Method and apparatus for interpreting downlink control information in a wireless communication system - Patents.com

Abstract

Provided are terminals and base stations in 5G or 6G wireless communication systems and methods performed thereby for supporting higher data transmission rates. [Solution] A method performed by a terminal in a wireless communication system of the present invention includes the steps of receiving an upper layer signal including time domain resource assignment (TDRA) information from a base station, receiving downlink control information (DCI) including an antenna port field from the base station, and, if the DCI includes multiple scheduling information of different mapping types, identifying an antenna port table of a first mapping type and an antenna port table of a second mapping type based on the antenna port field.

Description

[Technical field]

[0001] The present invention relates to the operation of a terminal and a base station in a wireless communication system, and more particularly to a method and an apparatus for a terminal to interpret an antenna port field in a downlink control information (DCI) format. The present invention also relates to a method and an apparatus for a terminal to interpret a phase tracking reference signal (PTRS) related field in a DCI format. [Background technology]

[0002] 5G mobile communication technology defines a wide frequency band to enable high transmission rates and new services, and is being implemented not only in the sub-6GHz band such as 3.5GHz, but also in the ultra-high frequency band known as mmWave (Above 6GHz) such as 28GHz and 39GHz. In addition, in the case of 6G mobile communication technology, known as the Beyond 5G system, implementation in the terahertz band (e.g. 95GHz or 3THz band) is being considered to achieve transmission speeds 50 times faster than 5G mobile communication technology and ultra-low latency times that are one-tenth of that of 5G mobile communication technology.

[0003] In the early stage of 5G mobile communication technology, the following technologies are being proposed: Beamforming and Massive MIMO to mitigate path loss and increase propagation distance in ultra-high frequency bands, various neurology support (e.g., multiple subcarrier spacing control) and dynamic control of slot format for efficient use of ultra-high frequency resources, initial connection technology to support multiple beam transmission and wideband, definition and operation of Band-Width Part (BWP), new channel coding methods such as Low Density Parity Check (LDPC) code for large volume data transmission and Polar Code for reliable transmission of control information, L2 pre-processing, Network Slicing to provide a dedicated network specialized for specific services, Standardization of techniques such as slicing has been progressing.

[0004] Discussions are currently underway to improve and enhance the initial 5G mobile communications technology in consideration of the services that 5G mobile communications technology is intended to support. Physical layer standardization is underway for technologies such as Vehicle-to-Everything (V2X), which aims to increase user convenience by helping autonomous vehicles make driving decisions based on their own position and status information sent by the vehicle, New Radio Unlicensed (NR-U), which aims to operate systems that comply with various regulatory requirements in unlicensed bands, low power consumption technology for NR terminals (UE Power Saving), Non-Terrestrial Network (NTN), which is direct communication between terminals and satellites to ensure coverage in areas where communication with terrestrial networks is not possible, and positioning.

[0005] In addition, standardization is underway for air interface architecture / protocols for technologies such as Industrial Internet of Things (IIOT) to support new services through collaboration and integration with other industries, Integrated Access and Backhaul (IAB) to provide nodes for expanding network service areas by integrating wireless backhaul links and access links, mobility enhancement technologies including Conditional Handover and Dual Active Protocol Stack (DAPS) handover, and 2-step random access (2-step RACH for NR) to simplify random access procedures. Standardization is also underway in the system architecture / service field for 5G baseline architecture (e.g., Service based Architecture, Service based Interface) to combine Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) to receive services based on the location of the terminal.

[0006] As the 5G mobile communication system is commercialized, an explosive increase in connected devices will be connected to the communication network. Accordingly, it is expected that the 5G mobile communication system will require improved functions and performance, as well as integrated operation of connected devices. For this reason, new research will be conducted on eXtended Reality (XR) to efficiently support Augmented Reality (AR), Virtual Reality (VR), Mixed Reality (MR), etc., 5G performance improvement and complexity reduction using Artificial Intelligence (AI) and Machine Learning (ML), AI service support, Metabus service support, drone communication, etc.

[0007] In addition, the development of such 5G mobile communication systems will be the basis for the development of new waveforms to ensure coverage in the terahertz band of 6G mobile communication technology, multi-antenna transmission technologies such as full dimensional multiple input / output (FD-MIMO), array antennas, and large scale antennas, metamaterial-based lenses and antennas to improve the coverage of terahertz band signals, high-dimensional spatial multiplexing technology using orbital angular momentum (OAM), and reconfigurable intelligent surface (RIS) technology, as well as full duplex technology to improve the frequency efficiency of 6G mobile communication technology and improve system networks, AI-based communication technology that utilizes satellites and artificial intelligence (AI) from the design stage and incorporates end-to-end AI support functions to optimize the system, and next-generation distributed computing technology that utilizes ultra-high performance communication and computing resources to realize services with a level of complexity that exceeds the limits of terminal computing capabilities. Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made in view of the above-mentioned conventional techniques, and an object of the present invention is to provide an apparatus and method for effectively providing services in a mobile communication system. [Means for solving the problem]

[0009] The present invention has been made to solve the problems and shortcomings discussed above and to provide at least the advantages described below.

[0010] In order to achieve the above object, a method performed by a terminal in a wireless communication system according to one aspect of the present invention includes the steps of receiving an upper layer signal including time domain resource assignment (TDRA) information from a base station, receiving downlink control information (DCI) including an antenna port field from the base station, and if the DCI includes multiple scheduling information of different mapping types, identifying an antenna port table of a first mapping type and an antenna port table of a second mapping type based on the antenna port field.

[0011] In order to achieve the above object, a method performed by a base station in a wireless communication system according to one aspect of the present invention includes a step of transmitting an upper layer signal including time domain resource assignment (TDRA) information to a terminal, and a step of transmitting downlink control information (DCI) including an antenna port field to the terminal, and is characterized in that when the DCI includes multiple scheduling information of different mapping types, an antenna port table of a first mapping type and an antenna port table of a second mapping type are identified based on the antenna port field.

[0012] According to one aspect of the present invention made to achieve the above object, a terminal in a wireless communication system includes a transceiver unit and a control unit, and the control unit is configured to receive an upper layer signal including time domain resource assignment (TDRA) information from a base station, receive downlink control information (DCI) including an antenna port field from the base station, and when the DCI includes multiple scheduling information of different mapping types, identify an antenna port table of a first mapping type and an antenna port table of a second mapping type based on the antenna port field.

[0013] In order to achieve the above object, a base station in a wireless communication system according to one embodiment of the present invention comprises a transceiver unit and a control unit, and the control unit is configured to transmit an upper layer signal including time domain resource assignment (TDRA) information to a terminal and transmit downlink control information (DCI) including an antenna port field to the terminal, and when the DCI includes multiple scheduling information of different mapping types, an antenna port table of a first mapping type and an antenna port table of a second mapping type are identified based on the antenna port field. Effect of the Invention

[0014] According to the present invention, it is possible to provide a method and an apparatus capable of effectively providing services in a mobile communication system, in which a terminal interprets an antenna port field of a DCI format and a terminal interprets a PTRS-related field of a DCI format. [Brief description of the drawings]

[0015] [Figure 1] FIG. 2 is a diagram illustrating a basic structure of the time-frequency domain in a wireless communication system according to one embodiment. [Diagram 2] FIG. 2 illustrates a frame, subframe, and slot structure in a wireless communication system according to one embodiment. [Diagram 3] FIG. 1 illustrates an example of bandwidth portion setting in a wireless communication system according to one embodiment. [Figure 4] A diagram showing a control region configuration of a downlink control channel in a wireless communication system according to one embodiment. [Diagram 5] FIG. 2 illustrates a structure of a downlink control channel in a wireless communication system according to one embodiment. [Figure 6]1 is a diagram illustrating a method in which a base station and a terminal transmit and receive data taking into account a downlink data channel and rate matching resources in a wireless communication system according to an embodiment. [Figure 7] 1 is a diagram illustrating frequency axis resource allocation of a physical downlink shared channel (PDSCH) in a wireless communication system according to one embodiment. [Figure 8] 1 is a diagram showing time axis resource allocation of a PDSCH in a wireless communication system according to one embodiment. [Figure 9] FIG. 2 is a diagram illustrating time axis resource allocation based on subcarrier spacing of a data channel and a control channel in a wireless communication system according to one embodiment. [Figure 10] A diagram showing radio protocol structures of a base station and a terminal in single cell, carrier aggregation, and dual connectivity situations in a wireless communication system according to one embodiment. [Figure 11] FIG. 2 illustrates a PDSCH scheduling scheme according to one embodiment. [Figure 12] A diagram showing DCI for Single-PDSCH scheduling and Multi-PDSCH scheduling according to one embodiment. [Figure 13] FIG. 1 illustrates hybrid automatic repeat request (HARQ)-acknowledgement (ACK) transmission of one or more PDSCHs scheduled by a DCI when the DCI indicates Multi-PDSCH scheduling according to one embodiment. [Figure 14] FIG. 2 is a diagram illustrating the structure of a terminal in a wireless communication system according to an embodiment. [Figure 15] FIG. 2 is a diagram illustrating the structure of a base station in a wireless communication system according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, specific examples of the embodiment of the present invention will be described in detail with reference to the drawings. However, it should be understood that the various embodiments of the present invention are not limited to the specific embodiments, and various modifications, equivalents, and / or replacements of the embodiments described herein can be made. In the description of the drawings, similar elements are given similar reference numerals.

[0017] Various embodiments of the present invention provide a method for a terminal configured with multiple physical downlink shared channel (PDSCH) scheduling and multiple physical uplink shared channel (PUSCH) scheduling in a wireless communication system to interpret an antenna port field.

[0018] According to the multiple PDSCH scheduling and multiple PUSCH scheduling configuration, the terminal receives multiple scheduling information in one Time Domain Resource Assignment (TDRA) row, and each of the multiple scheduling information has a Starting and Length Indication Value (SLIV) and a mapping type. Therefore, the terminal according to various embodiments of the present invention receives an indication of a TDRA row including scheduling information having different mapping types through one DCI.

[0019] Different DMRS configuration information is set for different mapping types. When the DMRS configuration information is different, the antenna port table for indicating the DMRS port is different. According to various embodiments of the present invention, the DCI format for scheduling the PDSCH or PUSCH includes an antenna port field for indicating one row of the antenna port table.

[0020] When TDRA rows including scheduling information with different mapping types are indicated through one DCI, one DCI must indicate each row of multiple tables. In various embodiments of the present invention, a method for designing and interpreting an antenna port field included in a DCI format is provided to indicate each row of multiple antenna port tables.

[0021] Different DMRS configuration information is set for different mapping types. When the DMRS configuration information is different, the antenna port table for indicating the DMRS information is different. Therefore, different DMRS port(s) are assigned to different mapping types.

[0022] When a TDRA row including scheduling information having different mapping types is indicated through one DCI, the PTRS-DMRS association field indicates one of the DMRS port(s) of each of the two mapping types. Various methods are provided for this purpose in this specification.

[0023] In describing the embodiments of the present invention, technical details that are well known in the technical field to which the present invention pertains and are not directly related to the present invention will be omitted in order to clarify and more clearly convey the gist of the present invention by omitting unnecessary explanations.

[0024] For the same reason, some components are exaggerated, omitted, or illustrated in a schematic manner in the drawings, and the size of each component does not entirely reflect the actual size. The same or corresponding components in each drawing are denoted by the same reference numerals.

[0025] The advantages and features of the present invention and the method of achieving them will become apparent by referring to the embodiments described below in detail in conjunction with the drawings. However, the present invention is not limited to the embodiments described below, and can be implemented in various different forms. The following embodiments are provided only to fully disclose the present invention and inform those skilled in the art of the scope of the present invention defined by the claims. The same or similar reference numbers throughout the specification indicate the same or similar elements. In addition, in describing the present invention, detailed descriptions of known functions and configurations contained in this specification will be omitted if it is determined that the description may unnecessarily obscure the subject matter of the present invention. The terms described below are terms defined in consideration of the functions in the present invention, and may vary depending on the user, the user's intention, customs, etc. Therefore, the definitions of terms should be based on the contents of the entire specification.

[0026] It will be understood that each block of the process flow chart and the combination of the figures in the flow chart are implemented by computer program instructions. These computer program instructions may be loaded onto a processor of a general purpose computer, special purpose computer, or other programmable data processing device, such that the instructions executed by the processor of the computer or other programmable data processing device create means for performing the functions described in the flow chart blocks. These computer program instructions may also be stored in a computer usable or computer readable memory that directs the computer or other programmable data processing device to implement the functions in a particular manner, such that the instructions stored in the computer usable or computer readable memory may produce an article of manufacture that includes instruction means for performing the functions described in the flow chart blocks. The computer program instructions may also be loaded onto a computer or other programmable data processing device, such that a series of operational steps are performed on the computer or other programmable data processing device, such that the instructions to generate a computer implemented process to operate the computer or other programmable data processing device provide the steps for performing the functions described in the flow chart blocks.

[0027] Also, each block represents a module, segment, or portion of code that includes one or more executable instructions for performing a specified logical function. It should also be noted that in some alternative implementations, the functions noted in the blocks may occur out of order. For example, two blocks shown adjacent to each other may in fact be performed substantially simultaneously, or the blocks may sometimes be performed in reverse order depending on the corresponding functions.

[0028] In this embodiment, the term "module" refers to software or hardware components such as FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit), and the "module" performs such functions. However, the term "module" is not limited to software or hardware. The "module" may be configured to reside in an addressable storage medium, and may be configured to execute one or more processors. Thus, by way of example, the "module" includes components such as software components, object-oriented software components, class components, and task components, as well as processes, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The components and functions provided in the "module" may be combined into fewer components and "modules" or further separated into additional components and "modules". Furthermore, the components and "modules" may be embodied to execute one or more CPUs in a device or a secure multimedia card. Further, in an embodiment, a "unit" may include one or more processors.

[0029] Wireless communication systems have moved away from providing voice-centric services in the early days and have evolved into broadband wireless communication systems providing high-speed, high-quality packet data services, such as communication standards such as 3GPP® High Speed ​​Packet Access (HSPA), LTE (Long Term Evolution or E-UTRA (Evolved Universal Terrestrial Radio Access)), LTE-Advanced (LTE-A), LTE-Pro, 3GPP®2 High Rate Packet Data (HRPD), UMB (Ultra Mobile Broadband), and IEEE 802.16e.

[0030] As a representative example of a broadband wireless communication system, an 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). The uplink refers to a radio link through which a terminal (User Equipment (UE) or Mobile Station (MS)) transmits data or control signals to a base station (eNode B or base station (BS)), and the downlink refers to a radio link through which a base station transmits data or control signals to a terminal. The multiple access scheme as described above generally divides the data or control information of each user by allocating and operating time-frequency resources for transmitting data or control information for each user so as not to overlap with each other, i.e., to establish orthogonality.

[0031] As a communication system beyond LTE, i.e., 5G communication system, it is necessary to freely reflect the various requirements of users and service providers, and therefore it is necessary to support services that meet various requirements. Services considered for 5G communication system include eMBB (enhanced Mobile Broadband: eMBB), mMTC (massive Machine Type Communication), URLLC (Ultra Reliability Low Latency Communication), etc.

[0032] eMBB aims to provide a data transmission rate that is higher than the data transmission rate supported by existing LTE, LTE-A, or LTE-Pro. For example, in a 5G communication system, eMBB must provide a maximum transmission rate of 20 Gbps in the downlink and a maximum transmission rate of 10 Gbps in the uplink from the perspective of one base station. In addition, the 5G communication system must provide an increased user perceived data rate while providing the maximum transmission rate. To meet these requirements, it is required to improve various transmission and reception technologies, including improved multiple antenna (Multi Input Multi Output: MIMO) transmission technology. In addition, while LTE transmits signals using a maximum transmission bandwidth of 20 MHz in the 2 GHz band, the 5G communication system satisfies the data transmission rate required for the 5G communication system by using a frequency bandwidth wider than 20 MHz in the 3 to 6 GHz or 6 GHz or higher frequency band.

[0033] At the same time, mMTC is being considered to support application services such as the Internet of Things (IoT) in 5G communication systems. In order to efficiently provide the Internet of Things, mMTC is required to support the connection of large numbers of terminals within a cell, improve terminal coverage, improve battery life, and reduce terminal costs. The Internet of Things is attached to various sensors and various devices to provide communication functions, so it must support a large number of terminals (e.g., 1,000,000 terminals / km2) within a cell. In addition, because terminals supporting mMTC are likely to be located in shadow areas that cannot be covered by cells, such as the basement of a building, due to the characteristics of the service, it requires wider coverage than other services provided by the 5G communication system. Terminals supporting mMTC must be constructed inexpensively and have a very long battery life of 10 to 16 years because it is difficult to frequently replace the terminal battery.

[0034] Finally, URLLC is a cellular-based wireless communication service used for mission-critical purposes. For example, services used for remote control of robots or machinery, industrial automation, unmanned aerial vehicles, remote health care, emergency alerts, etc. are considered. Therefore, the communication provided by URLLC must provide very low latency and very high reliability. For example, services that support URLLC must satisfy an air interface latency of less than 0.5 milliseconds and at the same time have a packet error rate requirement of 10-5 or less. Therefore, for services that support URLLC, the 5G system must provide a shorter transmit time interval (TTI) than other services, and at the same time, design items are required in which wide resources must be allocated in the frequency band to ensure the reliability of the communication link.

[0035] The three 5G services, i.e. eMBB, URLLC, and mMTC, are multiplexed and transmitted in one system. In this case, different transmission and reception techniques and transmission and reception parameters are used between the services to meet the different requirements of each service. Of course, 5G is not limited to the above three services.

[0036] This section explains NR time-frequency resources.

[0037] FIG. 1 is a diagram showing the basic structure of a time-frequency domain in a wireless communication system according to one embodiment, and shows the basic structure of a time-frequency domain, which is a radio resource domain in which data or control channels are transmitted in a 5G system.

[0038] In Fig. 1, the horizontal axis indicates the time domain, and the vertical axis indicates the frequency domain. The basic unit of a resource in the time and frequency domains is defined as a resource element (RE) 101, which is one OFDM (Orthogonal Frequency Division Multiplexing) symbol 102 on the time axis, and one subcarrier 103 on the frequency axis. In the frequency domain, TIFF2025511982000002.tif9128 (e.g., 12) consecutive REs constitute one resource block (RB) 104. One subframe 110 is made up of multiple OFDM symbols. For example, the length of the subframe 110 is 1 ms.

[0039] FIG. 2 is a diagram illustrating a frame, subframe, and slot structure in a wireless communication system according to one embodiment.

[0040] FIG. 2 shows an example of a frame 200, subframe 201, and slot 202 structure. One frame 200 is defined as 10 ms. One subframe 201 is defined as 1 ms, and therefore one frame 200 is composed of a total of 10 subframes 201. One slot (202, 203) is defined as 14 OFDM symbols (i.e., the number of symbols per slot is 14). TIFF2025511982000003.tif111281 A subframe 201 is made up of one or more slots (202, 203), and the number of slots (202, 203) per subframe 201 varies depending on the set value μ (204, 205) for the subcarrier spacing. The example in FIG. 2 shows the cases where the subcarrier wave spacing set value is μ=0 (204) and μ=1 (205). When μ=0 (204), one subframe 201 is made up of one slot 202, and when μ=1 (205), one subframe 201 is made up of two slots 203. In other words, the number of slots per subframe varies depending on the set value μ for the subcarrier spacing. TIFF2025511982000004.tif11128 is changed, which changes the number of slots per frame. TIFF2025511982000005.tif11128 changes depending on the subcarrier spacing setting μ TIFF2025511982000006.tif10128 is defined in Table 1 below.

[0041] [Table 1]

[0042] Next, the setting of the bandwidth part (BWP) in the 5G communication system will be described in detail with reference to the drawings.

[0043] FIG. 3 is a diagram illustrating an example of bandwidth portion setting in a wireless communication system according to an embodiment.

[0044] 3 shows an example in which a terminal bandwidth (UE bandwidth) 300 is set to two bandwidth parts, i.e., a bandwidth part #1 (BWP#1) 301 and a bandwidth part #2 (BWP#2) 302. The base station sets one or more bandwidth parts to the terminal, and sets information such as that shown in Table 2 below for each bandwidth part.

[0045] [Table 2]

[0046] Of course, various parameters related to the bandwidth portion other than the configuration information are configured in the terminal, without being limited to the above example. The information is transmitted from the base station to the terminal through higher layer signaling, for example, Radio Resource Control (RRC) signaling. At least one of the configured one or more bandwidth portions is activated. Whether or not to activate the configured bandwidth portion is semi-statically transmitted from the base station to the terminal through RRC signaling, or dynamically transmitted through Downlink Control Information (DCI).

[0047] According to some embodiments, a terminal before a Radio Resource Control (RRC) connection is configured with an initial bandwidth portion (Initial BWP) for initial connection from a base station through a Master Information Block (MIB). More specifically, in an initial connection stage, the terminal receives configuration information for a control region (CORESET) and a search space in which a PDCCH for receiving system information (Remaining System Information: RMSI or System Information Block 1: SIB1) required for initial connection is transmitted. The control region and search space configured in the MIB are regarded as respective identity (ID) 0. The base station notifies the terminal of configuration information such as frequency allocation information, time allocation information, and numerology for the control region #0 through the MIB. In addition, the base station notifies the terminal of configuration information for a monitoring period and occasion for the control region #0, i.e., configuration information for the search space #0, through the MIB. The terminal regards the frequency region configured in the control region #0 acquired from the MIB as an initial bandwidth portion for initial connection. At this time, the identifier (ID) of the initial bandwidth portion is considered to be 0.

[0048] The configuration for the bandwidth portion supported by 5G is used for various purposes.

[0049] In some embodiments, when the bandwidth supported by the terminal is smaller than the system bandwidth, this is supported through bandwidth portion configuration. For example, the base station configures the frequency position of the bandwidth portion (configuration information 2) to the terminal, so that the terminal transmits and receives data at a specific frequency position within the system bandwidth.

[0050] In some embodiments, a base station configures multiple bandwidth portions for a terminal in order to support different neurologies. For example, to support data transmission and reception using a subcarrier interval of 15 kHz and a subcarrier interval of 30 kHz for a certain terminal, two bandwidth portions are configured with subcarrier intervals of 15 kHz and 30 kHz, respectively. The different bandwidth portions are frequency division multiplexed, and when data is to be transmitted or received at a specific subcarrier interval, the bandwidth portion configured at the specific subcarrier interval is activated.

[0051] Also, according to some embodiments, in order to reduce power consumption of the terminal, the base station sets bandwidth portions having different bandwidths to the terminal. For example, if the terminal supports a very large bandwidth, for example, a bandwidth of 100 MHz, and constantly transmits and receives data in the bandwidth, a very large power consumption occurs. In particular, monitoring unnecessary downlink control channels in a large bandwidth of 100 MHz in a situation where there is no traffic is very inefficient in terms of power consumption. In order to reduce power consumption of the terminal, the base station sets a bandwidth portion having a relatively small bandwidth, for example, a bandwidth portion of 20 MHz, to the terminal. In a situation where there is no traffic, the terminal performs a monitoring operation in the 20 MHz bandwidth portion, and when data is generated, transmits and receives data in the 100 MHz bandwidth portion according to an instruction from the base station.

[0052] In the method of setting the bandwidth part, a terminal before an RRC connection (Connected) receives setting information for the initial bandwidth part through a master information block (MIB) in an initial connection stage. More specifically, a control region (Control Resource Set: CORESET) for a downlink control channel in which downlink control information (DCI) for scheduling a system information block (SIB) is transmitted from the MIB of a physical broadcast channel (PBCH) is set in the terminal. The bandwidth of the control region set in the MIB is regarded as the initial bandwidth part, and the terminal receives a physical downlink shared channel (PDSCH) in which an SIB is transmitted through the set initial bandwidth part. The initial bandwidth part is used for other system information (OSI), paging, and random access in addition to receiving SIBs.

[0053] Explain the change in Bandwidth Part (BWP).

[0054] When one or more bandwidth parts are configured for the terminal, the base station uses a bandwidth part indicator field in the DCI to instruct the terminal to change (or switch, transition) to the bandwidth part. For example, in FIG. 3, if the currently activated bandwidth part of the terminal is bandwidth part #1 (301), the base station instructs the terminal to use the bandwidth part indicator in the DCI to indicate bandwidth part #2 (302), and the terminal changes the bandwidth part to bandwidth part #2 (302) indicated by the bandwidth part indicator in the received DCI.

