the PTRS-DMRS association field can be applied to determine the PTRS of TRP 1 (or the TRP associated with the first SRI of the two SRIs), and 1 LSB can be applied to determine the PTRS of TRP 2 (or the TRP associated with the second SRI of the two SRIs).

[0671] Regarding cases 1 to 5 above, the association between the PTRS and DMRS ports with respect to the two TRPs can be determined by considering a reinterpretation of SRI or TPMI without adding bits to the PTRS-DMRS association field in the DCI. However, the above method cannot be applied when the maximum number of PTRS ports is 2 and the layer is 4, and when the maximum number of PTRS ports is 1 and the layer is 3 or 4.

[0672] When this method cannot be applied, the association between the PTRS port and the DMRS port can be determined by selecting one of the following options:

[0673] Option 1: When the maximum number of ports is 1, the maximum number of candidates that can be associated with a DMRS port can be limited from 4 to 2; and / or

[0674] Option 2: When the maximum number of ports is 2, determine an association for each TRP with respect to one PTRS port, and this association can be applied in the same way to determine two PTRS ports. For example, the association for PTRS port 0 of TRP 1 can be determined as 1 bit, and this association can be applied in the same way to PTRS port 1 of TRP 1; the association for PTRS port 0 of TRP 2 can be determined as 1 bit, and this association can be applied in the same way to PTRS port 1 of TRP 2.

[0675] Multiple TRPs can be considered for repeated PUSCH transmissions to improve PUSCH reliability. Here, when PUSCH is repeatedly transmitted over multiple TRPs, the number of layers per TRP may be limited. In NR versions 15 / 16, PUSCH can be transmitted at a maximum of 4 layers, but when PUSCH is repeatedly transmitted by multiple TRPs, the number of layers per TRP can be limited to a value less than 4. When the maximum number of PTRS ports is 2 and the number of TRP layers used for repeated PUSCH transmissions by multiple TRPs is limited to 2, the association between PTRS ports and DMRS ports can be determined as case 1 or 3 above.

[0676] Alternatively, because the number of layers is limited to 2, the base station and UE can predefine the association between PTRS ports and DMRS ports, such that PTRS port 0 is associated with the first DMRS port among the indicated DMRS ports, and PTRS port 1 is associated with the second DMRS port among the indicated DMRS ports, without any separate PTRS-DMRS association. When the maximum number of PTRS ports is 2 and the number of TRP layers for PUSCH retransmissions sent by multiple TRPs is limited to 3, the association between PTRS ports and DMRS ports can be determined as case 2 or 4 above.

[0677] When a base station indicates the PTRS-DMRS association for one TRP by reinterpreting the PTRS-DMRS association field, it can implicitly support inferring the PTRS-DMRS association for another TRP. The base station and UE can obtain statistical information by estimating the uplink channel between each TRP and the UE. When the base station and UE contain the same uplink channel statistics, and the PTRS-DMRS association field for TRP 1 is indicated by the DCI, the UE can statistically determine the PTRS-DMRS association information for TRP 2. The above operations will be described in detail with specific examples.

[0678] When the maximum number of PTRS ports is 1, DMRS port 2 for TRP 1, scheduled by PTRS-DMRS association, can be selected to be associated with a PTRS port. When DMRS port 2 scheduled for TRP 1 is associated with a PTRS port, statistically, the probability of selecting DMRS port 1 scheduled for TRP 2 is high. Here, the base station indicates the association between the PTRS port and DMRS port to be determined for TRP 1 via the PTRS-DMRS association field. The UE can determine that the DMRS port associated with the PTRS port for TRP 2 is 1 based on statistical characteristics and the association between the PTRS port and DMRS port for TRP 1 determined by the indicated PTRS-DMRS association. Because the base station contains the same statistical information, the base station knows the association between the PTRS port and DMRS port for TRP 2 determined by the UE.