[0055] As described above, since the DCI-based bandwidth part change is instructed by the DCI that schedules the PDSCH or PUSCH, when the UE receives a bandwidth part change request, it must receive or transmit the PDSCH or PUSCH scheduled by the DCI smoothly in the changed bandwidth part. For this purpose, the standard specifies requirements for the latency time (TBWP) required when changing the bandwidth part, and is defined as shown in Table 3, for example.

[0056] [Table 3]

[0057] The requirement for the change delay time of the bandwidth portion supports Type 1 or Type 2 depending on the capability of the terminal. The terminal reports the bandwidth portion delay time type that it can support to the base station.

[0058] According to the above requirements for the bandwidth portion change delay time, when the terminal receives a DCI including a bandwidth portion change indicator in slot n, the terminal completes the change to the new bandwidth portion indicated by the bandwidth portion change indicator at a time not later than slot n+TBWP, and performs transmission / reception for the data channel scheduled by the DCI in the changed new bandwidth portion. When the base station is going to schedule a data channel in the new bandwidth portion, it determines the time domain resource allocation for the data channel by considering the bandwidth portion change delay time (TBWP) of the terminal. That is, when the base station schedules a data channel in the new bandwidth portion, it schedules the data channel after the bandwidth portion change delay time in the manner of determining the time domain resource allocation for the data channel. Thus, the terminal does not expect the DCI instructing the bandwidth portion change to indicate a slot offset (K0 or K2) value smaller than the bandwidth portion change delay time (TBWP).

[0059] When the terminal receives a DCI (e.g., DCI format 1_1 or 0_1) indicating a bandwidth portion change, the terminal does not transmit or receive during a time period corresponding to a time interval from the third symbol of a slot in which a PDCCH including the DCI is received to the start of a slot indicated by a time domain resource allocation indicator field and an indicated slot offset (K0 or K2) value in the DCI. For example, if the terminal receives a DCI indicating a bandwidth portion change in slot n and the slot offset value indicated in the DCI is K, the terminal does not transmit or receive from the third symbol of slot n to the symbol before slot n+K (i.e., the last symbol of slot n+K-1).

[0060] The SS / PBCH block will now be described.

[0061] Next, the SS (Synchronization Signal) / PBCH block in 5G will be explained. The SS / PBCH block refers to a physical layer channel block composed of PSS (Primary SS), SSS (Secondary SS), and PBCH. Specifically, it is as follows.

[0062] -PSS is a signal that serves as a reference for downlink time / frequency synchronization and provides some information of the cell ID.

[0063] -SSS is a signal that serves as a reference for downlink time / frequency synchronization and provides remaining cell ID information not provided by PSS. In addition, it serves as a reference signal for demodulation of PBCH.

[0064] -PBCH is a channel that provides essential system information required for transmission and reception of data channels and control channels of a terminal. The essential system information includes search space related control information indicating radio resource mapping information of a control channel, scheduling control information for a separate data channel that transmits system information, etc.

[0065] -SS / PBCH block: The SS / PBCH block is a combination of PSS, SSS, and PBCH. One or more SS / PBCH blocks are transmitted within a 5 ms time period, and each transmitted SS / PBCH block is identified by an index.

[0066] In the initial access stage, the terminal detects the PSS and SSS and decodes the PBCH. The terminal acquires the MIB from the PBCH, and a control region (Control Resource Set: CORESET) #0 (corresponding to the control region with a control region index of 0) is set from this. The terminal monitors the control region #0, assuming that the selected SS / PBCH block and the demodulation reference signal (DMRS) transmitted from the control region #0 are QCL (quasi co-located). The terminal receives system information in the downlink control information transmitted from the control region #0. The terminal acquires setting information related to the random access channel (RACH) required for the initial access from the received system information. The terminal transmits a physical RACH (PRACH) to the base station in consideration of the selected SS / PBCH index, and the base station receiving the PRACH acquires information on the SS / PBCH block index selected by the terminal. The base station knows which block of each SS / PBCH block the terminal has selected and the associated control region #0 to monitor.

[0067] Next, the downlink control information (DCI) in the 5G system will be described in detail.

[0068] In a 5G system, scheduling information for uplink data (or Physical Uplink Shared Channel (PUSCH)) or downlink data (or Physical Downlink Shared Channel (PDSCH)) is transmitted from a base station to a terminal through DCI. The terminal monitors a fallback DCI format and a non-fallback DCI format for PUSCH or PDSCH. The fallback DCI format is composed of fixed fields previously defined between the base station and the terminal, and the non-fallback DCI format includes configurable fields.

[0069] DCI is transmitted through the Physical Downlink Control Channel (PDCCH), a physical downlink control channel, after undergoing channel coding and modulation processes. A Cyclic Redundancy Check (CRC) is attached to the DCI message payload, and the CRC is scrambled with a Radio Network Temporary Identifier (RNTI) corresponding to the identity of the terminal. Different RNTIs are used depending on the purpose of the DCI message, such as UE-specific data transmission, power control command, or random access response. In other words, the RNTI is not transmitted explicitly, but is included in the CRC calculation process and transmitted. When the terminal receives a DCI message transmitted on the PDCCH, the terminal checks the CRC using the assigned RNTI, and if the CRC check result is correct, the terminal knows that the message was transmitted to the terminal.

[0070] For example, DCI for scheduling a PDSCH for system information (SI) is scrambled with SI-RNTI. DCI for scheduling a PDSCH for a Random Access Response (RAR) message is scrambled with RA-RNTI. DCI for scheduling a PDSCH for a paging message is scrambled with P-RNTI. DCI for reporting a Slot Format Indicator (SFI) is scrambled with SFI-RNTI. DCI for reporting Transmit Power Control (TPC) is scrambled with TPC-RNTI. DCI for scheduling a UE-specific PDSCH or PUSCH is scrambled with Cell RNTI (C-RNTI).

[0071] DCI format 0_0 is used in fallback DCI for scheduling PUSCH, and the CRC is scrambled by the C-RNTI at this time. DCI format 0_0 in which the CRC is scrambled by the C-RNTI includes, for example, the information in Table 4.

[0072] [Table 4]

[0073] DCI format 0_1 ​​is used for non-fallback DCI scheduling PUSCH, and the CRC is scrambled by the C-RNTI. DCI format 0_1 ​​with the CRC scrambled by the C-RNTI includes, for example, the information in Table 5.

[0074] [Table 5] TIFF2025511982000012.tif134169

[0075] DCI format 1_0 is used in fallback DCI for scheduling PDSCH, and the CRC is scrambled by the C-RNTI at this time. DCI format 1_0 in which the CRC is scrambled by the C-RNTI includes, for example, the information in Table 6.

[0076] [Table 6]

[0077] DCI format 1_1 is used in non-fallback DCI for scheduling PDSCH, and the CRC is scrambled by the C-RNTI at this time. DCI format 1_1 in which the CRC is scrambled by the C-RNTI includes, for example, the information in Table 7.

[0078] [Table 7]

[0079] Hereinafter, the downlink control channel in the 5G communication system will be described in more detail with reference to the drawings.

[0080] FIG. 4 is a diagram showing a control region setting of a downlink control channel in a wireless communication system according to one embodiment, and is a diagram showing an example of a control region (Control Resource Set: CORESET) in which the downlink control channel is transmitted in a 5G wireless communication system.

[0081] FIG. 4 shows an example in which a UE bandwidth part 410 is set on the frequency axis, and two control regions (control region #1 (401) and control region #2 (402)) are set within one slot 420 on the time axis. The control regions (401, 402) are set in specific frequency resources 403 within the entire UE bandwidth part 410 on the frequency axis. The control region is set as one or more OFDM symbols on the time axis, and is defined by the control region length (Control Resource Set Duration) 404. Referring to the example shown in FIG. 4, control region #1 (401) is set with a control region length of two symbols, and control region #2 (402) is set with a control region length of one symbol.

[0082] The above-mentioned control region in 5G is set by the base station to the terminal through higher layer signaling (e.g., system information, MIB (Master Information Block), RRC (Radio Resource Control) signaling). Setting a control region in the terminal means providing information such as a control region identity, a frequency position of the control region, and a symbol length of the control region. For example, the information in Table 8 is included.

[0083] [Table 8]

[0084] In Table 8, the tci-StatesPDCCH (simply referred to as TCI (Transmission Configuration Indication) state) configuration information includes information on one or more SS (Synchronization Signal) / PBCH (Physical Broadcast Channel) block indexes or CSI-RS (Channel State Information Reference Signal) indexes that are in a quasi-co-located relationship with the DMRS transmitted in the corresponding control region.

[0085] FIG. 5 is a diagram showing the structure of a downlink control channel in a wireless communication system according to one embodiment, and is a diagram showing an example of a basic unit of time and frequency resources constituting the downlink control channel used in 5G.

[0086] 5, a basic unit of time and frequency resources constituting a control channel is called a Resource Element Group (REG) 503, and the REG 503 is defined as one OFDM symbol 501 on the time axis and one Physical Resource Block (PRB) 502 on the frequency axis, i.e., 12 subcarriers. The base station configures a downlink control channel allocation unit by connecting the REGs 503.

[0087] As shown in FIG. 5, when a basic unit to which a downlink control channel is allocated in 5G is a CCE (Control Channel Element) 504, one CCE 504 is composed of a plurality of REGs 503. Taking the REG 503 shown in FIG. 5 as an example, the REG 503 is composed of 12 REs, and when one CCE 504 is composed of six REGs 503, one CCE 504 is composed of 72 REs. When a downlink control region is set, the region is composed of a plurality of CCEs 504, and a specific downlink control channel is mapped and transmitted by one or a plurality of CCEs 504 according to an aggregation level (AL) in the control region. The CCEs 504 in the control region are divided into numbers, and the numbers of the CCEs 504 are assigned according to a logical mapping method.

[0088] The basic unit of the downlink control channel shown in FIG. 5, i.e., REG 503, includes both the RE to which DCI is mapped and the area to which DMRS 505, which is a reference signal for decoding the DCI, is mapped. As shown in FIG. 5, three DMRSs 505 are transmitted within one REG 503. The number of CCEs required to transmit the PDCCH is 1, 2, 4, 8, or 16 depending on the aggregation level (AL), and different numbers of CCEs are used to implement link adaptation of the downlink control channel. For example, when AL=L, one downlink control channel is transmitted through L CCEs. A terminal must detect a signal without knowing information about the downlink control channel, and a search space indicating a set of CCEs is defined for blind decoding. A search space is a set of downlink control channel candidates consisting of CCEs that a terminal must attempt to decode at a given aggregation level, and since there are various aggregation levels that bundle 1, 2, 4, 8, and 16 CCEs, a terminal has multiple search spaces. A search space set is defined as the set of search spaces at all configured aggregation levels.

[0089] Search spaces are classified into common search spaces and UE-specific search spaces. A certain group of UEs or all UEs search the common search space of the PDCCH to receive cell-common control information such as dynamic scheduling for system information and paging messages. For example, PDSCH scheduling allocation information for transmitting SIBs including cell operator information is received by searching the common search space of the PDCCH. In the case of a common search space, since a certain group of UEs or all UEs must receive the PDCCH, it is defined as a set of CCEs that have already been committed. Scheduling allocation information for UE-specific PDSCH or PUSCH is received by searching the UE-specific search space of the PDCCH. The UE-specific search space is UE-specifically defined as a function of the identity of the UE and various system parameters.

[0090] In 5G, parameters for the search space for the PDCCH are set to the terminal from the base station by higher layer signaling (e.g., SIB, MIB, RRC signaling). For example, the base station sets to the terminal the number of PDCCH candidates at each aggregation level L, the monitoring period for the search space, the symbol-by-symbol monitoring occasion in the slot for the search space, the search space type (common search space or terminal-specific search space), the combination of the DCI format and RNTI to be monitored in the search space, the control region index to be monitored in the search space, etc. For example, the information in Table 9 is included.

[0091] [Table 9] TIFF2025511982000017.tif81160

[0092] According to the configuration information, the base station configures one or more search space sets for the terminal. According to some embodiments, the base station configures search space set 1 and search space set 2 for the terminal, configures the terminal to monitor DCI format A scrambled by X-RNTI in the common search space in search space set 1, and configures the terminal to monitor DCI format B scrambled by Y-RNTI in the terminal-specific search space in search space set 2.

[0093] According to the configuration information, there are one or more search space sets in the common search space or the terminal-specific search space. For example, search space set #1 and search space set #2 are configured as common search spaces, and search space set #3 and search space set #4 are configured as terminal-specific search spaces.

[0094] The following DCI format and RNTI combinations are monitored in the common search space, including, but not limited to, the following examples:

[0095] DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI,CS-RNTI,SP-CSI-RNTI,RA-RNTI,TC-RNTI,P-RNTI,SI-RNTI

[0096] DCI format 2_0 with CRC scrambled by SFI-RNTI

[0097] DCI format 2_1 with CRC scrambled by INT-RNTI

[0098] DCI format 2_2 with CRC scrambled by TPC-PUSCH-RNTI,TPC-PUCCH-RNTI

[0099] DCI format 2_3 with CRC scrambled by TPC-SRS-RNTI

[0100] In the terminal-specific search space, the following DCI format and RNTI combinations are monitored, including, but not limited to, the following examples.

[0101] DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI,CS-RNTI,TC-RNTI

[0102] DCI format 1_0 / 1_1 with CRC scrambled by C-RNTI,CS-RNTI,TC-RNTI

[0103] The RNTI specified follows the definition and usage below.

[0104] C-RNTI (Cell RNTI): Used for terminal-specific PDSCH scheduling

[0105] TC-RNTI (Temporary Cell RNTI): Used for terminal-specific PDSCH scheduling

[0106] CS-RNTI (Configured Scheduling RNTI): Semi-statically configured UE-specific PDSCH scheduling

[0107] RA-RNTI (Random Access RNTI): Used for PDSCH scheduling in the random access phase

[0108] P-RNTI (Paging RNTI): PDSCH scheduling use when paging is transmitted

[0109] SI-RNTI (System Information RNTI): System information is transmitted for PDSCH scheduling

[0110] INT-RNTI (Interruption RNTI): Used to notify whether or not to puncture the PDSCH

[0111] TPC-PUSCH-RNTI (Transmit Power Control for PUSCH RNTI): Used to indicate power adjustment commands for PUSCH

[0112] TPC-PUCCH-RNTI (Transmit Power Control for PUCCH RNTI): Used to indicate power adjustment commands for PUCCH

[0113] TPC-SRS-RNTI (Transmit Power Control for SRS RNTI): Used to indicate power adjustment commands for SRS

[0114] The DCI formats specified above follow the example definitions in Table 10.

[0115] [Table 10]

[0116] In 5G, the search space for control domain p, search space set s, and aggregation level L is expressed as follows in Equation 1.

[0117]

number

[0118] The TIFF2025511982000020.tif11137 value corresponds to 0 for the common search space. In the case of a terminal-specific search space, the TIFF2025511982000021.tif10128 value corresponds to a value that changes according to the terminal ID (C-RNTI or ID set in the terminal by the base station) and time index.

[0119] In 5G, multiple search space sets are set to different parameters (e.g., parameters in Table 9), so that the set of search space sets monitored by the terminal at each time point changes. For example, if search space set #1 is set with an X-slot period and search space set #2 is set with a Y-slot period, and X and Y are different, the terminal monitors both search space set #1 and search space set #2 in a specific slot, and monitors either search space set #1 or search space set #2 in a specific slot.

[0120] PDSCH: Frequency resource allocation is described.

[0121] FIG. 6 is a diagram illustrating a method for a base station and a terminal to transmit and receive data in consideration of a downlink data channel and a rate matching resource in a wireless communication system according to an embodiment.

[0122] 6 shows a downlink data channel 601 and a rate matching resource 602. The base station configures one or multiple rate matching resources 602 for the UE through higher layer signaling (e.g., RRC signaling). Configuration information for the rate matching resource 602 includes time domain resource allocation information 603, frequency domain resource allocation information 604, and periodicity information 605. If some or all of the time and frequency resources of the scheduled data channel 601 overlap with the configured rate matching resource 602, the base station rate-matches and transmits the data channel 601 in the rate matching resource 602 part. The UE performs reception and decoding assuming that the data channel 601 is rate-matched in the rate matching resource 602 part.

[0123] The base station dynamically notifies the UE through DCI whether the data channel is rate-matched in the configured rate matching resource portion through additional configuration. Specifically, the base station selects a part of the configured rate matching resources, groups the selected resources into rate matching resource groups, and indicates whether the data channel is rate-matched with each rate matching resource group through DCI using a bitmap method. For example, if four rate matching resources RMR#1, RMR#2, RMR#3, and RMR#4 are configured for the UE, the base station configures RMG#1={RMR#1, RMR#2} and RMG#2={RMR#3, RMR#4}. {RMR#3, RMR#4} are configured as rate matching groups, and indicates in the form of a bitmap whether rate matching is performed in each of RMG#1 and RMG#2 using two bits of the DCI field for the UE. For example, the base station indicates '1' when rate matching is required, and indicates '0' when rate matching is not required.

[0124] FIG. 7 is a diagram illustrating an example of frequency axis resource allocation of a physical downlink shared channel (PDSCH) in a wireless communication system according to an embodiment.

[0125] FIG. 7 is a diagram showing three frequency axis resource allocation methods, type 0 (7-00), type 1 (7-05), and dynamic switch (7-10), which can be configured through higher layers in an NR wireless communication system.

[0126] Referring to FIG. 7, when a terminal is configured to use only resource type 0 through higher layer signaling (7-00), some downlink control information (DCI) for allocating a PDSCH to the terminal includes a bitmap consisting of NRBG bits. The conditions for this will be described later. At this time, NRBG means the number of resource block groups (RBGs) determined according to the BWP size allocated by the BWP indicator and the higher layer parameter rbg-Size as shown in Table 11 below, and data is transmitted to the RBG indicated as 1R according to the bitmap.

[0127] [Table 11]

[0128] If the terminal is configured to use only resource type 1 through higher layer signaling (7-05), some DCI that allocates PDSCH to the terminal is TIFF2025511982000023.tif1114 contains frequency axis resource allocation information consisting of 1 bit. The conditions for this will be explained later. Through this, the base station sets the starting VRB (7-20) and the length of the frequency axis resource to be allocated consecutively thereafter (7-25).

[0129] If a terminal is configured to use both resource type 0 and resource type 1 through higher layer signaling (7-10), a part of DCI for allocating a PDSCH to the terminal includes frequency axis resource allocation information consisting of the larger value (7-35) of the payload (7-15) for setting resource type 0 and the payload (7-20, 7-25) for setting resource type 1. This condition will be described later. At this time, one bit is added to the most significant bit (MSB) of the frequency axis resource allocation information in the DCI, and if the bit has a value of '0', it indicates that resource type 0 is to be used, and if the bit has a value of '1', it indicates that resource type 1 is to be used.

[0130] The following describes a time domain resource allocation method for a data channel in a next generation mobile communication system (5G or NR system).

[0131] The base station sets a table for time domain resource allocation information for a downlink data channel (Physical Downlink Shared Channel, PDSCH) and an uplink data channel (Physical Uplink Shared Channel, PUSCH) to the terminal through higher layer signaling (e.g., RRC signaling). For the PDSCH, a table consisting of a maximum of maxNrofDL-Allocations=16 entries is set, and for the PUSCH, a table consisting of a maximum of maxNrofUL-Allocations=16 entries is set. In one embodiment, the time domain resource allocation information includes PDCCH-to-PDSCH slot timing (corresponding to a slot-unit time interval between a time when a PDCCH is received and a time when a PDSCH scheduled by the received PDCCH is transmitted, denoted by K0), PDCCH-to-PUSCH slot timing (corresponding to a slot-unit time interval between a time when a PDCCH is received and a time when a PUSCH scheduled by the received PDCCH is transmitted, denoted by K2), information on the position and length of a start symbol in which a PDSCH or PUSCH is scheduled in a slot, a mapping type of a PDSCH or PUSCH, etc. For example, information such as the following Table 12 or Table 13 is transmitted from the base station to the terminal.

[0132] [Table 12]

[0133] [Table 13]

[0134] The base station notifies the terminal of one of the table entries for the above-mentioned time domain resource allocation information through L1 signaling (e.g., DCI) (e.g., indicated in a 'time domain resource allocation' field in the DCI). The terminal acquires time domain resource allocation information for the PDSCH or PUSCH based on the DCI received from the base station.

[0135] FIG. 8 is a diagram illustrating time axis resource allocation of a PDSCH in a wireless communication system according to an embodiment.

[0136] Referring to FIG. 8, the base station indicates the time axis position of the PDSCH resource based on the subcarrier spacing (SCS) (μPDSCH, μPDCCH) of the data channel and control channel, which are set using a higher layer, the scheduling offset (K0) value, and the OFDM symbol start position (8-00) and length (8-05) within one slot, which are dynamically indicated through DCI.

[0137] FIG. 9 is a diagram illustrating time axis resource allocation based on subcarrier spacing of a data channel and a control channel in a wireless communication system according to an embodiment.

[0138] 9, when the subcarrier intervals of the data channel and the control channel are the same (9-00, μPDSCH=μPDCCH), the slot numbers for data and control are the same, so the base station and the terminal generate a scheduling offset according to a predetermined slot offset K0. On the other hand, when the subcarrier intervals of the data channel and the control channel are different (9-05, μPDSCH≠μPDCCH), the slot numbers for data and control are different, so the base station and the terminal generate a scheduling offset according to a predetermined slot offset K0 based on the subcarrier interval of the PDCCH.

[0139] Next, a scheduling method for PUSCH transmission will be described. PUSCH transmission is dynamically scheduled by a UL grant in DCI or operates according to configured grant Type 1 or Type 2. Dynamic scheduling indication for PUSCH transmission is possible using DCI format 0_0 or 0_1.

[0140] Configured grant Type 1 PUSCH transmission is not received for the UL grant in DCI, but is semi-statically configured through the reception of configuredGrantConfig including rrc-ConfiguredUplinkGrant in Table 14 through higher level signaling. Configured grant Type 2 PUSCH transmission is semi-persistently scheduled by the UL grant in DCI after receiving configuredGrantConfig that does not include rrc-ConfiguredUplinkGrant in Table 14 through higher level signaling. When PUSCH transmission operates by configured grant, the parameters applied to PUSCH transmission are applied through configuredGrantConfig, which is the higher level signaling in Table 14, except for dataScramblingIdentityPUSCH, txConfig, codebookSubset, maxRank, and scaling of UCI-OnPUSCH provided in pusch-Config, which is the higher level signaling, in Table 15. When the terminal is provided with transformPrecoder in configuredGrantConfig, which is the higher level signaling in Table 14, the terminal applies tp-pi2BPSK in pusch-Config in Table 15 to PUSCH transmission operated by the configured grant.

[0141] [Table 14] TIFF2025511982000027.tif118169

[0142] Next, the PUSCH transmission method will be described. The DMRS antenna port for PUSCH transmission is the same as the antenna port for SRS transmission. PUSCH transmission follows a codebook-based transmission method or a non-codebook-based transmission method depending on whether the value of txConfig in pusch-Config in Table 14, which is higher signaling, is 'codebook' or 'nonCodebook'.

[0143] As described above, PUSCH transmission is dynamically scheduled through DCI format 0_0 or 0_1, or semi-statically configured by configured grant. When the terminal is instructed to schedule PUSCH transmission through DCI format 0_0, the terminal performs beam configuration for PUSCH transmission using pucch-spatialRelationInfoID corresponding to the terminal-specific PUCCH resource corresponding to the smallest ID in an activated uplink BWP in a serving cell, and at this time, PUSCH transmission is based on a single antenna port. The terminal does not expect scheduling for PUSCH transmission through DCI format 0_0 in a BWP in which a PUCCH resource including pucch-spatialRelationInfo is not configured. If the terminal does not configure txConfig in pusch-Config of Table 15, the terminal does not expect to be scheduled in DCI format 0_1.

[0144] [Table 15]

[0145] Next, a description will be given of codebook-based PUSCH transmission. Codebook-based PUSCH transmission is dynamically scheduled through DCI format 0_0 or 0_1, and operates semi-statically through configured grant. When Codebook-based PUSCH is dynamically scheduled through DCI format 0_1 ​​or semi-statically configured through configured grant, the UE determines a precoder for PUSCH transmission based on an SRS Resource Indicator (SRI), a Transmission Precoding Matrix Indicator (TPMI), and a transmission rank (the number of PUSCH transmission layers).

[0146] At this time, the SRI is given through a field SRS resource indicator in the DCI or is set through srs-ResourceIndicator, which is higher-level signaling. At least one SRS resource is set for the terminal when transmitting a Codebook-based PUSCH, and up to two SRS resources are set. When the SRI is provided to the terminal through the DCI, the SRS resource indicated by the SRI means an SRS resource corresponding to the SRI among SRS resources transmitted before the PDCCH including the SRI. In addition, the TPMI and the transmission rank are given through a field precoding information and number of layers in the DCI or are set through precodingAndNumberOfLayers, which is higher-level signaling. The TPMI is used to indicate a precoder applied to PUSCH transmission. When one SRS resource is configured for the terminal, the TPMI is used to indicate a precoder applied to the configured one SRS resource. When multiple SRS resources are configured for the terminal, the TPMI is used to indicate a precoder applied to an SRS resource indicated through the SRI.

[0147] The precoder used for PUSCH transmission is selected from an uplink codebook having the same number of antenna ports as the value of nrofSRS-Ports in the higher level signaling SRS-Config. In codebook-based PUSCH transmission, the terminal determines the codebook subset based on the TPMI and the codebookSubset in the higher level signaling pusch-Config. The codebookSubset in the higher level signaling pusch-Config is set to one of 'fullyAndPartialAndNonCoherent', 'partialAndNonCoherent', or 'nonCoherent' based on the UE capability reported by the terminal to the base station. If the terminal reports 'partialAndNonCoherent' in the UE capability, the terminal does not expect the value of the codebookSubset in the higher level signaling to be set to 'fullyAndPartialAndNonCoherent'. In addition, when the UE reports 'nonCoherent' in UE capability, the UE does not expect the value of codebookSubset, which is higher level signaling, to be set to 'fullyAndPartialAndNonCoherent' or 'partialAndNonCoherent'. When nrofSRS-Ports in SRS-ResourceSet, which is higher level signaling, indicates two SRS antenna ports, the UE does not expect the value of codebookSubset, which is higher level signaling, to be set to 'partialAndNonCoherent'.

[0148] The UE is configured with one SRS resource set in which the usage value in the SRS-ResourceSet, which is upper signaling, is set to 'codebook', and one SRS resource in the SRS resource set is indicated through the SRI. If multiple SRS resources are configured in an SRS resource set in which the usage value in the SRS-ResourceSet, which is upper signaling, is set to 'codebook', the UE expects that the value of nrofSRS-Ports in the SRS-Resource, which is upper signaling, is set to the same value for all SRS resources.

[0149] The terminal transmits one or more SRS resources included in the SRS resource set with the usage value set to 'codebook' to the base station through higher signaling, and the base station selects one of the SRS resources transmitted by the terminal and instructs the terminal to transmit a PUSCH using the transmission beam information of the SRS resource. In this case, in the codebook-based PUSCH transmission, the SRI is used as information for selecting an index of one SRS resource and is included in the DCI. In addition, the base station includes information indicating the TPMI and rank used by the terminal for PUSCH transmission in the DCI, and the terminal uses the SRS resource indicated by the SRI and performs PUSCH transmission by applying the indicated rank and the precoder indicated by the TPMI based on the transmission beam of the SRS resource.

[0150] Next, non-Codebook-based PUSCH transmission will be described. Non-Codebook-based PUSCH transmission is dynamically scheduled through DCI format 0_0 or 0_1, and operates semi-statically according to configured grant. If at least one SRS resource is configured in an SRS resource set in which the usage value in SRS-ResourceSet, which is higher-level signaling, is set to 'nonCodebook', the UE is scheduled for non-Codebook-based PUSCH transmission through DCI format 0_1.

[0151] For an SRS resource set in which the usage value in the higher level signaling SRS-ResourceSet is set to 'nonCodebook', the UE is configured with one connected NZP CSI-RS resource (non-zero power CSI-RS). The UE performs calculations for a precoder for SRS transmission through measurements on the NZP CSI-RS resource connected to the SRS resource set. If 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 aperiodic SRS transmission in the UE is less than 42 symbols, the UE does not expect the precoder information for SRS transmission to be updated.

[0152] When the value of resourceType in the SRS-ResourceSet, which is higher-level signaling, is set to 'aperiodic', the connected NZP CSI-RS is indicated in the SRS request field in DCI format 0_1 ​​or 1_1. At this time, if the connected NZP CSI-RS resource is an aperiodic NZP CSI-RS resource, if the value of the SRS request field in DCI format 0_1 ​​or 1_1 is not '00', it indicates that the connected NZP CSI-RS exists. At this time, the DCI should not indicate cross carrier or cross BWP scheduling. Also, if the value of the SRS request indicates the existence of the NZP CSI-RS, the NZP CSI-RS is located in the slot in which the PDCCH including the SRS request field is transmitted. At this time, the TCI state set in the scheduled subcarrier is not set to QCL-TypeD.

[0153] When a periodic or semi-persistent SRS resource set is configured, the connected NZP CSI-RS is indicated through the associated CSI-RS in the higher level signaling SRS-ResourceSet. For non-codebook-based transmission, the UE does not expect the higher level signaling spatialRelationInfo for the SRS resource and the associated CSI-RS in the higher level signaling SRS-ResourceSet to be configured together.

[0154] When multiple SRS resources are configured, the terminal determines the precoder and transmission rank to be applied to PUSCH transmission based on the SRI indicated by the base station. At this time, the SRI is indicated through the SRS resource indicator field in the DCI or is set through the srs-ResourceIndicator, which is higher-level signaling. As with the above-mentioned Codebook-based PUSCH transmission, when the terminal is provided with an SRI through DCI, the SRS resource indicated by the SRI means an SRS resource corresponding to the SRI in the SRS resource transmitted before the PDCCH including the SRI. The terminal uses one or multiple SRS resources for SRS transmission, and the maximum number of SRS resources that can be simultaneously transmitted with the same symbol in one SRS resource set and the maximum number of SRS resources are determined by the UE capability reported by the terminal to the base station. At this time, the SRS resources simultaneously transmitted by the terminal occupy the same RB. The terminal configures one SRS port for each SRS resource. Only one SRS resource set is configured with the usage value set to 'nonCodebook' in the higher level signaling SRS-ResourceSet, and up to four SRS resources for non-Codebook-based PUSCH transmission can be configured.

[0155] The base station transmits one NZP-CSI-RS connected to the SRS resource set to the terminal, and the terminal calculates a precoder to be used when transmitting one or more SRS resources in the SRS resource set based on the measurement result when receiving the NZP-CSI-RS. The terminal applies the calculated precoder when transmitting one or more SRS resources in the SRS resource set with usage set to 'nonCodebook' from the base station, and the base station selects one or more SRS resources from the received one or more SRS resources. In this case, in non-Codebook-based PUSCH transmission, the SRI indicates an index that can express a combination of one or more SRS resources, and the SRI is included in the DCI. In this case, the number of SRS resources indicated by the SRI transmitted by the base station is the number of PUSCH transmission layers, and the terminal transmits PUSCH by applying the precoder applied to SRS resource transmission to each layer.

[0156] FIG. 10 is a diagram illustrating radio protocol architectures of a base station and a terminal in single cell, carrier aggregation, and dual connectivity situations in a wireless communication system according to an embodiment.

[0157] Referring to Figure 10, the radio protocols of the next generation mobile communication system consist of NR SDAP (Service Data Adaptation Protocol S25, S70), NR PDCP (Packet Data Convergence Protocol S30, S65), NR RLC (Radio Link Control S35, S60), and NR MAC (Medium Access Control S40, S55) in the terminal and NR base station, respectively.

[0158] The main functions of the NR SDAP (S25, S70) include some of the following functions:

[0159] -Transfer of user plane data

[0160] -Mapping function between a QoS flow and a data bearer for uplink and downlink (mapping between a QoS flow and a DRB for both DL and UL)

[0161] - QoS flow ID marking function for uplink and downlink (marking QoS flow ID in both DL and UL packets)

[0162] - Ability to map reflective QoS flow to data bearers for uplink SDAP PDUs (reflective QoS flow to DRB mapping for the UL SDAP PDUs).

[0163] For the SDAP layer device, the terminal sets in the RRC message whether to use the header of the SDAP layer device for each PDCP layer device, bearer, or logical channel, or whether to use the function of the SDAP layer device. If the SDAP header is set, the NAS QoS reflection setting 1-bit indicator (NAS reflective QoS) and AS QoS reflection setting 1-bit indicator (AS reflective QoS) of the SDAP header indicate that the terminal can update or reset the mapping information for the uplink and downlink QoS flows and data bearers. The SDAP header includes QoS flow ID information indicating QoS. QoS information is used for data processing priority, scheduling information, etc. to support smooth services.

[0164] The main functions of the NR PDCP (S30, S65) include some of the following functions:

[0165] -Header compression and decompression function (ROHC only)

[0166] -Transfer of user data

[0167] -In-sequence delivery of upper layer PDUs

[0168] -Out-of-sequence delivery of upper layer PDUs

[0169] -Reordering function (PDCP PDU reordering for reception)

[0170] -Duplicate detection of lower layer SDUs

[0171] -Retransmission of PDCP SDUs

[0172] -Ciphering and deciphering function

[0173] -Timer-based SDU discard in uplink.

[0174] In the above, the reordering function of the NR PDCP device refers to a function of reordering PDCP PDUs received at a lower layer in order based on PDCP sequence number (SN) and includes a function of transmitting data to a higher layer in the reordered order. Alternatively, the reordering function of the NR PDCP device includes a function of immediately transmitting data without considering the sequence, a function of recording a dropped PDCP PDU by reordering the sequence, a function of reporting a status of a dropped PDCP PDU to a sender, and a function of requesting retransmission of a dropped PDCP PDU.

[0175] The main functions of NR RLC (S35, S60) include some of the following functions:

[0176] -Data transmission function (Transfer of upper layer PDUs)

[0177] -In-sequence delivery of upper layer PDUs

[0178] -Out-of-sequence delivery of upper layer PDUs

[0179] -ARQ function (Error Correction through ARQ)

[0180] -Concatenation, segmentation and reassembly of RLC SDUs

[0181] -Re-segmentation of RLC data PDUs

[0182] -Reordering of RLC data PDUs

[0183] -Duplicate detection

[0184] Protocol error detection

[0185] -RLC SDU deletion function (RLC SDU discard)

[0186] -RLC re-establishment function

[0187] In the above, the in-sequence delivery function of the NR RLC device means a function of delivering RLC SDUs received from a lower layer to a higher layer in sequence. The in-sequence delivery function of the NR RLC device includes a function of reassembling and delivering an RLC SDU when one RLC SDU is originally divided into multiple RLC SDUs and received, a function of reordering received RLC PDUs based on RLC SN (sequence number) or PDCP SN (sequence number), a function of recording missing RLC PDUs by rearranging the procedure, a function of reporting the status of missing RLC PDUs to the sender, and a function of requesting retransmission of missing RLC PDUs. The in-sequence delivery function of the NR RLC device includes a function of delivering only the RLC SDUs up to the missing RLC SDU to the upper layer in sequence when there is a missing RLC SDU, or a function of delivering all RLC SDUs received before the timer starts to the upper layer in sequence when a certain timer expires even if there is a missing RLC SDU. Alternatively, the in-sequence delivery function of the NR RLC device includes a function of delivering all RLC SDUs received up to now to the upper layer in sequence when a certain timer expires even if there is a missing RLC SDU. In addition, the RLC PDUs can be processed in the order in which they are received (in the order in which they arrive, regardless of the order of serial numbers and sequence numbers) and delivered to the PDCP device regardless of the order (out-of-sequence delivery), and in the case of a segment, a segment stored in a buffer or received later is received and reconstructed into a complete RLC PDU, and then processed and delivered to the PDCP device. The NR RLC layer may not include a concatenation function, and the function may be performed in the NR MAC layer or may be replaced by the multiplexing function of the NR MAC layer.

[0188] In the above, the out-of-sequence delivery function of the NR RLC device refers to a function of immediately delivering an RLC SDU received from a lower layer to a higher layer regardless of the procedure, and includes a function of reassembling and delivering an RLC SDU that was originally divided into multiple RLC SDUs and received, and a function of storing the RLC SN or PDCP SN of the received RLC PDU, aligning the procedure, and recording the missing RLC PDU.

[0189] The NR MAC (S40, S55) is connected to many NR RLC layer devices configured in one terminal, and the main functions of the NR MAC include some of the following functions.

[0190] -Mapping function (Mapping between logical channels and transport channels)

[0191] -Multiplexing / demultiplexing of MAC SDUs

[0192] -Scheduling information reporting function

[0193] -HARQ function (Error correction through HARQ)

[0194] -Priority handling between logical channels of one UE

[0195] -Priority handling between UEs by means of dynamic scheduling

[0196] -MBMS service identification function

[0197] -Transport format selection function

[0198] -Padding function

[0199] The NR PHY layer (S45, S50) performs channel coding and modulation of upper layer data, generates OFDM symbols and transmits them over a wireless channel, or demodulates and channel decodes the OFDM symbols received over a wireless channel and transmits them to a higher layer.

[0200] The detailed structure of the radio protocol structure varies according to the carrier (or cell) operation method. For example, when the base station transmits data to the terminal based on a single carrier (or cell), the base station and the terminal use a protocol structure having a single structure for each layer, such as S00. On the other hand, when the base station transmits data to the terminal based on carrier aggregation (CA) using multiple carriers in a single TRP, the base station and the terminal use a protocol structure having a single structure up to RLC, such as S10, but multiplexing the PHY layer through the MAC layer. As another example, when the base station transmits data to the terminal based on dual connectivity (DC) using multiple carriers in multiple TRP, the base station and the terminal use a protocol structure having a single structure up to RLC, such as S20, but multiplexing the PHY layer through the MAC layer.

[0201] Referring to the above description of PDCCH and beam setting, since the current Rel-15 and Rel-16NR do not support repeated transmission of PDCCH, it is difficult to achieve the required reliability in scenarios requiring high reliability such as URLLC. The present invention proposes a method for improving the PDCCH reception reliability of a terminal by providing a method for repeated transmission of PDCCH through multiple transmission points (TRPs). A specific method will be described in detail in the following embodiment.

[0202] The contents of the present invention can be applied to FDD and TDD systems. Hereinafter, in the present invention, higher signaling (or higher layer signaling) refers to a signaling method in which a base station transmits a signal to a terminal using a downlink data channel of a physical layer, or a terminal transmits a signal to a base station using an uplink data channel of a physical layer, and is also called RRC signaling, PDCP signaling, or MAC (medium access control) control element (MAC control element: MAC CE).

[0203] Hereinafter, in the present invention, when the terminal determines whether cooperative communication is applied, various methods can be used, such as whether the PDCCH to which the PDSCH to which cooperative communication is applied has a specific format, whether the PDCCH to which the PDSCH to which cooperative communication is applied includes a specific indicator indicating whether cooperative communication is applied, whether the PDCCH to which the PDSCH to which cooperative communication is applied is scrambled with a specific RNTI, or whether cooperative communication is assumed to be applied in a specific interval indicated by a higher layer. Hereinafter, for convenience of explanation, the case where the terminal receives a PDSCH to which cooperative communication is applied under similar conditions as above is referred to as an NC-JT case.

[0204] Hereinafter, in the present invention, determining the priority between A and B may be variously referred to as selecting the one with the higher priority according to a predetermined priority rule and performing an action corresponding thereto, or omitting or dropping an action corresponding to the one with the lower priority.

[0205] Hereinafter, the present invention will be described with reference to a number of embodiments, which are not independent and one or more embodiments can be applied simultaneously or in combination.

[0206] The base station is at least one of gNode B, gNB, eNode B, Node B, BS (Base Station), radio access unit, base station controller, or node on the network, which is a subject that allocates resources to the terminal. The terminal includes UE (User Equipment), MS (Mobile Station), cellular phone, smartphone, computer, or multimedia system that performs communication function. Hereinafter, the embodiment of the present invention will be described using the 5G system as an example, but the embodiment of the present invention can be applied to other communication systems having similar technical background or channel form. For example, LTE or LTE-A mobile communication and mobile communication technology developed after 5G are included here. Therefore, the embodiment of the present invention can be applied to other communication systems through some modifications within the scope of the present invention as judged by a person skilled in the art. The contents of the present invention can be applied to FDD and TDD systems.

[0207] In addition, in the description of the present invention, if it is determined that a detailed description of related functions or configurations may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. In addition, the terms described below are defined in consideration of the functions of the present invention, and may differ depending on the intentions and practices of users or operators. Therefore, the definitions should be based on the contents of this specification as a whole.

[0208] In the following description of the present invention, higher layer signaling refers to signaling that corresponds to at least one or a combination of one or more of the following signaling:

[0209] -MIB(Master Information Block)

[0210] -SIB (System Information Block) or SIB X (X = 1, 2, ...)

[0211] -RRC (Radio Resource Control)

[0212] -MAC(Medium Access Control)CE(Control Element)

[0213] Furthermore, the L1 signaling is signaling that corresponds to at least one or a combination of one or more of the signaling methods using the following physical layer channels or signaling:

[0214] -PDCCH (Physical Downlink Control Channel)

[0215] -DCI(Downlink Control Information)

[0216] -UE-specific DCI

[0217] -Group common DCI

[0218] -Common DCI

[0219] -Scheduling DCI (e.g., DCI used for scheduling downlink or uplink data)

[0220] -Non-scheduling DCI (e.g., DCI not intended to schedule downlink or uplink data)

[0221] -PUCCH (Physical Uplink Control Channel)

[0222] -UCI(Uplink Control Information)

[0223] Hereinafter, in the present invention, determining the priority between A and B may be variously referred to as selecting the one with the higher priority according to a predetermined priority rule and performing an action corresponding thereto, or omitting or dropping the action corresponding to the one with the lower priority.

[0224] Hereinafter, the present invention will be described by way of examples through a number of embodiments, which are not independent, and one or more embodiments can be applied simultaneously or in combination.

[0225] According to the 3GPP NR system, a terminal uses two PDSCH mapping types to determine the location of a DMRS for PDSCH reception. The two PDSCH mapping types are referred to as PDSCH mapping type A and PDSCH mapping type B for convenience.

[0226] According to PDSCH mapping type A, the first DMRS (first DMRS or front-loaded DMRS) of the PDSCH starts from the K-th symbol of the slot. Here, K is a value of 2 or 3, and is indicated by the PBCH (Physical Broadcast Channel). For reference, the symbol corresponding to K=0 (the 0th symbol) is the first symbol of the slot. In order for a terminal to receive a PDSCH of PDSCH mapping type A, the time domain of the PDSCH must include the K-th symbol. That is, the time domain allocation of the PDSCH of PDSCH mapping type A must have a start symbol (S) of 0, 1, 2, or 3, and a length (L) of 3, 4, ..., 14. Table 16 shows possible combinations of start symbol (S) and length (L) when PDSCH mapping type A is used.

[0227] According to PDSCH mapping type B, the first DMRS (or front-loaded DMRS) of the PDSCH is located at the first symbol of the scheduled PDSCH. Unlike PDSCH mapping type A, in PDSCH mapping type B, the position of the first DMRS is determined by the time resource allocation of the scheduled PDSCH. The time domain allocation of the PDSCH for PDSCH mapping type B has a start symbol (S) of one of 0, 1, ..., 12, and a length (L) of one of 2, 3, ..., 13. Table 16 shows the possible combinations of start symbol (S) and length (L) when PDSCH mapping type B is used.

[0228] [Table 16]

[0229] Here, the PDSCH mapping type has been described, but the PUSCH also uses two PUSCH mapping types (PUSCH mapping type A and PUSCH mapping type B). In the following description, for convenience, the PDSCH or PUSCH will be abbreviated to mapping type.

[0230] The terminal receives time domain information and an indication of the mapping type through a time domain resource assignment (TDRA) field of the DCI format.

[0231] The base station sets the TDRA table used by the DCI format in the terminal. The TDRA table has multiple rows. Each row includes at least the following information:

[0232] - TDRA row index -Time domain information contained in the TDRA line (S, L) -TDRA line mapping type -Slot offset value (K0 value) for receiving PDSCH or slot offset value (K2 value) for transmitting PUSCH according to time domain information of TDRA row

[0233] The UE receives the index of the TDRA row in the TDRA field of the DCI format, and thus obtains information on the time domain information, mapping type, etc. of the TDRA row corresponding to the index of the TDRA row.

[0234] Mapping type A and mapping type B have different use cases. For example, the first DMRS of the PDSCH (or PUSCH) of mapping type A always starts at the Kth symbol of a slot regardless of the time domain resource allocation of the PDSCH (or PUSCH). Therefore, even if different terminals are scheduled with PDSCH (or PUSCH) with different time domain resource allocation, the position of the first DMRS of the PDSCH (or PUSCH) is the same. Therefore, it may be suitable for multiplexing between different terminals, i.e., multi-user MIMO (MU-MIMO). In the case of mapping type B, when different terminals receive (transmit) PDSCH (or PUSCH) with different start positions, the first DMRS position of the PDSCH (or PUSCH) of different terminals is different. Since the DMRS is always located at the first symbol of the scheduled PDSCH (or PUSCH), the terminal receives the DMRS earliest and performs channel estimation or PDSCH decoding (the base station receives the DMRS earliest and performs channel estimation or PUSCH decoding). Therefore, mapping type B is suitable for an environment where high-speed PDSCH (or PUSCH) reception (transmission) and decoding are required. Therefore, different mapping types have different DMRS settings.

[0235] A terminal has a different DMRS setting for each mapping type.

[0236] The DMRS configuration includes at least the following three pieces of information:

[0237] -dmrs-Type: DMRS configuration type, set to either 1 or 2

[0238] -maxLength: Sets the maximum number of symbols that the DMRS can occupy.

[0239] -dmrs-AdditionalPosition: Sets an additional DMRS other than the first DMRS (first DMRS or front-loaded DMRS).

[0240] The three pieces of information in the DMRS setting are set differently for each mapping type. For example, 1 is set for dmrs-Type in the case of mapping type A, and 2 is set for dmrs-Type in the case of mapping type B. For example, 2 is set for maxLength in the case of mapping type A, and 1 is set for maxLength in the case of mapping type B. For example, dmrs-AdditionalPosition for mapping type A and dmrs-AdditionalPosition for mapping type B are different from each other.

[0241] The Antenna port field will now be described.

[0242] The terminal needs information on the DMRS port for PDSCH reception or PUSCH transmission. The information is indicated in the Antenna port field of the DCI format for scheduling the PDSCH or PUSCH.

[0243] The Antenna port field points to a row in the Antenna port table, where a row in the Antenna port table contains at least the following information:

[0244] -Index of the row in the Antenna port table - Index of the DMRS port(s) corresponding to the row in the Antenna port table - The number of DMRS symbols corresponding to the rows of the Antenna port table (present if maxLength is 2 or more) -Number of data or CDM (code division multiplexing) groups corresponding to the rows of the Antenna port table

[0245] A terminal receives a different DMRS configuration for each mapping type. For example, a first DMRS configuration is configured for mapping type A, and a second DMRS configuration is configured for mapping type B. Therefore, a first antenna port table for a PDSCH (or PUSCH) scheduled for mapping type A is different from a second antenna port table for a PDSCH (or PUSCH) scheduled for mapping type B. Furthermore, the two antenna port tables have a different number of rows. The two antenna port tables have different DMRS port(s) indexes, different numbers of DMRS symbols, or different data in the same row index, or the number of CDM groups, etc. are different.

[0246] The terminal receives an indication of a row of one of the two antenna port tables in the DCI format. More specifically, the terminal determines the length of the antenna port field in the DCI format based on the maximum number of rows in each of the two antenna port tables. For example, assume that the first antenna port table includes a total of 32 rows and the second antenna port table includes 64 rows. In this case, the terminal determines the length of the antenna port field based on the maximum value being 64. That is, it is determined as ceil(log2(64))=6 bits.

[0247] The terminal determines the mapping type of the PDSCH (or PUSCH) to be scheduled through the TDRA field of the DCI format. The terminal determines an antenna port table based on the DMRS setting of the mapping type. It also determines the number of required bits according to the determined number of rows in the antenna port table. The number of required bits is equal to or smaller than the number of bits of the antenna port. The terminal obtains an index of a row in the antenna port table from some bits (e.g., LSB, least significant bits) of the number of required bits in the antenna port field. Through a series of processes, the terminal obtains the mapping type of the PDSCH (or PUSCH) to be scheduled and DMRS-related information (index of DMRS port(s), number of DMRS symbols, number of data or CDM groups, etc.).