[0679] <Embodiment (3-2) of this disclosure: A method for determining the PTRS port and sending PTRS via the same PTRS-DMRS association of all TRPs>

[0680] In embodiments (3-2) of this disclosure, a method is described in which a base station indicates the same PTRS-DMRS association for all TRPs to a UE, and the UE transmits PTRS based on the PTRS-DMRS association. Considering multiple TRPs, the base station can determine a PTRS-DMRS association field. Here, the base station can determine the PTRS-DMRS association field by selecting one of the following methods.

[0681] In one embodiment of method 1, the channel gains for the i-th layer (i = 1, 2, 3, and 4) of the two TRPs are summed. Then, the sum of the channel gains for each layer is compared to determine the PTRS-DMRS association field, such that the PTRS is associated with the layer with the highest sum of channel gains, and the PTRS-DMRS association field can be indicated to the UE.

[0682] In one embodiment of method 2, the base station may select one TRP from two TRPs, determine the PTRS-DMRS association field for the selected TRP, and indicate the PTRS-DMRS association field to the UE. (When selecting a TRP, the base station may choose a TRP with a high average channel gain. Alternatively, the base station may choose a TRP with a low average channel gain. Or, the base station may randomly select a TRP.)

[0683] The UE can identify and apply a PTRS-DMRS association field indicated by the base station via DCI to determine the association between the PTRS port and the DMRS port regarding two TRPs.

[0684] Figure 25 A flowchart illustrating the configuration of the PTRS-DMRS association field considering repeated PUSCH transmissions of multiple TRPs according to embodiments of the present disclosure, and the operation of performing PTRS-DMRS association, is shown.

[0685] In Operation 2551, the UE can perform a UE capability report regarding whether PUSCH retransmission based on multiple TRPs using a single DCI is supported.

[0686] In operation 1501, the base station receives the UE capability report.

[0687] In operation 2502, the base station sends a configuration to the UE that takes into account the repeated transmission of PUSCH based on multiple TRPs using a single DCI. This configuration may include the repeated transmission method, the number of repeated transmissions, the transmission beam mapping unit or scheme, whether the SRI or TPMI fields of multiple TRPs are supported, and multiple codebook or non-codebook SRS resource sets.

[0688] In operations 2552 and 2553, the UE receives the configuration and determines whether the number of repeated transmissions is equal to or greater than 2.

[0689] In operation 2554, when the number of repeated transmissions is equal to or greater than 2, the UE determines whether to perform a repeated PUSCH transmission based on the higher-layer configuration and the DCI that has been successfully received, taking into account multiple TRPs.

[0690] In operation 2555, when multiple TRPs determine that a PUSCH retransmission should be performed, the UE performs a first PTRS-DMRS association operation. Otherwise, in operation 2556, the UE performs a second PUSCH transmission operation. The first PTRS-DMRS association operation represents the operation of determining an association between PTRS and DMRS to transmit PTRS through multiple TRPs, as described in the third embodiment of this disclosure. The second PTRS-DMRS association operation represents the operation of determining an association between PTRS and DMRS to transmit PTRS through a single TRP, as described in NR version 15 / 16.

[0691] Operations 2503, 2504, 2505, and 2506 are performed by the base station relative to operations 2553, 2554, 2555, and 2556.

[0692] Figure 26 This is a structural diagram of a UE 2600 in a wireless communication system according to an embodiment of the present disclosure. (Refer to...) Figure 26 UE2600 may include a transceiver 2620, a memory 2630, and a processor 2610, which function as a terminal receiver and a terminal transmitter. The transceiver 2620, memory 2630, and processor 2610 of UE2600 can operate according to the communication method of UE2600 described above. However, the components of UE2600 are not limited thereto. For example, UE2600 may include more or fewer components than those described above. Furthermore, the transceiver 2620, memory 2630, and processor 2610 may be implemented as a single chip.