[0248] For reference, in the case of PUSCH, the antenna port table is determined according to the DMRS setting of the mapping type of the scheduled PUSCH and the rank of the PUSCH.

[0249] Table 17 shows the antenna port field of DCI format 0_1 ​​for PUSCH scheduling, and Tables 18 to 37 are corresponding antenna port tables.

[0250] [Table 17] TIFF2025511982000031.tif50170

[0251] [Table 18]

[0252] [Table 19]

[0253]

Table 20

[0254]

Table 21

[0255]

Table 22

[0256]

Table 23

[0257]

Table 24

[0258]

Table 25

[0259]

Table 26

[0260]

Table 27

[0261]

Table 28

[0262]

Table 29

[0263] [Table 30]

[0264] [Table 31]

[0265] [Table 32]

[0266] [Table 33]

[0267] [Table 34]

[0268] [Table 35]

[0269] [Table 36]

[0270] [Table 37]

[0271] Table 38 shows the Antenna port field of DCI format 1_1 for scheduling the PDSCH, and Tables 39 to 46 are the corresponding Antenna port tables.

[0272] [Table 38]

[0273]

Table 39

[0274]

Table 40

[0275]

Table 41

[0276]

Table 42

[0277]

Table 43

[0278]

Table 44

[0279]

Table 45

[0280]

Table 46

[0281] It is assumed that dmrs-Type=1 and maxLength=2 are set in the DMRS configuration for one of the PDSCH mapping types of the terminal. In this case, the corresponding antenna port table is shown in Table 42. The terminal receives a DCI format for scheduling a PDSCH that is a PDSCH mapping type, and the DCI format includes an antenna port field. The antenna port field indicates one of the 32 rows (value 0 to value 31) of Table 42. For reference, referring to Table 42, when only one codeword of the PDSCH is activated, one of all 32 rows (value 0 to value 31) is indicated. When two codewords are simultaneously activated in the PDSCH, one of four rows (value 0 to value 3) out of the 32 rows is indicated. And the other rows (value 3 to value 31) are not indicated.

[0282] It is assumed that dmrs-Type = 2 and maxLength = 2 are set in the DMRS configuration for one of the PUSCH mapping types of the terminal. In this case, the corresponding antenna port table is one of Tables 34 to 37. Here, one antenna port table is determined by rank. It is assumed that rank = 3. In this case, Table 36 is used as the antenna port table. The terminal receives a DCI format for scheduling a PUSCH that is a PUSCH mapping type, and the DCI format includes an antenna port field. The antenna port field indicates one of the 32 rows (value 0 to value 31) of Table 36. For reference, referring to Table 36, one of six rows (value 0 to value 5) out of the 32 rows is indicated. And the other rows (value 6 to value 31) are not indicated.

[0283] In the following embodiments, the terminal includes multiple pieces of scheduling information of at least one TDRA row in the TDRA table, and one piece of the multiple pieces of scheduling information of the TDRA row includes mapping type A, and the other piece of scheduling information includes both mapping type B. That is, when the terminal receives an indication of a TDRA row, it receives (or transmits) a PDSCH (or PUSCH) with mapping type A according to one piece of scheduling information, and receives (or transmits) a PDSCH (or PUSCH) with mapping type B according to the other piece of scheduling information.

[0284] In the following embodiments, for convenience of explanation, “TDRA rows of different mapping types” means that a TDRA row includes multiple scheduling information, one of which includes mapping type A and the other of which includes both mapping type B.

[0285] The procedure for using uplink PTRS is described.

[0286] The terminal sets phaseTrackingRS, which is an upper layer parameter for PTRS, on the upper layer parameter DMRS-UplinkConfig. When the terminal transmits a PUSCH at the base station, the terminal transmits a phase tracking reference signal (PTRS) for phase tracking of an uplink channel. The procedure for transmitting UL PTRS by the terminal is determined depending on whether or not to perform transform precoding when transmitting a PUSCH. When transform precoding is performed and the transformPrecoderEnabled field is set in the upper layer parameter PTRS-UplinkConfig, the sampleDensity in the transformPrecoderEnabled field indicates the sample density threshold shown in NRB0 to NRB4 in Table 47. When transform precoding is performed and the transformPrecoderEnabled field is set in the upper layer parameter PTRS-UplinkConfig, the terminal determines a PT-RS group pattern for the scheduled resource NRB according to Table 47. Additionally, when transform precoder is applied to PUSCH transmission, the number of bits in the PTRS-DMRS association field for indicating the association between the PTRS and the DMRS in DCI format 0_1 ​​or 0_2 is 0.

[0287] [Table 47]

[0288] If transform precoding is not applied to PUSCH transmission and the upper layer parameter phaseTrackingRS is set, the terminal indicates NRB0 or ​​NRB1 of frequencyDensity in the transformPrecoderDisabled field in the upper layer parameter PTRS-UplinkConfig and indicates ptrs-MCS1 to ptrs-MCS3 of timeDensity. The terminal determines the PT-RS density in the time domain (LPT-RS) and the PT-RS density in the frequency domain (KPT-RS) as described in Tables 48-1 and 48-2 according to the MCS (lMCS) and RB (NRB) of the scheduled PUSCH. In Table 48-1, ptrs-MCS4 is not specified in the upper layer parameters, but the base station and the terminal know that it is 29 or 28 according to the configured MCS table.

[0289] [Table 48-1]

[0290] [Table 48-2]

[0291] When Transform precoder is not applied to PUSCH transmission and PTRS-UplinkConfig is set, the base station indicates to the terminal a 2-bit 'PTRS-DMRS association' field to indicate an association between the PTRS and the DMRS in DCI format 0_1 ​​or 0_2. The indicated 2-bit PTRS-DMRS association field is applied to Table 49-1 or Table 49-2 depending on the maximum number of ports of the PTRS set in maxNrofPorts in the upper layer parameter PTRS-UplinkConfig. When the maximum PTRS port value is 1, the terminal determines the association between the PTRS and the DMRS using Table 49-1 and the 2 bits indicated in the PTRS-DMRS association field, and transmits the PTRS according to the determined association. When the maximum PTRS port value is 2, the terminal determines the association between the PTRS and the DMRS using Table 49-2 and the 2 bits indicated in the PTRS-DMRS association field, and transmits the PTRS according to the determined association.

[0292] [Table 49-1]

[0293] [Table 49-2]

[0294] The DMRS ports in Tables 49-1 and 49-2 are determined through the 'Antenna ports' field indicated in the same DCI as the DCI indicating the PTRS-DMRS association and a table determined by the upper layer parameter configuration. If transform precoder is not set in the upper configuration of the PUSCH, dmrs-Type is set to 1 and maxLength is set to 2 for DMRS, and the rank of the PUSCH is 2, the UE determines the DMRS port through the table for 'Antenna port(s)' as shown in Table 50 and the bits indicated in the Antenna ports field. If non-Codebook-based PUSCH is supported, the UE determines the value of rank by referring to the SRI field indicated in the same DCI as the DCI including the 'Antenna ports' field (i.e., if the SRI field does not exist, the Rank is considered to be 1). If rank supports codebook-based PUSCH, the UE determines the value of rank by referring to the TPMI field indicated in the same DCI as the DCI including the 'Antenna ports' field. Table 50 is an example of an Antenna port table to be referenced when configuring the PUSCH described above, and is not limited thereto. If the PUSCH is configured with other parameters, the DMRS port is determined by the configured 'Antenna port' table and the bit in the 'Antenna ports' field indicated in the DCI.

[0295] [Table 50]

[0296] The 1st scheduled DMRS to 4th scheduled DMRS in Table 49-1 are defined as values ​​obtained by sequentially mapping the bits in the 'Antenna ports' field of DCI and the DMRS ports indicated in the 'antenna port' table by the higher layer configuration. For example, if the bits in the 'Antenna ports' field of DCI are 0001 and the DMRS ports are determined by referring to Table 50, the scheduled DMRS ports are 0 and 1, and DMRS port 0 is defined as the 1st scheduled DMRS and DMRS port 1 is defined as the 2nd scheduled DMRS. The same applies to DMRS ports determined in the 'antenna port' table by the higher layer configuration that differ from the bits in the 'Antenna ports' field. The UE determines one DMRS port to associate with the PTRS port by referring to the bit indicated in the PTRS-DMRS association in DCI among the DMRS ports defined as above, and transmits the PTRS through the determined DMRS port.

[0297] In Table 49-2, the DMRS ports sharing PTRS port 0 and the DMRS ports sharing PTRS port 1 are defined according to codebook-based PUSCH transmission or non-codebook-based PUSCH transmission. When the terminal transmits PUSCH on a partial-coherent or non-coherent codebook basis, the uplink layer transmitted to PUSCH antenna ports 1000 and 1002 is associated with PTRS port 0, and the uplink layer transmitted to PUSCH antenna ports 1001 and 1003 is associated with PTRS port 1. More specifically, when layer 3:TPMI=2 is selected for codebook-based PUSCH transmission, the first layer is associated with PTRS port 0 since it is transmitted to PUSCH antenna ports 1000 and 1002, the second layer is transmitted to PUSCH antenna port 1001, and the third layer is transmitted to PUSCH antenna port 1002, and the second and third layers are associated with PTRS port 1. The three layers refer to the respective DMRS ports. The DMRS port for the first layer corresponds to '1st DMRS port which shares PTRS port 0' in Table 49-2, the DMRS port for the second layer corresponds to '1st DMRS port which shares PTRS port 1' in Table 49-2, and the DMRS port for the third layer corresponds to '2nd DMRS port which shares PTRS port 1' in Table 49-2. Similarly, the DMRS port associated with PTRS port 0 and the DMRS port associated with PTRS port 1 are determined by different layer numbers and TPMI. When the terminal transmits PUSCH on a non-Codebook basis, the DMRS port associated with PTRS port 0 and the DMRS port associated with PTRS port 1 are distinguished according to the SRI and antenna ports indicated in the DCI.More specifically, whether an SRS resource included in an SRS resource set with usage 'nonCodebook' is associated with PTRS port 0 or PTRS port 1 is set through the upper layer parameter ptrs-PortIndex. The base station indicates an SRS resource for transmitting a non-Codebook based PUSCH in the SRI. The port of each indicated SRS resource is mapped one-to-one with each PUSCH DMRS port. The association relationship between the PUSCH DMRS port and the PTRS port is determined by the upper layer parameter ptrs-PortIndex of the SRS resource mapped to the DMRS port. More specifically, when ptrs-PortIndex is set to n0, n0, n1, n1 for SRS resources 1 to 4 included in an SRS resource set with usage nonCodebook, and the SRI indicates that PUSCH is to be transmitted through SRS resources 1, 2, and 4, and DMRS ports 0, 1, and 2 are indicated in the Antenna ports field, the ports of each SRS resource 1, 2, and 4 are mapped to DMRS ports 0, 1, and 2. And DMRS ports 0 and 1 are associated with PTRS port 0, and DMRS port 2 is associated with PTRS port 1 according to the ptrs-PortIndex in the SRS resource. Therefore, in Table 49-2, DMRS port 0 corresponds to '1st DMRS port which shares PTRS port0', DMRS port 1 corresponds to '2nd DMRS port which shares PTRS port 0', and DMRS port 2 corresponds to '1st DMRS port which shares PTRS port1'. Similarly, the DMRS port associated with PTRS port 0 and the DMRS port associated with PTRS port 1 are determined by the ptrs-PortIndex setting method and other SRI values ​​in the SRS resource of different patterns. The terminal determines the association relationship between the DMRS port and the PTRS port for the two PTRS ports as described above.The terminal determines the DMRS port associated with PTRS port 0 by referring to the MSB bit of the PTRS-DMRS association among multiple DMRS ports associated with each PTRS port. The terminal determines the DMRS port associated with PTRS port 1 by referring to the LSB bit and transmits the PTRS.

[0298] [Multi-PDSCH / PUSCH Scheduling]

[0299] A new scheduling method has been introduced in Rel-17 NR (new raido) of 3GPP (registered trademark). The present invention relates to the new scheduling method. The new scheduling method introduced in Rel-17NR is 'Multi-PDSCH scheduling' in which one DCI schedules one or more PDSCHs, and 'Multi-PUSCH scheduling' in which one DCI schedules one or more PUSCHs. Here, in multiple PDSCHs or multiple PUSCHs, each PDSCH or each PUSCH transmits a different transport block (TB). By using Multi-PDSCH scheduling and Multi-PUSCH scheduling, the base station does not schedule multiple DCIs that schedule multiple PDSCHs or multiple PUSCHs to the terminal, so that the overhead of the downlink control channel can be reduced. However, one DCI for Multi-PDSCH scheduling and Multi-PUSCH scheduling must include scheduling information for multiple PDSCHs or multiple PUSCHs, so the size of the DCI increases. For this reason, when Multi-PDSCH scheduling and Multi-PUSCH scheduling are configured in a terminal, a method for the terminal to favorably interpret DCI is required.

[0300] Although the present specification describes Multi-PDSCH scheduling, the concept of the technology proposed in the present invention can be used in Multi-PUSCH scheduling.

[0301] The base station configures the terminal with multi-PDSCH scheduling. The base station explicitly configures the terminal with multi-PDSCH scheduling by using a higher layer signal (e.g., a radio resource control (RRC) signal). The base station also implicitly configures the terminal with multi-PDSCH scheduling by using a higher layer signal (e.g., an RRC signal).

[0302] The base station configures a time domain resource assignment (TDRA) table for multi-PDSCH scheduling in the terminal by a higher layer signal (e.g., an RRC signal) as follows. The TDRA table includes one or more rows. Up to a maximum of N_rows of rows are configured, and each row is assigned a unique index. The unique index is one value among 1, 2, ..., N_row. Here, N_row is preferably 64, but is not limited thereto. One or more pieces of scheduling information are configured in each row. Here, when one scheduling information is configured in one row, the row schedules one PDSCH. That is, when a row is indicated, it means that single-PDSCH scheduling is indicated. When multiple pieces of scheduling information are configured in one row, the multiple scheduling information schedule multiple PDSCHs in sequence. That is, when a row is indicated, it means that multi-PDSCH scheduling is indicated.

[0303] The scheduling information includes at least one of K0, SLIV, and PDSCH mapping type. That is, when Multi-PDSCH scheduling is indicated, a row includes multiple scheduling information (K0, SLIV, PDSCH mapping type). Among them, the N-th scheduling information (K0, SLIV, PDSCH mapping type) is the scheduling information of the N-th PDSCH. For reference, one row includes up to N_pdsch pieces of scheduling information (K0, SLIV, PDSCH mapping type). Here, N_pdsch=8 is preferably, but not limited to, N. For example, one row schedules up to 8 PDSCHs.

[0304] Here, K0 indicates the slot in which the PDSCH is scheduled, and thus indicates the slot difference between the slot in which the PDCCH, which transmits the DCI for scheduling the PDSCH, is received and the slot in which the PDSCH is scheduled. That is, when K0=0, the PDSCH and the PDCCH are the same slot. SLIV (starting and length indicator value) indicates the index of the symbol in which the PDSCH starts in one slot and the number of consecutive symbols to which the PDSCH is assigned. The PDSCH mapping type indicates information on the position of the first DMRS (front-loaded DMRS) of the PDSCH. In the case of PDSCH mapping type A, the first DMRS (front-loaded DMRS) of the PDSCH starts at the third or fourth symbol of the slot, and in the case of PDSCH mapping type B, the first DMRS (front-loaded DMRS) of the PDSCH starts from the first symbol in which the PDSCH is scheduled.

[0305] When a row of the TDRA table is set by a higher layer signal, some of the scheduling information, K0, SLIV, and PDSCH mapping type, are omitted. In this case, the omitted information is interpreted as a default value or a pre-defined value. For example, if K0 is omitted, the value of K0 is interpreted as 0. Also, when a row of the TDRA table is set, information other than K0, SLIV, and PDSCH mapping type is additionally set.

[0306] In the following description, the terminal is configured with multi-PDSCH scheduling. Here, the multi-PDSCH scheduling configuration means that multiple pieces of scheduling information are configured in at least one row of the TDRA table. For reference, one other row of the TDRA table is configured with one piece of scheduling information. Therefore, even if the multi-PDSCH scheduling is configured in the terminal, the terminal is instructed to perform single-PDSCH scheduling or multi-PDSCH scheduling according to the TDRA field of the received DCI. In other words, the multi-PDSCH scheduling indication is a case where the row of the TDRA table instructed by the terminal from the DCI includes multiple pieces of scheduling information, and the single-PDSCH scheduling indication is a case where the row of the TDRA table instructed by the terminal from the DCI includes one piece of scheduling information.

[0307] In the case of a single-PDSCH scheduling instruction, one PDSCH is scheduled, and one PDSCH requires information such as MCS (modulation coding scheme), NDI (new data indicator), RV (redundancy version), and HPN (HARQ process number). For this purpose, the DCI instructing the scheduling of the single-PDSCH must include information such as MCS, NDI, RV, and HPN for one PDSCH. More specifically,

[0308] - DCI scheduling and indicating a single-PDSCH includes one MCS field. The MCS (i.e., the modulation scheme and the code rate of the channel code) indicated in the MCS field is applied to one PDSCH scheduled by the DCI.

[0309] The DCI for scheduling the single-PDSCH includes a 1-bit NDI field. An NDI value is obtained from the 1-bit NDI field, and it is determined whether the single PDSCH transmits a new transmission block or retransmits a previous transmission block based on the NDI value.

[0310] -The DCI for scheduling the single-PDSCH includes a 2-bit RV field. The RV value is obtained from the 2-bit RV field, and the redundancy version of one PDSCH is determined based on the RV value.

[0311] -The DCI for scheduling the single-PDSCH includes one HPN field. One HPN field is 4 bits (for reference, if the terminal supports up to 32 HARQ processes, the HPN field is extended to 5 bits, but is assumed to be 4 bits for convenience of explanation of the present invention). One HARQ process ID is indicated through one HPN field. One HARQ process ID is the HARQ process ID of one scheduled PDSCH.

[0312] When instructing multi-PDSCH scheduling, multiple PDSCHs are scheduled, and therefore each PDSCH requires information such as MCS, NDI, RV, and HPN. To this end, the DCI instructing multi-PDSCH scheduling must include information such as MCS, NDI, RV, and HPN for each PDSCH to be scheduled. More specifically,

[0313] -The DCI indicating multi-PDSCH scheduling includes one MCS field. The MCS (i.e., the modulation scheme and the code rate of the channel code) indicated in the MCS field is applied to all PDSCHs scheduled by the DCI in the same manner. That is, the multi-PDSCH scheduling DCI does not schedule different PDSCHs using different MCSs.

[0314] -The DCI indicating multi-PDSCH scheduling includes a K-bit NDI field, where K is the maximum value of the number of scheduling information included in each row of the TDRA table. For example, when the TDRA table includes two rows, the first row includes four pieces of scheduling information, and the second row includes eight pieces of scheduling information, K=8. The k-th bit of the K-bit NDI field indicates the NDI value of the PDSCH corresponding to the k-th scheduling information. That is, the k-th PDSCH obtains the NDI value from the k-th bit of the K-bit NDI field, and determines whether the k-th PDSCH transmits a new transmission block or retransmits a previous transmission block based on the NDI value.

[0315] -The DCI indicating multi-PDSCH scheduling includes a K-bit RV field. The k-th bit of the K-bit RV field indicates the RV value of the PDSCH corresponding to the k-th scheduling information. That is, the k-th PDSCH obtains the RV value from the k-th bit of the K-bit RV field and determines the redundancy version of the k-th PDSCH based on the RV value.

[0316] - DCI indicating Multi-PDSCH scheduling includes one HPN field. One HPN field is 4 bits (for reference, if the terminal supports up to 32 HARQ processes, the HPN field is extended to 5 bits, but in the embodiment of the present invention, it is assumed to be 4 bits for convenience of explanation). One HARQ process ID is indicated through one HPN field. One HARQ process ID is the HARQ process ID of the first PDSCH among the PDSCHs scheduled by the DCI indicating Multi-PDSCH scheduling. Here, the first PDSCH corresponds to the first scheduling information. And, the HPN of the subsequent PDSCHs is sequentially increased by 1. That is, in the case of the second PDSCH (corresponding to the second scheduling information), the HPN is the HARQ process ID of the first PDSCH increased by 1. For reference, if the HARQ process ID exceeds the maximum number of HARQ process IDs (numOfHARQProcessID) set in the terminal, a modulo operation is performed. In other words, when the HARQ process ID indicated by the DCI is 'x', the HARQ process ID of the k-th PDSCH is determined as follows.

[0317] HPN of k-th PDSCH = (x + k - 1) modulo numOfHARQProcessID

[0318] As described above, when indicating single-PDSCH scheduling, the DCI includes a 1-bit NDI field or a 2-bit RV field, and when indicating multi-PDSCH scheduling, the DCI includes a K-bit NDI field or a K-bit RV field. For reference, the single-PDSCH scheduling indication or the multi-PDSCH scheduling indication is indicated in the TDRA field of the DCI (i.e., whether it is a single-PDSCH scheduling indication or a multi-PDSCH scheduling indication is determined according to the number of scheduling information included in the row of the indicated TDRA field). Therefore, one DCI must support both single-PDSCH scheduling and multi-PDSCH scheduling. If the length of the DCI for the single-PDSCH scheduling indication and the length of the DCI for the multi-PDSCH scheduling indication are different, '0' is added (padding) to the DCI of the shorter length to make them the same length.

[0319] The terminal interprets DCI as follows. The terminal receives DCI. In this case, the length of DCI is assumed to be the larger of the length of DCI for single-PDSCH scheduling indication and the length of DCI for multi-PDSCH scheduling indication. The terminal knows the position of the TDRA field in the DCI. The position of the TDRA field is the same for DCI for single-PDSCH scheduling indication and DCI for multi-PDSCH scheduling indication. The terminal determines whether the received DCI is a DCI for single-PDSCH scheduling indication or a DCI for multi-PDSCH scheduling indication through the TDRA field. If the number of pieces of scheduling information included in the row of the indicated TDRA field is one, the terminal determines it as a single-PDSCH scheduling indication, and if the number of pieces of scheduling information included in the row of the TDRA field is two or more, the terminal determines it as a multi-PDSCH scheduling indication. If the terminal determines it as a single-PDSCH scheduling indication, it interprets the DCI according to the determination. That is, the NDI field is interpreted as 1 bit and the RV field is interpreted as 2 bits. If the terminal determines that the DCI is a multi-PDSCH scheduling indication, it interprets the DCI according to the determination. That is, the NDI field is interpreted as K bits and the RV field is interpreted as K bits. For reference, the position of other fields in the DCI changes depending on the length of the NDI field or the RV field. Therefore, the bit length of other fields is the same depending on whether it is a single-PDSCH scheduling indication or a multi-PDSCH scheduling indication, but the position in the DCI is different.

[0320] FIG. 11 illustrates a PDSCH scheduling scheme according to one embodiment.

[0321] - The first row (row 0) of the TDRA table includes four pieces of scheduling information (K0, SLIV, PDSCH mapping type). Here, the first SLIV is SLIV00, the second SLIV is SLIV01, the third SLIV is SLIV02, and the fourth SLIV is SLIV03. Therefore, when the terminal receives an indication of the first row (row 0) of the TDRA table, it determines that Multi-PDSCH scheduling has been indicated.

[0322] The second row (row 1) of the TDRA table includes two pieces of scheduling information (K0, SLIV, PDSCH mapping type). Here, the first SLIV is SLIV10 and the second SLIV is SLIV11. Therefore, when the terminal receives an indication of the second row (row 1) of the TDRA table, it determines that multi-PDSCH scheduling has been indicated.

[0323] The third row (row 2) of the TDRA table includes one piece of scheduling information (K0, SLIV, PDSCH mapping type). Here, SLIV is SLIV20. Therefore, when the terminal receives an indication of the third row (row 2) of the TDRA table, it determines that Single-PDSCH scheduling has been indicated.

[0324] FIG. 11(a) shows a case where the terminal receives an indication of the first row (row 0) of the TDRA table. The TDRA field of the DCI received by the terminal on the PDCCH 1100 indicates the first row (row 0) of the TDRA table. As a result, the terminal receives four PDSCHs based on the four pieces of scheduling information (K0, SLIV, PDSCH mapping type) in the first row (row 0). The terminal determines the symbol for receiving the first PDSCH 1101 based on the first SLIV SLIV00, determines the symbol for receiving the second PDSCH 1102 based on the second SLIV SLIV01, determines the symbol for receiving the third PDSCH 1102 based on the third SLIV SLIV02, and determines the symbol for receiving the fourth PDSCH 1103 based on the fourth SLIV SLIV03. Each of the four PDSCHs has a unique HARQ process ID. That is, the first PDSCH has HPN0 as HARQ process ID, the second PDSCH has HPN1 as HARQ process ID, the third PDSCH has HPN2 as HARQ process ID, and the fourth PDSCH has HPN3 as HARQ process ID. Here, the HPN field of the DCI indicates the HARQ process ID of the first PDSCH, and the HARQ process IDs of the remaining PDSCHs are determined based on the HARQ process ID of the first PDSCH. For example, the DCI indicates HPN0=0 as the HARQ process ID of the first PDSCH. In this case, the HARQ process ID of the second PDSCH is HPN1=1, the HARQ process ID of the third PDSCH is HPN1=2, and the HARQ process ID of the fourth PDSCH is HPN1=3.

[0325] FIG. 11(b) shows a case where the terminal receives an instruction for the second row (row 1) of the TDRA table. The TDRA field of the DCI received by the terminal on the PDCCH 1110 indicates the second row (row 1) of the TDRA table. As a result, the terminal receives two PDSCHs based on the two pieces of scheduling information (K0, SLIV, PDSCH mapping type) in the second row (row 1). The terminal determines the symbol for receiving the first PDSCH 1111 based on the first SLIV, SLIV10, and determines the symbol for receiving the second PDSCH 1112 based on the second SLIV, SLIV11. Each of the two PDSCHs has a unique HARQ process ID. That is, the first PDSCH has HPN0 as the HARQ process ID, and the second PDSCH has HPN1 as the HARQ process ID. Here, the HFN field of the DCI indicates the HARQ process ID of the first PDSCH, and the HARQ process IDs of the remaining PDSCHs are determined based on the HARQ process ID of the first PDSCH. For example, the HARQ process ID of the first PDSCH in the DCI indicates HPN0=0. In this case, the HARQ process ID of the second PDSCH is HPN1=1.

[0326] FIG. 11(c) shows a case where the terminal receives an instruction for the third row (row 2) of the TDRA table. The TDRA field of the DCI received by the terminal on the PDCCH 1120 indicates the third row (row 2) of the TDRA table. As a result, the terminal receives one PDSCH based on one scheduling information (K0, SLIV, PDSCH mapping type) in the third row (row 2). The terminal determines the symbol for receiving one PDSCH 1121 based on one SLIV, SLIV20. The HARQ process ID of one PDSCH, i.e., HPN0, is indicated by the DCI. For example, the HPN field of the DCI indicates HPN0=0 for the HARQ process ID of the first PDSCH.

[0327] FIG. 12 is a diagram illustrating DCI for Single-PDSCH scheduling and Multi-PDSCH scheduling according to one embodiment.

[0328] 12(a) and 12(b), the terminal determines the position of the TDRA field 1200 in the received DCI. The position is the same for the Single-PDSCH scheduling DCI and the Multi-PDSCH scheduling DCI. The terminal determines whether the received DCI is a DCI indicating Single-PDSCH scheduling or a DCI indicating Multi-PDSCH scheduling based on the value of the TDRA field.

[0329] If the row corresponding to the value of the TDRA field of the received DCI contains one scheduling information (K0, SLIV, PDSCH mapping type) (e.g., the third row (row 2) of the TDRA table), the terminal interprets it as DCI for Single-PDSCH scheduling as shown in (a) of Figure 12.

[0330] 12(a), the DCI for Single-PDSCH scheduling includes a 5-bit MCS field 1205, a 1-bit NDI field 1210, a 2-bit RV field 1215, and a 4-bit HARQ field 1220. The DCI for Single-PDSCH scheduling further includes fields other than the above-mentioned fields. For example, the DCI further includes an Antenna port(s) field 1225 or a DMRS sequence initialization field 1230. If the DCI for Single-PDSCH scheduling is shorter than the DCI for Multi-PDSCH scheduling, it further includes padding bits 1235.

[0331] When a row corresponding to the value of the TDRA field of the received DCI includes two or more pieces of scheduling information (K0, SLIV, PDSCH mapping type) (for example, the first row (row 0) to the third row (row 1) of the TDRA table), the terminal interprets the DCI as a multi-PDSCH scheduling DCI as shown in FIG. 12(b). Referring to FIG. 12(b), the multi-PDSCH scheduling DCI includes a 5-bit MCS field 1255, a K-bit NDI field (1260, 1261), a K-bit RV field (1262, 1263), and a 4-bit HARQ field 1270. In addition, the multi-PDSCH scheduling DCI further includes fields other than the above-mentioned fields. For example, the DCI further includes an antenna port(s) field 1275 or a DMRS sequence initialization field 1280. For reference, FIG. 12(b) shows a DCI in which up to two PDSCHs are scheduled. Here, the 2-bit NDI fields (1260, 1261) are shown separately, but may be combined into one 2-bit field. Also, the 2-bit RV fields (1262, 1263) are shown separately from FIG. 12(b), but may be combined into one 2-bit field.

[0332] For reference, referring to Figure 12(a) or 12(b), padding bits 1235 are added to the DCI for single-PDSCH scheduling, assuming that the length of the DCI indicating single-PDSCH scheduling is shorter than the length of the DCI indicating multi-PDSCH scheduling. If the length of the DCI indicating single-PDSCH scheduling is longer than the length of the DCI indicating multi-PDSCH scheduling, padding bits are added to the DCI indicating multi-PDSCH scheduling.

[0333] Hereinafter, unless otherwise specified, this specification assumes that the PDSCH is a single codeword transmission. When two codeword transmissions are configured in the terminal, the DCI field is for the first codeword unless otherwise specified.

[0334] FIG. 13 is a diagram illustrating HARQ-ACK transmission of one or more PDSCHs scheduled by DCI when DCI indicates Multi-PDSCH scheduling according to one embodiment.

[0335] The base station configures one or more K1 values ​​in the terminal, which are called the K1 set. The DCI indicating Multi-PDSCH scheduling includes an indicator indicating one K1 value in the K1 set. More specifically, the DCI includes a PDSCH-to-HARQ_feedback timing indicator field of up to 3 bits. The field indicates one K1 value in the K1 set.

[0336] The terminal determines a slot for transmitting HARQ-ACKs of the multiple PDSCHs based on a K1 value and a slot in which the last PDSCH of the multiple PDSCHs is scheduled. For reference, HARQ-ACKs of all PDSCHs scheduled in one DCI are transmitted through one PUCCH in a slot for transmitting HARQ-ACKs. The slot located K1 slots after the slot in which the last PDSCH is scheduled is the slot for transmitting HARQ-ACKs of the multiple PDSCHs. That is, the PUCCH including the HARQ-ACKs of the multiple PDSCHs is transmitted in a slot K1 slots after the slot in which the last PDSCH is scheduled.

[0337] 13, it is assumed that the DCI received by the terminal through the PDCCH 1300 is indicated by row 0 of the TDRA table as shown in FIG. 12, and that the PDSCH is scheduled in slot n-5, slot n-4, slot n-3, and slot n-2 according to row 0 of the TDRA table. It is also assumed that the K1 value is 2. In this case, the terminal determines that the slot n after the two slots of the K1 value from slot n-2, which is the last slot in which the PDSCH is scheduled, is the slot for transmitting the HARQ-ACK. That is, the terminal transmits HARQ-ACK information of the PDSCH 1301 of slot n-5, the PDSCH 1302 of slot n-4, the PDSCH 1303 of slot n-3, and the PDSCH 1304 of slot n-2 in the PUCCH 1305 of slot n.

[0338] Multi-cell multi-PDSCH / PUSCH scheduling will be explained.

[0339] A new scheduling method has been introduced in Rel-18 NR (new raido) of 3GPP (registered trademark) (3rd generation partnership project). In the above-mentioned Multi-PDSCH / PUSCH scheduling, one DCI schedules one or more PDSCHs or PUSCHs in one cell. In the new scheduling method of Rel-18NR, one DCI schedules PDSCHs or PUSCHs in each of multiple cells. This scheduling method is called multi-cell multi-PDSCH / PUSCH scheduling.

[0340] The terminal receives an indication of a cell in which a PDSCH or a PUSCH is scheduled through one DCI. For example, one DCI indicates Cell A and Cell B. The terminal also receives an indication of scheduling information of Cell A (K0 / SLIV / PDSCH mapping type for PDSCH, and K2 / SLIV / PUSCH mapping type for PUSCH) and scheduling information of Cell B. The terminal receives a PDSCH or transmits a PUSCH based on the scheduling information indicated by Cell A and Cell B.

[0341] Here, a different mapping type is indicated in the scheduling information of each cell.

[0342] Hereinafter, the present invention will be described based on multi-PDSCH / PUSCH scheduling, but the present invention can be applied to multi-cell multi-PDSCH / PUSCH scheduling.

[0343] In the following description of the present invention, a problem will be described in which multiple PDSCHs or PUSCHs in multi-PDSCH / PUSCH scheduling have different mapping types and different antenna port tables are applied to each mapping type. In multi-cell multi-PDSCH / PUSCH scheduling, PDSCHs or PUSCHs of the same multiple cells have different mapping types. Therefore, a problem occurs in which different antenna port tables are applied to each mapping type. Furthermore, in multi-cell multi-PDSCH / PUSCH scheduling, even if PDSCHs or PUSCHs of different cells have the same mapping type, different antenna port tables are applied depending on the scheduled cell. Therefore, in the following description, the problem of different antenna port tables depending on different mapping types will be described later, but this will be extended to the problem of different antenna port tables depending on different cells.

[0344] By configuring multiple PDSCH scheduling and multiple PUSCH scheduling, multiple scheduling information is configured in one Time Domain Resource Assignment (TDRA) row, and each of the multiple scheduling information has a Starting and Length Indication Value (SLIV) and a mapping type. Therefore, the terminal receives an indication of TDRA rows including scheduling information of different mapping types through one DCI.

[0345] Different DMRS configuration information is configured for different mapping types. When the DMRS configuration information is different, the antenna port table for indicating the DMRS port is different. The DCI format for scheduling the PDSCH or PUSCH includes an antenna port field for indicating one row of the antenna port table. However, as described above, the antenna port field of the DCI format is used to indicate one row of one antenna port table. However, when a TDRA row having multiple scheduling information of different mapping types is indicated to a terminal, the terminal needs to receive an indication of one row in each of the two antenna port tables. A method for this purpose will be described below.

[0346] The DMRS configuration constraints are introduced as follows.

[0347] In an embodiment of the present invention, the terminal expects that mapping type A and mapping type B use the same antenna port table. Here, in order to use the same antenna port table, the terminal is configured with the same DMRS type (dmrs-Type) and DMRS maximum length (maxLength) from a higher layer. The base station configures the terminal with the same DMRS type (dmrs-Type) and DMRS maximum length (maxLength).

[0348] When a TDRA table including TDRA rows with different mapping types is configured, the terminal expects mapping type A and mapping type B to use the same antenna port table. That is, when a TDRA table including TDRA rows with different mapping types is configured, the terminal expects the DMRS type (dmrs-Type) and DMRS maximum length (maxLength) of mapping type A and mapping type B to be the same.

[0349] When the base station configures a TDRA table including TDRA rows of different mapping types for a terminal, the base station must configure the terminal to use the same antenna port table for mapping type A and mapping type B. In other words, when the base station configures a TDRA table including TDRA rows of different mapping types for a terminal, the base station must configure the terminal to use the same DMRS type (dmrs-Type) and maximum DMRS length (maxLength) for mapping type A and mapping type B.

[0350] When a TDRA table that does not include TDRA rows of different mapping types is configured, the terminal expects that the antenna port tables of mapping type A and mapping type B are the same or different. That is, when a TDRA table that does not include TDRA rows of different mapping types is configured, the terminal expects that the DMRS type (dmrs-Type) and DMRS maximum length (maxLength) of mapping type A and mapping type B are the same or different. In other words, when a TDRA table that does not include TDRA rows of different mapping types is configured in the terminal, there is no setting constraint on the DMRS type (dmrs-Type) and DMRS maximum length (maxLength) of mapping type A and mapping type B.

[0351] When the base station configures a TDRA table that does not include TDRA rows of different mapping types for a terminal, the base station configures the terminal to use the same or different antenna port tables for mapping type A and mapping type B. That is, when the base station configures a TDRA table that does not include TDRA rows of different mapping types for a terminal, the base station configures the DMRS type (dmrs-Type) and DMRS maximum length (maxLength) of mapping type A and mapping type B for the terminal to be the same or different. In other words, when the base station configures a TDRA table that does not include TDRA rows of different mapping types for a terminal, the base station freely configures the DMRS type (dmrs-Type) and DMRS maximum length (maxLength) of mapping type A and mapping type B for the terminal without any configuration constraints.

[0352] In one embodiment, if at least one row in the TDRA table configured in the terminal is a TDRA of different mapping types, the DMRS type (dmrs-Type) and DMRS maximum length (maxLength) of mapping type A and mapping type B should be the same, which also affects other TDRA rows in the TDRA table.

[0353] For example, assume that the first TDRA row in the TDRA table includes scheduling information of mapping type A, and the second TDRA row includes scheduling information of mapping type B. In the existing operation (not performing the operation of the first embodiment), the base station sets different DMRS types (dmrs-Type) or DMRS maximum lengths (maxLength) for mapping type A and mapping type B in the terminal. Therefore, the PDSCH (or PUSCH) scheduled in the first TDRA row and the PDSCH (or PUSCH) scheduled in the second TDRA row have DMRS of different DMRS types (dmrs-Type) or DMRS maximum lengths (maxLength). However, in the operation of one embodiment, the PDSCH (or PUSCH) scheduled in the first TDRA row and the PDSCH (or PUSCH) scheduled in the second TDRA row must always have the same DMRS type (dmrs-Type) or DMRS maximum length (maxLength). This makes it difficult to set a DMRS suitable for the mapping type of the base station.

[0354] To solve this problem, the following embodiment is considered.

[0355] The UE additionally receives DMRS configurations for only TDRA rows of different mapping types from a higher layer signal (e.g., an RRC signal). The DMRS configuration includes at least a DMRS type (dmrs-Type) or a DMRS maximum length (maxLength). The UE receives three DMRS configurations as follows:

[0356] First DMRS configuration: DMRS configuration for a TDRA row that contains only scheduling information of Mapping type A

[0357] Second DMRS configuration: DMRS configuration for TDRA rows that contain only scheduling information of Mapping type B

[0358] Third DMRS configuration: DMRS configuration for a TDRA row including scheduling information of Mapping type A and scheduling information of Mapping type B

[0359] For reference, the first DMRS setting is the DMRS setting set to mapping type A ('dmrs-DownlinkForPDSCH-MappingTypeA' for PDSCH mapping type A, and 'dmrs-UplinkForPUSCH-MappingTypeA' for PUSCH mapping type A), the second DMRS setting is the DMRS setting set to mapping type B ('dmrs-DownlinkForPDSCH-MappingTypeB' for PDSCH mapping type B, and 'dmrs-UplinkForPUSCH-MappingTypeB' for PUSCH mapping type B), and the third DMRS setting is the newly configured DMRS setting.

[0360] When the terminal receives the DCI format, it performs the following operations:

[0361] The terminal obtains the index of the TDRA row from the TDRA field of the received DCI format, and obtains the scheduling information and the mapping type of the scheduling information contained in the TDRA row.

[0362] The UE assumes the first DMRS configuration if the TDRA row includes only scheduling information of mapping type A. Therefore, the UE determines the DMRS type (dmrs-Type) or the DMRS maximum length (maxLength) according to the first DMRS configuration, and uses an antenna port table according to the DMRS type (dmrs-Type) or the DMRS maximum length (maxLength).

[0363] If the TDRA row contains only scheduling information of mapping type B, the UE assumes the second DMRS configuration. Therefore, the UE determines the DMRS type (dmrs-Type) or the maximum DMRS length (maxLength) according to the second DMRS configuration, and uses the antenna port table according to the DMRS type (dmrs-Type) or the maximum DMRS length (maxLength).

[0364] If the TDRA row includes scheduling information of mapping type A and scheduling information of mapping type B, the terminal assumes a third DMRS configuration. Therefore, the DMRS type (dmrs-Type) or DMRS maximum length (maxLength) is determined by the third DMRS configuration, and the terminal uses an antenna port table according to the DMRS type (dmrs-Type) or DMRS maximum length (maxLength). Here, mapping type A and mapping type B scheduled in the TDRA row use the same antenna port table. Therefore, the DMRS configurations for mapping type A and mapping type B have the same DMRS port(s), the same number of DMRS symbols, and the same number of CDM groups without data. However, the position of the DMRS that is actually transmitted is determined differently depending on mapping type A and mapping type B.

[0365] The terminal interprets the antenna port field based on the antenna port table.

[0366] The interpretation of the antenna port field is as follows:

[0367] If the number of rows in the antenna port table corresponding to the first DMRS configuration is N1, the number of bits required is 'X1 (X1=ceil(log2(N1))).

[0368] If the number of rows in the antenna port table corresponding to the second DMRS configuration is N2, then the number of bits required is X2 (X2=ceil(log2(N2))).

[0369] If the number of rows in the antenna port table corresponding to the third DMRS configuration is N3, then the number of bits required is X3 (X3=ceil(log2(N3))).

[0370] The length of the antenna port field in the DCI format monitored by the terminal is determined as follows:

[0371] When only one of the three DMRS settings is configured in the terminal, the length of the antenna port field is one of X1 bits, X2 bits, or X3 bits according to the configured DMRS setting. That is, when only the first DMRS setting is configured in the terminal, the length of the antenna port field is X1 bit. When only the second DMRS setting is configured in the terminal, the length of the antenna port field is X2 bits. When only the second DMRS setting is configured in the terminal, the length of the antenna port field is X2 bits.

[0372] When only two of the three DMRS configurations are configured in the terminal, the length of the antenna port field is the maximum value of the number of bits required for the two configured DMRS configurations, i.e., max{Xn,Xm} bits. Here, n and m are determined by the configured DMRS configuration. That is, when the first DMRS configuration and the second DMRS configuration are configured in the terminal, the length of the antenna port field is max{X1,X2} bits. When the first DMRS configuration and the third DMRS configuration are configured in the terminal, the length of the antenna port field is max{X1,X3} bits. When the second DMRS configuration and the third DMRS configuration are configured in the terminal, the length of the antenna port field is max{X2,X3} bits.

[0373] When all three DMRS configurations are configured in the terminal, the length of the antenna port field is the maximum value of the number of bits required for the three configured DMRS configurations, i.e., max{X1, X2, X3} bits.

[0374] When the terminal interprets the antenna port field based on the antenna port table, not all bits of the antenna port field are necessary. For example, when all three DMRS settings are configured in the terminal, the DCI format monitored by the terminal includes an antenna port field of max{X1,X2,X3}bits. When the TDRA field of the DCI format includes only scheduling information in which the specified TDRA row is mapping type A, the least significant bit (LSB) X1bits of the max{{X1,X2,X3}bits antenna port field is necessary, but the most significant bit (MSB) max{X1,X2,X3}-X1bits is not necessary. Therefore, the terminal assumes that the MSB max{X1,X2,X3}X1bits of the antenna port field is padded with '0' and interprets the antenna port field based on this assumption.

[0375] When the TDRA row indicated by the TDRA field of the DCI format contains only scheduling information of mapping type B, the LSB X2bits of the max{X1,X2,X3}bits antenna port field is necessary, but the MSB max{X1,X2,X3}-X2bits is not. Therefore, the terminal assumes that the MSB max{X1,X2,X3}-X2bits of the antenna port field is padded with '0' (padding) and interprets the antenna port field based on this assumption.

[0376] When the TDRA row indicated by the TDRA field of the DCI format includes scheduling information of mapping type A and scheduling information of mapping type B, the LSB X3 bits of the max{X1,X2,X3}bit antenna port field is necessary, but the MSB max{X1,X2,X3}-X3 bits are not necessary. Therefore, the terminal assumes that the MSB max{X1,X2,X3}-X3 bits of the antenna port field are padded with '0' (padding) and interprets the antenna port field based on this assumption.

[0377] The third DMRS configuration is the same as either the first DMRS configuration or the second DMRS configuration. That is, when the terminal receives the third DMRS configuration, the terminal receives the same configuration as one of the first DMRS configuration or the second DMRS configuration, but does not receive a different configuration from the first DMRS configuration and the second DMRS configuration. Through this restriction, the terminal receives a maximum of two different DMRS configurations.

[0378] A new higher layer signal (eg, RRC signal) is required for the third DMRS configuration, which requires higher layer signal design and overhead. A method for improving this problem is described below.

[0379] The UE does not receive higher layer signal configuration for the third DMRS configuration. Instead, the third DMRS configuration is determined from the following information:

[0380] -First method: The terminal always assumes that the third DMRS configuration is the same as the first DMRS configuration. The terminal uses the DMRS configuration for the TDRA row including only scheduling information of mapping type A as the third DMRS configuration. In other words, the terminal determines the DMRS of mapping type B scheduled in the TDRA row of a different mapping type by using the DMRS configuration of mapping type A, i.e., the DMRS type (dmrs-Type) or the maximum DMRS length (maxLength). Therefore, the terminal uses the antenna port table of mapping type A for mapping type B scheduled in the TDRA row of a different mapping type. Here, the DMRS location of mapping type B follows the method of mapping type B as it is.

[0381] -Second method: The terminal always assumes that the third DMRS configuration is the same as the second DMRS configuration. That is, the terminal uses the DMRS configuration for the TDRA row including only scheduling information of mapping type B for the third DMRS configuration. In other words, the terminal determines the DMRS by using the DMRS configuration of mapping type B for mapping type A scheduled in the TDRA row of a different mapping type, i.e., the DMRS type (dmrs-Type) or the maximum DMRS length (maxLength). Thus, the terminal uses the antenna port table of mapping type B for mapping type A scheduled in the TDRA row of a different mapping type. Here, the DMRS location of mapping type A follows the method of mapping type A as it is.

[0382] -In the third method, the terminal assumes that the third DMRS configuration is the same as either the first DMRS configuration or the second DMRS configuration based on the mapping type of one of the scheduling information scheduled in the TDRA rows of different mapping types.

[0383] For example, the UE assumes that the third DMRS configuration is the same as either the first DMRS configuration or the second DMRS configuration based on the mapping type of the earliest scheduling information among the scheduling information scheduled in the TDRA rows of different mapping types. If the mapping type of the earliest scheduling information is mapping type A, the UE assumes that the DMRS configuration of mapping type A, i.e., the first DMRS configuration, is the same as the third DMRS configuration. If the mapping type of the earliest scheduling information is mapping type B, the UE assumes that the DMRS configuration of mapping type B, i.e., the second DMRS configuration, is the same as the third DMRS configuration.

[0384] Here, the earliest scheduling information is replaced with the latest scheduling information, where the earliest scheduling information is the scheduling information that is earliest in time.

[0385] According to one embodiment, multiple PDSCH / PUSCH scheduling introduces the same mapping type constraint.

[0386] When the antenna port table corresponding to mapping type A of the terminal is different from the antenna port table corresponding to mapping type B, the terminal expects the mapping type of the scheduling information included in the TDRA row to be the same. When the DMRS type (dmrs-Type) or the DMRS maximum length (maxLength) of mapping type A of the terminal is different from the DMRS type (dmrs-Type) or the DMRS maximum length (maxLength) of mapping type B of the terminal, the terminal expects the mapping type of the scheduling information included in the TDRA row to be the same.

[0387] In addition, when TDRA rows of different mapping types are set in the TDRA table, the terminal assumes that the antenna port table corresponding to mapping type A is the same as the antenna port table corresponding to mapping type B. When TDRA rows of different mapping types are set in the TDRA table, the terminal assumes that the DMRS type (dmrs-Type) or DMRS maximum length (maxLength) of mapping type A is the same as the DMRS type (dmrs-Type) or DMRS maximum length (maxLength) of mapping type B.

[0388] That is, the terminal does not expect that the DMRS type (dmrs-Type) or DMRS maximum length (maxLength) of mapping type A is different from the DMRS type (dmrs-Type) or DMRS maximum length (maxLength) of mapping type B, and that TDRA rows of different mapping types are configured in the TDRA table. The terminal does not expect that the antenna port table corresponding to mapping type A is different from the antenna port table corresponding to mapping type B, and that TDRA rows of different mapping types are configured in the TDRA table.