[0693] Transceiver 2620 can transmit signals to or receive signals from a base station. These signals may include control information and data. In this regard, transceiver 2620 may include an RF transmitter for up-converting and amplifying the frequency of the transmitted signal, and an RF receiver for amplifying the frequency of the received signal with low noise and down-converting it. However, this is merely an example of transceiver 2620, and its components are not limited to RF transmitters and RF receivers.

[0694] In addition, transceiver 2620 can receive signals via a radio channel and output them to processor 2610, and can also transmit signals output from processor 2610 via a radio channel.

[0695] The memory 2630 can store programs and data required for the operation of the UE 2600. Furthermore, the memory 2630 can store control information or data included in signals sent and received by the UE 2600. The memory 2630 can be a storage medium, such as a read-only memory (ROM), random access memory (RAM), hard disk, CD-ROM, and DVD, or a combination of storage media. Multiple memories 2630 may be present.

[0696] Processor 2610 can control a series of processes that enable UE 2600 to operate according to the embodiments disclosed above. For example, processor 2610 can control components of UE 2600 to simultaneously receive multiple PDSCHs by receiving a two-layer DCI. Multiple processors 2610 may be present, and each processor 2610 can execute a program stored in memory 2630 to control components of UE 2600.

[0697] Figure 27 A structural diagram of a base station 2700 in a wireless communication system according to an embodiment of the present disclosure is shown.

[0698] Reference Figure 27 The base station 2700 may include a transceiver 2720, a memory 2730, and a processor 2710, which serve as a base station receiver and a base station transmitter. The transceiver 2720, memory 2730, and processor 2710 of the base station 2700 can operate according to the communication method of the base station 2700 described above. However, the components of the base station 2700 are not limited thereto. For example, the base station 2700 may include more or fewer components than described above. Furthermore, the transceiver 2720, memory 2730, and processor 2710 may be implemented as a single chip.

[0699] Transceiver 2720 can transmit signals to or receive signals from the UE. These signals may include control information and data. In this regard, transceiver 2720 may include an RF transmitter for up-converting and amplifying the frequency of the transmitted signal, and an RF receiver for amplifying the frequency of the received signal with low noise and down-converting it. However, this is merely an example of transceiver 2720, and its components are not limited to RF transmitters and RF receivers.

[0700] In addition, transceiver 2720 can receive signals via a radio channel and output them to processor 2710, and can also transmit signals output from processor 2710 via a radio channel.

[0701] The memory 2730 can store the programs and data required for the operation of the base station 2700. Furthermore, the memory 2730 can store control information or data included in the signals transmitted and received by the base station 2700. The memory 2730 can be a storage medium, such as a read-only memory (ROM), random access memory (RAM), hard disk, CD-ROM, and DVD, or a combination of storage media. Multiple memories 2730 can be present.

[0702] Processor 2710 can control a series of processes that enable base station 2700 to operate according to the embodiments disclosed above. For example, processor 2710 can control each component of base station 2700 to configure and transmit two-layer DCI including allocation information for multiple PDSCHs. Multiple processors 2710 may be present, and each processor 2710 can execute programs stored in memory 2730 to control components of base station 2700.

[0703] The methods of embodiments of this disclosure described in the claims or in the detailed description of this disclosure can be implemented in hardware, software, or a combination of hardware and software.

[0704] When these methods are implemented in software, a computer-readable recording medium on which one or more programs (software modules) are recorded may be provided. The one or more programs recorded on the computer-readable recording medium are configured to be executable by one or more processors in a device. The one or more programs include instructions for performing the methods of embodiments of this disclosure as described in the claims or the detailed description of this disclosure.

[0705] The program (e.g., a software module or software) can be stored in random access memory (RAM), non-volatile memory including flash memory, read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), disk storage devices, optical discs (CD-ROM), digital versatile discs (DVDs), another type of optical storage device, or magnetic tape. Optionally, the program can be stored in a memory that includes some or all of the above-mentioned memories. Furthermore, multiple memories may be present.