[0389] When the base station configures the DMRS type (dmrs-Type) or DMRS maximum length (maxLength) of mapping type A to be different from the DMRS type (dmrs-Type) or DMRS maximum length (maxLength) of mapping type B in the terminal, the base station always sets the mapping type of the scheduling information included in the TDRA row to be the same.

[0390] When a base station sets TDRA rows of different mapping types for a terminal in the TDRA table, the base station must set the DMRS type (dmrs-Type) or DMRS maximum length (maxLength) of mapping type A to be the same as the DMRS type (dmrs-Type) or DMRS maximum length (maxLength) of mapping type B.

[0391] In other words, the base station does not set the DMRS type (dmrs-Type) or DMRS maximum length (maxLength) of mapping type A to be different from the DMRS type (dmrs-Type) or DMRS maximum length (maxLength) of mapping type B, so that TDRA rows of different mapping types are not included in the TDRA table.

[0392] Since the PDSCH (or PUSCH) scheduled in the TDRA field of the received DCI format always has the same mapping type, the UE determines the position and length of the DMRS based on the DMRS setting of the mapping type. Also, the UE determines one antenna port table based on the DMRS setting of the mapping type. One row of one antenna port table is indicated by the antenna port field.

[0393] In one embodiment, the Antenna port field points to respective rows in two antenna port tables.

[0394] When TDRA rows of different mapping types are configured in the TDRA table, the terminal assumes respective antenna port fields for mapping type A and mapping type B in the DCI format to be monitored. Alternatively, the terminal assumes that the antenna port field in the DCI format to be monitored includes a bit for mapping type A and a bit for mapping type B.

[0395] The length of the Antenna port field is determined by X1+X2 bits.

[0396] The MSB X1bits of the antenna port field is used to indicate one row of the antenna port table according to the DMRS setting of mapping type A. The LSB X2bits of the antenna port field is used to indicate one row of the antenna port table according to the DMRS setting of mapping type B. Conversely, the MSB X1bits can be used for mapping type B and the LSB X2bits can be used for mapping type A.

[0397] For example, when TDRA rows of different mapping types are set in the TDRA table according to the third embodiment, the terminal acquires X1bits for indicating the antenna port table of mapping type A and X2bits for indicating the antenna port table of mapping type B in the DCI format to be monitored. The terminal receives an indication of one row in the antenna port table of mapping type A through X1bits and an indication of one row in the antenna port table of mapping type B through X2bits, and thus can freely indicate antenna ports.

[0398] In the third embodiment, X1+X2 bits are not always required in the DCI format monitored by the terminal. For example, if the TDRA row indicated by the TDRA field of the DCI format received by the terminal includes only one mapping type of scheduling information, X1+X2 bits are not required. For this reason, the antenna port field in the DCI format monitored by the terminal is determined as follows.

[0399] According to one method, if the TDRA table configured in the terminal contains at least one TDRA row containing a different mapping type, the DCI format monitored by the terminal contains X1+X2 bits. That is, even if the TDRA row indicated by the TDRA field of the DCI format contains only scheduling information of one mapping type, the terminal always receives an antenna port field of X1+X2 bits. In this case, the index value of the antenna port table row of one mapping type from the antenna port field obtained by the terminal can be obtained as follows:

[0400] The terminal assumes that X1+X2 bits is a binary number, converts it to a decimal number, and regards the value corresponding to the decimal number as an index of a row in the antenna port table. If the number of rows in the antenna port table is Ni and the number of bits required to indicate it is X=i(Xi=ceil(log2(Ni))), the terminal assumes that the MSB X1+X2-Xi=bits of the antenna port field are padded with '0'. Here, i=1 if one mapping type is mapping type A, and 2 if it is mapping type B.

[0401] If one mapping type is mapping type A, the index of the row in the antenna port table for mapping type A is obtained using the MSB X1bits of the antenna port field, and if one mapping type is mapping type B, the index of the row in the antenna port table for mapping type B is obtained using the LSB X2bits of the antenna port field. If one mapping type is mapping type A, the terminal assumes that the LSB X2bits of the antenna port field are filled with '0' (padding). If one mapping type is mapping type B, the terminal assumes that the MSB X1bit of the antenna port field is filled with '0' (padding).

[0402] According to another method, the length of the antenna port field changes according to the mapping type of the TDRA row indicated by the TDRA field of the DCI format received by the terminal. If the TDRA row indicated by the TDRA field of the DCI format received by the terminal includes only scheduling information of one mapping type, the terminal assumes that the received DCI format includes an antenna port field of max{X1,X2} bits. That is, if the TDRA row indicated by the TDRA field of the DCI format received by the terminal includes only scheduling information of one mapping type, the terminal assumes that the antenna port field includes the same number of bits as before.

[0403] When the TDRA row indicated by the TDRA field of the DCI format received by the terminal includes scheduling information of mapping type A and scheduling information of mapping type B, the terminal assumes that the received DCI format includes an antenna port field of X1+X2 bits. That is, when the TDRA row indicated by the TDRA field of the DCI format received by the terminal includes scheduling information of mapping type A and scheduling information of mapping type B, the terminal assumes that the antenna port field of X1+X2 bits according to the third embodiment of the present invention is included.

[0404] According to another method, the length of the antenna port field changes according to the number of scheduling information included in the TDRA row indicated by the TDRA field of the DCI format received by the terminal. If the TDRA row indicated by the TDRA field of the DCI format received by the terminal includes only one scheduling information, the terminal assumes that the received DCI format includes an antenna port field of max{X1,X2} bits. That is, if the TDRA row indicated by the TDRA field of the DCI format received by the terminal includes only one scheduling information, the terminal assumes that the antenna port field of the same bits as before is included.

[0405] When a TDRA row indicated by the TDRA field of the DCI format received by the terminal includes multiple pieces of scheduling information, the terminal assumes that the received DCI format includes an antenna port field of X1+X2 bits. That is, when a TDRA row indicated by the TDRA field of the DCI format received by the terminal includes multiple pieces of scheduling information, the terminal assumes that the antenna port field of X1+X2 bits according to the third embodiment of the present invention is included.

[0406] The terminal determines or assumes the length of the antenna port field according to the TDRA row indicated by the TDRA field of the received DCI format. When monitoring the DCI format, the terminal needs to know the length of the DCI format in advance. Therefore, if the length of the DCI format differs depending on the TDRA row indicated by the TDRA field, the terminal adjusts it to the length of the longest DCI format. That is, the terminal adds some bits to the shorter DCI format to adjust it to the length of the longest DCI format. The terminal adds some bits to the LSB of the shorter DCI format to adjust it to the length of the longest DCI format. Some bits are '0'.

[0407] In one embodiment, the Antenna port field points to one or more rows in an antenna port combination table.

[0408] The terminal receives a new antenna port combination table setting from the base station, and the antenna port field indicates one row of the antenna port combination table.

[0409] The new antenna port combination table is defined as follows:

[0410] Each row in the new antenna port combination table has a unique index.

[0411] A first index and a second index are set for each row of the new antenna port combination table. Here, the first index is the row index of one of the rows in the antenna port table of mapping type A. Here, the second index is the row index of one of the rows in the antenna port table of mapping type B.

[0412] When a new antenna port combination table is set, the terminal determines rows for the antenna port table as follows.

[0413] The terminal obtains the index of the row in the antenna port combination table from the antenna port field. The terminal acquires the first index and the second index set in the row of the antenna port combination table of the index. The terminal regards the first index as an index in the antenna port table of mapping type A, and regards the second index as an index in the antenna port table of mapping type B. Therefore, the terminal regards the row corresponding to the first index in the antenna port table of mapping type A as being specified by the row in the antenna port table of mapping type A, and regards the row corresponding to the second index in the antenna port table of mapping type B as being specified as the row in the antenna port table of mapping type B.

[0414] The antenna port combination table applies to all TDRA rows or to a specific TDRA row.

[0415] When an antenna port combination table is configured in a terminal, information on the DMRS and antenna port of the PDSCH (or PUSCH) of all TDRA rows is obtained from the antenna port combination table.

[0416] More specifically, if the TDRA row indicated by the TDRA field of the DCI format received by the terminal contains only scheduling information of mapping type A, the terminal determines the row of the antenna port combination table from the antenna port field, and determines the row of the antenna port table of mapping type A based on the first index of the antenna port combination table row. At this time, the second index corresponding to mapping type B that is not scheduled is ignored.

[0417] If the TDRA row indicated by the TDRA field of the DCI format received by the terminal contains only scheduling information of mapping type B, the terminal determines the antenna port combination table row from the antenna port field, and determines the antenna port table row of mapping type B based on the second index of the antenna port combination table row. At this time, the first index corresponding to mapping type A that is not scheduled is ignored.

[0418] If the TDRA row indicated by the TDRA field of the DCI format received by the terminal includes scheduling information of mapping type A and scheduling information of mapping type B, the terminal determines the row of the antenna port combination table from the antenna port field, and the terminal determines the antenna port table row of mapping type A based on the first index of the antenna port combination table row and the antenna port table row of mapping type B based on the second index.

[0419] Here, the antenna port table for mapping type A is an antenna port table based on the DMRS type (dmrs-Type) or DMRS maximum length (maxLength) set in mapping type A, and the antenna port table for mapping type B is an antenna port table based on the DMRS type (dmrs-Type) or DMRS maximum length (maxLength) set in mapping type B.

[0420] When using the first method, the length of the antenna port field is determined according to the number of rows set in the antenna port combination table. If the number of rows set in the antenna port combination table is Ncomb, the antenna port field is ceil(log2(Ncomb)) bits.

[0421] When an antenna port combination table is configured, the terminal uses the antenna port combination table when a TDRA row of a different mapping type is indicated, and uses the existing antenna port table (i.e., the antenna port table with DMRS setting set to mapping type A, the antenna port table with DMRS setting set to mapping type B) when a TDRA row having only scheduling information of one mapping type is indicated.

[0422] More specifically, if the TDRA row indicated by the TDRA field of the DCI format received by the UE includes only scheduling information of mapping type A, the UE obtains from the antenna port field the index of the row of the antenna port table determined by the DMRS type (dmrs-Type) or the DMRS maximum length (maxLength) of mapping type A. The UE obtains antenna port information from the row of the antenna port table of the index.

[0423] If the TDRA row indicated by the TDRA field of the DCI format received by the terminal contains only scheduling information of mapping type B, the terminal obtains from the antenna port field the index of the row of the antenna port table determined by the DMRS type (dmrs-Type) or DMRS maximum length (maxLength) of mapping type B. The terminal obtains antenna port information from the row of the antenna port table of the index.

[0424] When the TDRA row indicated by the TDRA field of the DCI format received by the terminal includes scheduling information of mapping type A and scheduling information of mapping type B, the terminal determines the row of the antenna port combination table from the antenna port field, and determines the antenna port table row of mapping type A based on the first index of the antenna port combination table row and the antenna port table row of mapping type B based on the second index.

[0425] The length of the antenna port field is determined according to the number of rows in the antenna port table of mapping type A, the number of rows in the antenna port table of mapping type B, and the number of rows set in the antenna port combination table. When the number of rows set in the antenna port combination table is Ncomb and the number of bits for indicating the rows in the antenna port combination table is Xcomb=ceil(log2(Ncomb)), for example, the length of the antenna port field is determined as follows. The length of the antenna port field in the DCI format is max{X1,X2,Xcomb}bits. Here, the length of the antenna port field is fixed regardless of the mapping type included in the TDRA row indicated by the TDRA field in the DCI format. Additionally or alternatively, the length of the antenna port field in the DCI format is max{X1,X2}bits or Xcomb bits. If the TDRA field of the DCI format received by the terminal contains only scheduling information of one mapping type in the TDRA row indicated by the TDRA field, the length of the Antenna port field is max{X1, X2} bits, and if the TDRA field of the DCI format received by the terminal contains only scheduling information of one mapping type in the TDRA row indicated by the TDRA field, the length of the Antenna port field is Xcomb bits.

[0426] When an antenna port combination table is configured, the terminal uses the antenna port combination table when a TDRA row including multiple scheduling information is indicated, and uses an existing antenna port table (i.e., the antenna port table based on the DMRS setting set to mapping type A, the antenna port table based on the DMRS setting set to mapping type B) when a TDRA row having only one scheduling information is indicated.

[0427] More specifically, if the TDRA row indicated by the TDRA field of the DCI format received by the terminal includes only scheduling information of mapping type A, the terminal obtains from the antenna port field the index of the row of the antenna port table determined by the DMRS type (dmrs-Type) or the DMRS maximum length (maxLength) of mapping type A. The terminal obtains antenna port information from the row of the antenna port table of the index.

[0428] If the TDRA row indicated by the TDRA field of the DCI format received by the terminal contains only scheduling information of mapping type B, the terminal obtains from the antenna port field the index of the row of the antenna port table determined by the DMRS type (dmrs-Type) or DMRS maximum length (maxLength) of mapping type B. The terminal obtains antenna port information from the row of the antenna port table of the index.

[0429] When the TDRA row indicated by the TDRA field of the DCI format received by the terminal contains multiple pieces of scheduling information, the terminal determines the row of the antenna port combination table from the antenna port field, and determines the antenna port table row of mapping type A based on the first index of the antenna port combination table row and the antenna port table row of mapping type B based on the second index.

[0430] The length of the antenna port field is determined according to the number of rows in the antenna port table of mapping type A, the number of rows in the antenna port table of mapping type B, and the number of rows set in the antenna port combination table. If the number of rows set in the antenna port combination table is Ncomb and the number of bits for indicating the rows of the antenna port combination table is Xcomb=ceil(log2(Ncomb)), the length of the antenna port field is determined as follows: The length of the antenna port field of the DCI format is max{X1,X2,Xcomb}bits. Here, the length of the antenna port field is fixed regardless of the number of scheduling information included in the TDRA row indicated by the TDRA field of the DCI format. Additionally or alternatively, the length of the antenna port field of the DCI format is max{X1,X2}bits or Xcomb bits. If the TDRA row indicated by the TDRA field in the DCI format received by the terminal contains only one scheduling information, the length of the Antenna port field is max{X1, X2} bits, and if the TDRA row indicated by the TDRA field in the DCI format received by the terminal contains only multiple scheduling information, the length of the Antenna port field is Xcomb bits.

[0431] According to an embodiment, the terminal is configured with an antenna port combination table for each rank to indicate an antenna port of a PUSCH from the base station. More specifically, the terminal is configured with an antenna port combination table for PUSCH of rank 1, an antenna port combination table for PUSCH of rank 2, an antenna port combination table for PUSCH of rank 3, and an antenna port combination table for PUSCH of rank 4. Here, a first index of the antenna port combination table for rank r (r=1,2,3,4) indicates a DMRS configuration of mapping type A and a row of the antenna port table corresponding to rank r (r=1,2,3,4), and a second index indicates a DMRS configuration of mapping type B and a row of the antenna port table corresponding to rank r (r=1,2,3,4).

[0432] The UE is configured with an antenna port combination table for indicating antenna ports of PDSCH from the base station according to the number of activated codewords. More specifically, the UE is configured with an antenna port combination table for PDSCH with one activated codeword (hereinafter, referred to as first table) and an antenna port combination table for PDSCH with two activated codewords (hereinafter, referred to as second table). The UE uses the first table when the PDSCH scheduled in the received DCI includes one activated codeword. That is, the first index of the first table indicates a row of the antenna port table corresponding to the DMRS setting of mapping type A, and obtains DMRS information (DMRS port(s), number of DMRS symbols, number of CDM groups without data) when the number of activated codewords in the row is one. The second index of the first table indicates a row of the antenna port table corresponding to the DMRS setting of mapping type B, and acquires DMRS information (DMRS port(s), number of DMRS symbols, number of DMRS CDM groups without data) when the number of activated codewords in the row is 1. Similarly, the terminal uses the second table when the PDSCH scheduled in the received DCI includes two activated codewords. That is, the first index of the second table indicates a row of the antenna port table corresponding to the DMRS setting of mapping type A, and acquires DMRS information (DMRS port(s), number of DMRS symbols, number of DMRS CDM groups without data) when the number of activated codewords in the row is 1. The second index of the second table indicates a row of the antenna port table corresponding to the DMRS setting of mapping type B, and acquires DMRS information (DMRS port(s), number of DMRS symbols, number of DMRS CDM groups without data) when the number of activated codewords in the row is 1.

[0433] In one embodiment, we expect antenna port field values ​​to indicate the same DMRS information.

[0434] When a TDRA row with a different mapping type is indicated by a received DCI format, the UE expects an antenna port field value indicating the same DMRS information even if a different antenna port table is used for each mapping type. Here, the same DMRS information is the same DMRS port(s), the same number of DMRS symbols (Number of front-load symbols), or the same number of DMRS CDM group(s) without data. When a base station indicates a TDRA row with a different mapping type for a transmitted DCI format and different antenna port tables are used for each mapping type, the base station does not indicate an antenna port field value indicating the same DMRS information.

[0435] The same DMRS information includes information that is the same in at least one of the following: DMRS port(s), number of DMRS symbols (Number of front-load symbols), or number of DMRS CDM group(s) without data (Number of DMRS CDM group(s) without data). For example, the same DMRS information is information that is the same in the DMRS port(s).

[0436] In other words, if the DCI format received by the terminal indicates a TDRA row with a different mapping type and a different antenna port table is used for each mapping type, the terminal does not expect an antenna port field value indicating other DMRS information. If the DCI format transmitted by the base station indicates a TDRA row with a different mapping type and a different antenna port table is used for each mapping type, the base station does not indicate an antenna port field value indicating other DMRS information.

[0437] Even if different antenna port tables are used for different mapping types, rows with the same index in the two antenna port tables have the same DMRS port. For example, when Table 41 (when dmrs-Type=1, maxLength=2) and Table 43 (when dmrs-Type=2, maxLength=1) are set for PDSCH mapping types A and B, it is confirmed that rows 0 to 10 of the two tables have the same DMRS port(s), the same number of DMRS symbols (Number of front-load symbols), and the same number of DMRS CDM group(s) without data when only one codeword is activated. Therefore, when any one of the rows is indicated, the DMRS and antenna port information of mapping type A and mapping type B is determined for the terminal.

[0438] According to one embodiment, it is expected that the value of the Antenna port field applies to the antenna port tables of the two mapping types, respectively.

[0439] When a TDRA row of a different mapping type is indicated, the terminal applies the value of the antenna port field to the antenna port tables of the two mapping types, respectively.

[0440] The terminal expects the value of the antenna port field to indicate a valid row (a row that is not reserved) in the antenna port tables of the two mapping types. In other words, if the value of the antenna port field is specified to an invalid value in one of the antenna port tables of the two mapping types, the terminal determines this to be an error case and ignores the DCI format including the antenna port field.

[0441] If the value of the antenna port field indicates a row that is not valid (a reserved row) in the antenna port table of the two mapping types, the terminal assumes that scheduling information of the mapping type that uses the antenna port table is not scheduled.

[0442] For example, when the TDRA row indicated by the TDRA field of the DCI format received by the terminal includes scheduling information of mapping type A and scheduling information of mapping type B, the terminal applies the value indicated by the antenna port field to each antenna port table to determine the row. That is, the terminal applies the value indicated by the antenna port field to the antenna port table of mapping type A to determine the DMRS information and antenna port information of mapping type A, and applies the value indicated by the antenna port field to the antenna port table of mapping type B to determine the DMRS information and antenna port information of mapping type B. If the row selected in the antenna port table of mapping type A is a valid row (a row that is not reserved) and the row selected in the antenna port table of mapping type B is a row that is not valid (a reserved row), the terminal receives (or transmits) a PDSCH (or PUSCH) corresponding to the scheduling information having mapping type A. However, the terminal does not receive (or transmit) a PDSCH (or PUSCH) corresponding to the scheduling information having mapping type B.

[0443] If a TDRA row of a different mapping type is indicated in the DCI format received by the terminal, the terminal shall interpret the value of the antenna port field as one of the valid rows of the antenna port table of the mapping type according to the defined rules.

[0444] Here, valid rows in the antenna port table are rows that are not reserved.

[0445] When Table 41 (when dmrs-Type=1, maxLength=2) and Table 43 (when dmrs-Type=2, maxLength=1) are set for PDSCH mapping types A and B, if the antenna port field indicates any one of rows 0 to 23 when only one codeword is activated, it is a valid value in the two antenna port tables. In other words, it is not a reserved row in the two antenna port tables. However, if the antenna port field indicates any one of rows 24 to 30, it is a valid value in one antenna port table (dmrs-Type=1, maxLength=2) but is an invalid value (reserved) in the other antenna port table (dmrs-Type=2, maxLength=1). Therefore, when a TDRA row of a different mapping type is indicated, the antenna port field does not indicate rows 24 to 30.

[0446] To solve this problem, the following method is applied.

[0447] The value specified in the antenna port field is reinterpreted based on the number of valid rows in the antenna port table to select a row in the antenna port table. For example, a row in the antenna port table is selected based on a value obtained by performing a modulo operation on the value specified in the antenna port field by the number of valid rows in the antenna port table.

[0448] For example, when Table 41 (when dmrs-Type=1, maxLength=2) and Table 43 (when dmrs-Type=2, maxLength=1) are set for PDSCH mapping types A and B, it is assumed that only one codeword is activated. Also, it is assumed that the value indicated in the Antenna port field is 25. As described above, row 25 is an invalid value (reserved) in the antenna port table (dmrs-Type=2, maxLength=1). To solve this, the terminal modulo-operates the value indicated in the antenna port field, 25, by 24, which is the number of valid rows in the antenna port table, to obtain 25 mod 24=1, and acquires DMRS information and antenna port information from row 1 of the antenna port table.

[0449] If the value indicated in the antenna port field indicates a valid value in one antenna port table but an invalid value (reserved) in another antenna port table, the terminal shall interpret that case as one of the valid values ​​as follows:

[0450] The terminal interprets the reserved value as a specific row having a valid value in the indicated antenna port table, where the specific row is row 0. As another example, the specific row is set by the base station in a higher layer.

[0451] The terminal interprets the valid value as being the specific row having a valid value in the antenna port table indicated, where the index of the specific row is the value indicated in the antenna port field. For example, row 25 is an invalid value (reserved) in the antenna port table (dmrs-Type=2, maxLength=1). In this case, row 25 of the antenna port table (dmrs-Type=1, maxLength=2) is used.

[0452] Although the first to sixth embodiments have been described separately for the sake of convenience, this is only for the sake of convenience, and each embodiment can be combined with each other to operate. Also, in various embodiments of the present invention, the operation of the terminal has been described for the sake of convenience, but the technical features of various embodiments of the present invention described in terms of the operation of the terminal are also applicable to the configuration and operation of the base station.

[0453] By the multiple PUSCH scheduling configuration, multiple scheduling information is configured in one TDRA (Time Domain Resource Assignment) row in the UE, and each of the multiple scheduling information has a SLIV (Starting and Length Indication Value) and a mapping type. Therefore, the UE is indicated, via one DCI, TDRA rows including scheduling information having different mapping types.

[0454] Different DMRS configuration information is configured for different mapping types. When the DMRS configuration information is different, the antenna port table for indicating the DMRS port is different. Therefore, in the terminal, a DMRS port(s) different from the PUSCH is configured for a different mapping type according to a different antenna port table.

[0455] For example, assume that the following is configured in the DMRS configuration for mapping type A.

[0456] DMRS type (dmrs-Type) = 1

[0457] DMRS maxLength=1

[0458] Furthermore, assume that the following is configured in the DMRS configuration for mapping type B.

[0459] DMRS type (dmrs-Type) = 1

[0460] DMRS max length (maxLength) = 2

[0461] Also, it is assumed that the rank is 2. For reference, the rank is information that the terminal can obtain through the DCI format. Therefore, the terminal uses one row (non-reserved row corresponding to index 0, 1, 2, 3) of Table 23 when determining a DMRS port for transmitting a PUSCH of mapping type A, and uses one row (non-reserved row corresponding to index 0, 1, ..., 9) of Table 27 when determining a DMRS port for transmitting a PUSCH of mapping type B. As an example, it is assumed that the base station indicates DMRS port {0, 1} for transmitting a PUSCH of mapping type A and indicates DMRS port {0, 2} for transmitting a PUSCH of mapping type B. In this case, it is confirmed that different DMRS ports are mapped to different mapping types for PUSCH transmission in the terminal. Therefore, the DMRS port for transmitting a PUSCH of mapping type A in the terminal is different from the DMRS port for transmitting a PUSCH of mapping type B.