[0706] The program can also be stored in an attachable storage device that can be accessed via a communication network such as the Internet, intranet, local area network (LAN), wireless LAN (WLAN), or storage area network (SAN), or a combination thereof. According to embodiments of this disclosure, the storage device can be connected to the device via an external port. Another storage device on the communication network can also be connected to the device executing embodiments of this disclosure.

[0707] In the specific embodiments of this disclosure described above, the elements included in this disclosure are represented in singular or plural form. However, for ease of explanation, singular or plural forms are appropriately chosen, and this disclosure is not limited thereto. Thus, an element expressed in plural form can also be configured as a single element, and an element expressed in singular form can also be configured as multiple elements.

[0708] Furthermore, the embodiments of this disclosure described with reference to this specification and accompanying drawings are merely illustrative examples to facilitate description and understanding of specific examples of this disclosure, and are not intended to limit the scope of this disclosure. In other words, other modifications based on the technical concept of this disclosure are feasible for those skilled in the art. Moreover, the embodiments of this disclosure can be combined with each other as needed. For example, a portion of one embodiment of this disclosure and a portion of another embodiment of this disclosure can be combined with each other to enable the base station and the UE to operate. For example, portions of the first embodiment and the second embodiment of this disclosure can be combined with each other to enable the base station and the UE to operate. Furthermore, the embodiments of this disclosure are provided based on an FDD LTE system, but other modifications based on the technical concept of the embodiments of this disclosure can be implemented on other systems, such as TDD LTE systems, 5G or NR systems, etc.

[0709] Furthermore, the order described in the accompanying drawings used to describe the methods of this disclosure does not necessarily correspond to the order of execution, and this order can be changed or executed in parallel.

[0710] Optionally, in the accompanying drawings used to describe the methods of this disclosure, some components may be omitted, and only some components may be included without departing from the essence of this disclosure.

[0711] Furthermore, without departing from the spirit and scope of this disclosure, the methods of this disclosure may be performed in combination of some or all of the elements included in each embodiment of this disclosure.

[0712] According to various embodiments of this disclosure, a method for transmitting and receiving uplink phase tracking reference signals to and from multiple transmitters / receivers in a network cooperative communication system is provided, along with an apparatus for performing the method. Therefore, better performance gains can be achieved.

[0713] Although this disclosure has been described with reference to various embodiments, various changes and modifications will be apparent to those skilled in the art. This disclosure is intended to include such changes and modifications that fall within the scope of the appended claims.

Claims

1. A method performed by a user equipment (UE) for transmitting a Physical Uplink Shared Channel (PUSCH), the method comprising: Receive SRS configuration information including at least a first detection reference signal (SRS) resource set and a second SRS resource set; Receive downlink control information (DCI) from the PUSCH scheduler. The DCI includes Phase Tracking Reference Signal-Demodulation Reference Signal (PTRS-DMRS) association information, First SRS Resource Indicator (SRI) information, and Second SRI information. The most significant bit (MSB) of the PTRS-DMRS association information indicates the first association between the PTRS port and the DMRS port corresponding to the first SRI information, and The least significant bit (LSB) of the PTRS-DMRS association information indicates the second association between the PTRS port and the DMRS port corresponding to the second SRI information; and The PTRS of PUSCH is sent based on the first association between the PTRS port and DMRS port corresponding to the first SRI information and the second association between the PTRS port and DMRS port corresponding to the second SRI information.

2. The method according to claim 1, further comprising: Based on the first SRI information and the second SRI information, identify the actual number of PTRS ports for each SRS resource set.

3. The method according to claim 1, further comprising: The actual number of PTRS ports is identified based on at least one Transport Precoding Matrix Indicator (TPMI) information, wherein the DCI also includes the at least one TPMI information.

4. The method according to claim 1, wherein, The first SRI information is associated with the first SRS resource set, and the second SRI information is associated with the second SRS resource set.

5. The method according to claim 1, wherein, DCI also includes additional PTRS-DMRS association information.

6. The method according to claim 1, wherein, Sending PUSCH includes non-codebook-based PUSCH transmission or codebook-based PUSCH transmission.

7. A user equipment (UE) configured to transmit a Physical Uplink Shared Channel (PUSCH), the UE comprising: transceiver; and At least one processor, coupled to a transceiver, is configured to: Receive SRS configuration information including at least a first detection reference signal (SRS) resource set and a second SRS resource set. Receive downlink control information (DCI) from the PUSCH scheduler. The DCI includes Phase Tracking Reference Signal-Demodulation Reference Signal (PTRS-DMRS) association information, First SRS Resource Indicator (SRI) information, and Second SRI information. The most significant bit (MSB) of the PTRS-DMRS association information indicates the first association between the PTRS port and the DMRS port corresponding to the first SRI information, and The least significant bit (LSB) of the PTRS-DMRS association information indicates the second association between the PTRS port and the DMRS port corresponding to the second SRI information, and The PTRS of PUSCH is sent based on the first association between the PTRS port and DMRS port corresponding to the first SRI information and the second association between the PTRS port and DMRS port corresponding to the second SRI information.

8. A method performed by a base station for receiving a Physical Uplink Shared Channel (PUSCH), the method comprising: Send SRS configuration information to the user equipment (UE) including at least a first sounding reference signal (SRS) resource set and a second SRS resource set; Send downlink control information (DCI) for scheduling PUSCH to the UE. The DCI includes Phase Tracking Reference Signal-Demodulation Reference Signal (PTRS-DMRS) association information, First SRS Resource Indicator (SRI) information, and Second SRI information. The most significant bit (MSB) of the PTRS-DMRS association information indicates the first association between the PTRS port and the DMRS port corresponding to the first SRI information, and The least significant bit (LSB) of the PTRS-DMRS association information indicates the second association between the PTRS port and the DMRS port corresponding to the second SRI information; and Based on the first association between the PTRS port and DMRS port corresponding to the first SRI information or the second association between the PTRS port and DMRS port corresponding to the second SRI information, the PTRS of the PUSCH is received from the UE.

9. The method according to claim 8, wherein, The actual number of PTRS ports for each SRS resource set is identified at the UE based on the first SRI information and the second SRI information.

10. The method according to claim 8, wherein, The actual number of PTRS ports is based on at least one Transport Precoding Matrix Indicator (TPMI) information identified at the UE, wherein the DCI also includes the at least one TPMI information.

11. The method according to claim 8, wherein, The first SRI information is associated with the first SRS resource set, and the second SRI information is associated with the second SRS resource set.

12. The method according to claim 8, wherein, DCI also includes additional PTRS-DMRS association information.

13. The method according to claim 8, wherein, Receiving PUSCH includes non-codebook-based PUSCH reception or codebook-based PUSCH reception.

14. A base station configured to receive a Physical Uplink Shared Channel (PUSCH), the base station comprising: transceiver; and At least one processor, coupled to a transceiver, is configured to: Send SRS configuration information to the user equipment (UE) including at least a first sounding reference signal (SRS) resource set and a second SRS resource set; Send downlink control information (DCI) for scheduling PUSCH to the UE. The DCI includes Phase Tracking Reference Signal-Demodulation Reference Signal (PTRS-DMRS) association information, First SRS Resource Indicator (SRI) information, and Second SRI information. The most significant bit (MSB) of the PTRS-DMRS association information indicates the first association between the PTRS port and the DMRS port corresponding to the first SRI information, and The least significant bit (LSB) of the PTRS-DMRS association information indicates the second association between the PTRS port and the DMRS port corresponding to the second SRI information; and Based on the first association between the PTRS port and DMRS port corresponding to the first SRI information or the second association between the PTRS port and DMRS port corresponding to the second SRI information, the PTRS of the PUSCH is received from the UE.

Images