[0462] The UE must be indicated the index of the DMRS port for PTRS transmission. The DCI format for scheduling the PUSCH includes a PTRS-DMRS association field for indicating the DMRS port for PTRS transmission. As described above, the PTRS-DMRS association field indicates one antenna port among the DMRS ports of the scheduled PUSCH, and when transmitting the PUSCH, the PTRS is transmitted on the indicated antenna port.

[0463] As described above, the PTRS-DMRS association field is indicated as one of the following according to Table 49-1: {1st scheduled DMRS port, 2nd scheduled DMRS port, 3rd scheduled DMRS port, 4th scheduled DMRS port}Assume that the current PTRS-DMRS association field indicates the 2nd scheduled DMRS port. In this case, as per the previous example, in the case of mapping type A, the PTRS antenna port is DMRS port 1 because PUSCH is transmitted on DMRS port {0,1}, and in the case of mapping type B, the PTRS antenna port is DMRS port 2 because PUSCH is transmitted on DMRS port {0,2}. Therefore, in the case of different mapping types, different DMRS ports are used for PTRS transmission.

[0464] In order to obtain the highest performance, the base station must select the DMRS port with the highest received signal power among the DMRS ports at the PTRS antenna port. This is the reason why the base station indicates one DMRS port in the PTRS-DMRS association field in the DCI format. However, in the case of different mapping types, the DMRS port differs depending on the mapping type, so the base station does not indicate to the terminal the DMRS port with the highest received signal power simultaneously for two different mapping types. For example, in the above example, the terminal transmits the PTRS on DMRS port 1 by the PUSCH with mapping type A, and transmits the PTRS on DMRS port 2 by the PUSCH with mapping type B. In this case, assuming that the power of the received signal for each DMRS port is DMRS port 1>DMRS port 0>DMRS port 2, the base station must instruct the terminal to transmit the PTRS on DMRS port 1 of the PUSCH with mapping type A, and transmit the PTRS on DMRS port 0 by the PUSCH with mapping type B. However, the DCI format does not support such an indication. Hereinafter, the present invention will disclose a method for determining a PTRS antenna port for different mapping types.

[0465] The introduction of the same DMRS port(s) constraint and the same DMRS port(s) indication constraint will now be described.

[0466] The terminal expects that mapping type A and mapping type B use the same antenna port table. Here, in order to use the same antenna port table, the terminal is configured with the same DMRS type (dmrs-Type) and DMRS maximum length (maxLength) from a higher layer. The base station configures the terminal with the same DMRS type (dmrs-Type) and DMRS maximum length (maxLength). In addition, the terminal expects that the same DMRS port(s) is instructed for mapping type A and mapping type B.

[0467] When a TDRA table including TDRA rows of different mapping types is configured, the UE expects mapping type A and mapping type B to use the same antenna port table. That is, when a TDRA table including TDRA rows of different mapping types is configured, the UE expects the DMRS type (dmrs-Type) and DMRS maximum length (maxLength) of mapping type A and mapping type B to be the same. The UE expects the DMRS port(s) of PUSCH, which is a mapping type indicated in the DCI format for scheduling the received PUSCH, to always be the same as the PUSCH DMRS port(s) of mapping type B.

[0468] When the base station configures a TDRA table including TDRA rows of different mapping types for a terminal, the base station must configure the terminal to use the same antenna port table for mapping type A and mapping type B. That is, when the base station configures a TDRA table including TDRA rows of different mapping types for a terminal, the base station must configure the terminal to use the same DMRS type (dmrs-Type) and DMRS maximum length (maxLength) for mapping type A and mapping type B.

[0469] When a TDRA table that does not include TDRA rows of different mapping types is configured in a terminal, the antenna port tables of mapping type A and mapping type B are the same or different. That is, when a TDRA table that does not include TDRA rows of different mapping types is configured in a terminal, the DMRS type (dmrs-Type) and DMRS maximum length (maxLength) of mapping type A and mapping type B are the same or different. In other words, when a TDRA table that does not include TDRA rows of different mapping types is configured in a terminal, there are no setting constraints on the DMRS type (dmrs-Type) and DMRS maximum length (maxLength) of mapping type A and mapping type B.

[0470] When the base station configures a TDRA table that does not include TDRA rows of different mapping types for a terminal, the base station configures the terminal to use the same or different antenna port tables for mapping type A and mapping type B. That is, when the base station configures a TDRA table that does not include TDRA rows of different mapping types for a terminal, the base station configures the DMRS type (dmrs-Type) and DMRS maximum length (maxLength) of mapping type A and mapping type B for the terminal to be the same or different. In other words, when the base station configures a TDRA table that does not include TDRA rows of different mapping types for a terminal, the base station freely configures the DMRS type (dmrs-Type) and DMRS maximum length (maxLength) of mapping type A and mapping type B for the terminal without any configuration constraints.

[0471] If at least one row in the TDRA table configured in the terminal is a TDRA row with a different mapping type, the DMRS type (dmrs-Type) and the DMRS maximum length (maxLength) of mapping type A and mapping type B must be the same. This also affects other TDRA rows in the TDRA table.

[0472] For example, assume that the first TDRA row in the TDRA table includes scheduling information of mapping type A, and the second TDRA row includes scheduling information of mapping type B. In the existing operation (not performing the operation of the first embodiment), the base station sets different DMRS types (dmrs-Type) or DMRS maximum lengths (maxLength) for mapping type A and mapping type B in the terminal. Therefore, the PUSCH scheduled in the first TDRA row and the PUSCH scheduled in the second TDRA row can have DMRS of different DMRS types (dmrs-Type) or DMRS maximum lengths (maxLength). However, in the operation of the first embodiment, the PUSCH scheduled in the first TDRA row and the PUSCH scheduled in the second TDRA row must always have the same DMRS type (dmrs-Type) or DMRS maximum length (maxLength). This makes it difficult to configure a DMRS suitable for the mapping type of the base station.

[0473] To solve this problem, the following embodiment is considered.

[0474] The UE additionally receives DMRS configurations for only TDRA rows of different mapping types from a higher layer signal (e.g., an RRC signal). The DMRS configuration includes at least a DMRS type (dmrs-Type) or a DMRS maximum length (maxLength). The UE receives three DMRS configurations as follows:

[0475] First DMRS configuration: DMRS configuration for a TDRA row that contains only scheduling information of Mapping type A

[0476] Second DMRS configuration: DMRS configuration for TDRA rows that contain only scheduling information of Mapping type B

[0477] Third DMRS configuration: DMRS configuration for a TDRA row including scheduling information of Mapping type A and scheduling information of Mapping type B

[0478] For reference, the first DMRS setting is a DMRS setting set to Mapping type A (dmrs-UplinkForPUSCH-MappingTypeA), the second DMRS setting is a DMRS setting set to Mapping type B (dmrs-UplinkForPUSCH-MappingTypeB), and the third DMRS setting is a newly configured DMRS setting.

[0479] When the terminal receives the DCI format, it performs the following operations:

[0480] The terminal obtains the index of the TDRA row from the TDRA field of the received DCI format. The terminal obtains the scheduling information and the mapping type of the scheduling information contained in the TDRA row.

[0481] The UE assumes the first DMRS configuration if the TDRA row includes only scheduling information with mapping type A. Therefore, the UE determines the DMRS type (dmrs-Type) or the DMRS maximum length (maxLength) according to the first DMRS configuration, and uses an antenna port table according to the DMRS type (dmrs-Type) or the DMRS maximum length (maxLength).

[0482] If the TDRA row includes only scheduling information of mapping type B, the UE assumes the second DMRS configuration. Therefore, the UE determines the DMRS type (dmrs-Type) or the DMRS maximum length (maxLength) according to the second DMRS configuration, and uses the antenna port table according to the DMRS type (dmrs-Type) or the DMRS maximum length (maxLength).

[0483] If the TDRA row includes scheduling information of mapping type A and scheduling information of mapping type B, the UE assumes a third DMRS configuration. Thus, the UE determines the DMRS type (dmrs-Type) or the DMRS maximum length (maxLength) according to the third DMRS configuration, and uses an antenna port table according to the DMRS type (dmrs-Type) or the DMRS maximum length (maxLength). Here, mapping type A and mapping type B scheduled in the TDRA row use the same antenna port table. Thus, the DMRS configurations for mapping type A and mapping type B have the same DMRS port(s), the same number of DMRS symbols, and the same number of CDM groups without data. However, the position of the DMRS that is actually transmitted is determined differently depending on mapping type A and mapping type B.

[0484] The terminal interprets the antenna port field based on the antenna port table.

[0485] The terminal obtains the DMRS port(s) in the antenna port table according to the value of the antenna port field. The DMRS port(s) is the same as the PUSCH with mapping type A and the PUSCH with mapping type B.

[0486] The terminal is instructed to use one of the DMRS ports of the DMRS port(s) as the PTRS antenna port from the PTRS-DMRS association field of the received DCI format. Since the DMRS port of the PUSCH with mapping type A and the DMRS port of the PUSCH with mapping type B are the same, the PTRS antenna port is also the same.

[0487] The third DMRS configuration is the same as either the first DMRS configuration or the second DMRS configuration. That is, when the third DMRS configuration is configured, the terminal is configured with the same configuration as one of the first DMRS configuration or the second DMRS configuration, but is not configured with a different configuration from the first DMRS configuration and the second DMRS configuration. Through this restriction, the terminal is configured with a maximum of two different DMRSs.

[0488] A new higher layer signal (eg, RRC signal) is required for the third DMRS configuration, which causes higher layer signal design and overhead. A method for improving this problem will be described below.

[0489] The UE is not configured with a higher layer signal for the third DMRS configuration. Instead, the third DMRS configuration is determined from the following information:

[0490] The UE always assumes that the third DMRS configuration is the same as the first DMRS configuration. That is, the UE uses the DMRS configuration for the TDRA row including only the scheduling information of mapping type A as the third DMRS configuration. In other words, the UE determines the DMRS by using the DMRS configuration of mapping type A, i.e., the DMRS type (dmrs-Type) or the maximum DMRS length (maxLength) for the PUSCH of mapping type B scheduled in the TDRA row of a different mapping type. Therefore, the UE uses the antenna port table of mapping type A for the PUSCH of mapping type B scheduled in the TDRA row of a different mapping type. Here, the DMRS location of the PUSCH of mapping type B follows the scheme of mapping type B as it is.

[0491] The UE always assumes that the third DMRS configuration is the same as the second DMRS configuration. That is, the UE uses the DMRS configuration for the TDRA row including only the scheduling information of mapping type B as the third DMRS configuration. In other words, the UE determines the DMRS by using the DMRS configuration of mapping type B, i.e., the DMRS type (dmrs-Type) or the maximum DMRS length (maxLength) for the PUSCH of mapping type A scheduled in the TDRA row of a different mapping type. Therefore, the UE uses the antenna port table of mapping type B for the PUSCH of mapping type A scheduled in the TDRA row of a different mapping type. Here, the DMRS location of the PUSCH of mapping type A follows the scheme of mapping type A as it is.

[0492] The terminal assumes that the third DMRS configuration is the same as either the first DMRS configuration or the second DMRS configuration based on the mapping type of one of the scheduling information scheduled in the TDRA rows of different mapping types.

[0493] For example, the UE assumes that the third DMRS configuration is the same as either the first DMRS configuration or the second DMRS configuration based on the mapping type of the earliest scheduling information among the scheduling information scheduled in the TDRA rows of different mapping types. If the mapping type of the earliest scheduling information is mapping type A, the UE assumes that the DMRS configuration of mapping type A, i.e., the first DMRS configuration, is the same as the third DMRS configuration. If the mapping type of the earliest scheduling information is mapping type B, the UE assumes that the DMRS configuration of mapping type B, i.e., the second DMRS configuration, is the same as the third DMRS configuration.

[0494] Here, the earliest scheduling information is replaced with the latest scheduling information, where the earliest scheduling information is the earliest scheduling information in time.

[0495] In this embodiment, it is assumed that the UEs are configured with the same DMRS type (dmrs-Type) or the same DMRS maximum length (maxLength). However, the above conditions are modified and applied as follows.

[0496] The terminal expects the same DMRS type (dmrs-Type) to be configured for different mapping types. Here, different DMRS maximum lengths (maxLength) are configured for different mapping types. Due to this condition change, the terminal uses different DMRS maximum lengths for different mapping types. Therefore, the base station instructs the terminal to use a DMRS length that is suitable for the mapping type. However, in this embodiment, the terminal expects to be instructed on the same DMRS port(s) for mapping type A and mapping type B.

[0497] The terminal expects the same DMRS maximum length (maxLength) to be set for different mapping types. Here, different DMRS types (dmrs-Type) are set for different mapping types. Due to this condition change, the terminal uses different DMRS types (dmrs-Type) for different mapping types. Therefore, the base station sets a DMRS type that matches the mapping type to the terminal. However, the terminal expects to be instructed to use the same DMRS port(s) for mapping type A and mapping type B.

[0498] The conditions for the DMRS type (dmrs-Type) or DMRS maximum length (maxLength) of the terminal have been described, but the following conditions are added.

[0499] The terminal expects the setting of additional DMRSs (dmrs-AdditionalPosition) other than the same first DMRS (first DMRS or front-loaded DMRS) for different mapping types.

[0500] There are restrictions on the DMRS configuration of mapping type A and mapping type B. For example, the same DMRS type (dmrs-Type) or the same maximum DMRS length (maxLength) must be set for mapping type A and mapping type B. However, without the above restrictions, the terminal expects to always be instructed to the same DMRS port(s).

[0501] The terminal expects that the same DMRS port(s) is indicated for mapping type A and mapping type B. Here, the antenna port table for PUSCH with mapping type A may be the same as or different from the antenna port table for PUSCH with mapping type B. That is, the DMRS type (dmrs-Type) and the DMRS maximum length (maxLength) that the base station configures for the terminal may be the same as or different from each other. Therefore, the antenna port table corresponding to mapping type A may be the same as or different from the antenna port table corresponding to mapping type B. However, when TDRA rows of different mapping types are indicated in the received DCI format, the terminal expects that the DMRS port(s) of mapping type A and the DMRS port(s) of mapping type B determined by the antenna port field of the DCI format are always the same as each other.

[0502] The base station can freely configure DMRS settings for mapping type A and mapping type B to the terminal. The DMRS settings include the DMRS type (dmrs-Type) and the maximum DMRS length (maxLength). Here, freely configuring means that the DMRS settings for mapping type A are independent of the DMRS settings for mapping type B. When the base station instructs the terminal to have TDRA rows of different mapping types in the DCI format, the base station must instruct the terminal to use the antenna port field value so that the DMRS port(s) of mapping type A and the DMRS port(s) of mapping type B indicated in the antenna port field of the DCI format are the same.

[0503] Multiple PUSCH scheduling introduces the same mapping type constraint

[0504] When the antenna port table corresponding to mapping type A of the terminal is different from the antenna port table corresponding to mapping type B, the terminal expects the mapping type of the scheduling information included in the TDRA row to be the same. When the DMRS type (dmrs-Type) or the DMRS maximum length (maxLength) of mapping type A of the terminal is different from the DMRS type (dmrs-Type) or the DMRS maximum length (maxLength) of mapping type B of the terminal, the terminal expects the mapping type of the scheduling information included in the TDRA row to be the same.

[0505] In addition, when TDRA rows of different mapping types are set in the TDRA table, the terminal assumes that the antenna port table corresponding to mapping type A is the same as the antenna port table corresponding to mapping type B. When TDRA rows of different mapping types are set in the TDRA table, the terminal assumes that the DMRS type (dmrs-Type) or DMRS maximum length (maxLength) of mapping type A is the same as the DMRS type (dmrs-Type) or DMRS maximum length (maxLength) of mapping type B.

[0506] That is, the terminal does not expect that the DMRS type (dmrs-Type) or DMRS maximum length (maxLength) of mapping type A is different from the DMRS type (dmrs-Type) or DMRS maximum length (maxLength) of mapping type B, and that TDRA rows of different mapping types are configured in the TDRA table. The terminal does not expect that the antenna port table corresponding to mapping type A is different from the antenna port table corresponding to mapping type B, and that TDRA rows of different mapping types are configured in the TDRA table.

[0507] When the base station configures the DMRS type (dmrs-Type) or DMRS maximum length (maxLength) of mapping type A to be different from the DMRS type (dmrs-Type) or DMRS maximum length (maxLength) of mapping type B in the terminal, the base station configures the mapping type of the scheduling information included in the TDRA row to always be the same.

[0508] When a base station sets TDRA rows of different mapping types for a terminal in the TDRA table, the base station must set the DMRS type (dmrs-Type) or DMRS maximum length (maxLength) of mapping type A to be the same as the DMRS type (dmrs-Type) or DMRS maximum length (maxLength) of mapping type B.

[0509] That is, the base station sets the DMRS type (dmrs-Type) or DMRS maximum length (maxLength) of mapping type A to be different from the DMRS type (dmrs-Type) or DMRS maximum length (maxLength) of mapping type B, and does not set the TDRA table to include TDRA rows of different mapping types.

[0510] Since the PUSCH scheduled in the TDRA field of the received DCI format always has the same mapping type, the UE determines the position and length of the DMRS based on the DMRS setting of the mapping type. Also, the UE determines one antenna port table based on the DMRS setting of the mapping type. One row of one antenna port table is indicated by the antenna port field.

[0511] The PTRS-DMRS association field indicates the PTRS antenna port for each of the two mapping types.

[0512] The DCI format for scheduling the PUSCH received by the terminal includes a DCI field for indicating the PTRS antenna port of each mapping type.

[0513] More specifically, some bits of the PTRS-DMRS association field indicate one of the DMRS port(s) of mapping type A as the PTRS antenna port, and the remaining bits of the PTRS-DMRS association field indicate one of the DMRS port(s) of mapping type B as the PTRS antenna port.

[0514] When TDRA rows of different mapping types are specified to the terminal, the PTRS-DMRS association field of the DCI format is composed of 4 bits, where the 2 most significant bits (MSBs) indicate one of the DMRS port(s) of mapping type A as the PTRS antenna port, and the 2 least significant bits (LSBs) indicate one of the DMRS port(s) of mapping type B as the PTRS antenna port.

[0515] When a TDRA row of one mapping type is specified to the terminal, the PTRS-DMRS association field of the DCI format is configured with 2 bits. The 2 bits indicate one of the DMRS port(s) of the mapping type included in the TDRA row as the PTRS antenna port.

[0516] For reference, in the above example, when the terminal schedules a PUSCH of a mapping type in a TDRA row in the DCI format, the number of bits of the PTRS-DMRS association field required by the terminal in the DCI format is different from that when the terminal schedules a PUSCH of one mapping type. Therefore, in order to match the bits, the following operation is performed.

[0517] If at least one TDRA row in the TDRA table configured in the terminal contains a different mapping type, the terminal always expects 4 bits in the PTRS-DMRS association in the DCI format. If a TDRA row of one mapping type is specified in the terminal, 2 bits out of the 4 bits in the PTRS-DMRS association field in the DCI format indicate one of the DMRS port(s) of the mapping type included in the TDRA row as the PTRS antenna port. The 2 bits out of the 4 bits are selected as follows:

[0518] The 2 MSB bits are used to select one of the DMRS port(s) of one mapping type included in the TDRA row as the PTRS antenna port, and the 2 LSB bits are unused.

[0519] The 2 LSB bits are used to select one of the DMRS port(s) of one mapping type included in the TDRA row as the PTRS antenna port, and the 2 MSB bits are unused.

[0520] Either the 2 MSB bits or the 2 LSB bits are used according to one mapping type included in the TDRA row. If one mapping type included in the TDRA row is mapping type A, the 2 MSB bits are used and one of the DMRS port(s) of that mapping type is used as the PTRS antenna port. If one mapping type included in the TDRA row is mapping type B, the 2 LSB bits are used and one of the DMRS port(s) of that mapping type is used as the PTRS antenna port.

[0521] When TDRA rows of different mapping types are specified to the terminal and the DMRS port(s) of the different mapping types are different, the PTRS-DMRS association field of the DCI format is composed of 4 bits, where the 2 most significant bits (MSBs) indicate one of the DMRS port(s) of mapping type A as the PTRS antenna port, and the 2 least significant bits (LSBs) indicate one of the DMRS port(s) of mapping type B as the PTRS antenna port.

[0522] When a TDRA row of one mapping type is specified to the terminal, or when TDRA rows of different mapping types are specified but the DMRS port(s) of the different mapping types are the same, the PTRS-DMRS association field of the DCI format is configured with 2 bits. The 2 bits indicate one of the DMRS port(s) of the mapping type included in the TDRA row as the PTRS antenna port.

[0523] For reference, in the above example, when the terminal schedules a PUSCH with a different mapping type in the DCI format and a PUSCH with the same mapping type in the DCI format, the number of bits of the PTRS-DMRS association field required by the terminal is different. Therefore, in order to match the bits, the following operation is performed.

[0524] If at least one TDRA row in the TDRA table configured in the terminal includes different mapping types and the DMRS port(s) of the different mapping types are specified to be different, the terminal always expects 4 bits in the PTRS-DMRS association in the DCI format. If a TDRA row of one mapping type is specified to the terminal or a TDRA row of different mapping types is specified but the DMRS port(s) of the different mapping types are the same, 2 bits out of the 4 bits in the PTRS-DMRS association field in the DCI format indicates one of the DMRS port(s) of the mapping type included in the TDRA row as the PTRS antenna port. The 2 bits out of the 4 bits are selected using the above three methods.

[0525] In other words, the conditions for the existence of the 4 bits PTRS-DMRS association field in the DCI format are as follows.

[0526] Condition 1) At least one row in the TDRA table contains a different mapping type, or

[0527] Condition 2) At least one row in the TDRA table includes a different mapping type, and different DMRS port(s) are indicated for the different mapping types.

[0528] For reference, if the terminal expects that the same DMRS port(s) will always be indicated, a 4-bit PTRS-DMRS association field will be present in the DCI format when condition 1 is used, but a 2-bit PTRS-DMRS association field will be present in the DCI format when condition 2 is used.

[0529] Although different bits are included in one PTRS-DMRS association field to indicate PTRS antenna ports of different mapping types, a new DCI field is defined. That is, in the above embodiment, the 4-bit PTRS-DMRS association field is represented by a 2-bit first PTRS-DMRS association field and a 2-bit second PTRS-DMRS association field. Preferably, the 2-bit first PTRS-DMRS association field is the MSB 2 bits of the above-mentioned 4-bit PTRS-DMRS association field, and the 2-bit second PTRS-DMRS association field is the LSB 2 bits of the above-mentioned 4-bit PTRS-DMRS association field.

[0530] The PTRS-DMRS association field indicates one of the DMRS ports commonly scheduled for the two mapping types.

[0531] The terminal receives an indication of one of the commonly selected DMRS port(s) among the DMRS port(s) of different mapping types in the PTRS-DMRS association field, where the PTRS-DMRS association field is 2 bits.

[0532] It is assumed that the terminal receives {3,4,5} as the DMRS port(s) of mapping type A and {2,3,5} as the DMRS port(s) of mapping type B. Here, mapping type A is the case where the DMRS type (dmrs-Type) is 2, the maximum DMRS length (maxLength) is 2, the rank is 3, and the row corresponding to value2 is indicated in the Antenna port table. Mapping type B is the case where the DMRS type (dmrs-Type) is 1, the maximum DMRS length (maxLength) is 2, the rank is 3, and the row corresponding to value2 is indicated in the Antenna port table.

[0533] The terminal generates a commonly scheduled DMRS port(s) by collecting the DMRS port(s) that are included in common among the DMRS port(s) of mapping type A and the DMRS port(s) of mapping type B. That is, the terminal generates the DMRS port(s) {3,5}, which is the DMRS port(s) that are included in common among the DMRS port(s) {3,4,5} of mapping type A and the DMRS port(s) {2,3,5} of mapping type B, as the commonly scheduled DMRS port(s).

[0534] The terminal receives an indication of one of the commonly scheduled DMRS port(s) in the PTRS-DMRS association field and uses the DMRS port for PTRS transmission. The PTRS-DMRS association field indicates one of the values ​​of '1st commonly scheduled DMRS port', '2nd commonly scheduled DMRS port', '3rd commonly scheduled DMRS port', and '4th commonly scheduled DMRS port', in ascending order. For example, if the commonly scheduled DMRS port(s) is {3,5} and the PTRS-DMRS association field indicates '1st commonly scheduled DMRS port', the terminal uses DMRS port(s) 3 as the antenna port for PTRS transmission. If the PTRS-DMRS association field indicates '2nd commonly scheduled DMRS port', the terminal uses DMRS port(s) 5 as the antenna port for PTRS transmission.

[0535] It is assumed that at least the DMRS port having the highest received signal power is included in both of the two different mapping types. That is, it is not a proper operation for the base station to schedule the DMRS port having the highest received power for scheduling the PUSCH of mapping type A and the PUSCH of mapping type B to the terminal, but not to schedule it to a different mapping type than the one to which it is scheduled. Therefore, at least one of the DMRS port(s) commonly scheduled to two different mapping types has the highest received signal power, and at least one of them is used as an antenna port for PTRS transmission.

[0536] However, the above assumption is not always valid. Therefore, the DMRS port with the highest received power belongs to only one mapping type. Therefore, the embodiment is as follows.

[0537] The PTRS-DMRS association field indicates one of the two mapping types among all DMRS ports scheduled.

[0538] The UE receives an indication of one or more DMRS port(s) obtained by collecting all the DMRS port(s) of different mapping types from the PTRS-DMRS association field, where the PTRS-DMRS association field is greater than 2 bits, where the PTRS-DMRS association field is 3 bits.

[0539] For example, assume that the terminal receives {3,4,5} as the DMRS port(s) of mapping type A and {2,3,6} as the DMRS port(s) of mapping type B. Here, mapping type A is the case where the DMRS type (dmrs-Type) is 2, the maximum DMRS length (maxLength) is 2, the rank is 3, and the row corresponding to value2 is specified in the Antenna port table. Mapping type B is the case where the DMRS type (dmrs-Type) is 1, the maximum DMRS length (maxLength) is 2, the rank is 3, and the row corresponding to value2 is specified in the Antenna port table.

[0540] The UE generates all of scheduled DMRS port(s) from the DMRS port(s) by collecting both the DMRS port(s) of mapping type A and the DMRS port(s) of mapping type B. That is, by collecting both the DMRS port(s) {3,4,5} of mapping type A and the DMRS port(s) {2,3,6} of mapping type B, the UE generates the entire DMRS port(s) {3,4,5,6} as all of scheduled DMRS port(s).

[0541] The terminal receives an indication of one DMRS port among all of scheduled DMRS port(s) in the PTRS-DMRS association field and uses the DMRS port for PTRS transmission. The PTRS-DMRS association field indicates one of the values ​​'1st all of scheduled DMRS port', '2nd all of scheduled DMRS port', '3rd all of scheduled DMRS port', '4th all of scheduled DMRS port', '5th all of scheduled DMRS port', '6th all of scheduled DMRS port', '7th all of scheduled DMRS port', and '8th all of scheduled DMRS port', in ascending order. For example, if all of scheduled DMRS port(s) is {3,4,5,6} and the PTRS-DMRS association field indicates '1st all of scheduled DMRS port', the terminal uses DMRS port(s) 3 as the antenna port for PTRS transmission. If the PTRS-DMRS association field indicates '2nd all of scheduled DMRS port', the terminal uses DMRS port(s) 4 as the antenna port for PTRS transmission. If the PTRS-DMRS association field indicates '3rd all of scheduled DMRS port', the terminal uses DMRS port(s) 5 as the antenna port for PTRS transmission. If the PTRS-DMRS association field indicates '4th all of scheduled DMRS port', the terminal uses DMRS port(s) 6 as the antenna port for PTRS transmission.

[0542] The PTRS-DMRS association field directly indicates the index of the DMRS antenna port.

[0543] The terminal receives an indication of one of the DMRS port(s) scheduled for different mapping types from the PTRS-DMRS association field, and uses one DMRS port for PTRS transmission based on the indication. In one embodiment, the terminal receives an indication of one of the possible DMRS port(s) regardless of scheduling. That is, the PTRS-DMRS association field indicates the index of one of the possible DMRS ports.

[0544] Here, the DMRS ports that can be specified are all DMRS ports that can be used according to the DMRS type (dmrs-Type). For example, when 1 is set as the DMRS type (dmrs-type), the available DMRS ports are 0 to 7. When 2 is set as the DMRS type (dmrs-type), the available DMRS ports are 0 to 11. When 1 and 2 are simultaneously set as the DMRS types (dmrs-type) for different mapping types, the available DMRS ports are 0 to 11. The PTRS-DMRS association field indicates the index of one of the available DMRS ports.

[0545] Here, the instructable DMRS ports are all DMRS ports that can be used according to the DMRS type (dmrs-Type) and maximum DMRS length (maxLength). When 1 is set as the DMRS type (dmrs-type) and the maximum DMRS length is 1, the available DMRS ports are 0 to 3. When 1 is set as the DMRS type (dmrs-type) and the maximum DMRS length is 2, the available DMRS ports are 0 to 7. When 2 is set as the DMRS type (dmrs-type) and the maximum DMRS length is 1, the available DMRS ports are 0 to 5. When 2 is set as the DMRS type (dmrs-type) and the maximum DMRS length is 2, the available DMRS ports are 0 to 11. When the DMRS type (dmrs-type) or maximum DMRS length is set to different mapping types, the maximum DMRS port for each setting is the available DMRS port.

[0546] Here, the DMRS ports that can be specified are a part of the DMRS port(s) in the DMRS configuration, and some of the DMRS port(s) are configured via a separate higher layer signal.

[0547] The terminal receives an indication of one DMRS port from among the available DMRS port(s) in the PTRS-DMRS association field and uses the DMRS port for PTRS transmission. The PTRS-DMRS association field indicates one value from among 'DMRS port 0', 'DMRS port 1', 'DMRS port 2', ... in ascending order. For example, if the PTRS-DMRS association field indicates 'DMRS port 3', the terminal uses DMRS port(s) 3 as the antenna port for PTRS transmission.

[0548] In this embodiment, the length of the PTRS-DMRS association field is determined by the number of available DMRS port(s). For example, the length of the PTRS-DMRS association field is determined by ceil(log2(the number of available DMRS port(s))).

[0549] The PTRS-DMRS association field indicates a PTRS antenna port of a certain mapping type, and this PTRS antenna port is used for all PUSCHs.

[0550] The terminal receives an indication of one of the DMRS port(s) scheduled for a different mapping type from the PTRS-DMRS association field, and uses one DMRS port for PTRS transmission based on the indication. However, in one embodiment, the terminal receives an indication of one of the DMRS port(s) scheduled for one mapping type from the PTRS-DMRS association field, and transmits the PTRS at the antenna port obtained through the indication. The terminal also transmits the PTRS for the other mapping type at the same antenna port obtained through the indication.

[0551] When the terminal is indicated with TDRA rows of different mapping types, it selects one of mapping type A and mapping type B to apply the PTRS-DMRS association field. For example, the selection is based on at least one of the following:

[0552] The terminal always selects mapping type A. That is, the PTRS-DMRS association field indicates one of the DMRS port(s) of mapping type A.

[0553] The terminal always selects mapping type B. That is, the PTRS-DMRS association field indicates one of the DMRS port(s) of mapping type B.

[0554] The terminal selects the mapping type of the first scheduled PUSCH. That is, the PTRS-DMRS association field indicates one of the DMRS port(s) of the mapping type of the first scheduled PUSCH. Here, the first scheduled PUSCH is the PUSCH scheduled at the earliest position in time. Here, the first scheduled PUSCH is the PUSCH corresponding to the scheduling information set first from the higher layer in the indicated TDRA row.

[0555] Assume that the terminal receives {3,4,5} as the DMRS port(s) of mapping type A and {2,3,6} as the DMRS port(s) of mapping type B. Here, mapping type A is the case where the DMRS type (dmrs-Type) is 2, the maximum DMRS length (maxLength) is 2, the rank is 3, and the row corresponding to value2 is specified in the Antenna port table. Mapping type B is the case where the DMRS type (dmrs-Type) is 1, the maximum DMRS length (maxLength) is 2, the rank is 3, and the row corresponding to value2 is specified in the Antenna port table.

[0556] The terminal receives an indication of one of the DMRS port(s) of the mapping type selected in the PTRS-DMRS association field and uses the DMRS port for PTRS transmission. The PTRS-DMRS association field indicates one of the values ​​'1st scheduled DMRS port', '2nd scheduled DMRS port', '3rd scheduled DMRS port', and '4th scheduled DMRS port', in ascending order. For example, when the selected mapping type is mapping type A, if the scheduled DMRS port(s) is {3,4,5} and the PTRS-DMRS association field indicates the '1st scheduled DMRS port', the terminal uses DMRS port(s) 3 as the antenna port for PTRS transmission. If the PTRS-DMRS association field indicates the '2nd scheduled DMRS port', the terminal uses DMRS port(s) 4 as the antenna port for PTRS transmission. If the PTRS-DMRS association field indicates '3rd scheduled DMRS port', the terminal uses DMRS port(s) 5 as the antenna port for PTRS transmission.

[0557] If the antenna port is included in all scheduled DMRS port(s) of two different mapping types, the PTRS is transmitted through the antenna port. However, the determined antenna port may be included in the scheduled DMRS port(s) of one mapping type, but not included in the scheduled DMRS port(s) of the other mapping type. In this case, the UE performs the following operations.

[0558] As a first operation, if the determined anetnna port is not included in the scheduled DMRS port(s) of another mapping type, the PTRS is not transmitted on the PUSCH of the mapping type. That is, the PTRS is transmitted only in the case of one mapping type.

[0559] As a second operation, if the determined anetnna port is not included in the scheduled DMRS port(s) of another mapping type, the PTRS is transmitted on a specific DMRS port in the PUSCH of the mapping type, where the specific DMRS port is the DMRS port with the lowest index among the scheduled DMRS ports.

[0560] Although the embodiments have been described above in a divided manner, this is for convenience of explanation, and the embodiments may be combined for implementation. Also, in various embodiments of the present invention, the operation of the terminal has been described for convenience of explanation, but the technical features of various embodiments of the present invention described in the operation of the terminal are also applicable to the configuration and operation of the base station.

[0561] Although a specific embodiment for the interpretation of the antenna port-related field and a specific embodiment for the interpretation of the PTRS-related field have been described separately above, this is only for convenience of description, and the embodiments for the interpretation of the antenna port-related field and the interpretation of the PTRS-related field may be implemented together. Also, it should be noted that the expression "embodiment" is also only for convenience of description, and the embodiments may be selectively combined within a non-inconsistent range.

[0562] FIG. 14 is a diagram illustrating the structure of a terminal in a wireless communication system according to an embodiment.

[0563] Referring to FIG. 14, the terminal includes a transceiver, referred to as a terminal receiver 1400 and a terminal transmitter 1410, a memory (not shown), and a terminal processor 1405 (or a terminal controller or processor). The transceivers (1400, 1410), memory, and terminal processor 1405 of the terminal operate according to the terminal communication method described above. However, the components of the terminal are not limited to the above examples. For example, the terminal may include more or fewer components than those described above. In addition, the transceiver, memory, and processor may be embodied in the form of a single chip.

[0564] The transceiver transmits and receives signals to and from the base station. Here, the signals include control information and data. To this end, the transceiver includes an RF transmitter that up-converts and amplifies the frequency of a signal to be transmitted, an RF receiver that performs low-noise amplification and down-converts the frequency of a received signal, etc. However, this is only one embodiment of the transceiver, and the components of the transceiver are not limited to an RF transmitter and an RF receiver.

[0565] The transceiver receives signals through a wireless channel and outputs the signals to the processor, and transmits signals output from the processor through the wireless channel.

[0566] The memory stores programs and data necessary for the operation of the terminal. The memory also stores control information or data contained in signals transmitted and received by the terminal. The memory is composed of a storage medium such as ROM, RAM, hard disk, CD-ROM, DVD, etc., or a combination of storage media. The memory may also be multiple.

[0567] Also, the processor controls a series of processes so that the terminal operates according to the above-mentioned embodiment. For example, the processor controls the components of the terminal to receive DCI consisting of two layers and simultaneously receive multiple PDSCHs. There may be a plurality of processors, and the processor controls the components of the terminal by executing a program stored in the memory.

[0568] FIG. 15 is a diagram illustrating a structure of a base station in a wireless communication system according to one embodiment.

[0569] Referring to FIG. 15, the base station includes a transceiver unit, referred to as a base station receiver unit 1500 and a base station transmitter unit 1510, a memory (not shown), and a base station processing unit 1505 (or a base station controller or processor). The transceiver units (1500, 1510), memory, and base station processing unit 1505 of the base station operate according to the above-mentioned base station communication method. However, the components of the base station are not limited to the above-mentioned examples. For example, the base station may include more or fewer components than those described above. In addition, the transceiver unit, memory, and processor may be embodied in the form of a single chip.

[0570] The transceiver transmits and receives signals to and from the terminal. Here, the signals include control information and data. To this end, the transceiver includes an RF transmitter that up-converts and amplifies the frequency of a signal to be transmitted, an RF receiver that performs low-noise amplification and down-converts the frequency of a received signal, etc. However, this is only one embodiment of the transceiver, and the components of the transceiver are not limited to an RF transmitter and an RF receiver.

[0571] The transceiver receives signals through a wireless channel and outputs the signals to the processor, and transmits the signals output from the processor through the wireless channel.

[0572] The memory stores programs and data necessary for the operation of the base station. The memory also stores control information or data contained in signals transmitted and received by the base station. The memory is composed of a storage medium such as a ROM, a RAM, a hard disk, a CD-ROM, a DVD, etc., or a combination of storage media. Also, there may be multiple memories.

[0573] The processor controls a series of processes so that the base station operates according to the above-described embodiment of the present invention. For example, the processor configures two-layer DCI including allocation information for multiple PDSCHs and controls each component of the base station to transmit the DCI. There may be multiple processors, and the processor controls the components of the base station by executing a program stored in the memory.

[0574] The methods according to the embodiments described in the claims or specification of the present invention may be implemented in the form of hardware, software, or a combination of hardware and software.

[0575] In the case of a software implementation, a computer-readable recording medium having one or more programs (software modules) recorded thereon is provided. The one or more programs recorded on the computer-readable recording medium are configured for execution by one or more processors in an electronic device. The one or more programs include instructions for causing the electronic device to execute a method according to an embodiment of the present invention as described in the claims or specification.

[0576] Such programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), magnetic disc storage device, Compact Disc-ROM (CD-ROM), Digital Versatile Discs (DVDs), or other forms of optical storage devices, magnetic cassettes, or in memory configured as a combination of some or all of these. Also, each of the constituent memories may be included in multiples.

[0577] The program may be stored in an attachable storage device that is accessed through a communication network such as the Internet, an Intranet, a Local Area Network (LAN), a Wide LAN (WLAN), or a Storage Area Network (SAN), or a combination of these. Such a storage device is connected to a device that executes an embodiment of the present invention through an external port. Also, a separate storage device on the communication network may be connected to a device that executes an embodiment of the present invention.

[0578] In the above-described specific embodiments of the present invention, the components included in the present invention are expressed as singular or plural according to the specific embodiments presented. However, the expressions singular or plural are selected to suit the circumstances presented for convenience of description, and the present invention is not limited to singular or plural components, and even components expressed as plural may be composed of singular, and even components expressed as singular may be composed of plural.

[0579] Meanwhile, the embodiments of the present invention disclosed in the present specification and drawings are merely specific examples presented to easily explain the contents of the present invention and to facilitate understanding of the present invention, and are not intended to limit the scope of the present invention. That is, it is obvious to a person having ordinary skill in the art to which the present invention belongs that other modifications based on the technical idea of ​​the present invention can be implemented. In addition, each embodiment can be operated in combination with each other as necessary. For example, a base station and a terminal are operated by combining parts of one embodiment different from one embodiment of the present invention with each other. For example, a base station and a terminal are operated by combining parts of the first embodiment and the second embodiment of the present invention with each other. In addition, although the embodiment of the present invention has been presented based on the FDD LTE system, other modifications based on the technical idea of ​​the present embodiment can be implemented in other systems such as a TDD LTE system, a 5G or an NR system.

[0580] Meanwhile, in the figures illustrating the method of the present invention, the illustrated steps do not necessarily correspond to the steps of execution, and the order may be changed or the steps may be executed in parallel.

[0581] Alternatively, a drawing explaining the method of the present invention may include only some of the components, with some components being omitted, as long as the essence of the present invention is not impaired.

[0582] Furthermore, the method of the present invention may be implemented by combining part or all of the contents included in each embodiment within the scope that does not detract from the essence of the present invention.

[0583] Although various embodiments of the present invention have been described above, the above description of the present specification is for illustrative purposes only, and the embodiments of the present invention are not limited to the disclosed embodiments. Those skilled in the art will understand that the present invention can be easily modified into other specific forms without changing the technical idea or essential features of the present invention. The scope of the present invention is indicated by the claims below rather than the detailed description, and all modifications or alterations derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention. [Explanation of symbols]

[0584] 101 Resource Element (RE) 102, 501 Orthogonal Frequency Division Multiplexing (OFDM) symbols 103 Subcarrier 104 Resource Block (RB) 110, 201 Subframe 200 Frame 202, 203, 420 Slot 300 UE bandwidth 301 Bandwidth Part #1 (BWP#1) 302 Bandwidth Part #2 (BWP#2) 401 Control Area #1 402 Control Area #2 403 Frequency Resources 404 Control Resource Set Duration 410 UE bandwidth part 502 Physical Resource Block (PRB) 503 Resource Element Group (REG) 504 Control Channel Element (CCE) 505 Demodulation Reference Signal (DMRS: Demodulation Reference signal) 601 Downlink Data Channel 602 rate matching resources 603 Time Domain Resource Allocation Information 604 Frequency domain resource allocation information 605 Periodicity information 1100, 1110, 1120 Physical Downlink Control Channel (PDCCH) 1101, 1102, 1103, 1104, 1111, 1112, 1121, 1301, 1302, 1303, 1304 Physical downlink data channel (PDSCH: physical downlink shared channel) 1200 Time domain resource assignment (TDRA) field 1205, 1255 modulation coding scheme (MCS) field 1210, 1260, 1261 New Data Indicator (NDI) Fields 1215, 1262, 1263 Redundancy version (RV) fields 1220, 1270 Hybrid automatic repeat request (HARQ) field 1225, 1275 Antenna port(s) field 1230, 1280 DMRS sequence initialization field 1235 padding bits 1305 Physical Uplink Control Channel (PUCCH) 1400 Terminal receiver 1405 Terminal processing unit 1410 Terminal transmitter 1500 Base station receiver 1505 Base station processing unit 1510 Base station transmitter

Claims

1. A method performed by a terminal in a wireless communication system, comprising: receiving, from a base station, time domain resource allocation (TDRA) information for a plurality of cells; receiving, from the base station, downlink control information (DCI) including an antenna port field for scheduling a TDRA field and a physical downlink shared channel (PDSCH) for the plurality of cells; when a first method is used for the antenna port field, applying the value of the antenna port field to each of the plurality of cells.

2. The method according to claim 1, wherein when a second method is used for the antenna port field, a first bit field of the antenna port field is applied to a first cell among the plurality of cells, and a second bit field of the antenna port field is applied to a second cell among the plurality of cells.

3. when the first method is used for the antenna port field, the number of bits of the antenna port field is determined based on a maximum number of bits for a plurality of antenna port tables for the plurality of cells; when the second method is used for the antenna port field, the number of bits of the antenna port field is determined based on a sum of the number of bits of each of the plurality of antenna port tables for the plurality of cells; The method according to claim 2, wherein the DCI further includes information for identifying the plurality of cells. According to claim 4, the method further includes receiving, from the base station, another DCI including another TDRA field, another antenna port field, and a phase tracking reference signal (PTRS) - demodulation reference signal (DMRS) related field for scheduling the physical uplink shared channel (PUSCH) of the plurality of cells, the PTRS - DMRS related field includes a first bit field for a first cell among the plurality of cells and a second bit field for a second cell among the plurality of cells, The method according to claim 1, wherein the size of the first bit field is 2 bits and the size of the second bit field is 2 bits.

5. A method performed by a base station in a wireless communication system, transmitting time domain resource allocation (TDRA) information for a plurality of cells to a terminal, transmitting downlink control information (DCI) including a TDRA field and an antenna port field for scheduling a physical downlink shared channel (PDSCH) for the plurality of cells to the terminal, When a first method is used for the antenna port field, the value of the antenna port field is applied to each of the plurality of cells.

6. The method according to claim 5, wherein when a second method is used for the antenna port field, a first bit field of the antenna port field is applied to a first cell among the plurality of cells, and a second bit field of the antenna port field is applied to a second cell among the plurality of cells.

7. When the first method is used for the antenna port field, the number of bits of the antenna port field is determined based on the maximum number of bits for a plurality of antenna port tables for the plurality of cells, When the second method is used for the antenna port field, the number of bits of the antenna port field is determined based on the sum of the number of bits of each of the plurality of antenna port tables for the plurality of cells. The method according to claim 6, wherein the DCI further includes information for identifying the plurality of cells. **Claim 8** The method further includes transmitting, to the terminal, another DCI including another TDRA field, another antenna port field, and a phase tracking reference signal (PTRS) - demodulation reference signal (DMRS) related field for scheduling a physical uplink shared channel (PUSCH) of the plurality of cells. The PTRS - DMRS related field includes a first bit field for a first cell among the plurality of cells and a second bit field for a second cell among the plurality of cells. The method according to claim 5, wherein the size of the first bit field is 2 bits and the size of the second bit field is 2 bits. **Claim 9** A terminal in a wireless communication system, including a transceiver, and a control unit, wherein the control unit receives time domain resource allocation (TDRA) information for a plurality of cells from a base station, receives downlink control information (DCI) including a TDRA field and an antenna port field for scheduling a physical downlink shared channel (PDSCH) of the plurality of cells from the base station, and controls to apply the value of the antenna port field to each of the plurality of cells when a first method is used for the antenna port field. **Claim 10** When a second method is used for the antenna port field, a first bit field of the antenna port field is applied to a first cell among the plurality of cells, and a second bit field of the antenna port field is applied to a second cell among the plurality of cells. The terminal according to claim 9, characterized in that

11. When the first method is used for the antenna port field, the number of bits of the antenna port field is determined based on the maximum number of bits for a plurality of antenna port tables for the plurality of cells. When the second method is used for the antenna port field, the number of bits of the antenna port field is determined based on the sum of the number of bits of each of the plurality of antenna port tables for the plurality of cells. The DCI further includes information for identifying the plurality of cells. The terminal according to claim 10, characterized in that

12. The control unit is further controlled to receive from the base station another DCI including another TDRA field, another antenna port field, and a phase tracking reference signal (PTRS) - demodulation reference signal (DMRS) related field for scheduling a physical uplink shared channel (PUSCH) of the plurality of cells. The PTRS - DMRS related field includes a first bit field for a first cell among the plurality of cells and a second bit field for a second cell among the plurality of cells. The size of the first bit field is 2 bits, and the size of the second bit field is 2 bits. The terminal according to claim 9, characterized in that

13. A base station in a wireless communication system, comprising: A transceiver unit; A control unit, and The control unit: Transmits time domain resource allocation (TDRA) information for a plurality of cells to a terminal. Control to transmit downlink control information (DCI) including an antenna port field for scheduling a TDRA field and a physical downlink shared channel (PDSCH) for the plurality of cells to the terminal, When a first method is used for the antenna port field, the value of the antenna port field is applied to each of the plurality of cells, characterized by a base station. **Claim 14** When a second method is used for the antenna port field, a first bit field of the antenna port field is applied to a first cell among the plurality of cells, and a second bit field of the antenna port field is applied to a second cell among the plurality of cells. The base station according to claim 13, characterized in that **Claim 15** When the first method is used for the antenna port field, the number of bits of the antenna port field is determined based on the maximum number of bits for a plurality of antenna port tables for the plurality of cells, When the second method is used for the antenna port field, the number of bits of the antenna port field is determined based on the sum of the number of bits of each of a plurality of antenna port tables for the plurality of cells, The DCI further includes information for identifying the plurality of cells. The base station according to claim 14, characterized in that **Claim 16** The control unit is further controlled to transmit another DCI including another TDRA field, another antenna port field, and a phase tracking reference signal (PTRS) - demodulation reference signal (DMRS) related field for scheduling a physical uplink shared channel (PUSCH) of the plurality of cells to the terminal, The PTRS - DMRS related field includes a first bit field for a first cell among the plurality of cells and a second bit field for a second cell among the plurality of cells, The base station according to claim 13, wherein the size of the first bit field is 2 bits, and the size of the second bit field is 2 bits.

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